Project description:The SNAI1 and SNAI2 embryonic genes are reactivated in numerous cancer types, including carcinomas. They promote cancer cell dissemination by inducing an epithelial-to-mesenchymal transition (EMT) and by protecting cells from anoikis. We now have demonstrated that the sequentially related SNAI3 gene is aberrantly reactivated in human breast carcinomas. To compare the functional properties of the three SNAIL family members, the transcription factors were ectopically expressed in immortalized mammary epithelial cells.
Project description:The SNAI1 and SNAI2 embryonic genes are reactivated in numerous cancer types, including carcinomas. They promote cancer cell dissemination by inducing an epithelial-to-mesenchymal transition (EMT) and by protecting cells from anoikis. We now have demonstrated that the sequentially related SNAI3 gene is aberrantly reactivated in human breast carcinomas. To compare the functional properties of the three SNAIL family members, the transcription factors were ectopically expressed in immortalized mammary epithelial cells. Immortalized human mammary epithelial cells (HMEC-hTERT cells) or MCF10A cells were infected with SNAIL retroviral expression constructs. The gene expression profiles of the resulting cell lines, cultured in standard conditions or after plating them 24h in low-adherent (LA) conditions, were performed.
Project description:The oncogene SNAI2 is known to be a master transcription factor that regulates a broad range of cellular processes, including epithelial-mesenchymal transition (EMT). As a transcription factor, there is no doubt that SNAI1/2 could directly regulate the expression of thousands of genes, including lncRNAs. In this study, we took SNAI1/2 as a breakthrough point to screen and identify lncRNAs regulated by SNAI2 in GC. Our data showed that overexpression of SNAI2 caused a 1.5-fold change in the expression of about 654 lncRNAs (|Log2FC| >0.5), and a 2-fold change in the expression of about 123 lncRNAs (|Log2FC| >1).
Project description:The propensity of cancer cells to transition between epithelial and mesenchymal phenotypic states is considered to be critical in metastatic processes, cancer progression, and treatment resistance. To investigate a transient epithelial-mesenchymal transition (EMT) in prostate adenocarcinoma, LNCaP cells with inducible and reversible expression of SNAI1 or SNAI2 were generated. Cells were treated with doxycycline to induce a SNAI1- or SNAI2-mediated EMT for 5 days and then subsequently removed for 3, 5, and 20 days to allow for MET. LNCaP-iGFP cells were also generated for control purposes and were subjected to the same treatment regime.
Project description:This SuperSeries is composed of the following subset Series: GSE24811: Time Series of Mouse skeletal muscle cell differentiation GSE24852: ChIP-Seq of MyoD, Myf5, Snai1, HDAC1, HDAC2, E47 and empty vector controls in mouse skeletal myoblasts or myotubes GSE38236: RNA-Seq of si-Snai1, si-Snai2, si-Snai1/2 and si-Scrambled treated myoblasts Refer to individual Series
Project description:Promoter-proximal RNA polymerase II (Pol II) pausing is implicated in the regulation of gene transcription. However, the mechanisms of pausing including its dynamics during transcriptional responses remain to be fully understood. We performed global analysis of short capped RNAs and Pol II Chromatin Immunoprecipitation sequencing in MCF-7 breast cancer cells to map Pol II pausing across the genome, and used permanganate footprinting to specifically follow pausing during transcriptional activation of several genes involved in the Epithelial to Mesenchymal Transition (EMT). We find that the gene for EMT master regulator Snail (SNAI1), but not Slug (SNAI2), shows evidence of Pol II pausing before activation. Transcriptional activation of the paused SNAI1 gene is accompanied by a further increase in Pol II pausing signal whereas activation of non-paused SNAI2 gene results in the acquisition of a typical pausing signature. The increase in pausing signal reflects increased transcription initiation without changes in Pol II pausing. Activation of the heat shock HSP70 gene involves pausing release that speeds up Pol II turnover, but does not change pausing location. We suggest that Pol II pausing is retained during transcriptional activation and can further undergo regulated release in a signal-specific manner.
Project description:Promoter-proximal RNA polymerase II (Pol II) pausing is implicated in the regulation of gene transcription. However, the mechanisms of pausing including its dynamics during transcriptional responses remain to be fully understood. We performed global analysis of short capped RNAs and Pol II Chromatin Immunoprecipitation sequencing in MCF-7 breast cancer cells to map Pol II pausing across the genome, and used permanganate footprinting to specifically follow pausing during transcriptional activation of several genes involved in the Epithelial to Mesenchymal Transition (EMT). We find that the gene for EMT master regulator Snail (SNAI1), but not Slug (SNAI2), shows evidence of Pol II pausing before activation. Transcriptional activation of the paused SNAI1 gene is accompanied by a further increase in Pol II pausing signal whereas activation of non-paused SNAI2 gene results in the acquisition of a typical pausing signature. The increase in pausing signal reflects increased transcription initiation without changes in Pol II pausing. Activation of the heat shock HSP70 gene involves pausing release that speeds up Pol II turnover, but does not change pausing location. We suggest that Pol II pausing is retained during transcriptional activation and can further undergo regulated release in a signal-specific manner. Untreated MCF-7 cells were analyzed for the distribution of Pol II using ChIP-sequencing with Anti-Pol II N-20 antibody (two independent biological replicates, A, B), and for the distribution of paused RNA polymerase II by sequencing of short capped RNAs (scRNAs) prepared from nuclei (three independent biological replicates, 1-3). All samples were sequenced on a MiSeq instrument in paired-end format
Project description:The core subunit of the COMPASS-like complex, WD Repeat Domain 5 (WDR5) has a prominent role in reprogramming and Epithelial-to-Mesenchymal transition (EMT) in different tumor types. Our evidences support a model in which WDR5 is prominent for EMT and metastasis dissemination in breast cancer patient-derived xenografts and cell lines. Moreover, WDR5 silencing abrogates TGFB pathway activation and reverts mesenchymal into epithelial phenotype, by inhibiting transcription of main master regulators of EMT (CDH2, TWIST1, SNAI1, SNAI2 and ZEB1). Our data suggest that WDR5 inhibition may be a successful approach to prevent progression of metastatic BC.
Project description:The core subunit of the COMPASS-like complex, WD Repeat Domain 5 (WDR5) has a prominent role in reprogramming and Epithelial-to-Mesenchymal transition (EMT) in different tumor types. Our evidences support a model in which WDR5 is prominent for EMT and metastasis dissemination in breast cancer patient-derived xenografts and cell lines. Moreover, WDR5 silencing abrogates TGFB pathway activation and reverts mesenchymal into epithelial phenotype, by inhibiting transcription of main master regulators of EMT (CDH2, TWIST1, SNAI1, SNAI2 and ZEB1). Our data suggest that WDR5 inhibition may be a successful approach to prevent progression of metastatic BC.
Project description:The core subunit of the COMPASS-like complex, WD Repeat Domain 5 (WDR5) has a prominent role in reprogramming and Epithelial-to-Mesenchymal transition (EMT) in different tumor types. Our evidences support a model in which WDR5 is prominent for EMT and metastasis dissemination in breast cancer patient-derived xenografts and cell lines. Moreover, WDR5 silencing abrogates TGFB pathway activation and reverts mesenchymal into epithelial phenotype, by inhibiting transcription of main master regulators of EMT (CDH2, TWIST1, SNAI1, SNAI2 and ZEB1). Our data suggest that WDR5 inhibition may be a successful approach to prevent progression of metastatic BC.