Investigation of Ifosfamide Toxicity Induces Common Upstream Regulator in Liver and Kidney

Ifosfamide is an alkylating agent, a synthetic analogue of cyclophosphamide, used to treat various solid cancers. In this study, the toxicity of ifosfamide was evaluated using single-and multiple-dose intraperitoneal administration in rats under Good Laboratory Practice guidelines, and an additional microarray experiment was followed to support toxicological findings. A single dose of ifosfamide (50 mg/kg) did not induce any pathological changes. Meanwhile, severe renal toxicity was observed in the 7 and 28 days consecutively administered groups, with significant increases in blood urea nitrogen and creatinine levels. In the tox-list analysis, cholesterol synthesis-related genes were mostly affected in the liver and renal failure-related genes were affected in the kidney after ifosfamide administration. Moreover, interferon regulatory factor 7 was selected as the main upstream regulator that changed in both the liver and kidney, and was found to interact with other target genes, such as ubiquitin specific peptidase 18, radical S-adenosyl methionine domain containing 2, and interferon-stimulated gene 15, which was further confirmed by real-time RT-PCR analysis. In conclusion, we confirmed kidney-biased ifosfamide organ toxicity and identified identically altered genes in both the liver and kidney. Further comprehensive toxicogenomic studies are required to reveal the exact relationship between ifosfamide-induced genes and organ toxicity.

The role of ferroptosis in organ toxicity

Ferroptosis, an iron-dependent form of programmed cell death, is characterized by iron overload, increased reactive oxygen species (ROS) generation, and depletion of glutathione (GSH) and lipid peroxidation. Lipophilic antioxidants and iron chelators can prevent ferroptosis. GSH-dependent glutathione peroxidase 4 (GPX4) prevents lipid ROS accumulation. Ferroptosis is thought to be initiated through GPX4 inactivation. Moreover, mitochondrial iron overload derived from the degradation of ferritin is involved in increasing ROS generation. Ferroptosis has been suggested to explain the mechanism of action of organ toxicity induced by several drugs and chemicals. Inhibition of ferroptosis may provide novel therapeutic opportunities for treatment and even prevention of such organ toxicities.