Effects of cholesterol, C-reactive protein, and interleukin-6 on prostate cancer risk in a population of African ancestry

Cholesterol metabolism: physiological regulation and diseases

Cholesterol homeostasis is crucial for cellular and systemic function. The disorder of cholesterol metabolism not only accelerates the onset of cardiovascular disease (CVD) but is also the fundamental cause of other ailments. The regulation of cholesterol metabolism in the human is an extremely complex process. Due to the dynamic balance between cholesterol synthesis, intake, efflux and storage, cholesterol metabolism generally remains secure. Disruption of any of these links is likely to have adverse effects on the body. At present, increasing evidence suggests that abnormal cholesterol metabolism is closely related to various systemic diseases. However, the exact mechanism by which cholesterol metabolism contributes to disease pathogenesis remains unclear, and there are still unknown factors. In this review, we outline the metabolic process of cholesterol in the human body, especially reverse cholesterol transport (RCT). Then, we discuss separately the impact of abnormal cholesterol metabolism on common diseases and potential therapeutic targets for each disease, including CVD, tumors, neurological diseases, and immune system diseases. At the end of this review, we focus on the effect of cholesterol metabolism on eye diseases. In short, we hope to provide more new ideas for the pathogenesis and treatment of diseases from the perspective of cholesterol.

Plasma total cholesterol concentration and risk of higher-grade prostate cancer: A nested case-control study and a dose-response meta-analysis

Our previous publication found an increased risk of higher-grade (Gleason sum ≥7) prostate cancer for men with high total cholesterol concentration (≥200 mg/dl) in the Health Professionals Follow-up Study (HPFS). With additional 568 prostate cancer cases, we are now able to investigate this association in more detail. For the nested case-control study, we included 1260 men newly diagnosed with prostate cancer between 1993 and 2004, and 1328 controls. For the meta-analyses, 23 articles studied the relationship between total cholesterol level and prostate cancer incidence were included. Logistic regression models and dose-response meta-analysis were performed. An increased risk of higher-grade (Gleason sum ≥4 + 3) prostate cancer for high vs low quartile of total cholesterol level was observed in the HPFS (ORmultivariable  = 1.56; 95% CI = 1.01-2.40). This finding was compatible with the association noted in the meta-analysis of highest vs lowest group of total cholesterol level, which suggested a moderately increased risk of higher-grade prostate cancer (Pooled RR =1.21; 95%CI: 1.11-1.32). Moreover, the dose-response meta-analysis indicated that an increased risk of higher-grade prostate cancer occurred primarily at total cholesterol levels ≥200 mg/dl, where the RR was 1.04 (95%CI: 1.01-1.08) per 20 mg/dl increase in total cholesterol level. However, total cholesterol concentration was not associated with the risk of prostate cancer overall either in the HPFS or in the meta-analysis. Our primary finding, as well as the result of the meta-analysis suggested a modest increased risk of higher-grade prostate cancer, at total cholesterol concentrations exceeding 200 mg/dl.

The Role of C-Reactive Protein in the Prognosis of Prostate Cancer: A Meta-Analysis

Objective

To investigate the role of C-reactive protein (CRP) in the prognosis of prostate cancer (PCa).

Methods

The studies related to C-reactive protein and prostate cancer were searched by computer, including PubMed and Web of Science. The retrieval time was from the establishment of the database to August 2022. QUADAS score was employed to assess the studies' quality, funnel plot was employed to analyze the bias of the included studies, and RevMan and STATA statistical software programs were used to draw forest maps to represent the analysis results.

Results

In the initial examination, 432 articles were obtained. After removing the duplicate articles, reading the abstract and theme, and then reading the full text, 12 articles finally met the inclusion criteria. The results revealed that serum C-reactive protein (CRP) levels were associated with overall survival (OS) in patients with PCa (OR = 1.47 [1.19, 1.82], P < 0.05), and patients with high CRP levels had an increased risk of developing prostate cancer (HR = 0.26, 95% CI: 0.23, 0.29). However, there was no obvious difference in circulating CRP levels between patients with prostate cancer and healthy controls (P > 0.05).

Conclusions

CRP levels are associated with PCa patients' OS. High CRP levels have an elevated incidence of PCa, but there was no obvious distinction in circulating CRP levels between patients with prostate cancer and healthy controls. Therefore, C-reactive protein has certain reference value for judging the prognosis of prostate cancer.

Tissue cholesterol metabolism and prostate cancer aggressiveness: Ethno-geographic variations

BACKGROUND

Prostate cancer (PCa) is more frequent and more aggressive in populations of African descent than in Caucasians. Since the fatty acid composition of peri-prostatic adipose tissue (PPAT) has been shown to differ according to the ethno-geographic origin and is involved in PCa aggressiveness, we aimed to analyze the cholesterol content of PPAT from Caucasian and African-Caribbean patients, in correlation with markers of disease aggressiveness and cholesterol metabolism in cancer tissues.

METHODS

The quantification of cholesterol in PPAT was analyzed in 52 Caucasian and 52 African-Caribbean PCa patients, with in each group 26 indolent tumors (ISUP Group1 and pT2) and 26 potentially aggressive tumors (ISUP Group 3-5 and/or pT3). The expression of proteins involved in cholesterol metabolism was analyzed by immunohistochemistry on cancer tissue samples included in tissue microarrays.

RESULTS

The amount of cholesterol esters was lower in PPAT from African-Caribbean patients compared with Caucasians, without any correlation with markers of disease aggressiveness. In cancer tissues from African-Caribbean patients, the expression of ABCA1 (involved in cholesterol efflux) was decreased, and that of SREBP-2 (involved in cholesterol uptake) was increased. In both groups of patients, SREBP-2 expression was strongly associated with that of Zeb1, a key player in the epithelial-to-mesenchymal transition (EMT) process.

CONCLUSION

These results suggest that cholesterol metabolism differs according to the ethno-geographic origin, in both PPAT and cancer tissues. In African-Caribbeans, the orientation towards accumulation of cholesterol in cancer cells is associated with a more frequent state of EMT, which may promote PCa aggressiveness in this population.

Relationship between Circulating Lipids and Cytokines in Metastatic Castration-Resistant Prostate Cancer

Simple Summary

Lipids (fatty substances) and cytokines are molecules that affect how the immune response works. The measurement of the amounts of lipids and cytokines in blood might give clues about how prostate cancers grow or respond to treatment. This study looked at the blood levels of lipids and cytokines in men with advanced prostate cancer that was growing despite standard treatment (metastatic castration-resistant prostate cancer, mCRPC). We found that certain lipids were consistently associated with poorer clinical outcome, while cytokines were not. The levels of a type of lipid (ceramide) were associated with some cytokines. This lipid is known to activate the immune system and is associated with poor outcomes in mCRPC. A change in lipid profiles was associated with better response to treatment. Overall, our findings suggest that blood lipids might be more informative than cytokines, might influence the immune response, and might help predict treatment response.

Abstract

Circulating lipids or cytokines are associated with prognosis in metastatic castration-resistant prostate cancer (mCRPC). This study aimed to understand the interactions between lipid metabolism and immune response in mCRPC by investigating the relationship between the plasma lipidome and cytokines. Plasma samples from two independent cohorts of men with mCRPC (n = 146, 139) having life-prolonging treatments were subjected to lipidomic and cytokine profiling (290, 763 lipids; 40 cytokines). Higher baseline levels of sphingolipids, including ceramides, were consistently associated with shorter overall survival in both cohorts, whereas the associations of cytokines with overall survival were inconsistent. Increasing levels of IL6, IL8, CXCL16, MPIF1, and YKL40 correlated with increasing levels of ceramide in both cohorts. Men with a poor prognostic 3-lipid signature at baseline had a shorter time to radiographic progression (poorer treatment response) if their lipid profile at progression was similar to that at baseline, or their cytokine profile at progression differed to that at baseline. In conclusion, baseline levels of circulating lipids were more consistent as prognostic biomarkers than cytokines. The correlation between circulating ceramides and cytokines suggests the regulation of immune responses by ceramides. The association of treatment response with the change in lipid profiles warrants further research into metabolic interventions.

A cross-sectional analysis of investigator needs for non-communicable disease research at the University of the West Indies, Mona

OBJECTIVE

To describe the needs of academic staff conducting non-communicable disease (NCD) research at the University of the West Indies, Mona Campus in Jamaica.

METHODS

Utilizing a cross-sectional design an online survey was created using the research electronic data capture application (REDCap); it was disseminated via email to 708 academic staff members in the Faculties of Medical Sciences and Science & Technology between September and November 2018. Participants were asked to indicate their level of access to expertise, training and equipment for conducting research. Descriptive analysis was conducted using STATA version 14.

RESULTS

Most respondents were women (74.2%), predominantly scientists (33.1%) or specialist physicians (22.6%). Less than 2/3 of respondents reported publishing research findings in peer reviewed journals, with a quarter not disseminating their research findings in any medium. Resources for field research/data collection, epidemiological methods and principles, and data management/data analysis were generally available. However, there was limited access to training, expertise and equipment in emerging techniques for NCD research such as metabolomics, bioinformatics/analysis of large-scale data sets and health economics. Additional challenges included limited access to financing for research, inadequate workspace and poor administrative support for conducting research.

CONCLUSIONS

There is a need for more local research seed funding, stronger administrative support for researchers, and opportunities for training in cutting edge NCD research techniques. Jamaican researchers could benefit from being part of a regional research centre of excellence with critical research skills and equipment that builds research networks and strengthens the NCD research response.