A deworming medication that’s been prescribed to dogs for years could potentially cure cancer, according to researchers. Fenbendazole (methyl [5-(phenylsulfanyl)-1H-benzimidazol-2-yl] carbamate) binds to tubulin, the protein that forms both the micro-skeleton of the cell’s inner structure and highways for transport, cutting off its supply of food and leading it to collapse. It’s the same mechanism by which mebendazole, a similar drug used to treat parasitic infections in humans and animals, kills parasites, including pinworms, tapeworms, hookworms, whipworms and roundworms.
The researchers compared tumor growth in EMT6 cells treated with three daily i.p. injections of fenbendazole, with or without 10 Gy of x-ray radiation. The results showed that fenbendazole alone inhibited tumor growth, but did not alter the sensitivity of the cells to irradiation. When combined with x-rays, however, fenbendazole significantly improved the efficacy of irradiation against the tumors.
The researchers also analyzed whether 5-fluorouracil-resistant SNU-C5 cells, which are more resistant to conventional chemotherapy drugs, were sensitive to fenbendazole treatment. They found that the drug reduced autophagy, enhanced ferroptosis and augmented apoptosis in these cells. They also demonstrated that the apoptotic activity of fenbendazole in these cells does not require p53. fenbendazole stage 4 cancer