Development of novel gene therapy based on the analysis of anti-apoptotic signals in ovarian cancer

在妇科恶性肿瘤中，卵巢癌最常与化疗耐药及预后不良相关。包括顺铂在内的多种抗癌药物的化疗效果是由细胞内凋亡信号介导的。抗凋亡因子，无论是外在的还是内在的，都可能影响化疗效果，并可能导致卵巢癌细胞的化疗耐药。因此，我们的研究目的是分析卵巢癌细胞的抗凋亡信号，并针对这些抗凋亡信号开发新的基因治疗。我们的研究表明，大约一半的卵巢癌在mRNA和蛋白水平上表达LH/hCG受体。在表达LH/hCG受体的卵巢癌细胞系OVCAR3中，hCG通过上调IGF-1抑制顺铂诱导的细胞凋亡。IGF-1还能抑制顺铂诱导的细胞凋亡，IGF-1受体中和抗体可恢复细胞凋亡。Wortmannin是一种磷脂酰肌醇3-激酶抑制剂，可阻断IGF-1的抗凋亡作用。因此，促性腺激素是卵巢癌细胞抗凋亡信号的重要外源性因子。用表达反义IGF-1 mRNA的重组腺病毒治疗可有效恢复顺铂诱导的细胞凋亡。肿瘤抑制基因p53异常存在于半数以上的卵巢癌中。促凋亡bax基因受p53调控，p53异常导致化疗耐药是一种内在的抗凋亡因子。在体外，与顺铂敏感的A2780 （p53野生型）相比，Bax蛋白在顺铂耐药细胞系(如A2780/cDDP （p53突变）和SKOV3 （p53缺失）中表达减弱。我们开发了高表达Bax蛋白的重组腺病毒。通过Bax/腺病毒转染成功诱导Bax蛋白，并在顺铂耐药卵巢癌细胞中获得凋亡效应。因此，腺病毒介导的Bax导入可能是治疗化疗耐药卵巢癌的一种有用的基因疗法。少

Among the gynecological malignant tumors, ovarian carcinoma is most frequently associated with chemoresistance and poor prognosis of the patients. The effect of chemotherapy with various anti-cancer agents including cisplatin is shown to be mediated by intracellular apoptotic signals. Anti-apoptotic factors, either extrinsic or intrinsic, may influence the chemotherapeutic effect, and may result in the chemoresistance of ovarian cancer cells. Therefore, the objective of our study is to analyze the anti-apoptotic signals in ovarian carcinoma cells, and to develop novel gene therapy targeting these anti-apoptotic signals.Our study demonstrated that an approximately half of ovarian carcinomas expressed LH/hCG receptor at both mRNA and protein levels. In ovarian cancer cell line OVCAR3 expressing LH/hCG receptors, hCG inhibited cisplatin-induced apoptosis via up-regulation of IGF-1. IGF-1 also inhibited cisplatin-induced apoptosis and a neutralizing antibody to IGF-1 receptor restored the … More apoptosis. Wortmannin, an inhibitor of phosphatidyl inositol 3-kinase, blocked the anti-apoptotic effect of IGF-1. Therefore, gonadotropin is an important extrinsic factor of anti-apoptotic signal in ovarian cancer cell. Treatment with recombinant adenovirus expressing anti-sense IGF-1 mRNA was effective for restoring the cisplatin-induced apoptosis.Abnormality of p53 tumor suppressor gene is present in more than half of ovarian carcinomas. Pro-apoptotic bax gene is under the regulation of p53, and p53 abnormality resulted in chemoresistance as an intrinsic anti-apototic factor. In vitro, Bax protein expression was attenuated in cisplatin-resistant cell lines such as A2780/cDDP (p53 mutated) and SKOV3 (p53 deleted), compared with cisplatin-sensitive A2780 (p53 wild type). We developed recombinant adenovirus which highly expresses the Bax protein. The Bax protein was successfully induced by treatment with the Bax/adenovirus transfer, and apoptotic effect was obtained in the cisplatin-resistant ovarian cancer cells. Therefore, adenovirus-mediated introduction of Bax may be a useful gene thrapy in the treatment of chemoresistant ovarian carcinomas. Less