Effect Of LncRNA CASC9 On Malignant Biological Behavior Of Human Lung Adenocarcinoma A549 Cells

Objective: 1.To investigate the effects of LncRNA CASC9 on the proliferation,migration,invasion and apoptosis of human lung adenocarcinoma A549 cells in vitro.2.To preliminarily study the mechanism of LncRNA CASC9 in regulating the proliferation of human lung adenocarcinoma A549 cells.Methods: 1.Quantitative real-time PCR(q RT-PCR)was used to detect the relative expression of lncRNACASC9 in human lung adenocarcinoma A549 cells compared with human bronchial epithelial cell Beas-2B cells.2.shRNA-CASC9 transfection into human lung adenocarcinoma A549 cells was designed and constructed to silence lncRNACASC9 expression,and the optimal interference group was selected as the experimental group(shRNA-CASC9),another negative control group transfected with empty plasmid group(shRNA-NC group),and an untransfected blank control group(Blank control group).3.The proliferation,migration,invasion,apoptosis and cell cycle of shRNA-CASC9 group,shRNA-NC group and Blank control group were detected by MTT assay,transwell chamber assay and flow cytometry,respectively.4.The protein expression intensity of cyclin D1,CDK4 and CDK6 in shRNA-CASC9 group,shRNA-NC group and Blank control group was detected by Western blot.Results: 1.The results of q RT-PCR experiments indicated that LncRNA CASC9 expression was significantly higher in human lung adenocarcinoma A549 cells than in human bronchial epithelial cell Beas-2B cells,(P<0.001).2.The designed shRNA-CASC9 could successfully transfect and interfere with the expression of lncRNACASC9 in A549 cells,of which shRNA-CASC9-2 had the best silencing effect,with an interference of 64%.3.The results of MTT assay indicated that the cell proliferation level in the shRNA-CASC9 group was lower than that in the shRNA-NC and Blank control groups,and there was a significant difference at 48 h,72 h,and 96 h(P<0.001).4.Transwell assay was used to detect the migration and invasion of lung adenocarcinoma cells by LncRNA CASC9,and the cell penetration modulus of the shRNA-CASC9 group was lower than that of the shRNA-NC and Blank control groups,and the difference was statistically significant(P<0.01).5.The results of flow cytometry showed that there was no significant difference in the apoptosis rate among the shRNA-CASC9,shRNA-NC,and Blank control groups(P>0.05).6.The results of flow cytometry showed that compared with the shRNA-NC Blank control group,the distribution of G0/G1 phase of the cell cycle increased and the proportion of S phase decreased significantly in the shRNA-CASC9 group,and the difference was statistically significant(P<0.001),and there was no significant difference in the distribution of G2/M phase(P>0.05).7.Western blot results indicated that the expression intensities of Cyclin D1 and CDK4 and CDK6 in the shRNA-CASC9 group were reduced to varying degrees compared with the shRNA-NC group and Blank control,which were statistically significant(P < 0.001).Conclusion: 1.LncRNA CASC9 can promote the proliferation,migration and invasion of human lung adenocarcinoma A549 cells,suggesting that LncRNA CASC9 may play a role in promoting oncogenes in lung adenocarcinoma A549 cells.2.LncRNA CASC9 may be involved in the regulation of the proliferation of lung adenocarcinoma A549 cells by regulating the CDK4/CDK6/cyclin D1 signaling pathway.