Curcumin is a potent broad spectrum inhibitor of matrix metalloproteinase gene expression in human astroglioma cells

The abnormal expression of matrix metalloproteinases (MMPs) plays an important role in the invasion of malignant gliomas into the surrounding normal brain tissue. This study showed that curcumin has broad-spectrum inhibitory activity against MMP gene expression in human astroglioma cells. RNase protection assay showed that curcumin inhibited the PMA-induced mRNA expression of MMP-1, -3, -9, and -14. Curcumin repressed the DNA binding and transcriptional activities of AP-1, which is a common upstream modulator of MMP-1, -3, and -9 gene expression. In addition, curcumin suppressed the PMA-induced MAP kinase activities, which were differentially involved in modulating the MMPs. This suggests that the inhibition of MMP transcriptions by curcumin is mediated at least in part through the AP-1 and MAP kinase pathways. Curcumin was also found to significantly repress the in vitro invasion of glioma cells. Therefore, the broad-spectrum inhibition of MMP gene expression by curcumin might provide a novel therapeutic strategy for treating gliomas.