Expression of the phosphorylated MEK5 protein is associated with TNM staging of colorectal cancer

Abstract

Abstract Background Activation of MEK5 in many cancers is associated with carcinogenesis through aberrant cell proliferation. In this study, we determined the level of phosphorylated MEK5 (pMEK5) expression in human colorectal cancer (CRC) tissues and correlated it with clinicopathologic data. Methods pMEK5 expression was examined by immunohistochemistry in a tissue microarray (TMA) containing 335 clinicopathologic characterized CRC cases and 80 cases of nontumor colorectal tissues. pMEK5 expression of 19 cases of primary CRC lesions and paired with normal mucosa was examined by Western blotting. The relationship between pMEK5 expression in CRC and clinicopathologic parameters, and the association of pMEK5 expression with CRC survival were analyzed respectively. Results pMEK5 expression was significantly higher in CRC tissues (185 out of 335, 55.2%) than in normal tissues (6 out of 80, 7.5%; P P = 0.001), lymph node metastasis (P P P P P = 0.002) and 5-year overall survival rate (P P = 0.139; OS: P = 0.071). Conclusions pMEK5 expression is correlated with the staging of CRC and its expression might be helpful to the TNM staging system of CRC.