The anthelmintic drug fenben is currently used to treat parasites in cattle. It’s also been repurposed to fight cancer and is being studied in humans. But turning animal anthelmintic medications into effective drugs is a long journey, as one McMaster University professor explains in this article for the AFP.
In recent years, several studies have shown that the benzimidazole anthelmintic agents have antitumor activity. Dogra et al reported that when human lung adenocarcinoma cells were transplanted into female athymic nu/nu mice, the administration of 1 mg/mouse of fenbendazole for 12 days resulted in a significant reduction in tumor size and weight. In addition, high doses of fenbendazole significantly inhibited the RAS-related signaling pathway in KRAS mutant lung cancer cells.
To evaluate the antitumor effects of fenbendazole, the viability of wild-type and 5-fluorouracil (FFU) resistant SNU-C5 colorectal cancer cells was assessed in vitro using a colony formation assay. In addition, cultures were treated with different concentrations of fenbendazole in the presence or absence of severe hypoxia for 2 h, and yield-corrected surviving fractions were calculated.
In the presence of hypoxia, fenbendazole was found to significantly reduce the viability of SNU-C5 and SNU-C5/5FUR cells by causing a G2/M arrest as well as inducing apoptosis. In addition, fenbendazole caused apoptosis through p53-mediated pathways in wild-type but not mutant p53 cells and partly induced necroptosis via autophagy and ferroptosis in both cells. However, the phosphorylation of MLKL was not affected by fenbendazole treatment.