Promoter hypermethylation of death-associated protein kinase gene in cholangiocarcinoma

BACKGROUND: Death-associated protein kinase (DAPK) is a Ca2+/calmodulin-regulated Ser/Thr kinase which is involved in apoptosis. The aberrant methylation of its promoter region CpG islands may be one of the important mechanisms of carcinogenesis. We studied the relationship of methylation status and expression of the DAPK gene with the clinical findings in cholangiocarcinoma. METHODS: Target DNA was modified by sodium bisulfite, coverting all unmethylated, but not methylated, cytosines to uracil, and subsequently detected by methylation-specific PCR. Moreover, mRNA expression of the DAPK gene was assessed by RT-PCR. RESULTS: Aberrant methylation of the DAPK gene was detected in 11 (30.6%) of 36 tissue specimens of cholangiocarcinoma, and in 2 (5.6%) of 36 specimens of adjacent normal tissues. DAPK mRNA was not expressed in tumor and adjacent tissues with hypermethylation of the DAPK promoter. There were no statistical differences in the extent of differentiation and invasion, lymph node metastasis or pathologic type between the methylated and unmethylated tissues. CONCLUSIONS: The frequency of DAPK gene methylation in cholangiocarcinoma is high and it may offer an effective means for earlier auxiliary diagnosis of the malignancy. The DAPK gene is probably suppressed by methylation, and it could become resistant to apoptosis and immunological surveillance. The DAPK gene epigenetically affected by methylation may be associated with the carcinogenesis of cholangiocarcinoma.

Giant mucinous biliary cystadenoma:a case report

BACKGROUND: Biliary cystadenoma is a very rare cystic neoplasm of the liver. Its clinical features, diagnosis, pathologic characteristics, and optimal surgical management have not been defined clearly. In this article we describe the details of this rare disease. METHODS: A 40-year-old woman with a mass of the liver was verified by ultrasonography and LT. Ultrasonography showed a mixed echo of 18.4 cmx14.72 cmx 15.54 cm in the left lobe of the liver. CT showed a vesicula of 19.9 cmx 13.5 cm in the right epigastrium, with a low density, clear edge, uneven density, and calcified shadow. The patient received successfully a left hepatectomy. Laboratory examination showed an elevation of CA125 to 62.62 U/ml and CA199>1000 U/ml. RESULTS: After the left hepatectomy, the patient was fully recovered. Her biliary cystadenoma was characterized by specific histological findings. During operation, a large cystic lesion was seen in the left hepatic lobe; its surface was dark red with abundant blood supply. Gross examination showed that the tumor almost occupied. The whole left lobe with a small amount of normal liver tissue close to the deltoid ligament. Pathologically, additional lobulated spaces were seen in the tumor with a lot of mucusa. The interior wall was lined with bile duct tissue, indicating a benign mucinous biliary cystadenoma. CONCLUSIONS: Ultrasonography and CT are the major methods for the diagnosis of mucinous biliary cystadenoma liver. Operation is the best way of treatment.