Project description:To screen the genes regulated by wt-Snail and non-acetylated Snail The successful development of cancer metastasis requires two major events: the reprogramming of cancer cells to increase their migration and tumor-initiation capabilities; and the remodeling of the tumor microenvironment to facilitate invasion and colonization of cancer cells. Epithelial-mesenchymal transition (EMT) is a crucial mechanism for reprogramming cancer cells to possess tumor initiation and migration capabilities1,2. However, the role of EMT in the interplay between tumor and host cells is largely unknown. The EMT regulator Snail is mainly known as a transcriptional repressor of the adhesion protein E-cadherin, whose repression is considered to be a key step in initiating metastasis3,4. We previously found that Snail can also act as an activator that induces the transcription of ERCC15 and IL86. Here we show that Snail is acetylated by CREB-binding protein (CBP) and that Snail and CBP co-occupy the promoters of target genes to activate transcription of the target genes. Furthermore, Snail activates the expression of a panel of cytokine genes, including TNFa (which forms a positive feedback loop with Snail to amplify the signal) and CCL2 and CCL5 (which facilitate the recruitment of macrophages by cancer cells). Our results demonstrate a novel function for Snail, providing new understanding of the recruitment of host cells to tumor sites during metastatic evolution. Establish stable transfectants of pCDH-Snail and pCDH-Snail2R in FaDu cells and analyze the mRNA expression level of by cDNA microarray. FaDu transfected with pCDH vector was used as a control experiment.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs. One-condition experment, gene expression of 3A6
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes