岭南中药蒲葵抑制细胞自噬协同化疗预防癌症骨转移的药效物质基础及机制研究

Cancer bone metastasis is a common complication of malignant tumor. During the process of the bone metastasis, cancer cells are adapted to the change of microenvironment and develop resistance to chemotherapy through occurring protective autophagy. Also, the cancer cells which contain a large number of drugs through autophagosome, show strong toxic effects by inhibiting the middle and the late periods of autophagy. Hence, looking for agents with inhibiting the middle and the late periods of autophagy synergy with anticancer drugs is one of the most promising strategies to prevent cancer bone metastasis. In our previous work, we found benzofuran compounds isolated from Livistiona chinensis can significantly inhibit autophagy of highly metastatic breast cancer cells and improve the susceptibility of cell apoptosis induced by drug taxol. Furthermore, it is verified that this inhibiting activity is realized by inhibiting the middle and the late periods of autophagy. In our continuing research, we continue to systematically isolate benzofuran compounds from Livistona chinensis, to elucidate their structures, and to evaluate their bioactivities that inhibit autophagy of highly metastatic breast cancer cells and improve the susceptibility of cell apoptosis induced by drug taxol. Subsequently, we will analyse the in vitro activity of the major bioactive compounds to obtain the target compounds for further research and clarify the mechanism of the target compounds. Meanwhile, we will enrich the active compounds and establish the quality control standard of active richment that can prevent cancer bone metastasis synergy with anticancer drug taxol. Finally, this research will provide the basis for the discovery and development of lead compounds and drugs from Livistona chinensis as a new type of preventing cancer bone metastasis synergy with anticancer drug taxol.

癌症骨转移是恶性肿瘤的并发症。肿瘤细胞在骨转移过程中通过保护性自噬来适应微环境变化和对化疗产生耐药性，而抑制肿瘤细胞自噬中晚期能使已通过自噬小体包裹大量药物的细胞产生强烈的毒性作用。通过寻找自噬中晚期抑制剂协同药物以此预防骨转移已成为当前骨转移预防的新策略。在我们前期研究中，首次发现蒲葵苯并呋喃能显著抑制紫杉醇诱导易转移乳腺癌细胞自噬而提高癌细胞凋亡敏感性，并发现该抑制作用是通过抑制癌细胞自噬中晚期实现的。本项目拟在前期基础上，进一步对苯并呋喃成分系统分离和鉴定，并评价其协同紫杉醇诱导癌细胞凋亡和抑制紫杉醇诱导癌细胞自噬活性，筛选出强活性化合物，在此基础上对强活性化合物进行体内协同紫杉醇预防癌症骨转移活性和作用机制研究；同时，富集活性化合物，制定活性富集物协同紫杉醇预防癌症骨转移的质量控制标准，最终为从蒲葵籽中开发协同紫杉醇预防癌症骨转移活性先导化合物和药物提供科学依据。

癌症骨转移是恶性肿瘤的并发症。肿瘤细胞在骨转移过程中通过保护性自噬来适应微环境变化和对化疗产生耐药性，而抑制肿瘤细胞自噬中晚期能使已通过自噬小体包裹大量药物的细胞产生强烈的毒性作用。通过寻找自噬中晚期抑制剂协同药物以此预防骨转移已成为当前骨转移预防的新策略。本项目进一步对蒲葵、金银花、紫草等中药的化学成分进行了系统分离和鉴定，从蒲葵、金银花、紫草等植物中分离鉴定出300多个化合物；并评价其协同紫杉醇诱导癌细胞凋亡和抑制紫杉醇诱导癌细胞自噬活性，筛选出5个强活性化合物；在此基础上对2强活性化合物进行体内协同紫杉醇预防癌症骨转移活性和作用机制研究；发现：（1）化合物JNU-144抑制丝氨酸-苏氨酸蛋白激酶mTOR活性，从而抑制肿瘤细胞的生长增殖；促进肿瘤细胞发生由线粒体途径介导的细胞凋亡；通过调控EMT相关蛋白表达量抑制肿瘤细胞的侵袭迁移活力。（2）蒲葵苯丙呋喃HDAB抗癌作用机制主要包括以下几个方面：化合物HDAB具有很强的体外抑制Hela细胞增殖和抑制Hela细胞克隆形成的活性；HDAB对宫颈癌实体瘤的抑制率为43.87±5.12%，提示HDAB具有良好的抗宫颈癌活性；HDAB通过促进癌细胞凋亡达到抗癌效果的；HDAB通过ATM通路诱导Hela细胞周期阻滞在S期和DNA损伤后修复；通过Westen blotting、体外酶活抑制实验、计算机模拟实验发现HDAB能够抑制PARP表达和活性，HDAB为PARP酶抑制剂。