Treatment of Chemotherapy-Resistant Human Ovarian Cancer by Administration of CPE

描述(申请人提供)：卵巢癌仍是妇科肿瘤中死亡率最高的癌症。尽管许多卵巢癌患者对手术和化疗的标准组合完全有效，但近90%的人后来发展为复发的化疗耐药癌症，不可避免地屈服于他们的疾病。因此，开发针对复发/耐化疗卵巢癌的创新、有效的治疗方法仍然是改善公共卫生的高度优先事项。利用高通量技术分析卵巢癌的遗传指纹，我们最近发现编码蛋白claudin-3和claudin-4的基因表达极高。由于Claudin-3和Claudin-4是产气荚膜梭菌肠毒素(CPE)的上皮受体，足以介导CPE结合，从而触发随后的毒素介导的细胞溶解，因此我们假设，基于卵巢癌细胞高水平的Claudin-3和-4，使用CPE靶向其可能是一种新的、高效的治疗卵巢癌化疗耐药的方法。与这一观点一致，我们将CPE引入从几种过表达claudin-3和-4的原发、转移性和化疗耐药的卵巢癌培养的细胞中，我们发现这些肿瘤细胞不同于健康的人类组织，对CPE介导的细胞溶解高度敏感。更重要的是，我们发现，在携带高度相关的化疗耐药人卵巢癌临床模型的SCID小鼠异种移植瘤中，经腹膜腔内CPE治疗可100%抑制已确定疾病1周的小鼠的肿瘤生长。因此，使用CPE靶向高水平的claudin-3和-4可能是一种创新的、潜在的高效治疗方法，可以杀死转移性和/或化疗耐药的卵巢癌细胞。因此，这项建议有三个相关的具体目标：1)研究claudin-3和-4在卵巢癌中的表达及其调控；2)表征卵巢癌细胞对CPE介导的细胞溶解的敏感性和耐药性；以及3)在体内检测CPE治疗的药代动力学、疗效和毒性。在这个项目完成后，我们将能够迅速将这项研究转化为治疗化疗耐药疾病患者的新临床疗法。卵巢癌仍然是妇科恶性肿瘤中最致命的，高达90%的晚期卵巢癌患者死于复发的化疗耐药肿瘤；因此，开发这种疾病的新疗法是改善公共卫生的首要任务。拟议的研究结果将为一种创新的、潜在的高效治疗卵巢癌化疗耐药患者的快速临床转化奠定基础。

DESCRIPTION (provided by applicant): Ovarian carcinoma remains the cancer with the highest mortality rate among gynecological tumors. Although many ovarian cancer patients fully respond to the standard combination of surgery and chemotherapy, nearly 90% later develop recurrent chemotherapy-resistant cancer and inevitably succumb to their disease. Thus, development of innovative, effective therapies against recurrent/chemotherapy-resistant ovarian cancer remains a high priority for improving public health. Using high-throughput technologies to analyze genetic fingerprints of ovarian cancer, we have recently discovered extremely high expression of the genes encoding the proteins claudin-3 and claudin-4. Because claudin-3 and -4 are the epithelial receptors for Clostridium perfringens enterotoxin (CPE) and are sufficient to mediate CPE binding, which triggers subsequent toxin-mediated cytolysis, we hypothesize that using CPE to target ovarian cancer cells based on their high levels of claudin-3 and -4 is potentially a novel, highly effective therapeutic approach for chemotherapy-resistant ovarian cancer. Consistent with this view, we introduced CPE to cells cultured from several primary, metastatic, and chemotherapy-resistant ovarian cancers that overexpress claudin-3 and -4, and we found that these tumor cells, unlike healthy human tissues, are highly sensitive to CPE-mediated cytolysis. More importantly, we found that intraperitoneal CPE therapy in SCID mouse xenografts harboring a highly relevant clinical model of chemotherapy-resistant human ovarian cancer inhibited tumor growth in 100% of mice harboring 1-week established disease. Thus, using CPE to target the high levels of claudin-3 and -4 may represent an innovative, potentially highly effective therapeutic approach to kill metastatic and/or chemotherapy-resistant ovarian cancer cells. Accordingly, this proposal has three related specific aims: 1) Characterize profiles and regulation of expression of claudin-3 and -4 in ovarian cancer; 2) Characterize sensitivity and resistance of ovarian cancer cells to CPE-mediated cytolysis; and 3) Examine in vivo the pharmacokinetics, efficacy, and toxicity of CPE therapy. Upon completion of this project, we will be positioned to quickly translate this research into a novel clinical treatment for patients with chemotherapy-resistant disease. Ovarian carcinoma remains the most lethal of gynecologic malignancies, with up to 90% of patients diagnosed with advanced stage ovarian cancer dying from recurrent chemotherapy-resistant tumors; therefore, development of novel therapies for this disease is a high priority for improving public health. Results of the proposed research will lay the foundation for rapid clinical translation of an innovative, potentially highly effective treatment for patients with chemotherapy-resistant ovarian cancer.