Benzene induces myelodysplasia and hematotoxicity via ferroptosis induction and downregulation of GPX4

Background

Benzene, a ubiquitous industrial chemical, is a well-established environmental toxin associated with hematological disorders such as myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML), which are characterized by impaired hematopoiesis and bone marrow failure. This study investigates the role of ferroptosis, an iron-dependent form of cell death, in benzene-induced hematotoxicity, focusing on the repression of glutathione peroxidase 4 (GPX4), a critical regulator of ferroptosis.

Materials and methods

Male C57BL/6 mice were exposed to benzene at various doses over six weeks. Ferroptosis markers, oxidative stress levels, and GPX4 expression were assessed in bone marrow and CD34⁺ hematopoietic stem cells using biochemical assays, PCR, and Western blotting. Ferroptosis was induced via CRISPR-Cas9-mediated GPX4 knockout and the ferroptosis inducer erastin. The protective effects of ferroptosis inhibitors (DFO and Fer-1) were also evaluated.

Results

Benzene exposure led to a dose-dependent reduction in red and white blood cell counts, hemoglobin levels, and bone marrow cellularity. It also elevated oxidative stress markers, disrupted iron metabolism, and suppressed GPX4 expression. GPX4 knockout and erastin treatment mimicked benzene-induced effects, causing decreased cell viability, impaired colony formation, and lipid peroxidation accumulation. Administration of ferroptosis inhibitors reversed these effects, restoring cellular function, reducing reactive oxygen species (ROS), and preventing oxidative damage. GPX4 overexpression further protected against benzene-induced ferroptosis and hematopoietic toxicity.

Conclusion

Ferroptosis plays a central role in benzene-induced hematotoxicity, mediated by oxidative stress, disruption of iron metabolism, and suppression of GPX4. Ferroptosis inhibitors show potential as therapeutic agents for mitigating benzene-induced hematological damage, offering novel therapeutic strategies for disorders induced by environmental toxins.