A female patient with advanced non-small cell lung cancer (NSCLC) experienced a rise in her CEA levels after being treated with pembrolizumab. Her family consulted social media websites claiming that fenbendazole (FZ), an anti-parasitic drug for dogs, could reverse tumor progression and cure cancer in humans. They purchased and orally self-administered FZ, which has been shown to have antitumor effects in preclinical models.
To assess the potential antitumor effect of fenbendazole on colorectal cancer cells, wild-type and 5-fluorouracil-resistant SNU-C5 and SNU-C5/5-FUR cells were exposed to fenbendazole for 3 days, followed by apoptosis, cell cycle, and autophagy assays. The results showed that fenbendazole significantly increased the viability of wild-type and 5-fluorouracil-resistant CRC cells, and in addition, induced apoptosis and G2/M arrest of cells via p53-dependent mechanisms.
In addition, fenbendazole triggered autophagy through the Beclin-1-dependent pathway in both wild-type and 5-fluorouracil-resistant cells. Western blot analysis indicated that both Beclin-1 and LC3 protein expression was increased in fenbendazole-treated cells, and the level of GPX4 was suppressed. This correlated with reduced caspase-3-dependent apoptosis, and augmented lipid peroxidation resulting in ferroptosis.
We conclude that fenbendazole is a promising candidate for cancer treatment. Considering that it is widely available as an over-the-counter medication and that it can be used alongside conventional cancer treatments, repurposing this antiparasitic drug for human use has the potential to increase patient access to a safe, effective cancer therapy.fenbendazole for humans