新型姜黄素类似物WZ35通过靶向TrxR1诱导胃癌细胞凋亡以及化药增敏的作用和机制研究

The discovery of new targets and new drug candidates for the treatment of gastric cancer is of great significance. The compound WZ35 is a newly synthesized, mono-carbonyl analog of curcumin that has exhibited anti-tumor effect in gastric cancer cells. In our previous study, we found that WZ35 could induce apoptosis of gastric cancer cells through activation of ROS generation. However, the direct target of WZ35 and ROS-mediated mechanisms is still unknown. Our previous research showed that TrxR1, the critical enzyme in regulating ROS levels, was overexpressed in gastric cancer cells. Meanwhile, we found that WZ35 could bind directly to TrxR1, along with inhibition of TrxR1 activity in gastric cancer cells. Therefore, we hypothesized that WZ35 selectively kills gastric cancer cells by targeting the TrxR1 to increase ROS generation.. This project plans to identify TrxR1 is the direct target of WZ35 at the molecular level, and clarify the signaling pathways of ROS-mediated apoptosis by targeting TrxR1 protein in gastric cancer cells. Furthermore, we will verify the anti-tumor activity of WZ35 against gastric cancer and the impact of TrxR1 on the development of gastric cancer in vivo. Meanwhile, we will testify the effect on the enhancement of chemosensitivity towards first-line chemotherapeutic agents in combination with WZ35. This research project will make a valuable contribution to the evidence base about TrxR1 as a direct target of WZ35, approach to clarify the molecular mechanisms of WZ35 induced apoptosis, and provide a novel target for the treatment of gastric cancer.

胃癌新靶点和候选新药的发现有着重要的研究意义。新型姜黄素类似物WZ35是我们前期发现的具有良好抗胃癌活性的化合物，它通过激活ROS来诱导胃癌细胞凋亡，但它激活ROS的机制和直接靶点尚不清楚。TrxR1是调节ROS的重要蛋白酶，我们前期发现其在人胃癌细胞中的表达和活性升高，而WZ35能够显著的抑制TrxR1蛋白活性并能与其发生直接结合。故我们推测WZ35可能是通过靶向抑制TrxR1来上调ROS水平，发挥其抗胃癌作用。本项目拟在分子和细胞层面证明TrxR1为WZ35的直接作用靶点，深入阐明TrxR1和ROS介导WZ35抗胃癌活性的分子机制；在动物层面考察TrxR1在胃癌中的作用以及对WZ35抗胃癌活性的影响，并联合WZ35与一线化疗药物考察抑制TrxR1对化疗药物增敏的效果。本项目将确证TrxR1为WZ35的直接作用靶点，阐明WZ35抗胃癌的分子机制，提出TrxR1可以作为胃癌治疗的重要靶点。

胃癌是一种常见的恶性肿瘤，严重威胁着人们的身心健康，因此胃癌新靶点和候选新药的发现具有重要的研究和临床意义。硫氧还蛋白还原酶1（TrxR1）是体内重要的氧化还原调节蛋白。近年来研究表明TrxR1在多种肿瘤细胞中高表达，TrxR1 高表达与肿瘤的发展以及肿瘤细胞耐药密切相关，然而TrxR1在胃癌细胞中的作用尚不清楚。本研究从细胞和分子层面阐明了姜黄素类似物WZ35和EF24通过抑制TrxR1活性，上调细胞中ROS水平激活内质网应激从而诱导胃癌细胞凋亡的作用机制。动物实验表明WZ35和EF24能够明显地抑制肿瘤组织中TrxR1的活性，抑制肿瘤生长，并增敏化疗药物对肿瘤生长的抑制作用。此外，本研究发现天然产物荜茇酰胺能够明显地抑制TrxR1的活性，从而上调ROS水平，激活下游内质网应激和线粒体凋亡通路来诱导胃癌细胞凋亡。体内研究表明，荜茇酰胺能够明显地抑制肿瘤生长，且能显著地抑制肿瘤组织中TrxR1的活性。在上述基础上，本研究进一步检测了TrxR1在胃癌组织中的表达和活性。结果发现TrxR1在临床胃癌组织中的表达和活性均明显上升，表明TrxR1在胃癌的发生发展中存在着重要的作用，TrxR1是胃癌治疗的潜在作用靶点。总之，本研究表明TrxR1是姜黄素类似物WZ35和EF24以及天然产物荜茇酰胺的有效作用靶点，通过靶向作用TrxR1，WZ35、EF24和荜茇酰胺显著地上调胃癌细胞中的ROS水平，从而诱导胃癌细胞凋亡，这为WZ35、EF24和荜茇酰胺进一步应用于胃癌的临床治疗提供了理论依据。