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

2017-04-10 | GSE81948 | GEO

Homo sapiens foetal mesenchymal stem cell miRNA transcriptome

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

2014-08-06 | GSE58734 | GEO

MiR-204-5p may Regulate Oxidative Stress in Myopia and Myopia-Related Retinopathy

Project description:Introduction: The mechanisms underlying myopia and myopia-related retinopathy remain not fully understood. We proposed to examine the function and underlying mechanisms of miR-204-5p in myopia development. Methods: The miR-204-5p expression level was assessed in the vitreous humor (VH) of a cohort consisting of 11 patients with high myopia (HM) and 16 control patients undergoing retinal surgery. The functional implications of miR-204-5p in ARPE-19 cells were assessed, encompassing cell aggressiveness. Thioredoxin-interacting protein (TXNIP) was found as a possible target of miR-204-5p through mRNA sequencing, and its interaction with miR-204-5p was confirmed employing luciferase assay and western blotting. Furthermore, the miR-204-5p function in regulating oxidative stress was examined by measuring reactive oxygen species (ROS) accumulation. Results: miR-204-5p was found to be significantly reduced in the VH of HM patients. Overexpression of miR-204-5p suppressed cell proliferation, migration, invasion, and apoptosis in ARPE-19 cells. The bioinformatics analysis demonstrated that miR-204-5p can modulate the genes associated with pathways relevant to myopia, including glycosaminoglycan (GAG) degradation, lysosome, and TGF−beta signaling pathway. The direct targeting of miR-204-5p on TXNIP has been confirmed through validation, and its downregulation mediated the miR-204-5p impacts on ARPE-19 cells. Moreover, miR-204-5p overexpression significantly reduced ROS accumulation by targeting TXNIP. Conclusion: Our findings revealed the possible contribution of the miR-204-5p/TXNIP axis in myopia development by regulating oxidative stress, which may provide new targets and novel therapeutic strategies to combat this prevalent and debilitating condition.

2024-01-26 | GSE253960 | GEO

Homo sapiens

Project description:Identification of miR-145 or miR-133a target genes in squamous cell carcinoma

| PRJNA124113 | ENA