Depsipeptide treatment induced accumulation of histone acetylation and altered the expression of cyclin A, p21, Bcl-2, and Bcl-XL in HTLV-I–infected cell lines. (A) Accumulation of histone H3 acetylation after depsipetide treatment. MT-2 and Hut102 cells were treated with 5 ng/mL of depsipeptide for 24 hours and 48 hours. Total cell lysate (50 μg/lane) was separated on sodium dodecyl sulfate-polyacrylamide gels and transferred to the membrane. Acetyl-histone H3 or histone H3 levels were detected by Western blot with specific antibodies. (B) Effect of depsipeptide on the expression of cyclin A, cyclin D, p21, Bcl-2, Bcl-XL, and viral protein Tax. Cell lines were treated with 5 ng/mL of depsipeptide for 24 hours and 48 hours, and then total cellular protein was extracted and Western blot analysis was performed.