Omega-3 polyunsaturated fatty acids: moving towards precision use for prevention and treatment of colorectal cancer

Fatty acid desaturase insertion-deletion polymorphism rs66698963 predicts colorectal polyp prevention by the n-3 fatty acid eicosapentaenoic acid: a secondary analysis of the seAFOod polyp prevention trial

BACKGROUND

A fatty acid desaturase (FADS) insertion-deletion (Indel) polymorphism (rs66698963) influences the expression of FADS1, which controls the synthesis of n-6 highly unsaturated fatty acid (HUFA) arachidonic acid (AA). The anti-inflammatory activity of the n-3 HUFA eicosapentaenoic acid (EPA) may be explained by competition with AA for proinflammatory lipid mediator synthesis. A precision medicine approach based on stratification by FADS Indel genotype could identify individuals, who benefit from greatest disease risk reduction by n-3 HUFAs.

OBJECTIVES

We tested the hypothesis that the FADS insertion (I) allele predicts colorectal polyp risk reduction in a secondary analysis of the randomized, placebo-controlled, 2×2 factorial seAFOod polyp prevention trial of EPA 2000 mg daily and aspirin 300 mg daily for 12 mo (ISRCTN05926847).

METHODS

Participant Indel genotype was determined by polymerase chain reaction (PCR) blind to trial outcomes. Colorectal polyp outcomes were included in negative binomial (polyp number) and logistic (polyp detection rate [PDR; percentage with one or more polyps]) regression models comparing each active intervention with its placebo. Presence of ≥1 Indel I allele and an interaction term (I allele × active intervention) were covariates.

RESULTS

In 528 participants with colonoscopy and FADS Indel data, EPA use irrespective of Indel genotype, was not associated with reduced colorectal polyp number (incidence rate ratio [IRR]: 0.92; 95% confidence interval: 0.74, 1.16), mirroring original seAFOod trial analysis. However, the presence of ≥1 I allele identified EPA users with a significant reduction in colorectal polyp number (IRR: 0.50 [0.28, 0.90]), unlike aspirin, for which there was no interaction. Similar findings were obtained for the PDR.

CONCLUSIONS

The FADS Indel I allele identified individuals, who displayed colorectal polyp prevention by EPA with a similar effect size to aspirin. Assessment of rs66698963 as a biomarker of therapeutic response to n-3 HUFAs in other populations and healthcare settings is warranted. The seAFOod polyp prevention trial and STOP-ADENOMA study were registered at International Standard Randomised Controlled Trial Number registry as ISRCTN05926847.

Research Advances of Lipid Nanoparticles in the Treatment of Colorectal Cancer

Colorectal cancer (CRC) is a common type of gastrointestinal tract (GIT) cancer and poses an enormous threat to human health. Current strategies for metastatic colorectal cancer (mCRC) therapy primarily focus on chemotherapy, targeted therapy, immunotherapy, and radiotherapy; however, their adverse reactions and drug resistance limit their clinical application. Advances in nanotechnology have rendered lipid nanoparticles (LNPs) a promising nanomaterial-based drug delivery system for CRC therapy. LNPs can adapt to the biological characteristics of CRC by modifying their formulation, enabling the selective delivery of drugs to cancer tissues. They overcome the limitations of traditional therapies, such as poor water solubility, nonspecific biodistribution, and limited bioavailability. Herein, we review the composition and targeting strategies of LNPs for CRC therapy. Subsequently, the applications of these nanoparticles in CRC treatment including drug delivery, thermal therapy, and nucleic acid-based gene therapy are summarized with examples provided. The last section provides a glimpse into the advantages, current limitations, and prospects of LNPs in the treatment of CRC.

The ω-3 Polyunsaturated Fatty Acid Docosahexaenoic Acid Enhances NK-Cell Antitumor Effector Functions

ω-3 polyunsaturated fatty acids (PUFA) are known to directly repress tumor development and progression. In this study, we explored whether docosahexaenoic acid (DHA), a type of ω-3 PUFA, had an immunomodulatory role in inhibiting tumor growth in immunocompetent mice. The number of natural killer (NK) cells but not the number of T or B cells was decreased by DHA supplementation in various tissues under physiologic conditions. Although the frequency and number of NK cells were comparable, IFNγ production by NK cells in both the spleen and lung was increased in DHA-supplemented mice in the mouse B16F10 melanoma tumor model. Single-cell RNA sequencing revealed that DHA promoted effector function and oxidative phosphorylation in NK cells but had no obvious effects on other immune cells. Using Rag2-/- mice and NK-cell depletion by PK136 antibody injection, we demonstrated that the suppression of B16F10 melanoma tumor growth in the lung by DHA supplementation was dependent mainly on NK cells. In vitro experiments showed that DHA directly enhanced IFNγ production, CD107a expression, and mitochondrial oxidative phosphorylation (OXPHOS) activity and slightly increased proliferator-activated receptor gamma coactivator-1α (PGC-1α) protein expression in NK cells. The PGC-1α inhibitor SR-18292 in vitro and NK cell-specific knockout of PGC-1α in mice reversed the antitumor effects of DHA. In summary, our findings broaden the current knowledge on how DHA supplementation protects against cancer growth from the perspective of immunomodulation by upregulating PGC-1α signaling-mediated mitochondrial OXPHOS activity in NK cells.

Fish oil supplement use modifies the relationship between dietary oily fish intake and plasma n-3 PUFA levels: an analysis of the UK Biobank

Observational evidence linking dietary n-3 PUFA intake and health outcomes is limited by a lack of robust validation of dietary intake using blood n-3 PUFA levels and potential confounding by fish oil supplement (FOS) use. We investigated the relationship between oily fish intake, FOS use and plasma n-3 PUFA levels in 121 650 UK Biobank (UKBB) participants. Ordinal logistic regression models, adjusted for clinical and lifestyle factors, were used to quantify the contribution of dietary oily fish intake and FOS use to plasma n-3 PUFA levels (measured by NMR spectroscopy). Oily fish intake and FOS use were reported by 38 % and 31 % of participants, respectively. Increasing oily fish intake was associated with a higher likelihood of FOS use (P < 0·001). Oily fish intake ≥ twice a week was the strongest predictor of high total n-3 PUFA (OR 6·7 (95 % CI 6·3, 7·1)) and DHA levels (6·6 (6·3, 7·1). FOS use was an independent predictor of high plasma n-3 PUFA levels (2·0 (2·0, 2·1)) with a similar OR to that associated with eating oily fish < once a week (1·9 (1·8, 2·0)). FOS use was associated with plasma n-3 PUFA levels that were similar to individuals in the next highest oily fish intake category. In conclusion, FOS use is more common in frequent fish consumers and modifies the relationship between oily fish intake and plasma n-3 PUFA levels in UKBB participants. If unaccounted for, FOS use may confound the relationship between dietary n-3 PUFA intake, blood levels of n-3 PUFAs and health outcomes.

Steady-State Delivery and Chemical Modification of Food Nutrients to Improve Cancer Intervention Ability

Cancer is a crucial global health problem, and prevention is an important strategy to reduce the burden of the disease. Daily diet is the key modifiable risk factor for cancer, and an increasing body of evidence suggests that specific nutrients in foods may have a preventive effect against cancer. This review summarizes the current evidence on the role of nutrients from foods in cancer intervention. It discusses the potential mechanisms of action of various dietary components, including phytochemicals, vitamins, minerals, and fiber. The findings of epidemiological and clinical studies on their association with cancer risk are highlighted. The foods are rich in bioactive compounds such as carotenoids, flavonoids, and ω-3 fatty acids, which have been proven to have anticancer properties. The effects of steady-state delivery and chemical modification of these food's bioactive components on anticancer and intervention are summarized. Future research should focus on identifying the specific bioactive compounds in foods responsible for their intervention effects and exploring the potential synergistic effects of combining different nutrients in foods. Dietary interventions that incorporate multiple nutrients and whole foods may hold promise for reducing the risk of cancer and improving overall health.

The arachidonic acid metabolome reveals elevation of prostaglandin E2 biosynthesis in colorectal cancer

Arachidonic acid metabolites are a family of bioactive lipids derived from membrane phospholipids. They are involved in cancer progression, but arachidonic acid metabolite profiles and their related biosynthetic pathways remain uncertain in colorectal cancer (CRC). To compare the arachidonic acid metabolite profiles between CRC patients and healthy controls, quantification was performed using a liquid chromatography-mass spectrometry-based analysis of serum and tissue samples. Metabolomics analysis delineated the distinct oxidized lipids in CRC patients and healthy controls. Prostaglandin (PGE2)-derived metabolites were increased, suggesting that the PGE2 biosynthetic pathway was upregulated in CRC. The qRT-PCR and immunohistochemistry analyses showed that the expression level of PGE2 synthases, the key protein of PGE2 biosynthesis, was upregulated in CRC and positively correlated with the CD68+ macrophage density and CRC development. Our study indicates that the PGE2 biosynthetic pathway is associated with macrophage infiltration and progression of CRC tumors.

Multi-omics analysis of the gut microbiome and metabolites associated with the psychoneurological symptom cluster in children with cancer receiving chemotherapy

BACKGROUND

Children with cancer receiving chemotherapy commonly report a cluster of psychoneurological symptoms (PNS), including pain, fatigue, anxiety, depression, and cognitive dysfunction. The role of the gut microbiome and its functional metabolites in PNS is rarely studied among children with cancer. This study investigated the associations between the gut microbiome-metabolome pathways and PNS in children with cancer across chemotherapy as compared to healthy children.

METHODS

A case-control study was conducted. Cancer cases were recruited from Children's Healthcare of Atlanta and healthy controls were recruited via flyers. Participants reported PNS using the Pediatric Patient-Reported Outcomes Measurement Information System. Data for cases were collected pre-cycle two chemotherapy (T0) and post-chemotherapy (T1), whereas data for healthy controls were collected once. Gut microbiome and its metabolites were measured using fecal specimens. Gut microbiome profiling was performed using 16S rRNA V4 sequencing, and metabolome was performed using an untargeted liquid chromatography-mass spectrometry approach. A multi-omics network integration program analyzed microbiome-metabolome pathways of PNS.

RESULTS

Cases (n = 21) and controls (n = 14) had mean ages of 13.2 and 13.1 years. For cases at T0, PNS were significantly associated with microbial genera (e.g., Ruminococcus, Megasphaera, and Prevotella), which were linked with carnitine shuttle (p = 0.0003), fatty acid metabolism (p = 0.001) and activation (p = 0.001), and tryptophan metabolism (p = 0.008). Megasphaera, clustered with aspartate and asparagine metabolism (p = 0.034), carnitine shuttle (p = 0.002), and tryptophan (p = 0.019), was associated with PNS for cases at T1. Gut bacteria with potential probiotic functions, along with fatty acid metabolism, tryptophan, and carnitine shuttle, were more clustered in cancer cases than the control network and this linkage with PNS needs further studies.

CONCLUSIONS

Using multi-omics approaches, this study indicated specific microbiome-metabolome pathways linked with PNS in children with cancer across chemotherapy. Due to limitations such as antibiotic use in cancer cases, these findings need to be further confirmed in a larger cohort.

Cancer patients' behaviors and attitudes toward natural health products

BACKGROUND

Natural health products (NHPs), including vitamins, minerals, and herbal supplements, are the most common complementary and alternative medicine (CAM) among cancer patients. Our survey determined the attitudes and behaviors of cancer patients toward natural complementary therapies that should be considered to implement an integrative approach in the future.

METHODS

Our survey was conducted in four hospitals in Belgium. Questionnaires were posted online from October 2020 to October 2021 for cancer patients. Descriptive statistics were used to analyze the data. A [Formula: see text] test was applied to study the type of NHP consumed according to diagnosis time. Fischer's exact test compared patients who had changed their consumption since diagnosis and those who had not.

RESULTS

Out of 349 questionnaires collected, only 59 met all inclusion criteria. 83.1 % of the patients agreed that conventional medicine (CM) could benefit from complementary therapies, but they did not estimate (72.3 % of the patients) that those latter are more effective than conventional medicine. More than half of the patients used five or more NHPs. The most frequent NHPs consumed daily were vitamins (64.4 %), followed by other products (i.e., probiotics, gemmotherapy, birch sap and omega 3/6) (42.4 %) and herbs (40.7 %). Almost all patients started taking NHPs before their cancer diagnosis, but 72.7 % have changed their consumption significantly (p = 0.009) since their diagnosis. Boosting the immune system (79.7 %) and limiting conventional treatment side effects (76.9 %) were the most common reasons for NHPs' use. 74.4 % of the patients did not take complementary therapies to delay or avoid conventional treatment.

CONCLUSIONS

The combination and high diversity of NHPs consumption highlight the importance of educating patients and healthcare providers (HCPs) about the risk of drug interactions associated with these natural products. Most cancer patients are more interested in using this non-mainstream medicine to complement their conventional treatment than as an alternative. Knowing the patients' reasons and understanding patients' attitudes toward NHPs will be essential for HCPs to address NHPs' use.

Randomised, placebo-controlled, phase 3 trial of the effect of the omega-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA) on colorectal cancer recurrence and survival after surgery for resectable liver metastases: EPA for Metastasis Trial 2 (EMT2) study protocol

INTRODUCTION

There remains an unmet need for safe and cost-effective adjunctive treatment of advanced colorectal cancer (CRC). The omega-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA) is safe, well-tolerated and has anti-inflammatory as well as antineoplastic properties. A phase 2 randomised trial of preoperative EPA free fatty acid 2 g daily in patients undergoing surgery for CRC liver metastasis showed no difference in the primary endpoint (histological tumour proliferation index) compared with placebo. However, the trial demonstrated possible benefit for the prespecified exploratory endpoint of postoperative disease-free survival. Therefore, we tested the hypothesis that EPA treatment, started before liver resection surgery (and continued postoperatively), improves CRC outcomes in patients with CRC liver metastasis.

METHODS AND ANALYSIS

The EPA for Metastasis Trial 2 trial is a randomised, double-blind, placebo-controlled, phase 3 trial of 4 g EPA ethyl ester (icosapent ethyl (IPE; Vascepa)) daily in patients undergoing liver resection surgery for CRC liver metastasis with curative intent. Trial treatment continues for a minimum of 2 years and maximum of 4 years, with 6 monthly assessments, including quality of life outcomes, as well as annual clinical record review after the trial intervention. The primary endpoint is CRC progression-free survival. Key secondary endpoints are overall survival, as well as the safety and tolerability of IPE. A minimum 388 participants are estimated to provide 247 CRC progression events during minimum 2-year follow-up, allowing detection of an HR of 0.7 in favour of IPE, with a power of 80% at the 5% (two sided) level of significance, assuming drop-out of 15%.

ETHICS AND DISSEMINATION

Ethical and health research authority approval was obtained in January 2018. All data will be collected by 2025. Full trial results will be published in 2026. Secondary analyses of health economic data, biomarker studies and other translational work will be published subsequently.

TRIAL REGISTRATION NUMBER

NCT03428477.

Polymorphisms in Cyclooxygenase, Lipoxygenase, and TP53 Genes Predict Colorectal Polyp Risk Reduction by Aspirin in the seAFOod Polyp Prevention Trial

Aspirin and eicosapentaenoic acid (EPA) reduce colorectal adenomatous polyp risk and affect synthesis of oxylipins including prostaglandin E2. We investigated whether 35 SNPs in oxylipin metabolism genes such as cyclooxygenase (PTGS) and lipoxygenase (ALOX), as well as 7 SNPs already associated with colorectal cancer risk reduction by aspirin (e.g., TP53; rs104522), modified the effects of aspirin and EPA on colorectal polyp recurrence in the randomized 2 × 2 factorial seAFOod trial. Treatment effects were reported as the incidence rate ratio (IRR) and 95% confidence interval (CI) by stratifying negative binomial and Poisson regression analyses of colorectal polyp risk on SNP genotype. Statistical significance was reported with adjustment for the false discovery rate as the P and q value. 542 (of 707) trial participants had both genotype and colonoscopy outcome data. Reduction in colorectal polyp risk in aspirin users compared with nonaspirin users was restricted to rs4837960 (PTGS1) common homozygotes [IRR, 0.69; 95% confidence interval (CI), 0.53-0.90); q = 0.06], rs2745557 (PTGS2) compound heterozygote-rare homozygotes [IRR, 0.60 (0.41-0.88); q = 0.06], rs7090328 (ALOX5) rare homozygotes [IRR 0.27 (0.11-0.64); q = 0.05], rs2073438 (ALOX12) common homozygotes [IRR, 0.57 (0.41-0.80); q = 0.05], and rs104522 (TP53) rare homozygotes [IRR, 0.37 (0.17-0.79); q = 0.06]. No modification of colorectal polyp risk in EPA users was observed. In conclusion, genetic variants relevant to the proposed mechanism of action on oxylipins are associated with differential colorectal polyp risk reduction by aspirin in individuals who develop multiple colorectal polyps. SNP genotypes should be considered during development of personalized, predictive models of colorectal cancer chemoprevention by aspirin.

PREVENTION RELEVANCE

Single-nucleotide polymorphisms in genes controlling lipid mediator signaling may modify the colorectal polyp prevention activity of aspirin. Further investigation is required to determine whether testing for genetic variants can be used to target cancer chemoprevention by aspirin to those who will benefit most.

The Active Fraction of Polyrhachis vicina Roger (AFPR) activates ERK to cause necroptosis in colorectal cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Polyrhachis vicina Roger (P. vicina), a traditional Chinese medicinal animal, has been used to treat rheumatoid arthritis, hepatitis, cancer, and other conditions. Due to its anti-inflammatory properties, our previous pharmacological investigations have demonstrated that it is effective against cancer, depression, and hyperuricemia. Nevertheless, the key active components and targets of P. vicina in cancers are still unexplored.

AIM OF THE STUDY

The study aimed to evaluate the pharmacological treatment mechanism of the active fraction of P. vicina (AFPR) in treating colorectal cancer (CRC) and to further reveal its active ingredients and key targets.

METHODS

To examine the inhibitory impact of AFPR on CRC growth, tumorigenesis assays, cck-8 assays, colony formation assays, and MMP detection were utilized. The primary components of AFPR were identified by GC-MS analysis. The network pharmacology, molecular docking, qRT-PCR, western blotting, CCK-8 assays, colony formation assay, Hoechst staining, Annexin V-FITC/PI double staining, and MMP detection were performed to pick out the active ingredients and potential key targets of AFPR. The function of Elaidic acid on necroptosis was investigated through siRNA interference and the utilization of inhibitors. Elaidic acid's effectiveness to suppress CRC growth in vivo was assessed using a tumorigenesis experiment.

RESULTS

Studies confirmed that AFPR prevented CRC from growing and evoked cell death. Elaidic acid was the main bioactive ingredient in AFPR that targeted ERK. Elaidic acid greatly affected the ability of SW116 cells to form colonies, produce MMP, and undergo necroptosis. Additionally, Elaidic acid promoted necroptosis predominantly by activating ERK/RIPK1/RIPK3/MLKL.

CONCLUSION

According to our findings, Elaidic acid is the main active component of AFPR, which induced necroptosis in CRC through the activation of ERK. It represents a promising alternative therapeutic option for CRC. This work provided experimental support for the therapeutic application of P. vicina Roger in the treatment of CRC.

Body mass index-based predictions and personalized clinical strategies for colorectal cancer in the context of PPPM

Currently colorectal cancer (CRC) is the third most prevalent cancer worldwide. Body mass index (BMI) is frequently used in CRC screening and risk assessment to quantitatively evaluate weight. However, the impact of BMI on clinical strategies for CRC has received little attention. Within the framework of the predictive, preventive, and personalized medicine (3PM/PPPM), we hypothesized that BMI stratification would affect the primary, secondary, and tertiary care options for CRC and we conducted a critical evidence-based review. BMI dynamically influences CRC outcomes, which helps avoiding adverse treatment effects. The outcome of surgical and radiation treatment is adversely affected by overweight (BMI ≥ 30) or underweight (BMI < 20). A number of interventions, such as enhanced recovery after surgery and robotic surgery, can be applied to CRC at all levels of BMI. BMI-controlling modalities such as exercise, diet control, nutritional therapy, and medications may be potentially beneficial for patients with CRC. Patients with overweight are advised to lose weight through diet, medication, and physical activity while patients suffering of underweight require more focus on nutrition. BMI assists patients with CRC in better managing their weight, which decreases the incidence of adverse prognostic events during treatment. BMI is accessible, noninvasive, and highly predictive of clinical outcomes in CRC. The cost-benefit of the PPPM paradigm in developing countries can be advanced, and the clinical benefit for patients can be improved with the promotion of BMI-based clinical strategy models for CRC.

Fatty Acid Composition and Cytotoxic Activity of Lipid Extracts from Nannochloropsis gaditana Produced by Green Technologies

Microalgae are alternatives and sustainable sources of omega-3 long chain-polyunsaturated fatty acids (LC-PUFA). However, the eco-friendly extraction of these bioactives remains unexplored. In this work, the use of enzyme-based methods in combination with ultrasounds was evaluated as green approaches to extract the omega-3 lipids from Nannochloropsis gaditana. Three commercial enzymatic solutions (Viscozyme® L, Celluclast® 1.5 L, and Saczyme®) were investigated, and results were compared with the traditional Folch method. A promising extraction approach was developed by using Saczyme®, achieving a lipid yield of 25.7% ± 0.5, comparable to the traditional method (27.3% ± 0.7) (p > 0.05). Similar omega-3 content was found by GC−MS analysis for both lipid extracts (30.2% ± 2.4 and 29.3% ± 0.8 for the green and the traditional method, respectively), showing that the green approaches did not affect the fatty acid profile. Moreover, the cytotoxic activity of produced lipids was assessed by comparing human colon cancer cells (HCT-116) and epithelial nontumorigenic immortalized cells (HCEC-1CT). Results suggest that the lipid extracts have a selective effect, reducing the viability of the colon carcinoma cells but not the nontumorigenic cells. Thus, this study provides new eco-innovative approaches for extracting the omega-3 LC-PUFA from microalgae with promising biological properties.