Protein kinase C inhibitor (H-7) potentiates antiproliferative effects of a polyamine biosynthesis inhibitor

In this study, a protein kinase C inhibitor, H-7, was found to potentiate the antiproliferative effects of difluoromethyl ornithine (DFMO), inhibitor of the polyamine biosynthesis, on NIH 3T3 and 3T3/SV40 cells in culture.Incubation of the cells with DFMO inhibited the cell growth, whereas the addition of polyamine spermidine to these cells restored the normal rate of cell proliferation with the fact that these cells took up the polyamine from the extracellular medium to compensate the intracellular needs