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

描述（申请人提供）：卵巢癌仍然是妇科肿瘤中死亡率最高的癌症。虽然许多卵巢癌患者对手术和化疗的标准组合完全有反应，但近90%的患者后来发展为复发性化疗耐药癌症，并不可避免地死于疾病。因此，开发针对复发性/化疗耐药性卵巢癌的创新有效疗法仍然是改善公共卫生的高度优先事项。使用高通量技术分析卵巢癌的遗传指纹，我们最近发现了编码蛋白claudin-3和claudin-4的基因的极高表达。由于claudin-3和claudin-4是产气荚膜梭菌肠毒素（CPE）的上皮受体，并且足以介导CPE结合，从而引发随后的毒素介导的细胞溶解，因此我们假设基于其高水平的claudin-3和claudin-4使用CPE靶向卵巢癌细胞可能是一种用于化疗耐药卵巢癌的新型高效治疗方法。与这一观点一致，我们将CPE引入了从过表达claudin-3和claudin-4的几种原发性、转移性和化疗耐药卵巢癌中培养的细胞中，我们发现这些肿瘤细胞与健康人体组织不同，对CPE介导的细胞溶解高度敏感。更重要的是，我们发现，对具有高度相关的化疗耐药人卵巢癌临床模型的SCID小鼠异种移植物进行腹腔内CPE治疗，可以抑制100%患有1周确诊疾病的小鼠的肿瘤生长。因此，使用CPE靶向高水平的密蛋白-3和-4可能代表了一种创新的、潜在的高效治疗方法，以杀死转移性和/或化疗抗性卵巢癌细胞。因此，该提议具有三个相关的具体目标：1）表征卵巢癌中密蛋白-3和密蛋白-4的表达的概况和调节; 2）表征卵巢癌细胞对CPE介导的细胞溶解的敏感性和抗性;以及3）在体内检查CPE疗法的药代动力学、功效和毒性。该项目完成后，我们将能够迅速将这项研究转化为针对化疗耐药疾病患者的新型临床治疗方法。卵巢癌仍然是最致命的妇科恶性肿瘤，高达90%的晚期卵巢癌患者死于复发性化疗耐药肿瘤;因此，开发这种疾病的新疗法是改善公共卫生的高度优先事项。这项研究的结果将为快速临床转化一种创新的、潜在的高效治疗化疗耐药卵巢癌患者的方法奠定基础。

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.