Expression of Etk/Bmx Tyrosine Kinase in Intrahepatic Cholangiocarcinoma

Background Epithelial and endothelial tyrosine kinase (Etk), also known as bone marrow X kinase (Bmx) plays an important role in the growth, differentiation, apoptosis, proliferation, and tumorigenicity of epithelial cells. The purpose of this study was to investigate the expression of Etk/Bmx in intrahepatic cholangiocarcinoma (ICC) and correlated the expression with clinicopathological parameters. Methods Fifty-seven cases of ICC were immunostained for Etk/Bmx, HCV NS5, PCNA, bcl-2, and NF-κB p65. Results Etk/Bmx expression was present in 19 (33.3%) of 57 ICC specimens and correlated with cell differentiation and survival rate but not closely with tumor size and lymph node metastasis. There was a significant difference of expression of either PCNA-LI or Bcl-2 between Etk/Bmx-positive and -negative cases (P < 0.05). However, no statistically significant association was found between Etk/Bmx expression and presence of HCV-NS5 or NF-κB p65. Conclusions Our results indicate that Etk/Bmx may be involved in the development of ICC and be a predictor of poor prognosis for ICC. HCV infection and NF-κB appears unrelated to Etk/Bmx expression. J. Surg. Oncol. 2008;97:428–432. © 2008 Wiley-Liss, Inc.