All-trans Retinoic Acid Promote Chemical Sensitivity Of Cisplatin On A549Cells And The Function On Expression Of Bcl-2and P53Genes

Lung cancer, with the increasing prevalence and mortality in modern society, has become top harmful to man health. The yearly increase in morbidity and mortality has drawn sufficient attention of the medical workers and even the wider society crowd. Since research on pathogenesis and emerging treatment of lung cancer has been more and more professional, people come to realize that the tumor development has been deeply association with body apoptotic mechanism obstacle. All-trans retinoic acid (all-trans retinoic acid, ATRA) that can inhibit proliferation, promote differentiation and apoptosis of tumor cells effectively, possesses unique advantage in anti-tumor. Specific mechanism of ATRA-induced apoptosis in lung cancer cells has been researching by now, however, the conclusion remains unclear. It is well acknowledged that Bcl-2and P53gene plays an irreplaceable important role in the process of apoptosis, mechanism of cell apoptosis of the two has been basically clear.Currently, chemotherapy remains the main treatment of patients with advanced lung cancer. Platinum combind with other chemotherapy drugs is still first-line chemotherapy standard in advanced non-small cell lung cancer. However, serious adverse reactions of Platinum limits its application, besides serious gastrointestinal reactions, nephrotoxicity, ototoxicity, central nervous system damage, Platinum can also cause abnormal expression of DNA damage repair gene and apoptosis inhibitor,as well as abnormal apoptosis signaling.The present experiment aims to explore the impact of ATRA combind DDP on proliferation and apoptosis of human lung adenocarcinoma cells line A549, and explore the mechanism that ATRA promotes cell apoptosis by detecting the expression of bcl-2and wild-type p53gene in treated A549cells,verify whether ATRA and cisplatin can reduce the clinical adverse reaction, promote clinical application of ATRA.Purpose:The purpose of current experiment is to explore the possible mechanism.and effect of ATRA combind cisplatin on proliferation, apoptosis of lung cancer A549cells.Methods:1. Lung cancer A549cells were routinely cultured and divided into four groups as follows:ATRA group, DDP group, ATRA+DDP group and the control group. The functions about ATRA with/or DDP in cancer cells was indirectly test with MTT method, after being treated for24hours,48hours and72hours through detecting cells light density. Evaluating the inhibition function of ATRA and DDP on lung cell cell A549.2. Apoptosis ratio of A549cells in four groups was detected by flow cytometry.3. The expression of bcl-2and wild-type p53gene of ATRA group,DDP group,ATRA+DDP group and control group was detected with Immunohistochemical mothod..Results:1. Observing in MTT, for24h,48h and72h of cell growth, compared to the negative group, the absorbance values of the ATRA group, two drugs jointed groups and cisplatin group were significantly lower, difference was statistically significant (P<0.05); in ATRA group and the combination group, difference of growth inhibition rate in24h,48h,72h was statistically significant (P<0.05); Whereas in the cisplatin group, difference of growth inhibition rate in the different time points was not statistically significant (P>0.05).2. With the results of Annexin V/PI double staining flow cytometry,we can observe that the cell apoptosis rate of ATRA, DDP and ATRA+DDP group was significantly higher than control group in24hours,48hours and72hours, respectively,which indicate that ATRA,DDP,and the two-drug combination could promote apoptosis of lung cancer cells; we can also find that the effect of proapoptotic of ATRA on apoptosis of A549cells was stronger than DDP,in addition, With time prolonged,except for control group, the apoptosis rate of the cells in each group.had all increased.3. Compared to the control group, the expression of Bcl-2gene decreased in ATRA group, DDP group and the combination group, the density and depth both are weakened, difference was statistically significant (P<0.01); Compared to the control group and DDP group, the expression of P53gene increased in ATRA group and DDP group, difference was statistically significant (P<0.01); Compared to ATRA group, The expression of P53gene in combined group increased further,difference was statistically significant (P<0.05); Results of pearson correlation reveals that the expression Bcl-2and P53gene was negatively correlated.Conclusion:1. ATRA can inhibit proliferation,promote apoptosis on lung cancer A549cells, which renders time-dependent; The inhibition rate and apoptosis rate of ATRA on A549cells can increase if combind with DDP.2. ATRA combined DDP can promote the expression of P53gene, and inhibition the expression of bcl-2gene,expression of P53and Bcl-2was negatively correlated.