Project description:In this study, breast cancer MCF-7 cells were cultured under 0.5% oxygen for 24 h followed by 24 h of reoxygenation. Cells was harvested at 0, 1, 12, and 24 h during reoxygenation, and examined the miRNA profile by Nanostring nCounter. Forty-three miRNAs had dramatic changes as compared with 0 h upon reoxygenation, with 63% (n=27) of the miRNAs up-regulated upon reoxygenation. Among these miRNAs, miR-769-3p, which was down-regulated in MCF-7 upon reoxygenation, was chosen for further investigation. The hypothesis was that the down-regulation of NDRG1 upon reoxygenation was regulated by miRNAs. To examine wether miRNAs regulate NDRG1 under 0.5% O2 concentrations, the miRNA expression profiles of MCF-7 cells under reoxygenation were examined. Cells were harvested at 0 (hypoxia control), 1, 12, and 24 h upon reoxygenation. Each profile was done in triplicate. The genomic profile of miRNAs was measured using NanoString nCounter® miRNA Expression Assays.
Project description:Pre-operative progesterone intervention has been shown to confer a survival benefit to breast cancer patients independent of their progesterone receptor (PR) status, raising a question about how progesterone affects the outcome of PR-negative cells. Here, we identify up-regulation of a Serum- and glucocorticoid-regulated kinase gene, SGK1 and an N-Myc Downstream Regulated Gene 1, NDRG1, along with down-regulation of miR-29a and miR-101-1 targeting 3’UTR region of SGK1, to differential extents in a PR dependent manner in breast cancer cells. We further demonstrate a novel dual-phase transcriptional and post-transcriptional regulation of SGK1 in response to progesterone leading to up-regulation of a tumor metastasis suppressor gene, NDRG1, mediated by a set of AP-1 network genes. The NDRG1 further inactivates a set of kinases impeding the invasion and migration of breast cancer cells. In summary, we propose a model for the mode of action of progesterone in breast cancer deciphering the molecular basis of a randomized clinical trial studying the effect of progesterone in breast cancer with a potential to improve the prognosis of breast cancer patients for receiving pre-operative progesterone treatment.
Project description:Host cells harbor various intrinsic mechanisms to restrict viral infections as a first line of antiviral defense. Viruses have evolved various countermeasures against these antiviral mechanisms. Here we show that N-Myc Downstream-Reguated Gene 1 (NDRG1) limits productive HCV infection by inhibiting viral assembly. Interestingly, HCV infection down-regulates NDRG1 protein and mRNA expression. Loss of NDRG1 increases the size and number of lipid droplets, which are the sites of HCV assembly. HCV suppresses NDRG1 expression by up-regulating MYC, which directly inhibits the transcription of NDRG1. Up-regulation of MYC also leads to reduced expression of NDRG1-specific kinase SGK1, resulting in markedly diminished phosphorylation of NDRG1. Knockdown of MYC during HCV infection rescues NDRG1 expression and phosphorylation, suggesting that MYC regulates NDRG1 at both transcriptional and post-translational levels. Overall, our results suggest that NDRG1 restricts HCV assembly by limiting lipid droplet formation. HCV counteracts this intrinsic antiviral mechanism by down-regulating NDRG1 via a MYC-dependent mechanism.
Project description:In this study, breast cancer MCF-7 cells were cultured under 0.5% oxygen for 24 h followed by 24 h of reoxygenation. Cells was harvested at 0, 1, 12, and 24 h during reoxygenation, and examined the miRNA profile by Nanostring nCounter. Forty-three miRNAs had dramatic changes as compared with 0 h upon reoxygenation, with 63% (n=27) of the miRNAs up-regulated upon reoxygenation. Among these miRNAs, miR-769-3p, which was down-regulated in MCF-7 upon reoxygenation, was chosen for further investigation.
Project description:To investigate the transcriptional response of tumor adaptation to reoxygenation, breast cancer cells MCF-7 was cultured under 0.5% of hypoxia for 24h followed by 24h of reoxygenation in normoxia. Cells were harvested respectively at 0, 1, 4, 8, 12, and 24h during reoxygenation. Total RNA obtained from human breast cancer cell line MCF-7 were collected respectively at 0, 1, 4, 8, 12 and 24 hours after reoxygenation.
Project description:To investigate the cooperative function HJURP/YAP1/NDRG1 in the regulation of progression in triple negative breast cancer, we established MDA-MB-231 cell lines in which each target gene has been knocked down by shRNA. We then performed gene expression profiling analysis using data obtained from RNA-seq of 2 different cells.