Functional study of microRNAs miR-450a and miR-450b-5p in tumorigenesis

Abstract

MicroRNAs (miRNAs) are small noncoding RNA molecules that act on the cell molecular circuits in important biological processes such as development, cell proliferation, differentiation, metabolism and apoptosis. Changing levels of miRNAs are a cause or effect of tumorigenesis and currently many of them operate as oncogenes or tumor suppressor genes. Until the moment, 2.578 miRNAs in human have been described and approximately 10% of them are located on chromosome X. Several of these are associated with cancer progression. In studies conducted as part of my dissertation, it was found that two miRNAs, miR - 450a and miR-450b-5p, still little explored and located in the Xq26 region, were overexpressed in a panel of normal tissues compared to a panel of tumor cell lines. A third miRNA, miR-424, which is located in the same region and is functionally characterized as a tumor suppressor, was co-expressed with miRNAs miR-450a and miR-450b-5p in normal tissues. Based on the preliminary results of our study and the evidence of other authors, we suggest that the higher expression of these miRNAs in certain tumor cells could attenuate the phenotypes associated with tumorigenesis. Therefore, the aim of this project is to conduct in vitro studies to characterize the role of putative suppressor miRNAs miR-450a and miR-450b-5p in tumorigenesis.