Effects of HPB on cell growth and viability and acetylated patterns of proteins and histones in normal and transformed cells in culture. Normal (HFS) and transformed (LNCaP) cells were cultured with indicated concentrations of HPB for 72 h. Five micromolar SAHA is a positive control. (A) Cell growth. (B) Cell viability. Inhibition of cell growth of normal and transformed cells is concentration-dependent. Viable cells were evaluated by trypan blue staining. Data are represented as mean ± SD (P < 0.001). The P value was derived from the two-way ANOVA. (C) HPB causes accumulation of acetylated alpha-tubulin but not acetylated histone H3 in normal (HFS) and transformed (LNCaP) cells. Cells were cultured with 5 µM SAHA or 8, 16, 32, or 64 µM HPB for 24 h as indicated. SAHA, the pan-HDAC inhibitor, was the control. Cell lysates were prepared for immunoblot analysis of acetylated alpha-tubulin (Acet-Tub) and acetylated histone H3 (Acet-H3). GAPDH and total H3 are loading controls.