合欢皮总皂苷抗肿瘤作用靶点鉴定与分子机制解析

Anti-tumor target identification and molecular mechanism study of total saponins from Albizia julibrissin

合欢皮作为常用中药,临床常用于治疗失眠、焦虑、肿瘤等。现代药理中针对合欢皮总皂苷(TSAJ)抗肿瘤活性多有报道,但由于单体成分分离困难,药理机制难以开展。该研究采用MTT法和Hoechst 33258染色法,确认了TSAJ对肝癌细胞的生长抑制作用,构建了表面修饰有TSAJ的固相亲合微球,利用该固相微球特异性地从人肝癌细胞裂解液中富集靶点蛋白,再利用高分辨质谱对富集到的靶点蛋白进行鉴定。采用Matabo Analyst 3.0处理数据,筛选并确定了Exportin-2,Beta-actin-like protein 2,Myosin-9,Protein transport protein Sec61 subunit beta,Cytochrome c oxidase copper chaperone等5个靶点蛋白。这些蛋白分别具有调控细胞凋亡及细胞生长、分化、运动等功能,提示TSAJ的抗肿瘤机制可能与诱导细胞凋亡及抑制肿瘤血管生成有关。综上所述,该研究利用TSAJ修饰的固相亲和微球,特异性富集并鉴定了TSAJ的靶点蛋白,从靶点源头上解释了TSAJ抗肿瘤作用机制,同时也为中药复杂体系的分子药理机制研究提供了一种全新的思路。

Dried stem bark from Albizia julibrissin（ AJ） is a common traditional Chinese herb with several therapy effects including insomnia,anxiety and anti-tumor. Recently,the anti-tumor effect and mechanism studies of AJ have drawn much attention; however,there are still some troubles in chemical composition separation,which leads to the difficulties in pharmacological research of AJ. In this study,we firstly confirmed the proliferation inhibitory effect of total saponins from AJ（ TSAJ） on human hepatocarcinoma（ Hep G2）cells,and also tested the apoptosis induction effect of TSAJ. Then,we successfully captured the potential target proteins from Hep G2 lysates by using TSAJ-modified solid beads,and identified the target proteins by LC-MS/MS. Finally,we confirmed 5 target proteins including Exportin-2,Beta-actin-like protein 2,Myosin-9,Protein transport protein Sec61 subunit beta,and Cytochrome c oxidase copper chaperone,which are responsible forcell apoptosis,proliferation,differentiation andmigration. In summary,our findings elucidate the potential anti-tumor mechanism of TSAJ from the direct target proteins,and provide a new insight for exploring the pharmacological mechanism of traditional Chinese medicine.