Matrix metalloproteinase 2 expression in invasive pituitary adenomas

doi:10.3969/j.issn.1671-2897.2003.01.003

Abstract：Objective To evaluate the relationship between the expression of matrix metalloproteinase 2(MMP-2) and the cavernous invasion of pituitary adenomas. Methods The expression of MMP-2 protein in tissue samples from 54 pituitary adenomas was examined by immunohistochemical method. In sixteen patients, the expression of MMP-2 mRNA was also examined by RT-PCR assay. Immunostaining was semiquantatively scored based on intensity (0-3) and distribution (0-3). Results Thirty-four patients were femal and 20 were male.Twelve patients showed cavernous invasion, and 42 noninvasion. The MMP-2 score of pituitary adenoma patients with cavernous invasion (4. 3 ±0. 5 ) was significantly higher than that without invasion (2. 3 ± 0. 2 ). No correlation was observed between macroadenomas and microadenomas, and also, no correlation between the functional adenomas and non-functional adenomas. Positive correlation was not found between the MMP-2 and Ki67 labeling index ( r = -0.05, P ＞ 0.05 ). MMP-2 mRNA expression was also observed significantly higher in invasive pituitary adenomas (68.3 ± 15.3 ) than those without invasion ( 21.8 ± 8.2, P ＜ 0. 05 ). Conclusion MMP-2 may be associated with the aggressiveness and invasion of pituitary adenomas and is not related with the tumor size and secretion. MMP-2 is a useful tool for assessing the invasion of pituitary adenomas.