Expression data from A2780 (cisplatin-sensitive) and Round5 A2780 (cisplatin-resistant) cell lines.

Cisplatin and carboplatin are the primary first-line therapies for the treatment of ovarian cancer. However, resistance to these platinum-based drugs occurs in the large majority of initially responsive tumors, subsequently resulting in a poor long-term prognosis. To model the onset of drug resistance, we measured gene expression alterations associated with cisplatin resistance. We treated clonally derived, drug-sensitive A2780 epithelial ovarian cancer cells with increasing concentrations of cisplatin. After 5 cycles of drug selection, the isogenic drug-sensitive (parental A2780) and -resistant (Round5 A2780) cell lines were subjected to mRNA expression microarray analyses.