基于膀胱癌转基因动物模型中药石斛毛兰素的化学预防与分子靶点机制

Bladder cancer is the most common malignant tumor of the urinary system in China and so far limited success has been achieved in extending the survival of patients. JNK signal transduction pathway is closely related with the Programmed cell death, and apoptosis plays a fundamental role in animal development and tissue homeostasis. Abnormal regulation of apoptosis is associated with a wide variety of human diseases including cancer, immunological and developmental disorders and neurodegeneration. Previous data have clearly showed the anti-tumor potential of Erianin from traditional Chinese medicine Dendeobius extracts. However, the appropriate anti-cancer efficacy of Erianin that acts as an ideal molecular probe in bladder cancer, as well as the direct binding target identification and the profound molecular mechanism of signaling regulatory pathway are still poorly understood. Our proposal is to investigate the anti-cancer activity of Erianin, especially to evaluate the in vivo efficacy in bladder cancer by using transgenic mice which the urothelial expression of SV40T antigen or Ha-ras-M was initiated by a urothelium-specific promoter of the uroplakin II gene. More importantly, the molecular target and mechanism of apoptosis by Erianin will be further investigated by modern biological technologies combined with the proteomics, chemical biology and pharmacology research tools respectively. Furthermore, the direct protein target and molecular regulatory mechanism involved in JNK/c-Jun signaling pathway by Erianin are necessary to be elucidated by using a novel DNA-programmed photoaffinity labeling technology. Taken together, our goal is to provide the new evaluation system for the discovery of potential reagent for cancer chemoprevention, to identify the direct binding protein of small molecule, to further investigate the new regulatory mechanism of apoptotic pathway mediated by the novel protein target, and finally to lay the firm foundation for the discovery and optimization of molecular targeted anticancer drugs.

膀胱癌发病机制复杂，目前尚缺有效治愈药物。中药石斛活性成分毛兰素能诱导多种恶性肿瘤细胞的凋亡，但其对膀胱癌发生发展的化学预防效能、直接分子靶标以及深入的分子调控机制仍知之甚少。本项目结合目前的研究现状，拟在前期工作基础上，建立组织特异性UPII/SV40T、UPII/Ha-ras-M膀胱癌转基因小鼠模型，理想地模拟浸润性上皮细胞癌与浅表性乳头状移行细胞癌两种膀胱癌主要临床病理类型特征，从分子、细胞、动物层次研究小分子探针毛兰素的抗癌活性及其分子机制，建立基于膀胱癌化学预防潜能的中药活性物质的抗癌活性评价体系，通过DNA编程光亲和标记等技术分离、鉴定毛兰素的直接作用靶蛋白，以此为突破口，进而阐明其分子靶点介导JNK/c-Jun信号通路诱导细胞凋亡上下游的分子调控新机制，对于揭示膀胱癌癌变的分子机制以及基于新靶点的化学预防与抗肿瘤创新中药的研发具有重要价值。

膀胱癌发病机制复杂，目前尚缺有效治愈药物。中药石斛活性成分毛兰素能诱导多种恶性肿瘤细胞的凋亡，但其对膀胱癌发生发展的化学预防效能、直接分子靶标以及深入的分子调控机制仍知之甚少。我们通过研究发现毛兰素通过线粒体凋亡和JNK信号通路诱导膀胱癌细胞的增殖，在体外和动物体内表现出良好的抗肿瘤作用；研究了毛兰素的构效关系，发展了基于光交联亲和标记的蛋白质表达谱的靶点识别技术，分离鉴定了毛兰素的靶点为丙酮酸羧化酶；发现了(−)-Gochnatiolide B通过凋亡通路抑制膀胱癌细胞的增殖，在体外和动物体内表现出良好的抗肿瘤作用；发现了10-氯铁屎米酮通过激活Bim介导的线粒体凋亡通路抑制卵巢癌细胞的增殖。这些研究从不同角度阐明了JNK/c-Jun信号通路诱导细胞凋亡上下游的分子调控新机制，对于揭示膀胱癌癌变的分子机制以及基于新靶点的化学预防与抗肿瘤创新中药的研发具有重要价值。