Benzene is an environmental and industrial chemical which is widely utilized in various applications. Our previous study showed that miR-133a expression was down-regulated in chronic
benzene poisoning workers, but the mechanism of miR-133a in
benzene-induced hematotoxicity remains unclear. In this population-based study,
benzene-exposed group recruited workers whose concentration of air
benzene was 3.50±1.60mg/m(3), and control workers who were exposed to 0.06±0.01mg/m(3) air
benzene. By comparison,
Caspase-9 and
Caspase-3 was up-regulated while miR-133a expression decreased in
benzene-exposed workers. Pearson correlation analysis showed that miR-133a was reversely correlated with pro-apoptotic gene
Caspase-9 in population-based study. Moreover, multiple linear regressions indicated that miR-133a was positively associated with blood cells count. To explore the underlying mechanism of miR-133a in
benzene-induced hematotoxicity, AO/EB staining and TEM ultrastructural analysis were conducted to verify the activation of apoptosis in Human Leukemic U937 Cells induced by
benzene metabolites (1,4-Benzoquinone, 1,4-BQ), while the mechanism of miR-133a in 1,4-BQ-induced apoptosis was performed using lentivirus vectors transfection. The results demonstrated that 1,4-BQ evidently induced mitochondria-mediated apoptosis and increased pro-apoptotic genes (Caspase-9 and Caspase-3) expression in a dose-dependent manner. The mechanistic study showed 1,4-BQ decreased miR-133a expression and miR-133a over-expression attenuated 1, 4-BQ-caused upregulation of
Caspase-9,
Caspase-3 and apoptosis. In conclusion, our research suggested that
benzene induced hematotoxicity by decreasing miR-133a and caspase-dependent apoptosis which might contribute to the underlying mechanism of miR-133a in
benzene-induced hematotoxicity.