Ex vivo Efficacy of Anti-Cancer Drug PNC-27 in the Treatment of Patient-Derived Epithelial Ovarian Cancer

Despite an 80% response rate to chemotherapy, epithelial ovarian cancer has the highest case fatality rate of all gynecologic malignancies. Several studies have shown the efficiency of anticancer peptides PNC-27 and PNC-28 in killing a variety of cancer cells selectively in vitro and in vivo. The purpose of this study was to evaluate the efficacy of PNC-27 against human primary epithelial ovarian cancer. We established primary cultures of freshly isolated epithelial ovarian cancer cells from patients with newly diagnosed ovarian cystadenocarcinomas. Two cell lines were obtained, one from mucinous cystadenocarcinoma, and the other from high-grade papillary serous carcinoma. The cancerous properties of these cells were characterized in vitro morphologically, by their growth requirements and serum independence. Treatment effects with PNC-27 were followed qualitatively by light microscopy, and quantitatively by measuring inhibition of cell growth using the MTT cell proliferation assay and direct cytotoxicity by measuring lactate dehydrogenase (LDH). PNC-27 inhibits in a dose-dependent manner the growth of and is cytotoxic to human primary cancer cells that had been freshly isolated from two ovarian epithelial cancers. The results further show that the control peptide PNC-29 has no effect on the primary cancer cells. Our results also show that PNC-27 is cytotoxic to cells from long-established and chemotherapy-resistant human ovarian cancer cell lines. These findings show, for the first time, the efficacy of PNC-27 on freshly isolated, primary human cancer cells. Our results indicate the potential of PNC-27 peptide as an efficient alternative treatment of previously untreated ovarian cancer as well as for ovarian cancers that have become resistant to present chemotherapies.