Novel Polyamine-conjugated Dendrimers for Pretargeted Chemotherapy of Ovarian Can

描述（申请人提供）：背景：卵巢癌是女性癌症死亡的第四大常见原因，在妇科恶性肿瘤中排名第二，占美国女性所有癌症的4%。卵巢癌的一线化疗包括顺铂-紫杉醇联合治疗。然而，这些药物伴随着严重的毒副作用，例如顺铂显示神经毒性、肾毒性和呕吐，限制了它们的使用。约75%的晚期卵巢癌患者对常规治疗无反应，这要么是由于对化疗产生耐药性，要么是由于残留病灶治疗无效。因此，本建议旨在通过使用树枝状聚合物作为用于腹膜内递送顺铂的载体的多步靶向方法来有效地根除或控制这些微肿瘤。基本原理：我们提出了一种新的治疗策略，可以作为现有卵巢癌治疗主要模式的辅助治疗，以延长卵巢癌患者的寿命并改善其生活质量。我们的策略涉及施用对卵巢癌相关抗原（CA-125）和生物素都具有特异性的双特异性抗体。双特异性抗体结合肿瘤表面。该步骤之后是施用载药的生物素化的多胺缀合的树枝状聚合物以将药物靶向癌细胞。预靶向策略向先前由双特异性抗体靶向的肿瘤提供高剂量的药物，从而产生更好的功效和降低的毒性。研究设计：双特异性抗体将通过化学交联制备，并通过柱色谱法纯化。双特异性抗体的纯度将通过SDS PAGE测试，并且免疫反应性将通过使用ELISA和共聚焦显微镜的OVCAR-3细胞的结合研究测试ii）肿瘤细胞摄取双特异性抗体的动力学将通过共聚焦显微镜进行iii）通过EDC偶联反应将多胺偶联到树枝状大分子的羧基末端，并测试其载药效率iv）在NIH OVCAR-3裸鼠中评价预靶向策略。相关性：晚期卵巢癌患者的5年生存率仅为44%。我们提出了一种有效的治疗策略，以增加这些晚期卵巢癌患者，并提高他们的生活质量。这种新方法减少了与用于卵巢癌治疗的化疗药物相关的毒副作用。

DESCRIPTION (provided by applicant): Background: Ovarian cancer is the fourth most frequent cause of cancer death among women and it ranks second among the gynecological malignancies accounting 4% of all cancers in women in United States.. The first line of chemotherapy for ovarian cancer comprises of cisplatin-paclitaxel combination therapy. However, these drugs are associated with severe toxic side effects, for instance, cisplatin shows neurotoxicity, nephrotoxicity and emesis, limiting their usage. About 75% of the late stage ovarian cancer patients do not respond to the conventional therapy either due to development of resistance to chemotherapy or the inefficient treatment of the residual disease. Therefore, the present proposal aims at efficiently eradicating or controlling these micro tumors by a multistep targeting approach using dendrimers as carriers for the intraperitoneal delivery of cisplatin. Rationale: We propose a novel therapeutic strategy that could serve as an adjunct therapy to the existing primary modes of the ovarian cancer therapyto increase the life span and to improve the quality of life of the ovarian cancer patients. Our strategy involves administration of the bispecific antibodies with specificity for both Ovarian cancer associated antigen (CA-125) and biotin. The bispecific antibody binds to the tumor surface. This step is followed by the administration of drug loaded biotinylated, polyamine conjugated dendrimers to target the drug to the cancer cells. The pretargeting strategy provides high dose of the drug to the tumors previously targeted by the bispecific antibody resulting in better efficacy and reduced toxicity. Research Design: The bispecific antibodies will be prepared by chemical cross linking and they will be purified by Column chromatography. The purity of the bispecific antibody will be tested by SDS PAGE and the immunoreactivity will be tested by binding studies with OVCAR-3 cells using ELISA and Confocal microscopy ii) Kinetics of the uptake of bispecific antibodies by the tumor cells will be perfdormed by Confocal microscopy iii) Polyamines will be conjugated to the carboxy terminals of the dendrimers by EDC coupling reaction and their efficiency of drug loading will be tested by HPLC method iv)The pretargeting strategy will be evaluated in NIH OVCAR-3 nude mice. Relevance: The Five year survival rate of the late stage ovarian cancer patients is only 44%. We propose an efficient treatment strategy to increase these late stage ovarian cancer patients and also to improve their quality of life. This novel approach reduces the toxic side effects associated with the chemotherapeutics used for the ovarian cancer treatment.