Effect Of Rh-Endostatin On The Expression Of ERCC1 In Human Lung Adenocarcinoma A549 Cells

Lung cancer is one of the malignant tumor with gradually increased incidence in recent years,all sorts of drug-resistant phenomenon greatly limits its clinical curative effect.Therefore,study on the genes involved in resistance and related mechanism will greatly help the treatment of lung cancer.Cisplatin(DDP) is one of the most frequent used chemotherapy drugs for lung cancer,which can block DNA replication in cancer cells by inducing DNA damage.The DNA repair system can repair DNA damage caused by drugs and lead to resistance of cancer cells to treatment.Current research shows that expression of ERCC1 is related to cisplatin resistance.Rh-Endostatin,commodity called Endostar,is China's first self-developed production of anti-angiogenesis drugs.It can improve the efficacy of treatment in combination with chemotherapy drugs.It has fewer side effects and is relatively safe.In this study,human lung cancer A549 cells were treated by DDP,and/or Endostar,then expression of ERCC1 mRNA was analysed.Objective: To investigate the effect of Endostar and/or DDP on the expression of ERCC1 gene and to provide help to the secondary treatment of lung cancer.Methods: Human lung adenocarcinoma A549 cells were treated by DDP and rh-Endostatin.MTT method was used for detecting growth inhibition of A549 cells by Rh-Endostatin,DDP and combination of both drugs to determine the applied concentration.A549 cells were divided into 4 dosing group,and a control group:(1)one shot of DDP(0.34μg/ml);(2)three-time administration of DDP(0.11μg/ml, everyday); (3)one shot of DDP (0.34μg/ml) and Rh-Endostatin (300μg/ml); (4)three-time administration of DDP (0.11μg/ml,everyday)and Rh-Endostatin(300μg/ml) at the same time;(5)control group.Real time PCR was used to compare mRNA expression of ERCC1 genes in each group.Results:1.By MTT method,Rh-Endostatin had no cytotoxic effect on A549 cells at the concentration of 300μg/ml. IC₃₀ of DDP to A549 cells was 0.34μg/ml,and IC₃₀ of DDP in combination with Rh-Endostatin to A549 cells was 0.13μg/ml.2.By real time PCR,mRNA relative expression of ERCC1 genes in each group were as follows:①1.00;②0.88;③2.00;④1.90;⑤0.77.The resulting:(1)Expression in all treatment groups was higher than that in control group.(2)Expression in combination treatment groups was higher than those in single-drug treatment group.Conclusions:1.Cytotoxic effect of DDP to lung adenocarcinoma A549 cells is enhanced by Rh-Endostatin.2.Expression of ERCC1 mRNA in A549 cells is enhanced in combination treatment by DDP and Rh-Endostatin.