| Autor: |
Groft, L L, Muzik, H, Rewcastle, N B, Johnston, R N, Knäuper, V, Lafleur, M A, Forsyth, P A, Edwards, D R |
| Předmět: |
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| Zdroj: |
British Journal of Cancer; 7/1/2001, Vol. 85 Issue 1, p55, 9p |
| Abstrakt: |
Studies have suggested that an imbalance of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) may contribute to the malignant phenotype of gliomas. In this study, we have undertaken a detailed analysis of expression of the TIMP family in normal human brain and malignant gliomas at both the mRNA and protein level. Reverse transcription-PCR (RT-PCR) analyses of total RNA from surgical tumour specimens revealed unique expression patterns for the 4 members of the TIMP family, with TIMP-1 and -4 showing positive and negative correlations, respectively, with glioma malignancy. By RT-PCR, TIMP-2 and TIMP-3 expression did not change with tumour grade. In situ hybridization localized TIMP-1 to glial tumour cells and also to the surrounding tumour vasculature. TIMP-4 transcripts were predominantly localized to tumour cells, though minor expression was found in vessels. Recombinant TIMP-4 reduced invasion of U251 glioma cells through Matrigel, and U87 clones overexpressing TIMP-4 showed reduced invasive capacity in vitro. TIMP-4, but not TIMP-1, blocked Membrane Type-1-MMP-mediated progelatinase-A (MMP-2) activation in human umbilical vein endothelial cells. The differential expression and localization of individual TIMPs may contribute to the pathophysiology of human malignant gliomas, particularly with regard to tumour vascularization. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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