【摘要】 目的探讨miR-34a和CTHRC1在结直肠癌中的生物学功能,miR-34a参与结直肠癌发生的可能机制。方法采用qRT-PCR检测miR-34a在结肠癌患者及五株不同结肠癌细胞中的表达;采用双荧光素酶法分析miR-34a与CTHRC1之间的靶向关系;通过将miR-34a过表达或敲除质粒转染入HT-29细胞,采用流式细胞术、MTT法和Transwell法分别观察细胞的凋亡、细胞周期、增殖、侵袭及迁移情况。结果 qRT-PCR结果显示miR-34a在结肠癌组织中表达下调,且在结直肠癌细胞株HT-29中的表达最低。双荧光素酶测定法也确定miR-34a可直接靶向调控CTHRC1。此外,上调miR-34a的表达后可诱导细胞周期停滞、促进细胞凋亡、抑制细胞增殖,但下调miR-34a的表达则可抑制细胞凋亡并促进细胞周期和细胞增殖。最后,Transwell实验也发现过表达miR-34a,可显著性地降低HT-29细胞的侵袭和迁移,但抑制miR-34a则可显著性地增加HT-29细胞的侵袭和迁移。结论 miR-34a可通过调控CTHRC1的表达而在体外阻止结直肠癌的进展和转移,因此,miR-34a可能为后续开发结直肠癌的新型抗癌分子提供了新的方向。更多还原

【Abstract】 Objective The purpose of this study was to explore the biological functions of miR-34 a and CTHRC1 in colorectal cancer. Methods qRT-PCR was applied to examine the miR-34 a expression in colorectal cancer patients and five colorectal cancer cell strains. Dual luciferase assay was used to confirm the target interaction between miR-34 a and CTHRC1. Flow cytometry, MTT assay and Transwell assays were utilized to measure apoptosis, cell cycle, cell proliferation, cell invasion and migration, respectively, in HT-29 cells by transfecting with miR-34 a over-expression or knockdown plasmids. Results Our results showed that the miR-34 a expression was decreased in colorectal cancer tissues and it presented the lowest level in HT-29 cells. Furthermore, miR-34 a directly targeted CTHRC1 as determined by dual-luciferase assay. Additionally, up-regulated miR-34 a expression accelerated cell apoptosis, inhibited cell proliferation and induced cell cycle arrest, while down-regulated miR-34 a expression suppressed apoptosis and promoted cell cycle and cell proliferation. Finally, it was also found that miR-34 a remarkably decreased the number of invasive and migratory HT-29 cells, but miR-34 a inhibitor markedly increased number of invasive and migratory HT-29 cells. Conclusion miR-34 a hinders HT-29 cell growth and metastasis via targeting CTHRC1, thereby these results indicate that miR-34 a might provide new direction for the therapy of colorectal cancer in the future.更多还原