Invasion of v-FosFBR-transformed cells is dependent upon histone deacetylase activity and suppression of histone deacetylase regulated genes

Transformation of fibroblasts with the v-fos oncogene produces a highly invasive phenotype that is mediated by changes in gene expression. Inhibition of histone deacetylase (HDAC) activity with trichostatin A (TSA) or valproic acid (VPA) at concentrations that do not affect morphology, motility, chemotaxis or proliferation, strongly inhibits invasion and results in the re-expression of a significant proportion of those genes that are downregulated in the v-Fos-transformed cells. Independent expression of three of these re-expressed genes, (Ring1 and YY1 binding protein (RYBP); protocadherin gamma subfamily C, 3 (PCDHGC3); and signal transducer and activator of transcription 6 (STAT6)) in Fos-transformed cells, has no effect on morphology, motility, chemotaxis or proliferation, but strongly inhibits invasion. Therefore, we conclude that the ability of v-Fos-transformed cells to invade is dependent upon repression of gene expression through either direct or indirect HDAC activity.