Oxylipids are potent
lipid mediators associated with
inflammation-induced colon
carcinomas and colon
tumor survival. Therefore, oxylipid profiles may be useful as novel
biomarkers of colon
polyp presence. The aim of this study was to investigate the relationship between plasma non-esterified oxylipids and the presence of colon
polyps. A total of 123 Caucasian men, ages 48 to 65, were categorized into three groups: those with no
polyps, those with one or more hyperplastic
polyps, and those with one or more
adenomas. Plasma non-esterified oxylipids were analyzed using solid phase extraction and quantified using a targeted HPLC tandem mass spectrometric analysis. Statistical analyses included Kruskal-Wallis one-way ANOVA with Dunn's test for multiple comparison and generalized linear models to adjust for confounding factors such as age, anthropometrics, and smoking status. In general, monohydroxy omega-6-derived oxylipids were significantly increased in those with
polyps. Concentrations of
5-hydroxyeicosatetraenoic acid (
HETE) and
11-HETE were significantly higher in those with hyperplastic
polyps and
adenomas compared to those with no
polyps.
Arachidonic acid-derived HETEs were significantly associated with colon
polyp types, even after adjusting for age, smoking, and body mass index or waist circumference in regression models. Since many of these oxylipids are formed through oxygenation by
lipoxygenases (i.e., 5-, 12-, and 15-
HETE, and 15- hydroxyeicosatrienoic
acid [HETrE]) or auto-oxidative reactions (i.e., 11-HETE), this may indicate that
lipoxygenase activity and lipid peroxidation are increased in those with colon
polyps. In addition, since oxylipids such as 5-, 12-, and
15-HETE are signaling molecules involved in
inflammation regulation, these oxylipids may have important functions in
inflammation-associated
polyp presence. Future studies should be performed in a larger cohorts to investigate if these oxylipids are useful as potential
biomarkers of colon
polyps.