Sensitisation of human ovarian carcinoma cells to cis-diamminedichloroplatinum (II) by amphotericin B in vitro and in vivo.

Human ovarian carcinoma cells (HRA) were sensitised to cis-diamminedichloroplatinum (II) (CDDP) 2.7-, 5.5- and 12.1-fold by treatment with amphotericin B (AMB) at concentrations of 2.1, 5.4 and 10.8 microM, respectively. Moreover, intracellular accumulation of platinum after a 2-h exposure to CDDP was increased significantly with AMB treatment. We prepared HRA cell-inoculated nude mice as an experimental therapeutic model for human advanced ovarian carcinoma. Ascites was evident after 7 to 9 days of intra-peritoneal (i.p.) inoculation of HRA cells, and mice died due to intra-abdominal carcinomatosis after 11 to 14 days [mean survival time (MST): 12.4 +/- 1.1 days]. Treatment with AMB (2.0 mg/kg) alone 4 days after inoculation increased MST by only 1.4 days. Simultaneous treatment with CDDP (1.0 to 2.0 mg/kg) and AMB (0.5 to 2.0 mg/kg) produced a significant increase in MST compared to treatment with CDDP alone. Maximal MST (30.1 days) was observed by treatment with 2.0 mg/kg CDDP plus 2.0 mg/kg AMB, whereas MST with 2.0 mg/kg CDDP alone was 16.4 days. A further drug accumulation study demonstrated that platinum accumulation in tumour tissues in nude mice treated with CDDP and AMB increased significantly compared to treatment with CDDP alone. These results indicate that intraperitoneal combination chemotherapy with CDDP and AMB is effective in an experimental animal model of advanced ovarian carcinoma.