Presence of matrix metalloproteinase-2 and tissue inhibitor matrix metalloproteinase-2 gene polymorphisms and immunohistochemical expressions in intracranial meningiomas

Meningiomas are considered as bening neoplasms affecting the coverings of the central nervous system. They constitute approximately %12-20 of all intracranial tumors. Meningiomas are classified into three grades based on the WHO classification of central nervous system tumors. Although various histopathological features have been associated with recurrence or aggressive behaviour. Several studies have been undertaken concerning the proliferation potential, biological activity and the survival of the patients that have intracranial meningiomas. Matrix metalloproteinases are proteolytic enzymes that can destruct the basal membran and connective tissues. Such enzymes are important for tissue break down in the process of invasive growth. The inhibition of MMPs can be a treatment alternative for preventing brain invasion. The study group consisted of 50 operated meningioma patient s paraffinembedded tissue sections (30 µm) in University of Başkent Faculty of Medicine Department of Neurosurgery and 100 healthy person s blood samples without any history of familial malignant or benign tumors to analyze promotor section s MMP- 2 gen 735C>T, 1575G>A, 1306C>T polymorphisms and promotor section s TIMP- 2 gen 418G>A, 303C>T polymorphisms. The expresison of MMP-2 and TIMP-2 immunohistochemically analyzed in patients tissues, brain invasion and Ki-67 labelling index were examined. In our study, the statistical results showed that, Ki-67 labelling index is highly correletad with meningiomas grade but it did not show a correleation with brain invasion. The patients that have three nucleotide MMP 2 polymorphism showed a correlation with brain invasion independent of meningioma s grade and Ki-67 labelling index. Another finding was the association between all polymorphisms of MMP-2 and TIMP-2. and increase in immunostaining. It can be said that beter understanding of the polymorphisms of MMP-2 and TIMP- 2 can be benefical for genetical mechanism of meningiomas pathogenesis. Key words: brain invasion, inhibitors of matrix metalloproteinase,, matrix metalloproteinase, meningioma, polymorphism.