Mammalian cells acquire epigenetic hallmarks of human cancer during immortalization
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE39034 | GEO | 2012/11/29
SECONDARY ACCESSION(S): PRJNA169641
REPOSITORIES: GEO
Similar Datasets
Project description:Progression to malignancy requires cells to overcome senescence and switch to an immortal phenotype. Thus, exploring the genetic and epigenetic changes that occur during senescence/immortalization may help elucidate crucial events that lead to cell transformation. In the present study, we have globally profiled DNA methylation in relation to gene expression in primary, senescent and immortalized mouse embryonic fibroblasts. Primary, senescent and immortalized mouse fibroblasts obtained from three independent embryos. Compare immortalized versus primary and senescent versus primary cells.
2012-11-29 | E-GEOD-39034 | biostudies-arrayexpress
Project description:Human papillomavirus (HPV) induced immortalization of human foreskin keratinocytes (HFK) is a two-step process, including 1) the bypass of replicative senescence and acquisition of an extended lifespan, and 2) the outgrowth of immortal cells. Our previous study showed that the immortalization capacity of HPV is type dependent, as reflected by the presence or absence of a crisis period before reaching immortality. In the present study we determined how the HPV-type specific immortalization capacity relates to DNA damage induction and overall genomic instability. Early passage HFKs transduced with HPV types 16, 18, 31, 33, 35, 45, 51, 59, 66 and 70 showed an increased number of double strand DNA breaks compared to controls, without significant differences between the various HPV-types. However, immortal descendants of HPV-transduced HFKs that underwent a crisis period (HPV45-, 51-, 59-, 66- and 70-transduced HFKs) showed significantly more chromosomal aberrations compared to those without a crisis period (HPV16-, 18-, 31-, and 35-transduced HFKs) (p<0.01). In particular, regions on chromosome 5p, 8, and 9q were significantly more frequently altered in cells with crisis. Interestingly, the hTERT locus at 5p was exclusively gained in cell lines with crisis. Chromothripsis was detected in one of the HPV16-immortalized cell lines in which multiple rearrangements within chromosome 8 resulted in a gain of c-MYC. In conclusion, the present study shows that upon HPV-induced immortalization, the number of chromosomal aberrations is inversely related to the immortalization capacity of the virus type. This suggests that hrHPV types with reduced immortalization capacity in vitro, as reflected by a crisis period, require more genetic host cell aberrations to trigger immortalization. DNA copy number analysis of human keratinocytes transformed by high-risk HPV
2016-08-01 | E-GEOD-72063 | biostudies-arrayexpress
Project description:Cellular senescence forms a barrier that inhibits the acquisition of an immortal phenotype, a critical feature in tumorigenesis. The inactivation of multiple pathways that positively regulate senescence are required for immortalization. To identify these pathways in an unbiased manner, we performed DNA microarray analyses to assess the expression of 20,000 genes in human prostate epithelial cells (HPECs) passaged to senescence. These gene expression patterns were then compared with those of HPECs immortalized with the human Papillomavirus 16 E7 oncoprotein. Senescent cells display gene expression patterns that reflect their nonproliferative, differentiated phenotype and express secretory proteases and extracellular matrix components. A comparison of genes transcriptionally up-regulated in senescence to those in which expression is significantly down-regulated in immortalized HPECs identified three genes: the chemokine BRAK, DOC1, and a member of the insulin-like growth factor axis, IGFBP-3. Expression of these genes is found to be uniformly lost in human prostate cancer cell lines and xenografts, and previously, their inactivation was documented in tumor samples. Thus, these genes may function in novel pathways that regulate senescence and are inactivated during immortalization. These changes may be critical not only in allowing cells to bypass senescence in vitro but in the progression of prostate cancer in vivo.
2013-01-30 | E-SMDB-6 | biostudies-arrayexpress
Project description:Human papillomavirus (HPV) induced immortalization of human foreskin keratinocytes (HFK) is a two-step process, including 1) the bypass of replicative senescence and acquisition of an extended lifespan, and 2) the outgrowth of immortal cells. Our previous study showed that the immortalization capacity of HPV is type dependent, as reflected by the presence or absence of a crisis period before reaching immortality. In the present study we determined how the HPV-type specific immortalization capacity relates to DNA damage induction and overall genomic instability. Early passage HFKs transduced with HPV types 16, 18, 31, 33, 35, 45, 51, 59, 66 and 70 showed an increased number of double strand DNA breaks compared to controls, without significant differences between the various HPV-types. However, immortal descendants of HPV-transduced HFKs that underwent a crisis period (HPV45-, 51-, 59-, 66- and 70-transduced HFKs) showed significantly more chromosomal aberrations compared to those without a crisis period (HPV16-, 18-, 31-, and 35-transduced HFKs) (p<0.01). In particular, regions on chromosome 5p, 8, and 9q were significantly more frequently altered in cells with crisis. Interestingly, the hTERT locus at 5p was exclusively gained in cell lines with crisis. Chromothripsis was detected in one of the HPV16-immortalized cell lines in which multiple rearrangements within chromosome 8 resulted in a gain of c-MYC. In conclusion, the present study shows that upon HPV-induced immortalization, the number of chromosomal aberrations is inversely related to the immortalization capacity of the virus type. This suggests that hrHPV types with reduced immortalization capacity in vitro, as reflected by a crisis period, require more genetic host cell aberrations to trigger immortalization.
2016-08-01 | GSE72063 | GEO
Project description:Cellular senescence forms a barrier that inhibits the acquisition of an immortal phenotype, a critical feature in tumorigenesis. The inactivation of multiple pathways that positively regulate senescence are required for immortalization. To identify these pathways in an unbiased manner, we performed DNA microarray analyses to assess the expression of 20,000 genes in human prostate epithelial cells (HPECs) passaged to senescence. These gene expression patterns were then compared with those of HPECs immortalized with the human Papillomavirus 16 E7 oncoprotein. Senescent cells display gene expression patterns that reflect their nonproliferative, differentiated phenotype and express secretory proteases and extracellular matrix components. A comparison of genes transcriptionally up-regulated in senescence to those in which expression is significantly down-regulated in immortalized HPECs identified three genes: the chemokine BRAK, DOC1, and a member of the insulin-like growth factor axis, IGFBP-3. Expression of these genes is found to be uniformly lost in human prostate cancer cell lines and xenografts, and previously, their inactivation was documented in tumor samples. Thus, these genes may function in novel pathways that regulate senescence and are inactivated during immortalization. These changes may be critical not only in allowing cells to bypass senescence in vitro but in the progression of prostate cancer in vivo. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Computed
2005-10-18 | E-GEOD-3460 | biostudies-arrayexpress
Project description:Cellular senescence is a tumor suppressor mechanism, and immortalization facilitates neoplastic transformation. Both mechanisms may be highly relevant to hepatocellular carcinoma (HCC) development and its molecular heterogeneity. Cellular senescence appears to play a major role in liver diseases. Chronic liver diseases are associated with progressive telomere shortening leading senescence that is observed highly in cirrhosis, but also in some HCC. We previously described the generation of immortal and senescence-programmed clones from HCC-derived Huh7 cell line. We used microarrays to detail the global programme of gene expression profiles of immortal and senescent-programmed clones.
2013-05-23 | GSE17546 | GEO
Project description: Not available
| S-EPMC3592471 | biostudies-literature
Project description:Cellular senescence forms a barrier that inhibits the acquisition of an immortal phenotype, a critical feature in tumorigenesis. The inactivation of multiple pathways that positively regulate senescence are required for immortalization. To identify these pathways in an unbiased manner, we performed DNA microarray analyses to assess the expression of 20,000 genes in human prostate epithelial cells (HPECs) passaged to senescence. These gene expression patterns were then compared with those of HPECs immortalized with the human Papillomavirus 16 E7 oncoprotein. Senescent cells display gene expression patterns that reflect their nonproliferative, differentiated phenotype and express secretory proteases and extracellular matrix components. A comparison of genes transcriptionally up-regulated in senescence to those in which expression is significantly down-regulated in immortalized HPECs identified three genes: the chemokine BRAK, DOC1, and a member of the insulin-like growth factor axis, IGFBP-3. Expression of these genes is found to be uniformly lost in human prostate cancer cell lines and xenografts, and previously, their inactivation was documented in tumor samples. Thus, these genes may function in novel pathways that regulate senescence and are inactivated during immortalization. These changes may be critical not only in allowing cells to bypass senescence in vitro but in the progression of prostate cancer in vivo. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set
2005-10-18 | GSE3460 | GEO
Project description:There is a paradigm that cancer cells are immortal, which indicates that they have an ability to bypass cellular senescence. This is often linked with an expression of telomerase which restores the telomeric DNA. Cellular senescence may be induced in cancer cells by their exposure to clinically relevant doses of ionizing radiation (radiotherapy) and chemotherapy. It means that even though cancer cells avoided senescence in the course of their immortalization, they preserved intact molecular effectory pathways leading to senescence under some therapy-related conditions. Interestingly, it has repeatedly been described that tumors from patients who had no received any form of therapy also contain a fraction of cells bearing morphological and biochemical signature of senescence. Taking this into account, the goal of our project was to examine the presence of spontaneously senescent ovarian cancer cells in vivo and in vitro, and to describe molecular mechanisms underlying this phenomenon.
2019-05-24 | GSE131715 | GEO
Project description:- Gene expression changes linked to two step immortalization of human mammary epithelial cells (HMEC). - A lincRNA, MORT, associated with the mortal state, was identified - MORT is silenced by DNA methylation in immortal mammary epithelial cells 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 two 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 four individuals. 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 down-regulation 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.
2015-10-05 | GSE72353 | GEO