Heat shock suppresses membrane type 1-matrix metalloproteinase production and progelatinase A activation in human fibrosarcoma HT-1080 cells and thereby inhibits cellular invasion.

Expression of membrane type-1 matrix metalloproteinase (MT1-MMP) is closely correlated with tumor invasiveness. We investigated the effect of hyperthermia on the production of MT1-MMP in human fibrosarcoma HT-1080 cells. Heat shock at 42 degrees C suppressed the production and gene expression of MT1-MMP in HT-1080 cells. Heat shock-induced suppression of MT1-MMP production resulted in the inhibition of progelatinase A (proMMP-2) activation and the increased release of tissue inhibitor of metalloproteinases 2 from cell surface. In addition, in vitro tumor invasion assay in a Matrigel model indicated that heat shock inhibited the invasive activity of HT-1080 cells. These results suggest that heat shock preferentially suppresses the production of MT1-MMP and thereby inhibits proMMP-2 activation, events which subsequently inhibit tumor invasion. Therefore, heat shock shows an anti-invasive effect along with the known mechanism of inhibiting tumor growth.