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Lu X, Ni P, Suarez-Meade P, Ma Y, Forrest EN, Wang G, Wang Y, Quiñones-Hinojosa A, Gerstein M, Jiang YH. Transcriptional determinism and stochasticity contribute to the complexity of autism-associated SHANK family genes. Cell Rep 2024; 43:114376. [PMID: 38900637 DOI: 10.1016/j.celrep.2024.114376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 05/08/2024] [Accepted: 05/31/2024] [Indexed: 06/22/2024] Open
Abstract
Precision of transcription is critical because transcriptional dysregulation is disease causing. Traditional methods of transcriptional profiling are inadequate to elucidate the full spectrum of the transcriptome, particularly for longer and less abundant mRNAs. SHANK3 is one of the most common autism causative genes. Twenty-four Shank3-mutant animal lines have been developed for autism modeling. However, their preclinical validity has been questioned due to incomplete Shank3 transcript structure. We apply an integrative approach combining cDNA-capture and long-read sequencing to profile the SHANK3 transcriptome in humans and mice. We unexpectedly discover an extremely complex SHANK3 transcriptome. Specific SHANK3 transcripts are altered in Shank3-mutant mice and postmortem brain tissues from individuals with autism spectrum disorder. The enhanced SHANK3 transcriptome significantly improves the detection rate for potential deleterious variants from genomics studies of neuropsychiatric disorders. Our findings suggest that both deterministic and stochastic transcription of the genome is associated with SHANK family genes.
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Affiliation(s)
- Xiaona Lu
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Pengyu Ni
- Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06520, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | | | - Yu Ma
- Department of Neurology, Children's Hospital of Fudan University, Shanghai 201102, China
| | - Emily Niemitz Forrest
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Guilin Wang
- Keck Microarray Shared Resource, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Yi Wang
- Department of Neurology, Children's Hospital of Fudan University, Shanghai 201102, China
| | | | - Mark Gerstein
- Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06520, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA; Department of Computer Science, Yale University, New Haven, CT 06520, USA; Department of Statistics and Data Science, Yale University, New Haven, CT 06520, USA; Department of Biomedical Informatics & Data Science, Yale University, New Haven, CT 06520, USA
| | - Yong-Hui Jiang
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA; Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA; Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA.
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2
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Lu X, Ni P, Suarez-Meade P, Ma Y, Forrest EN, Wang G, Wang Y, Quiñones-Hinojosa A, Gerstein M, Jiang YH. Transcriptional Determinism and Stochasticity Contribute to the Complexity of Autism Associated SHANK Family Genes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.18.585480. [PMID: 38562714 PMCID: PMC10983920 DOI: 10.1101/2024.03.18.585480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Precision of transcription is critical because transcriptional dysregulation is disease causing. Traditional methods of transcriptional profiling are inadequate to elucidate the full spectrum of the transcriptome, particularly for longer and less abundant mRNAs. SHANK3 is one of the most common autism causative genes. Twenty-four Shank3 mutant animal lines have been developed for autism modeling. However, their preclinical validity has been questioned due to incomplete Shank3 transcript structure. We applied an integrative approach combining cDNA-capture and long-read sequencing to profile the SHANK3 transcriptome in human and mice. We unexpectedly discovered an extremely complex SHANK3 transcriptome. Specific SHANK3 transcripts were altered in Shank3 mutant mice and postmortem brains tissues from individuals with ASD. The enhanced SHANK3 transcriptome significantly improved the detection rate for potential deleterious variants from genomics studies of neuropsychiatric disorders. Our findings suggest the stochastic transcription of genome associated with SHANK family genes.
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Affiliation(s)
- Xiaona Lu
- Department of Genetics, Yale University School of Medicine New Haven, CT, 06520 USA
| | - Pengyu Ni
- Biomedical Informatics & Data Science, Yale University School of Medicine New Haven, CT, 06520 USA
| | | | - Yu Ma
- Department of Neurology, Children’s Hospital of Fudan University, Shanghai, 201102 China
| | | | - Guilin Wang
- Yale Center for Genome Analysis, Yale University School of Medicine New Haven, CT, 06520 USA
| | - Yi Wang
- Department of Neurology, Children’s Hospital of Fudan University, Shanghai, 201102 China
| | | | - Mark Gerstein
- Biomedical Informatics & Data Science, Yale University School of Medicine New Haven, CT, 06520 USA
- Yale Center for Genome Analysis, Yale University School of Medicine New Haven, CT, 06520 USA
| | - Yong-hui Jiang
- Department of Genetics, Yale University School of Medicine New Haven, CT, 06520 USA
- Neuroscienc, Yale University School of Medicine New Haven, CT, 06520 USA
- Pediatrics, Yale University School of Medicine New Haven, CT, 06520 USA
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Kurdi M, Baeesa S, Fadul MM, Alkhotani A, Alkhayyat S, Karami MM, Alsinani T, Katib Y, Fathaddin AA, Faizo E, Lary AI, Almansouri M, Maghrabi Y, Alyousef MA, Addass B. The effect of p53 on the activity of NRF2 and NDRG2 genes through apoptotic pathway in IDH-wildtype glioblastoma. Pathol Res Pract 2024; 254:155118. [PMID: 38241776 DOI: 10.1016/j.prp.2024.155118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/05/2024] [Accepted: 01/08/2024] [Indexed: 01/21/2024]
Abstract
BACKGROUND Tumor suppressor (p53) acts to integrate multiple stress signals into diverse antiproliferative responses. Its potential to transactivate or downregulate genes through apoptotic pathway in IDH-wildtype glioblastoma has never been explored. METHODS A group of twenty patients diagnosed with IDH-wildtype glioblastoma, were tested for p53 expression and NDRG2/NRF2 genes activity through protein and gene profiling assays. The connotation between these elements has been explored. RESULTS The mean patients' age was 64-years. All tumors were IDH-wildtype. p53 was expressed in 12 tumors and absent in 8 tumors. The activity of NDRG2 gene was downregulated in all cases. The activity of NRF2 gene was upregulated in 17 tumors and downregulated in 3 tumors. There was a significant statistical difference in PFS among tumors exhibiting different levels of p53 expression and NDRG2 gene activity [p-value= 0.025], in which 12 tumors with downregulated NDRG2 expression and positive p53 expression had earlier tumor recurrence. This statistical difference in PFS was insignificant when we compared p53 expression with NRF2 gene activity [p-value= 0.079]. CONCLUSIONS During cell cycle arrest at G2 phase, p53 expression in IDH-wildtype glioblastoma in elderly individuals, coupled with the downregulation of NDRG2 gene activity, led to an aberrant increase in tumor cell proliferation and accelerated tumor recurrence. However, the influence of p53 on NRF2 gene activity was found to be insignificant.
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Affiliation(s)
- Maher Kurdi
- Department of Pathology, Faculty of Medicine, King Abdulaziz University, Rabigh, Saudi Arabia.
| | - Saleh Baeesa
- Department of Neurosciences, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia
| | - Motaz M Fadul
- Department of Pathology, Faculty of Medicine, King Abdulaziz University, Rabigh, Saudi Arabia
| | - Alaa Alkhotani
- Department of Pathology, College of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Shadi Alkhayyat
- Department of Internal Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mohammed M Karami
- Department of Clinical Physiology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Taghreed Alsinani
- Department of Neurosurgery, King Fahad General Hospital, Jeddah, Saudi Arabia
| | - Yousef Katib
- Department of Radiology, Faculty of Medicine, Taibah University, Medina, Saudi Arabia
| | - Amany A Fathaddin
- Deprtment of Pathology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Eyad Faizo
- Department of Surgery, Faculty of Medicine, University of Tabuk, Tabuk, Saudi Arabia
| | - Ahmed I Lary
- Section of Neurosurgery, Department of Surgery, King Abdulaziz Medical City, Jeddah, Saudi Arabia
| | - Majid Almansouri
- Department of Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Yazid Maghrabi
- Department of Neurosciences, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia
| | - Mohammed A Alyousef
- Department of Surgery, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Bassam Addass
- Department of Surgery, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
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Kratochvilová L, Vojsovič M, Valková N, Šislerová L, El Rashed Z, Inga A, Monti P, Brázda V. The presence of a G-quadruplex prone sequence upstream of a minimal promoter increases transcriptional activity in the yeast Saccharomyces cerevisiae. Biosci Rep 2023; 43:BSR20231348. [PMID: 38112096 PMCID: PMC10730334 DOI: 10.1042/bsr20231348] [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] [Received: 08/08/2023] [Revised: 11/07/2023] [Accepted: 11/21/2023] [Indexed: 12/20/2023] Open
Abstract
Non-canonical secondary structures in DNA are increasingly being revealed as critical players in DNA metabolism, including modulating the accessibility and activity of promoters. These structures comprise the so-called G-quadruplexes (G4s) that are formed from sequences rich in guanine bases. Using a well-defined transcriptional reporter system, we sought to systematically investigate the impact of the presence of G4 structures on transcription in yeast Saccharomyces cerevisiae. To this aim, different G4 prone sequences were modeled to vary the chance of intramolecular G4 formation, analyzed in vitro by Thioflavin T binding test and circular dichroism and then placed at the yeast ADE2 locus on chromosome XV, downstream and adjacent to a P53 response element (RE) and upstream from a minimal CYC1 promoter and Luciferase 1 (LUC1) reporter gene in isogenic strains. While the minimal CYC1 promoter provides basal reporter activity, the P53 RE enables LUC1 transactivation under the control of P53 family proteins expressed under the inducible GAL1 promoter. Thus, the impact of the different G4 prone sequences on both basal and P53 family protein-dependent expression was measured after shifting cells onto galactose containing medium. The results showed that the presence of G4 prone sequences upstream of a yeast minimal promoter increased its basal activity proportionally to their potential to form intramolecular G4 structures; consequently, this feature, when present near the target binding site of P53 family transcription factors, can be exploited to regulate the transcriptional activity of P53, P63 and P73 proteins.
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Affiliation(s)
- Libuše Kratochvilová
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 61200 Brno, Czech Republic
- Department of Food Chemistry and Biotechnology, Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 61200 Brno, Czech Republic
| | - Matúš Vojsovič
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 61200 Brno, Czech Republic
- Department of Food Chemistry and Biotechnology, Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 61200 Brno, Czech Republic
| | - Natália Valková
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 61200 Brno, Czech Republic
| | - Lucie Šislerová
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 61200 Brno, Czech Republic
- Department of Food Chemistry and Biotechnology, Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 61200 Brno, Czech Republic
| | - Zeinab El Rashed
- Gene Expression Regulation SSD, IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Alberto Inga
- Laboratory of Transcriptional Networks, Department of Cellular, Computational and Integrative Biology, CIBIO, University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Paola Monti
- Mutagenesis and Cancer Prevention UO, IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Václav Brázda
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, 61200 Brno, Czech Republic
- Department of Food Chemistry and Biotechnology, Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 61200 Brno, Czech Republic
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Groen K, Steffens Reinhardt L, Bourdon JC, Avery-Kiejda KA. It is not all about the alpha: elevated expression of p53β variants is associated with lower probability of survival in a retrospective melanoma cohort. Cancer Cell Int 2023; 23:228. [PMID: 37794430 PMCID: PMC10548590 DOI: 10.1186/s12935-023-03083-6] [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: 05/30/2023] [Accepted: 09/23/2023] [Indexed: 10/06/2023] Open
Abstract
BACKGROUND Melanoma is the deadliest type of skin cancer and despite improvements in treatment outcomes, melanoma claimed 57,043 lives in 2020. In most malignancies, p53 mutation rates are above 50% and provide prognostic indications. However, in melanoma where less than a quarter of cases harbour a p53 mutation, the significance of the tumour suppressor may be questioned. Instead, p53 isoforms, which modulate p53's canonical function, may be of greater clinical importance. METHODS The expression of p53 isoforms was evaluated in 123 melanoma specimens by immunohistochemistry using p53 isoform-specific antibodies (DO-1, KJC8, KJC40, and KJC133). To determine whether TP53 mutations may be driving p53 isoform expression, TP53 was sequenced in 30 FFPE melanoma samples. RESULTS The C-terminally truncated p53β isoforms (KJC8) were found to be the most highly expressed p53 isoforms compared to all other isoforms. Further, elevated KJC8 staining was found to correlate with reduced probability of melanoma-specific survival, while KJC40 staining (Δ40p53) positively correlated with reduced melanoma thickness. TAp53 isoforms (p53 retaining both transactivation domains, DO-1), were the second highest p53 isoforms expressed across all samples. Elevated DO-1 staining was also associated with worse survival outcomes and more advanced stages of cancer. Given that the isoforms are likely to work in concert, composite isoform profiles were generated. Composite biomarker profiles revealed that elevated TAp53 (DO-1) and p53β (KJC8) expression, accompanied by low Δ40p53 (KJC40) and Δ133p53 (KJC133) expression was associated with the worst survival outcomes. Supporting the lack of predictive biomarker potential of TP53 in melanoma, no clinicopathological or p53 isoform expression associations could be linked to TP53 status. CONCLUSIONS Given the lack of prognostic biomarker potential derived from TP53 status, this study highlights how p53 isoform expression might progress this field and, pending further validation, may provide additional information to treating oncologists that might be factored into treatment decisions.
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Affiliation(s)
- Kira Groen
- School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, The University of Newcastle, Callaghan, NSW, Australia
- Hunter Medical Research Institute, Level 3 West, Lot 1 Kookaburra Circuit, New Lambton Heights, NSW, Australia
| | - Luiza Steffens Reinhardt
- School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, The University of Newcastle, Callaghan, NSW, Australia
- Hunter Medical Research Institute, Level 3 West, Lot 1 Kookaburra Circuit, New Lambton Heights, NSW, Australia
- Cancer Detection & Therapy Research Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia
| | - Jean-Christophe Bourdon
- School of Medicine, Ninewells Hospital and Medical School, The University of Dundee, Dundee, UK
| | - Kelly A Avery-Kiejda
- School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, The University of Newcastle, Callaghan, NSW, Australia.
- Hunter Medical Research Institute, Level 3 West, Lot 1 Kookaburra Circuit, New Lambton Heights, NSW, Australia.
- Cancer Detection & Therapy Research Program, Hunter Medical Research Institute, New Lambton Heights, NSW, Australia.
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McCann JJ, Fleenor DE, Chen J, Lai CH, Bass TE, Kastan MB. Participation of ATM, SMG1, and DDX5 in a DNA Damage-Induced Alternative Splicing Pathway. Radiat Res 2023; 199:406-421. [PMID: 36921295 PMCID: PMC10162594 DOI: 10.1667/rade-22-00219.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/03/2023] [Indexed: 03/17/2023]
Abstract
Altered cellular responses to DNA damage can contribute to cancer development, progression, and therapeutic resistance. Mutations in key DNA damage response factors occur across many cancer types, and the DNA damage-responsive gene, TP53, is frequently mutated in a high percentage of cancers. We recently reported that an alternative splicing pathway induced by DNA damage regulates alternative splicing of TP53 RNA and further modulates cellular stress responses. Through damage-induced inhibition of the SMG1 kinase, TP53 pre-mRNA is alternatively spliced to generate TP53b mRNA and p53b protein is required for optimal induction of cellular senescence after ionizing radiation-induced DNA damage. Herein, we confirmed and extended these observations by demonstrating that the ATM protein kinase is required for repression of SMG1 kinase activity after ionizing radiation. We found that the RNA helicase and splicing factor, DDX5, interacts with SMG1, is required for alternative splicing of TP53 pre-mRNA to TP53b and TP53c mRNAs after DNA damage, and contributes to radiation-induced cellular senescence. Interestingly, the role of SMG1 in alternative splicing of p53 appears to be distinguishable from its role in regulating nonsense-mediated RNA decay. Thus, ATM, SMG1, and DDX5 participate in a DNA damage-induced alternative splicing pathway that regulates TP53 splicing and modulates radiation-induced cellular senescence.
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Affiliation(s)
- Jennifer J. McCann
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina 27710
| | - Donald E. Fleenor
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina 27710
| | - Jing Chen
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina 27710
| | - Chun-Hsiang Lai
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina 27710
| | - Thomas E. Bass
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina 27710
| | - Michael B. Kastan
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina 27710
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Structural Characteristics of the 5′-Terminal Region of Mouse p53 mRNA and Identification of Proteins That Bind to This mRNA Region. Int J Mol Sci 2022; 23:ijms23179709. [PMID: 36077109 PMCID: PMC9456389 DOI: 10.3390/ijms23179709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 08/19/2022] [Accepted: 08/23/2022] [Indexed: 12/15/2022] Open
Abstract
A mouse model has often been used in studies of p53 gene expression. Detailed interpretation of functional studies is, however, hampered by insufficient knowledge of the impact of mouse p53 mRNA’s structure and its interactions with proteins in the translation process. In particular, the 5′-terminal region of mouse p53 mRNA is an important region which takes part in the regulation of the synthesis of p53 protein and its N-truncated isoform Δ41p53. In this work, the spatial folding of the 5′-terminal region of mouse p53 mRNA and its selected sub-fragments was proposed based on the results of the SAXS method and the RNAComposer program. Subsequently, RNA-assisted affinity chromatography was used to identify proteins present in mouse fibroblast cell lysates that are able to bind the RNA oligomer, which corresponds to the 5′-terminal region of mouse p53 mRNA. Possible sites to which the selected, identified proteins can bind were proposed. Interestingly, most of these binding sites coincide with the sites determined as accessible to hybridization of complementary oligonucleotides. Finally, the high binding affinity of hnRNP K and PCBP2 to the 5′-terminal region of mouse p53 mRNA was confirmed and their possible binding sites were proposed.
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8
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NO news: S-(de)nitrosylation of cathepsins and their relationship with cancer. Anal Biochem 2022; 655:114872. [PMID: 36027970 DOI: 10.1016/j.ab.2022.114872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 08/15/2022] [Accepted: 08/18/2022] [Indexed: 11/22/2022]
Abstract
Tumor formation and progression have been much of a study over the last two centuries. Recent studies have seen different developments for the early diagnosis and treatment of the disease; some of which even promise survival of the patient. Cysteine proteases, mainly cathepsins have been unequivocally identified as putative worthy players of redox imbalance that contribute to the premonition and further progression of cancer by interfering in the normal extracellular and intracellular proteolysis and initiating a proteolytic cascade. The present review article focuses on the study of cancer so far, while establishing facts on how future studies focused on the cellular interrelation between nitric oxide (NO) and cancer, can direct their focus on cathepsins. For a tumor cell to thrive and synergize a cancerous environment, different mutations in the proteolytic and signaling pathways and the proto-oncogenes, oncogenes, and the tumor suppressor genes are made possible through cellular biochemistry and some cancer-stimulating environmental factors. The accumulated findings show that S-nitrosylation of cathepsins under the influence of NO-donors can prevent the invasion of cancer and cause cancer cell death by blocking the activity of cathepsins as well as the major denitrosylase systems using a multi-way approach. Faced with a conundrum of how to fill the gap between the dodging of established cancer hallmarks with cathepsin activity and gaining appropriate research/clinical accreditation using our hypothesis, the scope of this review also explores the interplay and crosstalk between S-nitrosylation and S-(de)nitrosylation of this protease and highlights the utility of charging thioredoxin (Trx) reductase inhibitors, low-molecular-weight dithiols, and Trx mimetics using efficient drug delivery system to prevent the denitrosylation or regaining of cathepsin activity in vivo. In foresight, this raises the prospect that drugs or novel compounds that target cathepsins taking all these factors into consideration could be deployed as alternative or even better treatments for cancer, though further research is needed to ascertain the safety, efficiency and effectiveness of this approach.
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Wylie A, Jones AE, Das S, Lu WJ, Abrams JM. Distinct p53 isoforms code for opposing transcriptional outcomes. Dev Cell 2022; 57:1833-1846.e6. [PMID: 35820415 PMCID: PMC9378576 DOI: 10.1016/j.devcel.2022.06.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 02/15/2022] [Accepted: 06/15/2022] [Indexed: 12/19/2022]
Abstract
p53 genes are conserved transcriptional activators that respond to stress. These proteins can also downregulate genes, but the mechanisms are not understood and are generally assumed to be indirect. Here, we investigate synthetic and native cis-regulatory elements in Drosophila to examine opposing features of p53-mediated transcriptional control in vivo. We show that transcriptional repression by p53 operates continuously through canonical DNA binding sites that confer p53-dependent transactivation at earlier developmental stages. p53 transrepression is correlated with local H3K9me3 chromatin marks and occurs without the need for stress or Chk2. In sufficiency tests, two p53 isoforms qualify as transrepressors and a third qualifies as a transcriptional activator. Targeted isoform-specific knockouts dissociate these opposing transcriptional activities, highlighting features that are dispensable for transactivation but critical for repression and for proper germ cell formation. Together, these results demonstrate that certain p53 isoforms function as constitutive tissue-specific repressors, raising important implications for tumor suppression by the human counterpart.
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Affiliation(s)
- Annika Wylie
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Amanda E Jones
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Simanti Das
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Wan-Jin Lu
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - John M Abrams
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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10
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Padariya M, Jooste ML, Hupp T, Fåhraeus R, Vojtesek B, Vollrath F, Kalathiya U, Karakostis K. The Elephant evolved p53 isoforms that escape mdm2-mediated repression and cancer. Mol Biol Evol 2022; 39:6632613. [PMID: 35792674 PMCID: PMC9279639 DOI: 10.1093/molbev/msac149] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The p53 tumor suppressor is a transcription factor with roles in cell development, apoptosis, oncogenesis, aging, and homeostasis in response to stresses and infections. p53 is tightly regulated by the MDM2 E3 ubiquitin ligase. The p53–MDM2 pathway has coevolved, with MDM2 remaining largely conserved, whereas the TP53 gene morphed into various isoforms. Studies on prevertebrate ancestral homologs revealed the transition from an environmentally induced mechanism activating p53 to a tightly regulated system involving cell signaling. The evolution of this mechanism depends on structural changes in the interacting protein motifs. Elephants such as Loxodonta africana constitute ideal models to investigate this coevolution as they are large and long-living as well as having 20 copies of TP53 isoformic sequences expressing a variety of BOX-I MDM2-binding motifs. Collectively, these isoforms would enhance sensitivity to cellular stresses, such as DNA damage, presumably accounting for strong cancer defenses and other adaptations favoring healthy aging. Here we investigate the molecular evolution of the p53–MDM2 system by combining in silico modeling and in vitro assays to explore structural and functional aspects of p53 isoforms retaining the MDM2 interaction, whereas forming distinct pools of cell signaling. The methodology used demonstrates, for the first time that in silico docking simulations can be used to explore functional aspects of elephant p53 isoforms. Our observations elucidate structural and mechanistic aspects of p53 regulation, facilitate understanding of complex cell signaling, and suggest testable hypotheses of p53 evolution referencing Peto’s Paradox.
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Affiliation(s)
- Monikaben Padariya
- International Centre for Cancer Vaccine Science, University of Gdansk , ul. Kładki 24, 80-822 Gdansk , Poland
| | - Mia-Lyn Jooste
- Institute of Genetics and Cancer, University of Edinburgh , Edinburgh EH4 2XR, UK
| | - Ted Hupp
- Institute of Genetics and Cancer, University of Edinburgh , Edinburgh EH4 2XR, UK
| | - Robin Fåhraeus
- International Centre for Cancer Vaccine Science, University of Gdansk , ul. Kładki 24, 80-822 Gdansk , Poland
- Inserm UMRS1131, Institut de Génétique Moléculaire , Université Paris 7, Hôpital St. Louis, F-75010 Paris , France
- Research Centre for Applied Molecular Oncology (RECAMO), Masaryk Memorial Cancer Institute , 65653 Brno , Czech Republic
- Department of Medical Biosciences, Umeå University , 90185 Umeå , Sweden
| | - Borek Vojtesek
- Research Centre for Applied Molecular Oncology (RECAMO), Masaryk Memorial Cancer Institute , 65653 Brno , Czech Republic
| | - Fritz Vollrath
- Department of Zoology, Zoology Research and Administration Building, University of Oxford , Oxford, UK
- Save the Elephants Marula Manor , Marula Lane, Karen P.O. Box 54667. Nairobi 00200. Kenya Office: +254 720 441 178
| | - Umesh Kalathiya
- International Centre for Cancer Vaccine Science, University of Gdansk , ul. Kładki 24, 80-822 Gdansk , Poland
| | - Konstantinos Karakostis
- Inserm UMRS1131, Institut de Génétique Moléculaire , Université Paris 7, Hôpital St. Louis, F-75010 Paris , France
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona , 08193 Bellaterra (Barcelona) , Spain
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11
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Keeping Cell Death Alive: An Introduction into the French Cell Death Research Network. Biomolecules 2022; 12:biom12070901. [PMID: 35883457 PMCID: PMC9313292 DOI: 10.3390/biom12070901] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 06/16/2022] [Accepted: 06/20/2022] [Indexed: 02/01/2023] Open
Abstract
Since the Nobel Prize award more than twenty years ago for discovering the core apoptotic pathway in C. elegans, apoptosis and various other forms of regulated cell death have been thoroughly characterized by researchers around the world. Although many aspects of regulated cell death still remain to be elucidated in specific cell subtypes and disease conditions, many predicted that research into cell death was inexorably reaching a plateau. However, this was not the case since the last decade saw a multitude of cell death modalities being described, while harnessing their therapeutic potential reached clinical use in certain cases. In line with keeping research into cell death alive, francophone researchers from several institutions in France and Belgium established the French Cell Death Research Network (FCDRN). The research conducted by FCDRN is at the leading edge of emerging topics such as non-apoptotic functions of apoptotic effectors, paracrine effects of cell death, novel canonical and non-canonical mechanisms to induce apoptosis in cell death-resistant cancer cells or regulated forms of necrosis and the associated immunogenic response. Collectively, these various lines of research all emerged from the study of apoptosis and in the next few years will increase the mechanistic knowledge into regulated cell death and how to harness it for therapy.
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12
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p53 Isoforms as Cancer Biomarkers and Therapeutic Targets. Cancers (Basel) 2022; 14:cancers14133145. [PMID: 35804915 PMCID: PMC9264937 DOI: 10.3390/cancers14133145] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 06/22/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary The well-known tumor suppressor protein p53 plays important roles in tumor prevention through transcriptional regulation of its target genes. Reactivation of p53 activity has been a potent strategy for cancer treatment. Accumulating evidences indicate that p53 isoforms truncated/modified in the N- or C-terminus can modulate the p53 pathway in a p53-dependent or p53-independent manner. It is thus imperative to characterize the roles of the p53 isoforms in cancer development. This review illustrates how p53 isoforms participate in tumor development and/or suppression. It also summarizes the knowledge about the p53 isoforms as promising cancer biomarkers and therapeutic targets. Abstract This review aims to summarize the implications of the major isoforms of the tumor suppressor protein p53 in aggressive cancer development. The current knowledge of p53 isoforms, their involvement in cell-signaling pathways, and their interactions with other cellular proteins or factors suggests the existence of an intricate molecular network that regulates their oncogenic function. Moreover, existing literature about the involvement of the p53 isoforms in various cancers leads to the proposition of therapeutic solutions by altering the cellular levels of the p53 isoforms. This review thus summarizes how the major p53 isoforms Δ40p53α/β/γ, Δ133p53α/β/γ, and Δ160p53α/β/γ might have clinical relevance in the diagnosis and effective treatments of cancer.
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13
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Effects of cadmium on oxidative stress and cell apoptosis in Drosophila melanogaster larvae. Sci Rep 2022; 12:4762. [PMID: 35307728 PMCID: PMC8934349 DOI: 10.1038/s41598-022-08758-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 03/11/2022] [Indexed: 12/22/2022] Open
Abstract
AbstractWith the increase of human activities, cadmium (Cd) pollution has become a global environmental problem affecting biological metabolism in ecosystem. Cd has a very long half-life in humans and is excreted slowly in organs, which poses a serious threat to human health. In order to better understand the toxicity effects of cadmium, third instar larvae of Drosophila melanogaster (Canton-S strain) were exposed to different concentrations (1.125 mg/kg, 2.25 mg/kg, 4.5 mg/kg, and 9 mg/kg) of cadmium. Trypan blue staining showed that intestinal cell damage of Drosophila larvae increased and the comet assay indicated significantly more DNA damage in larvae exposed to high Cd concentrations. The nitroblue tetrazolium (NBT) experiments proved that content of reactive oxygen species (ROS) increased, which indicated Cd exposure could induce oxidative stress. In addition, the expression of mitochondrial adenine nucleotide transferase coding gene (sesB and Ant2) and apoptosis related genes (Debcl, hid, rpr, p53, Sce and Diap1) changed, which may lead to increased apoptosis. These findings confirmed the toxicity effects on oxidative stress and cell apoptosis in Drosophila larvae after early cadmium exposure, providing insights into understanding the effects of heavy metal stress in animal development.
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14
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Kratz CP, Steinke-Lange V, Spier I, Aretz S, Schröck E, Holinski-Feder E. Overview of the Clinical Features of Li-Fraumeni Syndrome and the Current European ERN GENTURIS Guideline. Geburtshilfe Frauenheilkd 2022; 82:42-49. [PMID: 35027859 PMCID: PMC8747895 DOI: 10.1055/a-1541-7912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/29/2021] [Indexed: 01/18/2023] Open
Abstract
Patients with a tumour-risk syndrome have a significantly increased risk of developing cancer during their lifetime. A positive family history of tumour disease or an unusually early age of onset may be indicative of a tumour risk syndrome. With the diagnosis of a tumour risk syndrome it is possible to recommend a risk-adapted tumour surveillance programme for the patient and (asymptomatic) family members at risk. This facilitates early detection of possible tumours and thus often prevents advanced tumour stages. Li-Fraumeni syndrome is associated with a significantly increased risk of sarcoma and breast cancer in particular, but it is often not diagnosed clinically in those affected. This article reviews the clinical picture, genetic cause and special aspects in the diagnosis and care of patients with Li-Fraumeni syndrome. The initiative resulted from the European reference network GENTURIS, which has set itself the task of improving the identification and care of
patients with tumour risk syndromes. A first step is the recent publication of a European guideline for Li-Fraumeni syndrome, which is summarised here and discussed in the context of existing recommendations.
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Affiliation(s)
- Christian Peter Kratz
- Klinik für Pädiatrische Hämatologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Verena Steinke-Lange
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, München, Germany.,MGZ Medizinisch Genetisches Zentrum, München, Germany
| | - Isabel Spier
- Institut für Humangenetik, Universitätsklinikum Bonn, Bonn, Germany
| | - Stefan Aretz
- Institut für Humangenetik, Universitätsklinikum Bonn, Bonn, Germany
| | - Evelin Schröck
- Institut für Klinische Genetik, Technische Universität Dresden, Dresden, Germany
| | - Elke Holinski-Feder
- Medizinische Klinik und Poliklinik IV, Campus Innenstadt, Klinikum der Universität München, München, Germany.,MGZ Medizinisch Genetisches Zentrum, München, Germany
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15
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Impact of Alternative Splicing Variants on Liver Cancer Biology. Cancers (Basel) 2021; 14:cancers14010018. [PMID: 35008179 PMCID: PMC8750444 DOI: 10.3390/cancers14010018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 12/24/2022] Open
Abstract
Simple Summary Among the top ten deadly solid tumors are the two most frequent liver cancers, hepatocellular carcinoma, and intrahepatic cholangiocarcinoma, whose development and malignancy are favored by multifactorial conditions, which include aberrant maturation of pre-mRNA due to abnormalities in either the machinery involved in the splicing, i.e., the spliceosome and associated factors, or the nucleotide sequences of essential sites for the exon recognition process. As a consequence of cancer-associated aberrant splicing in hepatocytes- and cholangiocytes-derived cancer cells, abnormal proteins are synthesized. They contribute to the dysregulated proliferation and eventually transformation of these cells to phenotypes with enhanced invasiveness, migration, and multidrug resistance, which contributes to the poor prognosis that characterizes these liver cancers. Abstract The two most frequent primary cancers affecting the liver, whose incidence is growing worldwide, are hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA), which are among the five most lethal solid tumors with meager 5-year survival rates. The common difficulty in most cases to reach an early diagnosis, the aggressive invasiveness of both tumors, and the lack of favorable response to pharmacotherapy, either classical chemotherapy or modern targeted therapy, account for the poor outcome of these patients. Alternative splicing (AS) during pre-mRNA maturation results in changes that might affect proteins involved in different aspects of cancer biology, such as cell cycle dysregulation, cytoskeleton disorganization, migration, and adhesion, which favors carcinogenesis, tumor promotion, and progression, allowing cancer cells to escape from pharmacological treatments. Reasons accounting for cancer-associated aberrant splicing include mutations that create or disrupt splicing sites or splicing enhancers or silencers, abnormal expression of splicing factors, and impaired signaling pathways affecting the activity of the splicing machinery. Here we have reviewed the available information regarding the impact of AS on liver carcinogenesis and the development of malignant characteristics of HCC and iCCA, whose understanding is required to develop novel therapeutical approaches aimed at manipulating the phenotype of cancer cells.
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16
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Δ40p53 isoform up-regulates netrin-1/UNC5B expression and potentiates netrin-1 pro-oncogenic activity. Proc Natl Acad Sci U S A 2021; 118:2103319118. [PMID: 34470826 DOI: 10.1073/pnas.2103319118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Netrin-1, a secreted protein recently characterized as a relevant cancer therapeutic target, is the antiapoptotic ligand of the dependence receptors deleted in colorectal carcinoma and members of the UNC5H family. Netrin-1 is overexpressed in several aggressive cancers where it promotes cancer progression by inhibiting cell death induced by its receptors. Interference of its binding to its receptors has been shown, through the development of a monoclonal neutralizing antinetrin-1 antibody (currently in phase II of clinical trial), to actively induce apoptosis and tumor growth inhibition. The transcription factor p53 was shown to positively regulate netrin-1 gene expression. We show here that netrin-1 could be a target gene of the N-terminal p53 isoform Δ40p53, independent of full-length p53 activity. Using stable cell lines, harboring wild-type or null-p53, in which Δ40p53 expression could be finely tuned, we prove that Δ40p53 binds to and activates the netrin-1 promoter. In addition, we show that forcing immortalized human skeletal myoblasts to produce the Δ40p53 isoform, instead of full-length p53, leads to the up-regulation of netrin-1 and its receptor UNC5B and promotes cell survival. Indeed, we demonstrate that netrin-1 interference, in the presence of Δ40p53, triggers apoptosis in cancer and primary cells, leading to tumor growth inhibition in preclinical in vivo models. Finally, we show a positive correlation between netrin-1 and Δ40p53 gene expression in human melanoma and colorectal cancer biopsies. Hence, we propose that inhibition of netrin-1 binding to its receptors should be a promising therapeutic strategy in human tumors expressing high levels of Δ40p53.
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17
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Tsai YY, Su CH, Tarn WY. p53 Activation in Genetic Disorders: Different Routes to the Same Destination. Int J Mol Sci 2021; 22:9307. [PMID: 34502215 PMCID: PMC8430931 DOI: 10.3390/ijms22179307] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 12/18/2022] Open
Abstract
The tumor suppressor p53 is critical for preventing neoplastic transformation and tumor progression. Inappropriate activation of p53, however, has been observed in a number of human inherited disorders that most often affect development of the brain, craniofacial region, limb skeleton, and hematopoietic system. Genes related to these developmental disorders are essentially involved in transcriptional regulation/chromatin remodeling, rRNA metabolism, DNA damage-repair pathways, telomere maintenance, and centrosome biogenesis. Perturbation of these activities or cellular processes may result in p53 accumulation in cell cultures, animal models, and perhaps humans as well. Mouse models of several p53 activation-associated disorders essentially recapitulate human traits, and inactivation of p53 in these models can alleviate disorder-related phenotypes. In the present review, we focus on how dysfunction of the aforementioned biological processes causes developmental defects via excessive p53 activation. Notably, several disease-related genes exert a pleiotropic effect on those cellular processes, which may modulate the magnitude of p53 activation and establish or disrupt regulatory loops. Finally, we discuss potential therapeutic strategies for genetic disorders associated with p53 misactivation.
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18
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Jaafar M, Paraqindes H, Gabut M, Diaz JJ, Marcel V, Durand S. 2'O-Ribose Methylation of Ribosomal RNAs: Natural Diversity in Living Organisms, Biological Processes, and Diseases. Cells 2021; 10:1948. [PMID: 34440717 PMCID: PMC8393311 DOI: 10.3390/cells10081948] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 01/21/2023] Open
Abstract
Recent findings suggest that ribosomes, the translational machineries, can display a distinct composition depending on physio-pathological contexts. Thanks to outstanding technological breakthroughs, many studies have reported that variations of rRNA modifications, and more particularly the most abundant rRNA chemical modification, the rRNA 2'O-ribose methylation (2'Ome), intrinsically occur in many organisms. In the last 5 years, accumulating reports have illustrated that rRNA 2'Ome varies in human cell lines but also in living organisms (yeast, plant, zebrafish, mouse, human) during development and diseases. These rRNA 2'Ome variations occur either within a single cell line, organ, or patient's sample (i.e., intra-variability) or between at least two biological conditions (i.e., inter-variability). Thus, the ribosomes can tolerate the absence of 2'Ome at some specific positions. These observations question whether variations in rRNA 2'Ome could provide ribosomes with particular translational regulatory activities and functional specializations. Here, we compile recent studies supporting the heterogeneity of ribosome composition at rRNA 2'Ome level and provide an overview of the natural diversity in rRNA 2'Ome that has been reported up to now throughout the kingdom of life. Moreover, we discuss the little evidence that suggests that variations of rRNA 2'Ome can effectively impact the ribosome activity and contribute to the etiology of some human diseases.
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Affiliation(s)
| | | | | | | | - Virginie Marcel
- Inserm U1052, CNRS UMR5286, Centre de Recherche en Cancérologie de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard, CEDEX 08, F-69373 Lyon, France; (M.J.); (H.P.); (M.G.); (J.-J.D.)
| | - Sébastien Durand
- Inserm U1052, CNRS UMR5286, Centre de Recherche en Cancérologie de Lyon, Université de Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard, CEDEX 08, F-69373 Lyon, France; (M.J.); (H.P.); (M.G.); (J.-J.D.)
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VCP maintains nuclear size by regulating the DNA damage-associated MDC1-p53-autophagy axis in Drosophila. Nat Commun 2021; 12:4258. [PMID: 34253734 PMCID: PMC8275807 DOI: 10.1038/s41467-021-24556-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 06/24/2021] [Indexed: 12/20/2022] Open
Abstract
The maintenance of constant karyoplasmic ratios suggests that nuclear size has physiological significance. Nuclear size anomalies have been linked to malignant transformation, although the mechanism remains unclear. By expressing dominant-negative TER94 mutants in Drosophila photoreceptors, here we show disruption of VCP (valosin-containing protein, human TER94 ortholog), a ubiquitin-dependent segregase, causes progressive nuclear size increase. Loss of VCP function leads to accumulations of MDC1 (mediator of DNA damage checkpoint protein 1), connecting DNA damage or associated responses to enlarged nuclei. TER94 can interact with MDC1 and decreases MDC1 levels, suggesting that MDC1 is a VCP substrate. Our evidence indicates that MDC1 accumulation stabilizes p53A, leading to TER94K2A-associated nuclear size increase. Together with a previous report that p53A disrupts autophagic flux, we propose that the stabilization of p53A in TER94K2A-expressing cells likely hinders the removal of nuclear content, resulting in aberrant nuclear size increase. Cells maintain a constant cytoplasm to nucleus volume ratio, although the role of DNA damage is not well explored. Here, the authors use Drosophila to connect TER94, the fly homolog of VCP, to disruption of DNA damage repair, leading to ubiquitinated Mu2 protein accumulation and enlarged nuclei.
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20
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Legscha KJ, Antunes Ferreira E, Chamoun A, Lang A, Awwad MHS, Ton GNHQ, Galetzka D, Guezguez B, Hundemer M, Bourdon JC, Munder M, Theobald M, Echchannaoui H. Δ133p53α enhances metabolic and cellular fitness of TCR-engineered T cells and promotes superior antitumor immunity. J Immunother Cancer 2021; 9:jitc-2020-001846. [PMID: 34112738 PMCID: PMC8194333 DOI: 10.1136/jitc-2020-001846] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2021] [Indexed: 12/13/2022] Open
Abstract
Background Tumor microenvironment-associated T cell senescence is a key limiting factor for durable effective cancer immunotherapy. A few studies have demonstrated the critical role of the tumor suppressor TP53-derived p53 isoforms in cellular senescence process of non-immune cells. However, their role in lymphocytes, in particular tumor-antigen (TA) specific T cells remain largely unexplored. Methods Human T cells from peripheral blood were retrovirally engineered to coexpress a TA-specific T cell receptor and the Δ133p53α-isoform, and characterized for their cellular phenotype, metabolic profile and effector functions. Results Phenotypic analysis of Δ133p53α-modified T cells revealed a marked reduction of the T-cell inhibitory molecules (ie, CD160 and TIGIT), a lower frequency of senescent-like CD57+ and CD160+ CD8+ T cell populations, and an increased number of less differentiated CD28+ T cells. Consistently, we demonstrated changes in the cellular metabolic program toward a quiescent T cell state. On a functional level, Δ133p53α-expressing T cells acquired a long-term proliferative capacity, showed superior cytokine secretion and enhanced tumor-specific killing in vitro and in mouse tumor model. Finally, we demonstrated the capacity of Δ133p53α to restore the antitumor response of senescent T cells isolated from multiple myeloma patients. Conclusion This study uncovered a broad effect of Δ133p53α isoform in regulating T lymphocyte function. Enhancing fitness and effector functions of senescent T cells by modulation of p53 isoforms could be exploited for future translational research to improve cancer immunotherapy and immunosenescence-related diseases.
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Affiliation(s)
- Kevin Jan Legscha
- Department of Hematology, Oncology and Pneumology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Edite Antunes Ferreira
- Department of Hematology, Oncology and Pneumology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Antonios Chamoun
- Department of Hematology, Oncology and Pneumology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Alexander Lang
- Department of Hematology, Oncology and Pneumology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany
| | | | | | - Danuta Galetzka
- Department of Radiation Oncology and Radiotherapy, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Borhane Guezguez
- Department of Hematology, Oncology and Pneumology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany.,German Cancer Consortium (DKTK), Partner Site, Mainz, Germany
| | - Michael Hundemer
- Department of Internal Medicine V, University of Heidelberg, Heidelberg, Germany
| | | | - Markus Munder
- Department of Hematology, Oncology and Pneumology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany.,Research Center for Immunotherapy (FZI), University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Matthias Theobald
- Department of Hematology, Oncology and Pneumology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany.,German Cancer Consortium (DKTK), Partner Site, Mainz, Germany.,Research Center for Immunotherapy (FZI), University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Hakim Echchannaoui
- Department of Hematology, Oncology and Pneumology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany .,German Cancer Consortium (DKTK), Partner Site, Mainz, Germany
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21
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p53/p73 Protein Network in Colorectal Cancer and Other Human Malignancies. Cancers (Basel) 2021; 13:cancers13122885. [PMID: 34207603 PMCID: PMC8227208 DOI: 10.3390/cancers13122885] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/02/2021] [Accepted: 06/03/2021] [Indexed: 12/16/2022] Open
Abstract
Simple Summary The p53 family of proteins comprises p53, p63, and p73, which share high structural and functional similarity. The two distinct promoters of each locus, the alternative splicing, and the alternative translation initiation sites enable the generation of numerous isoforms with different protein-interacting domains and distinct activities. The co-expressed p53/p73 isoforms have significant but distinct roles in carcinogenesis. Their activity is frequently impaired in human tumors including colorectal carcinoma due to dysregulated expression and a dominant-negative effect accomplished by some isoforms and p53 mutants. The interactions between isoforms are particularly important to understand the onset of tumor formation, progression, and therapeutic response. The understanding of the p53/p73 network can contribute to the development of new targeted therapies. Abstract The p53 tumor suppressor protein is crucial for cell growth control and the maintenance of genomic stability. Later discovered, p63 and p73 share structural and functional similarity with p53. To understand the p53 pathways more profoundly, all family members should be considered. Each family member possesses two promoters and alternative translation initiation sites, and they undergo alternative splicing, generating multiple isoforms. The resulting isoforms have important roles in carcinogenesis, while their expression is dysregulated in several human tumors including colorectal carcinoma, which makes them potential targets in cancer treatment. Their activities arise, at least in part, from the ability to form tetramers that bind to specific DNA sequences and activate the transcription of target genes. In this review, we summarize the current understanding of the biological activities and regulation of the p53/p73 isoforms, highlighting their role in colorectal tumorigenesis. The analysis of the expression patterns of the p53/p73 isoforms in human cancers provides an important step in the improvement of cancer therapy. Furthermore, the interactions among the p53 family members which could modulate normal functions of the canonical p53 in tumor tissue are described. Lastly, we emphasize the importance of clinical studies to assess the significance of combining the deregulation of different members of the p53 family to define the outcome of the disease.
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22
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Blokhina YP, Frees MA, Nguyen A, Sharifi M, Chu DB, Bispo K, Olaya I, Draper BW, Burgess SM. Rad21l1 cohesin subunit is dispensable for spermatogenesis but not oogenesis in zebrafish. PLoS Genet 2021; 17:e1009127. [PMID: 34138874 PMCID: PMC8291703 DOI: 10.1371/journal.pgen.1009127] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 07/20/2021] [Accepted: 05/04/2021] [Indexed: 01/12/2023] Open
Abstract
During meiosis I, ring-shaped cohesin complexes play important roles in aiding the proper segregation of homologous chromosomes. RAD21L is a meiosis-specific vertebrate cohesin that is required for spermatogenesis in mice but is dispensable for oogenesis in young animals. The role of this cohesin in other vertebrate models has not been explored. Here, we tested if the zebrafish homolog Rad21l1 is required for meiotic chromosome dynamics during spermatogenesis and oogenesis. We found that Rad21l1 localizes to unsynapsed chromosome axes. It is also found between the axes of the mature tripartite synaptonemal complex (SC) in both sexes. We knocked out rad21l1 and found that nearly all rad21l1-/- mutants develop as fertile males, suggesting that the mutation causes a defect in juvenile oogenesis, since insufficient oocyte production triggers female to male sex reversal in zebrafish. Sex reversal was partially suppressed by mutation of the checkpoint gene tp53, suggesting that the rad21l1 mutation activates Tp53-mediated apoptosis or arrest in females. This response, however, is not linked to a defect in repairing Spo11-induced double-strand breaks since deletion of spo11 does not suppress the sex reversal phenotype. Compared to tp53 single mutant controls, rad21l1-/- tp53-/- double mutant females produce poor quality eggs that often die or develop into malformed embryos. Overall, these results indicate that the absence of rad21l1-/- females is due to a checkpoint-mediated response and highlight a role for a meiotic-specific cohesin subunit in oogenesis but not spermatogenesis.
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Affiliation(s)
- Yana P. Blokhina
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
- Integrative Genetics and Genomics Graduate Group, University of California, Davis, California, United States of America
| | - Michelle A. Frees
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
| | - An Nguyen
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
| | - Masuda Sharifi
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
- Biochemistry, Molecular, Cellular, and Developmental Biology Graduate Group, University of California, Davis, California, United States of America
| | - Daniel B. Chu
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
- Integrative Genetics and Genomics Graduate Group, University of California, Davis, California, United States of America
| | - Kristi Bispo
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
| | - Ivan Olaya
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
- Integrative Genetics and Genomics Graduate Group, University of California, Davis, California, United States of America
| | - Bruce W. Draper
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
| | - Sean M. Burgess
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
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p53 Protein Isoform Profiles in AML: Correlation with Distinct Differentiation Stages and Response to Epigenetic Differentiation Therapy. Cells 2021; 10:cells10040833. [PMID: 33917201 PMCID: PMC8068061 DOI: 10.3390/cells10040833] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/30/2021] [Accepted: 04/03/2021] [Indexed: 11/17/2022] Open
Abstract
p53 protein isoform expression has been found to correlate with prognosis and chemotherapy response in acute myeloid leukemia (AML). We aimed to investigate how p53 protein isoforms are modulated during epigenetic differentiation therapy in AML, and if p53 isoform expression could be a potential biomarker for predicting a response to this treatment. p53 full-length (FL), p53β and p53γ protein isoforms were analyzed by 1D and 2D gel immunoblots in AML cell lines, primary AML cells from untreated patients and AML cells from patients before and after treatment with valproic acid (VPA), all-trans retinoic acid (ATRA) and theophylline. Furthermore, global gene expression profiling analysis was performed on samples from the clinical protocol. Correlation analyses were performed between p53 protein isoform expression and in vitro VPA sensitivity and FAB (French–American–British) class in primary AML cells. The results show downregulation of p53β/γ and upregulation of p53FL in AML cell lines treated with VPA, and in some of the patients treated with differentiation therapy. p53FL positively correlated with in vitro VPA sensitivity and the FAB class of AML, while p53β/γ isoforms negatively correlated with the same. Our results indicate that p53 protein isoforms are modulated by and may predict sensitivity to differentiation therapy in AML.
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24
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Zubair M, Wang S, Ali N. Advanced Approaches to Breast Cancer Classification and Diagnosis. Front Pharmacol 2021; 11:632079. [PMID: 33716731 PMCID: PMC7952319 DOI: 10.3389/fphar.2020.632079] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 12/29/2020] [Indexed: 12/15/2022] Open
Abstract
The International Agency for Research on Cancer (IARC) has recently reported a 66% increase in the global number of cancer deaths since 1960. In the US alone, about one in eight women is expected to develop invasive breast cancer(s) (breast cancer) at some point in their lifetime. Traditionally, a BC diagnosis includes mammography, ultrasound, and some high-end molecular bioimaging. Unfortunately, these techniques detect BC at a later stage. So early and advanced molecular diagnostic tools are still in demand. In the past decade, various histological and immuno-molecular studies have demonstrated that BC is highly heterogeneous in nature. Its growth pattern, cytological features, and expression of key biomarkers in BC cells including hormonal receptor markers can be utilized to develop advanced diagnostic and therapeutic tools. A cancer cell's progression to malignancy exhibits various vital biomarkers, many of which are still underrepresented in BC diagnosis and treatment. Advances in genetics have also enabled the development of multigene assays to detect genetic heterogeneity in BC. However, thus far, the FDA has approved only four such biomarkers-cancer antigens (CA); CA 15-3, CA 27-29, Human epidermal growth factor receptor 2 (HER2), and circulating tumor cells (CTC) in assessing BC in body fluids. An adequately structured portable-biosensor with its non-invasive and inexpensive point-of-care analysis can quickly detect such biomarkers without significantly compromising its specificity and selectivity. Such advanced techniques are likely to discriminate between BC and a healthy patient by accurately measuring the cell shape, structure, depth, intracellular and extracellular environment, and lipid membrane compositions. Presently, BC treatments include surgery and systemic chemo- and targeted radiation therapy. A biopsied sample is then subjected to various multigene assays to predict the heterogeneity and recurrence score, thus guiding a specific treatment by providing complete information on the BC subtype involved. Thus far, we have seven prognostic multigene signature tests for BC providing a risk profile that can avoid unnecessary treatments in low-risk patients. Many comparative studies on multigene analysis projected the importance of integrating clinicopathological information with genomic-imprint analysis. Current cohort studies such as MINDACT, TAILORx, Trans-aTTOM, and many more, are likely to provide positive impact on long-term patient outcome. This review offers consolidated information on currently available BC diagnosis and treatment options. It further describes advanced biomarkers for the development of state-of-the-art early screening and diagnostic technologies.
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Affiliation(s)
- M. Zubair
- Department of Biology, University of Arkansas at Little Rock, Little Rock, AR, United States
| | - S. Wang
- Department of Chemistry, University of Arkansas at Little Rock, Little Rock, AR, United States
| | - N. Ali
- Department of Biology, University of Arkansas at Little Rock, Little Rock, AR, United States
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Sharma A, Colonna G. System-Wide Pollution of Biomedical Data: Consequence of the Search for Hub Genes of Hepatocellular Carcinoma Without Spatiotemporal Consideration. Mol Diagn Ther 2021; 25:9-27. [PMID: 33475988 PMCID: PMC7847983 DOI: 10.1007/s40291-020-00505-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2020] [Indexed: 12/17/2022]
Abstract
Biomedical institutions rely on data evaluation and are turning into data factories. Big-data storage centers, supercomputing systems, and increased algorithmic efficiency allow us to analyze the ever-increasing amount of data generated every day in biomedical research centers. In network science, the principal intrinsic problem is how to integrate the data and information from different experiments on genes or proteins. Data curation is an essential process in annotating new functional data to known genes or proteins, undertaken by a biobank curator, which is then reflected in the calculated networks. We provide an example of how protein-protein networks today have space-time limits. The next step is the integration of data and information from different biobanks. Omics data and networks are essential parts of this step but also have flawed protocols and errors. Consider data from patients with cancer: from biopsy procedures to experimental tests, to archiving methods and computational algorithms, these are continuously handled so require critical and continuous "updates" to obtain reproducible, reliable, and correct results. We show, as a second example, how all this distorts studies in cellular hepatocellular carcinoma. It is not unlikely that these flawed data have been polluting biobanks for some time before stringent conditions for the veracity of data were implemented in Big data. Therefore, all this could contribute to errors in future medical decisions.
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Affiliation(s)
- Ankush Sharma
- Department of Biosciences, University of Oslo, Oslo, Norway.
- Department of Informatics, University of Oslo, Oslo, Norway.
- Institute of Cancer Research, Institute of Clinical medicine, University of Oslo, Oslo, Norway.
| | - Giovanni Colonna
- Medical Informatics, AOU-Vanvitelli, Università della Campania, Naples, Italy
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Integrative p53, micro-RNA and Cathepsin Protease Co-Regulatory Expression Networks in Cancer. Cancers (Basel) 2020; 12:cancers12113454. [PMID: 33233599 PMCID: PMC7699684 DOI: 10.3390/cancers12113454] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/05/2020] [Accepted: 11/18/2020] [Indexed: 12/12/2022] Open
Abstract
Simple Summary This article describes an emerging area of significant interest in cancer and cell death and the relationships shared by these through the transcriptional regulation of cathepsin protease genes by micro-RNAs that are connected to p53 activation. While it has been demonstrated that the p53 protein can directly regulate some cathepsin genes and the expression of their upstream regulatory micro-RNAs, very little is known about what input the p53 isoform proteins may have in regulating this relationship. Herein, we draw attention to this important regulatory aspect in the context of describing mechanisms that are being established for the micro-RNA regulation of cathepsin protease genes and their collective use in diagnostic or prognostic assays. Abstract As the direct regulatory role of p53 and some of its isoform proteins are becoming established in modulating gene expression in cancer research, another aspect of this mode of gene regulation that has captured significant interest over the years is the mechanistic interplay between p53 and micro-RNA transcriptional regulation. The input of this into modulating gene expression for some of the cathepsin family members has been viewed as carrying noticeable importance based on their biological effects during normal cellular homeostasis and cancer progression. While this area is still in its infancy in relation to general cathepsin gene regulation, we review the current p53-regulated micro-RNAs that are generating significant interest through their regulation of cathepsin proteases, thereby strengthening the link between activated p53 forms and cathepsin gene regulation. Additionally, we extend our understanding of this developing relationship to how such micro-RNAs are being utilized as diagnostic or prognostic tools and highlight their future uses in conjunction with cathepsin gene expression as potential biomarkers within a clinical setting.
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Tu Q, Gong H, Yuan C, Liu G, Huang J, Li Z, Luo J. Δ133p53/FLp53 Predicts Poor Clinical Outcome in Esophageal Squamous Cell Carcinoma. Cancer Manag Res 2020; 12:7405-7417. [PMID: 32884352 PMCID: PMC7443442 DOI: 10.2147/cmar.s263559] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 07/25/2020] [Indexed: 12/16/2022] Open
Abstract
Background p53 isoform Δ133p53 is directly transactivated by p53 and antagonizes p53 activities in cancer progression. However, its correlation with prognosis and cancer recurrence in esophageal squamous cell carcinoma (ESCC) is still unclear. Patients and Methods Expression of Δ133p53 and Δ133p53/full-length p53 (FLp53) in tissues and serums of 180 ESCC patients was evaluated using qRT-PCR. Patients were divided into high- and low-expression groups according to the cutoff value determined by X-tile 3.6.1 software. Survival analysis was performed by the Kaplan-Meier method. Univariate and multivariate Cox survival analyses were applied to assess the hazard ratios (HRs). Results Tissue Δ133p53 expression and Δ133p53/FLp53 ratio were significantly increased in ESCC tissue compared with adjacent normal tissue. Pre-operative Δ133p53 expression and Δ133p53/FLp53 ratio in tissue or serum samples were positively associated with TNM stage and post-operative recurrence. Kaplan-Meier curve and multivariate cox regression analyses revealed that the tissue and serum Δ133p53/FLp53 ratios (cutoff value: 2.9160) were independent prognostic factors for overall survival (OS) and progression-free survival (PFS) in ESCC patients and showed no statistical difference in receiver-operating characteristic curve (ROC) analysis, while serum Δ133p53 showed no significant prognostic value. More importantly, the serum Δ133p53/FLp53 ratio in ESCC patients was significantly decreased within 72 h post tumor resection and patients with a consistently high serum Δ133p53/FLp53 ratio (≥2.9160) had higher recurrence rates than those with consistently low ratio values. In addition, dynamic detection in each follow-up timepoint showed that serum Δ133p53/FLp53 ratios were higher than 2.9160 upon recurrence, and they even increased prior to radiologic progression. Conclusion The serum Δ133p53/FLp53 ratio can be a novel predictor for survival outcome and may serve as a real-time parameter for monitoring recurrence in ESCC patients after surgery.
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Affiliation(s)
- Qimin Tu
- Department of Cardio-Thoracic Surgery, Central Hospital of Enshi Autonomous Prefecture, Enshi Clinical College of Wuhan University, Enshi, Hubei, People's Republic of China.,Department of Gastrointestinal Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Hongjian Gong
- Clinical Research Center, Wuhan Medical and Health Center for Women and Children, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China.,Department of Rheumatism Immunology, Wuhan Medical and Health Center for Women and Children, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Chunhui Yuan
- Clinical Research Center, Wuhan Medical and Health Center for Women and Children, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Gao Liu
- Department of Gastrointestinal Surgery, Central Hospital of Enshi Autonomous Prefecture, Enshi Clinical College of Wuhan University, Enshi, Hubei, People's Republic of China
| | - Jinqi Huang
- Department of Cardio-Thoracic Surgery, Central Hospital of Enshi Autonomous Prefecture, Enshi Clinical College of Wuhan University, Enshi, Hubei, People's Republic of China
| | - Zhichao Li
- Department of Rheumatism Immunology, Wuhan Medical and Health Center for Women and Children, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Jianfei Luo
- Department of Gastrointestinal Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, People's Republic of China
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Eriksson SE, Ceder S, Bykov VJN, Wiman KG. p53 as a hub in cellular redox regulation and therapeutic target in cancer. J Mol Cell Biol 2020; 11:330-341. [PMID: 30892598 PMCID: PMC6734141 DOI: 10.1093/jmcb/mjz005] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 12/21/2018] [Accepted: 02/11/2019] [Indexed: 12/25/2022] Open
Abstract
The TP53 tumor suppressor gene encodes a DNA-binding transcription factor that regulates multiple cellular processes including cell growth and cell death. The ability of p53 to bind to DNA and activate transcription is tightly regulated by post-translational modifications and is dependent on a reducing cellular environment. Some p53 transcriptional target genes are involved in regulation of the cellular redox homeostasis, e.g. TIGAR and GLS2. A large fraction of human tumors carry TP53 mutations, most commonly missense mutations that lead to single amino acid substitutions in the core domain. Mutant p53 proteins can acquire so called gain-of-function activities and influence the cellular redox balance in various ways, for instance by binding of the Nrf2 transcription factor, a major regulator of cellular redox state. The DNA-binding core domain of p53 has 10 cysteine residues, three of which participate in holding a zinc atom that is critical for p53 structure and function. Several novel compounds that refold and reactivate missense mutant p53 bind to specific p53 cysteine residues. These compounds can also react with other thiols and target components of the cellular redox system, such as glutathione. Dual targeting of mutant p53 and redox homeostasis may allow more efficient treatment of cancer.
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Affiliation(s)
- Sofi E Eriksson
- Karolinska Institutet, Department of Oncology-Pathology, BioClinicum, Stockholm, Sweden
| | - Sophia Ceder
- Karolinska Institutet, Department of Oncology-Pathology, BioClinicum, Stockholm, Sweden
| | - Vladimir J N Bykov
- Karolinska Institutet, Department of Oncology-Pathology, BioClinicum, Stockholm, Sweden
| | - Klas G Wiman
- Karolinska Institutet, Department of Oncology-Pathology, BioClinicum, Stockholm, Sweden
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Good Cop, Bad Cop: Defining the Roles of Δ40p53 in Cancer and Aging. Cancers (Basel) 2020; 12:cancers12061659. [PMID: 32585821 PMCID: PMC7352174 DOI: 10.3390/cancers12061659] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/11/2020] [Accepted: 06/18/2020] [Indexed: 01/10/2023] Open
Abstract
The tumour suppressor p53 is essential for maintaining DNA integrity, and plays a major role in cellular senescence and aging. Understanding the mechanisms that contribute to p53 dysfunction can uncover novel possibilities for improving cancer therapies and diagnosis, as well as cognitive decline associated with aging. In recent years, the complexity of p53 signalling has become increasingly apparent owing to the discovery of the p53 isoforms. These isoforms play important roles in regulating cell growth and turnover in response to different stressors, depending on the cellular context. In this review, we focus on Δ40p53, an N-terminally truncated p53 isoform. Δ40p53 can alter p53 target gene expression in both a positive and negative manner, modulating the biological outcome of p53 activation; it also functions independently of p53. Therefore, proper control of the Δ40p53: p53 ratio is essential for normal cell growth, aging, and responses to cancer therapy. Defining the contexts and the mechanisms by which Δ40p53 behaves as a "good cop or bad cop" is critical if we are to target this isoform therapeutically.
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Oh L, Hainaut P, Blanchet S, Ariffin H. Expression of p53 N-terminal isoforms in B-cell precursor acute lymphoblastic leukemia and its correlation with clinicopathological profiles. BMC Cancer 2020; 20:110. [PMID: 32041553 PMCID: PMC7011217 DOI: 10.1186/s12885-020-6599-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 02/03/2020] [Indexed: 12/13/2022] Open
Abstract
Background TP53 mutations occur in only about 3% of primary and 10–20% of relapse B-cell precursor acute lymphoblastic leukaemia (BCP-ALL). However, alternative mechanisms may contribute to functionally impairing the p53 pathway in the absence of a mutation. Candidate mechanisms include overexpression of p53 mRNA variants encoding either dominant-negative p53 protein isoforms such as Delta40p53 and Delta133p53, or modulatory isoforms such as p53beta, which counteract the effects of Delta133p53 on replicative senescence in T-lymphocytes. Methods We used semi-quantitative reverse-transcriptase PCR (RT-PCR) and Western blot to investigate the expression of full length p53 (TAp53), Delta40p53, Delta133p53 or p53beta in diagnostic marrow from a clinical cohort of 50 BCP-ALL patients without TP53 mutation (29 males and 21 females, age range 2–14 years) and in the bone marrow cells of 4 healthy donors (used as controls). Results Irrespective of isoforms, levels of p53 mRNA were low in controls but were increased by 2 to 20-fold in primary or relapse BCP-ALL. TAp53 was increased in primary BCP-ALL, Delta40p53 was elevated in relapse BCP-ALL, whereas Delta133p53 and p53beta were increased in both. Next, mRNA levels were used as a basis to infer the ratio between protein isoform levels. This inference suggested that, in primary BCP-ALL, p53 was predominantly in active oligomeric conformations dominated by TAp53. In contrast, p53 mostly existed in inactive quaternary conformations containing ≥2 Delta40 or Delta133p53 in relapse BCP-ALL. Western blot analysis of blasts from BCP-ALL showed a complex pattern of N-terminally truncated p53 isoforms, whereas TAp53beta was detected as a major isoform. The hypothesis that p53 is in an active form in primary B-ALL was consistent with elevated level of p53 target genes CDKN1A and MDM2 in primary cases, whereas in relapse BCP-ALL, only CDKN1A was increased as compared to controls. Conclusion Expression of p53 isoforms is deregulated in BCP-ALL in the absence of TP53 mutation, with increased expression of alternative isoforms in relapse BCP-ALL. Variations in isoform expression may contribute to functional deregulation of the p53 pathway in BCP-ALL, specifically contributing to its down-regulation in relapse forms.
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Affiliation(s)
- Lixian Oh
- Department of Paediatrics, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Pierre Hainaut
- Institute of Advanced Biosciences, INSERM 1209 CNRS 5309 University of Grenoble-Alpes, Grenoble, France
| | - Sandrine Blanchet
- Institute of Advanced Biosciences, INSERM 1209 CNRS 5309 University of Grenoble-Alpes, Grenoble, France
| | - Hany Ariffin
- Department of Paediatrics, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
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Gębarowski T, Wiatrak B, Gębczak K, Tylińska B, Gąsiorowski K. Effect of new olivacine derivatives on p53 protein level. Pharmacol Rep 2020; 72:214-224. [PMID: 32016852 DOI: 10.1007/s43440-019-00004-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 09/12/2019] [Accepted: 09/18/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND The p53 protein is a transcription factor for many genes, including genes involved in inhibiting cell proliferation and inducing apoptosis in genotoxically damaged and tumor-transformed cells. In more than 55% of cases of human cancers, loss of the essential function of p53 protein is found. In numerous reports, it has been shown that small molecules (chemical compounds) can restore the suppressor function of the mutant p53 protein in tumor cells. The aim of this study was to evaluate the potential anticancer activity of three newly synthesized olivacine derivatives. METHODS The study was performed using two cell lines-CCRF/CEM (containing the mutant p53 protein) and A549 (containing a non-mutant, wild-type p53 protein). The cells were incubated with olivacine derivatives for 18 h and then assays were carried out: measurement of the amount of p53 and p21 proteins, detection of apoptosis, cell cycle analysis, and rhodamine 123 accumulation assay (evaluation of P-glycoprotein inhibition). Multiple-criteria decision analysis was used to compare the anticancer activity of the tested compounds. RESULTS Each tested compound caused the reconstitution of suppressor activity of the p53 protein in cells with the mutant protein. In addition, one of the compounds showed significant antitumor activity in both wild-type and mutant cells. For all compounds, a stronger effect on the level of the p53 protein was observed than for the reference compound-ellipticine. CONCLUSIONS The observed effects of the tested new olivacine derivatives (pyridocarbazoles) suggest that they are good candidates for new anticancer drugs.
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Affiliation(s)
- Tomasz Gębarowski
- Department of Basic Medical Sciences, Wroclaw Medical University, Borowska 211, 50-556, Wrocław, Poland
| | - Benita Wiatrak
- Department of Basic Medical Sciences, Wroclaw Medical University, Borowska 211, 50-556, Wrocław, Poland.
| | - Katarzyna Gębczak
- Department of Basic Medical Sciences, Wroclaw Medical University, Borowska 211, 50-556, Wrocław, Poland
| | - Beata Tylińska
- Department of Organic Chemistry, Wroclaw Medical University, Wrocław, Poland
| | - Kazimierz Gąsiorowski
- Department of Basic Medical Sciences, Wroclaw Medical University, Borowska 211, 50-556, Wrocław, Poland
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Nibau C, Dadarou D, Kargios N, Mallioura A, Fernandez-Fuentes N, Cavallari N, Doonan JH. A Functional Kinase Is Necessary for Cyclin-Dependent Kinase G1 (CDKG1) to Maintain Fertility at High Ambient Temperature in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2020; 11:586870. [PMID: 33240303 PMCID: PMC7683410 DOI: 10.3389/fpls.2020.586870] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 10/15/2020] [Indexed: 05/15/2023]
Abstract
Maintaining fertility in a fluctuating environment is key to the reproductive success of flowering plants. Meiosis and pollen formation are particularly sensitive to changes in growing conditions, especially temperature. We have previously identified cyclin-dependent kinase G1 (CDKG1) as a master regulator of temperature-dependent meiosis and this may involve the regulation of alternative splicing (AS), including of its own transcript. CDKG1 mRNA can undergo several AS events, potentially producing two protein variants: CDKG1L and CDKG1S, differing in their N-terminal domain which may be involved in co-factor interaction. In leaves, both isoforms have distinct temperature-dependent functions on target mRNA processing, but their role in pollen development is unknown. In the present study, we characterize the role of CDKG1L and CDKG1S in maintaining Arabidopsis fertility. We show that the long (L) form is necessary and sufficient to rescue the fertility defects of the cdkg1-1 mutant, while the short (S) form is unable to rescue fertility. On the other hand, an extra copy of CDKG1L reduces fertility. In addition, mutation of the ATP binding pocket of the kinase indicates that kinase activity is necessary for the function of CDKG1. Kinase mutants of CDKG1L and CDKG1S correctly localize to the cell nucleus and nucleus and cytoplasm, respectively, but are unable to rescue either the fertility or the splicing defects of the cdkg1-1 mutant. Furthermore, we show that there is partial functional overlap between CDKG1 and its paralog CDKG2 that could in part be explained by overlapping gene expression.
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Affiliation(s)
- Candida Nibau
- Institute of Biological Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, United Kingdom
- *Correspondence: Candida Nibau,
| | - Despoina Dadarou
- Institute of Biological Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, United Kingdom
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Nestoras Kargios
- Institute of Biological Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, United Kingdom
| | - Areti Mallioura
- Institute of Biological Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, United Kingdom
| | - Narcis Fernandez-Fuentes
- Institute of Biological Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, United Kingdom
| | - Nicola Cavallari
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - John H. Doonan
- Institute of Biological Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, United Kingdom
- John H. Doonan,
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The Emerging Landscape of p53 Isoforms in Physiology, Cancer and Degenerative Diseases. Int J Mol Sci 2019; 20:ijms20246257. [PMID: 31835844 PMCID: PMC6941119 DOI: 10.3390/ijms20246257] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 11/26/2019] [Accepted: 12/09/2019] [Indexed: 12/13/2022] Open
Abstract
p53, first described four decades ago, is now established as a master regulator of cellular stress response, the “guardian of the genome”. p53 contributes to biological robustness by behaving in a cellular-context dependent manner, influenced by several factors (e.g., cell type, active signalling pathways, the type, extent and intensity of cellular damage, cell cycle stage, nutrient availability, immune function). The p53 isoforms regulate gene transcription and protein expression in response to the stimuli so that the cell response is precisely tuned to the cell signals and cell context. Twelve isoforms of p53 have been described in humans. In this review, we explore the interactions between p53 isoforms and other proteins contributing to their established cellular functions, which can be both tumour-suppressive and oncogenic in nature. Evidence of p53 isoform in human cancers is largely based on RT-qPCR expression studies, usually investigating a particular type of isoform. Beyond p53 isoform functions in cancer, it is implicated in neurodegeneration, embryological development, progeroid phenotype, inflammatory pathology, infections and tissue regeneration, which are described in this review.
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Influence of p53 Isoform Expression on Survival in High-Grade Serous Ovarian Cancers. Sci Rep 2019; 9:5244. [PMID: 30918304 PMCID: PMC6437169 DOI: 10.1038/s41598-019-41706-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 03/14/2019] [Indexed: 11/08/2022] Open
Abstract
High-grade serous ovarian carcinoma (HGSOC) is characterised by alterations in the p53 pathway. The expression levels of p53 isoforms have been shown to be associated with patient survival in several cancers. This study examined the predictive and prognostic effects of the expression levels of TP53 pre-mRNA splicing isoforms and TP53 mutations in tumour tissues in 40 chemotherapy responders and 29 non-responders with HGSOC. The mRNA expression levels from total p53, and total Δ133p53, p53β, p53γ isoforms were determined by RT-qPCR, and TP53 mutation status by targeted massive parallel sequencing. The results from these analyses were correlated with the clinical outcome parameters. No differential expression of p53 isoforms could be detected between the chemosensitive and chemoresistant subgroups. In a multivariate Cox regression model, high levels of total Δ133p53 were found to be an independent prognosticator for improved overall survival (HR = 0.422, p = 0.018, 95% CI: 0.207–0.861) and reached borderline significance for progression-free survival (HR = 0.569, p = 0.061, 95% CI: 0.315–1.027). TP53 mutations resulting in loss of function or located at known hotspots were predictive of tumour characteristics and disease progression. These findings suggest that total Δ133p53 mRNA can be a biomarker for survival in HGSOC.
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Abstract
High-grade serous ovarian carcinoma (HGSOC) is characterised by alterations in the p53 pathway. The expression levels of p53 isoforms have been shown to be associated with patient survival in several cancers. This study examined the predictive and prognostic effects of the expression levels of TP53 pre-mRNA splicing isoforms and TP53 mutations in tumour tissues in 40 chemotherapy responders and 29 non-responders with HGSOC. The mRNA expression levels from total p53, and total Δ133p53, p53β, p53γ isoforms were determined by RT-qPCR, and TP53 mutation status by targeted massive parallel sequencing. The results from these analyses were correlated with the clinical outcome parameters. No differential expression of p53 isoforms could be detected between the chemosensitive and chemoresistant subgroups. In a multivariate Cox regression model, high levels of total Δ133p53 were found to be an independent prognosticator for improved overall survival (HR = 0.422, p = 0.018, 95% CI: 0.207-0.861) and reached borderline significance for progression-free survival (HR = 0.569, p = 0.061, 95% CI: 0.315-1.027). TP53 mutations resulting in loss of function or located at known hotspots were predictive of tumour characteristics and disease progression. These findings suggest that total Δ133p53 mRNA can be a biomarker for survival in HGSOC.
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Abstract
PURPOSE OF REVIEW Childhood blastomas, unlike adult cancers, originate from developing organs in which molecular and cellular features exhibit differentiation arrest and embryonic characteristics. Conventional cancer therapies, which rely on the generalized cytotoxic effect on rapidly dividing cells, may damage delicate organs in young children, leading to multiple late effects. Deep understanding of the biology of embryonal cancers is crucial in reshaping the cancer treatment paradigm for children. RECENT FINDINGS p53 plays a major physiological role in embryonic development, by controlling cell proliferation, differentiation and responses to cellular stress. Tumor suppressor function of p53 is commonly lost in adult cancers through genetic alterations. However, both somatic and germline p53 mutations are rare in childhood blastomas, suggesting that in these cancers, p53 may be inactivated through other mechanisms than mutation. In this review, we summarize current knowledge about p53 pathway inactivation in childhood blastomas (specifically neuroblastoma, retinoblastoma and Wilms' tumor) through various upstream mechanisms. Laboratory evidence and clinical trials of targeted therapies specific to exploiting p53 upstream regulators are discussed. SUMMARY Despite the low rate of inherent TP53 mutations, p53 pathway inactivation is a common denominator in childhood blastomas. Exploiting p53 and its regulators is likely to translate into more effective targeted therapies with minimal late effects for children. (see Video Abstract, Supplemental Digital Content 1, http://links.lww.com/COON/A23).
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Affiliation(s)
- Lixian Oh
- Department of Paediatrics, University of Malaya, Kuala Lumpur, Malaysia
| | - Hind Hafsi
- Institute of Advanced Biosciences, University of Grenoble-Alpes, La Tronche, France
| | - Pierre Hainaut
- Institute of Advanced Biosciences, University of Grenoble-Alpes, La Tronche, France
| | - Hany Ariffin
- Department of Paediatrics, University of Malaya, Kuala Lumpur, Malaysia
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Zhou L. P53 and Apoptosis in the Drosophila Model. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1167:105-112. [PMID: 31520351 DOI: 10.1007/978-3-030-23629-8_6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Human P53 (HsP53) is the most frequently mutated gene associated with cancers. Despite heightened research interest over the last four decades, a clear picture of how wild type HsP53 functions as the guardian against malignant transformation remains elusive. Studying the ortholog of P53 in the genetic model organism Drosophila melanogaster (DmP53) has revealed many interesting insights. This chapter focuses on recent findings that have shed light on how DmP53 -mediated apoptosis plays an important role in maintaining genome integrity, and how the immediate output of activated DmP53 is determined by the epigenetic landscape of individual cells.
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Affiliation(s)
- Lei Zhou
- Department of Molecular Genetics and Microbiology, UF Health Cancer Center, College of Medicine, University of Florida, Gainesville, FL, USA.
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Robin M, Issa AR, Santos CC, Napoletano F, Petitgas C, Chatelain G, Ruby M, Walter L, Birman S, Domingos PM, Calvi BR, Mollereau B. Drosophila p53 integrates the antagonism between autophagy and apoptosis in response to stress. Autophagy 2018; 15:771-784. [PMID: 30563404 DOI: 10.1080/15548627.2018.1558001] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The tumor suppressor TP53/p53 is a known regulator of apoptosis and macroautophagy/autophagy. However, the molecular mechanism by which TP53 regulates 2 apparently incompatible processes remains unknown. We found that Drosophila lacking p53 displayed impaired autophagic flux, higher caspase activation and mortality in response to oxidative stress compared with wild-type flies. Moreover, autophagy and apoptosis were differentially regulated by the p53 (p53B) and ΔNp53 (p53A) isoforms: while the former induced autophagy in differentiated neurons, which protected against cell death, the latter inhibited autophagy by activating the caspases Dronc, Drice, and Dcp-1. Our results demonstrate that the differential use of p53 isoforms combined with the antagonism between apoptosis and autophagy ensures the generation of an appropriate p53 biological response to stress.
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Affiliation(s)
- Marion Robin
- a Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland , Lyon , France
| | - Abdul Raouf Issa
- b Genes Circuits Rhythms and Neuropathology , Brain Plasticity Unit, CNRS, ESPCI Paris, Labex Memolife, PSL Research University , Paris , France.,e Department of Life Sciences , University of Trieste c/o CIB National Laboratory , Area Science Park , Trieste , Italy
| | - Cristiana C Santos
- c Instituto de Tecnologia Química e Biológica , Universidade Nova de Lisboa , Oeiras , Portugal
| | - Francesco Napoletano
- a Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland , Lyon , France.,e Department of Life Sciences , University of Trieste c/o CIB National Laboratory , Area Science Park , Trieste , Italy
| | - Céline Petitgas
- b Genes Circuits Rhythms and Neuropathology , Brain Plasticity Unit, CNRS, ESPCI Paris, Labex Memolife, PSL Research University , Paris , France
| | - Gilles Chatelain
- a Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland , Lyon , France
| | - Mathilde Ruby
- a Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland , Lyon , France
| | - Ludivine Walter
- a Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland , Lyon , France
| | - Serge Birman
- b Genes Circuits Rhythms and Neuropathology , Brain Plasticity Unit, CNRS, ESPCI Paris, Labex Memolife, PSL Research University , Paris , France
| | - Pedro M Domingos
- c Instituto de Tecnologia Química e Biológica , Universidade Nova de Lisboa , Oeiras , Portugal
| | - Brian R Calvi
- d Department of Biology , Indiana University , Bloomington , IN , USA
| | - Bertrand Mollereau
- a Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland , Lyon , France
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Szpotkowska J, Swiatkowska A, Ciesiołka J. Length and secondary structure of the 5' non-coding regions of mouse p53 mRNA transcripts - mouse as a model organism for p53 gene expression studies. RNA Biol 2018; 16:25-41. [PMID: 30518296 DOI: 10.1080/15476286.2018.1556084] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Transcription initiation sites of Trp53 gene in mice were determined using the 5'RACE method. Based on sequence alignment of the 5'-terminal regions of p53 mRNA in mammals, the site for the most abundant transcript turned out to be essentially identical with that determined for human TP53 gene and slightly differed for the longest transcripts, in mice and humans. Secondary structures of the 5' -terminal regions of the shorter, most abundant and the longest mouse transcripts were determined in vitro and the shorter transcript was also mapped in transfected mouse cells. For the first time, secondary structure models of the 5' terminus of two mouse p53 mRNAs were proposed. Comparing these models with the conservativeness of the nucleotide sequence of the 5'-terminal region of mRNA in mouse and other mammals, the possible function of the selected structural domains of this region was discussed. To elucidate the translation mechanisms, the two studied mRNAs were translated in the presence of an increasing concentration of the cap analog. For the longest transcript, the data suggested that IRES element(s) was/were involved in translation initiation. Additionally, changes in p53 synthesis under genotoxic and endoplasmic reticulum stress conditions in mouse cells were analyzed.
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Affiliation(s)
- Joanna Szpotkowska
- a Polish Academy of Sciences , Institute of Bioorganic Chemistry , Poznan , Poland
| | - Agata Swiatkowska
- a Polish Academy of Sciences , Institute of Bioorganic Chemistry , Poznan , Poland
| | - Jerzy Ciesiołka
- a Polish Academy of Sciences , Institute of Bioorganic Chemistry , Poznan , Poland
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Sauer E, Gauer B, Nascimento S, Nardi J, Göethel G, Costa B, Correia D, Matte U, Charão M, Arbo M, Duschl A, Moro A, Garcia SC. The role of B7 costimulation in benzene immunotoxicity and its potential association with cancer risk. ENVIRONMENTAL RESEARCH 2018; 166:91-99. [PMID: 29883905 DOI: 10.1016/j.envres.2018.05.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/24/2018] [Accepted: 05/26/2018] [Indexed: 06/08/2023]
Abstract
Benzene is a recognized human carcinogen; however, there are still some gaps in the knowledge regarding the mechanism of toxicity of this organic solvent and potential early biomarkers for the damage caused by it. In a previous study, our research group demonstrated that the adhesion molecules of the immune system (B7.1 and B7.2) could be potential biomarkers in the early detection of immunotoxicity caused by benzene exposure. Therefore, this study was developed to deepen the understanding regarding this important topic, aiming to contribute to the comprehension of the benzene toxicity mechanism mediated by B7.1 and B7.2 and its potential association with the risk of carcinogenicity. B7.1 and B7.2 protein expression in blood monocytes and B7.1 and B7.2 gene expression in PBMCs were evaluated. Additionally, complement C3 and C4 levels in serum were measured, as well as p53 gene expression in PBMCs. Seventy-four gas station workers (GSW group) and 71 non-occupationally exposed subjects (NEG) were evaluated. Our results demonstrated decreased levels of B7.1 and B7.2 protein and gene expression in the GSW group compared to the NEG (n = 71) (p < 0.01). Along the same lines, decreased levels of the complement system were observed in the GSW group (p < 0.01), demonstrating the impairment of this immune system pathway as well. Additionally, a reduction was observed in p53 gene expression in the GSA group (p < 0.01). These alterations were associated with both the benzene exposure biomarker evaluated, urinary trans, trans-muconic acid, and with exposure time (p < 0.05). Moreover, strong correlations were observed between the gene expression of p53 vs. B7.1 (r = 0.830; p < 0.001), p53 vs. B7.2 (r = 0.685; p < 0.001), and B7.1 vs. B7.2 (r = 0.702; p < 0.001). Taken together, these results demonstrate that the immune system co-stimulatory molecule pathway is affected by benzene exposure. Also, the decrease in p53 gene expression, even at low exposure levels, reinforces the carcinogenicity effect of benzene in this pathway. Therefore, our results suggest that the promotion of immune evasion together with a decrease in p53 gene expression may play an important role in the benzene toxicity mechanism. However, further and targeted studies are needed to confirm this proposition.
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Affiliation(s)
- Elisa Sauer
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Bruna Gauer
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Sabrina Nascimento
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Jessica Nardi
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Gabriela Göethel
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Bárbara Costa
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Douglas Correia
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Ursula Matte
- Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Mariele Charão
- Instituto de Ciências das Saúde, Universidade Feevale, Novo Hamburgo, RS, Brazil
| | - Marcelo Arbo
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Albert Duschl
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | - Angela Moro
- Faculdade Especializada na Área de Saúde do Rio Grande do Sul, Passo Fundo, RS, Brazil
| | - Solange Cristina Garcia
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
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p53 Isoforms and Their Implications in Cancer. Cancers (Basel) 2018; 10:cancers10090288. [PMID: 30149602 PMCID: PMC6162399 DOI: 10.3390/cancers10090288] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 08/18/2018] [Accepted: 08/18/2018] [Indexed: 01/10/2023] Open
Abstract
In this review we focus on the major isoforms of the tumor-suppressor protein p53, dysfunction of which often leads to cancer. Mutations of the TP53 gene, particularly in the DNA binding domain, have been regarded as the main cause for p53 inactivation. However, recent reports demonstrating abundance of p53 isoforms, especially the N-terminally truncated ones, in the cancerous tissues suggest their involvement in carcinogenesis. These isoforms are ∆40p53, ∆133p53, and ∆160p53 (the names indicate their respective N-terminal truncation). Due to the lack of structural and functional characterizations the modes of action of the p53 isoforms are still unclear. Owing to the deletions in the functional domains, these isoforms can either be defective in DNA binding or more susceptive to altered ‘responsive elements’ than p53. Furthermore, they may exert a ‘dominant negative effect’ or induce more aggressive cancer by the ‘gain of function’. One possible mechanism of p53 inactivation can be through tetramerization with the ∆133p53 and ∆160p53 isoforms—both lacking part of the DNA binding domain. A recent report and unpublished data from our laboratory also suggest that these isoforms may inactivate p53 by fast aggregation—possibly due to ectopic overexpression. We further discuss the evolutionary significance of the p53 isoforms.
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A mouse model of the Δ133p53 isoform: roles in cancer progression and inflammation. Mamm Genome 2018; 29:831-842. [PMID: 29992419 DOI: 10.1007/s00335-018-9758-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 07/05/2018] [Indexed: 01/19/2023]
Abstract
This review paper outlines studies on the Δ122p53 mouse, a model of the human Δ133p53 isoform, together with studies in other model organisms, cell culture, and where available, clinical investigations. In general, these studies imply that, in contrast to the canonical p53 tumor suppressor, Δ133p53 family members have oncogenic capability. Δ122p53 is multi-functional, conferring survival and proliferative advantages on cells, promoting invasion, metastasis and vascularization, as does Δ133p53. Cancers with high levels of Δ133p53 often have poor prognosis. Δ122p53 mediates its effects through the JAK-STAT and RhoA-ROCK signaling pathways. We propose that Δ133p53 isoforms have evolved as inflammatory signaling molecules to deal with the consequent tissue damage of p53 activation. However, if sustained expression of the isoforms occur, pathologies may result.
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43
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Regulation and function of p53: A perspective from Drosophila studies. Mech Dev 2018; 154:82-90. [PMID: 29800619 DOI: 10.1016/j.mod.2018.05.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 05/11/2018] [Accepted: 05/18/2018] [Indexed: 11/23/2022]
Abstract
Tp53 is a central regulator of cellular responses to stress and one of the most frequently mutated genes in human cancers. P53 is activated by a myriad of stress signals and drives specific cellular responses depending on stress nature, cell type and cellular context. Additionally to its classical functions in regulating cell cycle arrest, apoptosis and senescence, newly described non-canonical functions of p53 are increasingly coming under the spotlight as important functions not only for its role as a tumour suppressor but also for its non-cancer associated activities. Drosophila melanogaster is a valuable model to study multiple aspects of normal animal physiology, stress response and disease. In this review, we discuss the contribution of Drosophila studies to the current knowledge on p53 and highlight recent evidences pointing to p53 novel roles in promoting tissue homeostasis and metabolic adaptation.
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Marcel V, Nguyen Van Long F, Diaz JJ. 40 Years of Research Put p53 in Translation. Cancers (Basel) 2018; 10:E152. [PMID: 29883412 PMCID: PMC5977125 DOI: 10.3390/cancers10050152] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 05/15/2018] [Accepted: 05/18/2018] [Indexed: 12/18/2022] Open
Abstract
Since its discovery in 1979, p53 has shown multiple facets. Initially the tumor suppressor p53 protein was considered as a stress sensor able to maintain the genome integrity by regulating transcription of genes involved in cell cycle arrest, apoptosis and DNA repair. However, it rapidly came into light that p53 regulates gene expression to control a wider range of biological processes allowing rapid cell adaptation to environmental context. Among them, those related to cancer have been extensively documented. In addition to its role as transcription factor, scattered studies reported that p53 regulates miRNA processing, modulates protein activity by direct interaction or exhibits RNA-binding activity, thus suggesting a role of p53 in regulating several layers of gene expression not restricted to transcription. After 40 years of research, it appears more and more clearly that p53 is strongly implicated in translational regulation as well as in the control of the production and activity of the translational machinery. Translation control of specific mRNAs could provide yet unsuspected capabilities to this well-known guardian of the genome.
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Affiliation(s)
- Virginie Marcel
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, 69008 Lyon, France.
| | - Flora Nguyen Van Long
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, 69008 Lyon, France.
| | - Jean-Jacques Diaz
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, 69008 Lyon, France.
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45
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Duffy MJ, Synnott NC, Crown J. Mutant p53 in breast cancer: potential as a therapeutic target and biomarker. Breast Cancer Res Treat 2018; 170:213-219. [PMID: 29564741 DOI: 10.1007/s10549-018-4753-7] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/13/2018] [Indexed: 12/21/2022]
Abstract
OBJECTIVE The aim of this article is to discuss mutant p53 as a possible therapeutic target and biomarker for breast cancer. RESULTS TP53 (p53) is the most frequently mutated gene in invasive breast cancer. Although mutated in 30-35% of all cases, p53 is mutated in approximately 80% of triple-negative (TN) tumors (i.e., tumors negative for ER, PR, and HER2). Because of this high prevalence, mutated p53 is both a potential biomarker and therapeutic target for patients with breast cancer, especially for those with the TN subtype. Although several retrospective studies have investigated a potential prognostic and therapy predictive role for mutant p53 in breast cancer, the results to date are mixed. Thus, at present, mutant p53 cannot be recommended as a prognostic or therapy predictive biomarker in breast cancer. In contrast to the multiple reports on a potential biomarker role, few studies had until recently, investigated mutant p53 as a potential target for breast cancer treatment. In the last decade, however, several compounds have become available which can reactivate mutant p53 protein and convert it to a conformation with wild-type properties. Some of these compounds, especially PRIMA-1, APR-246 PK11007, and COTI-2, have been found to exhibit anticancer activity in preclinical models of breast cancer. CONCLUSION Since p53 is mutated in the vast majority of TN breast cancers, compounds such as APR-246, PK11007, and COTI-2 are potential treatments for patients with this subform of the disease. Further research is necessary to identify a potential biomarker role for mutant p53 in breast cancer.
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Affiliation(s)
- Michael J Duffy
- UCD Clinical Research Centre, St. Vincent's University Hospital, Dublin 4, Ireland. .,UCD School of Medicine, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland.
| | - Naoise C Synnott
- UCD School of Medicine, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - John Crown
- Department of Medical Oncology, St. Vincent's University Hospital, Dublin, Ireland
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Jiang W, Liu L, Chen Y. Simultaneous Detection of Human C-Terminal p53 Isoforms by Single Template Molecularly Imprinted Polymers (MIPs) Coupled with Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)-Based Targeted Proteomics. Anal Chem 2018; 90:3058-3066. [DOI: 10.1021/acs.analchem.7b02890] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Wenting Jiang
- School of Pharmacy, Nanjing Medical University, 818 Tian Yuan East Road, Nanjing, Jiangsu, China, 211166
| | - Liang Liu
- School of Pharmacy, Nanjing Medical University, 818 Tian Yuan East Road, Nanjing, Jiangsu, China, 211166
| | - Yun Chen
- School of Pharmacy, Nanjing Medical University, 818 Tian Yuan East Road, Nanjing, Jiangsu, China, 211166
- China State Key Laboratory of Reproductive Medicine, Nanjing, China 210029
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Zydowicz-Machtel P, Swiatkowska A, Popenda Ł, Gorska A, Ciesiołka J. Variants of the 5'-terminal region of p53 mRNA influence the ribosomal scanning and translation efficiency. Sci Rep 2018; 8:1533. [PMID: 29367734 PMCID: PMC5784139 DOI: 10.1038/s41598-018-20010-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 01/11/2018] [Indexed: 12/25/2022] Open
Abstract
The p53 protein is one of the major cell cycle regulators. The protein is expressed as at least twelve protein isoforms resulting from the use of alternative promoters, alternative splicing or downstream initiation codons. Importantly, there is growing evidence that translation initiation of p53 mRNA may be regulated by the structure and length of the naturally occurring variants of the 5′-terminal region of p53 mRNA transcripts. Here, several mRNA constructs were synthesized with variable length of the p53 5′-terminal regions and encoding luciferase reporter protein, and their translation was monitored continuously in situ in a rabbit reticulocyte lysate system. Moreover, four additional mRNA constructs were prepared. In two constructs, the structural context of AUG1 initiation codon was altered while in the other two constructs, characteristic hairpin motifs present in the p53 5′-terminal region were changed. Translation of the last two constructs was also performed in the presence of the cap analogue to test the function of the 5′-terminal region in cap-independent translation initiation. Superposition of several structural factors connected with the length of the 5′-terminal region, stable elements of the secondary structure, structural environment of the initiation codon and IRES elements greatly influenced the ribosomal scanning and translation efficiency.
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Affiliation(s)
- Paulina Zydowicz-Machtel
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Agata Swiatkowska
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Łukasz Popenda
- NanoBioMedical Centre, Adam Mickiewicz University in Poznan, Umultowska 85, 61-614, Poznan, Poland
| | - Agnieszka Gorska
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Jerzy Ciesiołka
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland.
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48
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Armstrong LC, Westlake G, Snow JP, Cawthon B, Armour E, Bowman AB, Ess KC. Heterozygous loss of TSC2 alters p53 signaling and human stem cell reprogramming. Hum Mol Genet 2017; 26:4629-4641. [PMID: 28973543 PMCID: PMC5886307 DOI: 10.1093/hmg/ddx345] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 08/28/2017] [Accepted: 09/01/2017] [Indexed: 12/21/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a pediatric disorder of dysregulated growth and differentiation caused by loss of function mutations in either the TSC1 or TSC2 genes, which regulate mTOR kinase activity. To study aberrations of early development in TSC, we generated induced pluripotent stem cells using dermal fibroblasts obtained from patients with TSC. During validation, we found that stem cells generated from TSC patients had a very high rate of integration of the reprogramming plasmid containing a shRNA against TP53. We also found that loss of one allele of TSC2 in human fibroblasts is sufficient to increase p53 levels and impair stem cell reprogramming. Increased p53 was also observed in TSC2 heterozygous and homozygous mutant human stem cells, suggesting that the interactions between TSC2 and p53 are consistent across cell types and gene dosage. These results support important contributions of TSC2 heterozygous and homozygous mutant cells to the pathogenesis of TSC and the important role of p53 during reprogramming.
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Affiliation(s)
- Laura C Armstrong
- Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, D4105 Medical Center North, Nashville, TN 37232, USA
| | - Grant Westlake
- Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, D4105 Medical Center North, Nashville, TN 37232, USA
| | - John P Snow
- Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, D4105 Medical Center North, Nashville, TN 37232, USA
| | - Bryan Cawthon
- Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, D4105 Medical Center North, Nashville, TN 37232, USA
| | - Eric Armour
- Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, D4105 Medical Center North, Nashville, TN 37232, USA
| | - Aaron B Bowman
- Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, D4105 Medical Center North, Nashville, TN 37232, USA
| | - Kevin C Ess
- Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, D4105 Medical Center North, Nashville, TN 37232, USA
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Katoch A, George B, Iyyappan A, Khan D, Das S. Interplay between PTB and miR-1285 at the p53 3'UTR modulates the levels of p53 and its isoform Δ40p53α. Nucleic Acids Res 2017; 45:10206-10217. [PMID: 28973454 PMCID: PMC5622325 DOI: 10.1093/nar/gkx630] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 07/26/2017] [Indexed: 01/21/2023] Open
Abstract
p53 and its translational isoform Δ40p53 are involved in many important cellular functions like cell cycle, cell proliferation, differentiation and metabolism. Expression of both the isoforms can be regulated at different steps. In this study, we explored the role of 3′UTR in regulating the expression of these two translational isoforms. We report that the trans acting factor, Polypyrimidine Tract Binding protein (PTB), also interacts specifically with 3′UTR of p53 mRNA and positively regulates expression of p53 isoforms. Our results suggest that there is interplay between miRNAs and PTB at the 3′UTR under normal and stress conditions like DNA damage. Interestingly, PTB showed some overlapping binding regions in the p53 3′UTR with miR-1285. In fact, knockdown of miR-1285 as well as expression of p53 3′UTR with mutated miR-1285 binding sites resulted in enhanced association of PTB with the 3′UTR, which provides mechanistic insights of this interplay. Taken together, the results provide a plausible molecular basis of how the interplay between miRNAs and the PTB protein at the 3′UTR can play pivotal role in fine tuning the expression of the two p53 isoforms.
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Affiliation(s)
- Aanchal Katoch
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
| | - Biju George
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
| | - Amrutha Iyyappan
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
| | - Debjit Khan
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
| | - Saumitra Das
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
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Cell cycle arrest through indirect transcriptional repression by p53: I have a DREAM. Cell Death Differ 2017; 25:114-132. [PMID: 29125603 PMCID: PMC5729532 DOI: 10.1038/cdd.2017.172] [Citation(s) in RCA: 411] [Impact Index Per Article: 58.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 09/10/2017] [Accepted: 09/13/2017] [Indexed: 12/22/2022] Open
Abstract
Activation of the p53 tumor suppressor can lead to cell cycle arrest. The key mechanism of p53-mediated arrest is transcriptional downregulation of many cell cycle genes. In recent years it has become evident that p53-dependent repression is controlled by the p53–p21–DREAM–E2F/CHR pathway (p53–DREAM pathway). DREAM is a transcriptional repressor that binds to E2F or CHR promoter sites. Gene regulation and deregulation by DREAM shares many mechanistic characteristics with the retinoblastoma pRB tumor suppressor that acts through E2F elements. However, because of its binding to E2F and CHR elements, DREAM regulates a larger set of target genes leading to regulatory functions distinct from pRB/E2F. The p53–DREAM pathway controls more than 250 mostly cell cycle-associated genes. The functional spectrum of these pathway targets spans from the G1 phase to the end of mitosis. Consequently, through downregulating the expression of gene products which are essential for progression through the cell cycle, the p53–DREAM pathway participates in the control of all checkpoints from DNA synthesis to cytokinesis including G1/S, G2/M and spindle assembly checkpoints. Therefore, defects in the p53–DREAM pathway contribute to a general loss of checkpoint control. Furthermore, deregulation of DREAM target genes promotes chromosomal instability and aneuploidy of cancer cells. Also, DREAM regulation is abrogated by the human papilloma virus HPV E7 protein linking the p53–DREAM pathway to carcinogenesis by HPV. Another feature of the pathway is that it downregulates many genes involved in DNA repair and telomere maintenance as well as Fanconi anemia. Importantly, when DREAM function is lost, CDK inhibitor drugs employed in cancer treatment such as Palbociclib, Abemaciclib and Ribociclib can compensate for defects in early steps in the pathway upstream from cyclin/CDK complexes. In summary, the p53–p21–DREAM–E2F/CHR pathway controls a plethora of cell cycle genes, can contribute to cell cycle arrest and is a target for cancer therapy.
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