Studies On Expression Of P73 And Its Relation To P53 In Extraheptic Cholangiocarcinoma

Extraheptic cholangiocarcinoma(ECHC) is a kind of digestive malignant which growth slowing and metastasis later, in recent years the incidence rate of ECHC have a trend to elevation. ECHC have a higher degree of malignancy, because of difficulty to have a final diagnosis, ECHC have a low rate of operation resection and patients have a bad prognosis. But at present therapeutic efficacy still don't reach an ideal condition.Increasing genetic evidence exists that carcinogenesis must be understood in terms of accumulation of mutation in regulatory genes, including activation of oncogenes and inactivation or loss of tumor suppressor genes. Among the available candidates, the p53 gene has come to be known as a master guardian of cell and plays a role in the occurrence and development of tumor. p73, the novel homologue of the tumor suppressor gene p53, was recently discovered on chromosome lpL36 and has been shown to induce apoptosis in a p53-like manner. In some kinds of cancer, overexpression of p73 has been reported recently. But unlike p53, no significant mutation of the p73 has been found in human tumors. Its role in ECHC remains unclear The purpose of this study is to investigate the relationship between the expression of p73 and p53 and the ECHC development and malignancy, to explore the application value in prognosis on patients with ECHC, and to provide the experimental data on ECHC pathogenesis. Method: The expression of p73 and p53 in 41 cases of ECHC, 10 cases of choledochal cyst and 10 cases of normal choledochus were detected by the method of immunohistochemistry. The results obtained were analyzed with respect to their association with tumor size, pathological grade, apoptosis and, finally, prognosis. Results: By immunohistochemistry, we detected p73 protein in 17(41%) of the 41 carcinomas examined. Positive immunohistochemical staining was confined to the cell nucleus. Whereas almost all the choledochal cyst tissue, normal common bile duct were seen to be negative. We failed to observe a statistical significant relationship between p73 expression and the pathological grades and size and occurrence of apoptosis within a given tumor. The expression of p73 and p53 in ECHC and prognosis has a statistical significant relationship. Conclusion: The protein p73 and p53 is overexpressed by a subset of ECHCs, maybe involve in extraheptic cholangiocarcinoma carcinogenesis. In summary, we detected the expression of p73 and p53 in ECHC. And the two proteins anomalous overexpression was proved. We preliminarily explored the relationship between p73 and p53 and carcinogenesis and prognosis, and provided valuable data for further clinical trial of p73 in ECHC.