CDK3 expression and its clinical significance in human nasopharyngeal carcinoma

The aim of the current study was to investigate the expression of cyclin-dependent kinase 3 (CDK3) in human nasopharyngeal carcinoma (NPC) and to evaluate its association with the clinicopathological characteristics of patients with NPC. CDK3 expression was examined in three NPC cell lines and one nasopharyngeal epithelial cell line by western blot analysis and in 94 specimens of NPC and 40 specimens of inflamed nasopharyngeal tissue by immunohistochemistry staining. CDK3 was overexpressed in the three NPC cell lines, 5-8F, CNE1 and CNE2, compared with the NP-69 nasopharyngeal epithelial cell line, and was primarily expressed in the cytoplasm. The frequency of CDK3 expression was significantly higher in NPC specimens (67%) compared with inflamed nasopharyngeal tissue specimens (12.5%; P<0.001). CDK3 expression was associated with the degree of infiltration, lymph node metastasis and tumor node metastasis clinical staging, respectively, (P<0.001) in patients with NPC. These results revealed that the expression of CDK3 is associated with the progression of NPC, and may be a potential biomarker for prediction of the prognosis of patients with NPC.