Expression Of ERK1/2 And DNMT1 In Lung Adenocarcinoma Cells After ERK1 Knockdown Mediated By Interference And Its Clinical Significance

Objective: Non-small cell lung cancer(NSCLC)is the result of the imbalance of multi-gene expression regulation,which is initiated by molecular variation caused by oncogene activation and tumor suppressor gene inactivation,and abnormal methylation of tumor suppressor genes is an important factor in its development.DNA methyltransferase(DNMTs)is involved in tumorigenesis and development,which is achieved by regulating tumor intracellular methylation,in which DNMT1 is the key enzyme that catalyzes gene methylation.Mitogen-activated protein extracellular signal-regulated kinase pathway regulates a variety of biological behaviors.The extracellular signal-regulated kinase1/2(ERK1/2)pathway promotes or inhibits cell proliferation according to cell types and genes activated in different cell environments.ERK1 and ERK2 have the same type-specific function,which leads to differences in signal transduction.On the basis of domestic and foreign studies,the RNA interference lentiviral vector of extracellular signal regulated kinase 1 gene(LV-ERK1-RNAi)was transfected into non-small cell lung cancer cells to silence ERK1 gene.The expression of ERK1/2,DNMT1 m RNA,ERK1,phosphorylated ERK1(p-ERK1)and DNMT1 protein were observed to explore its regulatory mechanism.It provides new clues for the study of the upstream regulatory pathway of DNA methylation in lung cancer,which is beneficial to the development of therapeutic drugs and the exploration of cancer prevention and treatment strategies.Methods: NCI-H1299 cells were cultured in vitro,the cells were divided into 3 groups,KD group and NC group cells were transfected with LV-ERK1-RNAi,the negative control virus,CON group received no treatment.72 h after transfection,Cells fluorescence rate were observed using fluorescence microscopy,The expression of ERK1/2 and DNMT1 m RNA was detected by Real-time Quantitative PCR Detecting System(q PCR),Western blot detected ERK1,p-ERK1,DNMT1 protein of cells.Results: There was no expression of GFP in blank control group,and the transfection efficiency of negative control virus group and LV-ERK1-RNAi group was over 80%.Compared with NC group and CON group,the expression abundance of ERK1 m RNA in KD group decreased significantly,the difference was statistically significant(P <0.05);the expression of ERK2 m RNA slightly increased(P >0.05);the abundance of DNMT1 m RNA expression decreased significantly,and the difference was statistically significant(P <0.05);The protein expression levels of ERK1,p-ERK1 and DNMT1 in KD group were significantly lower than those in NC group and CON group(P < 0.05).Conclusion: After LV-ERK1-RNAi transfection,the expressions of ERK1,DNMT1 m RNA and ERK1,p-ERK1,DNMT protein in NCI-H1299 cells were reduced,and the expression of ERK2 was normal,indicating that LV-ERK1-RNAi specifically knocked down ERK1 and inhibited the expression of DNMT1.Through the inactivation of carcinogenic kinases and interruption of signaling pathways,it provides research data for the apparent treatment of lung cancer and target selection.