Inhibition Of Cdc6Expression Can Improve The Sensitivity Of Non-small Cell Lung Cancer Cell Line H460to Chemotherapeutic Drugs

Background:Lung cancer,which80percents are Non-small cell lung cancer,has a highincidence in China. Its morbidity and fatality rate has an upward trend. Earlydiagnosis of lung cancer is difficult, majority of them have lost the chance of surgery,so Chemotherapy is one of the main treatment for patients with advanced NSCLC.But drug resistance often makes the poor treatment of lung cancer and the survivalrate has not been significantly improved. Most chemotherapy drugs play to kill tumorcells by specifically or non specifically effecting to a particular cell cycle loci. Cdc6isone of main factors of cell cycle regulation, and its abnormal expression has a certainrelationship with tumorigenesis. So, interfering Cdc6expression whether or not canimprove the sensitivity of chemotherapy drugs for lung cancer?Methods:By western blot and Q-PCR method to detect Cdc6protein and gene expression inthe non-small cell lung cancer cell lines of H460、A549、 SPC-A-1,、NCI-H520.Finally we select H460which has the highest expression of Cdc6for the subsequentinterference and susceptibility test. First, transfecting Cdc6-siRNA into H460cell lineby transiently transfection, and detecting inhibition of Cdc6protein and geneexpression by western blot and Q-PCR method. At the same time, transfectingmiR26a and miR26b mimics into H460cell line,and detecting inhibition of Cdc6protein and gene expression by the same ways. After inhibition of Cdc6expression,we compare the chemotherapy drug sensitivity changes of gemcitabine and docetaxelto H460with Control groups by MTT.Results：Cdc6proteins and genes are high expression in non-small cell lung cancer celllines of H460、A549、NCI-H520, and there is a positive correlation between Cdc6proteins expression and genes expression. H460cell line has the highest expression ofCdc6.After H460cell line be transfected with the Cdc6-siRNA, protein and gene expression level has a significant decrease. We also found that transfected miR26aand miR26b mimics into H460cell line, Cdc6protein and gene levels have decreasedsignificantly, playing the same role of the effect of Cdc6-siRNA transfection. Afterthe decline of Cdc6expression, the significant decrease of the IC50of thegemcitabine and docetaxel, and drug sensitivity has increased significantly, Theresults have statistically significant differences(P<0.05).Conclusion：This study found that Cdc6was the trend of high expression in non-small celllung cancer cell lines. After Suppressing Cdc6expression, the sensitivity ofgemcitabine and docetaxel significantly be improved H460,one of non-small celllung cancer cell lines. Other, this study also found that high expression of Cdc6inH460cell line may has certain relationship with miR26a and miR26b lowexpression,but the specific mechanisms need to be further research...