Phenyhexyl isothiocyanate (PHI) has been shown to inhibit histone deacetylation in leukemia cell lines in vitro and in animal models. In this study we examined the histone acetylation status in leukemia cells from patients with acute leukemia as well as in non-leukemia cells. From January to September 2006, 19 patients with newly diagnosed acute leukemia were enrolled. 12 patients had AML, 7 had ALL. The age ranged between 2 months to 65 years old. There were 12 males and 7 females among them. 5 non- leukemia patients were also enrolled, with 1 anemia, 1 infection disease, 2 ITP, and 1 healthy volunteer. Mononuclear cells were isolated from patients’ specimen. Apoptosis of the cells and histone acetylation of H3 and H4 were characterized pre- and post- PHI treatment. The expression of acetylated H3 and H4 in acute leukemia cells was decreased, as compared to those in non-leukemia cells. Increased apoptosis was seen in the acute leukemia cells after PHI treatment of the primary culture of the leukemia cells for 3 and 7 hours. The effect of PHI on the leukemia cells from patients was time- and dose-dependent. There was a significant increase of PHI effect on leukemia cells versus non-leukemia cells (p<0.05), suggesting that PHI may have preferential activity against leukemia cells. This study presents the first evidence of PHI with preferential activity against leukemia cells over non-leukemia cells from human subjects. Clinical trial is warranted to study PHI in leukemia patients.

Author notes

Disclosure: No relevant conflicts of interest to declare.