具核梭杆菌通过上调c-Jun表达促进结直肠癌细胞系caco-2的DNA复制

摘要

目的 研究具核梭杆菌(Fusobacterium nucleatum,Fn)促进结直肠癌(colorectal cancer,CRC)细胞系caco-2 DNA复制,并初步探讨其机制.方法 Fn感染caco-2细胞后,通过EdU检测caco-2细胞DNA复制情况,采用RT-PCR及Western blotting检测c-Jun基因转录和蛋白表达,Western blotting检测细胞增殖相关基因CCND1的表达,利用siRNA敲低c-Jun表达,Western blotting技术检测感染Fn后caco-2细胞CCND1蛋白表达及EdU检测caco-2 DNA复制情况.结果 Fn感染caco-2细胞6 h后,caco-2细胞DNA复制显著增加,c-Jun和Cyclin D1表达量增加,Fn感染并敲低c-Jun后,caco-2细胞DNA复制减少,Cyclin D1蛋白表达量也显著降低.结论 Fn可通过上调c-Jun的表达促进CRC细胞系caco-2的DNA复制.%Objective To investigate the DNA-replication induced by Fusobacterium nucleatum (Fn) in human colorectal cancer (CRC) cell line caco-2 cells, in order to make a preliminary discussion on the mechanism.Methods The DNA-replication was detected by EdU (5-Ethynyl-2′-deoxyuridine) and the expression of c-Jun was detected by RT-PCR and Western blotting after caco-2 cells infected with Fn.The expression of CCND1 was detected by Western blotting after caco-2 cells infected with Fn.c-Jun was knocked down by specific siRNA transfection cells, while these cells were infected by Fn, the DNA-replication was detected by EdU as wells as the expression of CCND1 was detected by Western blotting.Results After 6 hours infected by Fn, DNA-replication detected by EdU was significantly increased in caco-2 cells.The levels of c-Jun and Cyclin D1 were significantly increased in caco-2 cells during Fn infection.Furthermore, When Fn was infected and c-Jun was knocked down, the DNA-replication was decreased in caco-2 cells and the expression of Cyclin D1 protein was significantly decreased.Conclusion Fn can stimulate the DNA-replikation of caco-2 cells via increasing the expression of c-Jun.