The Preliminary Research On The Relationship Between BMP -4 And Acute Pancreatitis,Pancreatic Cancer

Objective: To investigate expression of the bone morphogenetic protein 4(BMP-4)in mice model of acute,chronic pancreatitis,human carcinoma tissue and cells line.To discusses its roles and clinical relevance in pancreatitis and pancreatic cancer.Methods: Establishment of pancreatitis models in mice: intraperitoneal injection of Caerulein adopted internationally was used to establish the mice model of acute,chronic pancreatitis.The mice were sacrificed 24 hours and 6 weeks apart after the initial drug administration in AP and CP.The blood from the eyeball were collected Determine amylase activity and pancreatic tissues were made from wax block.Histopathological score of the pancreas,the degree of pancreatitis tissues fibering and serum amylase activity were test to evaluate establishment of the pancreatitis models.To study the expression changes of BMP-4 in the tissue of the pancreatitis: immunohistochemistry was used to observe the BMP-4 expression in the pancreatic acinar and ductal system(including PDGs)of acute or chronic pancreatitis.To confirm whether BMP-4 has biological function: cell counting kit-8(CCK8)value-added experiment and cell migration/invasion experiments on HPDE and Miapaca2 cells were carried out to observe the biological function of BMP-4 compared with the positive control group used by TGF-β.To study the expression changes of BMP-4 in the tissues and cells of pancreatic cancer: western blot were used to detect expression differences with normal pancreatic cancer cell lines,and the pancreatic cancer cases in the public database(The Cancer Genome Atlas)were investigated for BMP-4 related survival analysis and the influence of BMP-4 on prognosis.Results:We successfully established models of acute and chronic pancreatitis through intraperitoneal injection of caerulein.Amylase activity in group AP was significantly higher than that in control group(11685 + 563 vs 3562 + 365,P < 0.05),but amylase activity in group CP was significantly lower than that in control group(2560 + 374 vs 3562 + 365,P < 0.05),and we found pancreatic acinar edema,partial acinar necrosis,tissue congestion,inflammatory cell infiltration in group AP and acinus atrophy,interstitial fibrosis in group CP.The pathological scores of AP and CP were 3.33 + 0.52 and 8.50 + 0.55,and the difference between the pancreatitis groups and the control group was statistically significant(P < 0.05).The positive area of Sirius scarlet in the CP group was significantly increased(19.2 + 2.86)% vs(9.20 + 1.76)% and P < 0.05).In the control group,BMP-4 was mainly expressed in the cytoplasm of acinar cells and almost no expression of pancreatic ducts.Under the stimulation of inflammation,the positive expression area of BMP-4 in the acinar cells of group AP was slightly lower than that of the normal group,but the positive staining was found in the pancreatic duct cells,and the HIS score was significantly higher than that of the control group(P < 0.05).The expression of BMP-4 in the atrophic acinar cells of group CP was significantly lower than that in the normal group,but the expression of BMP-4 in the pancreatic duct system was significantly higher than that in the normal group,and the HIS score was significantly higher than that in the control group(P < 0.05).In the pancreatic duct system,PDGs is the stem cell nest of pancreatic ducts and an important structure for the repair of ductal epithelium.Under the stimulation of inflammation,the structure of PDGs is significantly increased and the expression of BMP-4 is highly expressed.The proliferation of HPDE and Miapaca2 cells was significantly enhanced under the BMP-4 stimulation(P < 0.05),and the proliferation of HPDE was not obvious to the metrological tolerance of BMP-4,while the proliferation of Miapaca2 showed significant metrological tolerance to BMP-4.In the BMP-4 stimulation group,the migration ability of HPDE cells and invasion ability of Miapaca2 were similar to those of TGF-beta positive control group,which was significantly higher than that of the control group(P < 0.05).The study showed that the expression of BMP-4 in pancreatic cancer cell lines was generally higher than that of normal pancreatic duct epithelial cells(HPDE and HPNE)(P < 0.05).The analysis of 177 cases collected from the public database showed that the expression of BMP-4 was abnormal in the patients with pancreatic cancer and the survival analysis found that the overall survival rate of the high expression group was significantly lower than the overall survival rate of the low expression group(P < 0.05).Conclusion: Inflammatory stimulation can induce a significant upregulation in the expression of BMP-4 in the pancreatic duct system.High expressed BMP-4 can promote cell proliferation and migration of the pancreatic duct system,and promote the repair of ductal epithelial damage.In pancreatic cancer,BMP-4 increases the proliferation and invasion of pancreatic cancer cells and contributes to the progression of the tumor.