The Role Of Notchl、Survivin、Cyclin D1in The Immortalized Human Bronchial Epithelial Cells Malignant Transformation Induced By Cigarette Smoke Condensates

Objective: To explore the molecular mechanisms of smoking-induced lung cancer process, we detected the change of Notchl、 Survivin and Cyclin Dl proteinexpression in the process of immortalized human bronchial epithelial cells(BEP2D) malignant transformation induced by cigarette smoke condensate(CSC); the change of Survivin、 Cyclin Dl、 Notch1protein after inhibiting Notch signaling; the expression of Survivin and Notchl in lung tissue of rats exposed to cigarette smoke respectively.Method:1.BEP2D cells were devided into6groups.They were BEP2D cells group(blank control),BEP2D cells treated with alcohol(solvent control)and BEP2D cells treated with CSC for10th generation,20th generation,30th generation,40th generation.2.The40th generationc(P40) cell was incubated with OUm(DMSO control)、25uM Notch pathway/γ-secretase inhibitor DBZ for48hours.3. The expressions of Notchl,Survivinand Cyclin Dl protein of BEP2D cells malignant transformation induced by CSC,the change of Survivin and Cyclin Dl protein after Notchl signaling inhibitor were detected by western blotting analysis.4.72clean healthy Wistar rats were randomly divided into2groups, one group was breeded in the normal air, another group was exposed to cigarette smoke, the two groups were executed12in1month,3months,6month respectivelyHE staining of paraffin was used to observe the transform of Lung tissue airway’structure.The protein levels of Notchl and Survivin protein were determined by immunohistochemistry respectively.Results:1. Notchl、 Survivin and Cyclin Dl did not express in the control group cells; Notchl、 Survivin and Cyclin Dl protein expression in each treatment group with CSC was significantly higher than that in the control group (all P<0.05);Notchland Cyclin Dl were weakly expressed in alcohol-exposed group cellscompared with the control group (all P<0.05), and Survivin expression did not change significantly; Notchl protein expression gradually increased in P10, P20, P30BEP2D cells and decreased in P40BEP2D cells,the expression of Survivin protein increased with the generation, Cyclin Dl was overexpression in P20, P40BEP2D cells.Compared with P10BEP2D cell, Survivin and Cyclin Dl protein expression in P20, P40BEP2D cell were significant (all P<0.05).2. Pretreatment of P40BEP2D cells with DBZ for48h,there was a significant reduction in the expression of Notchl、 Survivin and Cyclin Dl in cell treated compared with cells untreated (P<0.05).3. Exposure time extended, airway damage increased gradually; Compared with the control group in the same period,in January,March and June group,the expression of Survivin and Notchl in cigarette smoke exposed rats increased along with the extension of exposure time.The difference was statistically significant (P<0.05).Conclusion:Notchl, Survivin and Cyclin Dlare involved in human bronchial epithelial cell malignant transformation induced by CSC.Our study provides a theoretical basis for the pathogenesis of smoking-induced lung cancer,and providesnew ideas forintervention of early lung cancer and prevention of smoking in high-risk population.