Growth-inhibitory signals by activin A do not affect anticancer drug-sensitivity and acquired multi-drug-resistance in human ovarian endometrioid adenocarcinoma OVK-18 cells.
Using the human ovarian adenocarcinoma cell line, OVK-18, which is sensitive to activin A-mediated inhibition of growth and various anticancer drugs, we determined whether activin A altered the sensitivity of these cells to seven anticancer drugs. The relationship between the sensitivity to activin and the resistance to anticancer drugs was also investigated in OVK-18 parent cells and OVK-18-derived CDDP-resistant cells. Activin A inhibited proliferation of OVK-18 parent cells in a dose-dependent manner, although it did not affect the sensitivity of OVK-18 parent cells to the seven anticancer drugs, CDDP, CBDCA, adriamycin, paclitaxel, SN38, terarubicin and etoposide (VP16). Both the sensitivity to activin A-mediated inhibition of growth and the sensitivity to anticancer drug-induced apoptosis were reduced in CDDP-resistant cells, while their sensitivity to the seven anticancer drugs was not affected by activin A. Flow cytometric analysis revealed a significant reduction in type IIA activin receptor expression on the surface of CDDP-resistant cells. These results indicate that the activin A-induced intracellular signals inhibiting cell growth are independent of the inhibition caused by the seven anticancer drugs, and suggest that the reduced sensitivity of CDDP-resistant cells to activin A is derived in part from reduced activin receptor expression and not acquired drug-resistance.
Tanaka
Tetsuji
T
Department of Obstetrics and Gynecology, Wakayama Medical University, Wakayama 641-0012, Japan. tetanaka@wakayama-med.ac.jp
Toujima
Saori
S
Umesaki
Naohiko
N
D028341:Activins / Q000502:physiology*; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002455:Cell Division; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D028322:Inhibin-beta Subunits / Q000502:physiology*; D010051:Ovarian Neoplasms / Q000188:drug therapy* / Q000473:pathology; D012680:Sensitivity and Specificity
D000970:Antineoplastic Agents; C422405:activin A; D028341:Activins; D028322:Inhibin-beta Subunits