具有多重活性的新型法尼基硫代水杨酸衍生物的合成、抗肿瘤活性及其机制研究

Mutation and activation of Ras proto-oncogene play key role in the formation and progression of human malignant tumors. Farnesylthiosalicylic acid (FTA), as a novel Ras inhibitor in clinical trial, could block Ras-related downstream signaling pathway and induce tumor cells apoptosis. However, its therapeutic efficacy is limited, and usually requires the therapeutic combination with other anti-cancer drugs. It is known that combined medication of FTA and pyrimidine nucleosides could increase the tumor cells' sensitivity to medicine and facilitate its apoptosis. Meanwhile, the conjugates coupling the long farnesyl-chain of FTA with the pyrimidine nucleoside at the N4 or 5' position could improve the lipophilic of nucleosides, enter cells easily by passive diffusion, inhibit DNA synthesis and decrease drug resistance in cancer cells. Furthermore, NO donor diazeniumdiolate can selectively kill tumor through targeted releasing high levels of NO in cancer cells. Novel FTA/nucleosides conjugates and their NO-releasing derivatives with multiple activities will be designed and synthesized with the expectation that they could inhibit Ras and DNA synthesis related enzymes and display NO-mediated anticancer activities. Their anti-tumor activities both in vitro and in vivo, structure-activity relationships, and their selective effects on the corresponding targets will be evaluated, and the mechanism of underlying the anticancer activity and pharmacokinetics of these active derivatives will be studied with the best expectation that a promising antitumor candidate compound with high efficacy and low toxicity will be discovered by our effort for future preclinical research.

Ras原癌基因的突变、激活是恶性肿瘤形成与发展的关键因素之一。临床研究的Ras抑制剂法尼基硫代水杨酸（FTA）虽能抑制Ras下游信号通路，并诱导其凋亡，但其抗肿瘤活性有限，常要与其它抗癌药联合用药。鉴于FTA与核苷类药物联合用药后，能增加肿瘤细胞对药物的敏感性，促进其凋亡；同时考虑到将FTA长链酰基引入嘧啶核苷的N4或5'位，可提高核苷类药物亲脂性，使其被动扩散进入细胞，抑制肿瘤DNA合成，降低肿瘤细胞的耐药性；另考虑到偶氮鎓二醇盐类NO供体能靶向释放高浓度的NO，可选择性杀伤肿瘤；本项目设计、合成具有多重作用的FTA-核苷缀合物及其NO供体衍生物，期望它们抑制Ras信号通路和DNA合成的相关酶，并具有NO介导的抗肿瘤活性。通过测定目标物体内外抗癌活性，分析构效关系，考察其对相应靶标的选择性，研究其作用机制和初步药代动力学，希望获得高效、低毒且优于FTA的新型抗肿瘤药物进入临床前研究。

Ras致癌基因的突变、激活是人类恶性肿瘤形成与发展的关键因素之一，Ras抑制剂法尼基硫代水杨酸（FTA）虽能抑制Ras下游信号通路，并诱导其凋亡，但其抗肿瘤活性有限，临床上常与其它抗癌药联合用药。本项目以FTA为先导化合物，针对临床核苷类药物吉西他滨（Gemcitabin）的缺陷以及它与FTA的临床协同治疗作用，设计、合成了35个结构新颖的具有多重作用的FTA-核苷缀合物及其NO供体衍生物，并采用核磁共振氢谱、碳谱、质谱、红外光谱、元素分析等技术进行了结构表征，对上述设计目标物进行体外的抗肿瘤活性和片段之间的协同抗肿瘤活性测试，研究NO释放量与抗肿瘤活性之间的关系，分析目标化合物的构效关系，研究活性化合物诱导肿瘤细胞凋亡和细胞周期阻滞作用，研究Ras相关下游信号通路抑制作用，以及从前药角度研究目标化合物的稳定性、体内急性毒性、初步药物代谢动力学以及体内抗肿瘤活性。研究结果显示：本课题所设计的化合物具有显著的体内外抗肿瘤效果，前药FTA-Gem的体内抗肿瘤活性比原药gemcitabin明显增强，且极性毒性却低于原药gemcitabin近5倍。通过体内初步药物代谢动力学研究显示，前药FTA-Gem在体内缓慢释放出原药FTA和gemcitabin，显著增加体内原药FTA和gemcitabin的血药浓度，并且发挥FTA和gemcitabin之间的协同抗肿瘤作用，同时有效减少gemcitabin被脱氨酶失活，极大地提高gemcitabin口服生物利用度。上述活性研究充分验证了本课题所设计化合物具有高效、低毒且优于临床FTA和gemcitabin的新型抗肿瘤化合物，将进一步对不同系列化合物进行深入活性和成药性研究，为进一步将其开发成为具有我国自主知识产权的新药奠定坚实基础。在该课题创新成果支持下，获得了3项相关授权发明专利，申请了2项发明专利；在药物化学学术期刊上发表了9篇SCI文章；同时该课题所属系统项目“具有多重活性的新型法尼基硫代水杨酸衍生物的研究与开发”获得2015年南通市科技进步二等奖。