Department of Obstetrics and Gynecology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
J Exp Clin Cancer Res. 2011 Dec 20;30(1):113. doi: 10.1186/1756-9966-30-113.
Clusterin is a cytoprotective chaperone protein involved in numerous physiological processes, carcinogenesis, tumor growth and tissue remodelling. The purpose of this study was to investigate whether clusterin (CLU), an antiapoptotic molecule, could be a potential predictor molecule for ovarian cancer and whether or not targeting this molecule can improve survival of ovarian cancer patients.
Clusterin expression was compared between ten primary and their recurrent tumors from same patients immunohistochemically. We analyzed prognostic significance of CLU expression in another 47 ovarian cancer tissue samples by immunohistochemistry. We used small interference RNA to knock down CLU in the chemo-resistant ovarian cancer cell lines. KF-TX and SKOV-3-TX, paclitaxel-resistant ovarian cancer cells, were established from parental KF and SKOV-3 chemo-sensitive cell lines, respectively. Either siRNA or second generation antisense oligodeoxynucleotide against CLU (OGX-011), which is currently evaluated in clinical phase II trials in other cancer s, was used to modulate sensitivity to paclitaxel (TX) in ovarian cancer cells in vitro. Cellular viability assay, FACS analysis and annexin V staining were used to evaluate the comparative effect of CLU knocking down in ovarian cancer cells.
Immunohistochemical analysis of CLU expression in primary ovarian cancer tissue specimens and their recurrent counterparts from same patients demonstrated higher expression of CLU in the recurrent resistant tumors compared with their primary tumors. High expression of CLU by immunohistochemistry among 47 surgical tissue specimens of early-stage (stage I/II) ovarian cancer, who underwent complete cytoreduction as a primary surgery, significantly related to poor survival, while none of other clinicopathological factors analyzed were related to survival in this patient cohort. Secretory CLU (s-CLU; 60 KDa) expression was upregulated in TX-resistant ovarian cancer cells compared to parental cells. Transfection of siRNA or OGX-011 clearly reduced CLU expression. Cell viability assay, FACS analysis and annexin V staining demonstrated that targeting CLU expression by siRNA or OGX-011 sensitized ovarian cancer cells to TX.
We conclude that CLU could be a potential molecular target to predict survival while targeting this s-CLU may improve survival of patients with ovarian cancer.
簇集蛋白是一种参与多种生理过程、致癌作用、肿瘤生长和组织重塑的细胞保护性伴侣蛋白。本研究的目的是研究簇集蛋白（CLU），一种抗凋亡分子，是否可以作为卵巢癌的潜在预测分子，以及靶向该分子是否可以改善卵巢癌患者的生存。
采用免疫组织化学法比较 10 例原发性和同一患者复发性肿瘤之间的簇集蛋白表达。我们通过免疫组织化学法分析了 47 例卵巢癌组织样本中 CLU 表达的预后意义。我们使用小干扰 RNA 敲低化疗耐药卵巢癌细胞系 KF-TX 和 SKOV-3-TX 中的 CLU。KF 和 SKOV-3 化疗敏感细胞系分别建立紫杉醇耐药卵巢癌细胞系 KF-TX 和 SKOV-3-TX。siRNA 或第二代针对 CLU 的反义寡脱氧核苷酸（OGX-011），目前正在其他癌症的临床二期试验中进行评估，用于体外调节卵巢癌细胞对紫杉醇（TX）的敏感性。细胞活力测定、FACS 分析和膜联蛋白 V 染色用于评估卵巢癌细胞中 CLU 敲低的比较效果。
对原发性卵巢癌组织标本及其复发性肿瘤组织标本中 CLU 表达的免疫组织化学分析表明，与原发性肿瘤相比，复发性耐药肿瘤中 CLU 的表达更高。在接受初次手术完全减瘤的早期（I/II 期）卵巢癌 47 例手术组织标本中，免疫组化高表达 CLU 与不良生存显著相关，而本患者队列中其他临床病理因素均与生存无关。与亲本细胞相比，紫杉醇耐药卵巢癌细胞中分泌型 CLU（s-CLU；60 kDa）表达上调。siRNA 或 OGX-011 转染可明显降低 CLU 表达。细胞活力测定、FACS 分析和膜联蛋白 V 染色表明，siRNA 或 OGX-011 靶向 CLU 表达可使卵巢癌细胞对 TX 敏感。
我们的结论是，CLU 可能是预测生存的潜在分子靶点，而靶向该 s-CLU 可能改善卵巢癌患者的生存。
