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Smigiel JM, Taylor SE, Bryson BL, Tamagno I, Polak K, Jackson MW. Cellular plasticity and metastasis in breast cancer: a pre- and post-malignant problem. JOURNAL OF CANCER METASTASIS AND TREATMENT 2019; 5:47. [PMID: 32355893 PMCID: PMC7192216 DOI: 10.20517/2394-4722.2019.26] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
As a field we have made tremendous strides in treating breast cancer, with a decline in the past 30 years of overall breast cancer mortality. However, this progress is met with little affect once the disease spreads beyond the primary site. With a 5-year survival rate of 22%, 10-year of 13%, for those patients with metastatic breast cancer (mBC), our ability to effectively treat wide spread disease is minimal. A major contributing factor to this ineffectiveness is the complex make-up, or heterogeneity, of the primary site. Within a primary tumor, secreted factors, malignant and pre-malignant epithelial cells, immune cells, stromal fibroblasts and many others all reside alongside each other creating a dynamic environment contributing to metastasis. Furthermore, heterogeneity contributes to our lack of understanding regarding the cells' remarkable ability to undergo epithelial/non-cancer stem cell (CSC) to mesenchymal/CSC (E-M/CSC) plasticity. The enhanced invasion & motility, tumor-initiating potential, and acquired therapeutic resistance which accompanies E-M/CSC plasticity implicates a significant role in metastasis. While most work trying to understand E-M/CSC plasticity has been done on malignant cells, recent evidence is emerging concerning the ability for pre-malignant cells to undergo E-M/CSC plasticity and contribute to the metastatic process. Here we will discuss the importance of E-M/CSC plasticity within malignant and pre-malignant populations of the tumor. Moreover, we will discuss how one may potentially target these populations, ultimately disrupting the metastatic cascade and increasing patient survival for those with mBC.
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Affiliation(s)
- Jacob M. Smigiel
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Sarah E. Taylor
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Benjamin L. Bryson
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Ilaria Tamagno
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Kelsey Polak
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Mark W. Jackson
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA
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Lee JK, Bloom J, Zubeldia-Plazaola A, Garbe JC, Stampfer MR, LaBarge MA. Different culture media modulate growth, heterogeneity, and senescence in human mammary epithelial cell cultures. PLoS One 2018; 13:e0204645. [PMID: 30273377 PMCID: PMC6166958 DOI: 10.1371/journal.pone.0204645] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Accepted: 08/16/2018] [Indexed: 02/07/2023] Open
Abstract
The ability to culture normal human mammary epithelial cells (HMEC) greatly facilitates experiments that seek to understand both normal mammary cell biology and the many differences between normal and abnormal human mammary epithelia. To maximize in vivo relevance, the primary cell culture conditions should maintain cells in states that resemble in vivo as much as possible. Towards this goal, we compared the properties of HMEC strains from two different reduction mammoplasty tissues that were grown in parallel using different media and culture conditions. Epithelial organoids were initiated into three different media: two commonly used serum-free-media, MCDB 170-type (e.g. MEGM) and WIT-P, and a low stress media, M87A. Growth, lineage heterogeneity, p16 protein expression, and population doublings to senescence were measured for each culture condition. MCDB 170 caused rapid senescence and loss of heterogeneity within 2 to 3 passages, but some cultures went through the 1 to 2 month process of selection to generate clonal finite post-selection post-stasis cells. WIT-P caused impressive expansion of luminal cells in 2nd passage followed by their near complete disappearance by passage 4 and senescence shortly thereafter. M87A supported as much as twice the number of population doublings compared to either serum-free medium, and luminal and myoepithelial cells were present for as many as 8 passages. Thus, of the three media compared, WIT-P and MCDB 170 imposed rapid senescence and loss of lineage heterogeneity, phenotypes consistent with cells maintained in high-stress conditions, while M87A supported cultures that maintained multiple lineages and robust growth for up to 60 population doublings. In conjunction with previous studies examining the molecular properties of cultures grown in these media, we conclude that M87A medium is most able to support long-term culture of multiple lineages similar to in vivo conditions, thereby facilitating investigations of normal HMEC biology relevant to the mammary gland in situ.
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Affiliation(s)
- Jonathan K. Lee
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America
| | - Jessica Bloom
- Department of Population Sciences, Beckman Research Institute, City of Hope, Duarte, CA, United States of America
| | | | - James C. Garbe
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America
| | - Martha R. Stampfer
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America
- * E-mail: (MAL); (MRS)
| | - Mark A. LaBarge
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America
- Department of Population Sciences, Beckman Research Institute, City of Hope, Duarte, CA, United States of America
- * E-mail: (MAL); (MRS)
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Nucks1 synergizes with Trp53 to promote radiation lymphomagenesis in mice. Oncotarget 2018; 7:61874-61889. [PMID: 27542204 PMCID: PMC5308697 DOI: 10.18632/oncotarget.11297] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 08/01/2016] [Indexed: 12/22/2022] Open
Abstract
NUCKS1 is a 27 kD vertebrate-specific protein, with a role in the DNA damage response. Here, we show that after 4 Gy total-body X-irradiation, Trp53+/− Nucks1+/− mice more rapidly developed tumors, particularly thymic lymphoma (TL), than Trp53+/− mice. TLs in both cohorts showed loss of heterozygosity (LOH) of the Trp53+ allele in essentially all cases. In contrast, LOH of the Nucks1+ allele was rare. Nucks1 expression correlated well with Nucks1 gene dosage in normal thymi, but was increased in the majority of TLs from Trp53+/− Nucks1+/− mice, suggesting that elevated Nucks1 message may be associated with progression towards malignancy in vivo. Trp53+/− Nucks1+/− mice frequently succumbed to CD4- CD8- TLs harboring translocations involving Igh but not Tcra/d, indicating TLs in Trp53+/− Nucks1+/− mice mostly originated prior to the double positive stage and at earlier lineage than TLs in Trp53+/- mice. Monoclonal rearrangements at Tcrb were more prevalent in TLs from Trp53+/− Nucks1+/− mice, as was infiltration of primary TL cells to distant organs (liver, kidney and spleen). We propose that, in the context of Trp53 deficiency, wild type levels of Nucks1 are required to suppress radiation-induced TL, likely through the role of the NUCKS1 protein in the DNA damage response.
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Vrba L, Garbe JC, Stampfer MR, Futscher BW. A lincRNA connected to cell mortality and epigenetically-silenced in most common human cancers. Epigenetics 2016; 10:1074-83. [PMID: 26646903 PMCID: PMC4844203 DOI: 10.1080/15592294.2015.1106673] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Immortality is an essential characteristic of human carcinoma cells. We recently developed an efficient, reproducible method that immortalizes human mammary epithelial cells (HMEC) in the absence of gross genomic changes by targeting 2 critical senescence barriers. Consistent transcriptomic changes associated with immortality were identified using microarray analysis of isogenic normal finite pre-stasis, abnormal finite post-stasis, and immortal HMECs from 4 individuals. A total of 277 genes consistently changed in cells that transitioned from post-stasis to immortal. Gene ontology analysis of affected genes revealed biological processes significantly altered in the immortalization process. These immortalization-associated changes showed striking similarity to the gene expression changes seen in The Cancer Genome Atlas (TCGA) clinical breast cancer data. The most dramatic change in gene expression seen during the immortalization step was the downregulation of an unnamed, incompletely annotated transcript that we called MORT, for mortality, since its expression was closely associated with the mortal, finite lifespan phenotype. We show here that MORT (ZNF667-AS1) is expressed in all normal finite lifespan human cells examined to date and is lost in immortalized HMEC. MORT gene silencing at the mortal/immortal boundary was due to DNA hypermethylation of its CpG island promoter. This epigenetic silencing is also seen in human breast cancer cell lines and in a majority of human breast tumor tissues. The functional importance of DNA hypermethylation in MORT gene silencing is supported by the ability of 5-aza-2'-deoxycytidine to reactivate MORT expression. Analysis of TCGA data revealed deregulation of MORT expression due to DNA hypermethylation in 15 out of the 17 most common human cancers. The epigenetic silencing of MORT in a large majority of the common human cancers suggests a potential fundamental role in cellular immortalization during human carcinogenesis.
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Affiliation(s)
- Lukas Vrba
- a Arizona Cancer Center; The University of Arizona ; Tucson , AZ USA
| | - James C Garbe
- b Life Sciences Division; Lawrence Berkeley National Laboratory ; Berkeley , CA USA
| | - Martha R Stampfer
- a Arizona Cancer Center; The University of Arizona ; Tucson , AZ USA.,b Life Sciences Division; Lawrence Berkeley National Laboratory ; Berkeley , CA USA
| | - Bernard W Futscher
- a Arizona Cancer Center; The University of Arizona ; Tucson , AZ USA.,c Department of Pharmacology & Toxicology ; College of Pharmacy; The University of Arizona ; Tucson , AZ USA
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Parplys AC, Zhao W, Sharma N, Groesser T, Liang F, Maranon DG, Leung SG, Grundt K, Dray E, Idate R, Østvold AC, Schild D, Sung P, Wiese C. NUCKS1 is a novel RAD51AP1 paralog important for homologous recombination and genome stability. Nucleic Acids Res 2015; 43:9817-34. [PMID: 26323318 PMCID: PMC4787752 DOI: 10.1093/nar/gkv859] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 07/09/2015] [Accepted: 08/17/2015] [Indexed: 01/20/2023] Open
Abstract
NUCKS1 (nuclear casein kinase and cyclin-dependent kinase substrate 1) is a 27 kD chromosomal, vertebrate-specific protein, for which limited functional data exist. Here, we demonstrate that NUCKS1 shares extensive sequence homology with RAD51AP1 (RAD51 associated protein 1), suggesting that these two proteins are paralogs. Similar to the phenotypic effects of RAD51AP1 knockdown, we find that depletion of NUCKS1 in human cells impairs DNA repair by homologous recombination (HR) and chromosome stability. Depletion of NUCKS1 also results in greatly increased cellular sensitivity to mitomycin C (MMC), and in increased levels of spontaneous and MMC-induced chromatid breaks. NUCKS1 is critical to maintaining wild type HR capacity, and, as observed for a number of proteins involved in the HR pathway, functional loss of NUCKS1 leads to a slow down in DNA replication fork progression with a concomitant increase in the utilization of new replication origins. Interestingly, recombinant NUCKS1 shares the same DNA binding preference as RAD51AP1, but binds to DNA with reduced affinity when compared to RAD51AP1. Our results show that NUCKS1 is a chromatin-associated protein with a role in the DNA damage response and in HR, a DNA repair pathway critical for tumor suppression.
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Affiliation(s)
- Ann C Parplys
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Weixing Zhao
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Neelam Sharma
- Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Torsten Groesser
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Fengshan Liang
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - David G Maranon
- Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Stanley G Leung
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kirsten Grundt
- Department of Molecular Medicine, Institute of Basic Medical Science, University of Oslo, 0317 Oslo, Norway
| | - Eloïse Dray
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Rupa Idate
- Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Anne Carine Østvold
- Department of Molecular Medicine, Institute of Basic Medical Science, University of Oslo, 0317 Oslo, Norway
| | - David Schild
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Patrick Sung
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Claudia Wiese
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA
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Chang C, Niu Z, Gu N, Zhao W, Wang G, Jia Y, Li D, Xu C. Analysis of the ways and methods of signaling pathways in regulating cell cycle of NIH3T3 at transcriptional level. BMC Cell Biol 2015; 16:25. [PMID: 26511608 PMCID: PMC4625951 DOI: 10.1186/s12860-015-0071-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 10/19/2015] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND To analyze the ways and methods of signaling pathways in regulating cell cycle progression of NIH3T3 at transcriptional level, we modeled cell cycle of NIH3T3 and found that G1 phase of NIH3T3 cell cycle was at 5-15 h after synchronization, S phase at 15-21 h, G2 phase at 21-22 h, M phase at 22-25 h. RESULTS Mouse Genome 430 2.0 microarray was used to detect the gene expression profiles of the model, and results showed remarkable changes in the expressions of 64 cell cycle genes and 960 genes associated with other physiological activity during the cell cycle of NIH3T3. For the next step, IPA software was used to analyze the physiological activities, cell cycle genes-associated signal transduction activities and their regulatory roles of these genes in cell cycle progression, and our results indicated that the reported genes were involved in 17 signaling pathways in the regulation of cell cycle progression. Newfound genes such as PKC, RAS, PP2A, NGR and PI3K etc. belong to the functional category of molecular mechanism of cancer, cyclins and cell cycle regulation HER-2 signaling in breast cancer signaling pathways. These newfound genes could promote DNA damage repairment and DNA replication progress, regulate the metabolism of protein, and maintain the cell cycle progression of NIH3T3 modulating the reported genes CCND1 and C-FOS. CONCLUSION All of the aforementioned signaling pathways interacted with the cell cycle network, indicating that NIH3T3 cell cycle was regulated by a number of signaling pathways.
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Affiliation(s)
- Cuifang Chang
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Zhipeng Niu
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Ningning Gu
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Weiming Zhao
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Gaiping Wang
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Yifeng Jia
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Deming Li
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
| | - Cunshuan Xu
- College of Life Science, Henan Normal University, No. 46, Construction East Road, Xinxiang, 453007, Henan Province, P. R. China. .,State Key Laboratory Cultivation Base for Cell Differentiation Regulation, Henan Normal University, Xinxiang, 453007, P. R. China.
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Lee JK, Garbe JC, Vrba L, Miyano M, Futscher BW, Stampfer MR, LaBarge MA. Age and the means of bypassing stasis influence the intrinsic subtype of immortalized human mammary epithelial cells. Front Cell Dev Biol 2015; 3:13. [PMID: 25815289 PMCID: PMC4356162 DOI: 10.3389/fcell.2015.00013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 02/17/2015] [Indexed: 11/23/2022] Open
Abstract
Based on molecular features, breast cancers are grouped into intrinsic subtypes that have different prognoses and therapeutic response profiles. With increasing age, breast cancer incidence increases, with hormone receptor-positive and other luminal-like subtype tumors comprising a majority of cases. It is not known at what stage of tumor progression subtype specification occurs, nor how the process of aging affects the intrinsic subtype. We examined subtype markers in immortalized human mammary epithelial cell lines established following exposure of primary cultured cell strains to a two-step immortalization protocol that targets the two main barriers to immortality: stasis (stress-associated senescence) and replicative senescence. Cell lines derived from epithelial cells obtained from non-tumorous pre- and post-menopausal breast surgery tissues were compared. Additionally, comparisons were made between lines generated using two different genetic interventions to bypass stasis: transduction of either an shRNA that down-regulated p16INK4A, or overexpressed constitutive active cyclin D1/CDK2. In all cases, the replicative senescence barrier was bypassed by transduction of c-Myc. Cells from all resulting immortal lines exhibited normal karyotypes. Immunofluorescence, flow cytometry, and gene expression analyses of lineage-specific markers were used to categorize the intrinsic subtypes of the immortalized lines. Bypassing stasis with p16 shRNA in young strains generated cell lines that were invariably basal-like, but the lines examined from older strains exhibited some luminal features such as keratin 19 and estrogen receptor expression. Overexpression of cyclin D1/CDK2 resulted in keratin 19 positive, luminal-like cell lines from both young and old strains, and the lines examined from older strains exhibited estrogen receptor expression. Thus age and the method of bypassing stasis independently influence the subtype of immortalized human mammary epithelial cells.
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Affiliation(s)
- Jonathan K Lee
- Life Sciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA
| | - James C Garbe
- Life Sciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA
| | - Lukas Vrba
- Arizona Cancer Center, The University of Arizona Tucson, AZ, USA ; College of Pharmacy, Department of Pharmacology and Toxicology, The University of Arizona Tucson, AZ, USA
| | - Masaru Miyano
- Life Sciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA
| | - Bernard W Futscher
- Arizona Cancer Center, The University of Arizona Tucson, AZ, USA ; College of Pharmacy, Department of Pharmacology and Toxicology, The University of Arizona Tucson, AZ, USA
| | - Martha R Stampfer
- Life Sciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA ; Arizona Cancer Center, The University of Arizona Tucson, AZ, USA
| | - Mark A LaBarge
- Life Sciences Division, Lawrence Berkeley National Laboratory Berkeley, CA, USA
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Zwemer LM, Bianchi DW. The amniotic fluid transcriptome as a guide to understanding fetal disease. Cold Spring Harb Perspect Med 2015; 5:cshperspect.a023101. [PMID: 25680981 DOI: 10.1101/cshperspect.a023101] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Numerous recent studies have shown the power of cell-free fetal RNA, obtained from amniotic fluid supernatant, to report on the development of the living fetus in real time. Examination of these transcripts on a genome-wide basis has led to new insights into the prenatal pathophysiology of multiple genetic, developmental, and environmental diseases. Each studied condition presents a unique, characteristic fetal transcriptome, which points to specific disrupted molecular pathways. These studies have also improved our knowledge of the normal development of the human fetus, revealing gestational age-related dynamic gene expression from a variety of organs. Analysis of the fetal transcriptome in normal and abnormal development has led to novel approaches for in utero prenatal treatment.
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Affiliation(s)
- Lillian M Zwemer
- Mother Infant Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
| | - Diana W Bianchi
- Mother Infant Research Institute, Tufts Medical Center, Boston, Massachusetts 02111
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Date DA, Burrows AC, Venere M, Jackson MW, Summers MK. Coordinated regulation of p31(Comet) and Mad2 expression is required for cellular proliferation. Cell Cycle 2013; 12:3824-32. [PMID: 24131926 DOI: 10.4161/cc.26811] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
p31(Comet) is a well-known interacting partner of the spindle assembly checkpoint (SAC) effector molecule Mad2. At the molecular level it is well established that p31(Comet) promotes efficient mitotic exit, specifically the metaphase-anaphase transition, by antagonizing Mad2 function. However, there is little knowledge of how p31(Comet) is regulated or the physiological importance of controlling p31(Comet). Here, we show that the Rb-E2F pathway regulates p31(Comet) expression. In multiple tumor types (including breast and lung) p31(Comet) expression is increased along with Mad2. Expression of this antagonist-target pair is coordinated in cells and correlated in cancer. Moreover, a narrow range of p31(Comet):Mad2 ratios is compatible with cellular viability. Our data suggest that coordinate regulation is important for the outgrowth of oncogenic cell populations. Our findings suggest that altered p31(Comet):Mad2 expression ratios may provide new insight into altered SAC function and the generation of chromosomal instability in tumors.
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Affiliation(s)
- Dipali A Date
- Department of Cancer Biology; Lerner Research Institute; Cleveland, OH USA
| | - Amy C Burrows
- Department of Cancer Biology; Lerner Research Institute; Cleveland, OH USA
| | - Monica Venere
- Department of Stem Cell Biology and Regenerative Medicine; Lerner Research Institute; Cleveland, OH USA
| | - Mark W Jackson
- Department of Pathology; Case Western Reserve University; Cleveland, OH USA; Case Comprehensive Cancer Center; Case Western Reserve University; Cleveland, OH USA
| | - Matthew K Summers
- Department of Cancer Biology; Lerner Research Institute; Cleveland, OH USA; Case Comprehensive Cancer Center; Case Western Reserve University; Cleveland, OH USA
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Epigenetic reprogramming governs EcSOD expression during human mammary epithelial cell differentiation, tumorigenesis and metastasis. Oncogene 2013; 33:358-68. [PMID: 23318435 DOI: 10.1038/onc.2012.582] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 10/09/2012] [Accepted: 10/26/2012] [Indexed: 12/24/2022]
Abstract
Expression of the antioxidant enzyme EcSOD in normal human mammary epithelial cells was not recognized until recently. Although expression of EcSOD was not detectable in non-malignant human mammary epithelial cells (HMEC) cultured in conventional two-dimensional (2D) culture conditions, EcSOD protein expression was observed in normal human breast tissues, suggesting that the 2D-cultured condition induces a repressive status of EcSOD gene expression in HMEC. With the use of laminin-enriched extracellular matrix (lrECM), we were able to detect expression of EcSOD when HMEC formed polarized acinar structures in a 3D-culture condition. Repression of the EcSOD-gene expression was again seen when the HMEC acini were sub-cultured as a monolayer, implying that lrECM-induced acinar morphogenesis is essential in EcSOD-gene activation. We have further shown the involvement of DNA methylation in regulating EcSOD expression in HMEC under these cell culture conditions. EcSOD mRNA expression was strongly induced in the 2D-cultured HMEC after treatment with a DNA methyltransferase inhibitor. In addition, epigenetic analyses showed a decrease in the degree of CpG methylation in the EcSOD promoter in the 3D versus 2D-cultured HMEC. More importantly, >80% of clinical mammary adenocarcinoma samples showed significantly decreased EcSOD mRNA and protein expression levels compared with normal mammary tissues and there is an inverse correlation between the expression levels of EcSOD and the clinical stages of breast cancer. Combined bisulfite restriction analysis analysis of some of the tumors also revealed an association of DNA methylation with the loss of EcSOD expression in vivo. Furthermore, overexpression of EcSOD inhibited breast cancer metastasis in both the experimental lung metastasis model and the syngeneic mouse model. This study suggests that epigenetic silencing of EcSOD may contribute to mammary tumorigenesis and that restoring the extracellular superoxide scavenging activity could be an effective strategy for breast cancer treatment.
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Labarge MA, Garbe JC, Stampfer MR. Processing of human reduction mammoplasty and mastectomy tissues for cell culture. J Vis Exp 2013:50011. [PMID: 23328888 PMCID: PMC3582686 DOI: 10.3791/50011] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Experimental examination of normal human mammary epithelial cell (HMEC) behavior, and how normal cells acquire abnormal properties, can be facilitated by in vitro culture systems that more accurately model in vivo biology. The use of human derived material for studying cellular differentiation, aging, senescence, and immortalization is particularly advantageous given the many significant molecular differences in these properties between human and commonly utilized rodent cells1-2. Mammary cells present a convenient model system because large quantities of normal and abnormal tissues are available due to the frequency of reduction mammoplasty and mastectomy surgeries. The mammary gland consists of a complex admixture of many distinct cell types, e.g., epithelial, adipose, mesenchymal, endothelial. The epithelial cells are responsible for the differentiated mammary function of lactation, and are also the origin of the vast majority of human breast cancers. We have developed methods to process mammary gland surgical discard tissues into pure epithelial components as well as mesenchymal cells3. The processed material can be stored frozen indefinitely, or initiated into primary culture. Surgical discard material is transported to the laboratory and manually dissected to enrich for epithelial containing tissue. Subsequent digestion of the dissected tissue using collagenase and hyaluronidase strips stromal material from the epithelia at the basement membrane. The resulting small pieces of the epithelial tree (organoids) can be separated from the digested stroma by sequential filtration on membranes of fixed pore size. Depending upon pore size, fractions can be obtained consisting of larger ductal/alveolar pieces, smaller alveolar clusters, or stromal cells. We have observed superior growth when cultures are initiated as organoids rather than as dissociated single cells. Placement of organoids in culture using low-stress inducing media supports long-term growth of normal HMEC with markers of multiple lineage types (myoepithelial, luminal, progenitor)4-5. Sufficient numbers of cells can be obtained from one individual's tissue to allow extensive experimental examination using standardized cell batches, as well as interrogation using high throughput modalities. Cultured HMEC have been employed in a wide variety of studies examining the normal processes governing growth, differentiation, aging, and senescence, and how these normal processes are altered during immortal and malignant transformation4-15,16. The effects of growth in the presence of extracellular matrix material, other cell types, and/or 3D culture can be compared with growth on plastic5,15. Cultured HMEC, starting with normal cells, provide an experimentally tractable system to examine factors that may propel or prevent human aging and carcinogenesis.
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Affiliation(s)
- Mark A Labarge
- Life Science Division, Lawrence Berkeley National Laboratory, USA
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12
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Futscher BW. Epigenetic changes during cell transformation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 754:179-94. [PMID: 22956502 DOI: 10.1007/978-1-4419-9967-2_9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Malignant cancer emerges from normal healthy cells in a multistep -process that involves both genetic and epigenetic lesions. Both genetic and environmental inputs participate in driving the epigenetic changes that occur during human carcinogenesis. The pathologic changes seen in DNA methylation and histone posttranslational modifications are complex, deeply intertwined, and act in concert to produce malignant transformation. To better understand the causes and consequences of the pathoepigenetic changes in cancer formation, a variety of experimentally tractable human cell line model systems that accurately reflect the molecular alterations seen in the clinical disease have been developed. Results from studies using these cell line model systems suggest that early critical epigenetic events occur in a stepwise fashion prior to cell immortalization. These epigenetic steps coincide with the cell's transition through well-defined cell proliferation barriers of stasis and telomere dysfunction. Following cell immortalization, stressors, such as environmental toxicants, can induce malignant transformation in a process in which the epigenetic changes occur in a smoother progressive fashion, in contrast to the stark stepwise epigenetic changes seen prior to cell immortalization. It is hoped that developing a clearer understanding of the identity, timing, and consequences of these epigenetic lesions will prove useful in future clinical applications that range from early disease detection to therapeutic intervention in malignant cancer.
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Affiliation(s)
- Bernard W Futscher
- Department of Pharmacology and Toxicology, College of Pharmacy and The University of Arizona Cancer Center, The University of Arizona, Tucson, AZ 85724-5024, USA.
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Novak P, Stampfer MR, Munoz-Rodriguez JL, Garbe JC, Ehrich M, Futscher BW, Jensen TJ. Cell-type specific DNA methylation patterns define human breast cellular identity. PLoS One 2012; 7:e52299. [PMID: 23284978 PMCID: PMC3527522 DOI: 10.1371/journal.pone.0052299] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 11/12/2012] [Indexed: 12/14/2022] Open
Abstract
DNA methylation plays a role in a variety of biological processes including embryonic development, imprinting, X-chromosome inactivation, and stem cell differentiation. Tissue specific differential methylation has also been well characterized. We sought to extend these studies to create a map of differential DNA methylation between different cell types derived from a single tissue. Using three pairs of isogenic human mammary epithelial and fibroblast cells, promoter region DNA methylation was characterized using MeDIP coupled to microarray analysis. Comparison of DNA methylation between these cell types revealed nearly three thousand cell-type specific differentially methylated regions (ctDMRs). MassARRAY was performed upon 87 ctDMRs to confirm and quantify differential DNA methylation. Each of the examined regions exhibited statistically significant differences ranging from 10-70%. Gene ontology analysis revealed the overrepresentation of many transcription factors involved in developmental processes. Additionally, we have shown that ctDMRs are associated with histone related epigenetic marks and are often aberrantly methylated in breast cancer. Overall, our data suggest that there are thousands of ctDMRs which consistently exhibit differential DNA methylation and may underlie cell type specificity in human breast tissue. In addition, we describe the pathways affected by these differences and provide insight into the molecular mechanisms and physiological overlap between normal cellular differentiation and breast carcinogenesis.
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Affiliation(s)
- Petr Novak
- Arizona Cancer Center, The University of Arizona, Tucson, Arizona, USA.
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Locke WJ, Clark SJ. Epigenome remodelling in breast cancer: insights from an early in vitro model of carcinogenesis. Breast Cancer Res 2012; 14:215. [PMID: 23168266 PMCID: PMC4053120 DOI: 10.1186/bcr3237] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Epigenetic gene regulation has influence over a diverse range of cellular functions, including the maintenance of pluripotency, differentiation, and cellular identity, and is deregulated in many diseases, including cancer. Whereas the involvement of epigenetic dysregulation in cancer is well documented, much of the mechanistic detail involved in triggering these changes remains unclear. In the current age of genomics, the development of new sequencing technologies has seen an influx of genomic and epigenomic data and drastic improvements in both resolution and coverage. Studies in cancer cell lines and clinical samples using next-generation sequencing are rapidly delivering spectacular insights into the nature of the cancer genome and epigenome. Despite these improvements in technology, the timing and relationship between genetic and epigenetic changes that occur during the process of carcinogenesis are still unclear. In particular, what changes to the epigenome are playing a driving role during carcinogenesis and what influence the temporal nature of these changes has on cancer progression are not known. Understanding the early epigenetic changes driving breast cancer has the exciting potential to provide a novel set of therapeutic targets or early-disease biomarkers or both. Therefore, it is important to find novel systems that permit the study of initial epigenetic events that potentially occur during the first stages of breast cancer. Non-malignant human mammary epithelial cells (HMECs) provide an exciting in vitro model of very early breast carcinogenesis. When grown in culture, HMECs are able to temporarily escape senescence and acquire a pre-malignant breast cancer-like phenotype (variant HMECs, or vHMECs). Cultured HMECs are composed mainly of cells from the basal breast epithelial layer. Therefore, vHMECs are considered to represent the basal-like subtype of breast cancer. The transition from HMECs to vHMECs in culture recapitulates the epigenomic phenomena that occur during the progression from normal breast to pre-malignancy. Therefore, the HMEC model system provides the unique opportunity to study the very earliest epigenomic aberrations occurring during breast carcinogenesis and can give insight into the sequence of epigenomic events that lead to breast malignancy. This review provides an overview of epigenomic research in breast cancer and discusses in detail the utility of the HMEC model system to discover early epigenomic changes involved in breast carcinogenesis.
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Abstract
Cancer patients' outcome and survival depends on the early diagnosis of malignant lesions. Several investigation methods used for the prevention and early detection strategies have specific limitations. More recently, epigenetic changes have been considered one of the most promising tools for the early diagnosis of cancer. Some of these epigenetic alterations including promoter hypermethylation of genes like P16INK4a, BRCA1, BRCA2, ERα and RARβ2, APC, and RASSF1A have been associated with early stages of mammary gland tumorigenesis and have been suggested to be included in the models that evaluate individual breast cancer risk. In lung cancer, P16INK4a and MGMT gene hypermethylation was observed in sputum years before clinical manifestation of the squamous cell carcinoma among smokers. Loss of GSTP1 function by DNA hypermethylation together with changes in the methylation levels of repetitive elements like LINE-1 and Sat2 was reported in prostatic preneoplastic lesions. Also, DNA hypermethylation for hMLH1 and MGMT DNA repair genes was reported in precursor lesions to colorectal cancer. These epigenetic alterations may be influenced by factors such as xenoestrogens, folate, and multivitamins. Detection of these changes may help determining cancer susceptibility and early diagnosis.
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Moreno E, Plano D, Lamberto I, Font M, Encío I, Palop JA, Sanmartín C. Sulfur and selenium derivatives of quinazoline and pyrido[2,3-d]pyrimidine: synthesis and study of their potential cytotoxic activity in vitro. Eur J Med Chem 2011; 47:283-98. [PMID: 22104973 DOI: 10.1016/j.ejmech.2011.10.056] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Revised: 10/25/2011] [Accepted: 10/28/2011] [Indexed: 12/21/2022]
Abstract
The synthesis, cytotoxic activities and selectivities of 35 derivatives related to quinazoline and pyrido[2,3-d]pyrimidine are described. The synthesized compounds were screened in vitro against four tumoral cell lines - leukemia (CCRF-CEM), colon (HT-29), lung (HTB-54) and breast (MCF-7) - and two cell lines derived from non-malignant cell lines, one mammary (184B5) and one from bronchial epithelium (BEAS-2B). MCF-7 and HTB-54 were the most sensitive cell lines with GI(50) values below 10μM for eleven and ten compounds, respectively. Two compounds (2o and 3a) were identified that evoked a marked cytotoxic effect in all cell lines tested and one compound, 7h, was potent and selective against MCF-7. A preliminary study into the mechanism of the potent derivatives 2o, 3a and 7h indicated that the cytotoxic activities of these compounds might be mediated by inducing cell death without affecting cell cycle phases.
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Affiliation(s)
- Esther Moreno
- Sección de síntesis, Departamento de Química Orgánica y Farmacéutica, University of Navarra, Irunlarrea, 1, E-31008 Pamplona, Spain
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17
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Synthesis, characterization, crystal structure and cytotoxicity of 2,4-bis(selenomethyl)quinazoline. Struct Chem 2011. [DOI: 10.1007/s11224-011-9816-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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18
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Jeanes AI, Maya-Mendoza A, Streuli CH. Cellular microenvironment influences the ability of mammary epithelia to undergo cell cycle. PLoS One 2011; 6:e18144. [PMID: 21479230 PMCID: PMC3066216 DOI: 10.1371/journal.pone.0018144] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Accepted: 02/25/2011] [Indexed: 12/11/2022] Open
Abstract
The use of cell culture models is a principal and fundamental technology used in
understanding how mammalian cells work. However, for some cell types such as
mammary epithelia, the lines selected for extended culture are often transformed
or have chromosomal abnormalities, while primary cultures have such a curtailed
lifespan that their use is restricted. For example, mammary luminal epithelial
cells (MECs) are used to study mechanisms of breast cancer, but the
proliferation of primary cell cultures is highly limited. Here we describe the
establishment of a new culture system to allow extended analysis of cultures of
primary mouse MECs. In 2D monolayer culture, primary MECs showed a burst of
proliferation 2–3 days post isolation, after which cell cycle decreased
substantially. Addition of mammary epithelial growth factors, such as Epidermal
Growth Factor, Fibroblast Growth Factor-2, Hepatocyte Growth Factor, and
Receptor Activator for Nuclear Factor κB Ligand, or extracellular matrix
proteins did not maintain their proliferation potential, neither did replating
the cells to increase the mitogenic response. However, culturing MECs directly
after tissue extraction in a 3D microenvironment consisting of basement membrane
proteins, extended the time in culture in which the cells could proliferate. Our
data reveal that the cellular microenvironment has profound effects on the
proliferative properties of the mammary epithelia and is dominant over growth
factors. Moreover, manipulating the cellular environment using this novel method
can maintain the proliferative potential of primary MECs, thus enabling cell
cycle to be studied as an endpoint after gene transfer or gene deletion
experiments.
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Affiliation(s)
- Alexa I Jeanes
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
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Plano D, Moreno E, Font M, Encío I, Palop JA, Sanmartín C. Synthesis and in vitro Anticancer Activities of some Selenadiazole Derivatives. Arch Pharm (Weinheim) 2010; 343:680-91. [PMID: 21110339 DOI: 10.1002/ardp.201000014] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Daniel Plano
- Departamento de Química Orgánica y Farmacéutica, University of Navarra, Pamplona, Spain
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Abstract
Various heat shock proteins, including Hsp72, are strongly upregulated in cancers, but their significance for tumor emergence and growth is poorly understood. Here we review recent data from several labs to indicate that Hsps, including Hsp72, are critical for growth of transformed but not normal cells. By manipulating expression and activity of Hsp72 and several oncogenes, it was shown that Hsp72 suppresses oncogene-induced senescence, thus allowing proliferation of cancer cells. Importantly, Hsp72 is able to suppress both p53-dependent and p53-independent senescence pathways. We propose that targeting Hsp72 may be a promising approach toward development of novel cancer therapies.
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Affiliation(s)
- Michael Sherman
- Department of Biochemistry, Boston University Medical School, Boston, Massachusetts, USA.
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21
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Abstract
Overexpression of Ras(G12V) in primary cells induces a permanent growth arrest called oncogene-induced senescence (OIS) that serves as a fail-safe mechanism against malignant transformation. We have performed a genome-wide small interfering RNA (siRNA) screen and a microRNA (miRNA) screen to identify mediators of OIS and show that siRNA-mediated knockdown of p21(Waf1/Cip1) rescues from Ras(G12V)-induced senescence in human mammary epithelial cells (HMECs). Moreover, we isolated a total of 28 miRNAs that prevented Ras(G12V)-induced growth arrest, among which all of the miR-106b family members were present. In addition, we obtained a number of hits, miR-130b, miR-302a, miR-302b, miR302c, miR-302d, miR-512-3p and miR-515-3p with seed sequences very similar to miR-106b family members. We show that overexpression of all these miRNAs rescues HMECs from Ras(G12V)-induced senescence by prevention of Ras(G12V)-induced upregulation of p21(Waf1/Cip1). Our results establish an important role for the cell cycle inhibitor p21(Waf1/Cip1) in growth control of HMECs and extend the repertoire of miRNAs that modulate the activity of this tumour suppressor.
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22
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Zock JM. Applications of high content screening in life science research. Comb Chem High Throughput Screen 2009; 12:870-76. [PMID: 19938341 PMCID: PMC2841426 DOI: 10.2174/138620709789383277] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Revised: 08/05/2008] [Accepted: 09/03/2008] [Indexed: 12/18/2022]
Abstract
Over the last decade, imaging as a detection mode for cell based assays has opened a new world of opportunities to measure "phenotypic endpoints" in both current and developing biological models. These "high content" methods combine multiple measurements of cell physiology, whether it comes from sub-cellular compartments, multicellular structures, or model organisms. The resulting multifaceted data can be used to derive new insights into complex phenomena from cell differentiation to compound pharmacology and toxicity. Exploring the major application areas through review of the growing compendium of literature provides evidence that this technology is having a tangible impact on drug discovery and the life sciences.
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Affiliation(s)
- Joseph M Zock
- Thermo Fisher Scientific, 100 Technology Dr, Pittsburgh, PA 15219, USA.
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23
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Collins MA. Generating 'omic knowledge': the role of informatics in high content screening. Comb Chem High Throughput Screen 2009; 12:917-25. [PMID: 19531005 PMCID: PMC2885606 DOI: 10.2174/138620709789383259] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2008] [Revised: 08/19/2008] [Accepted: 09/03/2008] [Indexed: 12/30/2022]
Abstract
High Content Screening (HCS) and High Content Analysis (HCA) have emerged over the past 10 years as a powerful technology for both drug discovery and systems biology. Founded on the automated, quantitative image analysis of fluorescently labeled cells or engineered cell lines, HCS provides unparalleled levels of multi-parameter data on cellular events and is being widely adopted, with great benefits, in many aspects of life science from gaining a better understanding of disease processes, through better models of toxicity, to generating systems views of cellular processes. This paper looks at the role of informatics and bioinformatics in both enabling and driving HCS to further our understanding of both the genome and the cellome and looks into the future to see where such deep knowledge could take us.
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Affiliation(s)
- Mark A Collins
- Cellular Imaging & Analysis, Thermo Fisher Scientific, Pittsburgh, PA 15219, USA.
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Gorski JJ, James CR, Quinn JE, Stewart GE, Staunton KC, Buckley NE, McDyer FA, Kennedy RD, Wilson RH, Mullan PB, Harkin DP. BRCA1 transcriptionally regulates genes associated with the basal-like phenotype in breast cancer. Breast Cancer Res Treat 2009; 122:721-31. [PMID: 19882246 DOI: 10.1007/s10549-009-0565-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Accepted: 09/17/2009] [Indexed: 01/16/2023]
Abstract
Expression profiling of BRCA1-deficient tumours has identified a pattern of gene expression similar to basal-like breast tumours. In this study, we examine whether a BRCA1-dependent transcriptional mechanism may underpin the link between BRCA1 and basal-like phenotype. In methods section, the mRNA and protein were harvested from a number of BRCA1 mutant and wild-type breast cancer cell lines and from matched isogenic controls. Microarray-based expression profiling was used to identify potential BRCA1-regulated transcripts. These gene targets were then validated (by in silico analysis of tumour samples) by real-time PCR and Western blot analysis. Chromatin immunoprecipitation (ChIP) assays were used to confirm recruitment of BRCA1 to specific promoters. In results, we demonstrate that functional BRCA1 represses the expression of cytokeratins 5(KRT5) and 17(KRT17) and p-Cadherin (CDH3) in HCC1937 and T47D breast cancer cell lines at both mRNA and protein level. ChIP assays demonstrate that BRCA1 is recruited to the promoters of KRT5, KRT17 and CDH3, and re-ChIP assays confirm that BRCA1 is recruited independently to form c-Myc and Sp1 complexes on the CDH3 promoter. We show that siRNA-mediated inhibition of endogenous c-Myc (and not Sp1) results in a marked increase in CDH3 expression analogous to that observed following the inhibition of endogenous BRCA1. The data provided suggest a model whereby BRCA1 and c-Myc form a repressor complex on the promoters of specific basal genes and represent a potential mechanism to explain the observed overexpression of key basal markers in BRCA1-deficient tumours.
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Affiliation(s)
- Julia J Gorski
- Department of Oncology, Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast BT9 7BL, N. Ireland, UK.
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Garbe JC, Bhattacharya S, Merchant B, Bassett E, Swisshelm K, Feiler HS, Wyrobek AJ, Stampfer MR. Molecular distinctions between stasis and telomere attrition senescence barriers shown by long-term culture of normal human mammary epithelial cells. Cancer Res 2009; 69:7557-68. [PMID: 19773443 DOI: 10.1158/0008-5472.can-09-0270] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Normal human epithelial cells in culture have generally shown a limited proliferative potential of approximately 10 to 40 population doublings before encountering a stress-associated senescence barrier (stasis) associated with elevated levels of cyclin-dependent kinase inhibitors p16 and/or p21. We now show that simple changes in medium composition can expand the proliferative potential of human mammary epithelial cells (HMEC) initiated as primary cultures to 50 to 60 population doublings followed by p16-positive, senescence-associated beta-galactosidase-positive stasis. We compared the properties of growing and senescent pre-stasis HMEC with growing and senescent post-selection HMEC, that is, cells grown in a serum-free medium that overcame stasis via silencing of p16 expression and that display senescence associated with telomere dysfunction. Cultured pre-stasis populations contained cells expressing markers associated with luminal and myoepithelial HMEC lineages in vivo in contrast to the basal-like phenotype of the post-selection HMEC. Gene transcript and protein expression, DNA damage-associated markers, mean telomere restriction fragment length, and genomic stability differed significantly between HMEC populations at the stasis versus telomere dysfunction senescence barriers. Senescent isogenic fibroblasts showed greater similarity to HMEC at stasis than at telomere dysfunction, although their gene transcript profile was distinct from HMEC at both senescence barriers. These studies support our model of the senescence barriers encountered by cultured HMEC in which the first barrier, stasis, is retinoblastoma-mediated and independent of telomere length, whereas a second barrier (agonescence or crisis) results from telomere attrition leading to telomere dysfunction. Additionally, the ability to maintain long-term growth of genomically stable multilineage pre-stasis HMEC populations can greatly enhance experimentation with normal HMEC.
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Affiliation(s)
- James C Garbe
- Life Sciences Divisions, Lawrence Berkeley National Laboratory, Berkeley, California, USA
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Synthesis and pharmacological screening of several aroyl and heteroaroyl selenylacetic acid derivatives as cytotoxic and antiproliferative agents. Molecules 2009; 14:3313-38. [PMID: 19783927 PMCID: PMC6254723 DOI: 10.3390/molecules14093313] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 08/04/2009] [Accepted: 08/27/2009] [Indexed: 11/24/2022] Open
Abstract
The synthesis and cytotoxic activity of a series of twenty six aroyl and heteroaroyl selenylacetic acid derivatives of general formula Ar-CO-Se-CH2-COOH or Heterar-CO-Se-CH2-COOH are reported. The synthesis was carried out by reaction of acyl chlorides with sodium hydrogen selenide, prepared in situ, and this led to the formation of sodium aroylselenides that subsequently reacted with α-bromoacetic acid to produce the corresponding selenylacetic acid derivatives. All of the compounds were tested against a prostate cancer cell line (PC-3) and some of the more active compounds were assessed against a panel of four human cancer cell lines (CCRF-CEM, HTB-54, HT-29, MCF-7) and one mammary gland-derived non-malignant cell line (184B5). Some of the compounds exhibited remarkable cytotoxic and antiproliferative activities against MCF-7 and PC-3 that were higher than those of the reference compounds doxorubicin and etoposide, respectively. For example, in MCF-7 when Ar = phenyl, 3,5-dimethoxyphenyl or benzyl the TGI values were 3.69, 4.18 and 6.19 μM. On the other hand, in PC-3 these compounds showed values of 6.8, 4.0 and 2.9 μM. Furthermore, benzoylselenylacetic acid did not provoke apoptosis nor did it perturb the cell cycle in MCF-7.
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Drosos Y, Kouloukoussa M, Østvold AC, Grundt K, Goutas N, Vlachodimitropoulos D, Havaki S, Kollia P, Kittas C, Marinos E, Aleporou-Marinou V. NUCKS overexpression in breast cancer. Cancer Cell Int 2009; 9:19. [PMID: 19664271 PMCID: PMC2743642 DOI: 10.1186/1475-2867-9-19] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2009] [Accepted: 08/10/2009] [Indexed: 12/15/2022] Open
Abstract
Background NUCKS (Nuclear, Casein Kinase and Cyclin-dependent Kinase Substrate) is a nuclear, DNA-binding and highly phosphorylated protein. A number of reports show that NUCKS is highly expressed on the level of mRNA in several human cancers, including breast cancer. In this work, NUCKS expression on both RNA and protein levels was studied in breast tissue biopsies consisted of invasive carcinomas, intraductal proliferative lesions, benign epithelial proliferations and fibroadenomas, as well as in primary cultures derived from the above biopsies. Specifically, in order to evaluate the level of NUCKS protein in correlation with the histopathological features of breast disease, immunohistochemistry was employed on paraffin sections of breast biopsies of the above types. In addition, NUCKS expression was studied by means of Reverse Transcription PCR (RT-PCR), real-time PCR (qRT-PCR) and Western immunoblot analyses in the primary cell cultures developed from the same biopsies. Results The immunohistochemical Results showed intense NUCKS staining mostly in grade I and II breast carcinomas compared to normal tissues. Furthermore, NUCKS was moderate expressed in benign epithelial proliferations, such as adenosis and sclerosing adenosis, and highly expressed in intraductal lesions, specifically in ductal carcinomas in situ (DCIS). It is worth noting that all the fibroadenoma tissues examined were negative for NUCKS staining. RT-PCR and qRT-PCR showed an increase of NUCKS expression in cells derived from primary cultures of proliferative lesions and cancerous tissues compared to the ones derived from normal breast tissues and fibroadenomas. This increase was also confirmed by Western immunoblot analysis. Although NUCKS is a cell cycle related protein, its expression does not correlate with Ki67 expression, neither in tissue sections nor in primary cell cultures. Conclusion The results show overexpression of the NUCKS protein in a number of non malignant breast lesions and cancerous tissues. In particular, the NUCKS overexpression in ADH and DCIS indicates a significant role of this protein in neoplastic progression.
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Affiliation(s)
- Yiannis Drosos
- Department of Genetics and Biotechnology, Faculty of Biology, University of Athens, Panepistimioupoli, 15701 Ilissia, Greece.
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Königsberg R, Rögelsperger O, Jäger W, Thalhammer T, Klimpfinger M, Santis MD, Hudec M, Dittrich C. Cell Cycle Dysregulation Influences Survival in High Risk Breast Cancer Patients. Cancer Invest 2009; 26:734-40. [DOI: 10.1080/07357900801944864] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Novak P, Jensen TJ, Garbe JC, Stampfer MR, Futscher BW. Stepwise DNA methylation changes are linked to escape from defined proliferation barriers and mammary epithelial cell immortalization. Cancer Res 2009; 69:5251-8. [PMID: 19509227 DOI: 10.1158/0008-5472.can-08-4977] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The timing and progression of DNA methylation changes during carcinogenesis are not completely understood. To develop a timeline of aberrant DNA methylation events during malignant transformation, we analyzed genome-wide DNA methylation patterns in an isogenic human mammary epithelial cell (HMEC) culture model of transformation. To acquire immortality and malignancy, the cultured finite lifespan HMEC must overcome two distinct proliferation barriers. The first barrier, stasis, is mediated by the retinoblastoma protein and can be overcome by loss of p16(INK4A) expression. HMEC that escape stasis and continue to proliferate become genomically unstable before encountering a second more stringent proliferation barrier, telomere dysfunction due to telomere attrition. Rare cells that acquire telomerase expression may escape this barrier, become immortal, and develop further malignant properties. Our analysis of HMEC transitioning from finite lifespan to malignantly transformed showed that aberrant DNA methylation changes occur in a stepwise fashion early in the transformation process. The first aberrant DNA methylation step coincides with overcoming stasis, and results in few to hundreds of changes, depending on how stasis was overcome. A second step coincides with immortalization and results in hundreds of additional DNA methylation changes regardless of the immortalization pathway. A majority of these DNA methylation changes are also found in malignant breast cancer cells. These results show that large-scale epigenetic remodeling occurs in the earliest steps of mammary carcinogenesis, temporally links DNA methylation changes and overcoming cellular proliferation barriers, and provides a bank of potential epigenetic biomarkers that may prove useful in breast cancer risk assessment.
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Affiliation(s)
- Petr Novak
- Arizona Cancer Center, Tucson, AZ 85724, USA
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Functional genomic analysis of amniotic fluid cell-free mRNA suggests that oxidative stress is significant in Down syndrome fetuses. Proc Natl Acad Sci U S A 2009; 106:9425-9. [PMID: 19474297 DOI: 10.1073/pnas.0903909106] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
To characterize the differences between second trimester Down syndrome (DS) and euploid fetuses, we used Affymetrix microarrays to compare gene expression in uncultured amniotic fluid supernatant samples. Functional pathway analysis highlighted the importance of oxidative stress, ion transport, and G protein signaling in the DS fetuses. Further evidence supporting these results was derived by correlating the observed gene expression patterns to those of small molecule drugs via the Connectivity Map. Our results suggest that there are secondary adverse consequences of DS evident in the second trimester, leading to testable hypotheses about possible antenatal therapy for DS.
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Gochhait S, Dar S, Pal R, Gupta P, Bamezai RN. Expression of DNA damage response genes indicate progressive breast tumors. Cancer Lett 2009; 273:305-11. [DOI: 10.1016/j.canlet.2008.08.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Revised: 05/09/2008] [Accepted: 08/11/2008] [Indexed: 10/21/2022]
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Herschkowitz JI, He X, Fan C, Perou CM. The functional loss of the retinoblastoma tumour suppressor is a common event in basal-like and luminal B breast carcinomas. Breast Cancer Res 2008; 10:R75. [PMID: 18782450 PMCID: PMC2614508 DOI: 10.1186/bcr2142] [Citation(s) in RCA: 196] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Revised: 08/22/2008] [Accepted: 09/09/2008] [Indexed: 12/16/2022] Open
Abstract
Introduction Breast cancers can be classified using whole genome expression into distinct subtypes that show differences in prognosis. One of these groups, the basal-like subtype, is poorly differentiated, highly metastatic, genomically unstable, and contains specific genetic alterations such as the loss of tumour protein 53 (TP53). The loss of the retinoblastoma tumour suppressor encoded by the RB1 locus is a well-characterised occurrence in many tumour types; however, its role in breast cancer is less clear with many reports demonstrating a loss of heterozygosity that does not correlate with a loss of RB1 protein expression. Methods We used gene expression analysis for tumour subtyping and polymorphic markers located at the RB1 locus to assess the frequency of loss of heterozygosity in 88 primary human breast carcinomas and their normal tissue genomic DNA samples. Results RB1 loss of heterozygosity was observed at an overall frequency of 39%, with a high frequency in basal-like (72%) and luminal B (62%) tumours. These tumours also concurrently showed low expression of RB1 mRNA. p16INK4a was highly expressed in basal-like tumours, presumably due to a previously reported feedback loop caused by RB1 loss. An RB1 loss of heterozygosity signature was developed and shown to be highly prognostic, and was potentially a predictive marker of response to neoadjuvant chemotherapy. Conclusions These results suggest that the functional loss of RB1 is common in basal-like tumours, which may play a key role in dictating their aggressive biology and unique therapeutic responses.
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Affiliation(s)
- Jason I Herschkowitz
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, 27599, USA
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Hinshelwood RA, Clark SJ. Breast cancer epigenetics: normal human mammary epithelial cells as a model system. J Mol Med (Berl) 2008; 86:1315-28. [PMID: 18716754 DOI: 10.1007/s00109-008-0386-3] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Revised: 06/17/2008] [Accepted: 06/25/2008] [Indexed: 12/23/2022]
Abstract
DNA hypermethylation and histone modifications are two critical players involved in epigenetic regulation and together play an important role in silencing tumor-suppressor genes in all cancers, including breast cancer. One of the major challenges facing breast cancer researchers is the problem of how to identify critical genes that are epigenetically silenced early in cancer initiation as these genes provide potential early diagnostic and/or therapeutic targets for breast cancer management. This review will focus on compelling evidence that normal Human Mammary Epithelial Cells (HMECs) that escape senescence in culture mimic genetic and epigenetic events occurring in early breast cancer, and provide a valuable system to delineate the early steps in epigenetic deregulation that often occur during transition of a normal breast cell to a premalignant cell. In particular, this model system has been used to investigate the relationship between gene silencing, DNA methylation, histone modifications, and polycomb association that may occur early in oncogenic transformation.
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Affiliation(s)
- Rebecca A Hinshelwood
- The Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, NSW 2010, Australia
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Fridman AL, Tainsky MA. Critical pathways in cellular senescence and immortalization revealed by gene expression profiling. Oncogene 2008; 27:5975-87. [PMID: 18711403 DOI: 10.1038/onc.2008.213] [Citation(s) in RCA: 226] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Bypassing cellular senescence and becoming immortal is a prerequisite step in the tumorigenic transformation of a cell. It has long been known that loss of a key tumor suppressor gene, such as p53, is necessary, but not sufficient, for spontaneous cellular immortalization. Therefore, there must be additional mutations and/or epigenetic alterations required for immortalization to occur. Early work on these processes included somatic cell genetic studies to estimate the number of senescence genes, and microcell-mediated transfer of chromosomes into immortalized cells to identify putative senescence-inducing genetic loci. These principal studies laid the foundation for the field of senescence/immortalization, but were labor intensive and the results were somewhat limited. The advent of gene expression profiling and bioinformatics analysis greatly facilitated the identification of genes and pathways that regulate cellular senescence/immortalization. In this review, we present the findings of several gene expression profiling studies and supporting functional data, where available. We identified universal genes regulating senescence/immortalization and found that the key regulator genes represented six pathways: the cell cycle pRB/p53, cytoskeletal, interferon-related, insulin growth factor-related, MAP kinase and oxidative stress pathway. The identification of the genes and pathways regulating senescence/immortalization could provide novel molecular targets for the treatment and/or prevention of cancer.
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Affiliation(s)
- A L Fridman
- Department of Pathology, Program in Molecular Biology and Genetics, Barbara Ann Karmanos Cancer Institute, Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
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LaPan P, Zhang J, Pan J, Hill A, Haney SA. Single cell cytometry of protein function in RNAi treated cells and in native populations. BMC Cell Biol 2008; 9:43. [PMID: 18673568 PMCID: PMC2529295 DOI: 10.1186/1471-2121-9-43] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Accepted: 08/01/2008] [Indexed: 01/10/2023] Open
Abstract
Background High Content Screening has been shown to improve results of RNAi and other perturbations, however significant intra-sample heterogeneity is common and can complicate some analyses. Single cell cytometry can extract important information from subpopulations within these samples. Such approaches are important for immune cells analyzed by flow cytometry, but have not been broadly available for adherent cells that are critical to the study of solid-tumor cancers and other disease models. Results We have directly quantitated the effect of resolving RNAi treatments at the single cell level in experimental systems for both exogenous and endogenous targets. Analyzing the effect of an siRNA that targets GFP at the single cell level permits a stronger measure of the absolute function of the siRNA by gating to eliminate background levels of GFP intensities. Extending these methods to endogenous proteins, we have shown that well-level results of the knockdown of PTEN results in an increase in phospho-S6 levels, but at the single cell level, the correlation reveals the role of other inputs into the pathway. In a third example, reduction of STAT3 levels by siRNA causes an accumulation of cells in the G1 phase of the cell cycle, but does not induce apoptosis or necrosis when compared to control cells that express the same levels of STAT3. In a final example, the effect of reduced p53 levels on increased adriamycin sensitivity for colon carcinoma cells was demonstrated at the whole-well level using siRNA knockdown and in control and untreated cells at the single cell level. Conclusion We find that single cell analysis methods are generally applicable to a wide range of experiments in adherent cells using technology that is becoming increasingly available to most laboratories. It is well-suited to emerging models of signaling dysfunction, such as oncogene addition and oncogenic shock. Single cell cytometry can demonstrate effects on cell function for protein levels that differ by as little as 20%. Biological differences that result from changes in protein level or pathway activation state can be modulated directly by RNAi treatment or extracted from the natural variability intrinsic to cells grown under normal culture conditions.
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Affiliation(s)
- Peter LaPan
- Department of Biological Technologies, Oncology Research, Wyeth Research, 87 Cambridge Park Drive, Cambridge, MA 02140, USA.
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Different mutant/wild-type p53 combinations cause a spectrum of increased invasive potential in nonmalignant immortalized human mammary epithelial cells. Neoplasia 2008; 10:450-61. [PMID: 18472962 DOI: 10.1593/neo.08120] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Revised: 02/11/2008] [Accepted: 02/15/2008] [Indexed: 12/11/2022] Open
Abstract
Aberrations of p53 occur in most, if not all, human cancers. In breast cancer, p53 mutation is the most common genetic defect related to a single gene. Immortalized human mammary epithelial cells resemble the earliest forms of aberrant breast tissue growth but do not express many malignancy-associated phenotypes. We created a model of human mammary epithelial tumorigenesis by infecting hTERT-HME1 immortalized human mammary epithelial cells expressing wild-type p53 with four different mutant p53 constructs to determine the role of p53 mutation on the evolution of tumor phenotypes. We demonstrate that different mutant/wild-type p53 heterozygous models generate loss of function, dominant negative activity, and a spectrum of gain of function activities that induce varying degrees of invasive potential. We suggest that this model can be used to elucidate changes that occur in early stages of human mammary epithelial tumorigenesis. These changes may constitute novel biomarkers or reveal novel treatment modalities that could inhibit progression from primary to metastatic breast disease.
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Variable transcriptional activity of endogenous retroviruses in human breast cancer. J Virol 2007; 82:1808-18. [PMID: 18077721 DOI: 10.1128/jvi.02115-07] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Human endogenous retroviruses (HERVs) account for up to 9% of the human genome and include more than 800 elements related to betaretroviruses. While mouse mammary tumor virus (MMTV) is the accepted etiological agent of mammary tumors in mice, the role of retroviral elements in human breast cancer remains elusive. Here, we performed a comprehensive microarray-based analysis of overall retroviral transcriptional activities in 46 mammary gland tissue specimens representing pairs of nonmalignant and tumor samples from 23 patients. An analysis of nonmalignant tissue samples revealed a distinct, mammary gland-specific HERV expression profile that consists of 18 constitutively active HERV taxa. For corresponding tumor samples, a general trend toward lower levels of HERV transcription was observed, suggesting common regulatory mechanisms. In various subsets of patients, however, increased transcript levels of single class I HERV families (HERV-T, HERV-E, and HERV-F) and several class II families, including HML-6, were detected. An analysis of transcribed HML-6 sequences revealed either the activation of some or the increased activity of several proviral loci. No evidence for MMTV or human MMTV-like virus transcripts was found, indicating that transcriptionally active, MMTV analogous, exogenous viruses were not present in the breast cancer samples analyzed.
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LaBarge MA, Petersen OW, Bissell MJ. Of microenvironments and mammary stem cells. ACTA ACUST UNITED AC 2007; 3:137-46. [PMID: 17873346 PMCID: PMC3004778 DOI: 10.1007/s12015-007-0024-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 01/26/2023]
Abstract
In most adult tissues there reside pools of stem and progenitor cells inside specialized microenvironments referred to as niches. The niche protects the stem cells from inappropriate expansion and directs their critical functions. Thus guided, stem cells are able to maintain tissue homeostasis throughout the ebb and flow of metabolic and physical demands encountered over a lifetime. Indeed, a pool of stem cells maintains mammary gland structure throughout development, and responds to the physiological demands associated with pregnancy. This review discusses how stem cells were identified in both human and mouse mammary glands; each requiring different techniques that were determined by differing biological needs and ethical constraints. These studies together create a robust portrait of mammary gland biology and identify the location of the stem cell niche, elucidate a developmental hierarchy, and suggest how the niche might be manipulated for therapeutic benefit.
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Affiliation(s)
- Mark A LaBarge
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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