KRAS G12V突变上调PD-L1对肺癌A549细胞转移活性的影响

Effect of KRAS G12V mutation on metastatic activity of A549 cells by upregulation of PD-L1

[目的]通过探究KRAS G12V突变对非小细胞肺癌(small cell lung cancer,SCLC)生物学过程的影响以及相关机制,以期为NSCLC治疗提供新思路。[方法]通过MTT实验分析A549细胞的生长活性;通过划痕实验和Transwell实验分析A549细胞的迁移和增殖能力;通过流式细胞术分析A549细胞的凋亡情况;通过蛋白免疫印迹分析A549细胞PD-L1的表达;通过免疫组化实验分析人肺癌组织中PD-L1的表达。[结果]与KRAS野生型的A549细胞比较,KRAS G12V突变型的A549细胞具有更强的生长(P<0.05)、迁移(P<0.05)和侵袭能力(P<0.05),KRAS G12V突变型的A549细胞凋亡率更低(P<0.05)。此外,与KRAS野生型细胞系、肿瘤组织相比,PD-L1水平在KRAS G12V突变型细胞系以及肿瘤组织中表达急剧增加。[结论]KRAS G12V突变的A549细胞具有更强的转移能力,可能与肿瘤细胞中PD-L1的激活密切相关。

[Objective]To investigate the effect of KRAS G12V mutation on the biological process of non-small cell lung cancer(SCLC)and the related mechanism,in order to provide new ideas for the treatment of NSCLC.[Method]The growth activity of A549 cells was analyzed by MTT assay;the migration and proliferation ability of A549 cells were analyzed by scratch assay and Transwell assay;the apoptosis of A549 cells was analyzed by flow cytometry;the expression of PD-L1 in A549 cells was analyzed by protein immunoblotting;the expression of PD-L1 in human lung cancer tissues was analyzed by immunohistochemistry assay.[Result]Compared with KRAS wild-type A549 cells,KRAS G12V mutant A549 cells had stronger growth(P<0.05),migration(P<0.05)and invasive ability(P<0.05),in addition to lower apoptosis rate in KRAS G12V mutant A549 cells(P<0.05).Furthermore,PD-L1 levels were dramatically increased in KRAS G12V mutant cell lines as well as in tumor tissues compared to KRAS wild-type cell lines and tumor tissues.[Conclusion]KRAS G12V mutant A549 cells have a stronger metastatic capacity,and this consequence may be closely related to PD-L1 activation in tumor cells.