Comprehensive Investigation on Associations between Dietary Intake and Blood Levels of Fatty Acids and Colorectal Cancer Risk

Eicosapentaenoic acid enhances intestinal stem cell-mediated colonic epithelial regeneration by activating the LSD1-WNT signaling pathway

INTRODUCTION

Inflammatory bowel disease (IBD) is often associated with impaired proliferation and differentiation of intestinal stem cells (ISCs). Eicosapentaenoic acid (EPA), which is predominantly found in fish oil, has been recognized for its intestinal health benefits, although the potential mechanisms are not well understood.

OBJECTIVES

This study aimed to investigate the regulatory role and mechanism of EPA in colonic epithelial regeneration, specifically from the perspective of ISCs.

METHODS

Wild-type mice whose diet was supplemented with 5% EPA-enriched fish oil were subjected to dextran sulfate sodium (DSS) to induce colitis. We utilized intestinal organoids, ISC-specific lysine-specific demethylase 1 (LSD1) knockout mice, and WNT inhibitor-treated mice to explore how EPA influences ISC proliferation and differentiation. ISC proliferation, differentiation and apoptosis were assessed using tdTomato and propidium iodide tracer testing, histological analyses, and immunofluorescence staining.

RESULTS

EPA treatment significantly mitigated the symptoms of DSS-induced acute colitis, as evidenced by lower body weight loss and decreased disease activity index, histological scores and proinflammatory cytokine levels. Additionally, EPA increased the numbers of proliferative cells, absorptive cells, goblet cells, and enteroendocrine cells, which enhanced the regeneration of intestinal epithelium. Pretreatment with EPA increased ISC proliferation and differentiation, and protected against TNF-α-induced cell death in intestinal organoids. Mechanistically, EPA upregulated G protein-coupled receptor 120 (GPR120) to induce LSD1 expression, which facilitated ISC proliferation and differentiation in organoids. ISC-specific ablation of LSD1 negated the protective effect of EPA on DSS-induced colitis in mice. Moreover, EPA administration activated the WNT signaling pathway downstream of LSD1 in ISCs, while inhibiting WNT signaling abolished the beneficial effects of EPA.

CONCLUSIONS

These findings demonstrate that EPA promotes ISC proliferation and differentiation, thereby enhancing colonic epithelial regeneration through the activation of LSD1-WNT signaling. Consequently, dietary supplementation with EPA represents a promising alternative therapeutic strategy for managing IBD.

Association of dietary patterns derived by reduced-rank regression with colorectal cancer risk and mortality

PURPOSE

Unhealthy dietary patterns contribute to an increased risk of colorectal cancer (CRC). Limited prior research has used reduced rank regression (RRR) to assess dietary patterns relative to CRC risk. This study aimed to identify dietary patterns derived by RRR and assess their associations with CRC risk and mortality.

METHODS

We used data from the multicentre Prostate, Lung, Colorectal, and Ovarian Cancer Screening (PLCO) trial. Dietary intake was assessed using a Dietary History Questionnaire. In the RRR intake of fibre, folate, and the percentage of energy from carbohydrates, saturated and unsaturated fatty acids were used as response variables. Cox models and competing risk survival regression, with age as the time scale, were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for CRC risk and mortality, respectively.

RESULTS

The median follow-up time for CRC risk (n = 1044) and mortality (n = 499) was 9.4 years (Interquartile Range: 8. 0, 10.1) and 16.9 years (11.9, 18.6), respectively. Two dietary patterns were identified: the first was characterised by high carbohydrate, folate and low fatty acid intake, and the second by high fibre and unsaturated fatty acid. Compared to participants in the first tertile of the high fibre and unsaturated fatty acid pattern, those in the third tertile had a lower risk of CRC (HR = 0.88; 95% CI: 0.76, 1.03), and colon cancer (HR = 0.85; 95% CI: 0.72, 1.01). Conversely, the high carbohydrate, high folate and low fatty acid pattern had no association with CRC outcomes. None of the dietary patterns showed associations with rectal cancer or CRC mortality.

CONCLUSION

A diet enriched with high fibre and unsaturated fatty acids may reduce the risk of CRC. These results highlight the potential protective effect of adequate fibre intake in conjunction with high consumption of unsaturated fatty acids against CRC.

Genetically predicted dietary intake and risks of colorectal cancer: a Mendelian randomisation study

BACKGROUND

Effects of confounders on associations between diet and colorectal cancer (CRC) in observational studies can be minimized in Mendelian randomization (MR) approach. This study aimed to investigate observational and genetically predicted associations between dietary intake and CRC using one-sample MR.

METHODS

Using genetic data of over 93 million variants, we performed a genome-wide association study to find genomic risk loci associated with dietary intake in participants from the UK Biobank. Then we calculated genetic risk scores of diet-related variants and used them as instrumental variables in the two-stage least square MR framework to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for associations. We also performed observational analyses using age as a time-scale in Cox proportional hazard models.

RESULTS

Allele scores were calculated from 399 genetic variants associated with the consumption of of red meat, processed meat, poultry, fish, milk, cheese, fruits, vegetables, coffee, tea, and alcohol in participants from the UK Biobank. In MR analysis, genetically predicted fruit intake was significantly associated with a 21% decreased risk of CRC (HR = 0.79, 95% CI = 0.66-0.95), and there was a marginally inverse association between vegetable intake and CRC (HR = 0.85, 95% CI = 0.71-1.02). However, null findings were observed in multivariable analysis, with HRs (95% CIs) of 0.99 (0.98-1.01) and 0.99 (0.98-1.00) per increment of daily servings of fruits and vegetables, respectively.

CONCLUSION

Dietary habits were attributable to genetic variations, which can be used as instrumental variables in the MR framework. Our study supported a causal relationship between fruit intake and a decreased risk of CRC and suggested an effective strategy of consuming fruits in the primary prevention of CRC.

Astragaloside IV Ameliorates Colonic Adenomatous Polyps Development by Orchestrating Gut Bifidobacterium and Serum Metabolome

Astragaloside IV (AS-IV), a natural triterpenoid isolated from Astragalus membranaceus, has been used traditionally in Chinese medicine. Previous studies have highlighted its benefits against carcinoma, but its interaction with the gut microbiota and effects on adenomatous polyps are not well understood. This present study investigates the effects of AS-IV on colonic adenomatous polyp (CAP) development in high-fat-diet (HFD) fed [Formula: see text] mice. [Formula: see text] mice were fed an HFD with or without AS-IV or Naringin for 8 weeks. The study assessed CAP proliferation and employed 16S DNA-sequencing and untargeted metabolomics to explore correlations between microbiome and metabolome in CAP development. AS-IV was more effective than Naringin in reducing CAP development, inhibiting colonic proinflammatory cytokines (IL-1β, IL-6, and TNF-α), tumor associated biomarkers (c-Myc, Cyclin D1), and Wnt/β-catenin pathway proteins (Wnt3a, β-catenin). AS-IV also inhibited the proliferative capabilities of human colon cancer cells (HT29, HCT116, and SW620). Multiomics analysis revealed AS-IV increased the abundance of beneficial genera such as Bifidobacterium pseudolongum and significantly modulated serum levels of certain metabolites including linoleate and 2-trans,6-trans-farnesal, which were significantly correlated with the number of CAP. Finally, the anti-adenoma efficacy of AS-IV alone was significantly suppressed post pseudoaseptic intervention in HFD-fed [Formula: see text] mice but could be reinstated following a combined with Bifidobacterium pseudolongum transplant. AS-IV attenuates CAP development in HFD-fed [Formula: see text] mice by regulating gut microbiota and metabolomics, impacting the Wnt3a/β-catenin signaling pathway. This suggests a potential new strategy for the prevention of colorectal cancer, emphasizing the role of gut microbiota in AS-IV's antitumor effects.

Systematic investigation of genetically determined plasma and urinary metabolites to discover potential interventional targets for colorectal cancer

BACKGROUND

We aimed to identify plasma and urinary metabolites related to colorectal cancer (CRC) risk and elucidate their mediator role in the associations between modifiable risk factors and CRC.

METHODS

Metabolite quantitative trait loci were derived from 2 published metabolomics genome-wide association studies, and summary-level data were extracted for 651 plasma metabolites and 208 urinary metabolites. Genetic associations with CRC were obtained from a large-scale genome-wide association study meta-analysis (100 204 cases, 154 587 controls) and the FinnGen cohort (4957 cases, 304 197 controls). Mendelian randomization and colocalization analyses were performed to evaluate the causal roles of metabolites in CRC. Druggability evaluation was employed to prioritize potential therapeutic targets. Multivariable Mendelian randomization and mediation estimation were conducted to elucidate the mediating effects of metabolites on the associations between modifiable risk factors and CRC.

RESULTS

The study identified 30 plasma metabolites and 4 urinary metabolites for CRC. Plasma sphingomyelin and urinary lactose, which were positively associated with CRC risk, could be modulated by drug interventions (ie, olipudase alfa, tilactase). Thirteen modifiable risk factors were associated with 9 metabolites, and 8 of these modifiable risk factors were associated with CRC risk. These 9 metabolites mediated the effect of modifiable risk factors (Actinobacteria, body mass index, waist to hip ratio, fasting insulin, smoking initiation) on CRC.

CONCLUSION

This study identified key metabolite biomarkers associated with CRC and elucidated their mediator roles in the associations between modifiable risk factors and CRC. These findings provide new insights into the etiology and potential therapeutic targets for CRC and the etiological pathways of modifiable environmental factors with CRC.

Dietary Factors and the Risk of Colorectal Cancer: A Mendelian Randomization Study

OBJECTIVE

To examine the causal association between 15 dietary factors and the incidence of colorectal cancer through the application of Mendelian randomization methodology.

METHODS

The data associated with 15 dietary factors were derived from the IEU OPEN GWAS database, and the colorectal cancer data were sourced from the FinnGen database. The Inverse Variance Weighting method was the principal research method. Sensitivity analyses were implemented to affirm the robustness of the findings. Additionally, we conducted multivariable Mendelian randomization analyses to adjust for the intake of ω-3 and ω-6 polyunsaturated fatty acids.

RESULTS

In our research, we observed suggestive causal relationships between genetically predicted water intake and the reduced risk of colorectal cancer (OR = 0.54; 95% CI= 0.31 ∼ 0.93; p = 0.028); genetically predicted ω-3 PUFA intake (OR = 1.17; 95% CI= 1.05 ∼ 1.30; p = 0.005) were suggestively associated with the increased risk of colorectal cancer. In the multivariable Mendelian randomization analysis, the effect of ω-3 PUFA intake remains significant after adjusting for the influence of ω-6 PUFA intake. Horizontal pleiotropy was not present in this study.

CONCLUSIONS

There exists a suggestive causal association between increased water intake and decreased risk of colorectal cancer, while ω-3 PUFA intake are suggestive linked to the increased risk of colorectal cancer.

DPP3 promotes breast cancer tumorigenesis by stabilizing FASN and promoting lipid synthesis

DPP3, a dipeptidyl peptidase, participates in a variety of pathophysiological processes. DPP3 is upregulated in cancer and might serve as a key factor in the tumorigenesis and progression of various malignancies. However, its specific role and molecular mechanism are still unknown. In this study, the expression of DPP3 in breast cancer tissues is analyzed using TCGA database. Kaplan-Meier survival analysis is performed to estimate the effect of DPP3 on the survival outcomes. To explore the biological function and mechanisms of DPP3 in breast cancer, biochemical and cell biology assays are conducted in vitro. DPP3 expresses at a higher level in breast cancer tissues than that in adjacent tissues in both TCGA database and clinical samples. Patients with high expression of DPP3 have poor survival outcomes. The proliferation and migration abilities of tumor cells with stable DPP3 knockout in breast cancer cell lines are significantly inhibited, and apoptosis is increased in vitro. GSEA analysis shows that DPP3 can affect lipid metabolism and fatty acid synthesis in tumors. Subsequent experiments show that DPP3 could stabilize FASN expression and thus promote fatty acid synthesis in tumor cells. The results of the metabolomic analysis also confirm that DPP3 can affect the content of free fatty acids. This study demonstrates that DPP3 plays a role in the reprogramming of fatty acid metabolism in tumors and is associated with poor prognosis in breast cancer patients. These findings will provide a new therapeutic target for the treatment of breast cancer.

Association between pre-diagnostic circulating lipid metabolites and colorectal cancer risk: a nested case-control study in the European Prospective Investigation into Cancer and Nutrition (EPIC)

BACKGROUND

Altered lipid metabolism is a hallmark of cancer development. However, the role of specific lipid metabolites in colorectal cancer development is uncertain.

METHODS

In a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC), we examined associations between pre-diagnostic circulating concentrations of 97 lipid metabolites (acylcarnitines, glycerophospholipids and sphingolipids) and colorectal cancer risk. Circulating lipids were measured using targeted mass spectrometry in 1591 incident colorectal cancer cases (55% women) and 1591 matched controls. Multivariable conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between concentrations of individual lipid metabolites and metabolite patterns with colorectal cancer risk.

FINDINGS

Of the 97 assayed lipids, 24 were inversely associated (nominally p < 0.05) with colorectal cancer risk. Hydroxysphingomyelin (SM (OH)) C22:2 (ORper doubling 0.60, 95% CI 0.47-0.77) and acylakyl-phosphatidylcholine (PC ae) C34:3 (ORper doubling 0.71, 95% CI 0.59-0.87) remained associated after multiple comparisons correction. These associations were unaltered after excluding the first 5 years of follow-up after blood collection and were consistent according to sex, age at diagnosis, BMI, and colorectal subsite. Two lipid patterns, one including 26 phosphatidylcholines and all sphingolipids, and another 30 phosphatidylcholines, were weakly inversely associated with colorectal cancer.

INTERPRETATION

Elevated pre-diagnostic circulating levels of SM (OH) C22:2 and PC ae C34:3 and lipid patterns including phosphatidylcholines and sphingolipids were associated with lower colorectal cancer risk. This study may provide insight into potential links between specific lipids and colorectal cancer development. Additional prospective studies are needed to validate the observed associations.

FUNDING

World Cancer Research Fund (reference: 2013/1002); European Commission (FP7: BBMRI-LPC; reference: 313010).

Plasma free fatty acid levels in cervical cancer: concurrent chemoradiotherapy improves abnormal profile

Background: Epidemiology has demonstrated that plasma free fatty acids (FFAs) can prevent the development of cancer. Our study sought to evaluate the relationship between plasma (FFA) levels and cervical cancer. Methods: In recent years, metabolomics-based approaches have been recognized as an emerging tool, so we examined the plasma FFA profiles of 114 patients with cervical cancer and 151 healthy people using liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. Results: The data results were analyzed by multifactorial binary logistic regression analysis, and it was found that palmitic acid, docosahexaenoic acid (DHA), and total ω-3 fatty acids were negatively correlated with the risk of cervical cancer; whereas tetracosanoic acid was positively correlated with the risk of cervical cancer (OR, 1.026; 95% CI, 1.013-1.040; p < 0.001). Dynamic follow-up of 40 cervical cancer patients who successfully completed CCRT revealed that most fatty acid levels tended to increase after the end of treatment, except for palmitic and stearic acid levels, which were lower than before treatment. Conclusion: Plasma FFA profiles were altered in cervical cancer patients, which may be related to abnormal fatty acid metabolism in cervical cancer. The described changes in fatty acid profiles during CCRT may be related to the good functioning of CCRT. Further studies on plasma FFA composition and its changes due to CCRT in patients with cervical cancer are warranted.

Integrative polygenic analysis of the protective effects of fatty acid metabolism on disease as modified by obesity

Dysregulation of fatty acid metabolites can play a crucial role in the progression of complex diseases, such as cardiovascular disease, digestive diseases, and metabolic diseases. Metabolites can have either protective or risk effects on a disease; however, the details of such associations remain contentious. In this study, we demonstrate an integrative PheWAS approach to establish high confidence, causally suggestive of metabolite-disease associations for three fatty acid metabolites, namely, omega-3 fatty acids, omega-6 fatty acids, and docosahexaenoic acid, for 1,254 disease endpoints. Metabolite-disease associations were established if there was a concordant direction of effect and significance for metabolite level and genetic risk score for the metabolite. There was enrichment for metabolite associations with diseases of the respiratory system for omega-3 fatty acids, diseases of the circulatory system and endocrine system for omega-6 fatty acids, and diseases of the digestive system for docosahexaenoic acid. Upon performing Mendelian randomization on a subset of the outcomes, we identified 3, 6, and 15 significant diseases associated with omega-3 fatty acids, omega-6 fatty acids, and docosahexaenoic acid, respectively. We then demonstrate a class of prevalence-risk relationships indicative of (de)canalization of disease under high and low fatty acid metabolite levels. Finally, we show that the interaction between the metabolites and obesity demonstrates that the degree of protection afforded by fatty acid metabolites is strongly modulated by underlying metabolic health. This study evaluated the disease architectures of three polyunsaturated fatty acids (PUFAs), which were validated by several PheWAS modes of support. Our results not only highlight specific diseases associated with each metabolite but also disease group enrichments. In addition, we demonstrate an integrative PheWAS methodology that can be applied to other components of the human metabolome or other traits of interest. The results of this study can be used as an atlas to cross-compare genetic with non-genetic disease associations for the three PUFAs investigated. The findings can be explored through our R shiny app at https://pufa.biosci.gatech.edu.

High and low dietary fiber consumption and cancer risk: a comprehensive umbrella review with meta-meta-analysis involving meta-analyses of observational epidemiological studies

It is a well-known fact that dietary fiber is recognized as one of the essential components of a healthy diet. The aim of this paper was to investigate the impact of dietary fiber on the incidence and mortality of various types of cancer, the current evidence in this field, and the biases of this evidence using the meta-meta-analysis method. We identified meta-analyses that particularly focused on the association between dietary fiber consumption and the risk/mortality of cancer. A structured and comprehensive computer literature search was undertaken in the electronic databases PubMed/Medline, Web of Science (WoS), and Scopus. The search yielded a total of 25 papers and 28 reports. In the pooled analysis, higher dietary fiber consumption was associated with a 22% lower cancer risk (OR = 0.78, 95% CI: 0.74-0.83, p < 0.001) and a 17% lower mortality (RR = 0.83, 95% CI: 0.78-0.90, p < 0.001). In the secondary meta-meta-analysis, it was observed that there was an inverse association between dietary fiber intake and digestive tract cancers (OR = 0.68, 95% CI: 0.62-0.76) and breast cancer (OR = 0.92, 95% CI: 0.90-0.94). Taken together, this paper suggests that promoting a high-fiber diet may be an effective strategy for the prevention and management of cancer.

Pentadecanoic Acid (C15:0), an Essential Fatty Acid, Shares Clinically Relevant Cell-Based Activities with Leading Longevity-Enhancing Compounds

Pentadecanoic acid (C15:0) is an essential odd-chain saturated fatty acid with broad activities relevant to protecting cardiometabolic, immune, and liver health. C15:0 activates AMPK and inhibits mTOR, both of which are core components of the human longevity pathway. To assess the potential for C15:0 to enhance processes associated with longevity and healthspan, we used human cell-based molecular phenotyping assays to compare C15:0 with three longevity-enhancing candidates: acarbose, metformin, and rapamycin. C15:0 (n = 36 activities in 10 of 12 cell systems) and rapamycin (n = 32 activities in 12 of 12 systems) had the most clinically relevant, dose-dependent activities. At their optimal doses, C15:0 (17 µM) and rapamycin (9 µM) shared 24 activities across 10 cell systems, including anti-inflammatory (e.g., lowered MCP-1, TNFα, IL-10, IL-17A/F), antifibrotic, and anticancer activities, which are further supported by previously published in vitro and in vivo studies. Paired with prior demonstrated abilities for C15:0 to target longevity pathways, hallmarks of aging, aging rate biomarkers, and core components of type 2 diabetes, heart disease, cancer, and nonalcoholic fatty liver disease, our results support C15:0 as an essential nutrient with activities equivalent to, or surpassing, leading longevity-enhancing candidate compounds.

Food Intake and Colorectal Cancer

Colorectal cancer (CRC) accounts for considerable mortalities worldwide. Several modifiable risk factors, including a high intake of certain foods and beverages can cause CRC. This review summarized the latest findings on the intake of various foods, nutrients, ingredients, and beverages on CRC development, with the objective of classifying them as a risk or protective factor. High-risk food items include red meat, processed meat, eggs, high alcohol consumption, sugar-sweetened beverages, and chocolate candy. Food items that are protective include milk, cheese and other dairy products, fruits, vegetables (particularly cruciferous), whole grains, legumes (particularly soy beans), fish, tea (particularly green tea), coffee (particularly among Asians), chocolate, and moderate alcohol consumption (particularly wine). High-risk nutrients/ingredients include dietary fat from animal sources and industrial trans-fatty acids (semisolid/solid hydrogenated oils), synthetic food coloring, monosodium glutamate, titanium dioxide, and high-fructose corn sirup. Nutrients/ingredients that are protective include dietary fiber (particularly from cereals), fatty acids (medium-chain and odd-chain saturated fatty acids and highly unsaturated fatty acids, including omega-3 polyunsaturated fatty acids), calcium, polyphenols, curcumin, selenium, zinc, magnesium, and vitamins A, C, D, E, and B (particularly B6, B9, and B2). A combination of micronutrients and multi-vitamins also appears to be beneficial in reducing recurrent adenoma incidence.

Free-fatty acid receptor-1 (FFA1/GPR40) promotes papillary RCC proliferation and tumor growth via Src/PI3K/AKT/NF-κB but suppresses migration by inhibition of EGFR, ERK1/2, STAT3 and EMT

BACKGROUND

Papillary renal cell carcinoma (pRCC) is a highly metastatic genitourinary cancer and is generally irresponsive to common treatments used for the more prevalent clear-cell (ccRCC) subtype. The goal of this study was to examine the novel role of the free fatty-acid receptor-1 (FFA1/GPR40), a cell-surface expressed G protein-coupled receptor that is activated by medium-to-long chained dietary fats, in modulation of pRCC cell migration invasion, proliferation and tumor growth.

METHODS

We assessed the expression of FFA1 in human pRCC and ccRCC tumor tissues compared to patient-matched non-cancerous controls, as well as in RCC cell lines. Using the selective FFA1 agonist AS2034178 and the selective FFA1 antagonist GW1100, we examined the role of FFA1 in modulating cell migration, invasion, proliferation and tumor growth and assessed the FFA1-associated intracellular signaling mechanisms via immunoblotting.

RESULTS

We reveal for the first time that FFA1 is upregulated in pRCC tissue compared to patient-matched non-cancerous adjacent tissue and that its expression increases with pRCC cancer pathology, while the inverse is seen in ccRCC tissue. We also show that FFA1 is expressed in the pRCC cell line ACHN, but not in ccRCC cell lines, suggesting a unique role in pRCC pathology. Our results demonstrate that FFA1 agonism promotes tumor growth and cell proliferation via c-Src/PI3K/AKT/NF-κB and COX-2 signaling. At the same time, agonism of FFA1 strongly inhibits migration and invasion, which are mechanistically mediated via inhibition of EGFR, ERK1/2 and regulators of epithelial-mesenchymal transition.

CONCLUSIONS

Our data suggest that FFA1 plays oppositional growth and migratory roles in pRCC and identifies this receptor as a potential target for modulation of pathogenesis of this aggressive cancer.