Authors: Sebastian Dennis-Beron, Future Science Group
Recently published in Molecular Cancer Therapeutics, a preclinical study carried out by researchers at UC Davis (CA, USA) reports that docosahexaenoic acid (DHA), commonly found in fish oil supplements, reduced renal cell carcinoma growth, vascularization and invasiveness when combined with regorafenib.
Kidney cancers can mutate to develop resistance to regorafenib, a tyrosine kinase inhibitor. “Most renal cell carcinomas learn to escape therapy after a couple of years,” stated lead investigator Robert Weiss, (UC Davis). “A simple additive, which is completely nontoxic, could have a positive effect on disease, even rescuing regorafenib and similar therapies from resistance.”
Weiss and colleagues were aware that a DHA metabolite, epoxydocosapentaenoic acid (EDP) could reduce the cancer’s ability for vascular growth and further invasion. This metabolite, however, is broken down by soluble epoxide hydrolase (sEH). Their previous study had highlighted that regorafenib could block sEH. Therefore, by blocking sEH with the drug, all added DHA went towards forming EDP, which contributed to the anticancer effect.
In order to assess whether DHA complemented regorafenib, the team studied the combination in both cancer cell lines and human tumors in mice. The results demonstrated that combining these compounds killed the renal carcinoma cells in both these models.
The DHA-regorafenib combination specifically reduced tumor growth and angiogenesis by targeting the MAP/ERK kinase and VEGFR protein pathways, respectively.
Weiss cautioned that though these results seem promising, there is no evidence to suggest that the consumption of fish or fish oil supplements alone would have any impact on kidney cancer progression.
“We don’t have any evidence for that so far,” said Weiss. “It would be premature to make that assumption.”
He continued by stating that the results do propose a relatively simple way for patients with advanced kidney cancer to increase the effectiveness of their current treatment. Weiss stated how the next steps could be to encourage oncologists to implement this recommendation in the clinics.