Harper Amy K, Fletcher Nicole M, Fan Rong, Morris Robert T, Saed Ghassan M
Division of Gynecologic Oncology, Karmanos Cancer Institute, Detroit, MI, USA.
The C.S. Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, MI, USA.
Reprod Sci. 2020 Apr;27(4):1030-1036. doi: 10.1007/s43032-019-00089-2. Epub 2020 Mar 2.
HSP60 is a mitochondrial chaperone protein that is associated with decreased overall survival of ovarian cancer patients. We determined whether targeting HSP60 with its monoclonal antibody would induce cytotoxicity in sensitive and chemoresistant ovarian cancer cells and whether it is synergistic when combined with chemotherapeutic drugs. Epithelial ovarian cancer (EOC) cells and their docetaxel- or cisplatin-resistant counterparts were utilized. HSP60 mRNA levels were determined by real-time RT-PCR. Cytotoxicity of HSP60 antibody (0.5 or 1.5 μg/ml) alone and in combination with chemotherapy were assessed by MTT Cell Proliferation Assay. Unpaired t tests were used to compare groups for real-time RT-PCR. One-way ANOVA followed by Tukey's post hoc tests with Bonferroni correction was performed for cytotoxicity comparisons. Significant synergistic effects of the antibody combined with chemotherapy were determined by the CompuSyn Software. Basal HSP60 mRNA levels were increased in chemoresistant EOC cells as compared with their sensitive counterparts (p < 0.05). There was no significant difference in cytotoxicity between EOC cell types; however, treatment with the HSP60 antibody for 24 h showed a dose response (0.5 and 1.5 μg/ml) cytotoxic effect to both sensitive and chemoresistant EOC cells as compared with the isotype control (p < 0.05). Importantly, treatment with both doses of HSP60 antibody was not cytotoxic to normal macrophages. Combination of the HSP60 antibody with docetaxel or cisplatin was significantly synergistic in both sensitive and chemoresistant EOC cells. Here, we identify a novel target that may serve not only for ovarian cancer treatment but also for sensitization of patients to chemotherapy. The cytotoxic effect of HSP60 monoclonal antibody and its synergism with chemotherapeutic agents highlight HSP60 as a promising target for therapy and chemosensitization in ovarian cancer treatment.
热休克蛋白60（HSP60）是一种线粒体伴侣蛋白，与卵巢癌患者总体生存率降低相关。我们研究了用其单克隆抗体靶向HSP60是否会在敏感和化疗耐药的卵巢癌细胞中诱导细胞毒性，以及与化疗药物联合使用时是否具有协同作用。使用了上皮性卵巢癌（EOC）细胞及其对多西他赛或顺铂耐药的对应细胞。通过实时逆转录聚合酶链反应（RT-PCR）测定HSP60 mRNA水平。通过MTT细胞增殖试验评估单独使用HSP60抗体（0.5或1.5μg/ml）以及与化疗联合使用时的细胞毒性。采用非配对t检验比较实时RT-PCR的各组。对细胞毒性比较进行单因素方差分析，随后进行Tukey事后检验并采用Bonferroni校正。通过CompuSyn软件确定抗体与化疗联合使用的显著协同作用。与敏感的EOC细胞相比，化疗耐药的EOC细胞中基础HSP60 mRNA水平升高（p < 0.05）。EOC细胞类型之间的细胞毒性没有显著差异；然而，与同型对照相比，用HSP60抗体处理24小时对敏感和化疗耐药的EOC细胞均显示出剂量反应（0.5和1.5μg/ml）细胞毒性作用（p < 0.05）。重要的是，两种剂量的HSP60抗体处理对正常巨噬细胞均无细胞毒性。HSP60抗体与多西他赛或顺铂联合使用在敏感和化疗耐药的EOC细胞中均具有显著协同作用。在此，我们确定了一个新靶点，其不仅可用于卵巢癌治疗，还可用于使患者对化疗敏感。HSP60单克隆抗体的细胞毒性作用及其与化疗药物的协同作用突出了HSP60作为卵巢癌治疗中一个有前景的治疗和化疗增敏靶点。
