Clusterin interacts with Paclitaxel and confer Paclitaxel resistance in ovarian cancer.
Optimal debulking followed by chemotherapy is the standard treatment of managing late-stage ovarian cancer, but chemoresistance is still a major problem. In this study, we compared expression profiles of primary tumor tissue from five long-term (>8 years) and five short-term (<2 years) ovarian cancer survivors and identified clusterin as one of the genes that were significantly up-regulated in short-term survivors. We then evaluated the prognostic significance of clusterin and its possible correlation with chemoresistance in ovarian cancer by immunohistostaining of clusterin in 62 tumor samples from patients with stage III, high-grade serous ovarian cancer. After adjusting for debulking status and age, Cox regression analyses showed that high levels of clusterin expression correlate with poor survival (hazard ratio, 1.07; 95% confidence interval, 1.002-1.443; P = .04). We also investigated clusterin in paclitaxel resistance by modulating the endogenous clusterin expression in ovarian cancer cells and treating the cells with purified clusterin. Results indicate that high-clusterin-expressing ovarian cancer cells are more resistant to paclitaxel. Moreover, exposing ovarian cancer cells to exogenous clusterin increases cells' resistance to paclitaxel. Finally, using size exclusion chromatography and fluorescently labeled paclitaxel, we demonstrated that clusterin binds to paclitaxel. In summary, our findings suggest that high levels of clusterin expression increase paclitaxel resistance in ovarian cancer cells by physically binding to paclitaxel, which may prevent paclitaxel from interacting with microtubules to induce apoptosis. Thus, clusterin is a potential therapeutic target for enhancing chemoresponsiveness in patients with a high-level clusterin expression.
Park
Dong Choon
DC
Department of Obstetrics and Gynecology, Saint Vincent's Hospital, The Catholic University of Korea, Suwon, Republic of Korea.
Yeo
Seung Geun
SG
Wilson
Mark R
MR
Yerbury
Justin J
JJ
Kwong
Joseph
J
Welch
William R
WR
Choi
Yang Kyu
YK
Birrer
Michael J
MJ
Mok
Samuel C
SC
Wong
Kwong-Kwok
KK
D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D051152:Clusterin / Q000096:biosynthesis*; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D009367:Neoplasm Staging; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000473:pathology; D017239:Paclitaxel / Q000494:pharmacology*; D015854:Up-Regulation
D000972:Antineoplastic Agents, Phytogenic; D051152:Clusterin; D017239:Paclitaxel