Profiling of proteins associated with cisplatin resistance in ovarian cancer cells

Resistance to cisplatin is a major impediment to the successful treatment of ovarian cancer, but the precise nature of the resistance is still unclear. In the current study, we aimed to investigate and compare the protein expression profiles in cisplatin-sensitive and cisplatin-resistant ovarian cancer cell lines. We employed the recent development of surface-enhanced laser desorption/ionization ProteinChip technology to measure protein expression in three human ovarian cancer cell lines (KF-1, MN-1, and A2780) and their sublines (KF-r, MN-r, and A2780cp) resistant to cisplatin. The ProteinChip Arrays were analyzed using the ProteinChip Reader. We did not find any regularity in protein expressions in secretions of cisplatin-sensitive and cisplatin-resistant cells. But on the IMAC3 array, we captured 12 identical expressions which represent a subset of proteins whose expression levels are different between parent ovarian cancer cells and their cisplatin-resistant cells. In particular, at the molecular weight of 7829 d, three kinds of parent cell lines exhibited an elevated expression and their cisplatin-resistant sublines revealed a lowered expression. At the molecular weight of 6881 d, for KF and MN cell lines, opposite protein expressions were seen in the parent cell line and its cisplatin-resistant subline. We think the interesting protein expressions perhaps suggest some mechanisms involved in cisplatin resistance.