A Study Of SMC4 Promotes Proliferation Of Non-small Cell Lung Cancer Cells By Regulating CyclinD1

Objective and background:The incidence of lung cancer has continued to increase in recent years.Its morbidity and mortality have ranked first in all types of cancer,making it a true cancer killer.The structural maintenance of chromosomes(SMC)protein is a type of chromosomal ATPase that is ubiquitous and highly conserved in the biological world.They directly or indirectly affect the structure and dynamic changes of chromosomes,and play a fundamental role in the combination of highly conserved sequences and dynamic changes in chromosomes.Studies have found that they are involved in cell mitosis,gene regulation and DNA repair,and are closely related to the occurrence of tumors.SMC4 is a member of the SMC protein family,and SMC2 constitutes the SMC2-SMC4 dimer and is involved in many aspects of the dynamic changes of the high-level chromosome structure.Comprehensive literature reports that we explore the regulatory mechanisms of SMC4 in the development of non-small cell lung cancer.This study examined the expression of SMC4 in non-small cell lung cancer tissues and cells,and examined the proliferation and cyclinD1 protein expression levels of A549/PC9 cells after over-expression of SMC4,and explored its biological role and mechanism in non-small cell lung cancer.Methods:1.qRT-PCR and Western blot method detection of SMC4 protein and SMC4 mrna expression in lung cancer and adjacent tissues2.Western blot detected the expression of smc4 and cyclind1 in different lung tissues.3.The pc DNA3.1(+)-HA-SMC4 plasmid was transfected into A549 cells and PC9 cells as the transfection group,and the A549 cells and PC9 cells transfected with the empty plasmid pcDNA3.1(+)-vector were used as the control group.4..EDU immunofluorescence detection of smc4 over expression on proliferation and proliferation of lung cancer cells.5.Western blot analysis of cyclinD1 expression in A549/PC9 cells after over-expression of SMC4.6.Statistical analysis was performed on the data using SPSS21.0 software.Measured data were expressed as mean±standard deviation.The results were analyzed by t test.P<0.05 was considered statistically significant.Results:1.The expression of SMC4 protein and SMC4 mRNA in lung cancer tissues was significantly higher than that in adjacent tissues.The difference was statistically significant.2.Compared with human normal lung epithelial cell Beas2 b and human normal embryonic lung fibroblast MRC-5 in cell experiments,the expression of SMC4 protein and cyclinD1 in lung cancer cells A549,PC9,and H1299 were highly expressed,and the difference was statistically significant.3.The result of EDF immunofluorescence showed that the proliferation ability of A549 cells and PC9 cells after over-expression of SMC4 protein was increased,and the difference was statistically significant.4.The expression of SMC4 protein was up-regulated in A549 and PC9 cells transfected with pcDNA3.1(+)-HA-SMC4 plasmid,and the expression of cyclinD1 protein was higher than that of the control group.The difference was statistically significant.Conclusion:1.SMC4 is highly expressed in lung cancer tissues and cells.2.The proliferation capacity of A549 cells and PC9 cells increased after overexpression of SMC4 protein3.CyclinD expression was up-regulated in A549 cells and PC9 cells after overexpression of SMC4 protein.