Circulating 27-hydroxycholesterol and Risk of Colorectal Adenomas and Serrated Polyps

Targeted metabolomic profiling as a tool for diagnostics of patients with non-small-cell lung cancer

Lung cancer is referred to as the second most common cancer worldwide and is mainly associated with complex diagnostics and the absence of personalized therapy. Metabolomics may provide significant insights into the improvement of lung cancer diagnostics through identification of the specific biomarkers or biomarker panels that characterize the pathological state of the patient. We performed targeted metabolomic profiling of plasma samples from individuals with non-small cell lung cancer (NSLC, n = 100) and individuals without any cancer or chronic pathologies (n = 100) to identify the relationship between plasma endogenous metabolites and NSLC by means of modern comprehensive bioinformatics tools, including univariate analysis, multivariate analysis, partial correlation network analysis and machine learning. Through the comparison of metabolomic profiles of patients with NSCLC and noncancer individuals, we identified significant alterations in the concentration levels of metabolites mainly related to tryptophan metabolism, the TCA cycle, the urea cycle and lipid metabolism. Additionally, partial correlation network analysis revealed new ratios of the metabolites that significantly distinguished the considered groups of participants. Using the identified significantly altered metabolites and their ratios, we developed a machine learning classification model with an ROC AUC value equal to 0.96. The developed machine learning lung cancer model may serve as a prototype of the approach for the in-time diagnostics of lung cancer that in the future may be introduced in routine clinical use. Overall, we have demonstrated that the combination of metabolomics and up-to-date bioinformatics can be used as a potential tool for proper diagnostics of patients with NSCLC.

Association of egg consumption with colorectal polyp prevalence: findings from the Lanxi Pre-Colorectal Cancer Cohort (LP3C) in China

Eggs contain high-quality protein, lavish vitamins and other bioactive nutrients but are rich in cholesterol. Our study is designed to assess the association of egg intake with polyp prevalence. A total of 7068 participants at a high risk of CRC from the Lanxi Pre-Colorectal Cancer Cohort Study (LP3C) were recruited. A food frequency questionnaire (FFQ) was utilized to obtain dietary data through a face-to-face interview. Cases of colorectal polyps were identified by electronic colonoscopy. The logistic regression model was exploited to achieve odds ratios (ORs) and 95% confidence intervals (CIs). Overall 2064 cases of colorectal polyps were identified in the 2018-2019 survey of LP3C. A positive association of egg consumption with colorectal polyp prevalence was found after the multivariable adjustment [OR_{Q4 vs. Q1} (95% CI): 1.23 (1.05-1.44); P_trend = 0.01]. However, a positive relationship disappeared after further adjustment for dietary cholesterol (P_trend = 0.37), which explained that the harmful role of eggs could be ascribed to the high content of dietary cholesterol. Besides, a positive trend was found between dietary cholesterol and polyp prevalence [OR (95% CI): 1.21 (0.99-1.47); P_trend = 0.04]. Furthermore, replacing 1 egg (50 g d^-1) with an equal amount of total dairy products was related to 11% lower colorectal polyp prevalence [OR (95% CI): 0.89 (0.80-0.99); P = 0.03]. In summary, higher egg consumption was correlated with a higher polyp prevalence among the Chinese population at a high risk of CRC, which was ascribed to the high content of dietary cholesterol in eggs. Besides, individuals with the highest dietary cholesterol tended to have a higher polyp prevalence. Reducing the consumption of eggs and replacing eggs with total dairy products as alternative protein sources may prevent the occurrence of polyps in China.

Selected plasma oxysterols as a potential multi-marker biosignature panel for Behçet's Disease

Clinical, genetic, and medical evidence has shown the inflammatory vasculitis aspect of Behçet's Disease (BD). Whereas oxysterols are vital factors in inflammation and oxidative stress, it is still unknown whether they are involved in the pathophysiology of BD. The current study aims to explore the profile of oxysterols in plasma of BD patients. Thirty patients diagnosed with BD and forty healthy controls matched for age and gender were included. Results showed that the cholestane-3β,5α,6β-triol, 27-hydroxycholesterol (27-OHC) and cholestanol levels were higher in BD than controls. In addition, plasma levels of 7-ketocholesterol (7-KC) and 25-hydroxycholesterol (25-OHC) were lower in BD patient. However, levels of 24S-hydroxycholesterol (24-OHC) did not significantly differ. For BD patients, the plasma 7-KC level was negatively correlated with the BD activity index (BDAI) while 27-OHC was positively correlated with high-sensitivity C-reactive protein (hs-CRP) in patients with active course of the disease. According to ROC analysis, a remarkable increase in the area under the curve (AUC) with a higher sensitivity (Se) and specificity (Sp) for 7-KC, 25-OHC and 27-OHC combined markers was observed. The present study indicated that the identification of the predictive value of these three-selected biomarkers related to oxidative stress and inflammation in patients should lead to a better identification of the etiological mechanism of BD.

Association of demographic and health characteristics with circulating oxysterol concentrations

BACKGOUND

Circulating oxysterols, cholesterol metabolites with important signaling functions, are increasingly being recognized as candidate biomarkers for several diseases, but associations with demographic and health characteristics remain poorly described.

OBJECTIVE

This study aims to characterize associations of major circulating oxysterols with sex, age, race/ethnicity, body mass index (BMI), lifestyle factors, and use of common medications.

METHODS

We measured plasma concentrations of 27-hydroxycholesterol (27-OHC), 25-hydroxycholesterol (25-OHC), 24(S)-hydroxycholesterol (24(S)-OHC), 7ɑ-hydroxycholesterol (7ɑ-OHC), and 4β-hydroxycholesterol (4β-OHC) from 1,440 participants of a completed clinical trial for the chemoprevention of colorectal adenomas. Adjusted percent difference in means were calculated using linear regression.

RESULTS

Women had 18% (95% CI, 14%, 22%) lower 27-OHC and 21% (15%, 27%) higher 4β-OHC than men. Blacks had 15% (7%, 23%) higher 4β-OHC than Non-Hispanic Whites, and Asian or Pacific Islanders had 19% (2%, 35%) higher 7ɑ-OHC than Non-Hispanic Whites. Individuals of BMI ≥35 kg/m2 had 33% (25%, 41%) lower 4β-OHC than those <25 kg/m2. Current smokers had 15% (5%, 24%) higher 7ɑ-OHC than never smokers, and daily alcohol drinkers had 17% (10%, 24%) higher 7ɑ-OHC than never drinkers. Statin use was associated with lower concentrations of all 5 oxysterols. Differences in mean <15% were found for characteristics such as age, total dietary energy intake, physical activity, diabetes, and anti-inflammatory drug use.

CONCLUSION

Circulating oxysterols are uniquely associated with multiple demographic and health characteristics.

Role of 27-hydroxycholesterol and its metabolism in cancer progression: Human studies

Direct translation of findings achieved in experimental cell or animal models to humans is quite a difficult task. We focused here only on the epidemiological and ex vivo human studies so far available about the role of 27-hydroxycholesterol (27OHC) and related metabolism in cancer development. Some studies point to an adverse effect of 27OHC in breast cancer, based on the oxysterol's recognized ability to bind to and modulate estrogen receptors. The detrimental role of this side chain oxysterol would be evident in cancer progression, mainly in post-menopausal women and in an advanced stage of the disease. Other human researches, however, would rather correlate 27OHC intra-tumoral levels to a better prognosis. The analyses on human prostate cancer specimens performed to date are all against a detrimental contribution of 27OHC, rather suggesting interesting anti-prostate cancer effects exerted by this oxysterol. Finally, an increased 27OHC synthesis on the contrary seems to favour progression of late stage cancers in colon, brain and thyroid tissues, as found for breast cancer, possibly due to pro-inflammatory and pro-survival signalling triggered by disproportionate amounts of this oxysterol.