Endogenous n-3 polyunsaturated fatty acids prevent azoxymethane-induced colon tumorigenesis in mice fed a high-fat diet

Abstract

Literature suggests important roles of a high-fat diet (HFD) in tumour development, but the underlying mechanisms remain poorly understood. This study assessed the protective effect of n-3 polyunsaturated fatty acids (PUFAs) on HFD-enhanced colon tumours and the underlying mechanism. WT mice were fed a normal fat diet or HFD and Fat-1 mice were fed a HFD for 22 weeks. For weeks 1–6, all mice were intraperitoneally administered AOM weekly. HFD significantly enhanced AOM-induced colon tumorigenesis in WT mice; however, tumour incidence and multiplicity were markedly lower in Fat-1 mice. HFD-triggered tumour development involved the activation of inflammatory signalling pathways, including TNF-α/NF-κB, IL-6/STAT3, and downstream NLRP3/IL-1β pathways and upregulation of β-catenin/c-myc pathway, which is associated with cancer cell proliferation. n-3 PUFAs inhibited colon tumour development and mitigated the changes to the aforementioned inflammatory pathways and oncogenic signalling. We provide experimental evidence for the role of n-3 PUFAs as potential chemopreventive agents against colon cancer.

Keywords

• n-3 polyunsaturated fatty acids
• Fat-1
• Colon tumour
• High fat diet
• Inflammatory pathways