Resistant, recurrent ovarian cancer patients who had first chemotherapy with Cisplatin have showed low reactivity and high recurrence in the secondary chemotherapy. Therefore, multi-drug resistance (MDR) to chemotherapy is a major obstacle in attempts to improve the clinical outcome of ovarian cancer patients. The aim of our study is to analyze the sensitivity of some chemotherapy drugs when we co-use Cyclosporine A (CsA), which suppresses MDR, in the secondary drug resistant cell line.

After establishing the secondary drug resistant cell line, drug sensitivity was measured by MTT assay. MDR gene and protein were analyzed by RT-PCR and western blotting assay.

MDR gene (MDR1) and protein (P-gp) were overexpressed in the secondary drug resistant cell line. When we measured the sensitivity of some chemotherapy drug after using the amounts of CsA that can suppress MDR1/P-gp, the sensitivity of Paclitaxel was highest.

CsA has a role that makes the sensitivity of chemotherapy drug higher in the secondary drug resistant cell line by suppression of multi-drug resistance. Therefore, we could expect that the proper use of MDR suppresser like CsA with secondary chemotherapy drug would help to cure resistant, recurrent ovarian cancer patients.