Fatty Acids and Membrane Lipidomics in Oncology: A Cross-Road of Nutritional, Signaling and Metabolic Pathways

Comprehensive determination of fatty acids in real samples without derivatization by DMU-SPME-GC methods

The comprehensive determination of fatty acids without derivatization, including short-chain fatty acids (SCFAs), medium-chain fatty acids (MCFAs) and long-chain fatty acids (LCFAs), is a big challenge but powerful for lipidomics in biology, food, and environment. Herein, the dual mode unity solid-phase microextraction (DMU-SPME) combined with gas chromatography-flame ionization detector (GC-FID) or mass spectrometry (MS) was proposed as a powerful method for the determination of comprehensive free fatty acids in real samples. Under the optimized DMU-SPME conditions, the proposed method has good linearity (R2 ≥ 0.994) and low limits of determination (0.01-0.14 mg/L). In the stability analysis, the intra-day relative standard deviation was 1.39-12.43 %, and the inter-day relative standard deviation was 2.84-10.79 %. The recoveries of selected 10 fatty acids in real samples ranged from 90.18 % to 110.75 %, indicating that the method has good accuracy. Fatty acids ranging from C2 to C22 were detected in real samples by the untargeted determination method of DMU-SPME combined with gas chromatography-mass spectrometry (GC-MS). The DMU-SPME method proposed in this study can be used for lipid metabolism analysis and free fatty acid determination in the fields of biology, food, and environment.

The role of nonesterified fatty acids in cancer biology: Focus on tryptophan and related metabolism

Plasma nonesterified fatty acids (NEFA) are elevated in cancer, because of decreased albumin levels and of fatty acid oxidation, and increased fatty acid synthesis and lipolysis. Albumin depletion and NEFA elevation maximally release albumin-bound tryptophan (Trp) and increase its flux down the kynurenine pathway, leading to increased production of proinflammatory kynurenine metabolites, which tumors use to undermine T-cell function and achieve immune escape. Activation of the aryl hydrocarbon receptor by kynurenic acid promotes extrahepatic Trp degradation by indoleamine 2,3-dioxygenase and leads to upregulation of poly (ADP-ribose) polymerase, activation of which and also of SIRT1 (silent mating type information regulation 2 homolog 1) could lead to depletion of NAD+ and ATP, resulting in cell death. NEFA also modulate heme synthesis and degradation, changes in which impact homocysteine metabolism and production of reduced glutathione and hydrogen sulphide. The significance of the interactions between heme and homocysteine metabolism in cancer biology has received little attention. Targeting Trp disposition in cancer to prevent the NEFA effects is suggested.

Death and the desaturase: Implication of Stearoyl-CoA desaturase-1 in the mechanisms of cell stress, apoptosis, and ferroptosis

Growth and proliferation of normal and cancerous cells necessitate a finely-tuned regulation of lipid metabolic pathways to ensure the timely supply of structural, energetic, and signaling lipid molecules. The synthesis and remodeling of lipids containing fatty acids with an appropriate carbon length and insaturation level are required for supporting each phase of the mechanisms of cell replication and survival. Mammalian Stearoyl-CoA desaturases (SCD), particularly SCD1, play a crucial role in modulating the fatty acid composition of cellular lipids, converting saturated fatty acids (SFA) into monounsaturated fatty acids (MUFA) in the endoplasmic reticulum (ER). Extensive research has elucidated in great detail the participation of SCD1 in the molecular mechanisms that govern cell replication in normal and cancer cells. More recently, investigations have shed new light on the functional and regulatory role of the Δ9-desaturase in the processes of cell stress and cell death. This review will examine the latest findings on the involvement of SCD1 in the molecular pathways of cell survival, particularly on the mechanisms of ER stress and autophagy, as well in apoptotic and non-apoptotic cell death.

Palmitic Acid Exerts Anti-Tumorigenic Activities by Modulating Cellular Stress and Lipid Droplet Formation in Endometrial Cancer

Epidemiological and clinical evidence have extensively documented the role of obesity in the development of endometrial cancer. However, the effect of fatty acids on cell growth in endometrial cancer has not been widely studied. Here, we reported that palmitic acid significantly inhibited cell proliferation of endometrial cancer cells and primary cultures of endometrial cancer and reduced tumor growth in a transgenic mouse model of endometrial cancer, in parallel with increased cellular stress and apoptosis and decreased cellular adhesion and invasion. Inhibition of cellular stress by N-acetyl-L-cysteine effectively reversed the effects of palmitic acid on cell proliferation, apoptosis, and invasive capacity in endometrial cancer cells. Palmitic acid increased the intracellular formation of lipid droplets in a time- and dose-dependent manner. Depletion of lipid droplets by blocking DGAT1 and DGAT2 effectively increased the ability of palmitic acid to inhibit cell proliferation and induce cleaved caspase 3 activity. Collectively, this study provides new insight into the effect of palmitic acid on cell proliferation and invasion and the formation of lipid droplets that may have potential clinical relevance in the treatment of obesity-driven endometrial cancer.

Cellular interactions in tumor microenvironment during breast cancer progression: new frontiers and implications for novel therapeutics

The breast cancer tumor microenvironment (TME) is dynamic, with various immune and non-immune cells interacting to regulate tumor progression and anti-tumor immunity. It is now evident that the cells within the TME significantly contribute to breast cancer progression and resistance to various conventional and newly developed anti-tumor therapies. Both immune and non-immune cells in the TME play critical roles in tumor onset, uncontrolled proliferation, metastasis, immune evasion, and resistance to anti-tumor therapies. Consequently, molecular and cellular components of breast TME have emerged as promising therapeutic targets for developing novel treatments. The breast TME primarily comprises cancer cells, stromal cells, vasculature, and infiltrating immune cells. Currently, numerous clinical trials targeting specific TME components of breast cancer are underway. However, the complexity of the TME and its impact on the evasion of anti-tumor immunity necessitate further research to develop novel and improved breast cancer therapies. The multifaceted nature of breast TME cells arises from their phenotypic and functional plasticity, which endows them with both pro and anti-tumor roles during tumor progression. In this review, we discuss current understanding and recent advances in the pro and anti-tumoral functions of TME cells and their implications for developing safe and effective therapies to control breast cancer progress.

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.

Multiomics characterization of fatty acid metabolism for the clinical management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a prevalent malignancy and there is a lack of effective biomarkers for HCC diagnosis. Living organisms are complex, and different omics molecules interact with each other to implement various biological functions. Genomics and metabolomics, which are the top and bottom of systems biology, play an important role in HCC clinical management. Fatty acid metabolism is associated with malignancy, prognosis, and immune phenotype in cancer, which is a potential hallmark in malignant tumors. In this study, the genes and metabolites related to fatty acid metabolism were thoroughly investigated by a dynamic network construction algorithm named EWS-DDA for the early diagnosis and prognosis of HCC. Three gene ratios and eight metabolite ratios were identified by EWS-DDA as potential biomarkers for HCC clinical management. Further analysis using biological analysis, statistical analysis and document validation in the discovery and validation sets suggested that the selected potential biomarkers had great clinical prognostic value and helped to achieve effective early diagnosis of HCC. Experimental results suggested that in-depth evaluation of fatty acid metabolism from different omics viewpoints can facilitate the further understanding of pathological alterations associated with HCC characteristics, improving the performance of early diagnosis and clinical prognosis.

Fatty acid profiles and Delta9 desaturase (stearoyl-CoA desaturase; SCD 1) expression in adipose tissue surrounding benign and malignant breast tumors

The progression of tumors occurs through interactions between the tumor and the stroma. Understanding the role of adipose tissue (AT), as the main component of the breast tumor microenvironment (TME) in the development of cancer, is crucial for the early detection of breast cancer (BC). This study compared the FA profiles, desaturase index (DI), and stearoyl CoA desaturase 1 (SCD1) mRNA levels in the AT that surrounds tumors in women with BC and benign breast disease (BBD). Specimens were collected from 40 Iranian women who had undergone breast surgery. These women were age- and BMI-matched and were divided into two groups: BC (n = 20) and BBD (n = 20). Gas chromatography and quantitative real-time PCR were used to analyze the FA profiles and SCD1 mRNA levels, respectively. The DI was calculated by dividing the amounts of monounsaturated FAs by the amount of saturated FA. There were no significant differences in age and BMI between women with BC and BBD. The FA profiles and DI were also similar in both groups. However, mRNA levels of SCD1 were found to be 5 times higher in the breast AT of BC than in the breast AT of BBD (p < 0.0001). We showed that SCD1 was significantly upregulated in the AT surrounding BC tumors, even though the DI and FA profiles were unchanged compared to those in the AT of BBD patients. It is important to note that the breast AT of women with BBD has previously been overlooked and warrants further studies.

The expanding organelle lipidomes: current knowledge and challenges

Lipids in cell membranes and subcellular compartments play essential roles in numerous cellular processes, such as energy production, cell signaling and inflammation. A specific organelle lipidome is characterized by lipid synthesis and metabolism, intracellular trafficking, and lipid homeostasis in the organelle. Over the years, considerable effort has been directed to the identification of the lipid fingerprints of cellular organelles. However, these fingerprints are not fully characterized due to the large variety and structural complexity of lipids and the great variability in the abundance of different lipid species. The process becomes even more challenging when considering that the lipidome differs in health and disease contexts. This review summarizes the information available on the lipid composition of mammalian cell organelles, particularly the lipidome of the nucleus, mitochondrion, endoplasmic reticulum, Golgi apparatus, plasma membrane and organelles in the endocytic pathway. The lipid compositions of extracellular vesicles and lamellar bodies are also described. In addition, several examples of subcellular lipidome dynamics under physiological and pathological conditions are presented. Finally, challenges in mapping organelle lipidomes are discussed.

Study of anti-tumorigenic actions of essential fatty acids in a murine mammary gland adenocarcinoma by micro-XRF

In the present work, a statistical experiment based on the microscopy X-ray fluorescence technique was developed to evaluate the effect of diets rich in ω-3 and ω-6 polyunsaturated fatty acids on tumour tissues. Relative variations on the local content of P, S, Ca, Fe, Cu and Zn were analysed in the experiment. Neoplastic tissues were obtained from mammary gland adenocarcinomas inoculated in mice belonging to three different dietary groups: normal, rich in ω-3 and in ω-6 polyunsaturated fatty acids. Slices of 30 microns thick sections of these samples were scanned in the air atmosphere in areas of 5 mm × 5 mm with a spatial resolution of 50 microns using synchrotron radiation. Principal component analysis was employed to analyse the correlation between the X-ray fluorescence signals of P, S, Ca, Fe, Cu and Zn. The subsequent application of the K-means clustering was used for the automatic segmentation of the image scans. By comparison with conventional histological analysis, the clusters were positively identified as tumour parenchyma, transition and necrotic region. The calculation of the mean content of P, S, Ca, Fe, Cu, and Zn in these regions showed that dietary polyunsaturated fatty acids modify elemental content of tumour parenchyma, suggesting its involvement in the antitumour effects of chia oil and protumour effects of safflower oil.

Clinical lipidomics in the era of the big data

Lipidomics as a branch of metabolomics provides unique information on the complex lipid profile in biological materials. In clinically focused studies, hundreds of lipids together with available clinical information proved to be an effective tool in the discovery of biomarkers and understanding of pathobiochemistry. However, despite the introduction of lipidomics nearly twenty years ago, only dozens of big data studies using clinical lipidomics have been published to date. In this review, we discuss the lipidomics workflow, statistical tools, and the challenges of standartisation. The consequent summary divided into major clinical areas of cardiovascular disease, cancer, diabetes mellitus, neurodegenerative and liver diseases is demonstrating the importance of clinical lipidomics. In these publications, the potential of lipidomics for prediction, diagnosis or finding new targets for the treatment of selected diseases can be seen. The first of these results have already been implemented in clinical practice in the field of cardiovascular diseases, while in other areas we can expect the application of the results summarized in this review in the near future.

Inhibition of triple negative breast cancer-associated inflammation and progression by N- acylethanolamine acid amide hydrolase (NAAA)

Triple-negative breast cancer (TNBC) is associated with high mortality due to the high expression of pro-inflammatory cytokines and lack of targeted therapies. N-acylethanolamine acid amidase (NAAA) is an N-terminal cysteine hydrolase that promotes inflammatory responses through the deactivation of Palmitoylethanolamide (PEA), an endogenous bioactive lipid mediator. Here, we examined NAAA expression in TNBC cells (MDA-MB-231 and MDA-MB-BrM2 cells) and the effects of NAAA inhibition on TNBC tumor growth, using a selective NAAA inhibitor AM11095 (IC₅₀ = 20 nM). TNBC cells expressed elevated levels of full-length and splice mRNAs naaa variants. TNBC cells also express the N-acyl ethanol amides and elevated levels of the two fatty acid cores arachidonic (AA) and docosahexaenoic (DHA). PEA or AM11095 inhibited the secretion of IL-6 and IL-8, reduced the activation of the NF-kB pathway, decreased the expression of VEGF and Placental growth factor (PLGF) in TNBCs, and inhibited tumor cell migration in vitro. Using cellular magnetic resonance imaging (MRI), body images of mice administered with human MDA-MB-BrM2 cells treated with AM11095 showed a significant decrease in tumor numbers with a lower volume of tumors and increased mice survival. Mice untreated or treated with vehicle control showed a high number of tumors with high volumes in multiple organs. Thus, NAAA inhibition may constitute a potential therapeutic approach in the management of TNBC-associated inflammation and tumor growth.

Spatial metabolomics on liver cirrhosis to hepatocellular carcinoma progression

Background

Hepatocellular carcinoma (HCC) is one of the deadliest cancers and is mainly developed from chronic liver diseases such as hepatitis-B infection-associated liver cirrhosis (LC). The progression from LC to HCC makes the detection of diagnostic biomarkers to be challenging. Hence, there have been constant efforts to improve on identifying the critical and predictive changes accompanying the disease progression.

Methods

In this study, we looked to using the mass spectrometry mediated spatial metabolomics technique to simultaneous examine hundreds of metabolites in an untargeted fashion. Additionally, metabolic profiles were compared between six subregions within the HCC tissue to collect spatial information.

Results

Through those metabolites, altered metabolic pathways in LC and HCC were identified. Specifically, the amino acid metabolisms and the glycerophospholipid metabolisms experienced the most changes. Many of the altered metabolites and metabolic pathways were able to be connected through the urea cycle.

Conclusions

The identification of the key metabolites and pathways can expand our knowledge on HCC metabolic reprogramming and help us exam potential biomarkers for earlier detection of the malignant disease progression.

Critical Review on Fatty Acid-Based Food and Nutraceuticals as Supporting Therapy in Cancer

Fatty acids have an important place in both biological and nutritional contexts and, from a clinical point of view, they have known consequences for diseases’ onset and development, including cancer. The use of fatty acid-based food and nutraceuticals to support cancer therapy is a multidisciplinary subject, involving molecular and clinical research. Knowledge regarding polyunsaturated fatty acids essentiality/oxidizability and the role of lipogenesis-desaturase pathways for cell growth, as well as oxidative reactivity in cancer cells, are discussed, since they can drive the choice of fatty acids using their multiple roles to support antitumoral drug activity. The central role of membrane fatty acid composition is highlighted for the application of membrane lipid therapy. As fatty acids are also known as biomarkers of cancer onset and progression, the personalization of the fatty acid-based therapy is also possible, taking into account other important factors such as formulation, bioavailability and the distribution of the supplementation. A holistic approach emerges combining nutra- and pharma-strategies in an appropriate manner, to develop further knowledge and applications in cancer therapy.

Lipidomic and Membrane Mechanical Signatures in Triple-Negative Breast Cancer: Scope for Membrane-Based Theranostics

Triple-negative breast cancer (TNBC) is a highly aggressive form of breast cancer associated with poor prognosis, higher grade, and a high rate of metastatic occurrence. Limited therapeutic interventions and the compounding issue of drug resistance in triple-negative breast cancer warrants the discovery of novel therapeutic targets and diagnostic modules. To this view, in addition to proteins, lipids also regulate cellular functions via the formation of membranes that modulate membrane protein function, diffusion, and their localization; thus, orchestrating signaling hot spots enriched in specific lipids/proteins on cell membranes. Lipid deregulation in cancer leads to reprogramming of the membrane dynamics and functions impacting cell proliferation, metabolism, and metastasis, providing exciting starting points for developing lipid-based approaches for treating TNBC. In this review, we provide a detailed account of specific lipidic changes in breast cancer, link the altered lipidome with membrane structure and mechanical properties, and describe how these are linked to subsequent downstream functions implicit in cancer progression, metastasis, and chemoresistance. At the fundamental level, we discuss how the lipid-centric findings in TNBC are providing cues for developing lipid-inspired theranostic strategies while bridging existing gaps in our understanding of the functional involvement of lipid membranes in cancer.

Elevation of fatty acid desaturase 2 in esophageal adenocarcinoma increases polyunsaturated lipids and may exacerbate bile acid-induced DNA damage

Background

The risk of esophageal adenocarcinoma (EAC) is associated with gastro‐esophageal reflux disease (GERD) and obesity. Lipid metabolism‐targeted therapies decrease the risk of progressing from Barrett's esophagus (BE) to EAC, but the precise lipid metabolic changes and their roles in genotoxicity during EAC development are yet to be established.

Methods

Esophageal biopsies from the normal epithelium (NE), BE, and EAC, were analyzed using concurrent lipidomics and proteomics (n = 30) followed by orthogonal validation on independent samples using RNAseq transcriptomics (n = 22) and immunohistochemistry (IHC, n = 80). The EAC cell line FLO‐1 was treated with FADS2 selective inhibitor SC26196, and/or bile acid cocktail, followed by immunofluorescence staining for γH2AX.

Results

Metabolism‐focused Reactome analysis of the proteomics data revealed enrichment of fatty acid metabolism, ketone body metabolism, and biosynthesis of specialized pro‐resolving mediators in EAC pathogenesis. Lipidomics revealed progressive alterations (NE‐BE‐EAC) in glycerophospholipid synthesis with decreasing triglycerides and increasing phosphatidylcholine and phosphatidylethanolamine, and sphingolipid synthesis with decreasing dihydroceramide and increasing ceramides. Furthermore, a progressive increase in lipids with C20 fatty acids and polyunsaturated lipids with ≥4 double bonds were also observed. Integration with transcriptome data identified candidate enzymes for IHC validation: Δ4‐Desaturase, Sphingolipid 1 (DEGS1) which desaturates dihydroceramide to ceramide, and Δ5 and Δ6‐Desaturases (fatty acid desaturases, FADS1 and FADS2), responsible for polyunsaturation. All three enzymes showed significant increases from BE through dysplasia to EAC, but transcript levels of DEGS1 were decreased suggesting post‐translational regulation. Finally, the FADS2 selective inhibitor SC26196 significantly reduced polyunsaturated lipids with three and four double bonds and reduced bile acid‐induced DNA double‐strand breaks in FLO‐1 cells in vitro.

Conclusions

Integrated multiomics revealed sphingolipid and phospholipid metabolism rewiring during EAC development. FADS2 inhibition and reduction of the high polyunsaturated lipids effectively protected EAC cells from bile acid‐induced DNA damage in vitro, potentially through reduced lipid peroxidation.

Tissue Imprinting on 2D Nanoflakes-Capped Silicon Nanowires for Lipidomic Mass Spectrometry Imaging and Cancer Diagnosis

Spatially resolved tissue lipidomics is essential for accurate intraoperative and postoperative cancer diagnosis by revealing molecular information in the tumor microenvironment. Matrix-free laser desorption ionization mass spectrometry imaging (LDI-MSI) is an emerging attractive technology for label-free visualization of metabolites distributions in biological specimens. However, the development of LDI-MSI technology that could conveniently and authentically reveal molecular distribution on tissue samples is still a challenge. Herein, we present a tissue imprinting technology by retaining tissue lipids on 2D nanoflakes-capped silicon nanowires (SiNWs) for further mass spectrometry imaging and cancer diagnosis. The 2D nanoflakes were prepared by liquid exfoliation of molybdenum disulfide (MoS₂) with nitrogen-doped graphene quantum dots (NGQDs), which serve as both intercalation agent and dispersant. The obtained NGQD@MoS₂ nanoflakes were then decorated on the tip of vertical SiNWs, forming a hybrid NGQD@MoS₂/SiNWs nanostructure, which display excellent lipid extraction ability, enhanced LDI efficiency and molecule imaging capability. The peak number and total ion intensity of different lipids species on animal lung tissues obtained by tissue imprinting LDI-MSI on NGQD@MoS₂/SiNWs were ∼4-5 times greater than those on SiNWs substrate. As a proof-of-concept demonstration, the NGQD@MoS₂/SiNWs nanostructure was further applied to visualize phospholipids on sliced non small cell lung cancer (NSCLC) tissue along with the adjacent normal tissue. On the basis of selected feature lipids and machine learning algorithm, a prediction model was constructed to discriminate NSCLC tissues from the adjacent normal tissues with an accuracy of 100% for the discovery cohort and 91.7% for the independent validation cohort.

Effects of Oxygen Tension for Membrane Lipidome Remodeling of Cockayne Syndrome Cell Models

Oxygen is important for lipid metabolism, being involved in both enzymatic transformations and oxidative reactivity, and is particularly influent when genetic diseases impair the repair machinery of the cells, such as described for Cockayne syndrome (CS). We used two cellular models of transformed fibroblasts defective for CSA and CSB genes and their normal counterparts, grown for 24 h under various oxygen tensions (hyperoxic 21%, physioxic 5% and hypoxic 1%) to examine the fatty acid-based membrane remodeling by GC analysis of fatty acid methyl esters derived from membrane phospholipids. Overall, we first distinguished differences due to oxygen tensions: (a) hyperoxia induced a general boost of desaturase enzymatic activity in both normal and defective CSA and CSB cell lines, increasing monounsaturated fatty acids (MUFA), whereas polyunsaturated fatty acids (PUFA) did not undergo oxidative consumption; (b) hypoxia slowed down desaturase activities, mostly in CSA cell lines and defective CSB, causing saturated fatty acids (SFA) to increase, whereas PUFA levels diminished, suggesting their involvement in hypoxia-related signaling. CSB-deprived cells are the most sensitive to oxidation and CSA-deprived cells are the most sensitive to the radical-based formation of trans fatty acids (TFA). The results point to the need to finely differentiate biological targets connected to genetic impairments and, consequently, suggest the better definition of cell protection and treatments through accurate molecular profiling that includes membrane lipidomes.

Evening Primrose Oil Enhances Tamoxifen's Anticancer Activity against Breast Cancer Cells by Inducing Apoptosis, Inhibiting Angiogenesis, and Arresting the Cell Cycle

BACKGROUND

Despite advancements in cancer treatment, breast cancer (BC) is still one of the leading causes of death among women. The majority of anti-breast-cancer medications induce serious side effects and multidrug resistance. Although several natural compounds, such as evening primrose oil (EPO), have been shown to have anticancer properties when used alone, their combination with the anticancer medicine tamoxifen (TAM) has yet to be investigated. The present study aimed to investigate the anticancer efficacy of EPO, alone or in combination with TAM, in the BC cell lines MCF-7 and MDA-MB-231, as well as to elucidate the mechanism of action.

METHODS

The MTT assay was used to investigate the cytotoxic effect of EPO on the two cell lines, and we discovered an acceptable IC50 that was comparable to TAM. The ELISA, qRT-PCR, flow cytometry and colorimetric techniques were used.

RESULTS

The combination of EPO and TAM suppressed the VEGF level, VEGF gene expression and Cyclin D1 signaling pathways, arrested the cell cycle, and induced the apoptotic signaling pathways by increasing the Bax/Bcl-2 ratio and caspase 3 activity; this revealed significant anti-tumor activity.

CONCLUSIONS

The most significant finding of this study was the confirmation of the anticancer activity of the natural product EPO, which potentiated the activity of the anticancer drug TAM against MCF-7 and MDA-MB-231 BC cell lines through the induction of apoptosis, inhibiting angiogenesis and halting cell proliferation.

Targeting stearoyl-CoA desaturase in solid tumors

Cancer cells are demarcated from normal cells by distinct biological hallmarks, including the reprogramming of metabolic processes. One of the key players involved in metabolic reprogramming is stearoyl-CoA desaturase (SCD), which converts saturated fatty acids to monounsaturated fatty acids in an oxygen-dependent reaction that is crucial for maintaining fatty acid homeostasis. As such, SCD has been identified as a potential therapeutic target in numerous types of cancers, and its inhibition suppresses cancer cell growth in vitro and in vivo. This review summarizes the evidence implicating SCD in cancer progression and proposes novel therapeutic strategies for targeting SCD in solid tumors.

Relationship Between Fish Oil Use and Incidence of Primary Liver Cancer: Findings From a Population-Based Prospective Cohort Study

Background: N-3 long-chain polyunsaturated fatty acids (LCPUFAs) prevented non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC) in studies of mouse models. We examined prospective relationships between fish oil use and risk of primary liver cancer and the major histological subtypes, such as HCC and intrahepatic cholangiocarcinoma (ICC).

Methods: We included 434,584 middle-aged and older men and women who were free of cancer at recruitment of the UK Biobank (2006–2010). Information on fish oil use and other dietary habits was collected via questionnaires. Cox proportional hazards models were used to compute the hazard ratio (HR) and 95% CI of liver cancer associated with fish oil use, with adjustment for socio-demographic, lifestyle, dietary, and other clinical risk factors.

Results: At baseline, 31.4% of participants reported regular use of fish oil supplements. During a median of 7.8 years of follow-up, 262 incident liver cancer cases were identified, among which 127 were HCC and 110 were ICC cases. As compared with non-users, fish oil users had a significantly 44% (95% CI: 25–59%) lower risk of total liver cancer, and 52% (95% CI: 24–70%) and 40% (95% CI: 7–61%) lower risk of HCC and ICC, respectively. Higher intake of oily fish also was associated with a lower risk of HCC (≥2 vs. <1 serving/week: HR = 0.46; 95% CI: 0.23–0.96; P-trend = 0.027) but not ICC (P-trend = 0.96).

Conclusion: Habitual use of fish oil supplements was associated lower risk of primary liver cancer regardless of cancer histological subtypes, potentially supporting a beneficial role of dietary n-3 LCPUFAs in liver cancer prevention.

Sapienic Acid Metabolism Influences Membrane Plasticity and Protein Signaling in Breast Cancer Cell Lines

The importance of sapienic acid (6c-16:1), a monounsaturated fatty acid of the n-10 family formed from palmitic acid by delta-6 desaturase, and of its metabolism to 8c-18:1 and sebaleic acid (5c,8c-18:2) has been recently assessed in cancer. Data are lacking on the association between signaling cascades and exposure to sapienic acid comparing cell lines of the same cancer type. We used 50 μM sapienic acid supplementation, a non-toxic concentration, to cultivate MCF-7 and 2 triple-negative breast cancer cells (TNBC), MDA-MB-231 and BT-20. We followed up for three hours regarding membrane fatty acid remodeling by fatty acid-based membrane lipidome analysis and expression/phosphorylation of EGFR (epithelial growth factor receptor), mTOR (mammalian target of rapamycin) and AKT (protein kinase B) by Western blotting as an oncogenic signaling cascade. Results evidenced consistent differences among the three cell lines in the metabolism of n-10 fatty acids and signaling. Here, a new scenario is proposed for the role of sapienic acid: one based on changes in membrane composition and properties, and the other based on changes in expression/activation of growth factors and signaling cascades. This knowledge can indicate additional players and synergies in breast cancer cell metabolism, inspiring translational applications of tailored membrane lipid strategies to assist pharmacological interventions.

New non-invasive approaches to the diagnosis of lymph node metastases from breast cancer by mass spectrometry

Early diagnosis of metastasis makes it possible to select the optimal treatment protocol and improve patient survival. Noninvasive and minimally invasive diagnostic techniques help to make a diagnosis with minimal damage to the body. The study was aimed to find biomarkers, being the hallmarks of the metastatic process initiation, and to develop a diagnostic model based on the plasma lipid profile using liquid chromatography-mass spectrometry. We studied blood plasma of 55 patients, 28 of them were diagnosed with the regional lymph node metastasis; the control group comprised 27 patients. The levels of lipids, belonging to the groups, such as oxidized lipids and sphingomyelins, in patients with metastases were significantly higher and significantly lower, respectively. The lipid panels were created by multivariate analysis, and the models based on these panels showed sensitivity and specificity of 79 and 74% (positive ion mode), and of 50 and 85% (negative ion mode) in leave-one-out cross-validation.

Lipidomic landscape in cancer: Actionable insights for membrane-based therapy and diagnoses

Cancer cells display altered cellular lipid metabolism, including disruption in endogenous lipid synthesis, storage, and exogenous uptake for membrane biogenesis and functions. Altered lipid metabolism and, consequently, lipid composition impacts cellular function by affecting membrane structure and properties, such as fluidity, rigidity, membrane dynamics, and lateral organization. Herein, we provide an overview of lipid membranes and how their properties affect cellular functions. We also detail how the rewiring of lipid metabolism impacts the lipidomic landscape of cancer cell membranes and influences the characteristics of cancer cells. Furthermore, we discuss how the altered cancer lipidome provides cues for developing lipid-inspired innovative therapeutic and diagnostic strategies while improving our limited understanding of the role of lipids in cancer initiation and progression. We also present the arcade of membrane characterization techniques to cement their relevance in cancer diagnosis and monitoring of treatment response.

Omega 6 polyunsaturated fatty acids in red blood cell membrane are associated with xerostomia and taste loss in patients with breast cancer

Chemosensory and physical complaints are common disorders in cancer patients under chemotherapy treatments that may affect the food intake, leading to a decreased quality of life. Lipid metabolism is a major pathway of cancer proliferation, where erythrocyte membrane phospholipids and their fatty acid composition are promising tools for monitoring metabolic pathways. Relationship between lipid profile in erythrocyte membrane phospholipids and chemosensory alterations in 44 newly diagnosed patients with breast cancer was here investigated. Smell changes and xerostomia were the most common complaints, with xerostomia as the main influencing factor on the development of other taste disorders. Lipid profiles revealed significant negative correlation between diminution of linoleic acid levels and xerostomia as well as positive correlation between increased arachidonic acid and salty taste. The involvement of these polyunsaturated lipids suggests the importance of oxidative and nutritional conditions of cancer patients, which can affect the molecular status for taste signals.

Nuclear Receptor-Mediated Metabolic Reprogramming and the Impact on HR+ Breast Cancer

Simple Summary

Breast cancer is the most commonly diagnosed and second leading cause of cancer-related deaths in women in the United States, with hormone receptor positive (HR+) tumors representing more than two-thirds of new cases. Recent evidence has indicated that dysregulation of multiple metabolic programs, which can be driven through nuclear receptor activity, is essential for tumor genesis, progression, therapeutic resistance and metastasis. This study will review the current advances in our understanding of the impact and implication of altered metabolic processes driven by nuclear receptors, including hormone-dependent signaling, on HR+ breast cancer.

Abstract

Metabolic reprogramming enables cancer cells to adapt to the changing microenvironment in order to maintain metabolic energy and to provide the necessary biological macromolecules required for cell growth and tumor progression. While changes in tumor metabolism have been long recognized as a hallmark of cancer, recent advances have begun to delineate the mechanisms that modulate metabolic pathways and the consequence of altered signaling on tumorigenesis. This is particularly evident in hormone receptor positive (HR+) breast cancers which account for approximately 70% of breast cancer cases. Emerging evidence indicates that HR+ breast tumors are dependent on multiple metabolic processes for tumor progression, metastasis, and therapeutic resistance and that changes in metabolic programs are driven, in part, by a number of key nuclear receptors including hormone-dependent signaling. In this review, we discuss the mechanisms and impact of hormone receptor mediated metabolic reprogramming on HR+ breast cancer genesis and progression as well as the therapeutic implications of these metabolic processes in this disease.

Construction and Validation of a Nomogram for the Preoperative Prediction of Lymph Node Metastasis in Gastric Cancer

Background:

Increasing evidence indicated that the tumor microenvironment (TME) plays a critical role in tumor progression. This study aimed to identify and evaluate mRNA signature involved in lymph node metastasis (LNM) in TME for gastric cancer (GC).

Methods:

Gene expression and clinical data were downloaded from The Cancer Genome Atlas (TCGA). The ESTIMATE algorithm was used to evaluate the TME of GC. The heatmap and Venn plots were applied for visualizing and screening out intersect differentially expressed genes (DEGs) involved in LNM in TME. Functional enrichment analysis, gene set enrichment analysis (GSEA) and protein-protein interaction (PPI) network were also conducted. Furthermore, binary logistic regression analysis were employed to develop a 4-mRNAs signature for the LNM prediction. ROC curves were applied to validate the LNM predictive ability of the riskscore. Nomogram was constructed and calibration curve was plotted to verify the predictive power of nomogram.

Results:

A total of 88 LNM related DEGs were identified. Functional enrichment analysis and GSEA implied that those genes were associated with some biological processes, such as ion transportation, lipid metabolism and thiolester hydrolase activity. After univariate and multivariate logistic regression analysis, 4 mRNAs (RASSF2, MS4A2, ANKRD33B and ADH1B) were eventually screened out to develop a predictive model. ROC curves manifested the good performance of the 4-mRNAs signature. The proportion of patients with LNM in high-risk group was significantly higher than that in low-risk group. The C-index of nomogram from training and test cohorts were 0.865 and 0.765, and the nomogram was well calibrated.

Conclusions:

In general, we identified a 4-mRNAs signature that effectively predicted LNM in GC patients. Moreover, the 4-mRNAs signature and nomogram provide a guidance for the preoperative evaluation and postoperative treatment of GC patients.

GEO data mining and TCGA analysis reveal altered branched chain amino acid metabolism in pancreatic cancer patients

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive tumor of the digestive system which has a less than 1% 5-year survival rate. The pathogenesis of PDAC development is incompletely understood. Genetic predisposition, disease history of chronic pancreatitis and diabetes elevate the risk of PDAC while environmental and dietary factors including smoking, alcohol abuse, high fat/protein intake as well as air pollution exacerbate PDAC progression. BCAAs, consisting of leucine, isoleucine and valine are essential amino acids that are obtained from food and play versatile roles in carcinogenesis. Recent studies have demonstrated that BCAA metabolism affects PDAC development but the results are controversial. To explore the possible engagement of BCAA metabolism in PDAC, we took advantage of the GEO and TCGA database and discovered that BCAA uptake is closely related to PDAC development while BCAA catabolism is down-regulated in PDAC tissue. Besides, NOTCH and MYC are differentially involved in BCAA metabolism in tumor and muscle, and enhanced lipid synthesis is independent of BCAA catabolism. Altogether, we highlight BCAA uptake as a promising target for PDAC treatment.

Altered Levels of Desaturation and ω-6 Fatty Acids in Breast Cancer Patients' Red Blood Cell Membranes

Red blood cell (RBC) membrane can reflect fatty acid (FA) contribution from diet and biosynthesis. In cancer, membrane FAs are involved in tumorigenesis and invasiveness, and are indicated as biomarkers to monitor the disease evolution as well as potential targets for therapies and nutritional strategies. The present study provides RBC membrane FA profiles in recently diagnosed breast cancer patients before starting chemotherapy treatment. Patients and controls were recruited, and their dietary habits were collected. FA lipidomic analysis of mature erythrocyte membrane phospholipids in blood samples was performed. Data were adjusted to correct for the effects of diet, body mass index (BMI), and age, revealing that patients showed lower levels of saturated fatty acids (SFA) and higher levels of monounsaturated fatty acid, cis-vaccenic (25%) than controls, with consequent differences in desaturase enzymatic index (∆9 desaturase, -13.1%). In the case of polyunsaturated fatty acids (PUFA), patients had higher values of ω-6 FA (C18:2 (+11.1%); C20:4 (+7.4%)). RBC membrane lipidomic analysis in breast cancer revealed that ω-6 pathways are favored. These results suggest new potential targets for treatments and better nutritional guidelines.

The Function and Mechanism of Lipid Molecules and Their Roles in The Diagnosis and Prognosis of Breast Cancer

Lipids are essential components of cell structure and play important roles in signal transduction between cells and body metabolism. With the continuous development and innovation of lipidomics technology, many studies have shown that the relationship between lipids and cancer is steadily increasing, involving cancer occurrence, proliferation, migration, and apoptosis. Breast cancer has seriously affected the safety and quality of life of human beings worldwide and has become a significant public health problem in modern society, with an especially high incidence among women. Therefore, the issue has inspired scientific researchers to study the link between lipids and breast cancer. This article reviews the research progress of lipidomics, the biological characteristics of lipid molecules, and the relationship between some lipids and cancer drug resistance. Furthermore, this work summarizes the lipid molecules related to breast cancer diagnosis and prognosis, and then it clarifies their impact on the occurrence and development of breast cancer The discussion revolves around the current research hotspot long-chain non-coding RNAs (lncRNAs), summarizes and explains their impact on tumor lipid metabolism, and provides more scientific basis for future cancer research studies.