The Expressions Of Cyclin E, Cdk2 And P27^kip1 In Invasive Pituitary Adenomas

Objective: To study on the expressions of cell cycle associated protein cyclin E, cdk2 and p27kip1 in invasive pituitary adenomas, and to investigate whether there exist correlations among the expressions of the three proteins and between the expressions of the three proteins and the invasiveness of invasive pituitary adenomas.Methods: 58 cases of fresh resected pituitary adenomas were collected, each sample was divided into three parts, one for routine detection in the department of pathology; one for Immunohistochemistry by immediately dipping into 4% paraformaldehyde, and the last one for Western blotting analysis by storing in ultra low temperature refrigerator or extracting its proteins immediately. Immunohistochemical analysis and Western blotting analysis using anti-cyclin E, anti-cdk2 and anti-p27kip1 antibodies were performed to detect the expressions of cyclin E, cdk2 and p27kip1 in pituitary adenomas.Results: The expressions of cyclin E and cdk2 in invasive pituitary adenomas were both significantly higher than that in noninvasive pituitary adenomas (both P<0.05), but the expression of p27kip1 in invasive group was significantly lower than that in noninvasive group (P<0.05). There was positive correlation between the expression of cyclin E and cdk2 in pituitary adenomas (P<0.05), and negative correlation between the expression of the former two and p27kip1 (both P<0.05); there was positive correlation between the expression of cyclin E and cdk2 and the invasiveness of pituitary adenomas (both P<0.05), and negative correlation between the expression of p27kip1 and the invasiveness of pituitary adenomas (P<0.05).Conclusions: The overexpressions of cyclin E and cdk2 and the lower expression of p27kip1 were significantly associated with the invasiveness of pituitary adenomas, cyclin E, cdk2 and p27kip1 proteins may be valuable prognostic factors for pituitary adenoma.