中文摘要
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。
英文摘要
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.
结题摘要
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。通过近4年的一系列研究,我们发现:(1) PPG具有逆转大肠癌LoVo/Adr细胞MDR的特性。(2) PPG对P-GP基因的基因水平及蛋白表达均无影响,但可以明显降低bcl-2及PTEN基因的表达。bcl-2基因与细胞的凋亡有关,而PTEN基因为自噬调控的上游分子。 (3) PPG可显著降低MDR细胞株LoVo/Adr细胞内pH值,恢复细胞的敏感性,(4) 在静息状态下,PPG可显著降低LoVo/Adr细胞内Ca2+ 浓度,也说明耐药肿瘤细胞确实存在着Ca2+浓度的变化,PPG逆转耐药可能是改变Ca2+离子通道所致。(5)在耐药的LOVO/ADR细胞中加入PI103作用后,Akt、PI3K 、P-AKT表达均下降,与对照组相比,并未引起Akt、PI 3K、P-AKT表达下降,说明了苯丙素苷化合物是不影响mTOR上游信号通路的。(6)苯丙素苷化合物 引起下游P70S6 K 、S6K1、p-S6K1、 4E-BP1及 p-4E-BP1分子表达减少。说明苯丙素苷具有抑制mTOR分子下游通路的作用。初步可得出以下几点结论:1、PPG可显著降低MDR细胞株LoVo/Adr细胞内pH值,恢复细胞的敏感性;2、PPG可显著降低LoVo/Adr细胞内Ca2+ 浓度,逆转耐药可能是改变Ca2+离子通道所致。3、苯丙素苷引起耐药细胞发生自噬和凋亡发生逆转耐药。 4、苯丙素苷不能抑制mTOR分子上游通路而起作用。5、苯丙素苷可能通过直接抑制mTOR分子及下游通路相关分子的表达而引起细胞自噬发生。科学意义:PPG逆转大肠癌MDR与调控细胞内PH值及Ca通道有关,同时PPG可通过 mTOR信号通路逆转大肠癌MDR,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,具有重要的现实意义。
