Mice inhaled 300 ppm benzene vapor for 8 weeks and TSA or MCP30 was intraperitoneally injected at a dose of 1 mg/kg. After all mice were killed, bone marrow mononuclear cells were separated and measured the expression of Topo IIα including mRNA (A), protein (B), and activity (C) using RT-PCR, western blot, and Topo II activity assay kit, respectively. GAPDH was used as a reference gene in RT-PCR analysis, and TBP was used as loading control in western blot analysis. Images representing 8 mice per group were shown in left column and statistical data were shown in right column. *P < 0.05, compared to the control group; #P < 0.05, compared to the benzene alone-treated group.