MicroRNAs (miRNAs) are crucial molecules that regulate gene expression and hence pathways that are key to prostate cancer progression. These non-coding RNAs are highly deregulated in prostate cancer thus facilitating progression of the disease. Among the many genes that have gained importance in this disease, Migration and invasion enhancer 1 (MIEN1), a novel gene located next to HER2/neu in the 17q12 amplicon of the human chromosome, has been shown to enhance prostate cancer cell migration and invasion, two key processes in cancer progression. MIEN1 is differentially expressed between normal and cancer cells and tissues. Understanding the regulation of MIEN1 by microRNA may enable development of better targeting strategies and as a result, was the focus of a recent study by researchers from the University of North Texas Health Science Center. In their study, the miRNAs that could target MIEN1 were predicted by in silico algorithms and LC Sciences’ custom miRNA microarray analysis. The validation for miRNA expression was performed by qPCR and northern blotting in cells and by in situ hybridization in tissues. MIEN1 and levels of other molecules upon miRNA regulation was determined by Western blotting, qPCR, and immunofluorescence. The functional effects of miRNA on cells were determined by wound healing cell migration, Boyden chamber cell invasion, clonal and colony formation assays. For knockdown or overexpression of the miRNA or overexpression of MIEN1 3′UTR, cells were transfected with the oligomiRs and plasmids, respectively. A novel miRNA, hsa-miR-940 (miR-940), identified and validated to be highly expressed in immortalized normal cells compared to cancer cells, was a regulator of MIEN1. Analysis of human prostate tumors and their matched normal tissues confirmed that miR-940 is highly expressed in the normal tissues compared to its low to negligible expression in the tumors. While MIEN1 is a direct target of miR-940, miR-940 alters MIEN1 RNA, in a quantity as well as cell dependent context, along with altering its downstream effectors. The miR-940 inhibited migratory and invasive potential of cells, attenuated their anchorage-independent growth ability, and increased E-cadherin expression, implicating its role in mesenchymal-to-epithelial transition (MET). These results, for the first time, implicate miR-940, a regulator of MIEN1, as a promising novel diagnostic and prognostic tool for prostate cancer.
miR-940 alters the anchorage-dependent and -independent growth of DU-145 cells
(A) Morphology (left) and number (right) of colonies formed by Pre-miR-NT or Pre-miR-940 transfected DU-145 cells after 12 days on tissue culture treated adherent plates. (B) Soft agar colony formation assay shows the colonies in the agar (left) and their quantification (right) after 12 days. (C-D) Immunofluorescence (C) and western blotting (D) show the expression and localization of various proteins upon overexpression of Pre-miR-940 compared to Pre-miR-NT.
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miRNA Microarray Service – LC Sciences provides a microRNA (miRNA) expression profiling service using microarrays based on our in-house developed µParaflo® technology platform. We have standard arrays for all mature miRNAs of all species available in the latest version of the miRBase database (Release 21, July 2014). Our service is comprehensive and includes sample labeling, array hybridization, image data processing and in-depth data analysis. Two-three weeks after receiving your total RNA samples, we’ll send you both the raw and fully analyzed data. [Learn more…]
Reference
Smrithi Rajendiran, Anil V Parwani, Richard J Hare, Subhamoy Dasgupta, Rhonda K Roby, Jamboor K Vishwanatha (2014) MicroRNA-940 suppresses prostate cancer migration and invasion by regulating MIEN1 Molecular Cancer 13:250 doi:10.1186/1476-4598-13-250 [article]