基质硬度通过PGK1介导的糖酵解及Arp2/3依赖的肌动蛋白聚合调控结直肠癌侵袭和转移的分子机制

More and more attention has been paid to the study on the regulation of matrix stiffness on tumor invasion and metastasis. In the previous study, we found that higher matrix stiffnes promoted the invasion of colorectal carcinoma (CRC) cells. Based on the analysis of gene chip and pre-experimental results, we put forward that the mechanical sensing signaling integrinβ1/FAK, glycolysis induced by PGK1 and Arp2/3 dependent actin polymerization might be involved in the regulation of matrix stiffness on tumor progression. This study will explore at the levels of cell lines, nude mice and tissue samples, (1) matrix stiffness regulates integrinβ1/FAK/AKT/GSK-3βsignaling to promote the nuclear translocation of β-catenin and up-regulation of c-Myc; (2) c-Myc transcriptionally regulates the glycolysis induced by PGK1 in CRC cells; (3) matrix stiffness regulates the interactions between FAK and Arp2/3 to enhance Arp2/3 dependent actin polymerization; (4) high matrix stiffness promotes CRC invasion and metastasis through glycolysis induced by PGK1 and Arp2/3 dependent actin polymerization. This study aims to provide new clues for illustrating the molecular mechanism of tumor metastasis, and provided novel targets and therapy strategy against tumor metastasis in terms of mechanics.

基质硬度在肿瘤侵袭转移中的调控研究受到越来越多的重视。前期工作中，我们发现硬纤维蛋白凝胶能促进结直肠癌细胞侵袭能力，根据基因芯片及预实验结果，我们提出机械传导信号Integrinβ1/FAK、PGK1介导的糖酵解及Arp2/3依赖的肌动蛋白聚合参与基质硬度对结直肠癌演进的调控过程。本研究拟从细胞、动物水平及组织标本上探讨（1）基质硬度调控Integrinβ1/FAK/AKT/GSK-3β通路，促进癌细胞β-catenin入核及c-Myc表达上调；（2）c-Myc转录调控癌细胞中PGK1介导的糖酵解过程；（3）基质硬度调控FAK与Arp2/3相互作用，增强Arp2/3依赖的肌动蛋白聚合能力；（4）基质硬度增加通过PGK1介导的糖酵解及Arp2/3依赖的肌动蛋白聚合促进结直肠癌侵袭和转移。旨在为肿瘤转移机制研究提供新的观点，从微环境机械力学角度为抗肿瘤转移提供有效的靶点及治疗策略。

Integrinβ1、β-catenin、c-Myc及PGK1是我们前期利用基因芯片筛选的在软硬胶中的差异表达基因。我们通过蛋白印迹及免疫荧光证实Integrinβ1、c-Myc和PGK1在硬胶中高表达，β-catenin出现核转位；通过荧光素酶报告系统和ChIP实验证实c-Myc是PGK1的上游转录因子；通过免疫印迹实验及免疫荧光实验证实PGK1可通过FMNL2调控结直肠癌细胞的EMT及侵袭；通过免疫组化及免疫印迹证实PGK1在结直肠癌组织中高表达。本项目揭示了一个PGK1新的调控机制，即PGK1的转录在c-Myc的调控下，通过FMNL2促进结直肠癌侵袭。这一新机制不仅为结直肠癌的演进提供理论基础，更为PGK1作为潜在的结直肠癌侵袭的分子标志物提供科学依据，以及可能为结直肠癌侵袭转移的临床干预提供新的治疗靶点。