1
|
Nelson NG, Burke SE, Cappelli L, Matlack LE, Smith AP, Francois N, Lombardo JF, Shah YB, Wen KY, Shafi AA, Simone NL. Temporal Considerations in Brain Metastases Radiation Therapy: The Intersection of Chronobiology and Patient Profiles. Clocks Sleep 2024; 6:200-210. [PMID: 38534802 DOI: 10.3390/clockssleep6010014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 02/29/2024] [Accepted: 03/18/2024] [Indexed: 03/28/2024] Open
Abstract
The circadian system, a vital temporal regulator influencing physiological processes, has implications for cancer development and treatment response. Our study assessed circadian timing's impact on whole-brain radiotherapy outcomes in brain metastases for personalized cancer therapy insights. The aim of the study was to evaluate circadian influence on radiation treatment timing and its correlation with clinical outcomes and to identify patient populations benefiting from interventions synchronizing circadian rhythms, considering subgroup differences and potential disparities. An IRB-approved retrospective analysis of 237 patients undergoing whole-brain radiotherapy for brain metastases (2017-2021), receiving over 80% of treatments in the morning or afternoon, was performed. Survival analyses utilized Kaplan-Meier curves. This was a single-institution study involving patients receiving whole-brain radiotherapy. Demographic, disease, and socioeconomic parameters from electronic medical records were collected. Morning treatment (n = 158) showed a trend toward improved overall survival vs. afternoon (n = 79); the median survival was 158 vs. 79 days (p = 0.20, HR = 0.84, CI95% 0.84-0.91). Subgroup benefits for morning treatment in females (p = 0.04) and trends in controlled primary disease (p = 0.11) and breast cancer metastases (p = 0.08) were observed. Black patients exhibited diminished circadian influence. The present study emphasized chronobiological factors' relevance in brain metastases radiation therapy. Morning treatment correlated with improved survival, particularly in specific subgroups. Potential circadian influence disparities were identified, laying a foundation for personalized cancer therapy and interventions synchronizing circadian rhythms for enhanced treatment efficacy.
Collapse
Affiliation(s)
- Nicolas G Nelson
- Department of Radiation Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Sara E Burke
- Department of Radiation Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Louis Cappelli
- Department of Radiation Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Lauren E Matlack
- Department of Radiation Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Alexandria P Smith
- Department of Radiation Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Noelle Francois
- Department of Radiation Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Joseph F Lombardo
- Department of Radiation Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Yash B Shah
- Department of Radiation Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Kuang-Yi Wen
- Division of Population Health, Department of Medical Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Ayesha A Shafi
- Center for Prostate Disease Research, Murtha Cancer Center Research Program, Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD 20817, USA
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD 20817, USA
| | - Nicole L Simone
- Department of Radiation Oncology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| |
Collapse
|
2
|
Chen G, Tang Q, Yu S, Shen Y, Sun J, Peng J, Yin Y, Feng G, Lu X, Mei G, Zhang Y, Wan Q, Zhang L, Chen L. Developmental growth plate cartilage formation suppressed by artificial light at night via inhibiting BMAL1-driven collagen hydroxylation. Cell Death Differ 2023; 30:1503-1516. [PMID: 37029304 PMCID: PMC10244380 DOI: 10.1038/s41418-023-01152-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 02/20/2023] [Accepted: 03/15/2023] [Indexed: 04/09/2023] Open
Abstract
Exposure to artificial light at night (LAN) can induce obesity, depressive disorder and osteoporosis, but the pernicious effects of excessive LAN exposure on tissue structure are poorly understood. Here, we demonstrated that artificial LAN can impair developmental growth plate cartilage extracellular matrix (ECM) formation and cause endoplasmic reticulum (ER) dilation, which in turn compromises bone formation. Excessive LAN exposure induces downregulation of the core circadian clock protein BMAL1, which leads to collagen accumulation in the ER. Further investigations suggest that BMAL1 is the direct transcriptional activator of prolyl 4-hydroxylase subunit alpha 1 (P4ha1) in chondrocytes, which orchestrates collagen prolyl hydroxylation and secretion. BMAL1 downregulation induced by LAN markedly inhibits proline hydroxylation and transport of collagen from ER to golgi, thereby inducing ER stress in chondrocytes. Restoration of BMAL1/P4HA1 signaling can effectively rescue the dysregulation of cartilage formation within the developmental growth plate induced by artificial LAN exposure. In summary, our investigations suggested that LAN is a significant risk factor in bone growth and development, and a proposed novel strategy targeting enhancement of BMAL1-mediated collagen hydroxylation could be a potential therapeutic approach to facilitate bone growth.
Collapse
Affiliation(s)
- Guangjin Chen
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Qingming Tang
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Shaoling Yu
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Yufeng Shen
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Jiwei Sun
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Jinfeng Peng
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Ying Yin
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Guangxia Feng
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Xiaofeng Lu
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Gang Mei
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Yifan Zhang
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China
| | - Qian Wan
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Luoying Zhang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Lili Chen
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
- School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China.
| |
Collapse
|
3
|
Loh D, Reiter RJ. Melatonin: Regulation of Viral Phase Separation and Epitranscriptomics in Post-Acute Sequelae of COVID-19. Int J Mol Sci 2022; 23:8122. [PMID: 35897696 PMCID: PMC9368024 DOI: 10.3390/ijms23158122] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/09/2022] [Accepted: 07/20/2022] [Indexed: 01/27/2023] Open
Abstract
The relentless, protracted evolution of the SARS-CoV-2 virus imposes tremendous pressure on herd immunity and demands versatile adaptations by the human host genome to counter transcriptomic and epitranscriptomic alterations associated with a wide range of short- and long-term manifestations during acute infection and post-acute recovery, respectively. To promote viral replication during active infection and viral persistence, the SARS-CoV-2 envelope protein regulates host cell microenvironment including pH and ion concentrations to maintain a high oxidative environment that supports template switching, causing extensive mitochondrial damage and activation of pro-inflammatory cytokine signaling cascades. Oxidative stress and mitochondrial distress induce dynamic changes to both the host and viral RNA m6A methylome, and can trigger the derepression of long interspersed nuclear element 1 (LINE1), resulting in global hypomethylation, epigenetic changes, and genomic instability. The timely application of melatonin during early infection enhances host innate antiviral immune responses by preventing the formation of "viral factories" by nucleocapsid liquid-liquid phase separation that effectively blockades viral genome transcription and packaging, the disassembly of stress granules, and the sequestration of DEAD-box RNA helicases, including DDX3X, vital to immune signaling. Melatonin prevents membrane depolarization and protects cristae morphology to suppress glycolysis via antioxidant-dependent and -independent mechanisms. By restraining the derepression of LINE1 via multifaceted strategies, and maintaining the balance in m6A RNA modifications, melatonin could be the quintessential ancient molecule that significantly influences the outcome of the constant struggle between virus and host to gain transcriptomic and epitranscriptomic dominance over the host genome during acute infection and PASC.
Collapse
Affiliation(s)
- Doris Loh
- Independent Researcher, Marble Falls, TX 78654, USA;
| | - Russel J. Reiter
- Department of Cell Systems and Anatomy, UT Health San Antonio, San Antonio, TX 78229, USA
| |
Collapse
|
4
|
Yang N, Srivastav SP, Rahman R, Ma Q, Dayama G, Li S, Chinen M, Lei EP, Rosbash M, Lau NC. Transposable element landscapes in aging Drosophila. PLoS Genet 2022; 18:e1010024. [PMID: 35239675 PMCID: PMC8893327 DOI: 10.1371/journal.pgen.1010024] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 01/10/2022] [Indexed: 11/28/2022] Open
Abstract
Genetic mechanisms that repress transposable elements (TEs) in young animals decline during aging, as reflected by increased TE expression in aged animals. Does increased TE expression during aging lead to more genomic TE copies in older animals? To address this question, we quantified TE Landscapes (TLs) via whole genome sequencing of young and aged Drosophila strains of wild-type and mutant backgrounds. We quantified TLs in whole flies and dissected brains and validated the feasibility of our approach in detecting new TE insertions in aging Drosophila genomes when small RNA and RNA interference (RNAi) pathways are compromised. We also describe improved sequencing methods to quantify extra-chromosomal DNA circles (eccDNAs) in Drosophila as an additional source of TE copies that accumulate during aging. Lastly, to combat the natural progression of aging-associated TE expression, we show that knocking down PAF1, a conserved transcription elongation factor that antagonizes RNAi pathways, may bolster suppression of TEs during aging and extend lifespan. Our study suggests that in addition to a possible influence by different genetic backgrounds, small RNA and RNAi mechanisms may mitigate genomic TL expansion despite the increase in TE transcripts during aging. Transposable elements, also called transposons, are genetic parasites found in all animal genomes. Normally, transposons are compacted away in silent chromatin in young animals. But, as animals age and transposon-silencing defense mechanisms break down, transposon RNAs accumulate to significant levels in old animals like fruit flies. An open question is whether the increased levels of transposon RNAs in older animals also correspond to increased genomic copies of transposons. This study approached this question by sequencing the whole genomes of young and old wild-type and mutant flies lacking a functional RNA interference (RNAi) pathway, which naturally silences transposon RNAs. Although the wild-type flies with intact RNAi activity had little new accumulation of transposon copies, the sequencing approach was able to detect several transposon accumulation occurrences in some RNAi mutants. In addition, we found that some fly transposon families can also accumulate as extra-chromosomal circular DNA copies. Lastly, we showed that genetically augmenting the expression of RNAi factors can counteract the rising transposon RNA levels in aging and promote longevity. This study improves our understanding of the animal host genome relationship with transposons during natural aging processes.
Collapse
Affiliation(s)
- Nachen Yang
- Boston University School of Medicine, Department of Biochemistry, Boston, Massachusetts, United States of America
| | - Satyam P. Srivastav
- Boston University School of Medicine, Department of Biochemistry, Boston, Massachusetts, United States of America
| | - Reazur Rahman
- Brandeis University, Department of Biology and Howard Hughes Medical Institute, Waltham, Massachusetts, United States of America
| | - Qicheng Ma
- Boston University School of Medicine, Department of Biochemistry, Boston, Massachusetts, United States of America
| | - Gargi Dayama
- Boston University School of Medicine, Department of Biochemistry, Boston, Massachusetts, United States of America
| | - Sizheng Li
- Boston University School of Medicine, Department of Biochemistry, Boston, Massachusetts, United States of America
| | - Madoka Chinen
- Nuclear Organization and Gene Expression Section, NIDDK, NIH, Bethesda, Maryland, United States of America
| | - Elissa P. Lei
- Nuclear Organization and Gene Expression Section, NIDDK, NIH, Bethesda, Maryland, United States of America
| | - Michael Rosbash
- Brandeis University, Department of Biology and Howard Hughes Medical Institute, Waltham, Massachusetts, United States of America
| | - Nelson C. Lau
- Boston University School of Medicine, Department of Biochemistry, Boston, Massachusetts, United States of America
- Boston University Genome Science Institute, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
5
|
Chronoradiobiology of Breast Cancer: The Time Is Now to Link Circadian Rhythm and Radiation Biology. Int J Mol Sci 2022; 23:ijms23031331. [PMID: 35163264 PMCID: PMC8836288 DOI: 10.3390/ijms23031331] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/20/2022] [Accepted: 01/23/2022] [Indexed: 12/13/2022] Open
Abstract
Circadian disruption has been linked to cancer development, progression, and radiation response. Clinical evidence to date shows that circadian genetic variation and time of treatment affect radiation response and toxicity for women with breast cancer. At the molecular level, there is interplay between circadian clock regulators such as PER1, which mediates ATM and p53-mediated cell cycle gating and apoptosis. These molecular alterations may govern aggressive cancer phenotypes, outcomes, and radiation response. Exploiting the various circadian clock mechanisms may enhance the therapeutic index of radiation by decreasing toxicity, increasing disease control, and improving outcomes. We will review the body’s natural circadian rhythms and clock gene-regulation while exploring preclinical and clinical evidence that implicates chronobiological disruptions in the etiology of breast cancer. We will discuss radiobiological principles and the circadian regulation of DNA damage responses. Lastly, we will present potential rational therapeutic approaches that target circadian pathways to improve outcomes in breast cancer. Understanding the implications of optimal timing in cancer treatment and exploring ways to entrain circadian biology with light, diet, and chronobiological agents like melatonin may provide an avenue for enhancing the therapeutic index of radiotherapy.
Collapse
|
6
|
Dauchy RT, Hill SM, Blask DE. A Method for Perfusion of Tissue-Isolated Human Tumor Xenografts in Nude Rats to Investigate the Oncostatic Role of the Physiological Nocturnal Melatonin Signal. Methods Mol Biol 2022; 2550:477-488. [PMID: 36180715 DOI: 10.1007/978-1-0716-2593-4_46] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The tissue-isolated human tumor perfusion methodology enables the elucidation of physiological melatonin's oncostatic impact on cancer metabolism and physiology. Here we describe an apparatus and surgical technique for perfusing tissue-isolated human tumor xenografts in nude rats in situ that ensures continuous blood flow to and from the tissue. This system and methodology have proven quite successful in examining the receptor-mediated oncostatic effects of the physiological nocturnal melatonin signal on metabolism and physiology in a variety of epithelial and mesenchymal human tumors.
Collapse
Affiliation(s)
- Robert T Dauchy
- Department of Structural and Cellular Biology, Tulane University School of Medicine, Louisiana Cancer Research Consortium, New Orleans, LA, USA.
| | - Steven M Hill
- Department of Structural and Cellular Biology, Tulane University School of Medicine, Louisiana Cancer Research Consortium, New Orleans, LA, USA
| | - David E Blask
- Department of Structural and Cellular Biology, Tulane University School of Medicine, Louisiana Cancer Research Consortium, New Orleans, LA, USA
| |
Collapse
|
7
|
Megerian MF, Kim JS, Badreddine J, Hong SH, Ponsky LE, Shin JI, Ghayda RA. Melatonin and Prostate Cancer: Anti-tumor Roles and Therapeutic Application. Aging Dis 2022; 14:840-857. [PMID: 37191417 DOI: 10.14336/ad.2022.1010] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 10/10/2022] [Indexed: 11/18/2022] Open
Abstract
Melatonin is an endogenous indoleamine that has been shown to inhibit tumor growth in laboratory models of prostate cancer. Prostate cancer risk has additionally been associated with exogenous factors that interfere with normal pineal secretory activity, including aging, poor sleep, and artificial light at night. Therefore, we aim to expand on the important epidemiological evidence, and to review how melatonin can impede prostate cancer. More specifically, we describe the currently known mechanisms of melatonin-mediated oncostasis in prostate cancer, including those that relate to the indolamine's ability to modulate metabolic activity, cell cycle progression and proliferation, androgen signaling, angiogenesis, metastasis, immunity and oxidative cell status, apoptosis, genomic stability, neuroendocrine differentiation, and the circadian rhythm. The outlined evidence underscores the need for clinical trials to determine the efficacy of supplemental, adjunct, and adjuvant melatonin therapy for the prevention and treatment of prostate cancer.
Collapse
|
8
|
Sides MB, Johnston SL, Sirek A, Lee PH, Blue RS, Antonsen EL, Basner M, Douglas GL, Epstein A, Flynn-Evans EE, Gallagher MB, Hayes J, Lee SMC, Lockley SW, Monseur B, Nelson NG, Sargsyan A, Smith SM, Stenger MB, Stepanek J, Zwart SR. Bellagio II Report: Terrestrial Applications of Space Medicine Research. Aerosp Med Hum Perform 2021; 92:650-669. [PMID: 34503618 DOI: 10.3357/amhp.5843.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
AbstractINTRODUCTION: For over 50 yr, investigators have studied the physiological adaptations of the human system during short- and long-duration spaceflight exposures. Much of the knowledge gained in developing health countermeasures for astronauts onboard the International Space Station demonstrate terrestrial applications. To date, a systematic process for translating these space applications to terrestrial human health has yet to be defined.METHODS: In the summer of 2017, a team of 38 international scientists launched the Bellagio ll Summit Initiative. The goals of the Summit were: 1) To identify space medicine findings and countermeasures with highest probability for future terrestrial applications; and 2) To develop a roadmap for translation of these countermeasures to future terrestrial application. The team reviewed public domain literature, NASA databases, and evidence books within the framework of the five-stage National Institutes of Health (NIH) translation science model, and the NASA two-stage translation model. Teams then analyzed and discussed interdisciplinary findings to determine the most significant evidence-based countermeasures sufficiently developed for terrestrial application.RESULTS: Teams identified published human spaceflight research and applied translational science models to define mature products for terrestrial clinical practice.CONCLUSIONS: The Bellagio ll Summit identified a snapshot of space medicine research and mature science with the highest probability of translation and developed a Roadmap of terrestrial application from space medicine-derived countermeasures. These evidence-based findings can provide guidance regarding the terrestrial applications of best practices, countermeasures, and clinical protocols currently used in spaceflight.Sides MB, Johnston SL III, Sirek A, Lee PH, Blue RS, Antonsen EL, Basner M, Douglas GL, Epstein A, Flynn-Evans EE, Gallagher MB, Hayes J, Lee SMC, Lockley SW, Monseur B, Nelson NG, Sargsyan A, Smith SM, Stenger MB, Stepanek J, Zwart SR; Bellagio II Team. Bellagio II report: terrestrial applications of space medicine research. Aerosp Med Hum Perform. 2021; 92(8):650669.
Collapse
|
9
|
Stow EC, Kaul T, deHaro DL, Dem MR, Beletsky AG, Morales ME, Du Q, LaRosa AJ, Yang H, Smither E, Baddoo M, Ungerleider N, Deininger P, Belancio VP. Organ-, sex- and age-dependent patterns of endogenous L1 mRNA expression at a single locus resolution. Nucleic Acids Res 2021; 49:5813-5831. [PMID: 34023901 PMCID: PMC8191783 DOI: 10.1093/nar/gkab369] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 04/21/2021] [Accepted: 04/28/2021] [Indexed: 11/13/2022] Open
Abstract
Expression of L1 mRNA, the first step in the L1 copy-and-paste amplification cycle, is a prerequisite for L1-associated genomic instability. We used a reported stringent bioinformatics method to parse L1 mRNA transcripts and measure the level of L1 mRNA expressed in mouse and rat organs at a locus-specific resolution. This analysis determined that mRNA expression of L1 loci in rodents exhibits striking organ specificity with less than 0.8% of loci shared between organs of the same organism. This organ specificity in L1 mRNA expression is preserved in male and female mice and across age groups. We discovered notable differences in L1 mRNA expression between sexes with only 5% of expressed L1 loci shared between male and female mice. Moreover, we report that the levels of total L1 mRNA expression and the number and spectrum of expressed L1 loci fluctuate with age as independent variables, demonstrating different patterns in different organs and sexes. Overall, our comparisons between organs and sexes and across ages ranging from 2 to 22 months establish previously unforeseen dynamic changes in L1 mRNA expression in vivo. These findings establish the beginning of an atlas of endogenous L1 mRNA expression across a broad range of biological variables that will guide future studies.
Collapse
Affiliation(s)
- Emily C Stow
- Tulane Cancer Center, Tulane Health Sciences Center, 1700 Tulane Ave, New Orleans, LA 70112, USA.,Department of Structural and Cellular Biology, Tulane School of Medicine, 1430 Tulane Ave, New Orleans, LA 70112 USA
| | - Tiffany Kaul
- Tulane Cancer Center, Tulane Health Sciences Center, 1700 Tulane Ave, New Orleans, LA 70112, USA.,Department of Epidemiology, Tulane School of Public Health and Tropical Medicine, New Orleans, LA 70112 USA
| | - Dawn L deHaro
- Tulane Cancer Center, Tulane Health Sciences Center, 1700 Tulane Ave, New Orleans, LA 70112, USA.,Department of Structural and Cellular Biology, Tulane School of Medicine, 1430 Tulane Ave, New Orleans, LA 70112 USA
| | - Madeleine R Dem
- Tulane Cancer Center, Tulane Health Sciences Center, 1700 Tulane Ave, New Orleans, LA 70112, USA.,Department of Structural and Cellular Biology, Tulane School of Medicine, 1430 Tulane Ave, New Orleans, LA 70112 USA
| | - Anna G Beletsky
- Tulane Cancer Center, Tulane Health Sciences Center, 1700 Tulane Ave, New Orleans, LA 70112, USA.,Department of Structural and Cellular Biology, Tulane School of Medicine, 1430 Tulane Ave, New Orleans, LA 70112 USA
| | - Maria E Morales
- Tulane Cancer Center, Tulane Health Sciences Center, 1700 Tulane Ave, New Orleans, LA 70112, USA.,Department of Epidemiology, Tulane School of Public Health and Tropical Medicine, New Orleans, LA 70112 USA
| | - Qianhui Du
- Tulane Cancer Center, Tulane Health Sciences Center, 1700 Tulane Ave, New Orleans, LA 70112, USA.,Department of Structural and Cellular Biology, Tulane School of Medicine, 1430 Tulane Ave, New Orleans, LA 70112 USA
| | - Alexis J LaRosa
- Department of Structural and Cellular Biology, Tulane School of Medicine, 1430 Tulane Ave, New Orleans, LA 70112 USA
| | - Hanlin Yang
- Tulane Cancer Center, Tulane Health Sciences Center, 1700 Tulane Ave, New Orleans, LA 70112, USA
| | - Emily Smither
- Department of Structural and Cellular Biology, Tulane School of Medicine, 1430 Tulane Ave, New Orleans, LA 70112 USA
| | - Melody Baddoo
- Tulane Cancer Center, Tulane Health Sciences Center, 1700 Tulane Ave, New Orleans, LA 70112, USA
| | - Nathan Ungerleider
- Tulane Cancer Center, Tulane Health Sciences Center, 1700 Tulane Ave, New Orleans, LA 70112, USA
| | - Prescott Deininger
- Tulane Cancer Center, Tulane Health Sciences Center, 1700 Tulane Ave, New Orleans, LA 70112, USA.,Department of Epidemiology, Tulane School of Public Health and Tropical Medicine, New Orleans, LA 70112 USA
| | - Victoria P Belancio
- Tulane Cancer Center, Tulane Health Sciences Center, 1700 Tulane Ave, New Orleans, LA 70112, USA.,Department of Structural and Cellular Biology, Tulane School of Medicine, 1430 Tulane Ave, New Orleans, LA 70112 USA
| |
Collapse
|
10
|
Cash E, Sephton S, Woolley C, Elbehi AM, R I A, Ekine-Afolabi B, Kok VC. The role of the circadian clock in cancer hallmark acquisition and immune-based cancer therapeutics. J Exp Clin Cancer Res 2021; 40:119. [PMID: 33794967 PMCID: PMC8017624 DOI: 10.1186/s13046-021-01919-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/18/2021] [Indexed: 02/07/2023] Open
Abstract
The circadian system temporally regulates physiology to maintain homeostasis. Co-opting and disrupting circadian signals appear to be distinct attributes that are functionally important for the development of a tumor and can enable or give rise to the hallmarks that tumors use to facilitate their initiation, growth and progression. Because circadian signals are also strong regulators of immune cell proliferation, trafficking and exhaustion states, they play a role in how tumors respond to immune-based cancer therapeutics. While immuno-oncology has heralded a paradigm shift in cancer therapeutics, greater accuracy is needed to increase our capability of predicting who will respond favorably to, or who is likely to experience the troubling adverse effects of, immunotherapy. Insights into circadian signals may further refine our understanding of biological determinants of response and help answer the fundamental question of whether certain perturbations in circadian signals interfere with the activity of immune checkpoint inhibitors. Here we review the body of literature highlighting circadian disruption as a cancer promoter and synthesize the burgeoning evidence suggesting circadian signals play a role in how tumors respond to immune-based anti-cancer therapeutics. The goal is to develop a framework to advance our understanding of the relationships between circadian markers, cancer biology, and immunotherapeutics. Bolstered by this new understanding, these relationships may then be pursued in future clinical studies to improve our ability to predict which patients will respond favorably to, and avoid the adverse effects of, traditional and immune-based cancer therapeutics.
Collapse
Affiliation(s)
- Elizabeth Cash
- Department of Otolaryngology and Communicative Disorders, University of Louisville School of Medicine, James Graham Brown Cancer Center, 529 S Jackson Street, Louisville, KY, 40202, USA.
| | - Sandra Sephton
- Department of Psychological & Brain Sciences, University of Louisville, Louisville, KY, USA
| | - Cassandra Woolley
- Department of Microbiology and Immunology, University of Louisville School of Medicine, Louisville, KY, USA
| | - Attia M Elbehi
- Department of Oncology, Medical Sciences Division, University of Oxford, Oxford, UK
| | - Anu R I
- Department of Clinical Biochemistry, MVR Cancer Center and Research Institute, Kerala, India
| | - Bene Ekine-Afolabi
- ZEAB Therapeutic Ltd, London, UK
- Department of Health, Sport & Bioscience, University of East London, Stratford, UK
| | - Victor C Kok
- Department of Medical Oncology, Kuang Tien General Hospital Cancer Center, Taichung, Taiwan
- Department of Bioinformatics and Medical Engineering, Asia University Taiwan, Taichung, Taiwan
| |
Collapse
|
11
|
The evolutionary history of mariner elements in stalk-eyed flies reveals the horizontal transfer of transposons from insects into the genome of the cnidarian Hydra vulgaris. PLoS One 2020; 15:e0235984. [PMID: 32658920 PMCID: PMC7357744 DOI: 10.1371/journal.pone.0235984] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 06/25/2020] [Indexed: 11/19/2022] Open
Abstract
The stalk-eyed flies (Diopsidae, Diptera) are a family of approximately 100 species of calypterate dipterans, characterised by extended head capsules. Species within the family have previously been shown to possess six subfamilies of mariner transposons, with nucleotide substitution patterns suggesting that at least two subfamilies are currently active. The vertumnana subfamily has been shown to have been involved in a horizontal transfer event involving Diopsidae and a second dipteran family in the Tephritidae. Presented here are cloned and sequenced mariner elements from three further diopsid species, in addition to a bioinformatic analysis of mariner elements identified in transcriptomic and genomic data from the genus Teleopsis. The newly identified mariner elements predominantly fall into previously recognised subfamilies, however the publicly available Teleopsis data also revealed a novel subfamily. Three of the seven identified subfamilies are shown to have undergone horizontal transfer, two of which appear to involve diopsid donor species. One recipient group of a diopsid mariner is the Bactrocera genus of tephritid flies, the transfer of which was previously proposed in an earlier study of diopsid mariner elements. The second horizontal transfer, of the mauritiana subfamily, can be traced from the Teleopsis genus to the cnidarian Hydra vulgaris. The mauritiana elements are shown to be active in the recipient H. vulgaris and transposase expression is observed in all body tissues examined in both species. The increased diversity of diopsid mariner elements points to a minimum of four subfamilies being present in the ancestral genome. Both vertical inheritance and stochastic loss of TEs have subsequently occurred within the diopsid radiation. The TE complement of H. vulgaris contains at least two mariner subfamilies of insect origin. Despite the phylogenetic distance between donor and recipient species, both subfamilies are shown to be active and proliferating within H. vulgaris.
Collapse
|
12
|
Del Re B, Giorgi G. Long INterspersed element-1 mobility as a sensor of environmental stresses. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:465-493. [PMID: 32144842 DOI: 10.1002/em.22366] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 03/03/2020] [Accepted: 03/04/2020] [Indexed: 06/10/2023]
Abstract
Long INterspersed element (LINE-1, L1) retrotransposons are the most abundant transposable elements in the human genome, constituting approximately 17%. They move by a "copy-paste" mechanism, involving reverse transcription of an RNA intermediate and insertion of its cDNA copy at a new site in the genome. L1 retrotransposition (L1-RTP) can cause insertional mutations, alter gene expression, transduce exons, and induce epigenetic dysregulation. L1-RTP is generally repressed; however, a number of observations collected over about 15 years revealed that it can occur in response to environmental stresses. Moreover, emerging evidence indicates that L1-RTP can play a role in the onset of several neurological and oncological diseases in humans. In recent years, great attention has been paid to the exposome paradigm, which proposes that health effects of an environmental factor should be evaluated considering both cumulative environmental exposures and the endogenous processes resulting from the biological response. L1-RTP could be an endogenous process considered for this application. Here, we summarize the current understanding of environmental factors that can affect the retrotransposition of human L1 elements. Evidence indicates that L1-RTP alteration is triggered by numerous and various environmental stressors, such as chemical agents (heavy metals, carcinogens, oxidants, and drugs), physical agents (ionizing and non-ionizing radiations), and experiential factors (voluntary exercise, social isolation, maternal care, and environmental light/dark cycles). These data come from in vitro studies on cell lines and in vivo studies on transgenic animals: future investigations should be focused on physiologically relevant models to gain a better understanding of this topic.
Collapse
Affiliation(s)
- Brunella Del Re
- Department of Pharmacy and Biotechnology, Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Gianfranco Giorgi
- Department of Biological, Geological and Environmental Sciences, Alma Mater Studiorum University of Bologna, Bologna, Italy
| |
Collapse
|
13
|
Miret N, Zappia CD, Altamirano G, Pontillo C, Zárate L, Gómez A, Lasagna M, Cocca C, Kass L, Monczor F, Randi A. AhR ligands reactivate LINE-1 retrotransposon in triple-negative breast cancer cells MDA-MB-231 and non-tumorigenic mammary epithelial cells NMuMG. Biochem Pharmacol 2020; 175:113904. [PMID: 32156659 DOI: 10.1016/j.bcp.2020.113904] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 03/04/2020] [Indexed: 12/11/2022]
Abstract
Breast cancer is the most common cancer type in females worldwide. Environmental exposure to pesticides affecting hormonal homeostasis does not necessarily induce DNA mutations but may influence gene expression by disturbances in epigenetic regulation. Expression of long interspersed nuclear element-1 (LINE-1) has been associated with tumorigenesis in several cancers. In nearly all somatic cells, LINE-1 is silenced by DNA methylation in the 5́'UTR and reactivated during disease initiation and/or progression. Strong ligands of aryl hydrocarbon receptor (AhR) activate LINE-1 through the transforming growth factor-β1 (TGF-β1)/Smad pathway. Hexachlorobenzene (HCB) and chlorpyrifos (CPF), both weak AhR ligands, promote cell proliferation and migration in breast cancer cells, as well as tumor growth in rat models. In this context, our aim was to examine the effect of these pesticides on LINE-1 expression and ORF1p localization in the triple-negative breast cancer cell line MDA-MB-231 and the non-tumorigenic epithelial breast cell line NMuMG, and to evaluate the role of TGF-β1 and AhR pathways. Results show that 0.5 μM CPF and 0.005 μM HCB increased LINE-1 mRNA expression through Smad and AhR signaling in MDA-MB-231. In addition, the methylation of the first sites in 5́'UTR of LINE-1 was reduced by pesticide exposure, although the farther sites remained unaffected. Pesticides modulated ORF1p localization in MDA-MB-231: 0.005 μM HCB and 50 μM CPF increased nuclear translocation, while both induced cytoplasmic retention at 0.5 and 5 μM. Moreover, both stimulated double-strand breaks, enhancing H2AX phosphorylation, coincidentally with ORF1p nuclear localization. In NMuMG similar results were observed, since they heighten LINE-1 mRNA levels. CPF effect was through AhR and TGF-β1 signaling, whereas HCB action depends only of AhR. In addition, both pesticides increase ORF1p expression and nuclear localization. Our results provide experimental evidence that HCB and CPF exposure modify LINE-1 methylation levels and induce LINE-1 reactivation, suggesting that epigenetic mechanisms could contribute to pesticide-induced breast cancer progression.
Collapse
Affiliation(s)
- Noelia Miret
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Bioquímica Humana, Laboratorio de Efectos Biológicos de Contaminantes Ambientales, Paraguay 2155, 5to piso (CP 1121), Buenos Aires, Argentina
| | - C Daniel Zappia
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones Farmacológicas (UBA-CONICET), Laboratorio de Farmacología de Receptores, Junín 954, planta baja (CP1113), Buenos Aires, Argentina
| | - Gabriela Altamirano
- Universidad Nacional del Litoral, Facultad de Bioquímica y Ciencias Biológicas, Cátedra de Patología Humana, Instituto de Salud y Ambiente del Litoral (ISAL, UNL-CONICET), Ciudad Universitaria UNL, Paraje El Pozo (CP3000), Santa Fe, Argentina
| | - Carolina Pontillo
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Bioquímica Humana, Laboratorio de Efectos Biológicos de Contaminantes Ambientales, Paraguay 2155, 5to piso (CP 1121), Buenos Aires, Argentina
| | - Lorena Zárate
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Bioquímica Humana, Laboratorio de Efectos Biológicos de Contaminantes Ambientales, Paraguay 2155, 5to piso (CP 1121), Buenos Aires, Argentina
| | - Ayelén Gómez
- Universidad Nacional del Litoral, Facultad de Bioquímica y Ciencias Biológicas, Cátedra de Patología Humana, Instituto de Salud y Ambiente del Litoral (ISAL, UNL-CONICET), Ciudad Universitaria UNL, Paraje El Pozo (CP3000), Santa Fe, Argentina
| | - Marianela Lasagna
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Físico-Matemática, Laboratorio de Radioisótopos, Junín 954, 1er subsuelo (CP1113), Buenos Aires, Argentina
| | - Claudia Cocca
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Físico-Matemática, Laboratorio de Radioisótopos, Junín 954, 1er subsuelo (CP1113), Buenos Aires, Argentina
| | - Laura Kass
- Universidad Nacional del Litoral, Facultad de Bioquímica y Ciencias Biológicas, Cátedra de Patología Humana, Instituto de Salud y Ambiente del Litoral (ISAL, UNL-CONICET), Ciudad Universitaria UNL, Paraje El Pozo (CP3000), Santa Fe, Argentina
| | - Federico Monczor
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones Farmacológicas (UBA-CONICET), Laboratorio de Farmacología de Receptores, Junín 954, planta baja (CP1113), Buenos Aires, Argentina
| | - Andrea Randi
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Bioquímica Humana, Laboratorio de Efectos Biológicos de Contaminantes Ambientales, Paraguay 2155, 5to piso (CP 1121), Buenos Aires, Argentina.
| |
Collapse
|
14
|
Yanar K, Simsek B, Çakatay U. Integration of Melatonin Related Redox Homeostasis, Aging, and Circadian Rhythm. Rejuvenation Res 2019; 22:409-419. [DOI: 10.1089/rej.2018.2159] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Karolin Yanar
- Department of Medical Biochemistry, Cerrahpasa Faculty of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Bahadir Simsek
- Department of Medical Biochemistry, Cerrahpasa Faculty of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Ufuk Çakatay
- Department of Medical Biochemistry, Cerrahpasa Faculty of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
| |
Collapse
|
15
|
Night Shift Work, DNA Methylation and Telomere Length: An Investigation on Hospital Female Nurses. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16132292. [PMID: 31261650 PMCID: PMC6651131 DOI: 10.3390/ijerph16132292] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 06/25/2019] [Accepted: 06/26/2019] [Indexed: 01/07/2023]
Abstract
Increased breast cancer risk has been reported in some night shift (NS) workers but underlying biological mechanisms are still unclear. We assessed the association between NS work and DNA methylation of tumor suppressor (TP53, CDKN2A, BRCA1, BRCA2) and estrogen receptor (ESR1, ESR2) genes, methylation of repetitive elements (LINE-1, Alu), and telomere length (TL). Forty six female nurses employed in NS for at least two years were matched by age (30–45 years) and length of service (≥1 year) with 51 female colleagues not working in NS. Each subject underwent a semi-structured interview and gave a blood sample. We applied linear regression and spline models adjusted for age, BMI, smoking habit, oral contraceptive use, parity and marital status/age at marriage. Currently working in NS was associated with ESR1 hypomethylation (β: −1.85 (95%CI: −3.03; −0.67), p = 0.003). In current and former NS workers we observed TP53 (−0.93 (−1.73; −0.12), p = 0.03) and BRCA1 (−1.14 (−1.71; −0.58), p <0.001) hypomethylation. We found an increase between TL and number of years in NS in subjects employed in NS <12 years (0.06 (0.03; 0.09), p <0.001), while a decrease if employed in NS ≥12 years (−0.07 −0.10; −0.04), p <0.001). Our findings show NS-associated markers potentially involved in cellular aging, genomic instability, and cancer development.
Collapse
|
16
|
Freeman BT, Sokolowski M, Roy-Engel AM, Smither ME, Belancio VP. Identification of charged amino acids required for nuclear localization of human L1 ORF1 protein. Mob DNA 2019; 10:20. [PMID: 31080522 PMCID: PMC6501352 DOI: 10.1186/s13100-019-0159-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 04/10/2019] [Indexed: 01/10/2023] Open
Abstract
Background Long Interspersed Element 1 (LINE-1) is a retrotransposon that is present in 500,000 copies in the human genome. Along with Alu and SVA elements, these three retrotransposons account for more than a third of the human genome sequence. These mobile elements are able to copy themselves within the genome via an RNA intermediate, a process that can promote genome instability. LINE-1 encodes two proteins, ORF1p and ORF2p. Association of ORF1p, ORF2p and a full-length L1 mRNA in a ribonucleoprotein (RNP) particle, L1 RNP, is required for L1 retrotransposition. Previous studies have suggested that fusion of a tag to L1 proteins can interfere with L1 retrotransposition. Results Using antibodies detecting untagged human ORF1p, western blot analysis and manipulation of ORF1 sequence and length, we have identified a set of charged amino acids in the C-terminal region of ORF1p that are important in determining its subcellular localization. Mutation of 7 non-identical lysine residues is sufficient to make the resulting ORF1p to be predominantly cytoplasmic, demonstrating intrinsic redundancy of this requirement. These residues are also necessary for ORF1p to retain its association with KPNA2 nuclear pore protein. We demonstrate that this interaction is significantly reduced by RNase treatment. Using co-IP, we have also determined that human ORF1p associates with all members of the KPNA subfamily. Conclusions The prediction of NLS sequences suggested that specific sequences within ORF1p could be responsible for its subcellular localization by interacting with nuclear binding proteins. We have found that multiple charged amino acids in the C-terminus of ORF1p are involved in ORF1 subcellular localization and interaction with KPNA2 nuclear pore protein. Our data demonstrate that different amino acids can be mutated to have the same phenotypic effect on ORF1p subcellular localization, demonstrating that the net number of charged residues or protein structure, rather than their specific location, is important for the ORF1p nuclear localization. We also identified that human ORF1p interacts with all members of the KPNA family of proteins and that multiple KPNA family genes are expressed in human cell lines. Electronic supplementary material The online version of this article (10.1186/s13100-019-0159-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- B T Freeman
- 1Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70112 USA
| | - M Sokolowski
- 1Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70112 USA
| | - A M Roy-Engel
- 2Department of Epidemiology, School of Public Health and Tropical Medicine, Tulane Cancer Center, Tulane University, New Orleans, Louisiana 70112 USA
| | - M E Smither
- 1Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70112 USA
| | - V P Belancio
- 1Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70112 USA
| |
Collapse
|
17
|
Schuster M, Oberlinner C, Claus M. Shift-specific associations between age, chronotype and sleep duration. Chronobiol Int 2019; 36:784-795. [PMID: 30880475 DOI: 10.1080/07420528.2019.1586719] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The objective of this study was to examine the association of age with chronotype and sleep duration in day workers and rotating shift workers, including night shift work. Between October 2012 and February 2015, a cross-sectional study was conducted in a German chemical company. Using the "Munich ChronoType Questionnaire" (MCTQ), data about sleep onset and sleep offset during workdays and work-free days were retrieved and the chronotype was computed during regular voluntary occupational health check-ups. Associations between age and chronotype, as well as sleep duration, were assessed using linear regression analyses. Potential effect modification by the working time system was examined. Within the study period, 4,040 employees (82.3% and 17.7% were engaged in day work and rotating shift work, respectively) completed the questionnaire. Study participants were on average 41.8 years old (Min = 18.0, Max = 65.0, SD = 10.2) and predominantly male (75.4%). Mean chronotype and overall sleep duration was 03:22 (SD = 54 min) and 7.2 h (SD = 1.0 h) respectively. Older age was associated with earlier chronotype and reduced overall sleep duration in both day workers and rotating shift workers (p < 0.001 for all models). Compared to day workers, employees whom engaged in rotating shift work were later chronotypes and had overall a longer sleep duration. With older age, the difference between day and rotating shift workers regarding chronotype increased, while the difference regarding overall sleep duration decreased (pinteraction<0.005 for both models). This finding could indicate that both changes in circadian physiology and exposure to certain work schedules contribute to the age-related changes. Older rotating shift workers, with early chronotypes may have issues with night shifts, while day work and morning shifts may be best compatible to earlier chronotypes. Differences in sleep timing across age groups, might indicate that the same work hours will affect shift workers differently, dependent on their age, suggesting that more flexible and chronotype-adapted work hours could provide useful; especially for older employees. Sleep education in the form of courses and health campaigns could be a way to raise awareness of the importance of a healthy sleep pattern. This could be achieved by learning strategies to better adjust individual sleep patterns to work hours.
Collapse
Affiliation(s)
- Michael Schuster
- a Corporate Health Management, BASF SE , Ludwigshafen am Rhein , Germany
| | | | - Matthias Claus
- a Corporate Health Management, BASF SE , Ludwigshafen am Rhein , Germany
| |
Collapse
|
18
|
Jiao J, Sagnelli M, Shi B, Fang Y, Shen Z, Tang T, Dong B, Li D, Wang X. Genetic and epigenetic characteristics in ovarian tissues from polycystic ovary syndrome patients with irregular menstruation resemble those of ovarian cancer. BMC Endocr Disord 2019; 19:30. [PMID: 30866919 PMCID: PMC6416936 DOI: 10.1186/s12902-019-0356-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Accepted: 03/03/2019] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Irregular menstruation is clinically associated with an increased risk for ovarian cancer and disease-related mortality. This relationship remains poorly understood, and a mechanism explaining it has yet to be described. METHODS Ovarian tissues from women with polycystic ovary syndrome (PCOS) and regular menstruation (n = 10) or irregular menstruation (n = 10) were subjected to DNA methylation sequencing, real-time PCR array, whole-exome sequencing, and bioinformatics analysis. RESULTS We demonstrated that ovarian tissue from PCOS patients with irregular menstruation displayed global DNA hypomethylation, as well as hypomethylation at several functionally and oncologically significant regions. Furthermore, we showed that several cancer-related genes were aberrantly expressed in ovarian tissue from patients with irregular menstruation, and that their mRNA and microRNA profiles shared appreciable levels of coincidence with those from ovarian cancer tissue. We identified multiple point mutations in both the BRCA1 and MLH1 genes in patients with irregular menstruation, and predicted the potential pathogenicity of these mutations using bioinformatics analyses. CONCLUSIONS Due to the nature of ovarian cancer, it is important to broaden our understanding of the pathogenesis and risk factors of the disease. Herein, we provide the first description of a genetic and epigenetic basis for the clinical relationship between irregular menstruation and an increased risk for ovarian cancer.
Collapse
Affiliation(s)
- Jiao Jiao
- Center of Reproductive Medicine, Shengjing Hospital of China Medical University, Shenyang, 110004 China
| | - Matthew Sagnelli
- University of Connecticut School of Medicine, Farmington, CT 06030 USA
| | - Bei Shi
- Department of Physiology, College of Life Science, China Medical University, Shenyang, 110122 China
- Functional Laboratory Center, College of Basic Medical Science, China Medical University, Shenyang, 110122 China
| | - Yuanyuan Fang
- Center of Reproductive Medicine, Shengjing Hospital of China Medical University, Shenyang, 110004 China
| | - Ziqi Shen
- Center of Reproductive Medicine, Shengjing Hospital of China Medical University, Shenyang, 110004 China
| | - Tianyu Tang
- Center of Reproductive Medicine, Shengjing Hospital of China Medical University, Shenyang, 110004 China
| | - Bingying Dong
- Center of Reproductive Medicine, Shengjing Hospital of China Medical University, Shenyang, 110004 China
| | - Da Li
- Center of Reproductive Medicine, Shengjing Hospital of China Medical University, Shenyang, 110004 China
| | - Xiuxia Wang
- Center of Reproductive Medicine, Shengjing Hospital of China Medical University, Shenyang, 110004 China
| |
Collapse
|
19
|
Giudice A, Crispo A, Grimaldi M, Polo A, Bimonte S, Capunzo M, Amore A, D'Arena G, Cerino P, Budillon A, Botti G, Costantini S, Montella M. The Effect of Light Exposure at Night (LAN) on Carcinogenesis via Decreased Nocturnal Melatonin Synthesis. Molecules 2018; 23:E1308. [PMID: 29844288 PMCID: PMC6100442 DOI: 10.3390/molecules23061308] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 05/24/2018] [Accepted: 05/29/2018] [Indexed: 12/13/2022] Open
Abstract
In mammals, a master clock is located within the suprachiasmatic nucleus (SCN) of the hypothalamus, a region that receives input from the retina that is transmitted by the retinohypothalamic tract. The SCN controls the nocturnal synthesis of melatonin by the pineal gland that can influence the activity of the clock's genes and be involved in the inhibition of cancer development. On the other hand, in the literature, some papers highlight that artificial light exposure at night (LAN)-induced circadian disruptions promote cancer. In the present review, we summarize the potential mechanisms by which LAN-evoked disruption of the nocturnal increase in melatonin synthesis counteracts its preventive action on human cancer development and progression. In detail, we discuss: (i) the Warburg effect related to tumor metabolism modification; (ii) genomic instability associated with L1 activity; and (iii) regulation of immunity, including regulatory T cell (Treg) regulation and activity. A better understanding of these processes could significantly contribute to new treatment and prevention strategies against hormone-related cancer types.
Collapse
Affiliation(s)
- Aldo Giudice
- Epidemiology Unit, IRCCS Istituto Nazionale Tumori "Fondazione G. Pascale", 80131 Napoli, Italy.
| | - Anna Crispo
- Epidemiology Unit, IRCCS Istituto Nazionale Tumori "Fondazione G. Pascale", 80131 Napoli, Italy.
| | - Maria Grimaldi
- Epidemiology Unit, IRCCS Istituto Nazionale Tumori "Fondazione G. Pascale", 80131 Napoli, Italy.
| | - Andrea Polo
- Experimental Pharmacology Unit, IRCCS Istituto Nazionale Tumori "Fondazione G. Pascale", 80131 Napoli, Italy.
| | - Sabrina Bimonte
- Division of Anesthesia and Pain Medicine, IRCCS Istituto Nazionale Tumori "Fondazione G. Pascale", 80131 Napoli, Italy.
| | - Mario Capunzo
- Department of Medicine Surgery and Dentistry, University of Salerno, Baronissi, 84081 Salerno, Italy.
| | - Alfonso Amore
- Abdominal Surgical Oncology and Hepatobiliary Unit, IRCCS Istituto Nazionale Tumori "Fondazione G. Pascale", 80131 Napoli, Italy.
| | - Giovanni D'Arena
- Department of Hematology and Stem Cell Transplantation Unit, IRCCS, Cancer Referral Center of Basilicata, 85028 Rionero in Vulture, Italy.
| | - Pellegrino Cerino
- Istituto Zooprofilattico Sperimentale del Mezzogiorno (IZSM), 80055 Portici, Napoli, Italy.
| | - Alfredo Budillon
- Experimental Pharmacology Unit, IRCCS Istituto Nazionale Tumori "Fondazione G. Pascale", 80131 Napoli, Italy.
| | - Gerardo Botti
- Pathology Unit, IRCCS Istituto Nazionale Tumori "Fondazione G. Pascale", 80131 Napoli, Italy.
| | - Susan Costantini
- Experimental Pharmacology Unit, IRCCS Istituto Nazionale Tumori "Fondazione G. Pascale", 80131 Napoli, Italy.
| | - Maurizio Montella
- Epidemiology Unit, IRCCS Istituto Nazionale Tumori "Fondazione G. Pascale", 80131 Napoli, Italy.
| |
Collapse
|
20
|
Cardelli M. The epigenetic alterations of endogenous retroelements in aging. Mech Ageing Dev 2018; 174:30-46. [PMID: 29458070 DOI: 10.1016/j.mad.2018.02.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 02/05/2018] [Accepted: 02/08/2018] [Indexed: 02/06/2023]
Abstract
Endogenous retroelements, transposons that mobilize through RNA intermediates, include some of the most abundant repetitive sequences of the human genome, such as Alu and LINE-1 sequences, and human endogenous retroviruses. Recent discoveries demonstrate that these mobile genetic elements not only act as intragenomic parasites, but also exert regulatory roles in living cells. The risk of genomic instability represented by endogenous retroelements is normally counteracted by a series of epigenetic control mechanisms which include, among the most important, CpG DNA methylation. Indeed, most of the genomic CpG sites subjected to DNA methylation in the nuclear DNA are carried by these repetitive elements. As other parts of the genome, endogenous retroelements and other transposable elements are subjected to deep epigenetic alterations during aging, repeatedly observed in the context of organismal and cellular senescence, in human and other species. This review summarizes the current status of knowledge about the epigenetic alterations occurring in this large, non-genic portion of the genome in aging and age-related conditions, with a focus on the causes and the possible functional consequences of these alterations.
Collapse
Affiliation(s)
- Maurizio Cardelli
- Advanced Technology Center for Aging Research, Scientific Technological Area, Italian National Research Center on Aging (INRCA), via Birarelli 8, 60121 Ancona, Italy.
| |
Collapse
|
21
|
Platt RN, Vandewege MW, Ray DA. Mammalian transposable elements and their impacts on genome evolution. Chromosome Res 2018; 26:25-43. [PMID: 29392473 PMCID: PMC5857283 DOI: 10.1007/s10577-017-9570-z] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 12/12/2017] [Accepted: 12/28/2017] [Indexed: 12/22/2022]
Abstract
Transposable elements (TEs) are genetic elements with the ability to mobilize and replicate themselves in a genome. Mammalian genomes are dominated by TEs, which can reach copy numbers in the hundreds of thousands. As a result, TEs have had significant impacts on mammalian evolution. Here we summarize the current understanding of TE content in mammal genomes and find that, with a few exceptions, most fall within a predictable range of observations. First, one third to one half of the genome is derived from TEs. Second, most mammalian genomes are dominated by LINE and SINE retrotransposons, more limited LTR retrotransposons, and minimal DNA transposon accumulation. Third, most mammal genome contains at least one family of actively accumulating retrotransposon. Finally, horizontal transfer of TEs among lineages is rare. TE exaptation events are being recognized with increasing frequency. Despite these beneficial aspects of TE content and activity, the majority of TE insertions are neutral or deleterious. To limit the deleterious effects of TE proliferation, the genome has evolved several defense mechanisms that act at the epigenetic, transcriptional, and post-transcriptional levels. The interaction between TEs and these defense mechanisms has led to an evolutionary arms race where TEs are suppressed, evolve to escape suppression, then are suppressed again as the defense mechanisms undergo compensatory change. The result is complex and constantly evolving interactions between TEs and host genomes.
Collapse
Affiliation(s)
- Roy N Platt
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA.
| | | | - David A Ray
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA
| |
Collapse
|
22
|
Ade CM, Derbes RS, Wagstaff BJ, Linker SB, White TB, Deharo D, Belancio VP, Ivics Z, Roy-Engel AM. Evaluating different DNA binding domains to modulate L1 ORF2p-driven site-specific retrotransposition events in human cells. Gene 2017; 642:188-198. [PMID: 29154869 DOI: 10.1016/j.gene.2017.11.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 11/11/2017] [Indexed: 12/28/2022]
Abstract
DNA binding domains (DBDs) have been used with great success to impart targeting capabilities to a variety of proteins creating highly useful genomic tools. We evaluated the ability of five types of DBDs and strategies (AAV Rep proteins, Cre, TAL effectors, zinc finger proteins, and Cas9/gRNA system) to target the L1 ORF2 protein to drive retrotransposition of Alu inserts to specific sequences in the human genome. First, we find that the L1 ORF2 protein tolerates the addition of protein domains both at the amino- and carboxy-terminus. Although in some instances retrotransposition efficiencies slightly diminished, all fusion proteins containing an intact ORF2 were capable of driving retrotransposition. Second, the stability of individual ORF2 fusion proteins varies and difficult to predict. Third, DBDs that require the formation of multimers for target recognition are unlikely to modify targeting of ORF2p-driven insertions. Fourth, the more components needed to assemble into a complex to drive targeted retrotransposition, the less likely the strategy will increase targeted insertions. Fifth, abundance of target sequences present in the genome will likely dictate the effectiveness and efficiency of targeted insertions. Lastly, the cleavage capabilities of Cas9 (or a Cas9 nickase variant) are unable to substitute for the L1 ORF2 endonuclease domain functions, suggestive that the endonuclease domain has alternate functions needed for retrotransposition. From these studies, we conclude that the most critical component for the modification of the human L1 ORF2 protein to drive targeted insertions is the selection of the DBD due to the varying functional requirements and impacts on protein stability.
Collapse
Affiliation(s)
- Catherine M Ade
- Department of Cellular and Molecular Biology, Tulane University, USA
| | - Rebecca S Derbes
- Tulane Cancer Center SL-66, Dept. of Epidemiology, Tulane University Health Sciences Center and LCRC, 1700 Tulane Ave., New Orleans, LA 70112, USA
| | - Bradley J Wagstaff
- Tulane Cancer Center SL-66, Dept. of Epidemiology, Tulane University Health Sciences Center and LCRC, 1700 Tulane Ave., New Orleans, LA 70112, USA
| | - Sara B Linker
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 N Torrey Pines Road, La Jolla, CA 92037-1002, USA
| | - Travis B White
- Sloan Kettering Institute for Cancer Research, New York, NY 10065, USA
| | - Dawn Deharo
- Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70112, USA
| | - Victoria P Belancio
- Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70112, USA
| | - Zoltán Ivics
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, Langen, Germany
| | - Astrid M Roy-Engel
- Tulane Cancer Center SL-66, Dept. of Epidemiology, Tulane University Health Sciences Center and LCRC, 1700 Tulane Ave., New Orleans, LA 70112, USA.
| |
Collapse
|
23
|
Condensin II and GAIT complexes cooperate to restrict LINE-1 retrotransposition in epithelial cells. PLoS Genet 2017; 13:e1007051. [PMID: 29028794 PMCID: PMC5656329 DOI: 10.1371/journal.pgen.1007051] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 10/25/2017] [Accepted: 10/03/2017] [Indexed: 12/15/2022] Open
Abstract
LINE-1 (L1) retrotransposons can mobilize (retrotranspose) within the human genome, and mutagenic de novo L1 insertions can lead to human diseases, including cancers. As a result, cells are actively engaged in preventing L1 retrotransposition. This work reveals that the human Condensin II complex restricts L1 retrotransposition in both non-transformed and transformed cell lines through inhibition of L1 transcription and translation. Condensin II subunits, CAP-D3 and CAP-H2, interact with members of the Gamma-Interferon Activated Inhibitor of Translation (GAIT) complex including the glutamyl-prolyl-tRNA synthetase (EPRS), the ribosomal protein L13a, Glyceraldehyde 3-phosphate dehydrogenase (GAPDH), and NS1 associated protein 1 (NSAP1). GAIT has been shown to inhibit translation of mRNAs encoding inflammatory proteins in myeloid cells by preventing the binding of the translation initiation complex, in response to Interferon gamma (IFN-γ). Excitingly, our data show that Condensin II promotes complexation of GAIT subunits. Furthermore, RNA-Immunoprecipitation experiments in epithelial cells demonstrate that Condensin II and GAIT subunits associate with L1 RNA in a co-dependent manner, independent of IFN-γ. These findings suggest that cooperation between the Condensin II and GAIT complexes may facilitate a novel mechanism of L1 repression, thus contributing to the maintenance of genome stability in somatic cells.
Collapse
|
24
|
Sokolowski M, Chynces M, deHaro D, Christian CM, Belancio VP. Truncated ORF1 proteins can suppress LINE-1 retrotransposition in trans. Nucleic Acids Res 2017; 45:5294-5308. [PMID: 28431148 PMCID: PMC5605252 DOI: 10.1093/nar/gkx211] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 04/12/2017] [Indexed: 01/15/2023] Open
Abstract
Long interspersed element 1 (L1) is an autonomous non-LTR retroelement that is active in mammalian genomes. Although retrotranspositionally incompetent and functional L1 loci are present in the same genomes, it remains unknown whether non-functional L1s have any trans effect on mobilization of active elements. Using bioinformatic analysis, we identified over a thousand of human L1 loci containing at least one stop codon in their ORF1 sequence. RNAseq analysis confirmed that many of these loci are expressed. We demonstrate that introduction of equivalent stop codons in the full-length human L1 sequence leads to the expression of truncated ORF1 proteins. When supplied in trans some truncated human ORF1 proteins suppress human L1 retrotransposition. This effect requires the N-terminus and coiled-coil domain (C-C) as mutations within the ORF1p C-C domain abolish the suppressive effect of truncated proteins on L1 retrotransposition. We demonstrate that the expression levels and length of truncated ORF1 proteins influence their ability to suppress L1 retrotransposition. Taken together these findings suggest that L1 retrotransposition may be influenced by coexpression of defective L1 loci and that these L1 loci may reduce accumulation of de novo L1 integration events.
Collapse
Affiliation(s)
- Mark Sokolowski
- Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70112, USA
| | - May Chynces
- Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70112, USA
| | - Dawn deHaro
- Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70112, USA
| | - Claiborne M Christian
- Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70112, USA
| | - Victoria P Belancio
- Department of Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70112, USA
| |
Collapse
|
25
|
MacLennan M, García-Cañadas M, Reichmann J, Khazina E, Wagner G, Playfoot CJ, Salvador-Palomeque C, Mann AR, Peressini P, Sanchez L, Dobie K, Read D, Hung CC, Eskeland R, Meehan RR, Weichenrieder O, García-Pérez JL, Adams IR. Mobilization of LINE-1 retrotransposons is restricted by Tex19.1 in mouse embryonic stem cells. eLife 2017; 6:e26152. [PMID: 28806172 PMCID: PMC5570191 DOI: 10.7554/elife.26152] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Accepted: 07/11/2017] [Indexed: 12/21/2022] Open
Abstract
Mobilization of retrotransposons to new genomic locations is a significant driver of mammalian genome evolution, but these mutagenic events can also cause genetic disorders. In humans, retrotransposon mobilization is mediated primarily by proteins encoded by LINE-1 (L1) retrotransposons, which mobilize in pluripotent cells early in development. Here we show that TEX19.1, which is induced by developmentally programmed DNA hypomethylation, can directly interact with the L1-encoded protein L1-ORF1p, stimulate its polyubiquitylation and degradation, and restrict L1 mobilization. We also show that TEX19.1 likely acts, at least in part, through promoting the activity of the E3 ubiquitin ligase UBR2 towards L1-ORF1p. Moreover, loss of Tex19.1 increases L1-ORF1p levels and L1 mobilization in pluripotent mouse embryonic stem cells, implying that Tex19.1 prevents de novo retrotransposition in the pluripotent phase of the germline cycle. These data show that post-translational regulation of L1 retrotransposons plays a key role in maintaining trans-generational genome stability in mammals.
Collapse
Affiliation(s)
- Marie MacLennan
- MRC Human Genetics Unit,
MRC Institute of Genetics and Molecular Medicine,
University of Edinburgh, Edinburgh, United
Kingdom
| | - Marta García-Cañadas
- Centro de Genómica e
Investigación Oncológica (GENYO), Pfizer-Universidad de
Granada-Junta de Andalucía, PTS Granada, Granada,
Spain
| | - Judith Reichmann
- MRC Human Genetics Unit,
MRC Institute of Genetics and Molecular Medicine,
University of Edinburgh, Edinburgh, United
Kingdom
| | - Elena Khazina
- Department of
Biochemistry, Max Planck Institute for Developmental
Biology, Tübingen, Germany
| | - Gabriele Wagner
- Department of
Biochemistry, Max Planck Institute for Developmental
Biology, Tübingen, Germany
| | - Christopher J Playfoot
- MRC Human Genetics Unit,
MRC Institute of Genetics and Molecular Medicine,
University of Edinburgh, Edinburgh, United
Kingdom
| | - Carmen Salvador-Palomeque
- Centro de Genómica e
Investigación Oncológica (GENYO), Pfizer-Universidad de
Granada-Junta de Andalucía, PTS Granada, Granada,
Spain
| | - Abigail R Mann
- MRC Human Genetics Unit,
MRC Institute of Genetics and Molecular Medicine,
University of Edinburgh, Edinburgh, United
Kingdom
| | - Paula Peressini
- Centro de Genómica e
Investigación Oncológica (GENYO), Pfizer-Universidad de
Granada-Junta de Andalucía, PTS Granada, Granada,
Spain
| | - Laura Sanchez
- Centro de Genómica e
Investigación Oncológica (GENYO), Pfizer-Universidad de
Granada-Junta de Andalucía, PTS Granada, Granada,
Spain
| | - Karen Dobie
- MRC Human Genetics Unit,
MRC Institute of Genetics and Molecular Medicine,
University of Edinburgh, Edinburgh, United
Kingdom
| | - David Read
- MRC Human Genetics Unit,
MRC Institute of Genetics and Molecular Medicine,
University of Edinburgh, Edinburgh, United
Kingdom
| | - Chao-Chun Hung
- MRC Human Genetics Unit,
MRC Institute of Genetics and Molecular Medicine,
University of Edinburgh, Edinburgh, United
Kingdom
| | - Ragnhild Eskeland
- Department of
Biosciences, University of Oslo,
Oslo,
Norway
- Norwegian Center for
Stem Cell Research, Department of Immunology, Oslo
University Hospital, Oslo, Norway
| | - Richard R Meehan
- MRC Human Genetics Unit,
MRC Institute of Genetics and Molecular Medicine,
University of Edinburgh, Edinburgh, United
Kingdom
| | - Oliver Weichenrieder
- Department of
Biochemistry, Max Planck Institute for Developmental
Biology, Tübingen, Germany
| | - Jose Luis García-Pérez
- MRC Human Genetics Unit,
MRC Institute of Genetics and Molecular Medicine,
University of Edinburgh, Edinburgh, United
Kingdom
- Centro de Genómica e
Investigación Oncológica (GENYO), Pfizer-Universidad de
Granada-Junta de Andalucía, PTS Granada, Granada,
Spain
| | - Ian R Adams
- MRC Human Genetics Unit,
MRC Institute of Genetics and Molecular Medicine,
University of Edinburgh, Edinburgh, United
Kingdom
| |
Collapse
|
26
|
Deininger P, Morales ME, White TB, Baddoo M, Hedges DJ, Servant G, Srivastav S, Smither ME, Concha M, DeHaro DL, Flemington EK, Belancio VP. A comprehensive approach to expression of L1 loci. Nucleic Acids Res 2017; 45:e31. [PMID: 27899577 PMCID: PMC5389711 DOI: 10.1093/nar/gkw1067] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 11/09/2016] [Indexed: 11/14/2022] Open
Abstract
L1 elements represent the only currently active, autonomous retrotransposon in the human genome, and they make major contributions to human genetic instability. The vast majority of the 500 000 L1 elements in the genome are defective, and only a relatively few can contribute to the retrotransposition process. However, there is currently no comprehensive approach to identify the specific loci that are actively transcribed separate from the excess of L1-related sequences that are co-transcribed within genes. We have developed RNA-Seq procedures, as well as a 1200 bp 5΄ RACE product coupled with PACBio sequencing that can identify the specific L1 loci that contribute most of the L1-related RNA reads. At least 99% of L1-related sequences found in RNA do not arise from the L1 promoter, instead representing pieces of L1 incorporated in other cellular RNAs. In any given cell type a relatively few active L1 loci contribute to the 'authentic' L1 transcripts that arise from the L1 promoter, with significantly different loci seen expressed in different tissues.
Collapse
Affiliation(s)
- Prescott Deininger
- Tulane Cancer Center, Tulane University, New Orleans, LA 70112, USA.,Department of Epidemiology, Tulane University, New Orleans, LA 70112, USA
| | - Maria E Morales
- Tulane Cancer Center, Tulane University, New Orleans, LA 70112, USA
| | - Travis B White
- Tulane Cancer Center, Tulane University, New Orleans, LA 70112, USA
| | - Melody Baddoo
- Tulane Cancer Center, Tulane University, New Orleans, LA 70112, USA
| | - Dale J Hedges
- Tulane Cancer Center, Tulane University, New Orleans, LA 70112, USA
| | | | - Sudesh Srivastav
- Department of Structural and Cellular Biology, Tulane University, New Orleans, LA 70112, USA
| | | | - Monica Concha
- Tulane Cancer Center, Tulane University, New Orleans, LA 70112, USA.,Department of Biostatistics and Bioinformatics, Tulane University, New Orleans, LA 70112, USA
| | - Dawn L DeHaro
- Tulane Cancer Center, Tulane University, New Orleans, LA 70112, USA.,Department of Pathology, Tulane University, New Orleans, LA 70112, USA
| | - Erik K Flemington
- Tulane Cancer Center, Tulane University, New Orleans, LA 70112, USA.,Department of Biostatistics and Bioinformatics, Tulane University, New Orleans, LA 70112, USA
| | - Victoria P Belancio
- Tulane Cancer Center, Tulane University, New Orleans, LA 70112, USA.,Department of Pathology, Tulane University, New Orleans, LA 70112, USA
| |
Collapse
|
27
|
Reiter RJ, Rosales-Corral SA, Tan DX, Acuna-Castroviejo D, Qin L, Yang SF, Xu K. Melatonin, a Full Service Anti-Cancer Agent: Inhibition of Initiation, Progression and Metastasis. Int J Mol Sci 2017; 18:E843. [PMID: 28420185 PMCID: PMC5412427 DOI: 10.3390/ijms18040843] [Citation(s) in RCA: 308] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/05/2017] [Accepted: 04/06/2017] [Indexed: 12/21/2022] Open
Abstract
There is highly credible evidence that melatonin mitigates cancer at the initiation, progression and metastasis phases. In many cases, the molecular mechanisms underpinning these inhibitory actions have been proposed. What is rather perplexing, however, is the large number of processes by which melatonin reportedly restrains cancer development and growth. These diverse actions suggest that what is being observed are merely epiphenomena of an underlying more fundamental action of melatonin that remains to be disclosed. Some of the arresting actions of melatonin on cancer are clearly membrane receptor-mediated while others are membrane receptor-independent and involve direct intracellular actions of this ubiquitously-distributed molecule. While the emphasis of melatonin/cancer research has been on the role of the indoleamine in restraining breast cancer, this is changing quickly with many cancer types having been shown to be susceptible to inhibition by melatonin. There are several facets of this research which could have immediate applications at the clinical level. Many studies have shown that melatonin's co-administration improves the sensitivity of cancers to inhibition by conventional drugs. Even more important are the findings that melatonin renders cancers previously totally resistant to treatment sensitive to these same therapies. Melatonin also inhibits molecular processes associated with metastasis by limiting the entrance of cancer cells into the vascular system and preventing them from establishing secondary growths at distant sites. This is of particular importance since cancer metastasis often significantly contributes to death of the patient. Another area that deserves additional consideration is related to the capacity of melatonin in reducing the toxic consequences of anti-cancer drugs while increasing their efficacy. Although this information has been available for more than a decade, it has not been adequately exploited at the clinical level. Even if the only beneficial actions of melatonin in cancer patients are its ability to attenuate acute and long-term drug toxicity, melatonin should be used to improve the physical wellbeing of the patients. The experimental findings, however, suggest that the advantages of using melatonin as a co-treatment with conventional cancer therapies would far exceed improvements in the wellbeing of the patients.
Collapse
Affiliation(s)
- Russel J Reiter
- Department of Cell Systems and Anatomy, UT Health, San Antonio, TX 78229, USA.
| | - Sergio A Rosales-Corral
- Centro de Investigacion Biomedica de Occidente, Del Instituto Mexicano del Seguro Social, Guadalajara 44340, Mexico.
| | - Dun-Xian Tan
- Department of Cell Systems and Anatomy, UT Health, San Antonio, TX 78229, USA.
| | | | - Lilan Qin
- Department of Cell Systems and Anatomy, UT Health, San Antonio, TX 78229, USA.
| | - Shun-Fa Yang
- Institute of Medicine, Chung Shan, Medical University, Taichung 40201, Taiwan.
| | - Kexin Xu
- Department of Molecular Medicine, UT Health, San Antonio, TX 78229, USA.
| |
Collapse
|
28
|
Shukla M, Govitrapong P, Boontem P, Reiter RJ, Satayavivad J. Mechanisms of Melatonin in Alleviating Alzheimer's Disease. Curr Neuropharmacol 2017; 15:1010-1031. [PMID: 28294066 PMCID: PMC5652010 DOI: 10.2174/1570159x15666170313123454] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 02/10/2017] [Accepted: 03/09/2017] [Indexed: 02/07/2023] Open
Abstract
Alzheimer's disease (AD) is a chronic, progressive and prevalent neurodegenerative disease characterized by the loss of higher cognitive functions and an associated loss of memory. The thus far "incurable" stigma for AD prevails because of variations in the success rates of different treatment protocols in animal and human studies. Among the classical hypotheses explaining AD pathogenesis, the amyloid hypothesis is currently being targeted for drug development. The underlying concept is to prevent the formation of these neurotoxic peptides which play a central role in AD pathology and trigger a multispectral cascade of neurodegenerative processes post-aggregation. This could possibly be achieved by pharmacological inhibition of β- or γ-secretase or stimulating the nonamyloidogenic α-secretase. Melatonin the pineal hormone is a multifunctioning indoleamine. Production of this amphiphilic molecule diminishes with advancing age and this decrease runs parallel with the progression of AD which itself explains the potential benefits of melatonin in line of development and devastating consequences of the disease progression. Our recent studies have revealed a novel mechanism by which melatonin stimulates the nonamyloidogenic processing and inhibits the amyloidogenic processing of β-amyloid precursor protein (βAPP) by stimulating α -secretases and consequently down regulating both β- and γ-secretases at the transcriptional level. In this review, we discuss and evaluate the neuroprotective functions of melatonin in AD pathogenesis, including its role in the classical hypotheses in cellular and animal models and clinical interventions in AD patients, and suggest that with early detection, melatonin treatment is qualified to be an anti-AD therapy.
Collapse
Affiliation(s)
- Mayuri Shukla
- Chulabhorn Graduate Institute, Chulabhorn Royal Academy, 54 Kamphaeng Phet 6 Road, Lak Si, Bangkok10210, Thailand
| | - Piyarat Govitrapong
- Chulabhorn Graduate Institute, Chulabhorn Royal Academy, 54 Kamphaeng Phet 6 Road, Lak Si, Bangkok10210, Thailand
- Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakornpathom 73170, Thailand
| | - Parichart Boontem
- Chulabhorn Graduate Institute, Chulabhorn Royal Academy, 54 Kamphaeng Phet 6 Road, Lak Si, Bangkok10210, Thailand
| | - Russel J. Reiter
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Jutamaad Satayavivad
- Chulabhorn Research Institute and Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok10210, Thailand
| |
Collapse
|
29
|
Abstract
Retrotransposons have generated about 40 % of the human genome. This review examines the strategies the cell has evolved to coexist with these genomic "parasites", focussing on the non-long terminal repeat retrotransposons of humans and mice. Some of the restriction factors for retrotransposition, including the APOBECs, MOV10, RNASEL, SAMHD1, TREX1, and ZAP, also limit replication of retroviruses, including HIV, and are part of the intrinsic immune system of the cell. Many of these proteins act in the cytoplasm to degrade retroelement RNA or inhibit its translation. Some factors act in the nucleus and involve DNA repair enzymes or epigenetic processes of DNA methylation and histone modification. RISC and piRNA pathway proteins protect the germline. Retrotransposon control is relaxed in some cell types, such as neurons in the brain, stem cells, and in certain types of disease and cancer, with implications for human health and disease. This review also considers potential pitfalls in interpreting retrotransposon-related data, as well as issues to consider for future research.
Collapse
Affiliation(s)
- John L. Goodier
- McKusick-Nathans Institute for Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD USA 212051
| |
Collapse
|
30
|
Ardeljan D, Taylor MS, Burns KH, Boeke JD, Espey MG, Woodhouse EC, Howcroft TK. Meeting Report: The Role of the Mobilome in Cancer. Cancer Res 2016; 76:4316-9. [PMID: 27527733 DOI: 10.1158/0008-5472.can-15-3421] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 04/13/2016] [Indexed: 11/16/2022]
Abstract
Approximately half of the human genome consists of repetitive sequence attributed to the activities of mobile DNAs, including DNA transposons, RNA transposons, and endogenous retroviruses. Of these, only long interspersed elements (LINE-1 or L1) and sequences copied by LINE-1 remain mobile in our species today. Although cells restrict L1 activity by both transcriptional and posttranscriptional mechanisms, L1 derepression occurs in developmental and pathologic contexts, including many types of cancers. However, we have limited knowledge of the extent and consequences of L1 expression in premalignancies and cancer. Participants in this NIH strategic workshop considered key questions to enhance our understanding of mechanisms and roles the mobilome may play in cancer biology. Cancer Res; 76(15); 4316-9. ©2016 AACR.
Collapse
Affiliation(s)
- Daniel Ardeljan
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland. Medical Scientist Training Program, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Martin S Taylor
- Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts
| | - Kathleen H Burns
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland. Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jef D Boeke
- Institute for Systems Genetics, New York University Langone Medical Center, New York, New York
| | | | | | | |
Collapse
|
31
|
Abstract
The identification of somatic mosaicism in the brain lends a new perspective to our understanding of the role of gene and environment interactions in psychiatric disease risk. Somatic mutations, such as retrotransposon insertions, that are precipitated by modern environmental factors may alter neuronal function and neurological traits, increasing the societal prevalence of mental disorders.
Collapse
Affiliation(s)
- Tracy A Bedrosian
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Sara Linker
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Fred H Gage
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA, 92037, USA.
| |
Collapse
|
32
|
Kines KJ, Sokolowski M, deHaro DL, Christian CM, Baddoo M, Smither ME, Belancio VP. The endonuclease domain of the LINE-1 ORF2 protein can tolerate multiple mutations. Mob DNA 2016; 7:8. [PMID: 27099633 PMCID: PMC4837594 DOI: 10.1186/s13100-016-0064-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 04/07/2016] [Indexed: 11/26/2022] Open
Abstract
Background Approximately 17 % of the human genome is comprised of the Long INterspersed Element-1 (LINE-1 or L1) retrotransposon, the only currently active autonomous family of retroelements. Though L1 elements have helped to shape mammalian genome evolution over millions of years, L1 activity can also be mutagenic and result in human disease. L1 expression has the potential to contribute to genomic instability via retrotransposition and DNA double-strand breaks (DSBs). Additionally, L1 is responsible for structural genomic variations induced by other transposable elements such as Alu and SVA, which rely on the L1 ORF2 protein for their propagation. Most of the genomic damage associated with L1 activity originates with the endonuclease domain of the ORF2 protein, which nicks the DNA in preparation for target-primed reverse transcription. Results Bioinformatic analysis of full-length L1 loci residing in the human genome identified numerous mutations in the amino acid sequence of the ORF2 endonuclease domain. Some of these mutations were found in residues which were predicted to be phosphorylation sites for cellular kinases. We mutated several of these putative phosphorylation sites in the ORF2 endonuclease domain and investigated the effect of these mutations on the function of the full-length ORF2 protein and the endonuclease domain (ENp) alone. Most of the single and multiple point mutations that were tested did not significantly impact expression of the full-length ORF2p, or alter its ability to drive Alu retrotransposition. Similarly, most of those same mutations did not significantly alter expression of ENp, or impair its ability to induce DNA damage and cause toxicity. Conclusions Overall, our data demonstrate that the full-length ORF2p or the ENp alone can tolerate several specific single and multiple point mutations in the endonuclease domain without significant impairment of their ability to support Alu mobilization or induce DNA damage, respectively. Electronic supplementary material The online version of this article (doi:10.1186/s13100-016-0064-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Kristine J Kines
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center and Tulane Center for Aging, New Orleans, LA 70112 USA
| | - Mark Sokolowski
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center and Tulane Center for Aging, New Orleans, LA 70112 USA
| | - Dawn L deHaro
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center and Tulane Center for Aging, New Orleans, LA 70112 USA
| | - Claiborne M Christian
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center and Tulane Center for Aging, New Orleans, LA 70112 USA
| | - Melody Baddoo
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center and Tulane Center for Aging, New Orleans, LA 70112 USA
| | - Madison E Smither
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center and Tulane Center for Aging, New Orleans, LA 70112 USA
| | - Victoria P Belancio
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center and Tulane Center for Aging, New Orleans, LA 70112 USA
| |
Collapse
|
33
|
Christian CM, deHaro D, Kines KJ, Sokolowski M, Belancio VP. Identification of L1 ORF2p sequence important to retrotransposition using Bipartile Alu retrotransposition (BAR). Nucleic Acids Res 2016; 44:4818-34. [PMID: 27095191 PMCID: PMC4889948 DOI: 10.1093/nar/gkw277] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 04/06/2016] [Indexed: 01/14/2023] Open
Abstract
Long Interspersed Element 1 (LINE-1 or L1) is capable of causing genomic instability through the activity of the L1 ORF2 protein (ORF2p). This protein contains endonuclease (EN) and reverse transcriptase (RT) domains that are necessary for the retrotransposition of L1 and the Short Interspersed Element (SINE) Alu. The functional importance of approximately 50% of the ORF2p molecule remains unknown, but some of these sequences could play a role in retrotransposition, or be necessary for the enzymatic activities of the EN and/or RT domains. Conventional approaches using the full-length, contiguous ORF2p make it difficult to study the involvement of these unannotated sequences in the function of L1 ORF2p. Our lab has developed a Bipartile Alu Retrotransposition (BAR) assay that relies on separate truncated ORF2p fragments: an EN-containing and an RT-containing fragment. We validated the utility of this method for studying the ORF2p function in retrotransposition by assessing the effect of expression levels and previously characterized mutations on BAR. Using BAR, we identified two pairs of amino acids important for retrotransposition, an FF and a WD. The WD appears to play a role in cDNA synthesis by the ORF2p molecule, despite being outside the canonical RT domain.
Collapse
Affiliation(s)
- Claiborne M Christian
- Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70130, USA
| | - Dawn deHaro
- Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70130, USA
| | - Kristine J Kines
- Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70130, USA
| | - Mark Sokolowski
- Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70130, USA
| | - Victoria P Belancio
- Structural and Cellular Biology, Tulane University School of Medicine, Tulane Cancer Center, Tulane Center for Aging, New Orleans, LA 70130, USA
| |
Collapse
|
34
|
Mita P, Boeke JD. How retrotransposons shape genome regulation. Curr Opin Genet Dev 2016; 37:90-100. [PMID: 26855260 DOI: 10.1016/j.gde.2016.01.001] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 12/30/2015] [Accepted: 01/17/2016] [Indexed: 12/30/2022]
Abstract
Retrotransposons are mutagenic units able to move within the genome. Despite many defenses deployed by the host to suppress potentially harmful activities of retrotransposons, these genetic units have found ways to meld with normal cellular functions through processes of exaptation and domestication. The same host mechanisms targeting transposon mobility allow for expansion and rewiring of gene regulatory networks on an evolutionary time scale. Recent works demonstrating retrotransposon activity during development, cell differentiation and neurogenesis shed new light on unexpected activities of transposable elements. Moreover, new technological advances illuminated subtler nuances of the complex relationship between retrotransposons and the host genome, clarifying the role of retroelements in evolution, development and impact on human disease.
Collapse
Affiliation(s)
- Paolo Mita
- Institute for Systems Genetics, Department of Biochemistry & Molecular Pharmacology, NYU Langone Medical Center, 430 East 29 Street, NY, NY 10016, USA.
| | - Jef D Boeke
- Institute for Systems Genetics, Department of Biochemistry & Molecular Pharmacology, NYU Langone Medical Center, 430 East 29 Street, NY, NY 10016, USA
| |
Collapse
|
35
|
Kemp JR, Longworth MS. Crossing the LINE Toward Genomic Instability: LINE-1 Retrotransposition in Cancer. Front Chem 2015; 3:68. [PMID: 26734601 PMCID: PMC4679865 DOI: 10.3389/fchem.2015.00068] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 11/27/2015] [Indexed: 12/17/2022] Open
Abstract
Retrotransposons are repetitive DNA sequences that are positioned throughout the human genome. Retrotransposons are capable of copying themselves and mobilizing new copies to novel genomic locations in a process called retrotransposition. While most retrotransposon sequences in the human genome are incomplete and incapable of mobilization, the LINE-1 retrotransposon, which comprises~17% of the human genome, remains active. The disruption of cellular mechanisms that suppress retrotransposon activity is linked to the generation of aneuploidy, a potential driver of tumor development. When retrotransposons insert into a novel genomic region, they have the potential to disrupt the coding sequence of endogenous genes and alter gene expression, which can lead to deleterious consequences for the organism. Additionally, increased LINE-1 copy numbers provide more chances for recombination events to occur between retrotransposons, which can lead to chromosomal breaks and rearrangements. LINE-1 activity is increased in various cancer cell lines and in patient tissues resected from primary tumors. LINE-1 activity also correlates with increased cancer metastasis. This review aims to give a brief overview of the connections between LINE-1 retrotransposition and the loss of genome stability. We will also discuss the mechanisms that repress retrotransposition in human cells and their links to cancer.
Collapse
Affiliation(s)
- Jacqueline R Kemp
- Department of Cellular and Molecular Medicine, Lerner Research Institute of Cleveland Clinic Cleveland, OH, USA
| | - Michelle S Longworth
- Department of Cellular and Molecular Medicine, Lerner Research Institute of Cleveland Clinic Cleveland, OH, USA
| |
Collapse
|
36
|
Smolensky MH, Sackett-Lundeen LL, Portaluppi F. Nocturnal light pollution and underexposure to daytime sunlight: Complementary mechanisms of circadian disruption and related diseases. Chronobiol Int 2015; 32:1029-48. [PMID: 26374931 DOI: 10.3109/07420528.2015.1072002] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Routine exposure to artificial light at night (ALAN) in work, home, and community settings is linked with increased risk of breast and prostate cancer (BC, PC) in normally sighted women and men, the hypothesized biological rhythm mechanisms being frequent nocturnal melatonin synthesis suppression, circadian time structure (CTS) desynchronization, and sleep/wake cycle disruption with sleep deprivation. ALAN-induced perturbation of the CTS melatonin synchronizer signal is communicated maternally at the very onset of life and after birth via breast or artificial formula feedings. Nighttime use of personal computers, mobile phones, electronic tablets, televisions, and the like--now epidemic in adolescents and adults and highly prevalent in pre-school and school-aged children--is a new source of ALAN. However, ALAN exposure occurs concomitantly with almost complete absence of daytime sunlight, whose blue-violet (446-484 nm λ) spectrum synchronizes the CTS and whose UV-B (290-315 nm λ) spectrum stimulates vitamin D synthesis. Under natural conditions and clear skies, day/night and annual cycles of UV-B irradiation drive corresponding periodicities in vitamin D synthesis and numerous bioprocesses regulated by active metabolites augment and strengthen the biological time structure. Vitamin D insufficiency and deficiency are widespread in children and adults in developed and developing countries as a consequence of inadequate sunlight exposure. Past epidemiologic studies have focused either on exposure to too little daytime UV-B or too much ALAN, respectively, on vitamin D deficiency/insufficiency or melatonin suppression in relation to risk of cancer and other, e.g., psychiatric, hypertensive, cardiac, and vascular, so-called, diseases of civilization. The observed elevated incidence of medical conditions the two are alleged to influence through many complementary bioprocesses of cells, tissues, and organs led us to examine effects of the totality of the artificial light environment in which humans reside today. Never have chronobiologic or epidemiologic investigations comprehensively researched the potentially deleterious consequences of the combination of suppressed vitamin D plus melatonin synthesis due to life in today's man-made artificial light environment, which in our opinion is long overdue.
Collapse
Affiliation(s)
- Michael H Smolensky
- a Department of Biomedical Engineering , Cockrell School of Engineering, The University of Texas at Austin , Austin , TX , USA
| | - Linda L Sackett-Lundeen
- b American Association for Clinical Chronobiology and Chronotherapeutics , Roseville , MN , USA , and
| | - Francesco Portaluppi
- c Hypertension Center, S. Anna University Hospital, University of Ferrara , Ferrara , Italy
| |
Collapse
|
37
|
Salavaty A. Carcinogenic effects of circadian disruption: an epigenetic viewpoint. CHINESE JOURNAL OF CANCER 2015; 34:375-83. [PMID: 26253128 PMCID: PMC4593354 DOI: 10.1186/s40880-015-0043-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 06/27/2015] [Indexed: 12/22/2022]
Abstract
Circadian rhythms refer to the endogenous rhythms that are generated to synchronize physiology and behavior with 24-h environmental cues. These rhythms are regulated by both external cues and molecular clock mechanisms in almost all cells. Disruption of circadian rhythms, which is called circadian disruption, affects many biological processes within the body and results in different long-term diseases, including cancer. Circadian regulatory pathways result in rhythmic epigenetic modifications and the formation of circadian epigenomes. Aberrant epigenetic modifications, such as hypermethylation, due to circadian disruption may be involved in the transformation of normal cells into cancer cells. Several studies have indicated an epigenetic basis for the carcinogenic effects of circadian disruption. In this review, I first discuss some of the circadian genes and regulatory proteins. Then, I summarize the current evidence related to the epigenetic modifications that result in circadian disruption. In addition, I explain the carcinogenic effects of circadian disruption and highlight its potential role in different human cancers using an epigenetic viewpoint. Finally, the importance of chronotherapy in cancer treatment is highlighted.
Collapse
Affiliation(s)
- Adrian Salavaty
- Department of Genetics, Faculty of Science, Shahid Chamran University of Ahvaz, 61336-3337, Ahvaz, Iran.
| |
Collapse
|
38
|
Morales ME, Servant G, Ade C, Roy-Enge AM. Altering Genomic Integrity: Heavy Metal Exposure Promotes Transposable Element-Mediated Damage. Biol Trace Elem Res 2015; 166:24-33. [PMID: 25774044 PMCID: PMC4696754 DOI: 10.1007/s12011-015-0298-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 03/03/2015] [Indexed: 12/13/2022]
Abstract
Maintenance of genomic integrity is critical for cellular homeostasis and survival. The active transposable elements (TEs) composed primarily of three mobile element lineages LINE-1, Alu, and SVA comprise approximately 30% of the mass of the human genome. For the past 2 decades, studies have shown that TEs significantly contribute to genetic instability and that TE-caused damages are associated with genetic diseases and cancer. Different environmental exposures, including several heavy metals, influence how TEs interact with its host genome increasing their negative impact. This mini-review provides some basic knowledge on TEs, their contribution to disease, and an overview of the current knowledge on how heavy metals influence TE-mediated damage.
Collapse
Affiliation(s)
- Maria E. Morales
- Department of Epidemiology and Tulane Cancer Center, SL-66, Tulane University Health Sciences Center, 1430 Tulane Ave., New Orleans, LA 70112
| | - Geraldine Servant
- Department of Epidemiology and Tulane Cancer Center, SL-66, Tulane University Health Sciences Center, 1430 Tulane Ave., New Orleans, LA 70112
| | - Catherine Ade
- Department of Cellular and Molecular Biology, Tulane University Health Sciences Center, 1430 Tulane Ave., New Orleans, LA 70112
| | - Astrid M. Roy-Enge
- Department of Epidemiology and Tulane Cancer Center, SL-66, Tulane University Health Sciences Center, 1430 Tulane Ave., New Orleans, LA 70112
- Corresponding author: Astrid M. Roy-Engel, Ph.D., Department of Epidemiology, Tulane Cancer Center, SL66, Tulane University Health Sciences Center, 1430 Tulane Ave., New Orleans, LA 70112. , Phone: (504) 988-6316, Fax: (504) 988-5516
| |
Collapse
|
39
|
Karimi A, Majidzadeh-A K, Madjd Z, Akbari A, Habibi L, Akrami SM. Effect of Copper Sulfate on Expression of Endogenous L1 Retrotransposons in HepG2 Cells (Hepatocellular Carcinoma). Biol Trace Elem Res 2015; 165:131-4. [PMID: 25663478 DOI: 10.1007/s12011-015-0256-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 01/25/2015] [Indexed: 12/26/2022]
Abstract
The long interspersed element-1 (LINE-1 or L1) constitutes approximately 17% of human genome. The expression of these elements is deregulated upon exposure to environmental exposures resulting to genomic instability and cancer promotion. The effect of copper as essential elements in regulation of L1 expression remained to be elucidated. Using non-cytotoxic concentrations of the copper, the expression of endogenous L1 was analyzed by qPCR after 6 days of copper pretreatment in human hepatocellular carcinoma cells (HepG2). The results indicated that the expression of active L1 elements are significantly downregulated at concentrations of 12.5, 25, and 50 μM (p < 0.005). Our data imply that low-level copper exposure may have a protective effect to suppress the induction of L1 activity and decrease incidence of cancer-associated L1 mutagenesis. If this achievement is confirmed by further studies, it can be applied in the long-term goals of cancer prevention.
Collapse
Affiliation(s)
- Abbas Karimi
- Tasnim Biotechnology Research Center (TBRC), Faculty of Medicine, AJA University of Medical Sciences, Etemadzadeh Ave., West Fatemi, Tehran, Iran
| | | | | | | | | | | |
Collapse
|
40
|
Hill SM, Belancio VP, Dauchy RT, Xiang S, Brimer S, Mao L, Hauch A, Lundberg PW, Summers W, Yuan L, Frasch T, Blask DE. Melatonin: an inhibitor of breast cancer. Endocr Relat Cancer 2015; 22:R183-204. [PMID: 25876649 PMCID: PMC4457700 DOI: 10.1530/erc-15-0030] [Citation(s) in RCA: 204] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/14/2015] [Indexed: 12/19/2022]
Abstract
The present review discusses recent work on melatonin-mediated circadian regulation, the metabolic and molecular signaling mechanisms that are involved in human breast cancer growth, and the associated consequences of circadian disruption by exposure to light at night (LEN). The anti-cancer actions of the circadian melatonin signal in human breast cancer cell lines and xenografts heavily involve MT1 receptor-mediated mechanisms. In estrogen receptor alpha (ERα)-positive human breast cancer, melatonin suppresses ERα mRNA expression and ERα transcriptional activity via the MT1 receptor. Melatonin also regulates the transactivation of other members of the nuclear receptor superfamily, estrogen-metabolizing enzymes, and the expression of core clock and clock-related genes. Furthermore, melatonin also suppresses tumor aerobic metabolism (the Warburg effect) and, subsequently, cell-signaling pathways critical to cell proliferation, cell survival, metastasis, and drug resistance. Melatonin demonstrates both cytostatic and cytotoxic activity in breast cancer cells that appears to be cell type-specific. Melatonin also possesses anti-invasive/anti-metastatic actions that involve multiple pathways, including inhibition of p38 MAPK and repression of epithelial-mesenchymal transition (EMT). Studies have demonstrated that melatonin promotes genomic stability by inhibiting the expression of LINE-1 retrotransposons. Finally, research in animal and human models has indicated that LEN-induced disruption of the circadian nocturnal melatonin signal promotes the growth, metabolism, and signaling of human breast cancer and drives breast tumors to endocrine and chemotherapeutic resistance. These data provide the strongest understanding and support of the mechanisms that underpin the epidemiologic demonstration of elevated breast cancer risk in night-shift workers and other individuals who are increasingly exposed to LEN.
Collapse
Affiliation(s)
- Steven M Hill
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Victoria P Belancio
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Robert T Dauchy
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Shulin Xiang
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Samantha Brimer
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Lulu Mao
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Adam Hauch
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Peter W Lundberg
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Whitney Summers
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Lin Yuan
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Tripp Frasch
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - David E Blask
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| |
Collapse
|
41
|
Hill SM, Belancio VP, Dauchy RT, Xiang S, Brimer S, Mao L, Hauch A, Lundberg PW, Summers W, Yuan L, Frasch T, Blask DE. Melatonin: an inhibitor of breast cancer. Endocr Relat Cancer 2015. [PMID: 25876649 DOI: 10.1530/er-c-15-0030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/23/2023]
Abstract
The present review discusses recent work on melatonin-mediated circadian regulation, the metabolic and molecular signaling mechanisms that are involved in human breast cancer growth, and the associated consequences of circadian disruption by exposure to light at night (LEN). The anti-cancer actions of the circadian melatonin signal in human breast cancer cell lines and xenografts heavily involve MT1 receptor-mediated mechanisms. In estrogen receptor alpha (ERα)-positive human breast cancer, melatonin suppresses ERα mRNA expression and ERα transcriptional activity via the MT1 receptor. Melatonin also regulates the transactivation of other members of the nuclear receptor superfamily, estrogen-metabolizing enzymes, and the expression of core clock and clock-related genes. Furthermore, melatonin also suppresses tumor aerobic metabolism (the Warburg effect) and, subsequently, cell-signaling pathways critical to cell proliferation, cell survival, metastasis, and drug resistance. Melatonin demonstrates both cytostatic and cytotoxic activity in breast cancer cells that appears to be cell type-specific. Melatonin also possesses anti-invasive/anti-metastatic actions that involve multiple pathways, including inhibition of p38 MAPK and repression of epithelial-mesenchymal transition (EMT). Studies have demonstrated that melatonin promotes genomic stability by inhibiting the expression of LINE-1 retrotransposons. Finally, research in animal and human models has indicated that LEN-induced disruption of the circadian nocturnal melatonin signal promotes the growth, metabolism, and signaling of human breast cancer and drives breast tumors to endocrine and chemotherapeutic resistance. These data provide the strongest understanding and support of the mechanisms that underpin the epidemiologic demonstration of elevated breast cancer risk in night-shift workers and other individuals who are increasingly exposed to LEN.
Collapse
Affiliation(s)
- Steven M Hill
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Victoria P Belancio
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Robert T Dauchy
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Shulin Xiang
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Samantha Brimer
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Lulu Mao
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Adam Hauch
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Peter W Lundberg
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Whitney Summers
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Lin Yuan
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - Tripp Frasch
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| | - David E Blask
- Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA Department of Structural and Cellular BiologyTulane University School of Medicine, 1430 Tulane Avenue, SL-49, New Orleans, Louisiana 70112, USADepartment of SurgeryTulane Cancer Center and Louisiana Cancer Research ConsortiumCircadian Cancer Biology GroupTulane Center for Circadian BiologyTulane University School of Medicine, New Orleans, Louisiana 70112, USA
| |
Collapse
|
42
|
Moldovan JB, Moran JV. The Zinc-Finger Antiviral Protein ZAP Inhibits LINE and Alu Retrotransposition. PLoS Genet 2015; 11:e1005121. [PMID: 25951186 PMCID: PMC4423928 DOI: 10.1371/journal.pgen.1005121] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 03/03/2015] [Indexed: 11/30/2022] Open
Abstract
Long INterspersed Element-1 (LINE-1 or L1) is the only active autonomous retrotransposon in the human genome. To investigate the interplay between the L1 retrotransposition machinery and the host cell, we used co-immunoprecipitation in conjunction with liquid chromatography and tandem mass spectrometry to identify cellular proteins that interact with the L1 first open reading frame-encoded protein, ORF1p. We identified 39 ORF1p-interacting candidate proteins including the zinc-finger antiviral protein (ZAP or ZC3HAV1). Here we show that the interaction between ZAP and ORF1p requires RNA and that ZAP overexpression in HeLa cells inhibits the retrotransposition of engineered human L1 and Alu elements, an engineered mouse L1, and an engineered zebrafish LINE-2 element. Consistently, siRNA-mediated depletion of endogenous ZAP in HeLa cells led to a ~2-fold increase in human L1 retrotransposition. Fluorescence microscopy in cultured human cells demonstrated that ZAP co-localizes with L1 RNA, ORF1p, and stress granule associated proteins in cytoplasmic foci. Finally, molecular genetic and biochemical analyses indicate that ZAP reduces the accumulation of full-length L1 RNA and the L1-encoded proteins, yielding mechanistic insight about how ZAP may inhibit L1 retrotransposition. Together, these data suggest that ZAP inhibits the retrotransposition of LINE and Alu elements. Long INterspersed Element-1 (LINE-1 or L1) is the only active autonomous retrotransposon in the human genome. L1s comprise ~17% of human DNA and it is estimated that an average human genome has ~80–100 active L1s. L1 moves throughout the genome via a “copy-and-paste” mechanism known as retrotransposition. L1 retrotransposition is known to cause mutations; thus, it stands to reason that the host cell has evolved mechanisms to protect the cell from unabated retrotransposition. Here, we demonstrate that the zinc-finger antiviral protein (ZAP) inhibits the retrotransposition of human L1 and Alu retrotransposons, as well as related retrotransposons from mice and zebrafish. Biochemical and genetic data suggest that ZAP interacts with L1 RNA. Fluorescent microscopy demonstrates that ZAP associates with L1 in cytoplasmic foci that co-localize with stress granule proteins. Mechanistic analyses suggest that ZAP reduces the expression of full-length L1 RNA and the L1-encoded proteins, thereby providing mechanistic insight for how ZAP may restricts retrotransposition. Importantly, these data suggest that ZAP initially may have evolved to combat endogenous retrotransposons and subsequently was co-opted as a viral restriction factor.
Collapse
Affiliation(s)
- John B. Moldovan
- Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail: (JBM); (JVM)
| | - John V. Moran
- Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, Michigan, United States of America
- Departments of Human Genetics and Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- Howard Hughes Medical Institute, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail: (JBM); (JVM)
| |
Collapse
|
43
|
Belancio VP. LINE-1 activity as molecular basis for genomic instability associated with light exposure at night. Mob Genet Elements 2015; 5:1-5. [PMID: 26442182 DOI: 10.1080/2159256x.2015.1037416] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 03/24/2015] [Accepted: 03/26/2015] [Indexed: 12/29/2022] Open
Abstract
The original hypothesis that exposure to light at night increases risk of breast cancer via suppression of nocturnal melatonin production was proposed over 2 decades ago. In 2007, shift work that involves circadian disruption has been recognized by the World Health Organization as a probable human carcinogen. Our discovery of melatonin-dependent regulation of LINE-1 retrotransposon expression and mobilization is the latest addition to the list of cellular genes and processes that are affected by light exposure at night. This finding establishes an unexpected health relevant connection between this endogenous DNA damaging agent and environmental light exposure. It also offers an appealing hypothesis pertaining to the origin of genomic instability in the genomes of individuals with light at night- or age-associated disruption of melatonin signaling.
Collapse
Affiliation(s)
- Victoria P Belancio
- Department of Structural and Cellular Biology; Tulane Cancer Center; Tulane Cancer for Aging; Tulane Center for Circadian Biology; Tulane University ; New Orleans, LA USA
| |
Collapse
|
44
|
Alonso-González C, González A, Martínez-Campa C, Gómez-Arozamena J, Cos S. Melatonin sensitizes human breast cancer cells to ionizing radiation by downregulating proteins involved in double-strand DNA break repair. J Pineal Res 2015; 58:189-97. [PMID: 25623566 DOI: 10.1111/jpi.12205] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 01/06/2015] [Indexed: 11/28/2022]
Abstract
Radiation and adjuvant endocrine therapy are nowadays considered a standard treatment option after surgery in breast cancer. Melatonin exerts oncostatic actions on human breast cancer cells. In the current study, we investigated the effects of a combination of radiotherapy and melatonin on human breast cancer cells. Melatonin (1 mm, 10 μm and 1 nm) significantly inhibited the proliferation of MCF-7 cells. Radiation alone inhibited the MCF-7 cell proliferation in a dose-dependent manner. Pretreatment of breast cancer cells with melatonin 1 wk before radiation led to a significantly greater decrease of MCF-7 cell proliferation compared with radiation alone. Melatonin pretreatment before radiation also decreased G2 -M phase arrest compared with irradiation alone, with a higher percentage of cells in the G0 -G1 phase and a lower percentage of cells in S phase. Radiation alone diminished RAD51 and DNA-protein kinase (PKcs) mRNA expression, two main proteins involved in double-strand DNA break repair. Treatment with melatonin for 7 days before radiation led to a significantly greater decrease in RAD51 and DNA-PKcs mRNA expression compared with radiation alone. Our findings suggest that melatonin pretreatment before radiation sensitizes breast cancer cells to the ionizing effects of radiation by decreasing cell proliferation, inducing cell cycle arrest and downregulating proteins involved in double-strand DNA break repair. These findings may have implications for designing clinical trials using melatonin and radiotherapy.
Collapse
Affiliation(s)
- Carolina Alonso-González
- Department of Physiology and Pharmacology, School of Medicine, University of Cantabria and Instituto de Investigación Valdecilla (IDIVAL), Santander, Spain
| | | | | | | | | |
Collapse
|
45
|
Belancio VP, Blask DE, Deininger P, Hill SM, Jazwinski SM. The aging clock and circadian control of metabolism and genome stability. Front Genet 2015; 5:455. [PMID: 25642238 PMCID: PMC4294216 DOI: 10.3389/fgene.2014.00455] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 12/11/2014] [Indexed: 11/13/2022] Open
Abstract
It is widely accepted that aging is characterized by a gradual decline in the efficiency and accuracy of biological processes, leading to deterioration of physiological functions and development of age-associated diseases. Age-dependent accumulation of genomic instability and development of metabolic syndrome are well-recognized components of the aging phenotype, both of which have been extensively studied. Existing findings strongly support the view that the integrity of the cellular genome and metabolic function can be influenced by light at night (LAN) and associated suppression of circadian melatonin production. While LAN is reported to accelerate aging by promoting age-associated carcinogenesis in several animal models, the specific molecular mechanism(s) of its action are not fully understood. Here, we review literature supporting a connection between LAN-induced central circadian disruption of peripheral circadian rhythms and clock function, LINE-1 retrotransposon-associated genomic instability, metabolic deregulation, and aging. We propose that aging is a progressive decline in the stability, continuity, and synchronization of multi-frequency oscillations in biological processes to a temporally disorganized state. By extension, healthy aging is the ability to maintain the most consistent, stable, and entrainable rhythmicity and coordination of these oscillations, at the molecular, cellular, and systemic levels.
Collapse
Affiliation(s)
- Victoria P Belancio
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane University New Orleans, LA, USA ; Tulane Cancer Center, Tulane Center for Aging, and Tulane Center for Circadian Biology New Orleans, LA, USA
| | - David E Blask
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane University New Orleans, LA, USA ; Tulane Cancer Center, Tulane Center for Aging, and Tulane Center for Circadian Biology New Orleans, LA, USA
| | - Prescott Deininger
- Tulane Cancer Center, Tulane Center for Aging, and Tulane Center for Circadian Biology New Orleans, LA, USA ; Department of Epidemiology, Tulane University New Orleans, LA, USA
| | - Steven M Hill
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane University New Orleans, LA, USA ; Tulane Cancer Center, Tulane Center for Aging, and Tulane Center for Circadian Biology New Orleans, LA, USA
| | - S Michal Jazwinski
- Tulane Cancer Center, Tulane Center for Aging, and Tulane Center for Circadian Biology New Orleans, LA, USA ; Department of Medicine, Tulane University New Orleans, LA, USA
| |
Collapse
|
46
|
Sokolowski M, DeFreece CB, Servant G, Kines KJ, deHaro DL, Belancio VP. Development of a monoclonal antibody specific to the endonuclease domain of the human LINE-1 ORF2 protein. Mob DNA 2014; 5:29. [PMID: 25606060 PMCID: PMC4279459 DOI: 10.1186/s13100-014-0029-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 11/14/2014] [Indexed: 02/06/2023] Open
Abstract
Background LINE-1 (L1) retrotransposons are common occupants of mammalian genomes representing about a fifth of the genetic content. Ongoing L1 retrotransposition in the germ line and somatic tissues has contributed to structural genomic variations and disease-causing mutations in the human genome. L1 mobilization relies on the function of two, self-encoded proteins, ORF1 and ORF2. The ORF2 protein contains two characterized domains: endonuclease and reverse transcriptase. Results Using a bacterially purified endonuclease domain of the human L1 ORF2 protein, we have generated a monoclonal antibody specific to the human ORF2 protein. We determined that the epitope recognized by this monoclonal antibody includes amino acid 205, which is required for the function of the L1 ORF2 protein endonuclease. Using an in vitro L1 cleavage assay, we demonstrate that the monoclonal anti-ORF2 protein antibody partially inhibits L1 endonuclease activity without having any effect on the in vitro activity of the human AP endonuclease. Conclusions Overall, our data demonstrate that this anti-ORF2 protein monoclonal antibody is a useful tool for human L1-related studies and that it provides a rationale for the development of antibody-based inhibitors of L1-induced damage. Electronic supplementary material The online version of this article (doi:10.1186/s13100-014-0029-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Mark Sokolowski
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center, and Tulane Center for Aging, New Orleans, LA 70112 USA
| | - Cecily B DeFreece
- Department of Biology, Xavier University, 1 Drexel Drive, Box 85, New Orleans, LA 70125-7918 USA
| | - Geraldine Servant
- Department of Epidemiology, Tulane School of Public Health, Tulane Cancer Center, New Orleans, LA 70112 USA
| | - Kristine J Kines
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center, and Tulane Center for Aging, New Orleans, LA 70112 USA
| | - Dawn L deHaro
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center, and Tulane Center for Aging, New Orleans, LA 70112 USA
| | - Victoria P Belancio
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center, and Tulane Center for Aging, New Orleans, LA 70112 USA
| |
Collapse
|
47
|
Harb F, Hidalgo MP, Martau B. Lack of exposure to natural light in the workspace is associated with physiological, sleep and depressive symptoms. Chronobiol Int 2014; 32:368-75. [DOI: 10.3109/07420528.2014.982757] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|