| Part 1 The study on expression of p16 protein in pancreatic carcinomaObjective To study the relationship between p16 protein and carcinogenesis of primary pancreatic carcinoma as well as its cilinical parameters.Methods The expression of p16 protein was examined by immunohistochemistry technique in 46 cases of pancreatic carcinoma and their corresponding tumor-adjacent tissues respectively,and the relationship between the results of detection and the cilinical parameter was analysed.Results Expression rate of p16 protein was found in 19 of 46(41.3%)pancreatic carcinomas, while in 44 of 46(95.7%) corresponding paracancerous tissues. The p16 protein expression rate in pancreatic carcinomas was significantly lower than that in paracancerous tissues(P<0.05). There was no relationship between the expression of p16 and clinicopathological characteristics such as tumor size, patient's sex and age (P>0.05). p16 protien expression was significantly related to the TNM staging, histological differentiation ,metastasis(P<0.05).Conclusion p16 protein plays an important role in carcinogenesis of primay pancreatic carcinoma.Absence of p16 protein indicates strong malignant potential and poor prognosis of pancreatic carcinoma. Part 2 Detection of aberrant p16 methylation in pancreatic cancer and its clinical significanceObjective To investigate aberrant methylation in the promoter area of p16 gene in pancreatic carcinoma and in the corresponding tumor-adjacent tissues, and evaluate their role in the carcinogenesis and progression of tumor and its clinical significance.Methods MSP(methylation-specific, PCR) were performed on 46 samples of pancreatic carcinoma and their corresponding tumor-adjacent tissues specimens for p16 methylation.Results Through MSP ,the methylation rate in pancreatic carcinomas was 39.1%, while 6.5% in corresponding paracancerous tissues. No gene methylation was found in 19 cases expressing p16 protein. p16 gene methylation was closely related to p16 protein expression in pancreatic carcinoma(P<0.05). There was no relationship between the aberrant methylation in the promoter area of p16 gene and clinicopathological characteristics such as tumor size, patient's sex and age (P>0.05). p16 gene methylation was significantly related to the TNM staging, histological differentiation and lymph node metastasis(P<0.05).Conclusion Our study demonstrated that methylation in the promoter of p16 gene and its protein were associated with the development of pancreatic carcinoma and could be used as a putative prognostic indicator for malignancy. |
