FIG. 6.

Treatment of CID-9 cells with histone deacetylase inhibitors induces transcription in the absence of ECM in stable BBC transfectants. (A) CID-9 cells were cultured on plastic or ECM and treated with various doses of sodium butyrate. Cell lysates were assayed for CAT activity, and the graph represents the densities relative to those of the cells on plastic with no treatment. (B and C) Representatives of at least three independent experiments where stably BBC-transfected CID-9 cells were plated on plastic in the presence of differentiation medium for 2 days before harvest. Sodium butyrate or trichostatin A was added 18 h before harvest. The autoradiograph shows a TLC separation of the CAT reaction products, utilizing 10 μg of protein from cell lysates for the assay. The graph represents density per microgram of protein per minute of CAT reaction. (The treatments described above will induce BBC activity in cells cultured on ECM by about twofold; data not shown.)