목적: The aim of this study was to evaluate the in vitro effect of Hsp90 inhibitor, on paclitaxel-resistant ovarian cancer cells, and explore the mechanism of apoptosis. 방법: In the present study, the author used Hsp90 inhibitor in combination with paclitaxel (PTX) to determine its effect on cell proliferation and apoptosis in PTX-resistant human ovarian carcinoma cell line. The drug-resistant tumor cell lines were established in vitro by stepwise sequential exposure to increased concentration of PTX. 결과: The cell viability and cell cycle distribution were measured by MTT and flow cytometric analysis. The induction of apoptosis was measured by caspase-3 activity, DNA fragmentation and western blot analysis. The cell viability was significantly decreased after treatment with combination treatment compared with either drug used alone. DNA fragmentation assay revealed apoptosis induction. The flow cytometry result showed an increase in G2/M phase. Downregulation of Bcl-2, XIAP, Survivin, Akt and NF-κB, and upregulation of Bax were observed. 결론: The role of Hsp90 inhibitor may contribute to the induction of apoptosis in PTX-resistant ovarian cancer cells. These results suggest Hsp90 inhibitor in combination with PTX may be a benefical chemotherapeutic strategy, especially in patients with tumors refractory to PTX alone.