Differential gene expression between borderline and adenocarcinoma in ovarian cancer

Ovarian tumors of the borderline subtype (BOL) are epithelial cancers tumors with very specific features. They rarely progress towards malignancy but their evolutionary profile, although remaining local, is distinct from that of benign cancers. At the cellular level, BOL are undistinguishable from malignant tumors (cytonuclear abnormalities, abnormal mitoses, anarchical proliferation), however they never invade the stroma, which makes them clearly distinct from carcinoma. BOL tumors are of good prognosis. Even when they relapse, these tumors remain local and are, most of the time, not invasive. Thus, comparing BOL with ovarian adenocarcinomas (ADK) is of major interest to decipher potential gene alterations underlying the process of invasion, a key step of oncogenesis. In this study, 20 BOL and 19 ADK were recruited at the Gustave Roussy, frozen and analyzed by pathologists. RNA extraction followed by gene expression analysis, in association with clinical and histological data of these two groups of tumors, may provide a gene signature characterizing ovarian cancer invasion. Gene expression was performed in dual color on Agilent Whole Human Genome Oligo Microarray A-AGIL11(design 012391). Differential expression has been analysed between the 2 sets of ovary samples : 19 ADK and 20 BOL labelled in one color (Cy5) versus a pool of all samples (Cy3).