Linoleic acid, an Omega-6 fatty acid present in seed oils such as soy and carthame oil, as well as in animal products such as pork and eggs, is a nutrient of food origin considered as essential in mammals for the support of many bodily functions. However, the abundance of this fat in Western food has increased considerably in recent decades, in particular with the use of seed oils in fried and ultra-transformed foods.
Several research has suggested that an excessive OMEGA-6 contribution could help explain the increase in the rates of certain diseases, including breast cancer.
This new research reveals that this excessive OMEGA-6 contribution specifically promotes the growth of triple negative breast cancer, a type of cancer very difficult to treat. This discovery requires new dietary but also pharmaceutical strategies against this breast cancer.
The main author, Dr. John Blenis, Cancer Research Professor and Researcher at Weill Cornell Medicine Cancer Center, adds that “this discovery clarifies the link between food fats and cancer, and also makes it possible to better identify patients likely to benefit from specific nutritional recommendations”.
-Linoleic acid activates a tumor growth route
The study First is interested in breast cancer and examines this capacity of omega-6 fatty acids, in particular linoleic acid, the main omega-6 present in Western diet, to stimulate an important tumor growth route sensitive to nutrients, the MTORC1. These works indeed reveal that:
- Linoleic acid active actively MTORC1 in cellular models and breast cancer animals, but only in triple negative subtypes;
- This specific effect of this subtype occurs because polyunsaturated fatty acid forms a complex with the FABP5, a protein produced in large quantities in the negative triple breast tumors, but not in other subtypes of breast cancer;
- This OMEGA-6/ FABP5 complex leads to the assembly and activation of MTORC1, a major regulator of cell metabolism and growth of cancer cells;
- Thus, mouse feeding with triple negative breast cancer with a diet rich in linoleic acid induces an increase in fabp5 rates, then activation of MTORC1 and therefore tumor growth;
- In vitro, there is also an increase in fabp5 and linoleic acid levels in tumors and blood samples from patients recently diagnosed triple negative.
Linoleic acid can therefore play a role in breast cancerbut in a more targeted context than we thought so far, and according to a specific mechanism which, now deciphered, could be inhibited. Finally, the importance of the protein FabP5 in this process also suggests that it could constitute a good “biomarker” to target nutritional and therapeutic interventions aimed at reducing these OMEGA-6 contributions.
Other implications? The activation of the omega-6-FABP5-MTORC1 signaling pathway could play a role in other diseases, we know that this same path can promote the growth of Some subtypes of prostate cancer.
