Molecular profiling of ovarian carcinoma platinum-sensitive and -resistant cell lines (microRNAs)

Resistance to platinum compounds represents a major obstacle to the cure of ovarian carcinoma. The molecular profiling of drug-sensitive and drug-resistant cells may be helpful to clarify if altered expression of miRNAs can contribute to the drug-resistant phenotype. The expression pattern of miRNAs of three ovarian carcinoma cell lines was examined. The analysis revealed the modulation of several miRNAs in the two platinum-resistant cell lines as compared to parental platinum-sensitive cells. The integration of the information obtained through miRNA expression analysis may be useful to clarify the specific molecular alterations of factors and pathway favouring survival of tumor cells. To examine the expression patterns of miRNAs in platinum-sensitive cells versus platinum-resistant cells, we used three ovarian carcinoma cell lines: the parental cisplatin-sensitive IGROV-1 cell line, the platinum-resistant variants IGROV-1/Pt1, generated by exposure of parental cells to cisplatin and IGROV-1/OHP, obtained by exposure of parental cells to oxaliplatin. Three independent samples for each cell line were prepared. Exponentially growing cells were harvested using trypsin and counted. Cells were centrifuged and pellets (10 million cells/sample) were immediately frozen in liquid nitrogen. miRNAs were isolated and microarrays were run. Overall, nine samples were analysed consisting of three biological replicates for each cell line.