Association of Delta-6-Desaturase Expression with Aggressiveness of Cancer, Diabetes Mellitus, and Multiple Sclerosis: A Narrative Review

Abstract

Background: The phosphatidylinositol 3-kinase/ protein kinase B /mammalian target of rapamycin (PI3K/Akt/<br />mTOR) signaling regulates multiple cellular processes and organizes cell proliferation, survival, and differentiation<br />with the available nutrients, in particular, fatty acids. Polyunsaturated fatty acids (PUFAs) are cytotoxic to cancer cells<br />and play a critical role in the treatment of multiple sclerosis (MS) and diabetes mellitus (DM). PUFAs are produced in<br />the body by desaturases and elongases from dietary essential fatty acids (EFAs), primarily involving delta-6-desaturase<br />(D6D). D6D is a rate-limiting enzyme for maintaining many aspects of lipid homeostasis and normal health. D6D is<br />important to recognize the mechanisms that regulate the expression of this enzyme in humans. A lower level of D6D was<br />seen in breast tumors compared to normal tissues. Interestingly, the elevated serum level of D6D was seen in MS and<br />DM, which explains the critical role of D6D in inflammatory diseases. Methods: We searched databases of PubMed,<br />Web of Science (WOS), Google Scholar, Scopus and related studies by predefined eligibility criteria. We assessed<br />their quality and extracted data. Results: Regarding the mTOR signaling pathway, there is remarkable contributions of<br />many inflammatory diseases to attention to common metabolic pathways are depicted. Of course, we need to have the<br />insights into each disorder and their pathological process. The first step in balancing the intake of EFAs is to prevent<br />the disruption of metabolism and expression of the D6D enzyme. Conclusions: The ω6 and ω3 pathways are two major<br />pathways in the biosynthesis of PUFAs. In both of these, D6D is a vital bifunctional enzyme desaturating linoleic acid<br />or alpha-linolenic acid. Therefore, if ω6 and ω3 EFAs are given together in a ratio of 2: 1, the D6D expression will be<br />down-regulated and normalized.