苯丙素苷化合物通过mTOR信号通路逆转大肠癌多药耐药的分子机制

The produce of multidrug resistance (MDR) is main reason for chemotherapy failure or efficacy reducing on colon carcinoma. Choosing reversal agents which are more target point, low price and anticancer activity from among traditional Chinese Medicine is our advantage. Phenypropanoid glycosides (PPG) which is capable of anticoagulation antioxidant and anticancer is one of extract from pedicularisL. We discovered PPG revering MDR mechanisms was by inducing apotosis, and increase uptake and nucleus accumulation of drug in MDR cells. The mTOR signal pathway is key part regulating apotosis, Another experiment of us proved that multidrug resistance was revesing by mTOR signal pathway enhancing autophagy and apotosis,decreasing expression of mdr1 gene. therefore, We infered PPG might reversing MDR by mTOR signal pathway.The project aims is to study the reverse mechanism of PPG in depth and observe to influence of PPG on signal moleculars active of upper and lower in mTOR pathway, authphagy, apotosis and multidrug resistance genes by PPG. We will clarify the molecular mechanism on PPG reversing MDR by mTOR pathway in LoVo/Adr cell. The researcher results will help to provide to theoretical basis and experimental support for PPG which is as a potential mTOR pathway inhibitor reversing MDR of colon carcinoma.

多药耐药（MDR）的产生是大肠癌化疗效果明显下降或失败的主要原因，从传统中药中筛选出低毒、作用靶点广泛、价格低廉、具有抗癌活性的逆转剂是我们的优势所在。马先蒿提取物之一苯丙素苷化合物（PPG）具有抗凝、抗氧化、抗癌的作用。我们前期实验发现PPG具有逆转大肠癌MDR的特性，其逆转途径可能与增加耐药细胞对药物的摄入及核区积聚、促进凋亡有关，另一组实验也证实：抑制mTOR通路可促使耐药细胞自噬及凋亡、减少mdr1基因表达而逆转MDR，逆转途径均与凋亡有关，而mTOR通路是调控凋亡的核心环节,故推测PPG可能通过mTOR信号通路逆转MDR。因此，本课题进一步深入PPG逆转机制，通过观察PPG对mTOR信号通路上下游不同靶点信号分子活性、自噬、凋亡的影响，旨在阐明PPG通过mTOR通路逆转大肠癌LoVo/Adr细胞多药耐药的分子机制，为PPG可能作为mTOR通路抑制剂，靶向治疗大肠癌MDR提供理论依据。

苯丙素苷化合物（PPG）为中草药马先蒿中分离的天然产物，我们研究发现具有逆转大肠癌多药耐药（MDR）的特性，本课题进一步深入PPG逆转机制，通过观察PPG对mTOR信号通路上下游不同靶点信号分子活性、自噬、凋亡的影响，旨在阐明PPG通过mTOR通路逆转大肠癌LoVo/Adr细胞多药耐药的分子机制。主要研究内容：1、确定PPG逆转逆转大肠癌LoVo/Adr细胞多药耐药，计算耐药指数及逆转倍数。2、 PPG逆转耐药过程中对耐药相关基因P-gp、凋亡相关基因bcl-2、PTEN基因的表达的影响。3、判断PPG引起自噬可能所涉及的mTOR通路途径。4、PPG逆转多药耐药与凋亡基因bcl-2、PTEN基因有关，探讨PPG对凋亡的影响。研究结果表明：1、PPG具有逆转多药耐药的特性，PPG 20 mɡ/L，PPG40 mɡ/L时的逆转倍数分别为5.24和 9.78。2、PPG可能是通过引起耐药细胞发⽣⾃噬和凋亡机制⽽逆转耐药。3、PPG诱导细胞⾃噬主要是通过mTOR通路实现的。4、PPG不能抑制mTOR分⼦上游通路而起作⽤、⽽是通过直接抑制mTOR分⼦及下游信号通路之⼆S6K1信号传导通路诱导细胞⾃噬发⽣。5、PPG诱导细胞⾃噬可能主要是调控了⾃噬的形成阶段。6、PPG具有诱导多药耐药凋亡的作⽤，可能与bcl-2及PTEN基因调控有关。科学意义：本研究说明了 PPG 通过mTOR 信号通路诱导⾃噬发⽣和通过bcl-2及PTEN基因诱导凋亡逆转⼤肠癌 MDR。为 PPG可能作为mTOR 通路抑制剂，靶向治疗⼤大肠癌 MDR 提供理论依据，具有重要的现实意义。