[Effects of benzene on S+G2/M cell cycle arrest, apoptosis and oxidative DNA damage in human peripheral blood mononuclear cells].

AIM

To observe and verify the benzene-induced cell cycle arrest and apoptosis in human peripheral blood mononuclear cells (PBMCs), and explore its effects on oxidative DNA damage.

METHODS

PBMCs were isolated, cultivated for 24 h and then divided into 4 groups supplemented with alcohol solvent as a control, low, middle and high concentration benzene (0.5, 5, 50 μmol/L), respectively. Another 24 h later, we assayed the cell growth arrest by MTT, detected cell cycle and apoptosis rate by flow cytometry, the content of reactive oxygen species (ROS) by DCFH-DA assay, superoxide dismutase (SOD) activity by xanthine oxidase test, malondialdelhde (MDA) content by thiobarbituric acid test, glutathione (GSH) content by ELISA, DNA damage by single cell gel electrophoresis (SCGE) technology and micronucleus assay.

RESULTS

Compared with the control group, benzene decreased cell viability (P<0.05) and increased cell apoptosis (P<0.05) in a dose-dependent manner, along with induction of S phase and G2/M phase arrest (P<0.05). Meanwhile, benzene induced the accumulation of intracellular ROS and MDA, micronucleus rates, comet rates and comet tail length, which were found dose-dependent and statistically significant compared to the solvent control (P<0.05). The activity of SOD and the contents of GSH decreased significantly (P<0.05).

CONCLUSION

Benzene can induce cell apoptosis, S+G2/M phase accumulation and change of oxidoreduction status in PBMCs, and strengthen the effects of lipid peroxidation as well as the DNA damage.