Relationship Between ERCC1Expression And Cisplatin Intervention In Humor Lung Adenocarcinonma Cell Line

Objective：The formation of lung cancer is more than a stage and the process ofmultiple factors, the differences of individual genetic factor and the chemotherapy drugresistance of tumor cells often lead to the treatment failure of lung cancer. Nucleotideexcision repair(NER) is a very common and mature repair way which is in DNAdamage resection, and it can repaire DNA damage which is caused by cisplatin.Theexcision repair cross-complementing gene1(ERCC1) is the key enzyme of NER way,and the expression of ERCC1is probably be related to cisplatin resistance. Theexperimental research the resistance index of cisplatin resistance A549/DDP cells lines,and the relationship between cisplatin and ERCC1, and then discusses the action ofERCC1in the process of cisplatin resistance, and can provide a certain theoretical basisof the lung cancer “individualization treatment”.Methods：Human lung adenocarcinoma A549cells lines and cisplatin resistanceA549/DDP cells lines were choosed for the subjects,1.Cisplatin resistance index ofcisplatin resistance A549/DDP cells lines were tested by the MTT methoddetection;2.The cells is intervened by different action time and different concentrationof cisplatin, and then the expression of ERCC1mRNA was measured byimmunocytohistology SABC assay respectively, the quantitative of ERCC1protein wasdetected by RT-PCR method.Results:①According to the cisplatin concentration of0ug/ml,1.5ug/ml,3ug/ml and6ug/ml and12ug/ml groups, and respectively joined in the A549cell line, then we collected the cells after24hours, the concentration of IC50of the cells is determined byMTT method, and it was found to be6.49ug/ml±1.14ug/ml, for the A549/DDP cells,after24hours according to the concentrations of cisplatin about0ug/ml,3ug/ml,12ug/ml,48ug/ml and96ug/ml, with a determined by MTT method,the IC50was33.91ug/ml±5.09ug/ml, and it also can be found that the A549/DDP cells to cisplatinresistant index is about5.22.②1. With cell immunohistochemical method,we draw that the ERCC1proteinexpression began to increase(53.15%±2.31%) when the concentration for5umol/Lcisplatin role in adenocarcinoma cells, its expression（68.52%±1.98%）is higher than theprevious group in cisplatin concentration for10umol/L, in the20umol/L under theaction of the cisplatin, ERCC1protein reached the peak, and ERCC1protein expression（61.31%±6.48%）is slightly lower in the40umol/L concentration under the action ofthe cisplatin, but they were higher than the cell without cisplatin treatment（32.77%±2.54%）, and the differences are significant（p<0.05）; When the10umol/Lcisplatin role in adenocarcinoma cells, after12hours, ERCC1gene expression（48.14%±3.55%）began to increase, and with the extension action time of cisplatin for24h（63.42%±3.97%）, and48h（72.61%±4.23%）,72h（87.21%±3.73%）, its ERCC1protein also shows obvious increase, in the72h, it reached the maximum, thedifferences are significant（p<0.05）, and ERCC1expression are higher than the cellswhich were processed with the cisplatin that its concentration is0umol/L, and thedifferences are significant（p<0.05）;2.With RT-PCR method, we saw with the changingof the cisplatin concentration for5umol/L （52.83%±0.48%）,10umol/L（56.77%±0.36%）,20umol/L（76.23%±0.26%）,the expression of ERCC1mRNA isincreased gradually, and the differences are significant（p<0.05）, however when theconcentration of the cisplatin for40umol/L, the expression of ERCC1mRNA（54.69%±0.63%）will be declined, but the groups are still greater than the expressionof ERCC1mRNA （42.88%±0.38%） without the treatment of cisplatin, and the differences are significant（p<0.05）; after the cells were processed with10umol/Lcisplatin, along with the action time12h（50.20%±4.10%）,24h（57.05%±3.51%）,48h（71.56%±2.69%）and72h（84.44%±5.56%）, the expressions of ERCC1mRNA is ina higher trending, and the differences are significant（p<0.05）, and the expression ofERCC1are higher than the cells which were processed with the cisplatin that itsconcentration is0umol/L, and the differences are significant（p<0.05）;3.Comparedwith normal lung adenocarcinoma A549cells, the expression of ERCC1protein andERCC1mRNA of lung adenocarcinoma cell of cisplatin resistance line A549/DDP, areall significantly higher, and the differences are significant（p<0.05）.Conclusion：1.Lung adenocarcinoma cell of cisplatin resistance line A549/DDP hasthe resistance of DDP;2. In a certain range，with the increasing of cisplatin action timeand cisplatin concentration, the expression of ERCC1mRNA and ERCC1protein isincreased of lung cancer cells. So ERCC1may be involved in the happening of cisplatinresistance.