Project description:ChIP-seq analysis of SNAIL binding sites in RH30 cells was performed to discover novel SNAIL binding sites in rhabdmyosarcoma cells.
Project description:Pachytene piRNAs are PIWI-interacting small RNAs abundantly expressed in pachytene spermatocytes and spermatids in adult mouse testes. Both MIWI and MILI-bound pachytene piRNAs have been found enriched in round spermatids. Miwi-null male mice are sterile due to spermiogenic arrest. In C. elegans, sperm-borne piRNAs appear to have an epigenetic role during fertilization and development because progeny of offspring derived from piRNA-deficient sperm display a progressive fertility loss after several generations. In mice, it remains unknown whether MIWI-bound pachytene piRNA-deficient round spermatids can produce offspring, and whether the progeny of offspring derived from MIWI-bound pachytene piRNA-deficient round spermatids also exhibit transgenerational loss of fertility. Here, we report that Miwi KO round spermatids could fertilize both wild type (WT) and Miwi KO oocytes through round spermatid microinjection (ROSI), and produce healthy and fertile offspring despite the aberrant pachytene piRNA profiles in those Miwi KO spermatids. Progeny of ROSI-derived heterozygotes, both male and female, displayed normal fertility for at least three generations when bred with either WT or Miwi KO females. Our data indicate that aberrant MIWI-bound pachytene piRNAs profiles in spermatids do not affect fertilization, early embryonic development, or fertility of the offspring, suggesting a normal pachytene piRNAs profile is not required for paternal transgenerational epigenetic inheritance in mice. Method: Round spermatids were purified from WT and Miwi KO adult testes using a mini-STA-PUT method[Methods Enzymol 1993; 225:84-113.],the purity of round spermatids was >90% based on our previous report[ J Biol Chem 2012; 287:25173-25190.]. Small RNA was isolated from round spermatids using the mirVana RNA isolation kit (Ambion) according to the manufacturer’s instructions. RNA quality and quantity were assessed using the Agilent 2100 Bioanalyzer. Small RNA-Seq was performed on an Ion Proton sequencer (Life Technologies). Libraries were prepared using the Ion Total RNA-Seq Kit v2 (Invitrogen) with biological triplicates for WT and Miwi KO samples. Resutls:Our data indicate that aberrant MIWI-bound pachytene piRNAs profiles in spermatids do not affect fertilization, early embryonic development, or fertility of the offspring, suggesting a normal pachytene piRNAs profile is not required for paternal transgenerational epigenetic inheritance in mice.
Project description:In skeletal myogenesis, the transcription factor MyoD activates distinct transcriptional programs in progenitors compared to terminally differentiated cells. Using ChIP-seq and gene expression analyses, we show that in primary myoblasts, Snail-HDAC1/2 repressive complex bind and exclude MyoD from its targets. Notably, Snail binds E-box motifs that are G/C-rich in their central dinucleotides, and such sites are almost exclusively associated with genes expressed during differentiation. By contrast, Snail does not bind the A/T-rich E-boxes associated with MyoD targets in myoblasts. Thus, Snai1-HDAC1/2 prevents MyoD occupancy on differentiation-specific regulatory elements and the change from Snail- to MyoD-binding often results in enhancer switching during differentiation. Furthermore, we show that a regulatory network involving Myogenic Regulatory Factors (MRFs), Snail/2, miR-30a and miR-206 acts as a molecular switch that controls entry into myogenic differentiation. Together, these results reveal a regulatory paradigm that directs distinct gene expression programs in progenitors versus terminally differentiated cells. Genome wide binding sites of various transcription factors and chromatin modifiers in muscle cells
Project description:The transcription factor Snail is known as an EMT regulator to promote cancer metastasis. Identification Snail-regulated miRNAs helps to uncover mechanisms governing CRC metastasis
Project description:We report a series of ChIP-Seq results in HeLa cells. Briefly, we performed ChIP-Seq experiments with antibodies specific for Snail, MTA1, and PRMT5 in HeLa cells. We found that Snail, MTA1, and PRMT5 had similar binding motifs. This study gave us a new understanding of the role of Snail in chromatin status and gene transcription.
Project description:Cancer stem cells (CSCs) are proposed to be responsible for metastatic dissemination and clinical relapse in a variety of cancers. Analogies between CSCs and normal tissue stem cells (SC) has led to the notion that CSCs often co-opt the normal SC program of their tissue-of-origin. The cell-biological program termed epithelial-mesenchymal transition (EMT) has been found to encourage entrance of normal and neoplastic mammary cells into the corresponding SC states. Using genetically engineered knock-in reporter mouse lines, we demonstrate that in the murine mammary lineage, the paralogous EMT-inducing transcription factors Snail and Slug, are selectively exploited by CSCs and normal SCs respectively. Slug, when expressed at physiological levels, only activates a partial EMT program and is dispensable in CSCs. In contrast, Snail drives a far more complete transition into the mesenchymal state and controls both tumor-initiation and metastatic dissemination. Consistent with their functional distinctions, Snail controls far more target genes than Slug, and their distinct functions are determined by their divergent N-terminal domains. Our findings underscore fundamental distinctions between the SC program operating in normal and neoplastic SCs, and hint for potential avenues of selective therapeutic elimination of breast CSCs. We sought to understand differential ability to activate the EMT program in breast cancer cells by transcription factors Snail and Slug. Hence, we mapped genome-wide Snail and Slug binding sites in murine MMTV-PyMT breast cancer cell lines that express high level of Snail or high level of Slug respectively. Specifically, we performed Snail ChIP seq in the mesenchymal pBl.3G cells, and Slug ChIP-seq in the epithelial pBl.1G cells.
Project description:The significance of epithelial-to-mesenchymal transition (EMT)-inducing transcription factors in the onset of non-small cell lung cancer has not been resolved. Here, we report increased Snail expression in pulmonary premalignant lesions relative to histologically normal-appearing pulmonary epithelium. Utilizing immortalized human pulmonary epithelial cells and isogenic derivatives, we document Snail-dependent anchorage-independent growth of the epithelial cells in vitro, as well as transformation, primary tumor growth, and metastatic behavior in vivo. Epithelial splicing regulatory protein 1 (ESRP1) tumor suppressor silencing was a requirement for Snail-driven transformation in vivo, and we identified ESRP1 loss in Snail-expressing pulmonary premalignant lesions in situ. Snail drives these and other carcinogenic signaling programs in an ALDH+CD44+CD24- pulmonary stem cell subset in which ESRP1 and stemness-repressing micro-RNAs are inhibited.
Project description:Analysis of four lung cancer cell lines transfected with a vector expressing the transcriptional repressor Snail versus a vector control. Aberrant Snail expression is known to induce an EMT program in lung cancers.
Project description:Using human colon cancer DLD-1 cells, we engineered a cell line with a doxycycline-inducible single-copy of Snail and compared it to an existing EMT models in DLD-1 where Snail was introduced by episome transfection. Induction of the single-copy line (Snail-lo) with doxycycline increased Snail expression to a level similar to that observed in cancer cell lines spontaneously expressing Snail and results in partial EMT. In comparison, higher levels of overexpression arising from introduction of episomal-Snail (Snail-hi), results in complete EMT.