Gene expression analyses of mir-31 overexpression in ovarian serous cancer cell line

A variety of human cancers demonstrate alterations in microRNA expression. We hypothesized that regulatory defects in microRNAs play a central early role in organizing the molecular changes involved in ovarian cancer (OvCa). Using both gene arrays and deep sequencing, we comprehensively profiled mRNA and microRNA expression, respectively, in human serous epithelial OvCa cell lines, serous tumors, and short-term primary cultures of normal ovarian surface epithelium (NOSE). We expected that over-expression of a specific microRNA would lead to lower expression of its mRNA targets, and under-expression of a specific microRNA would lead to higher expression of its target genes. Using our expression data in conjunction with established in silico algorithms, we found putative microRNA:mRNA functional pairs. Furthermore, gene expression profiles were taken of serous cultures having functional knockdown or over-expression of specific microRNAs of interest. Over-expression of mir-31 (found under-expressed in serous OvCa) resulted in down-regulation in vitro of a significant number of the in silico predicted mir-31 target genes. Keywords: two group comparison We used miRNA mimics to over-express mir-31, originally found under-expressed in OvCa. After 48 hours of mimic treatment, we profiled for gene expression both cells with mir-31 knockup and cells with mimic control (having minimal sequence identity with all human miRNAs).