The Impact of Si-SETDB1 on Migration and Invasion of Lung Adenocarcinoma Cells through SPG20 Methylation
Objective:To investigate the methylation levels of SETDB1 and SPG20 in lung adenocarci-noma and explore the impact of downregulating SETDB1 on SPG20 methylation,A549 cell migration,and in-vasion.Methods:Sixty cases of lung adenocarcinoma tissues and normal lung tissues were selected.qRT-PCR was used to detect mRNA relative expression levels,immunohistochemistry and western blot were used to detect protein expression levels,and gene methylation levels were assessed by bisulfite sequencing.Small in-terfering RNA(siRNA)targeting SETDB1 was constructed and transfected into cells using liposomes.qRT-PCR,Western blot,bisulfite sequencing,MTT assay,scratch healing assay,and Transwell chamber assay were performed to evaluate mRNA and protein expression,gene methylation,cell proliferation,migration,and invasion,respectively.Results:qRT-PCR results showed that SPG20 expression was downregulated(P<0.05),while SETDB1 expression was upregulated(P<0.05)in lung adenocarcinoma tissues.Western blot re-sults indicated that SETDB1 protein expression in cancer tissues was significantly higher than in normal lung tissues,whereas SPG20 protein exhibited lower expression in cancer tissues,lower than in normal lung tis-sues.In cancer tissues,the SPG20 gene methylation rate was significantly higher than in normal lung tissues,with a statistically significant difference.SPG20 methylation level was positively correlated with SETDB1 ex-pression.SETDB1 was highly expressed,while SPG20 was lowly expressed in lung adenocarcinoma cells.Conversely,in normal bronchial epithelial cells,SETDB1 was lowly expressed,and SPG20 was highly ex-pressed.RNA interference with SETDB1 significantly reduced SETDB1 mRNA and protein expression in A549 cells,decreased SPG20 gene methylation,and inhibited cell proliferation,migration,and invasion.Conclu-sion:There is a correlation between methyltransferase SETDB1 and SPG20 methylation in lung adenocarcino-ma.SETDB1 may serve as a catalytic enzyme for SPG20 methylation.