The Role Of Pim3 Protein Expression In The Mechanism Of Triptolide-induced Apoptosis In Pancreatic Cancer Cells

BackgroundPancreatic cancer is one of the most common cancers in the digestive system.Due to its prognosis is dismal in early stage,most of patients have been diagnosed too late?Because of the resistance of pancreatic cancer to the chemotherapy sensitivity,there is no significant improvement to the patients' survival.Triptolide has anti-tumor effect and will improve the sensitivity of pancreatic cancer to chemoradiotherapy.ObjectTo study the correlation between the apoptosis of bxpc-3 cells and Pim3 protein induced by triptolide in pancreatic cancer,and explore the molecular mechanism of triptolide-induce apoptosis in pancreatic cancer cells.MethodsThe proliferation inhibition effect of Bxpc-3 cells induced by Triptolide was detected by MTT assay;The apoptosis of of Bxpc-3 cells induced by Triptolide was detected by Annexin V-FITC/PI flow cytometry assay;The expression of protein such as Pim-3,EST-1 and pBad(s112)in Bxpc-3 cells was detected by Western Blot assay,the difference between the groups was analyzed with relative quantification.ResultsMTT assay showed that compared with the untreated control group,all the experimental groups showed significant differences after being treated with different concentrations(6.25 nM / L-400 nM / L)of triptolide for 24 h,48h and 72 h The inhibition of cell proliferation was(F=40.52,p<0.05;F=245.2,p<0.05;F=500.3,p<0.05),and the growth inhibition ratio was positively correlated with time.After 48 h treatment with different concentrations(12.5,25 and 50 nM / L)of triptolide,the growth inhibition ratio were positively correlated with the concentration of triptolide(38.16 ± 1.86%,12.50 nM / L,47.20 ± 0.95% nM / L),63.86 ± 1.30%(50 nM / L)(multiple comparisons between group and group,F = 1451,p <0.05).The results of inverted fluorescence microscopy showed that compared with the control group,the pancreatic cancer Bxpc-3 cells in the experimental group decreased in cell density and increased in apoptosis as the concentration of triptolide increased.Annexin V-FITC and PI staining assays showed that apoptosis of pancreatic cancer Bxpc-3 cells was observed after treatment with different concentrations(12.50 nM/L,25 nM/L,50 nM/L)of triptolide for 48 h.The proportions increased by 10.78±0.80%,30.15±1.37%,and 48.65±2.57%,respectively(F=602.6,p<0.05).Western blot assay showed that relative expression levels of Ets-1,Pim-3,and pBad(s112)proteins in the experimental groups were lower than the untreated control group in the triptolide-induced pancreatic cancer cells.With the increase of Triptolide concentration(0-50 nM / L)its expression level also decreases.Conclusions1.Triptolide has antiproliferative and apoptosis-inducing effects on human pancreatic cancer Bxpc-3 cells;2.Triptolide can inhibit the expression of Pim-3 protein in human pancreatic cancer cells Bxpc-3.3 Triptolide reduced the expression of Pim-3 protein through Ets-1,and decreased the phosphorylation of Bad protein to induce apoptosis.