Project description:Anchorage of tissue cells to their physical environment is an obligate requirement for survival that is lost in mature hematopoietic and in transformed epithelial cells. Here we find that a lymphocyte lineage-restricted transcription factor, Aiolos, is frequently expressed in lung cancers and predicts markedly reduced patient survival. Aiolos decreases expression of a large set of adhesion-related genes, disrupting cell-cell and cell-matrix interactions. Aiolos also reconfigures chromatin structure within the SHC1 gene, causing isoform-specific silencing of the anchorage reporter p66Shc and blocking anoikis in vitro and in vivo. In lung cancer tissues and single cells, p66Shc expression inversely correlates with that of Aiolos. Together, these findings suggest that Aiolos functions as an epigenetic driver of lymphocyte mimicry in metastatic epithelial cancers.
Project description:Analysis of transcriptional profiling change comparing A549 cells expressing control empty vector and A549 cells expressing Aiolos. Results provide insight into molecular mechanisms underlying functional consequence of ectopic expression of Aiolos in solid cancer cells. Two-condition experiment, A549-empty vs. A549-Aiolos cells. Biological replicates: 3 control, 3 transfected, independently grown and harvested. One replicate per array.
Project description:Cervical cancer and a subset of anogenital and head-and-neck carcinomas are caused by persistent infection with high-risk types of the human papillomavirus (hrHPV). Early stages of hrHPV-induced carcinogenesis can be faithfully mimicked in vitro. A major hallmark of hrHPV-transformed cells is their ability to grow anchorage independently, an oncogenic trait known to depend on inactivation of tumour suppressor genes. This study used an in vitro model of hrHPV-induced transformation to delineate in a longitudinal manner to what extent DNA methylation-mediated silencing of tumour suppressive microRNAs (miRNAs) contributed to hrHPV-induced anchorage independence. Genome-wide miRNA expression profiles were yielded from anchorage dependent (n=11) and independent passages (n=19) of 4 hrHPV-immortalised keratinocyte cell lines with and without demethylating treatment (DAC). Unsupervised clustering analysis showed that overall miRNA expression patterns discriminated between anchorage dependent and independent cells. Ten miRNA genes potentially silenced by methylation were selected and validated by bisulfite sequencing and methylation-specific PCR. Hsa-mir-129-2, -137, -935, -3663, -3665, and -4281 showed increased methylation in both HPV-transformed keratinocytes and cervical cancer cell lines compared to primary keratinocytes. Mature miRNAs derived from hsa-mir-129-2, -137, -3663, and -3665 decreased anchorage independence in cervical cancer cell lines. Finally, significantly increased methylation of hsa-mir-129-2, -935, -3663, -3665, and -4281 was observed in cervical (pre)cancerous lesions, underlining the clinical relevance of our findings. In conclusion, methylation-mediated silencing of tumour suppressive miRNAs contributes to the acquisition of anchorage independence, supporting the importance of miRNAs during early stages of carcinogenesis and underlining their potential as both disease markers and therapeutic targets.
Project description:Cervical cancer and a subset of anogenital and head-and-neck carcinomas are caused by persistent infection with high-risk types of the human papillomavirus (hrHPV). Early stages of hrHPV-induced carcinogenesis can be faithfully mimicked in vitro. A major hallmark of hrHPV-transformed cells is their ability to grow anchorage independently, an oncogenic trait known to depend on inactivation of tumour suppressor genes. This study used an in vitro model of hrHPV-induced transformation to delineate in a longitudinal manner to what extent DNA methylation-mediated silencing of tumour suppressive microRNAs (miRNAs) contributed to hrHPV-induced anchorage independence. Genome-wide miRNA expression profiles were yielded from anchorage dependent (n=11) and independent passages (n=19) of 4 hrHPV-immortalised keratinocyte cell lines with and without demethylating treatment (DAC). Unsupervised clustering analysis showed that overall miRNA expression patterns discriminated between anchorage dependent and independent cells. Ten miRNA genes potentially silenced by methylation were selected and validated by bisulfite sequencing and methylation-specific PCR. Hsa-mir-129-2, -137, -935, -3663, -3665, and -4281 showed increased methylation in both HPV-transformed keratinocytes and cervical cancer cell lines compared to primary keratinocytes. Mature miRNAs derived from hsa-mir-129-2, -137, -3663, and -3665 decreased anchorage independence in cervical cancer cell lines. Finally, significantly increased methylation of hsa-mir-129-2, -935, -3663, -3665, and -4281 was observed in cervical (pre)cancerous lesions, underlining the clinical relevance of our findings. In conclusion, methylation-mediated silencing of tumour suppressive miRNAs contributes to the acquisition of anchorage independence, supporting the importance of miRNAs during early stages of carcinogenesis and underlining their potential as both disease markers and therapeutic targets.