Background/Aim: Glycogen synthase kinase 3 beta (GSK3-beta) acts either as a tumor suppressor or an oncogene in various human cancers. The present study aimed to investigate the expression and activity of p-GSK3 beta (Ser9) in oral cancer patients. Materials and Methods: We investigated the levels of p-GSK3 beta in 152 oral cancer tissues by immunohistochemistry, and explored their prognostic impact. Results: To investigate the role of p-GSK3 beta (Ser9) in OSCC progression, we first analyzed the expression levels of protein p-GSK3 beta in normal and oral cancer tissues using immunohistochemical staining. p-GSK3 beta immunostaining was detected in 32 of 152 (21.1%) oral cancer specimens. High p-GSK3 beta expression was significantly associated with T (III/IV) stage. Kaplan-Meier survival analysis revealed that high levels of p-GSK3 beta were correlated with poor survival (p=0.001) in T stage (III/IV) OSCC patients. Multivariate analyses indicated that TN stage, AJCC tumor stage, tumor differentiation status and clinical therapy, but not p-GSK3 beta levels, were independent prognostic factors.
