Article
The reversion inducing gene RECK is a major regulator of MMP-expression, migration and invasion in human gliomas
Das RECK Gen reguliert MMP-Expression, Migration und Invasionsverhalten von humanen Gliomen
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Authors
Published: | May 4, 2005 |
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Outline
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Objective
The reversion inducing gene RECK (reversion inducing cysteine rich protein with Kazal motif) encodes a membrane anchored extracellular protein with protease-inhibitor-like domains. It´s expression is strongly suppressed in hepatocellular tumor cells transformed by not yet clearly identified oncogenes. Restored RECK gene expression reduces the invasive potential of hepatocellular tumor cells. We examined the expression of RECK protein and cell characteristics in human glioma cell lines and primary cultures.
Methods
RECK expression was detected by ECL Western blot and immunohistochemistry in GaMG, U251, U373 cell lines and 10 additional primary cell cultures from glioblastoma patients. All cell lines and primary cultures were analyzed by MTT-proliferation test, spheroid drop migration, amido-black adhesion assay and 3-dimensional collagen gel invasion test.
Results
NIH 3T3 cells showed a strong expression of RECK protein, low levels of MMP-9 mRNA and no 92 kDa MMP-9 protein. Traces of 72 kDa MMP-2 protein were seen. The RECK protein levels between glioma cell lines differed considerably and correlated with the expression levels of MMP-9. No differences were detected in MMP-9 and MMP-2 mRNA levels indicating that the MMP activity seen in immunohistochemistry is the result of posttranscriptional events. The results of the functional assays correlated with the respective expression of MMP-9 protein in RECK-deficient cells. A similar trend was seen for MMP-2. All tumor cell lines strongly expressed uPA, however, in no relation to respective migration or proliferation patterns.
Conclusions
RECK gene is downregulated in human glioma cell lines and primary glioma cell cultures. Consistent with other models MMP-9 expression appears to be gated by RECK expression indicated by the inverse secretion levels of MMP-9. The cell biological phenotype of RECK-deficient cells correlates with the respective MMP-9 and to a lesser extent MMP-2 expression levels providing a clue to the understanding of the interaction between RECK expression and MMP activity.