Dietary omega-3-polyunsaturated fatty acids prevent the development of metastases of colon carcinoma in rat liver

Fish Consumption and Colorectal Cancer Risk: Meta-Analysis of Prospective Epidemiological Studies and Review of Evidence from Animal Studies

Background: Epidemiological studies on the association between fish consumption and colorectal cancer (CRC) risk have yielded inconsistent results, despite evidence from preclinical studies that long-chain ω-3 polyunsaturated fatty acids inhibit colorectal carcinogenesis. We conducted a meta-analysis of prospective epidemiological studies investigating the association between fish consumption and CRC risk among humans and reviewed studies examining the link between fish components and colorectal carcinogenesis in animal models. Methods: We included studies published until November 2020. We calculated the summary risk ratio (SRR) and 95% confidence intervals (CI) through random effects meta-analysis models in order to summarize evidence from studies among humans. Results: Twenty-five prospective epidemiological studies encompassing 25,777 CRC cases were included. Individuals in the highest (vs. lowest) category of fish consumption had a significantly reduced risk of CRC (SRR 0.94, 95%CI 0.89-0.99). In dose-response meta-analysis, a 50-g increment in the daily consumption of fish was associated with a statistically significant 4% reduction in CRC risk (SRR 0.96, 95%CI 0.92-0.99). Preclinical studies (n = 25) identified multiple mechanisms of action of fish and fish components on colorectal carcinogenesis. Conclusions: Dietary recommendations for cancer prevention should take into account the evidence from epidemiological and preclinical studies that increasing fish consumption may be effective in preventing CRC.

Free Fatty Acid Receptors as New Potential Targets in Colorectal Cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide. In developed countries, its mortality remains high, yet the prevalence has established owing to effective screening programs; however due to the westernization of lifestyle, the incidences in many other countries have increased. Although the treatment of CRC has improved in the last few years, the side effects of these approaches cannot be neglected. Recently, members of the family of free fatty acid receptors (FFARs) have become attractive pharmacological targets in many diseases, including asthma; studies also point to their role in carcinogenesis. Here, we discuss current knowledge and future directions in FFAR research related to CRC. Contradictory results of FFARs modulation may derive from the pleiotropic effects of FFAR ligands, receptor distribution and different signal transduction. Hence, we indicate directions of further studies to fully use the potential of FFARs in CRC.

N-3 Polyunsaturated fatty acid ethyl esters decrease the invasion, but not the proliferation, of human colorectal cancer cells via a PI3K-dependent mechanism in vitro

N-3 polyunsaturated fatty acid (PUFA) ethyl esters have been approved by the FDA for the treatment of dyslipidemia and are promising cancer therapeutics. The study objectives were to determine if and how n-3 PUFA ethyl esters affected the proliferation and invasion of colorectal cancer cells. SW620 and HCT-116 parental and HCT-116 mutant cells isogenic for constitutively active PI3K were treated with free or ethyl esterified n-3 PUFAs and counted 72 h later. Cells were also administered n-3 PUFA ethyl esters to determine if these compounds decreased invasion through Boyden chambers and PI3K activity via western blot analysis of phosphorylated Akt. Free and n-3 PUFA ethyl esters decreased the proliferation of all cell lines. The invasion and Akt phosphorylation of both parental cell lines was decreased following treatment but this did not occur in mutant cells. The ability of n-3 PUFA ethyl esters to decrease proliferation and invasion in vitro indicates these compounds may be effective in vivo.

Zinc, ω-3 polyunsaturated fatty acids and vitamin D: An essential combination for prevention and treatment of cancers

Zinc, ω-3 polyunsaturated fatty acids (PUFAs) and vitamin D are essential nutrients for health, maturation and general wellbeing. Extensive literature searches have revealed the widespread similarity in molecular biological properties of zinc, ω-3 PUFAs and vitamin D, and their similar anti-cancer properties, even though they have different modes of action. These three nutrients are separately essential for good health, especially in the aged. Zinc, ω-3 PUFAs and vitamin D are inexpensive and safe as they are fundamentally natural and have the properties of correcting and inhibiting undesirable actions without disturbing the normal functions of cells or their extracellular environment. This review of the anticancer properties of zinc, ω-3 PUFAs and vitamin D is made in the context of the hallmarks of cancer. The anticancer properties of zinc, ω-3 PUFAs and vitamin D can therefore be used beneficially through combined treatment or supplementation. It is proposed that sufficiency of zinc, ω-3 PUFAs and vitamin D is a necessary requirement during chemotherapy treatment and that clinical trials can have questionable integrity if this sufficiency is not checked and maintained during efficacy trials.

ω-3 Polyunsaturated Fatty Acids on Colonic Inflammation and Colon Cancer: Roles of Lipid-Metabolizing Enzymes Involved

Substantial human and animal studies support the beneficial effects of ω-3 polyunsaturated fatty acids (PUFAs) on colonic inflammation and colorectal cancer (CRC). However, there are inconsistent results, which have shown that ω-3 PUFAs have no effect or even detrimental effects, making it difficult to effectively implement ω-3 PUFAs for disease prevention. A better understanding of the molecular mechanisms for the anti-inflammatory and anticancer effects of ω-3 PUFAs will help to clarify their potential health-promoting effects, provide a scientific base for cautions for their use, and establish dietary recommendations. In this review, we summarize recent studies of ω-3 PUFAs on colonic inflammation and CRC and discuss the potential roles of ω-3 PUFA-metabolizing enzymes, notably the cytochrome P450 monooxygenases, in mediating the actions of ω-3 PUFAs.

Omega-3 fatty acids in pathological calcification and bone health

Omega-3 fatty acids (ω-3FAs) such as Docosahexaenoic acid (DHA) and Eicosapentanoic acid (EPA), are active ingredient of fish oil, which have larger health benefits against various diseases including cardiovascular, neurodegenerative, cancers and bone diseases. Substantial studies documented a preventive role of omega-3 fatty acids in pathological calcification like vascular calcification and microcalcification in cancer tissues. In parallel, these fatty acids improve bone quality probably by preventing bone decay and augmenting bone mineralization. This study also addresses that the functions of ω-3FAs not only depend on tissue types, but also work through different molecular mechanisms for preventing pathological calcification in various tissues and improving bone health. PRACTICAL APPLICATIONS: Practical applications of the current study are to improve the knowledge about the supplementation of omega-3 fatty acids. This study infers that supplementation of omega-3 fatty acids aids in bone preservation in elder females at the risk of osteoporosis and also, on the contrary, omega-3 fatty acids interfere with pathological calcification of vascular cells and cancer cells. Omega-3 supplementation should be given to the cardiac patients because of its cardio protective role. In line with this, omega-3 supplementation should be included with chemotherapy for cancer patients as it can prevent osteoblastic potential of breast cancer patients, responsible for pathological mineralization, and blocks off target toxicities. Administration of omega-3 fatty acid with chemotherapy will not only improve survival of cancer patients, but also improve the bone quality. Thus, this study allows a better understanding on omega-3 fatty acids in combating pathological complications such as osteoporosis, vascular calcification, and breast microcalcification.

Fatty liver decreases the risk of liver metastasis in patients with breast cancer: a two-center cohort study

BACKGROUND

The influence of hepatic steatosis (HS) on liver metastasis in patients with non-metastatic breast cancer (BC) remains unclear. The aim of this study was to clarify the relationship between HS and liver metastasis in non-metastatic BC patients.

METHODS

Patients who underwent treatment for BC at two affiliated hospitals of Southern Medical University, between January 1, 2005 and December 31, 2015, were retrospectively reviewed. BC patients were divided into the study and control groups based on the presence of HS. The association between HS and liver metastasis was analyzed, adjusting for the confounding factors using Cox regression and propensity score case-match analysis.

RESULTS

In total, 1230 female BC patients were included, and 372 (30.2%) patients were diagnosed with HS (at the time of diagnosis BC or before). The cumulative liver metastasis-free survival (MFS) rate was significantly higher in the study group than in the control group (hazard ratio 0.61; 95% confidence interval 0.40-0.94; P = 0.024). On multivariate analysis, HS was an independent protective factor for local liver metastasis (HR 0.55; 0.35-0.86; P = 0.008). After one-to-one matching of the study group (344) with the control group (344), liver MFS remained significantly better in the study group (HR 0.42; 0.26-0.69; P = 0.001).

CONCLUSION

This study indicated that HS may serve as an independent factor to decrease liver metastasis in patients with BC. Additional prospective studies are necessary to validate this finding.

Polyunsaturated Fatty Acids and Their Derivatives: Therapeutic Value for Inflammatory, Functional Gastrointestinal Disorders, and Colorectal Cancer

Polyunsaturated fatty acids (PUFAs) are bioactive lipids which modulate inflammation and immunity. They gained recognition in nutritional therapy and are recommended dietary supplements. There is a growing body of evidence suggesting the usefulness of PUFAs in active therapy of various gastrointestinal (GI) diseases. In this review we briefly cover the systematics of PUFAs and their metabolites, and elaborate on their possible use in inflammatory bowel disease (IBD), functional gastrointestinal disorders (FGIDs) with focus on irritable bowel syndrome (IBS), and colorectal cancer (CRC). Each section describes the latest findings from in vitro and in vivo studies, with reports of clinical interventions when available.

Role of β-catenin signaling in the anti-invasive effect of the omega-3 fatty acid DHA in human melanoma cells

BACKGROUND

We previously found that docosahexaenoic acid (DHA), a dietary polyunsaturated fatty acid present at high level in fatty fish, inhibited cell growth and induced differentiation of melanoma cells in vitro by increasing nuclear β-catenin content. An anti-neoplastic role of nuclear β-catenin was suggested in melanoma, and related to the presence in the melanocyte lineage of the microphtalmia transcription factor (MITF), which interferes with the transcription of β-catenin/TCF/LEF pro-invasive target genes.

OBJECTIVE

In the present work we investigated if DHA could inhibit the invasive potential of melanoma cells, and if this effect could be related to DHA-induced alterations of the Wnt/β-catenin signaling, including changes in MITF expression.

METHODS

WM115 and WM266-4 human melanoma, and B16-F10 murine melanoma cell lines were used. Cell invasion was evaluated by Wound Healing and Matrigel transwell assays. Protein expression was analyzed by Western Blotting and β-catenin phosphorylation by immunoprecipitation. The role of MITF in the anti-invasive effect of DHA was analyzed by siRNA gene silencing.

RESULTS

We found that DHA inhibited anchorage-independent cell growth, reduced their migration/invasion in vitro and down-regulated several Matrix Metalloproteinases (MMP: MMP-2, MT1-MMP and MMP-13), known to be involved in melanoma invasion. We related these effects to the β-catenin increased nuclear expression and PKA-dependent phosphorylation, as well as to the increased expression of MITF.

CONCLUSION

The data obtained further support the potential role of dietary DHA as suppressor of melanoma progression to invasive malignancy through its ability to enhance MITF expression and PKA-dependent nuclear β-catenin phosphorylation.

Obesity and colorectal liver metastases: Mechanisms and management

INTRODUCTION

Colorectal cancer (CRC) is the third commonest malignancy after lung and breast cancer. The most common cause of mortality from CRC is from distant metastases. Obesity is a known risk factor for primary CRC development. However, its role in metastatic disease progression is not fully understood. The article aims to provide an overview of the role of obesity in colorectal liver metastases (CRLM). Furthermore, possible strategies to minimise this effect are discussed. An electronic search of MedLine, EMBASE, CINAHL and google scholar was performed. Relevant articles were included in the article. Obesity causes localised inflammation within the liver microenvironment which may predispose to metastases development. Furthermore, obesity causes systemic inflammation leading to release of protumourigenic growth factors. Several studies demonstrated the effects of lifestyle modification, medications, bariatric surgery and omega-3 fatty acids on steatosis within the context of liver surgery. It is currently unclear whether obesity directly leads to metastatic disease via chronic systemic inflammation or whether obesity induced steatosis provides a fertile microenvironment for metastases deposition. With a global increase in obesity useful strategies to minimise the effects of obesity on the liver include life-style modification, pre-operative dietary regimes and omega-3 fatty acids intake. Pre-operative optimisation of the patient is a key concept. Further randomised control trials are needed to guide management strategies.

Potential applications of fish oils rich in omega-3 polyunsaturated fatty acids in the management of gastrointestinal cancer

BACKGROUND & AIMS

Despite advances in chemotherapeutic agents and surgical approaches for its management, gastrointestinal cancer still accounts for 27% of new cancer cases and 35% of cancer related mortality worldwide. Omega-3 polyunsaturated fatty acids (PUFAs) specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have anti-inflammatory and anticancer activities and are used as immuno-nutrients.

METHODS

A literature search was conducted to identify primary research reporting on applications of the omega-3 PUFAs in gastrointestinal cancer.

RESULTS

Reported laboratory studies indicate a clear role for omega-3 PUFAs in preventing cancer development at various stages including cancer cell proliferation, survival, angiogenesis, inflammation and metastasis. In clinical settings, omega-3 PUFAs have been reported to improve the immune response, maintain lean body mass, improve quality of life and improve overall survival in patients with colorectal and pancreatic cancer. In contrast to other GI cancers, there is a strong connection between inflammation and oesophageal cancer.

CONCLUSIONS

Little work has been done exploring the role for omega-3 PUFAs in oesophageal cancer prevention and management. The authors are conducting a clinical trial investigating the use of parenteral omega-3 PUFAs supplementary to the standard of care (epirubicin, oxaliplatin and capecitabine palliative chemotherapy) in patients with advanced oesophagogastric cancer as a promising new therapeutic approach.

Prevention of diabetes-promoted colorectal cancer by (n-3) polyunsaturated fatty acids and (n-3) PUFA mimetic

The global obesity / diabetes epidemic has resulted in robust increase in the incidence of colorectal cancer (CRC). Epidemiological, animal and human studies have indicated efficacy of (n-3) PUFA in chemoprevention of sporadic and genetic-driven CRC. However, diabetes-promoted CRC presents a treatment challenge that surpasses that of sporadic CRC. This report analyzes the efficacy of (n-3) PUFA generated by the fat-1 transgene that encodes an (n-6) to (n-3) PUFA desaturase, and of synthetic (n-3) PUFA mimetic (MEDICA analog), to suppress CRC development in carcinogen-induced diabetes-promoted animal model. Carcinogen-induced CRC is shown here to be promoted by the diabetes context, in terms of increased aberrant crypt foci (ACF) load, cell proliferation and epithelial dedifferentiation, being accompanied by increase in the expression of HNF4α, β-catenin, and β-catenin-responsive genes. Incorporating the fat-1 transgene in the diabetes context, or oral MEDICA treatment, resulted in ameliorating the diabetic phenotype and in abrogating CRC, with decrease in ACF load, cell proliferation and the expression of HNF-4α, β-catenin, and β-catenin-responsive genes. The specificity of (n-3) PUFA in abrogating CRC development, as contrasted with enhancing CRC by (n-6) PUFA, was similarly verified in CRC cell lines. These findings may indicate prospective therapeutic potential of (n-3) PUFA or MEDICA in the management of CRC, in particular diabetes-promoted CRC.

Docosahexaenoic acid promotes apoptosis and inhibits proliferation of HepG2 cells by altering β-catenin and C-myc expression

AIM: To investigate the effects of docosahexaenoic acid (DHA) of different concentrations on the proliferation and apoptosis of human hepatocelluar carcinoma HepG2 cells, and to explore the possible molecular mechanisms involved.

METHODS: HepG2 cells were cultured in vitro and treated with different concentrations of DHA (15, 30, 45, 60, 75 μg/mL) for different durations, with untreated cells as controls. The relative rate of reduced growth of HepG2 cells was detected by the CCK-8 method. Flow cytometry assay was applied to determine the rate of HepG2 cell apoptosis. After DHA treatment, the levels of β-catenin and C-myc mRNAs and proteins were measured by real-time PCR and Western blot, respectively.

RESULTS: In the concentration range from 0 to 45 mg/mL and with a treatment time of 24 h, DHA significantly inhibit the growth of HepG2 cells in vitro, and significant differences in the absorbance (A value) were observed between the experimental group and control group (P < 0.01), and between each two concentrations in the experimental group. If drug concentration or action time was increased, the results showed no statistically significant differences. Flow cytometric analysis indicated that DHA promotes the apoptosis of HepG2 cells. There were significant differences in the apoptosis rate between the experimental group and control group (P < 0.01), and between each two concentrations in the experimental group. Real-time PCR detected low levels of C-myc expression in HepG2 cells treated with DHA, and significant differences in C-myc expression were observed between the experimental group and control group (P < 0.01) and between each two concentrations in the experimental group. There was no significant difference in β-catenin relative expression between the experimental group and control group, or between different concentrations in the experimental group. Western blot analysis demonstrated that DHA could decrease the protein expression of β-catenin and C-myc in HepG2 cells.

CONCLUSION: DHA promotes apoptosis and inhibits proliferation of HepG2 cells possibly via mechanism associated with down-regulating the protein expression of β-catenin and the mRNA expression of C-myc.

Hepatic steatosis is associated with lower incidence of liver metastasis from colorectal cancer

PURPOSE

Both hepatic steatosis (HS) and colorectal cancer (CRC) are conditions associated with metabolic syndrome. The liver is the most frequent site of distant metastasis of CRC; however, the impact of HS on the incidence of liver metastasis of CRC is not clearly defined. Then, the correlation with the presence or absence of HS was analyzed.

METHODS

A total of 604 CRC patients receiving curative surgical resection who had a preoperative non-enhanced computed tomography (CT) were enrolled. The mean attenuation values (in Hounsfield units) of the liver and spleen were obtained on a plain CT slice, and the patients with liver-spleen attenuation ratio lower than 1.1 were objectively defined as HS. The clinicopathological features of these patients were analyzed, and the association between HS and the clinical features of CRC was examined.

RESULTS

Sixty-three (10.4%) among the 604 patients were diagnosed as HS. Recurrence-free survival (RFS) and hepatic RFS, but not extrahepatic RFS, were significantly higher in the group with HS (p = 0.04 and p = 0.006). However, this effect was not evident in the group of patients with obesity, defined as body mass index > 25.0. Among the stage I~III cases, HS was significantly associated with lower hepatic, but not extrahepatic, RFS. Moreover, absence of HS was an independent risk factor for hepatic RFS (p = 0.003).

CONCLUSION

Metastases of CRC are less frequent in fatty liver. Steatosis may be an unfavorable microenvironment for metastatic formation in the liver.

Regulating surgical oncotaxis to improve the outcomes in cancer patients

Excessive surgical stress and postoperative complications cause a storm of perioperative cytokine release, which has been shown to enhance tumor metastasis in experimental models. We have named this phenomenon "surgical oncotaxis". The mechanisms that underpin this process are thought to be excessive corticosteroid secretion, coagulopathy in the peripheral vasculature, immune suppression and excessive production of reactive oxygen species. Nuclear factor-kappa B (NFkB) activation plays a key role in these mechanisms. Minimally invasive surgical techniques should be used, and postoperative complications should be avoided whenever possible to lessen the impact of surgical oncotaxis. Furthermore, there may be a role for a small preoperative dose of corticosteroid or the use of free radical scavengers in the perioperative period. Recently, there has been a great deal of interest in omega-3 fatty acid, because it regulates NFkB activation. The use of multimodal treatments that regulate surgical oncotaxis may be as important as chemotherapy for determining the outcome of patients with cancer undergoing surgery.

Dietary ω -3 polyunsaturated fatty acid DHA: a potential adjuvant in the treatment of cancer

ω-3 Polyunsaturated fatty acids (PUFAs), mainly present in fish oil, are part of the human diet. Among PUFAs, docosahexaenoic acid (DHA) has received particular attention for its anti-inflammatory, antiproliferative, proapoptotic, antiangiogenetic, anti-invasion, and antimetastatic properties. These data suggest that DHA can exert antitumor activity potentially representing an effective adjuvant in cancer chemotherapy. This review is focused on current knowledge supporting the potential use of DHA for the enhancement of the efficacy of anticancer treatments in relation to its ability to enhance the uptake of anticancer drugs, regulate the oxidative status of tumor cells, and inhibit tumor cell invasion and metastasis.

The omega-3 polyunsaturated fatty acid eicosapentaenoic acid inhibits mouse MC-26 colorectal cancer cell liver metastasis via inhibition of PGE2-dependent cell motility

BACKGROUND AND PURPOSE

The omega-3 polyunsaturated fatty acid (PUFA) eicosapentaenoic acid (EPA) has antineoplastic activity at early stages of colorectal carcinogenesis, relevant to chemoprevention of colorectal cancer (CRC). We tested the hypothesis that EPA also has anti-CRC activity at later stages of colorectal carcinogenesis, relevant to treatment of metastatic CRC, via modulation of E-type PG synthesis.

EXPERIMENTAL APPROACH

A BALB/c mouse model, in which intrasplenic injection of syngeneic MC-26 mouse CRC cells leads to development of liver metastases, was used. Dietary EPA was administered in the free fatty acid (FFA) form for 2 weeks before and after ultrasound-guided intrasplenic injection of 1 × 10(6) MC-26 cells (n= 16 each group).

KEY RESULTS

Treatment with 5% (w w(-1)) EPA-FFA was associated with a reduced MC-26 mouse CRC cell liver tumour burden compared with control animals (median liver weight 1.03 g vs. 1.62 g; P < 0.034). Administration of 5% EPA-FFA was also linked to a significant increase in tumour EPA incorporation and lower intratumoural PGE(2) levels (with concomitant increased production of PGE(3)). Liver tumours from 5% EPA-FFA- treated mice demonstrated decreased 5-bromo-2-deoxyuridine-positive CRC cell proliferation and reduced phosphorylated ERK 1/2 expression at the invasive edge of tumours. A concentration-dependent reduction in MC-26 CRC cell Transwell® migration following EPA-FFA treatment (50-200 µM) in vitro was rescued by exogenous PGE(2) (10 µM) and PGE(1)-alcohol (1 µM).

CONCLUSIONS AND IMPLICATIONS

EPA-FFA inhibits MC-26 CRC cell liver metastasis. EPA incorporation is associated with a 'PGE(2) to PGE(3) switch' in liver tumours. Inhibition of PGE(2)-EP(4) receptor-dependent CRC cell motility probably contributes to the antineoplastic activity of EPA.

Effects of a ketogenic diet on the quality of life in 16 patients with advanced cancer: A pilot trial

BACKGROUND

Tumor patients exhibit an increased peripheral demand of fatty acids and protein. Contrarily, tumors utilize glucose as their main source of energy supply. Thus, a diet supplying the cancer patient with sufficient fat and protein for his demands while restricting the carbohydrates (CHO) tumors thrive on, could be a helpful strategy in improving the patients' situation. A ketogenic diet (KD) fulfills these requirements. Therefore, we performed a pilot study to investigate the feasibility of a KD and its influence on the quality of life of patients with advanced metastatic tumors.

METHODS

Sixteen patients with advanced metastatic tumors and no conventional therapeutic options participated in the study. The patients were instructed to follow a KD (less than 70 g CHO per day) with normal groceries and were provided with a supply of food additives to mix a protein/fat shake to simplify the 3-month intervention period. Quality of life [assessed by EORTC QLQ-C30 (version 2)], serum and general health parameters were determined at baseline, after every two weeks of follow-up, or after drop out. The effect of dietary change on metabolism was monitored daily by measuring urinary ketone bodies.

RESULTS

One patient did not tolerate the diet and dropped out within 3 days. Among those who tolerated the diet, two patients died early, one stopped after 2 weeks due to personal reasons, one felt unable to stick to the diet after 4 weeks, one stopped after 6 and two stopped after 7 and 8 weeks due to progress of the disease, one had to discontinue after 6 weeks to resume chemotherapy and five completed the 3 month intervention period. These five and the one who resumed chemotherapy after 6 weeks report an improved emotional functioning and less insomnia, while several other parameters of quality of life remained stable or worsened, reflecting their very advanced disease. Except for temporary constipation and fatigue, we found no severe adverse side effects, especially no changes in cholesterol or blood lipids.

CONCLUSIONS

These pilot data suggest that a KD is suitable for even advanced cancer patients. It has no severe side effects and might improve aspects of quality of life and blood parameters in some patients with advanced metastatic tumors.

Fish oil regulates cell proliferation, protect DNA damages and decrease HER-2/neu and c-Myc protein expression in rat mammary carcinogenesis

BACKGROUND & AIMS

The aim of this study is to assess the effect of dietary fish oil (MaxEPA) on DNA-strand breaks, cell proliferation and anti-apoptotic protein expressions in rat mammary carcinogenesis.

METHODS

Eighty-one female Sprague-Dawley rats were divided into two parts, one for DNA-strand breaks study and the other for immunohistochemical study. Female Sprague-Dawley rats were treated with 7,12-dimethylbenz(alpha)anthracene (DMBA) (0.5 mg/0.2 ml corn oil/100 g body weight) by a tail vein injection. Rats were fed either fish oil or corn oil (0.5 ml/day/rat) by oral gavage.

RESULTS

Fish oil-treated group showed significant protection against generation of single-strand breaks (SSBs) (56.1%, P < 0.05) but increased effect (72.3%, P < 0.05) was found in the corn oil-treated group when compared to DMBA control group. Furthermore, fish oil-treated group exhibited substantial decrease in Ki-67 (P < 0.05), HER-2/neu (P < 0.05) and c-Myc (P < 0.05) immunolabelling indices when compared to carcinogen counterpart. However, corn oil treatment resulted in significant increase in the above parameters.

CONCLUSIONS

The above data support the role of n-3 PUFA as a preventive agent for DNA damages and a potential to inhibit mammary carcinogenesis.

Dietary n-3 polyunsaturated fatty acids enhance metastatic dissemination of murine T lymphoma cells

Epidemiological investigation and animal studies have shown that dietary n-3 PUFA prevent the development and progression of certain types of cancer. However, conflicting results have been reported by the few studies that focused on the effect of dietary n-3 PUFA on the development of metastases. In the present study, we investigated the metastatic dissemination of murine T lymphoma lines with different metastatic potential transplanted into mice fed a fish oil diet, compared with mice fed a maize oil diet. Transplantation of highly metastatic S11 cells into animals fed a fish oil diet induced a large lymphomatoid infiltration in the spleen, associated with an eight-fold increase in spleen weight, compared with normal animals on the same diet. In contrast, only a limited increase in spleen weight was found in animals transplanted with S11 cells while fed a maize oil diet. No significant increase in spleen weight was found in animals transplanted with low-metastatic 164T2 cells regardless of whether they were fed a fish oil or a maize oil diet. At the end of experiment, an overt cachexia was shown by animals fed a fish oil diet transplanted with S11 cells, but not by those transplanted with 164T2 cells. The particularly high pro-metastatic effect of dietary n-3 PUFA on S11 cells rules out the generalisation that dietary n-3 PUFA inhibit tumour growth and progression.

Decreased polyunsaturated Fatty Acid content contributes to increased survival in human colon cancer

Among diet components, some fatty acids are known to affect several stages of colon carcinogenesis, whereas others are probably helpful in preventing tumors. In light of this, our aim was to determine the composition of fatty acids and the possible correlation with apoptosis in human colon carcinoma specimens at different Duke's stages and to evaluate the effect of enriching human colon cancer cell line with the possible reduced fatty acid(s). Specimens of carcinoma were compared with the corresponding non-neoplastic mucosa: a significant decrease of arachidonic acid, PPARα, Bad, and Bax and a significant increase of COX-2, Bcl-2, and pBad were found. The importance of arachidonic acid in apoptosis was demonstrated by enriching a Caco-2 cell line with this fatty acid. It induced apoptosis in a dose- and time-dependent manner via induction of PPARα that, in turn, decreased COX-2. In conclusion, the reduced content of arachidonic acid is likely related to carcinogenic process decreasing the susceptibility of cancer cells to apoptosis.

PROUD: effects of preoperative long-term immunonutrition in patients listed for liver transplantation

Background

Patients with end stage liver disease are characteristically malnourished which is associated with poor outcome. Formulas enriched with arginine, ω-3 fatty acids, and nucleotides, "immunonutrients", potentially improve their nutritional status. This study is designed to evaluate the clinical outcome of long-term "immunonutrition" of patients with end-stage liver disease while on the waiting list for liver transplantation.

Methods/design

A randomized controlled double blind multi-center clinical trial with two parallel groups comprising a total of 142 newly registered patients for primary liver transplantation has been designed to assess the safety and efficacy of the long-term administration of ORAL IMPACT^®, an "immunonutrient" formula, while waiting for a graft. Patients will be enrolled the day of registration on the waiting list for liver transplantation. Study ends on the day of transplantation. Primary endpoints include improved patients' nutritional and physiological status, as measured by mid-arm muscle area, triceps skin fold thickness, grip strength, and fatigue score, as well as patients' health related quality of life. Furthermore, patients will be followed for 12 postoperative weeks to evaluate anabolic recovery after transplantation as shown by reduced post-transplant mechanical ventilation, hospital stay, wound healing, infectious morbidities (pneumonia, intraabdominal abscess, sepsis, line sepsis, wound infection, and urinary tract infection), acute and chronic rejection, and mortality.

Discussion

Formulas enriched with arginine, ω-3 fatty acids, and nucleotides have been proven to be beneficial in reducing postoperative infectious complications and length of hospital stay among the patients undergoing elective gastrointestinal surgery. Possible mechanisms include downregulation of the inflammatory responses to surgery and immune modulation rather than a sole nutritional effect.

Trial registration

ClinicalTrials.gov NCT00495859