INHIBITION OF HUMAN-MALIGNANT GLIOMA CELL MOTILITY AND INVASION IN-VITRO BY HYPERICIN, A POTENT PROTEIN-KINASE-C INHIBITOR

The effect of hypericin, an antiviral drug and a potent protein kinase C (PKC) inhibitor, on glioma cell invasion was investigated in vitro. Treatment of the established human glioblastoma cell line, T98G, with 1 mu M hypericin for 24 h resulted in a significant inhibition of the cell invasion through an artificial basement membrane, but not cell a ttachment or proliferation. Furthermore, tamoxifen and staurosporine, both PKC inhibitors, also inhibited T98G cell invasion, suggesting tha t PKC may be the cellular target for hypericin-inhibited glioma cell m igration. Similarly, hypericin decreased cell motility significantly i n established Lines, T98G and U87-MG, and also in a low-passage human malignant glioma cell line. Thus, hypericin may prove useful for study ing mechanisms of glioma invasion, and may represent a new agent in ma lignant glioma therapy. (C) 1997 Elsevier Science ireland Ltd.