Expression of Skp2 and p27kip1 proteins in hypopharyngeal squamous cell carcinoma and its clinical significance.

The aim of the present study was to determine the effect of S-phase kinase-associated protein 2 (Skp2) and cyclin-dependent kinase inhibitor p27kinase-interacting protein 1 (p27kip1) protein expression on the occurrence and development of hypopharyngeal squamous cell carcinoma. The protein expression levels of Skp2 and p27kip1 were detected in 42 hypopharyngeal squamous cell carcinoma and 15 normal hypopharyngeal mucous membrane specimens using the an immunohistochemical PV-9000 two-step method. The expression levels of Skp2 protein were significantly different in hypopharyngeal squamous cell carcinomas and normal hypopharyngeal mucous membranes (61.90 vs. 26.67%; P<0.05). By contrast, the protein expression levels of Skp2 were significantly positively correlated with tumor T stage (rs=0.329, P<0.05) and cervical lymph node metastasis (rs=0.402, P<0.05). Furthermore, the expression levels of p27kip1 protein were significantly different in hypopharyngeal squamous cell carcinomas and normal hypopharyngeal mucous membranes (11.9 vs. 53.33%; P<0.05), while p27kip1 protein expression was significantly negatively correlated with tumor T-stage (rs=-0.351, P<0.05) and cervical lymph node metastasis (rs=-0.371, P<0.05). Notably, a significant negative correlation was observed between the expression levels of Skp2 and p27kip1 proteins in hypopharyngeal squamous cell carcinoma (P<0.05). In addition, abnormal expression levels of Skp2 and p27kip1 proteins were observed in hypopharyngeal squamous cell carcinoma tissues. Thus, Skp2 and p27kip1 proteins may be involved in the development of hypopharyngeal squamous cell carcinoma. The current study proposed that combined detection of Skp2 and p27kip1 may be useful for assessing the characteristics and prognosis of hypopharyngeal squamous cell carcinoma.