Micro RNA-142-5p Profile as a Predictor of Tumor Markers Regulation in Different Histological Grades of Human Breast Carcinoma

Abstract

Micro RNA (miRNA) is one of the kinds in non coding RNA class that regulates gene expression by translational repression, mRNA cleavage, mRNA disruption initiated by miRNA-guided rapid de-adenylation. Up- and/or down-regulated expression study of the miRNA is a good approach to study their function in cancer pathogenesis. In our previous study we understood the down regulation of polycomb gene BMI1 and its correlation with histochemical markers like ER, PR and Her2 in different histological grades of breast tumors. To derive on the identification of regulatory factor accountable for this gene regulation pattern, we tried to identify miRNA that could sway on the gene regulation with the consecutive tumor grades. To adequate this perspective we identified miR-142-5p as a regulating marker for the proliferation of human ductal invasive breast carcinoma using microarray hybridization and attempted to demonstrate the expression profile of miR-142-5p in various histological grades of human breast carcinoma using Real time-PCR amplification. The up regulation of miR-142-5p in histological Grades I, II and III predicted variation with the hormone receptor status. The miR-142-5p up regulation was vice versa with the down regulation of BMI1 gene in the tumors from Grade I to Grade III. Hence with the severity in tumor the up regulated miR-142-5p was estimated to show substantial regulatory effect on expression of the histological markers and polycomb gene BMI1. These signatures shall hold on the diagnosis and therapy for human breast carcinoma.