Apoptosis Induced by Doxorubicin and Cinchonine in P388 Multidrug-Resistant Cells

S Furusawa, S Nakano, J Wu, S Sakaguchi, M Takayanagi, K I Sasaki, S Satoh

J Pharm Pharmacol. 2001 Jul;53(7):1029-39.

PMID: 11480538

Abstract:

Acquired drug resistance is a major factor in the failure of doxorubicin-based cancer chemotherapy. We determined the ability of cinchonine to reverse doxorubicin drug resistance in a doxorubicin-resistant leukaemia cell line (mouse P388/DOX). A non-cytotoxic concentration of cinchonine (10 microM) increased the sensitivity to doxorubicin of multidrug-resistant P388/DOX cells and significantly enhanced the doxorubicin-induced apoptosis and DNA fragmentation in resistant cells, but had no effect in parent cells. Time-course studies demonstrated that DNA fragmentation was present 24 h after incubation with doxorubicin and cinchonine, indicating that DNA degradation was a preceding event. In cultured cells, cinchonine increased the intracellular accumulation of doxorubicin in the resistant cells in a dose-dependent manner. Using flow cytometry to measure the inhibition of the P-glycoprotein (P-gp) dependent efflux of rhodamine 123, cinchonine was found to be considerably more effective than quinine. The results with cinchonine suggest that there may be quinine derivatives with a similar capacity to inhibit drug transport by P-gp. Additionally, the G2/M phase cell population in resistant cells is increased by doxorubicin/cinchonine treatment. Exposure of resistant cells to 1 microM doxorubicin and 10 microM cinchonine resulted in the expression of Fas (APO-1/CD95) in cells after 6 h. These studies demonstrate that the cell killing effects of doxorubicin and cinchonine in resistant cells

Chemicals Related in the Paper:

Catalog Number	Product Name	Structure	CAS Number	Price
AP118105	(+)-Cinchonine		118-10-5	Price