Project description:miRNAs exert various biological functions by targeting different cellular targets. Studying miR-146a functions in colon cancer cells helps to understand colorectal cancer (CRC) malignancy and progression. HT29 miR-146a-expressing cells and empty control cells were established for mining the gene expression profiles upon miR-146a expression.
Project description:miRNAs exert various biological functions by targeting different cellular targets. Studying miR-146a functions in colon cancer cells helps to understand colorectal cancer (CRC) malignancy and progression.
Project description:MiR-146a is an important regulator of innate inflammatory responses and is also implicated in cell death and survival. Here, we identified microglia as the main cellular source of miR-146a among mouse CNS resident cells. We further characterized the phenotype of miR-146a KO microglia cells during in vivo demyelination induced by cuprizone (CPZ) and found reduced number of CD11c+ microglia in the KO compared to WT mice. Microglia were also isolated from the brain, and the proteome was analyzed by liquid chromatography mass spectrometry.
Project description:Inflammatory bowel disease (IBD) is a multiple-genes-involved chronic disease and current available targeted drugs for IBD only deliver moderate efficacy. Whether there is a single gene that systematically regulates IBD is not yet known. Here we showed that the expression of miR-146a in colon was elevated in Dextran Sulfate Sodium Salt (DSS)-induced IBD mice and patients with IBD. DSS induced dramatic body weight loss and much more rectal bleeding, shorter colon length and colitis in miR-146a knock-out mice than wild type (WT) mice. The miR-146a mimics alleviated DSS-induced symptoms in both DSS-induced miR-146a-/- and WT mice. Further RNA sequencing illustrated that deficiency of miR-146a de-repressed majority of DSS-induced IBD-related genes which cover multiple genetic regulatory networks in IBD, and supplement of miR-146a mimics inhibited expression of many IBD-related genes. DOI 10.3389/fimmu.2024.1366319
Project description:Oncogenic mutations in BRAF and NRAS occur in 70% of melanomas. Here we identify a microRNA, miR-146a, that is highly upregulated by oncogenic BRAF and NRAS. Expression of miR-146a increases the ability of human melanoma cells to proliferate in culture and form tumors in mice, whereas knockdown of miR-146a has the opposite effects. We show these oncogenic activities are due to miR-146a targeting the NUMB mRNA, a repressor of Notch signaling. Previous studies have shown that pre-miR-146a contains a single nucleotide polymorphism (C>G rs2910164). We find that the ability of pre-miR-146a/G to activate Notch signaling and promote oncogenesis is substantially higher than that of pre-miR-146a/C. Analysis of melanoma cell lines and matched patient samples indicates that during melanoma progression pre-miR-146a/G is enriched relative to pre-miR-146a/C, resulting from a C-to-G somatic mutation in pre-miR-146a/C. Collectively, our results reveal a central role for miR-146a in the initiation and progression of melanoma.
Project description:We established stable miR-146a-5p overexpression T24 cells, then performed transcriptome profiling of miR-146a-5p overexpressing cells compared to control T24 cells to detect the molecular mechanisms of the miR-146a-5p’s effect on bladder cancer cells.
Project description:The Epstein Barr virus (EBV) encoded latent membrane protein-1 (LMP1) is a functional homologue of the tumor necrosis factor receptor family and contributes substantially to the oncogenic potential of EBV through activation of Nuclear Factor-kappaB (NF-kappaB). MicroRNAs (miRNAs) are a class of small RNA molecules that are involved in the regulation of cellular processes such as growth, development, and apoptosis, and have recently been linked to cancer phenotypes. Through miRNA microarray analysis, we demonstrate that LMP1 dysregulates the expression of several cellular miRNAs, including the most highly regulated of these, miR-146a. Quantitative RT-PCR analysis confirmed induced expression of miR-146a by LMP1. Analysis of miR-146a expression in EBV latency type III and type I cell lines revealed substantial expression of miR-146a in type III (which express LMP1) but not in type I cell lines. Reporter studies demonstrated that LMP1 induces miR-146a predominantly through two NF-kappaB binding sites in the miR-146a promoter and identified a role for an OCT-1 site in conferring basal and induced expression. Array analysis of cellular mRNAs expressed in Akata cells transduced with an miR-146a expressing retrovirus identified genes that are directly or indirectly regulated by miR-146a, including a group of interferon responsive genes that are inhibited by miR-146a. Since miR-146a is known to be induced by agents that activate the interferon response pathway (including LMP1), these results suggest that miR-146a functions in a negative feedback loop to modulate the intensity and/or duration of the interferon response. Keywords: microRNA expression modified by EBV encoded oncogene, LMP1
Project description:We have found expression of miR-146a up-regulated in gastric cancer. To identify new targets of miR-146a we profiled the transcriptome after miR-146a over-expression in the human gastric cancer cell line SNU638. SNU638 cells were transfected in triplicates with 50 nM miR-146a or control (siGlo) using Lipofectamine 2000. Total RNA was harvested 24 h after transfection using Trizol reagent. There are a total of six arrays included in this experiment, including three biological replicates of mRNA expression after miR-146a over-expression and three controls in SNU638 cells.