Cox-2 Mediates The Promoting Effect Of HSPA12B On The Growth Of Lung Cancer

Background and ObjectiveBecause of the characteristics of fast growth,early metastasis and easy palindromia,lung cancer has high incidence and mortality in China,and the current clinical overall treatment effect 1s very poor.Depend on the previous study,the growth and metastasis of tumor mainly depend on the produce of new blood vessels,but currently the anti angiogenesis drugs are very few in clinical use,and the clinical effect is still not satisfactory.Heat shock protein A12B(heat shock protein A;12B,HSPA12B)is a new member of the heat shock protein 70(heat shock protein 70,HSP70)protein family,specifically expressed in endothelial cells,and it can promote the proliferation and migration of endothelial cells and angiogenesis in vitro,so we infer that high expression of HSPA12B may play an important role in tumor angiogenesis.Preliminary studies have confirmed that over expression of HSPA12B can significantly promote the growth of lung cancer,which suggest that HSPA12B is a new regulatory molecules which can promote eancer growth,but how HSPA12B to promote the growth of lung cancer 1s still unclear.In this study,based on the previous work,by using the HSPA12B transgenic mice Lewis lung cancer model,to study the promotion mechanism of lung cancer growth,and to find a more comprehensive understanding of lung cancer growth regulation mechanism,so as to provide some new ideas and theoretical basis for the early diagnosis and treatment of lung cancer.Methods1.The experimental animal:The transgenie mice model with high expression of human HSPA12B gene(transgenic mouse,Tg)is constructed by our laboratory and the Nanjing University model animal research laboratory,which feeding in the SPF grade animal housing of the Nanjing University model animal research laboratory,the control group choose the wild type mice(Wild type,WT)bom in the same nest.2.Lung cancer model:Using 8-10 weeks old Tg mice and litternate WT mice by tail vein injection of Lewis lung cancer(LLC),the cell number was 1.5 ×105/rat3.Tumor phenotype analysis:18 days after injection of LLC cells,Put to death the mice with excess Nembutal anesthesia,open thoracic to separate the lungs,and take photos.Then separating the lung tumor,counting and weighing.4.Cox-2 inhibition test:After injection of LLC cells,mice fed the food with Cox-2 specific inhibitor Celecoxib(Cele)(1.5 g/kg),until the end of the experiment.5.Analysis of protein expression:18 days after injection of LLC cells,collect lung tumor tissue,set normal mouse lung tissue injection of saline as control group.The analysis of protein expression according to the conventional westerm blot process.6.Apoptosis in lung cancer:18 days after injection of LLC cells,collect lung tumor tissue,to make paraffin section,and then inmunofluorescent staining of TUNEL,staining the nuclei of Hoechst33342,the degree of apoptosis show as the percent of TUNEL positive nuclei/total nuclei.7.Statistical processing:Data are expressed by the mean±standard deviation,comparison between groups use the single factor analysis of variance(ANOVA),P<0.05 represents the difference had statistical significance.Results1.The number and weight of lung tumor in HSPA12B Tg rat are significantly more than in WT rats.2.The number of lung tumor apoptosis cells in HSPA12B Tg rat are significantly less than in WT rats.3.The cell proliferation of lung tumor tissue in HSPA12BTg mouse is significantly larger than in WT rats.4.In lung tumor tissue,the expression level of Cox-2 in HSPA12B Tg rats was significantly higher than that in WT rats.5.Selective Cox-2 inhibitor Celecoxib significantly inhibited the growth of lung cancer in HSPA12B Tg rats.6.Selective Cox-2 inhibitor Celecoxib significantly increased the apoptosis of lung tumor tissue in HSPA12B Tg rats.ConclusionHSPA12B can promote the growth of lung cancer,and its mechanism is mediated by Cox-2...