Project description:This study aimed to identify differential expressed genes before and after transfection with miR-192,miR-204 and siHOTTIP, using the HepG2 liver cancer cell line as a model.
Project description:Deficient DNA repair capacity is associated with genetic lesions accumulation and susceptibility to carcinogenesis. MicroRNAs (miRNAs) are small non-coding RNAs that regulate various cellular pathways including DNA repair. Here we hypothesized that the existence of HBV products may interfere with cellular nucleotide excision repair (NER) through microRNA-mediated gene regulation. We found that NER was impaired in HepG2.2.15 cells, a stable HBV-expressing cell line, compared with its parental cell line HepG2. Altered miRNA expression profile, in particular the significant upregulation of miR-192, was observed in HepG2.2.15 cells. Additionally, ERCC3 and ERCC4, two key factors implicated in NER, were identified as targets of miR-192 and over-expressing miR-192 significantly inhibited cellular NER. These results indicated that persistent HBV infection might trigger NER impairment in part through upregulation of miR-192, which suppressed the levels of ERCC3 and ERCC4. It provides new insight into the effect of chronic HBV infection on NER and genetic instability in cancer. A genome-wide miRNAs microarray was performed to identify differentially expressed miRNAs between HepG2.2.15, a stable HBV-expressing cell line, and its parental cell line HepG2.
Project description:Genome-wide expression analysis of MCF-10A and MCF-7 where miR-204 and miR-211 are overexpressed. The characteristics of differentially expressed genes in both cell lines derives the cells toward being oncogenic.
Project description:Cell cycle arrest in response to DNA damage is an important anti-tumorigenic mechanism. microRNAs (miRNAs) were shown recently to play key regulatory roles in cell cycle progression. For example, miR-34a is induced in response to p53 activation and mediates G1 arrest by down-regulating multiple cell cycle-related transcripts. Here we show that genotoxic stress promotes the p53-dependent up-regulation of the homologous miRNAs, miR -192 and miR-215. Like miR-34a, activation of miR-192/215 induces cell cycle arrest suggesting that multiple microRNA families operate in the p53 network. Furthermore, we define a downstream gene expression signature for miR-192/215 expression that includes a number of transcripts that regulate G1 and G2 checkpoints. Of these transcripts, 18 transcripts are direct targets of miR-192/215 and the observed cell cycle arrest likely results from a cooperative effect among the modulations of these genes by the miRNAs. Our results demonstrating a role for miR-192/215 in cell proliferation combined with recent observations that these miRNAs are under-expressed in primary cancers support the idea that miR-192 and miR-215 function as tumor-suppressors. Description: Transfection of siRNA luc, miR-192 or miR-215 into HCT116 Dicerex5, compared to mock-transfected cells, with mRNA expression profiled at 10h and 24h post-transfection. Species: Human Tissue: HCT116 Dicerex5 cell line (tissue of origin = human colorectal carcinoma); this cell line is hypomorphic for Dicer gene function. Dye-swap: no Negative control: siRNA luc Replicates per each timepoint: no
Project description:There is high need of novel diagnostic and prognostic tools for tumors of the digestive system, such as gastric cancer and cholangiocarcinoma. We employed Affymetrix profiling of 15 gastric tumor tissues and 5 normals to evaluate the levels of miR-204 target genes. We performed extensive in silico analysis to identify a minimal gene target signature which anti-correlated with the levels of miR-204 and validated all of the findings on publicly available databases. We employed transient transfection experiments, clonogenic assays and cell cycle profiling to evaluate the dependency of the target genes signature of miR-204 and the biological consequences of miR-204 perturbation. Then we validate the data obtained in a cohort of tumoral and normal gastric samples, tumoral and normal cholangiocarcinoma samples. to statistically strengthen the genes signature obtained we analyzed data available on gastric, colangiocarcinoma, esophageal and colon database
