Altered Saturated and Monounsaturated Plasma Phospholipid Fatty Acid Profiles in Adult Males with Colon Adenomas

Abstract

Background Altered lipid metabolism and plasma fatty acid (FA) levels are associated with colorectal cancer (CRC). Obesity and elevated waist circumference (WC) increase the likelihood of developing precancerous colon adenomas. Methods Venous blood was collected from 126 males, ages 48 to 65 years, who received routine colonoscopies. Plasma phospholipid (PPL) FAs were isolated, derivatized, and then analyzed using gas chromatography. Odds ratios (ORs) and 95% confidence intervals were determined using polytomous logistic regression after adjusting for confounding factors (i.e. age, smoking, WC, and BMI). Results PPL palmitic acid (PA) was inversely correlated with the presence of colon adenomas (p = 0.01). For each unit increase in palmitoleic acid (OR: 3.75, p = 0.04) or elaidic acid (OR: 2.92, p = 0.04) an individual was more likely to have adenomas relative to no colon polyps. Higher enzyme activity estimates (EAEs) of stearoyl-CoA desaturase-1 (SCD-1, p = 0.02) and elongation of very long chain-6 (Elovl-6, p = 0.03) were associated with an individual being approximately 1.5 times more likely to have an adenoma compared to no polyps. Conclusions PPL FAs and EAEs, which have previously been associated with CRC, are significantly different in those with adenomas when compared to those without polyps. PPL PA, elaidic acid, and SCD-1 and Elovl-6 EAEs are associated with adenomas independent of BMI and WC. Impact PPL PA, elaidic acid, and SCD-1 and Elovl-6 EAEs are associated with adenomas even after adjusting for obesity-related risk factors and may function as novel biomarkers of early CRC risk.

Hyper-Elongation in Colorectal Cancer Tissue – Cerotic Acid is a Potential Novel Serum Metabolic Marker of Colorectal Malignancies

“…Moreover, our findings suggest that cerotic acid found in sera of CRC patients is a product of FA hyper-elongation in tumor tissue, rather than a marker of peroxisomal metabolic disorders. This hypothesis is also supported by the results of a recent study conducted by Pickens et al [29] who found that higher ELOVL6 activity estimates in blood are associated with increased risk of colon adenoma. All this evidence points to serum cerotic acid as a strong candidate for specific metabolic marker of CRC.…”

Elaidic Acid, a <b><i>Trans</i></b>-Fatty Acid, Enhances the Metastasis of Colorectal Cancer Cells

“…Other studies have argued against these effects by showing that a diet consisting of 25% EA does not enhance colon carcinogenesis in female rats [23] . However, plasma concentration of EA is higher in colon adenoma patients than that in healthy controls [24] . Moreover, EA administration enhances cancer development in Apc Min/+ mice [25] .…”

Pro-metastatic intracellular signaling of the elaidic trans fatty acid

“…Compared with patients in the lowest quartile of TFA consumption, those in the highest quartile showed an increased odds ratio of 1.86 for the prevalence of colorectal adenomas (9). Moreover, elaidic acid (EA), the major TFA (10), is increased in the plasma of colon adenoma patients (11). Additionally, EA promotes colon carcinogenesis in Min mice (12) and induces the proliferation of Ehrlich ascites sarcoma cells (13).…”