Expressions of Cks1, Skp2 and p27 in human gliomas and their correlations

Objective To investigate the expressions ofcyclin kinase subunit 1 (Cks1),S-phase kinase associated protein 2 (Skp2) and Cyclin-dependent kinase inhibitor p27 in human gliomas and their correlations,and study the possible role of Cks1 to glioma malignant progression.Methods Immunohistochemical staining (EnVision method) was used to measure the protein expressions of Cks 1,Skp2 and p27 in 34 human glioma samples and 10 normal brain tissue slices,collected in our hospital from June 2009 to June 2011.Relationships between these levels of these proteins were analyzed.Results The immunoreactivity scale (IRS) scores of Cksl expression in normal brain tissue,low grade gliomas and high grade gliomas were 4.90±2.38,3.20±2.98 and 2.16±2.52; Cksl expression was decreased as the tumor grade developed.Skp2 protein was negative in all 10 cases of normal brain tissues and the IRS scores of Skp2 expression in low and high grade gliomas were 1.00±1.13 and 2.26±2.23; they increased in a malignancy-dependent manner.The IRS scores of p27 expression in normal brain tissue,low grade gliomas and high grade gliomas were 7.80±0.63,5.00±2.10 and 2.21±1.47 with significant differences (P＜0.05).Significantly positive correlation was found only between expressions of Cksl and p27 (r=0.38,P＜0.05),while no significant correlations between expression of Cksl and Skp2 and expression of p27 and Skp2 were noted (r=0.08 and-0.16,P＞0.05).Conclusion Cks1,Skp2 and p27 can be used as markers to evaluate glioma histological grade; Cks1 could inhibit gliomas malignant development by promoting p27 accumulation. Key words: Glioma;  Cyclin kinase subunit 1;  S-phase kinase associated protein 2;  P27; Immunohistochemistry