Figure 2.

Characterization of SAHA-resistant cell clones, SAHA R-4 and SAHA R-6. (A) Effect of HPCs and TSA on commitment to terminal differentiation. Cells were cultured with no addition (CTL), 5 mM HMBA, 3 μM SAHA, or TSA (12.5 ng/ml), as indicated, and commitment assays performed after 48 h of culture. After a 5-day growth period in methylcellulose, cells were scored as committed to terminal differentiation if they formed small colonies (<32 cells) and were expressing hemoglobin as determined by benzidine staining. (B) Effect of SAHA on histone acetylation in DS19 and SAHA R-4 cells. Cells were cultured in 0, 0.5, 1.0, and 2.5 μM SAHA for 2 h. Histones were isolated and analyzed on an AUT gel as indicated.