OVEREXPRESSION OF THE 18A2 MTS1 GENE AND DOWN-REGULATION OF THE TIMP-2 GENE IN INVASIVE HUMAN GLIOMA CELL-LINES IN-VITRO/

Invasion of the reconstituted extracellular matrix composite, Matrigel , by eight human glioma-derived cell lines and human fetal brain cells was assessed in vitro using 8 mu m polycarbonate filters in a modifie d Boyden migration chamber. With the exception of one low grade glioma derived cell line, all lines studied proved to be invasive while norm al fetal brain cells failed to invade. This invasive potential was ind ependent of the histological grade of the tumour from which the cell l ines originated. In addition, the expression of the metastasis-associa ted gene 18A2/mts1 as well as the tissue inhibitor of metalloproteinas es-2 (TIMP-2) was analysed in each of the glioma-derived cell lines. T he 18A2/mts1 was expressed in all the cells studied with the exception of fetal brain cells and the low grade non-invasive glioma derived IP RK-7 cell line. The 18A2/mts1 related genes coding for the S100 subfam ily of calcium binding proteins were found to be differentially and ov erexpressed in invasive cell lines. TIMP-2 was expressed only in nonin vasive cell lines. These results suggest that the 18A2/mts1 and TIMP-2 genes could play an important role in the invasive behaviour of human glioma cells in vitro.