Polyunsaturated fatty acids inhibit PI3K activity in a yeast-based model system

Area of Science:

• Biochemistry
• Molecular Biology
• Oncology

Background:

• The phosphatidylinositol 3-kinase (PI3K) pathway is crucial for regulating cell growth, proliferation, migration, and apoptosis.
• Hyperactivity of the PI3K pathway, often due to gene mutation or overexpression, is implicated in numerous cancers, making it a significant pharmacological target.
• Dietary polyunsaturated fatty acids (PUFA) have been suggested to modulate PI3K activity.

Purpose of the Study:

• To investigate the effects of long-chain polyunsaturated n-3 fatty acids on the PI3K/PTEN/Akt pathway using a reconstituted yeast model.
• To determine if PUFA can alleviate the toxic effects associated with PI3K pathway hyperactivity.

Main Methods:

• A yeast-based model was employed to reconstitute the human PI3K/PTEN/Akt pathway.
• The impact of various PUFA on PI3K activity and associated cellular processes was assessed.
• Effects on PI3K catalytic subunit protein levels and phosphatidylinositol 4,5-bisphosphate depletion were measured.

Main Results:

• Various PUFA demonstrated the ability to alleviate toxicity caused by the overexpression of PI3K.
• PUFA did not significantly alter the steady-state levels of PI3K catalytic subunit proteins (p110alpha) in yeast.
• Treatment with PUFA significantly reduced the depletion of phosphatidylinositol 4,5-bisphosphate induced by p110alpha overexpression.

Conclusions:

• Long-chain polyunsaturated n-3 fatty acids can directly inhibit mammalian PI3K activity within an exogenous cellular context (yeast).
• These findings suggest a direct inhibitory effect of PUFA on PI3K, independent of other mammalian factors.
• The results highlight the potential of PUFA, abundant in marine foods and fish oils, as a dietary strategy to target PI3K in cancer therapy.