Additive effects of cepharanthin in CDDP/hyperthermia combination therapy against transplantable human esophageal cancer in nude mice.

Abstract

Additive effects of cepharanthin in CDDP/hyperthermia combination therapy were evaluated. Nude mice bearing a transplantable human esophageal cancer (ES0-2), classified histologically as a moderately differentiated squamous cell carcinoma, were treated with cepharanthin (20 mg/kg IP) in addition to cis-diamminedichloroplatinum(II) (CDDP; 4 mg/kg IP) and/or hyperthermia at 42 degrees C for 30 min, to determine the additive effects of cepharanthin. Furthermore, effects of cepharanthin on intratumoral concentration of CDDP were evaluated. Cepharanthin itself did not have an anti-tumor effect. This agent did not enhance the anti-tumor effect of CDDP alone, but enhanced the anti-tumor effects of both 42 degrees C hyperthermia alone, and combination therapy with CDDP and 42 degrees C hyperthermia. The concentration of CDDP in the tumors treated by 42 degrees C hyperthermia was slightly higher than in nonheated tumors. Cepharanthin did not affect the intratumoral concentration of CDDP, irrespective of whether hyperthermia was applied. Cepharanthin enhanced the effect of CDDP/hyperthermia combination therapy through thermoenhancing effect.