THE PLEIOTROPIC EFFECT OF TPA ON IN-VITRO INVASION MIGRATION OF GLIOMA AND MELANOMA CELL-LINES/

The invasion/migration of two cell lines, melanoma (MEW) and glioma (B T5C), and their counterparts treated for prolonged time with TPA were studied. On Western blots both cell lines expressed alpha, beta I prot ein kinase C isoforms, whereas beta II and gamma were not detected. Th e down-regulation of alpha and beta I PKC was observed in glioma cells after long treatment with TPA, whereas the same treatment of melanoma cells did not lead to PKC downregulation. The down-regulation of PKC was accompanied by stimulation of cell migration/invasion through Tran swell chambers coated with collagen IV or fibronectin. In the case of melanoma cells treated with TPA, whose PKC was not down-regulated, the inhibition of migration/invasion was observed. The invasive propertie s of studied cells did not correlate with any conventional PKC isoform expression.