不同结构类型C21甾体类化合物逆转肿瘤多药耐药构效关系与作用机制研究

Chemotherapy is one of the most important methods used to treat cancer. However, multdrug resistance (MDR) during chemotherapy is the leading cause of treatment failure and decreased survival in cancer patients. As a program screening new reversal agents of cancer cell MDR from Chinese herbal medicines, C21 steroidal hydrolysis from Marsdenia tenacissima was found of the ability to increase the cytotoxicity and intracellular uptake of chemotherapeutic drug adriamycin in drug-resistant human gastric cancer cell line SGC7901/VCR. Twenty-two C21 steroidal derivatives including thirteen new compounds have been isolated from the hydrolysis and eight of them have been evaluated for their potential reversal activity. On the basis of previous research, the structure-reversal activity relationships between different types of C21 steroids on multidrug resistance in cancers and mechanisms will be investigated. The different types of C21 steroidal aglycones and their derivatives will be isolated and identified from Metaplexis japonica, M. tenacissima, Cynanchum inamoenum, and C. ascyrifolium. The MDR reversal activities will be evaluated on drug sensitivities of adriamycin, vincristine, 5-fluorouracil, and cisplatin in three kinds of MDR human cancer cells in the presence of each compound. The mechanistic experiments of high effective compounds will be conducted to examine the effects on cell cycle, ATPase, intracellular accumulation of adriamyrin, intracellular accumulation of rhodamin123, expression of P-glycoprotein, expression of MDR1-mRNA. The study benefits will provide theoretical basis to develop new drug possessing self-governed intellectual property. The research is important both theoretically and practically.

化疗是恶性肿瘤综合疗法的方法之一，而肿瘤多药耐药（MDR）严重影响化疗的疗效。在前期工作的基础上，本研究选择含有基本涵盖不同结构类型C21甾体类化合物的四种萝藦科植物（萝藦、通光散、竹灵消、潮风草），分离鉴定不同结构类型C21甾体苷元与其不同取代基衍生物；采用MTT法测定分离鉴定化合物对肿瘤耐药细胞株耐药性的逆转作用，探索不同结构类型C21甾体类化合物结构与逆转作用之间的关系，不同取代基与逆转作用之间的关系，寻找高活性化合物；采用细胞分子生物学技术手段研究高活性化合物对肿瘤耐药细胞株细胞周期、P-gp蛋白表达、多药耐药基因MDR1转录、ATP酶活性、药物转运功能的影响，阐明其作用机制。本研究为开发具有自主知识产权的高效低毒逆转肿瘤多药耐药创新药物奠定基础，具有重要的学术价值和应用前景。

化疗是恶性肿瘤综合疗法的方法之一，而肿瘤多药耐药（MDR）严重影响化疗的疗效，本研究旨在从天然植物资源中寻找逆转肿瘤多药耐药活性化合物。采用现代提取分离鉴定技术从四种萝藦科植物分离鉴定了不同结构类型C21甾体苷元与其不同取代基衍生物89个，包括41个C21甾体类新化合物：潮风草苷A-G，新潮风草苷元A-B，新白薇苷元I-F，白前苷元F-G，新萝藦苷元A-D，徐长卿苷F-G，新徐长卿苷A-D，12β-O-谷酰基苯丙氨酰基-3β,7β,14β,17β-四羟基-孕甾-5-烯-20-酮，3-O-β-D-吡喃洋地黄毒糖基-(1→4)-β-D-吡喃磁麻糖-12β,14β,17β-三羟基-孕甾-4,6-二烯-20-酮，通光藤苷元A和B衍生物12个。采用MTT法测定分离鉴定化合物对肿瘤耐药细胞株耐药性的逆转作用，13,14:14,15-二裂环孕甾烷衍生物白前苷元A 3-O-β-D-吡喃磁麻糖苷、白前苷元C 3-O-β-D-吡喃夹竹桃糖苷、白前苷元A 3-O-β-D-吡喃洋地黄毒糖基-(1→4)-β-D-吡喃磁麻糖苷、白前苷元A 3-O-β-D-吡喃夹竹桃糖苷、新白薇苷元F 3-O-β-D-吡喃夹竹桃糖苷潜在逆转人结肠癌耐药细胞株HCT-8/VCR对ADM耐药作用，单糖苷活性强于双糖苷，双糖苷强于苷元，；通光藤苷元B孕甾烷衍生物11α-O-顺芷酰基-12β-O-乙酰基-通光藤苷元B，11α-O-2-甲基丁酰基-12β-O-乙酰基-通光藤苷元B，11α,12β-O-双顺芷酰基-通光藤苷元B，11α-O-2-甲基丁酰基-12β-O-顺芷酰基-通光藤苷元B潜在逆转人胃癌多药耐药细胞株SGC7901/VCR对ADM耐药作用，11α和12β酰基取代增强逆转人胃癌多药耐药细胞株SGC7901/VCR对ADM耐药作用。采用细胞分子生物学技术手段研究高活性化合物白前苷元A 3-O-β-D-吡喃磁麻糖苷和白前苷元C 3-O-β-D-吡喃夹竹桃糖苷对肿瘤耐药细胞株细胞周期、P-gp蛋白表达、多药耐药基因MDR1转录、ATP酶活性、药物转运功能的影响，白前苷元A 3-O-β-D-吡喃磁麻糖苷和白前苷元C 3-O-β-D-吡喃夹竹桃糖苷增加阿霉素累积和罗丹明123在人结肠癌耐药细胞株HCT-8/VCR蓄积。本研究为开发具有自主知识产权的高效低毒逆转肿瘤多药耐药创新药物奠定基础，具有重要的学术价值和应用前景。