Expression of pY397 FAK promotes the development of non-small cell lung cancer

Focal adhesion kinase (FAK) expression has been identified as associated with cancer development and metastasis. Autophosphorylation of FAK at tyrosine (Y) 397 (pY397) performs a critical role in tumor cell signaling. However, few studies have evaluated the expression of pY397 FAK in non-small cell lung cancer (NSCLC). In the present study, pY397 FAK expression in NSCLC was investigated using immunohistochemistry. pY397 FAK staining scores were compared between various groups of specimens and the associations between clinical and pathological characteristics were investigated. A Kaplan-Meier survival curve was used to determine the association between pY397 FAK expression and the prognosis of NSCLC patients. The results of the present study revealed that pY397 FAK expression was localized to the cytoplasm of lung cells, and that pY397 FAK was overexpressed in NSCLC tissues, as well as associated metastatic tissues, when compared with the corresponding non-tumor tissues. However, no significant difference was identified between the pY397 FAK expression in primary lesions and lymph node metastases. Furthermore, pY397 FAK staining scores were not found to be associated with the tumor size, gender, degree of differentiation, histotypes, presence of lymph node metastases or survival rate of NSCLC patients. These results indicate that pY397 FAK is involved with the development of NSCLC, but is not a prognostic marker for the disease.