Very long-chain fatty acids are accumulated in triacylglycerol and nonesterified forms in colorectal cancer tissues

Abstract

Colorectal cancer (CRC) is a major cancer, and its precise diagnosis is especially important for the development of effective therapeutics. In a series of metabolome analyses, the levels of very long chain fatty acids (VLCFA) were shown to be elevated in CRC tissues, although the endogenous form of VLCFA has not been fully elucidated. In this study we analyzed the amount of nonesterified fatty acids, acyl-CoA species, phospholipids and neutral lipids such as cholesterylesters using liquid-chromatography–mass spectrometry. Here we showed that VLCFA were accumulated in triacylglycerol (TAG) and nonesterified forms in CRC tissues. The levels of TAG species harboring a VLCFA moiety (VLCFA-TAG) were significantly correlated with that of nonesterified VLCFA. We also showed that the expression level of elongation of very long-chain fatty acids protein 1 (ELOVL1) is increased in CRC tissues, and the inhibition of ELOVL1 decreased the levels of VLCFA-TAG and nonesterified VLCFA in CRC cell lines. Our results suggest that the upregulation of ELOVL1 contributes to the accumulation of VLCFA-TAG and nonesterified VLCFA in CRC tissues.