Long-chain omega-3 polyunsaturated fatty acids decrease mammary tumor growth, multiorgan metastasis and enhance survival

Is there sufficient evidence to support the health benefits of including donkey milk in the diet?

Donkey milk has attracted attention due to its distinctive nutritional composition and potential health advantages, particularly because of its whey protein content, which includes lysozyme, α-lactalbumin, lactoferrin, and β-lactoglobulin and vitamin C, among other components. These elements contribute to immunoregulatory, antimicrobial, antioxidant, and anti-inflammatory properties, positioning donkey milk as a possible therapeutic option. In addition, due to the low levels of caseins, the casein-to-whey protein ratio, and the β-lactoglobulin content in donkey milk, it presents an optimal alternative for infant formula for individuals with cow's milk allergies. Moreover, research into donkey milk's potential for cancer prevention, diabetes management, and as a treatment for various diseases is ongoing, thanks to its bioactive peptides and components. Nevertheless, challenges such as its low production yield and the not fully understood mechanisms behind its potential therapeutic role necessitate more thorough investigation. This review consolidates the existing knowledge on the therapeutic possibilities of donkey milk, emphasizing its importance for human health and the need for more detailed studies to confirm its health benefits.

Erythrocyte membrane n-3 PUFA are inversely associated with breast cancer risk among Chinese women

The relationship between erythrocyte membrane n-3 PUFA and breast cancer risk is controversial. We aimed to examine the associations of erythrocyte membrane n-3 PUFA with odds of breast cancer among Chinese women by using a relatively large sample size. A case-control study was conducted including 853 newly diagnosed, histologically confirmed breast cancer cases and 892 frequency-matched controls (5-year interval). Erythrocyte membrane n-3 PUFA were measured by GC. Logistic regression and restricted cubic spline were used to quantify the association between erythrocyte membrane n-3 PUFA and odds of breast cancer. Erythrocyte membrane α-linolenic acid (ALA), docosapentaenoic acid (DPA) and total n-3 PUFA were inversely and non-linearly associated with odds of breast cancer. The OR values (95 % CI), comparing the highest with the lowest quartile (Q), were 0·57 (0·43, 0·76), 0·43 (0·32, 0·58) and 0·36 (0·27, 0·49) for ALA, DPA and total n-3 PUFA, respectively. Erythrocyte membrane EPA and DHA were linearly and inversely associated with odds of breast cancer ((EPA: ORQ4 v. Q1 (95 % CI) = 0·59 (0·45, 0·79); DHA: ORQ4 v. Q1 (95 % CI) = 0·50 (0·37, 0·67)). The inverse associations were observed between ALA and odds of breast cancer in postmenopausal women, and between DHA and oestrogen receptor+ breast cancer. This study showed that erythrocyte membrane total and individual n-3 PUFA were inversely associated with odds of breast cancer. Other factors, such as menopause and hormone receptor status, may warrant further investigation when examining the association between n-3 PUFA and odds of breast cancer.

Evaluation of the Composition of the Cholesterol, Tocopherols, β-Carotene and Fatty Acids Profile of the Liver Tissue of Male Water Buffaloes (Bubalus bubalis) Managed in Different Ecosystems of the Eastern Amazon

The diet offered to animals has a great influence on the composition of tissues and, consequently, the quality. The objective of this study was to evaluate the influence of Amazonian ecosystems, in the dry and rainy periods of the year, on the composition of cholesterol, tocopherols, β-carotene and the fatty acid profile of the livers of water buffaloes (Bubalus bubalis) reared in the Eastern Amazon, in an extensive or intensive system. Total lipid content was influenced by the location and time of year (p < 0.05). Ninety-six male water buffaloes were used (12 per sampling period), aged between 24 and 36 months, with average weights of 432 kg (end of the rainy season) and 409 kg (end of the dry season). Total cholesterol, α-tocopherol and γ-tocopherol influenced the relationship between extensive vs intensive ecosystems, location, periods and the interaction between the location and period of the year (p < 0.05). Animals raised in a pasture ecosystem had the highest values of omega-3, and those raised in confinement, the highest values of omega-6 (p < 0.05). The proportions of n-6/n-3 and hypocholesterolemia (7.14) and hypercholesterolemia (3.08%) (h/H) were found in greater amounts in animals raised in confinement (p < 0.05). The atherogenic index (AI) had a higher value in the rainy season, in animals raised in Santarém (2.37%), with no difference between pasture and feedlot ecosystems, except in animals raised in the rainy season in Nova Timboteua, with a lower AI (1.53%). The thrombogenicity index (TI) was higher in the livers of confined animals (0.32%) and lower (0.18%) in those raised in Nova Timboteua (rainy season). Amazonian ecosystems influence the nutritional values of buffalo liver, with the best nutritional values in animals in the extensive system.

The Effects of Omega-3 Polyunsaturated Fatty Acids on Breast Cancer as a Preventive Measure or as an Adjunct to Conventional Treatments

In order to understand how omega-3 polyunsaturated fatty acid (ω-3 PUFA) supplements affect breast cancer prevention and treatment, a systematic review of articles published in the last 5 years in two databases was performed. Of the 679 articles identified, only 27 were included and examined based on five topics, taking into account: the induction type of the breast cancer used in animal models; the characteristics of the induction model by cell transplantation; the experimental design of the ω-3 supplementation—combined or not with a treatment antitumor drug; the fatty acids (FAs) composition used; the analysis of the studies’ outcomes. There are diverse and well-established animal models of breast cancer in the literature, with very relevant histological and molecular similarities depending on the specific objective of the study, such as whether the method of tumor induction was transgenic, by cell transplantation, or by oncogenic drugs. The analyses of outcomes were mainly focused on monitoring tumor growth, body/tumor weight, and molecular, genetic, or histological analyses, and few studies evaluated latency, survival, or metastases. The best results occurred when supplementation with ω-3 PUFA was associated with antitumor drugs, especially in the analysis of metastases and volume/weight of tumors or when the supplementation was started early and maintained for a long time. However, the beneficial effect of ω-3 PUFA supplementation when not associated with an antitumor agent remains unclear.

Effect of metabolism on the immune microenvironment of breast cancer

Breast cancer (BC) is a highly prevalent primary malignancy worldwide with poor prognosis. Despite the development of aggressive interventions, mortality due to BC remains high. BC cells reprogram nutrient metabolism to adapt to the energy acquisition and progression of the tumor. The metabolic changes in cancer cells are closely related to the abnormal function and effect of immune cells and immune factors, including chemokines, cytokines, and other related effector molecules in the tumor microenvironment (TME), leading to tumor immune escape, whereby the complex crosstalk between immune cells and cancer cells has been considered the key mechanism regulating cancer progression. In this review, we summarized the latest findings on metabolism-related processes in the immune microenvironment during BC progression. Our findings showing the impact of metabolism on the immune microenvironment may suggest new strategies for regulating the immune microenvironment and attenuating BC through metabolic interventions.

Effects of omega-3 polyunsaturated fatty acids on cellular development in human ovarian granulosa tumor cells (KGN)

Emerging research has shown that polyunsaturated fatty acids (PUFAs) benefit human health and exert anti-cancer effects. However, there is little understanding of the specific mechanisms by which PUFAs regulate the cells of the ovarian granulosa tumor. In the current study, we investigate the effects and the possible mechanisms of PUFAs on human ovarian tumor cells development. KGN cells were treated with omega-3. Small interfering (siRNA) and specific activator were used to knock down and overexpress gene expression in KGN cells. The protein content levels were analyzed by Western blot. Cell viability, proliferation and apoptosis assay were performed to examine the cellular development. And the level of glucose uptake in KGN cells were assessed by 2-DG measurement. The results showed that omega-3 treatment reduced cell viability, proliferation and increased cell apoptosis. Further studies showed that omega-3 also reduced GLUT1/4 protein content and cellular glucose uptake. Subsequent knockdown and overexpression of OCT4 using Oct4 siRNA and O4I2 (OCT4 activator) showed that OCT4 was involved in the regulations of omega-3 on GLUT1/4 expression and cell development. Our data demonstrate that omega-3 inhibits cellular development by down-regulating GLUT1/4 expression and glucose uptake in KGN cells, which are mediated through OCT4.

How cancer cells remodel lipid metabolism: strategies targeting transcription factors

Reprogramming of lipid metabolism has received increasing recognition as a hallmark of cancer cells because lipid dysregulation and the alteration of related enzyme profiles are closely correlated with oncogenic signals and malignant phenotypes, such as metastasis and therapeutic resistance. In this review, we describe recent findings that support the importance of lipids, as well as the transcription factors involved in cancer lipid metabolism. With recent advances in transcription factor analysis, including computer-modeling techniques, transcription factors are emerging as central players in cancer biology. Considering the limited number and the crucial role of transcription factors associated with lipid rewiring in cancers, transcription factor targeting is a promising potential strategy for cancer therapy.

Tumorigenic effect mediated by ROS/eicosanoids and their regulation on TP53 expression in a murine mammary gland adenocarcinoma

The aim of this study was to investigate the in vivo and in vitro effects of dietary ω-6 and ω-3 polyunsaturated fatty acids (PUFAs) and their derivatives on the expression of TP53 and their relationship with cellular proliferation and death in a murine mammary adenocarcinoma model. BALB/c mice were divided in three diet groups: chia oil (ChO) rich in ω-3, corn oil (CO) rich in ω-6/ω-3 and safflower oil (SO) rich in ω-6 and subcutaneously inoculated with LMM3 mammary tumor cell line. Results demonstrated that diets with higher concentration of omega-6 PUFAs induced an increment of linoleic and arachidonic acid on tumor cell membranes increasing ROS liberation, 12(S)-HHT generation, TP53, Ki67 expression and cell proliferation. However, diets enriched with high content in omega-3 PUFAs induced higher tumor cell apoptosis and tumor infiltration of CD3+ lymphocytes, lowest cell viability and proliferation. Dietary omega-3 PUFAs nutritional intervention can be used as a potential preventative strategy to inhibit the molecular signaling pathways involved in the mammary tumor growth process as the TP53.

Effects of Dietary n-3 and n-6 Polyunsaturated Fatty Acids in Inflammation and Cancerogenesis

The dietary recommendation encourages reducing saturated fatty acids (SFA) in diet and replacing them with polyunsaturated fatty acids (PUFAs) n-3 (omega-3) and n-6 (omega-6) to decrease the risk of metabolic disturbances. Consequently, excessive n-6 PUFAs content and high n-6/n-3 ratio are found in Western-type diet. The importance of a dietary n-6/n-3 ratio to prevent chronic diseases is linked with anti-inflammatory functions of linolenic acid (ALA, 18:3n-3) and longer-chain n-3 PUFAs. Thus, this review provides an overview of the role of oxylipins derived from n-3 PUFAs and oxylipins formed from n-6 PUFAs on inflammation. Evidence of PUFAs' role in carcinogenesis was also discussed. In vitro studies, animal cancer models and epidemiological studies demonstrate that these two PUFA groups have different effects on the cell growth, proliferation and progression of neoplastic lesions.

Low carbohydrate diets containing soy protein and fish oil slow the growth of established NNK-induced lung tumors

We recently found that a diet composed of 15% of total calories as carbohydrate (CHO), primarily as amylose, 35% soy protein and 50% fat, primarily as fish oil (FO) (15%Amylose/Soy/FO) was highly effective at preventing lung nodule formation in a nicotine-derived nitrosamine ketone (NNK)-induced lung cancer model. We asked herein whether adopting such a diet once cancers are established might also be beneficial. To test this, NNK-induced lung nodules were established in mice on a Western diet and the mice were then either kept on a Western diet or switched to various low CHO diets. Since we previously found that sedentary mice develop more lung nodules than active mice, we also compared the effect of exercise in this cancer progression model. We found that switching to a 15%Amylose/Soy/FO diet reduced lung nodules and slowed tumor growth with both 'active' and 'sedentary' mice. Ki67, cleaved caspase 3 and Terminal Deoxynucleotidyl Transferase-Mediated dUTP Nick End Labeling assays suggested that the efficacy of the 15%Amylose/Soy/FO in lowering tumor nodule count and size was not due to a reduction in tumor cell proliferation, but to an increase in apoptosis. The 15%Amylose/Soy/FO diet also significantly lowered liver fatty acid synthase and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 expression, pointing to a global metabolic switch from glycolysis to fatty acid oxidation. Mice fed the 15%Amylose/Soy/FO diet also had significantly reduced plasma levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor α. These results suggest that the 15%Amylose/Soy/FO diet may slow tumor growth by suppressing proinflammatory cytokines, inducing a metabolic switch away from glycolysis and inducing apoptosis in tumors.

Unsaturated fatty acids as a co-therapeutic agents in cancer treatment

Chemotherapy is standard treatments for many malignancies. However, in most cases, this method is not able to induce apoptosis and in many cases, with cancer recurrence, leads to patient death. There are several procedure to control and suppress malignant cells, but among these methods, administration of ɷ-3 fatty acids and ɷ-6 fatty due to their destructive effects on cancer cells is more prominent. Many clinical studies have shown beneficial effects of ɷ-3 and ɷ-6 fatty acids in cardiovascular disorders, asthma, rheumatoid arthritis, osteoporosis and in most cancers such as colon, breast, prostate and other malignancies. Studies showed that polyunsaturated fatty acids (PUFAs) have a toxic effect on cancer cells. However, the exact mechanism of how ɷ- fatty acids affect cancer cells is still unknown. In this review alternative issues of malignancies co-treatments agents such as PUFAs have been studied. Also, the latest known PUFAs mechanisms on malignancies have been described.

Role of Src/FAK in migration and invasion mediated by extracellular vesicles from MDA-MB-231 cells stimulated with linoleic acid

Linoleic acid (LA) is the most abundant polyunsaturated fatty acid in occidental diets, which mediate a variety of processes in human breast cancer cells, including migration and invasion. Extracellular vesicles (EVs) are vesicles released from endosomes and plasma membrane that are composed of a variety of molecules, including proteins, nucleic acids and lipids. EVs from cancer cells promote processes related with cancer progression. In the present study, we demonstrate that treatment of MDA-MB-231 cells with EVs from MDA-MB-231 cells stimulated with LA (LA EVs) promote migration and invasion via Src activity. LA EVs induce activation of FAK via Src activity and of Src and Akt2. LA EVs also induce the assembly of focal adhesions and MMP-9 secretion. These findings demonstrate that LA EVs mediate an autocrine and/or paracrine Src/FAK signaling pathway to promote migration and invasion.

Donkey milk inhibits triple-negative breast tumor progression and is associated with increased cleaved-caspase-3 expression

Donkey milk is considered an ideal substitute for human milk and is considered a potential complementary dairy product for the treatment of a variety of human diseases, including cancer. The purpose of this study was to investigate the inhibitory effect of donkey colostrum (DC) and mature milk (DM) on 4T1 triple-negative breast cancer (TNBC) tumors in mice. Metabolomics analyses showed that a total of 476 possible metabolites were found in both types of milk. Among them, 34 differential metabolites were identified, including 25 up-regulated and 9 down-regulated metabolites in the DC compared with DM. Both DC and DM are rich in many known anticancer constituents. The inhibitory effects of DC and DM on 4T1 primary tumors and the relative organ weight of the liver and lungs were determined by measuring the volume of primary tumors and weighing the liver and lungs. Both DC and DM significantly reduced both the primary tumor size and relative organ weight of the liver and lungs in 4T1 mice without affecting the bodyweight of mice. When the expression of cleaved caspase-3, Bax, and MMP2 was investigated by immunohistochemistry, the results showed that DC and DM inhibited the progression of 4T1 tumors by inducing the expression of cleaved-caspase-3 and Bax, and inhibiting the expression of MMP2 and CD31. Our data suggest that DC and DM inhibit the growth and metastasis of mouse 4T1 tumors by inducing apoptosis.

Low Levels of Omega-3 Long-Chain Polyunsaturated Fatty Acids Are Associated with Bone Metastasis Formation in Premenopausal Women with Breast Cancer: A Retrospective Study

In the present study, we investigated various biochemical, clinical, and histological factors associated with bone metastases in a large cohort of pre- and postmenopausal women with breast cancer. Two hundred and sixty-one consecutive women with breast cancer were included in this study. Breast adipose tissue specimens were collected during surgery. After having established the fatty acid profile of breast adipose tissue by gas chromatography, we determined whether there were differences associated with the occurrence of bone metastases in these patients. Regarding the clinical and histological criteria, a majority of the patients with bone metastases (around 70%) had tumors with a luminal phenotype and 59% of them showed axillary lymph node involvement. Moreover, we found a negative association between the levels of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) in breast adipose tissue and the development of bone metastases in premenopausal women. No significant association was observed in postmenopausal women. In addition to a luminal phenotype and axillary lymph node involvement, low levels of n-3 LC-PUFA in breast adipose tissue may constitute a risk factor that contributes to breast cancer bone metastases formation in premenopausal women.

Potential use of n-3 PUFAs to prevent oxidative stress-derived ototoxicity caused by platinum-based chemotherapy

Platinum-based compounds are widely used for the treatment of different malignancies due to their high effectiveness. Unfortunately, platinum-based treatment may lead to ototoxicity, an often-irreversible side effect without a known effective treatment and prevention plan. Platinum-based compound-related ototoxicity results mainly from the production of toxic levels of reactive oxygen species (ROS) rather than DNA-adduct formation, which has led to test strategies based on direct ROS scavengers to ameliorate hearing loss. However, favorable clinical results have been associated with several complications, including potential interactions with chemotherapy efficacy. To understand the contribution of the different cytotoxic mechanisms of platinum analogues on malignant cells and auditory cells, the particular susceptibility and response of both kinds of cells to molecules that potentially interfere with these mechanisms, is fundamental to develop innovative strategies to prevent ototoxicity without affecting antineoplastic effects. The n-3 long-chain polyunsaturated fatty acids (n-3 PUFAs) have been tried in different clinical settings, including with cancer patients. Nevertheless, their use to decrease cisplatin-induced ototoxicity has not been explored to date. In this hypothesis paper, we address the mechanisms of platinum compounds-derived ototoxicity, focusing on the differences between the effects of these compounds in neoplastic versus auditory cells. We discuss the basis for a strategic use of n-3 PUFAs to potentially protect auditory cells from platinum-derived injury without affecting neoplastic cells and chemotherapy efficacy.

Targeting FFA1 and FFA4 receptors in cancer-induced cachexia

Free fatty acid (FFA) receptors FFA1 and FFA4 are omega-3 molecular targets in metabolic diseases; however, their function in cancer cachexia remains unraveled. We assessed the role of FFA1 and FFA4 receptors in the mouse model of cachexia induced by Lewis lung carcinoma (LLC) cell implantation. Naturally occurring ligands such as α-linolenic acid (ALA) and docosahexaenoic acid (DHA), the synthetic FFA1/FFA4 agonists GW9508 and TUG891, or the selective FFA1 GW1100 or FFA4 AH7614 antagonists were tested. FFA1 and FFA4 expression and other cachexia-related parameters were evaluated. GW9508 and TUG891 decreased tumor weight in LLC-bearing mice. Regarding cachexia-related end points, ALA, DHA, and the preferential FFA1 agonist GW9508 rescued body weight loss. Skeletal muscle mass was reestablished by ALA treatment, but this was not reflected in the fiber cross-sectional areas (CSA) measurement. Otherwise, TUG891, GW1100, or AH7614 reduced the muscle fiber CSA. Treatments with ALA, GW9508, GW1100, or AH7614 restored white adipose tissue (WAT) depletion. As for inflammatory outcomes, ALA improved anemia, whereas GW9508 reduced splenomegaly. Concerning behavioral impairments, ALA and GW9508 rescued locomotor activity, whereas ALA improved motor coordination. Additionally, DHA improved grip strength. Notably, GW9508 restored abnormal brain glucose metabolism in different brain regions. The GW9508 treatment increased leptin levels, without altering uncoupling protein-1 downregulation in visceral fat. LLC-cachectic mice displayed FFA1 upregulation in subcutaneous fat, but not in visceral fat or gastrocnemius muscle, whereas FFA4 was unaltered. Overall, the present study shed new light on FFA1 and FFA4 receptors' role in metabolic disorders, indicating FFA1 receptor agonism as a promising strategy in mitigating cancer cachexia.

Targeting the tumor immune microenvironment with "nutraceuticals": From bench to clinical trials

The occurrence of immune effector cells in the tissue microenvironment during neoplastic progression is critical in determining tumor growth outcomes. On the other hand, tumors may also avoid immune system-mediated elimination by recruiting immunosuppressive leukocytes and soluble factors, which coordinate a tumor microenvironment that counteracts the efficiency of the antitumor immune response. Checkpoint inhibitor therapy results have indicated a way forward via activation of the immune system against cancer. Widespread evidence has shown that different compounds in foods, when administered as purified substances, can act as immunomodulators in humans and animals. Although there is no universally accepted definition of nutraceuticals, the term identifies a wide category of natural compounds that may impact health and disease statuses and includes purified substances from natural sources, plant extracts, dietary supplements, vitamins, phytonutrients, and various products with combinations of functional ingredients. In this review, we summarize the current knowledge on the immunomodulatory effects of nutraceuticals with a special focus on the cancer microenvironment, highlighting the conceptual benefits or drawbacks and subtle cell-specific effects of nutraceuticals for envisioning future therapies employing nutraceuticals as chemoadjuvants.

Comparing the In Vitro Antitumor, Antioxidant and Anti-Inflammatory Activities between Two New Very Long Chain Polyunsaturated Fatty Acids, Docosadienoic Acid (DDA) and Docosatrienoic Acid (DTA), and Docosahexaenoic Acid (DHA)

Very long chain polyunsaturated fatty acids (VLCPUFAs) are widely used as nutraceutical supplements for human health. Recently, a high level of two new VLCPUFAs, docosadienoic acid (DDA, 22:2n-6) and docosatrienoic acid (DTA, 22:3n-3), was produced in oilseed crop Brassica carinata using a biotechnology approach. This study investigated the functional properties of these two VLCPUFAs in human cells. Compared to docosahexaenoic acid (DHA), the golden standard in evaluating the health-promoting activities of VLCPUFAs, both DDA and DTA exhibited comparable or even better antitumor and antioxidant effects against human breast cancer SK-BR-3 and MDA-MB-231 cells. Especially, DTA elicited much stronger antioxidant and pro-apoptotic effects than DHA. Furthermore, DDA and DTA showed strong anti-inflammatory effects in human macrophages differentiated from monocyte THP-1 cells through lowering the protein expression levels of pro-inflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6), interferon γ (IFN-γ), monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor α (TNF-α). Future In Vivo and In Vivo studies are warranted to identify the mechanism of action (MOA) for the antitumor, antioxidant and anti-inflammatory functions of DDA and DTA and explore potential applications of these two VLCPUFAs as novel nutraceutical supplements in preventing inflammatory conditions, aging and even cancer.

Fatty Acid Mediators in the Tumor Microenvironment

Patients with cancer frequently overexpress inflammatory cytokines with an associated neutrophilia both of which may be downregulated by diets with high omega-3 polyunsaturated fatty acids (ω-3 PUFA). The anti-inflammatory activity of dietary ω-3 PUFA has been suggested to have anticancer properties and to improve survival of cancer patients. Currently, the majority of dietary research efforts do not differentiate between obesity and dietary fatty acid consumption as mediators of inflammatory cell expansion and tumor microenvironmental infiltration, initiation, and progression. In this chapter, we discuss the relationships between dietary lipids, inflammation, neoplasia and strategies to regulate these relationships. We posit that dietary composition, notably the ratio of ω-3 vs. ω-6 PUFA, regulates tumor initiation and progression and the frequency and sites of metastasis that, together, impact overall survival (OS). We focus on three broad topics: first, the role of dietary lipids in chronic inflammation and tumor initiation, progression, and regression; second, lipid mediators linking inflammation and cancer; and third, dietary lipid regulation of murine and human tumor initiation, progression, and metastasis.

Dietary Fat and Cancer-Which Is Good, Which Is Bad, and the Body of Evidence

A high-fat diet (HFD) induces changes in gut microbiota leading to activation of pro-inflammatory pathways, and obesity, as a consequence of overnutrition, exacerbates inflammation, a known risk factor not only for cancer. However, experimental data showed that the composition of dietary fat has a greater impact on the pathogenesis of cancer than the total fat content in isocaloric diets. Similarly, human studies did not prove that a decrease in total fat intake is an effective strategy to combat cancer. Saturated fat has long been considered as harmful, but the current consensus is that moderate intake of saturated fatty acids (SFAs), including palmitic acid (PA), does not pose a health risk within a balanced diet. In regard to monounsaturated fat, plant sources are recommended. The consumption of plant monounsaturated fatty acids (MUFAs), particularly from olive oil, has been associated with lower cancer risk. Similarly, the replacement of animal MUFAs with plant MUFAs decreased cancer mortality. The impact of polyunsaturated fatty acids (PUFAs) on cancer risk depends on the ratio between ω-6 and ω-3 PUFAs. In vivo data showed stimulatory effects of ω-6 PUFAs on tumour growth while ω-3 PUFAs were protective, but the results of human studies were not as promising as indicated in preclinical reports. As for trans FAs (TFAs), experimental data mostly showed opposite effects of industrially produced and natural TFAs, with the latter being protective against cancer progression, but human data are mixed, and no clear conclusion can be made. Further studies are warranted to establish the role of FAs in the control of cell growth in order to find an effective strategy for cancer prevention/treatment.

Therapeutic potentials and modulatory mechanisms of fatty acids in bone

Bone metabolism is a lifelong process that includes bone formation and resorption. Osteoblasts and osteoclasts are the predominant cell types associated with bone metabolism, which is facilitated by other cells such as bone marrow mesenchymal stem cells (BMMSCs), osteocytes and chondrocytes. As an important component in our daily diet, fatty acids are mainly categorized as long-chain fatty acids including polyunsaturated fatty acids (LCPUFAs), monounsaturated fatty acids (LCMUFAs), saturated fatty acids (LCSFAs), medium-/short-chain fatty acids (MCFAs/SCFAs) as well as their metabolites. Fatty acids are closely associated with bone metabolism and associated bone disorders. In this review, we summarized the important roles and potential therapeutic implications of fatty acids in multiple bone disorders, reviewed the diverse range of critical effects displayed by fatty acids on bone metabolism, and elucidated their modulatory roles and mechanisms on specific bone cell types. The evidence supporting close implications of fatty acids in bone metabolism and disorders suggests fatty acids as potential therapeutic and nutritional agents for the treatment and prevention of metabolic bone diseases.

Lipid and metabolic profiles in female dogs with mammary carcinoma receiving dietary fish oil supplementation

Background

Dyslipidemias induce angiogenesis and accelerate the development and in vitro growth of breast tumors. The aim of this study was to assess the lipid and metabolic profile of female dogs with mammary carcinomas and their correlations with body condition score and degree of tumor malignancy, as well as to study the effect of dietary fish oil supplementation on these animals.

Results

Overweight or obese dogs had more aggressive carcinomas and higher triglyceride (p = 0.0363), VLDL (p = 0.0181), albumin (p = 0.0188), globulin (p = 0.0145) and lactate (p = 0.0255) concentrations. There was no change in the lipid profile after supplementation with fish oil at any concentration. However, in relation to the metabolic profile, glucose (p = 0.0067), total protein (p = 0.0002) and globulin (p = 0.0002) concentrations were increased when 90% omega-3 fish oil was used as a dietary supplement.

Conclusion

Obese dogs showed altered lipid and metabolic profiles and more aggressive tumors, suggesting an important relationship between dyslipidemia and tumor aggressiveness. Supplementation with fish oil, rich in omega-3 fatty acids, may alter metabolic parameters in cancer patients.

Acylcarnitine: Useful biomarker for early diagnosis of hepatocellular carcinoma in non-steatohepatitis patients

BACKGROUND

Early diagnosis of hepatocellular carcinoma (HCC) is necessary to improve the prognosis of patients. However, the currently available tumor biomarkers are insufficient for the early detection of HCC. Acylcarnitine is essential in fatty acid metabolic pathways. A recent study reported that a high level of acylcarnitine may serve as a useful biomarker for the early diagnosis of HCC in steatohepatitis (SH) patients. In contrast, another study reported that the level of acetylcarnitine (AC2) - one of the acylcarnitine species - in non-SH patients with HCC was decreased vs that reported in those without HCC.

AIM

To investigate the usefulness of acylcarnitine as a biomarker for the early diagnosis of HCC in non-SH patients.

METHODS

Thirty-three non-SH patients (14 with HCC and 19 without HCC) were enrolled in this study. Blood samples were obtained from patients at the time of admission. The levels of acylcarnitine and AC2 in the serum were determined through tandem mass spectrometry. The levels of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR-2) were determined by enzyme-linked immunosorbent assay. Univariate and multivariate analyses were used to determine early diagnostic factors of HCC.

RESULTS

The level of acylcarnitine was significantly lower in non-SH patients with HCC vs those without HCC (P < 0.05). In contrast, the level of lens culinaris agglutinin-reactive fraction of α-fetoprotein (AFP) - AFP-L3% - was significantly higher in non-SH patients with HCC vs those without HCC (P < 0.05). However, the levels of total carnitine, free carnitine, AFP, des-γ-carboxy prothrombin, VEGF, and VEGFR-2 were not different between patients with and without HCC. The multivariate analysis showed that a low level of acylcarnitine was the only independent factor for the early diagnosis of HCC. The patients with a low level of AC2 had a significantly higher level of VEGF vs those with a high level of AC2 (P < 0.05).

CONCLUSION

The metabolic pathways of fatty acids may differ between SH HCC and non-SH HCC. Further studies are warranted to investigate these differences.

Dietary regulation of metastasis

The impact of diet and associated lifestyle choices on the risk of developing cancer is well established. However, whether these parameters also affect cancer recurrence and survival is less well investigated. Virtually nothing is known about the impact of diet on the development of metastases. It is therefore significant that a study in this issue of Clinical and experimental metastasis reports that breast cancer-bearing mice fed on a diet rich in long-chain omega-3 fatty acids had a lower incidence of metastasis than control mice, which was associated with modified infiltration of immune cells into the tumors. These findings should form the basis of further pre-clinical evaluation with a view to clinical application.

Reporting temporal fluctuations of hepatic C16 and C18 fatty acids during late gestation and early lactation in dromedary camel

Based on current knowledge, C16 and C18 fatty acids (FA) are considered the most functional FA in hepatic metabolism. Although these FAs have been satisfyingly investigated in cattle, other species such as camel have been neglected. For this reason, the current study was designed to scrutinize changing patterns of C16 and C18 FAs in 10 dromedary camels from the last 2 months of gestation to the first months of lactation. Camels were grazed on natural pasture and supplemented with a balanced ration. Liver biopsies were obtained through blind biopsy technique at about 60, 45, 30, and 15-day antepartum (AP), and at 3, 15, 30, 45, and 60 post-partum (PP). Data were analyzed by the ANOVA procedure of SPSS with repeated measurements. From 15-day AP, saturated FA content of the liver declined (P < 0.01) and 15-day PP reached its peak (P = 0.02). At 30-day PP it went down (P < 0.01), and re-elevated at 45-day PP (P < 0.01) but remained at a steady state for the duration of the study. Mono-unsaturated and polyunsaturated FA content of hepatic tissue were constant throughout AP, albeit observed to peak at 15-day AP compared with 45 (P = 0.04) and 30-day AP (P < 0.01) for mono-unsaturated FAs, and with 60-, 45-, and 30-day AP (P ≤ 0.01) for polyunsaturated FAs. The palmitic acid content of the liver reached a nadir at 30-day AP (P < 0.01), increased sharply (P < 0.01) at the next sampling time-point, and had a trend to escalate until 3-day PP. Palmitoleic acid levels were unchanged from 60- to 30-day AP, decreased at 15 AP and 3-day PP, increased at 15-day PP, then remained constant until the end of the study period (P ≤ 0.04). Stearic acid content started to grow at 15-day AP and reached its peak at 15-day PP (P < 0.01). At 30-day PP, stearic level in liver dropped abruptly (P < 0.01), then intensified at 45-day PP and did not change after; hepatic content of stearic acid was lower during AP compared with PP time-points. Other C18 FAs changed significantly during the study period. These results suggest that parturition could have a profound effect on FA composition and other metabolites in camel liver. Further research is required to establish the metabolic mechanism behind these changes.

Immune regulation and anti-cancer activity by lipid inflammatory mediators

Rodent and clinical studies have documented that myeloid cell infiltration of tumors is associated with poor outcomes, neutrophilia and lymphocytopenia. This contrasts with increased lymphocyte infiltration of tumors, which is correlated with improved outcomes. Lifestyle parameters, such as obesity and diets with high levels of saturated fat and/or omega (ω)-6 polyunsaturated fatty acids (PUFAs), can influence these inflammatory parameters, including an increase in extramedullary myelopoiesis (EMM). While tumor secretion of growth factors (GFs) and chemokines regulate tumor-immune-cell crosstalk, lifestyle choices also contribute to inflammation, abnormal pathology and leukocyte infiltration of tumors. A relationship between obesity and high-fat diets (notably saturated fats in Western diets) and inflammation, tumor incidence, metastasis and poor outcomes is generally accepted. However, the mechanisms of dietary promotion of an inflammatory microenvironment and targeted drugs to inhibit the clinical sequelae are poorly understood. Thus, modifications of obesity and dietary fat may provide preventative or therapeutic approaches to control tumor-associated inflammation and disease progression. Currently, the majority of basic and clinical research does not differentiate between obesity and fatty acid consumption as mediators of inflammatory and neoplastic processes. In this review, we discuss the relationships between dietary PUFAs, inflammation and neoplasia and experimental strategies to improve our understanding of these relationships. We conclude that dietary composition, notably the ratio of ω-3 vs ω-6 PUFA regulates tumor growth and the frequency and sites of metastasis that together, impact overall survival (OS) in mice.