Project description:Snail is a zinc-finger transcription factor best known for its ability to down-regulate E-cadherin. Its established significance in embryology and organogenesis has been expanded to include a role in the tumor progression of a number of human cancers. In addition to E-cadherin, it has more recently been associated with the down-regulation and up-regulation of a number of other genes that affect important malignant phenotypes. After establishing the presence of up-regulated Snail in human non-small cell lung cancer specimens, we used microarrays to detail the global programme of gene expression in non-small cell lung cancer cell lines stably transduced to over-express Snail as compared to vector control cell lines. Non-small cell lung cancer cell lines (H441, H292, H1437) were stably transduced with a retroviral vector to over-express Snail. Elevated Snail and a corresponding down-regulation of E-cadherin was verified in the Snail over-expressing cell lines as compared to vector control cell lines by Western analysis. RNA extraction was performed and samples submitted to the UCLA Clinical Microarray Core for hybridization to Affymetrix arrays.
Project description:Snail is a zinc-finger transcription factor best known for its ability to down-regulate E-cadherin. Its established significance in embryology and organogenesis has been expanded to include a role in the tumor progression of a number of human cancers. In addition to E-cadherin, it has more recently been associated with the down-regulation and up-regulation of a number of other genes that affect important malignant phenotypes. After establishing the presence of up-regulated Snail in human non-small cell lung cancer specimens, we used microarrays to detail the global programme of gene expression in non-small cell lung cancer cell lines stably transduced to over-express Snail as compared to vector control cell lines.
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: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. Four lung cancer cell lines (H292, H358, H441, H1437) with stable overexpression of the human SNAI1 gene and vector expressing controls were collected at equal confluency with the miRNeasy Mini kit (Qiagen). One microgram of total RNA was labeled using miRCURY LNA™ microRNA Array Power Labeling kit by the UCLA Clinical Microarray Core. The labeled miRNAs were hybridized to Exiqon miRCURY LNA microRNA Array-6th Generation according to the manufacturer’s instructions. This array includes 927/648/351 human/mouse/rat miRNAs as well as 438 miRPlus miRNAs. The miRNA array slides were scanned using Axon GenePix 4000B scanner (Axon Instruments, Foster City, CA) and processed by using the GenePix Pro 6.0 software (Axon Instruments). The raw data were normalized by using a combination of housekeeping miRNA, spike-in miRNA and invariant endogenous miRNAs.
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: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:Snail, a family of transcriptional repressors implicated in cell movement, has been correlated with tumour invasivity. The Plasminogen Activation system (PAs), including urokinase (uPA), its receptor (uPAR), and its inhibitor (PAI-1), also plays a key role in cancer invasion and metastasis, either through proteolytic degradation or by non proteolytic modulation of cell adhesion and migration. Thus, Snail and PAs both influence those processes and are over-expressed in cancers. In this study we aimed to determine first whether Snail activity is correlated with PAs components expression and second how this correlation can influence tumoral cell migration. Keywords: Tumoral migration Comparison the invasive breast cancer cell-line MDA-MB-231 expressing Snail (MDA-Neo) with its derived clone expressing a dominant negative form of Snail (Snail-DN). Expression of PAs mRNAs was performed by cDNA microarrays and real time quantitative RT-PCR. Wound healing assay was used to determine cell migration. PAI-1â??s distribution was assessed by immunostaining.
Project description:Epithelial-mesenchymal transition (EMT) is in the highlights as a significant role in tumor progression and invasion. Snail was known as the one of regulators of EMT in various malignant tumors. The aim of this study was to investigate the effect of Snail on invasiveness/migratory ability of gastric cancer cell lines and clinicopathological and prognostic significance of Snail over-expression using immunohistochemistry in tissue microarray of 314 gastric adenocarcinomas (GC). Differential gene expression in Snail over-expressed GC was investigated using cDNA microarray analysis. Silencing of Snail by ShRNA induced decreased of invasion, migration of gastric cancer cell lines. In contrast, over-expression of Snail induced increased invasiveness and migratory ability of gastric cancer cell lines in accordance increase of VEGF and MMP11. Furthermore, the over-expression of Snail (?75% nuclear staining of Snail) was significantly associated with tumor progression (p<0.0001), lymph node metastases (p=0.002), lymphovascular invasion (p=0.002), and perineural invasion (p=0.002) in 314 GC patient. Snail over-expression was also associated with poor prognosis (shorter survival) in GC patients (p=0.023). cDNA microarray revealed 213 differential expressed genes in Snail over-expressed GC tissues, including genes related to metastasis, invasion. Based on above results, it was suggested that Snail plays a significant role in invasiveness/migratory ability of GCs. In addition, Snail might be used to predictive biomarker for evaluation of prognosis or aggressiveness in GCs. 48 primary gastric adenocarcinoma fresh frozen tissues were used for microarray. All the tissues were obtained after curative resection after pathologic confirm at Pusan National University Hospital (PNUH, Busan, Korea) and Cheonnam University Hospital (CNUH, Cheonnam, Korea). Microarray experiment and data analysis were done at Cancer research institute, PNUH, Busan, Korea.