Clinical significance of focal adhesion kinase in resectable pancreatic cancer

Focal adhesion kinase (FAK) is a non-receptor, cytoplasmic protein tyrosine kinase that is involved in the regulation of cellular signaling, migration, apoptosis, and cell cycle progression. Previous reports have shown that FAK is expressed in various kinds of cancer tissues and cancer cell lines; however, no information is available about human pancreatic carcinoma specimens. Tissue such specimens were obtained from 50 patients who underwent pancreatic resection for pancreatic invasive ductal carcinoma at our institute from 1996 to 2002. Immunohistochemical analysis of FAK was performed in the resected specimens. Focal adhesion kinase expression in seven human pancreatic cancer cell lines was analyzed by reverse transcription polymerase chain reaction (PCR) analysis and Western blot analysis. Focal adhesion kinase expression was detected in 24 of 50 cases (48%). There was a statistically significant correlation between FAK expression and tumor size (P = 0.004), although FAK expression did not significantly correlate with other factors such as tumor histological grade, lymph node metastasis, distant metastasis, histological stage, and overall survival. Reverse transcription PCR analysis and Western blot analysis showed that FAK was expressed in all seven pancreatic cancer cell lines. Focal adhesion kinase expression was not directly related to clinicopathological factors except tumor size in pancreatic carcinoma. Focal adhesion kinase expression may not be a prognostic marker for pancreatic cancer patients.