TWIST在胃癌多药耐药中的作用及分子机制

TWIST is one of the bHLH tanslating infactor family.Recent studes show that TWIST may contribut to various properties of tumnor cells ,for example induction of tumorigenesis, promotion of invasion and metasis.TWIST was also discovered play a role in multi-drug resistance of tumor cells.To date, however, the data on the role of TWIST in the MDR of gastric cancer are still unclear.The multidrug resistanc of gastric cancer is the one of the main cause for failed chemiotherapy.But there is no useful method toreverse it. In the Our earlier study indicated the up-regulation of TWIST protein was observed in gastric cancer drug-resistant cell line SGC7901/VCR compared with GES-1 and other gasteric cancer cell lines by Western blotting and RT-PCR.The all data reveal TWIST may play a crical role in the MDR of gastric cancer.So,in this study we want to investigat the role and molecular mechanism in multidrug resistance of gastric cancer by MTT,TAP,DNA chip and so on.More related theroy will be revealed to us to have a more profound understanding in MDR of gastric cancer.This successful operation provides evidence to validate that twist-siRNA may become a new medical technique to reverse drug resistance.

TWIST是bHLH（basic helix-loop-helix）转录因子超家族的成员，近年来研究示其参与多种肿瘤发生发展、转移等恶性生物学表现,并发现TWIST可能与肿瘤耐药有关，但与胃癌耐药的关系及机制不详。胃癌多药耐药（multidrug resistance, MDR）是胃癌化疗失败的主要原因之一。但目前仍未发现行之有效的逆转方法。我们前期研究表明TWIST参与胃癌发生发展，在胃癌耐药细胞SGC7901/VCR细胞中高表达。综上提示，TWIST可能参与胃癌多药耐药的形成。因此，本研究拟利用分子生物学和免疫学、TAP、蛋白质二维电泳及基因芯片等技术观察TWIST对胃癌多药耐药性的作用及机制，为深刻理解耐药肿瘤细胞抵抗化疗分子机制奠定一定的理论基础。从而为逆转耐药提供一种新方法。

TWIST是b-HLH(basic helix-loop-helix)转录因子超家族的成员，也是一种癌基因，参与胃癌发生发展、转移等恶性生物学表现。我们前期研究发现在胃癌耐药细胞中TWIST高表达，可能与胃癌多药耐药（multidrug resistance, MDR）有关，而胃癌多药耐药是胃癌化疗失败的主要原因之一。该课题中我们成功制备了TWIST过表达慢病毒载体和TWIST-RNAi 干扰表达慢病毒载体，用构建的重组慢病毒表达载体感染细胞、测序并用从RNA和蛋白电泳方法鉴定细胞系，多种药物敏感试验摸索了试验药物浓度，利用体外MTT法、正常免疫小鼠SRCA体内药物敏感性实验等方法，进一步证实了TWIST基因与胃癌的多药耐药表型正相关。我们通过流式检测细胞凋亡率及免疫蛋白电泳等方法检测了耐药及凋亡相关分子变化。最终发现，TWIST作为一种癌基因，不仅参与胃癌发生发展及转移，而且在胃癌多药耐药形成中起积极的作用，可能通过促进药物转运蛋白P-gp、MRP表达升高，促进细胞药物转运，也可能通过上调凋亡分子Bcl-2 及下调Bax 等凋亡分子的表达，通过抑制细胞凋亡等多种途径促进胃癌细胞多药耐药形成，而干扰TWIST表达可部分逆转这种多药耐药现象。