Cancer cells incorporate and remodel exogenous palmitate into structural and oncogenic signaling lipids

Elevated levels of total cholesterol and high-density lipoprotein cholesterol are associated with better prognosis in patients with lung adenocarcinoma: a retrospective cohort study

Background

As is well known, lipids play an important role in cellular metabolism and storage, and they have a significant impact on signal transduction during the growth and metastasis of cancer cells. Our study aimed to evaluate the role of the preoperative plasma lipid profile, including triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) in prognosis, and to develop nomograms to predict overall survival (OS) and disease-free survival (DFS) based on the preoperative plasma lipid profile for patients with lung adenocarcinoma (LUAD) after complete resection.

Methods

Clinical data, including preoperative plasma profile levels, were retrospectively collected and reviewed in 304 patients with LUAD who underwent radical lung resection between 2016-2017. Approval of the study protocol was obtained from the Academic Ethics Committee of Shaoxing People's Hospital, and follow-up on all patients was completed in the clinic or by telephone. The OS and DFS were assessed by the Kaplan-Meier method and the Cox proportional hazards regression model. Clinicopathological factors and preoperative plasma lipid profile factors were integrated to construct nomograms. Calibration plots and concordance indexes (C-indexes) were used to evaluate the accuracy and discrimination of the models.

Results

TC level was significantly related to the sex of the patient (P=0.001), history of smoking (P=0.04), and death (P=0.007), and the HDL-C level was significantly associated with sex (P=0.004), history of smoking (P=0.02), tumor recurrence (P=0.050), and death (P=0.002). TC ≤3.58 and HDL-C ≤1.01 were deemed as independent preoperative risk factors for OS, and HDL-C ≤1.01 was an independent preoperative risk factor for DFS. In the multivariate analyses involving OS and DFS, an increased TC level [hazard ratio (HR), 0.504; 95% confidence interval (CI): 0.324-0.782, P=0.002] was significantly associated with better OS. Additionally, a decreased HDL-C level was significantly associated with worse OS (HR, 0.665; 95% CI: 0.443-0.999, P=0.049) and DFS (HR, 0.619; 95% CI: 0.420-0.912, P=0.02). Preoperative plasma lipid profile factors were involved in constructing the nomograms for predicting 1-, 3-, and 5-year OS and DFS. The C-index of the final nomograms was higher than that of the tumor node metastasis (TNM) staging system for predicting OS (0.735 vs. 0.689; P=0.009). The performance of the nomograms for predicting OS (0.699 vs. 0.735; P=0.03) and DFS (0.659 vs. 0.700; P=0.002) was significantly lower when preoperative plasma lipid profile factors were excluded. These findings indicated that TC and HDL-C levels are associated with the prognosis in patients with LUAD.

Conclusions

In patients with LUAD, increased TC levels may predict better OS, while decreased levels of HDL-C may predict worse outcomes for both DFS and OS. These findings may aid in the identification of high-risk patients and allow them to take necessary measures in advance.

Metabolomics approach using HR-MAS NMR spectroscopy for the assessment of metabolic profiles of uterine fibroids

The aim of this study is to determine dysregulated metabolites and metabolic pathways in uterine fibroids and in the myometrial tissue from which uterine fibroids are derived. Fifteen (15) patients underwent hysterectomy because of uterine fibroids and 14 controls were included in this study. 1H HR-MAS NMR spectroscopy data were obtained from uterine fibroid tissue, the adjacent healthy myometrial tissue from cases, and myometrial tissue from controls. PCA and PLS-DA score plots from multivariate statistical analysis of pre-processed spectral data demonstrated a distinction between cases and control groups. The levels of lactate, alanine, glutamate, glutamine, methionine, acetone, isocitrate, choline, glycerophosphocholine, phosphocholine, o-phosphoethanolamine, taurine, myo-inositol, p-methylhistidine, phenylacetate, ascorbate, glucose, and methylhistidine were significantly higher in uterine fibroid tissue compared to the neighboring healthy myometrial tissue. Additionally, when adjacent healthy myometrial tissue was compared to control myometrial tissue, significantly lower levels of valine, leucine, isoleucine, ethanol, arginine, N-acetyl tyrosine, acetone, p-methylhistidine, glucose, phenylacetate, myo-inositol, and alpha-glucose were observed. The study provides a foundational framework by revealing the metabolomic heterogeneity of uterine fibroids. Strategies should be developed to target the metabolic alterations that contribute to the growth of these common tumors.

Lipids in Clinical Nutrition and Health: Narrative Review and Dietary Recommendations

Lipids are essential components of human health, serving as critical structural elements of cell membranes, energy sources, and precursors for bioactive molecules. This narrative review aims to examine the multifaceted roles of lipids in clinical nutrition and health, focusing on their impact on chronic disease prevention, management, and the potential of lipid-based therapies. A narrative review was conducted utilizing Scopus, Google Scholar, and Web of Science databases. Key terms such as lipids, dietary fats, and cholesterol were used to identify and analyze relevant studies. A total of 145 articles meeting inclusion criteria were reviewed for their insights into lipid metabolism, dietary sources, and clinical implications. The analysis highlighted the metabolic significance of various lipid classes-saturated, monounsaturated, and polyunsaturated fatty acids-along with evidence-based recommendations for their dietary intake. Lipids were shown to play a pivotal role in managing chronic diseases such as cardiovascular disease, obesity, and metabolic syndrome. Emerging therapies, including omega-3 fatty acids and medium-chain triglycerides, demonstrated potential benefits in clinical practice. By synthesizing current knowledge, this narrative review provides healthcare professionals with an updated understanding of the roles of lipids in clinical nutrition. The findings emphasize the importance of tailored dietary interventions and lipid-based therapies in optimizing health and managing chronic diseases effectively. Additionally, this review successfully presents practical dietary recommendations to guide clinical practice.

Cell Membrane Fatty Acids and PIPs Modulate the Etiology of Pancreatic Cancer by Regulating AKT

Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the worst solid malignancies in regard to outcomes and metabolic dysfunction leading to cachexia. It is alarming that PDAC incidence rates continue to increase and warrant the need for innovative approaches to combat this disease. Due to its relatively slow progression (10-20 years), prevention strategies represent an effective means to improve outcomes. One of the risk factors for many cancers and for pancreatic cancer in particular is diet. Hence, our objective is to understand how a diet rich in ω3 and ω6 polyunsaturated fatty acids affects the progression of this disease. Methods: We investigated polyunsaturated fatty acid (PUFA) effects on disease progression employing both in vitro (PDAC cell lines) and in vivo (EL-Kras and KC mice) approaches. Also, we gathered data from the National Health and Nutrition Examination Survey (NHANES) and the National Cancer Institute (NCI) from 1999 to 2017 for a retrospective observational study. Results: The consumption of PUFAs in a patient population correlates with increased PDAC incidence, particularly when the ω3 intake increases to a lesser extent than ω6. Our data demonstrate dietary PUFAs can be incorporated into plasma membrane lipids affecting PI3K/AKT signaling and support the emergence of membrane-targeted therapies. Moreover, we show that the phospholipid composition of a lipid nanoparticle (LNP) can impact the cell membrane integrity and, ultimately, cell viability after administration of these LNPs. Conclusions: Cancer prevention is impactful particularly for those with very poor prognosis, including pancreatic cancer. Our results point to the importance of dietary intervention in this disease when detected early and the potential to improve the antiproliferative effect of drug efficacy when combined with these regimens in later stages of pancreatic cancer.

Metabolomics and miRNA profiling reveals feature of gallbladder cancer-derived biliary extracellular vesicles

BACKGROUND

Although there are several studies in the development of various human cancers, the role of exosomes is poorly understood in the progression of gallbladder cancer. This study aims to characterize the metabolic changes occurring in exosomes obtained from patients with gallbladder cancer compared with those from other gallbladder disease groups.

METHODS

Biliary exosomes were isolated from healthy donors (n = 3) and from patients with gallbladder cancer (n = 3), gallbladder polyps (n = 4), or cholecystitis (n = 3) using a validated exosome isolation kit. Afterward, we performed miRNA profiling and untargeted metabolomic analysis of the exosomes. The results were validated by integrating the results of the miRNA and metabolomic analyses.

RESULTS

The gallbladder cancer group exhibited a significant reduction in the levels of multiple unsaturated phosphatidylethanolamines and phosphatidylcholines compared to the normal group, which resulted in the loss of exosome membrane integrity. Additionally, the gallbladder cancer group demonstrated significant overexpression of miR-181c and palmitic acid, and decreased levels of conjugated deoxycholic acid, all of which are strongly associated with the activation of the PI3K/AKT pathway.

CONCLUSIONS

Our findings demonstrate that the contents of exosomes are disease-specific, particularly in gallbladder cancer, and that altered metabolites convey critical information regarding their phenotype. We believe that our metabolomic and miRNA profiling results may provide important insights into the development of gallbladder cancer.

Spatial heterogeneity of peri-tumoural lipid composition in postmenopausal patients with oestrogen receptor positive breast cancer

Deregulation of lipid composition in adipose tissue adjacent to breast tumour is observed in ex vivo and animal models. Novel non-invasive magnetic resonance imaging (MRI) allows rapid lipid mapping of the human whole breast. We set out to elucidate the spatial heterogeneity of peri-tumoural lipid composition in postmenopausal patients with oestrogen receptor positive (ER +) breast cancer. Thirteen participants (mean age, 62 ± [SD] 6 years) with ER + breast cancer and 13 age-matched postmenopausal healthy controls were scanned on MRI. The number of double bonds in triglycerides was computed from MRI images to derive lipid composition maps of monounsaturated, polyunsaturated, and saturated fatty acids (MUFA, PUFA, SFA). The spatial heterogeneity measures (mean, median, skewness, entropy and kurtosis) of lipid composition in the peri-tumoural region and the whole breast of participants and in the whole breast of controls were computed. The Ki-67 proliferative activity marker and CD163 antibody on tumour-associated macrophages were assessed histologically. Mann Whitney U or Wilcoxon tests and Spearman's coefficients were used to assess group differences and correlations, respectively. For comparison against the whole breast in participants, peri-tumoural MUFA had a lower mean (median (IQR), 0.40 (0.02), p < .001), lower median (0.42 (0.02), p < .001), a negative skewness with lower magnitude (- 1.65 (0.77), p = .001), higher entropy (4.35 (0.64), p = .007) and lower kurtosis (5.13 (3.99), p = .001). Peri-tumoural PUFA had a lower mean (p < .001), lower median (p < .001), a positive skewness with higher magnitude (p = .005) and lower entropy (p = .002). Peri-tumoural SFA had a higher mean (p < .001), higher median (p < .001), a positive skewness with lower magnitude (p < .001) and lower entropy (p = .012). For comparison against the whole breast in controls, peri-tumoural MUFA had a negative skewness with lower magnitude (p = .01) and lower kurtosis (p = .009), however there was no difference in PUFA or SFA. CD163 moderately correlated with peri-tumoural MUFA skewness (rs = - .64), PUFA entropy (rs = .63) and SFA skewness (rs = .59). There was a lower MUFA and PUFA while a higher SFA, and a higher heterogeneity of MUFA while a lower heterogeneity of PUFA and SFA, in the peri-tumoural region in comparison with the whole breast tissue. The degree of lipid deregulation was associated with inflammation as indicated by CD163 antibody on macrophages, serving as potential marker for early diagnosis and response to therapy.

Circadian clock and lipid metabolism disorders: a potential therapeutic strategy for cancer

Recent research has emphasized the interaction between the circadian clock and lipid metabolism, particularly in relation to tumors. This review aims to explore how the circadian clock regulates lipid metabolism and its impact on carcinogenesis. Specifically, targeting key enzymes involved in fatty acid synthesis (SREBP, ACLY, ACC, FASN, and SCD) has been identified as a potential strategy for cancer therapy. By disrupting these enzymes, it may be possible to inhibit tumor growth by interfering with lipid metabolism. Transcription factors, like SREBP play a significant role in regulating fatty acid synthesis which is influenced by circadian clock genes such as BMAL1, REV-ERB and DEC. This suggests a strong connection between fatty acid synthesis and the circadian clock. Therefore, successful combination therapy should target fatty acid synthesis in addition to considering the timing and duration of drug use. Ultimately, personalized chronotherapy can enhance drug efficacy in cancer treatment and achieve treatment goals.

Metabolic Patterns of High-Invasive and Low-Invasive Oral Squamous Cell Carcinoma Cells Using Quantitative Metabolomics and 13C-Glucose Tracing

Most current metabolomics studies of oral squamous cell carcinoma (OSCC) are mainly focused on identifying potential biomarkers for early screening and diagnosis, while few studies have investigated the metabolic profiles promoting metastasis. In this study, we aimed to explore the altered metabolic pathways associated with metastasis of OSCC. Here, we identified four OSCC cell models (CAL27, HN6, HSC-3, SAS) that possess different invasive heterogeneity via the transwell invasion assay and divided them into high-invasive (HN6, SAS) and low-invasive (CAL27, HSC-3) cells. Quantitative analysis and stable isotope tracing using [U-13C6] glucose were performed to detect the altered metabolites in high-invasive OSCC cells, low-invasive OSCC cells and normal human oral keratinocytes (HOK). The metabolic changes in the high-invasive and low-invasive cells included elevated glycolysis, increased fatty acid metabolism and an impaired TCA cycle compared with HOK. Moreover, pathway analysis demonstrated significant differences in fatty acid biosynthesis; arachidonic acid (AA) metabolism; and glycine, serine and threonine metabolism between the high-invasive and low-invasive cells. Furthermore, the high-invasive cells displayed a significant increase in the percentages of 13C-glycine, 13C-palmitate, 13C-stearic acid, 13C-oleic acid, 13C-AA and estimated FADS1/2 activities compared with the low-invasive cells. Overall, this exploratory study suggested that the metabolic differences related to the metastatic phenotypes of OSCC cells were concentrated in glycine metabolism, de novo fatty acid synthesis and polyunsaturated fatty acid (PUFA) metabolism, providing a comprehensive understanding of the metabolic alterations and a basis for studying related molecular mechanisms in metastatic OSCC cells.

Metabolic labelling of a subpopulation of small extracellular vesicles using a fluorescent palmitic acid analogue

Exosomes are among the most puzzling vehicles of intercellular communication, but several crucial aspects of their biogenesis remain elusive, primarily due to the difficulty in purifying vesicles with similar sizes and densities. Here we report an effective methodology for labelling small extracellular vesicles (sEV) using Bodipy FL C16, a fluorescent palmitic acid analogue. In this study, we present compelling evidence that the fluorescent sEV population derived from Bodipy C16-labelled cells represents a discrete subpopulation of small exosomes following an intracellular pathway. Rapid cellular uptake and metabolism of Bodipy C16 resulted in the incorporation of fluorescent phospholipids into intracellular organelles specifically excluding the plasma membrane and ultimately becoming part of the exosomal membrane. Importantly, our fluorescence labelling method facilitated accurate quantification and characterization of exosomes, overcoming the limitations of nonspecific dye incorporation into heterogeneous vesicle populations. The characterization of Bodipy-labelled exosomes reveals their enrichment in tetraspanin markers, particularly CD63 and CD81, and in minor proportion CD9. Moreover, we employed nanoFACS sorting and electron microscopy to confirm the exosomal nature of Bodipy-labelled vesicles. This innovative metabolic labelling approach, based on the fate of a fatty acid, offers new avenues for investigating exosome biogenesis and functional properties in various physiological and pathological contexts.

Obesity and prostate cancer - microenvironmental roles of adipose tissue

Obesity is known to have important roles in driving prostate cancer aggressiveness and increased mortality. Multiple mechanisms have been postulated for these clinical observations, including effects of diet and lifestyle, systemic changes in energy balance and hormonal regulation and activation of signalling by growth factors and cytokines and other components of the immune system. Over the past decade, research on obesity has shifted towards investigating the role of peri-prostatic white adipose tissue as an important source of locally produced factors that stimulate prostate cancer progression. Cells that comprise white adipose tissue, the adipocytes and their progenitor adipose stromal cells (ASCs), which proliferate to accommodate white adipose tissue expansion in obesity, have been identified as important drivers of obesity-associated cancer progression. Accumulating evidence suggests that adipocytes are a source of lipids that are used by adjacent prostate cancer cells. However, results of preclinical studies indicate that ASCs promote tumour growth by remodelling extracellular matrix and supporting neovascularization, contributing to the recruitment of immunosuppressive cells, and inducing epithelial-mesenchymal transition through paracrine signalling. Because epithelial-mesenchymal transition is associated with cancer chemotherapy resistance and metastasis, ASCs are considered to be potential targets of therapies that could be developed to suppress cancer aggressiveness in patients with obesity.

Tracking the Metabolic Fate of Exogenous Arachidonic Acid in Ferroptosis Using Dual-Isotope Labeling Lipidomics

Lipid metabolism is implicated in a variety of diseases, including cancer, cell death, and inflammation, but lipidomics has proven to be challenging due to the vast structural diversity over a narrow range of mass and polarity of lipids. Isotope labeling is often used in metabolomics studies to follow the metabolism of exogenously added labeled compounds because they can be differentiated from endogenous compounds by the mass shift associated with the label. The application of isotope labeling to lipidomics has also been explored as a method to track the metabolism of lipids in various disease states. However, it can be difficult to differentiate a single isotopically labeled lipid from the rest of the lipidome due to the variety of endogenous lipids present over the same mass range. Here we report the development of a dual-isotope deuterium labeling method to track the metabolic fate of exogenous polyunsaturated fatty acids, e.g., arachidonic acid, in the context of ferroptosis using hydrophilic interaction-ion mobility-mass spectrometry (HILIC-IM-MS). Ferroptosis is a type of cell death that is dependent on lipid peroxidation. The use of two isotope labels rather than one enables the identification of labeled species by a signature doublet peak in the resulting mass spectra. A Python-based software, D-Tracer, was developed to efficiently extract metabolites with dual-isotope labels. The labeled species were then identified with LiPydomics based on their retention times, collision cross section, and m/z values. Changes in exogenous AA incorporation in the absence and presence of a ferroptosis inducer were elucidated.

Using mass spectrometry imaging to map fluxes quantitatively in the tumor ecosystem

Tumors are comprised of a multitude of cell types spanning different microenvironments. Mass spectrometry imaging (MSI) has the potential to identify metabolic patterns within the tumor ecosystem and surrounding tissues, but conventional workflows have not yet fully integrated the breadth of experimental techniques in metabolomics. Here, we combine MSI, stable isotope labeling, and a spatial variant of Isotopologue Spectral Analysis to map distributions of metabolite abundances, nutrient contributions, and metabolic turnover fluxes across the brains of mice harboring GL261 glioma, a widely used model for glioblastoma. When integrated with MSI, the combination of ion mobility, desorption electrospray ionization, and matrix assisted laser desorption ionization reveals alterations in multiple anabolic pathways. De novo fatty acid synthesis flux is increased by approximately 3-fold in glioma relative to surrounding healthy tissue. Fatty acid elongation flux is elevated even higher at 8-fold relative to surrounding healthy tissue and highlights the importance of elongase activity in glioma.

The Activation of PPARγ by (2Z,4E,6E)-2-methoxyocta-2,4,6-trienoic Acid Counteracts the Epithelial–Mesenchymal Transition Process in Skin Carcinogenesis

Cutaneous squamous cell carcinoma (cSCC) is the most common UV-induced keratinocyte-derived cancer, and its progression is characterized by the epithelial–mesenchymal transition (EMT) process. We previously demonstrated that PPARγ activation by 2,4,6-octatrienoic acid (Octa) prevents cutaneous UV damage. We investigated the possible role of the PPARγ activators Octa and the new compound (2Z,4E,6E)-2-methoxyocta-2,4,6-trienoic acid (A02) in targeting keratinocyte-derived skin cancer. Like Octa, A02 exerted a protective effect against UVB-induced oxidative stress and DNA damage in NHKs. In the squamous cell carcinoma A431 cells, A02 inhibited cell proliferation and increased differentiation markers’ expression. Moreover, Octa and even more A02 counteracted the TGF-β1-dependent increase in mesenchymal markers, intracellular ROS, the activation of EMT-related signal transduction pathways, and cells’ migratory capacity. Both compounds, especially A02, counterbalanced the TGF-β1-induced cell membrane lipid remodeling and the release of bioactive lipids involved in EMT. In vivo experiments on a murine model useful to study cell proliferation in adult animals showed the reduction of areas characterized by active cell proliferation in response to A02 topical treatment. In conclusion, targeting PPARγ may be useful for the prevention and treatment of keratinocyte-derived skin cancer.

Flavonoids attenuate cancer metabolism by modulating Lipid metabolism, amino acids, ketone bodies and redox state mediated by Nrf2

Metabolic reprogramming of cancer cells is a common hallmark of malignant transformation. The preference for aerobic glycolysis over oxidative phosphorylation in tumors is a well-studied phenomenon known as the Warburg effect. Importantly, metabolic transformation of cancer cells also involves alterations in signaling cascades contributing to lipid metabolism, amino acid flux and synthesis, and utilization of ketone bodies. Also, redox regulation interacts with metabolic reprogramming during malignant transformation. Flavonoids, widely distributed phytochemicals in plants, exert various beneficial effects on human health through modulating molecular cascades altered in the pathological cancer phenotype. Recent evidence has identified numerous flavonoids as modulators of critical components of cancer metabolism and associated pathways interacting with metabolic cascades such as redox balance. Flavonoids affect lipid metabolism by regulating fatty acid synthase, redox balance by modulating nuclear factor-erythroid factor 2-related factor 2 (Nrf2) activity, or amino acid flux and synthesis by phosphoglycerate mutase 1. Here, we discuss recent preclinical evidence evaluating the impact of flavonoids on cancer metabolism, focusing on lipid and amino acid metabolic cascades, redox balance, and ketone bodies.

Isolation and characterization of N-(2-Hydroxyethyl)hexadecanamide from Colletotrichum gloeosporioides with apoptosis-inducing potential in breast cancer cells

Endophytic fungi are a well-established reservoir of bioactive compounds that are pharmaceutically valuable and therefore, contribute significantly to the biomedical field. The present study aims to identify the bioactive anticancer compound from ethyl acetate extract of fungal endophyte, Colletotrichum gloeosporioides associated with the leaf of the medicinal plant Oroxylum indicum. The fatty acid amide compound N-(2-Hydroxyethyl)hexadecanamide (Palmitoylethanolamide; PEA) was identified using antioxidant activity-guided fractionation assisted with tandem liquid chromatography coupled with quadrupole time of flight mass spectrometry, Fourier transform-infrared spectroscopy, time-of-flight mass spectrometry, and nuclear magnetic resonance. In-Silico molecular docking analysis showed that PEA potentially docked to the active sites of apoptosis-inducing proteins including BAX, BCL-2, P21, and P53. Further validation was done using in vitro study that showed PEA inhibitsthe proliferation, alters nuclear morphology and attenuates the wound closure ability of MDA-MB-231 and MCF-7 cells. PEA induces apoptosis via upregulating cell-cycle arrest (P21), tumor suppression (P53), pro-apoptotic (BAX, CASPASE-8, and FADD) genes, and downregulating anti-apoptotic gene BCL-2. The upregulation of the active form of Caspase-3 was also reported. This is the first-ever report for the isolation of PEA from C. gloeosporioides with anticancer activity against human breast cancer cells and therefore holds great potential for future therapeutics.

Effective breast cancer therapy based on palmitic acid-loaded PLGA nanoparticles

Although new strategies for breast cancer treatment have yielded promising results, most drugs can lead to serious side effects when applied systemically. Doxorubicin (DOX), currently the most effective chemotherapeutic drug to treat breast cancer, is poorly selective towards tumor cells and treatment often leads to the development of drug resistance. Recent studies have indicated that several fatty acids (FAs) have beneficial effects on inhibiting tumorigenesis. The saturated FA palmitic acid (PA) showed anti-tumor activities in several types of cancer, as well as effective repolarization of M2 macrophages towards the anti-tumorigenic M1 phenotype. However, water insolubility and cellular impermeability limit the use of PA in vivo. To overcome these limitations, here, we encapsulated PA into a poly(d,l-lactic co-glycolic acid) (PLGA) nanoparticle (NP) platform, alone and in combination with DOX, to explore PA's potential as mono or combinational breast cancer therapy. Our results showed that PLGA-PA-DOX NPs and PLGA-PA NPs significantly reduced the viability and migratory capacity of breast cancer cells in vitro. In vivo studies in mice bearing mammary tumors demonstrated that PLGA-PA-NPs were as effective in reducing primary tumor growth and metastasis as NPs loaded with DOX, PA and DOX, or free DOX. At the molecular level, PLGA-PA NPs reduced the expression of genes associated with multi-drug resistance and inhibition of apoptosis, and induced apoptosis via a caspase-3-independent pathway in breast cancer cells. In addition, immunohistochemical analysis of residual tumors showed a reduction in M2 macrophage content and infiltration of leukocytes after treatment of PLGA-PA NPs and PLGA-PA-DOX NPs, suggesting immunomodulatory properties of PA in the tumor microenvironment. In conclusion, the use of PA alone or in combination with DOX may represent a promising novel strategy for the treatment of breast cancer.

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.

De novo sphingolipid biosynthesis necessitates detoxification in cancer cells

Sphingolipids play important signaling and structural roles in cells. Here, we find that during de novo sphingolipid biosynthesis, a toxic metabolite is formed with critical implications for cancer cell survival. The enzyme catalyzing the first step in this pathway, serine palmitoyltransferase complex (SPT), is upregulated in breast and other cancers. SPT is dispensable for cancer cell proliferation, as sphingolipids can be salvaged from the environment. However, SPT activity introduces a liability as its product, 3-ketodihydrosphingosine (3KDS), is toxic and requires clearance via the downstream enzyme 3-ketodihydrosphingosine reductase (KDSR). In cancer cells, but not normal cells, targeting KDSR induces toxic 3KDS accumulation leading to endoplasmic reticulum (ER) dysfunction and loss of proteostasis. Furthermore, the antitumor effect of KDSR disruption can be enhanced by increasing metabolic input (via high-fat diet) to allow greater 3KDS production. Thus, de novo sphingolipid biosynthesis entails a detoxification requirement in cancer cells that can be therapeutically exploited.

PTPRO represses colorectal cancer tumorigenesis and progression by reprogramming fatty acid metabolism

BACKGROUND

Abnormal expression of protein tyrosine phosphatases (PTPs) has been reported to be a crucial cause of cancer. As a member of PTPs, protein tyrosine phosphatase receptor type O (PTPRO) has been revealed to play tumor suppressive roles in several cancers, while its roles in colorectal cancer (CRC) remains to be elucidated. Hence, we aimed to explore the roles and mechanisms of PTPRO in CRC initiation and progression.

METHODS

The influences of PTPRO on the growth and liver metastasis of CRC cells and the expression patterns of different lipid metabolism enzymes were evaluated in vitro and in vivo. Molecular and biological experiments were conducted to uncover the underpinning mechanisms of dysregulated de novo lipogenesis and fatty acid β-oxidation.

RESULTS

PTPRO expression was notably downregulated in CRC liver metastasis compared to the primary cancer, and such a downregulation was associated with poor prognosis of patients with CRC. PTPRO silencing significantly promoted cell growth and liver metastasis. Compared with PTPRO wild-type mice, PTPRO-knockout mice developed more tumors and harbored larger tumor loads under treatment with azoxymethane and dextran sulfate sodium. Gene set enrichment analysis revealed that PTPRO downregulation was significantly associated with the fatty acid metabolism pathways. Blockage of fatty acid synthesis abrogated the effects of PTPRO silencing on cell growth and liver metastasis. Further experiments indicated that PTPRO silencing induced the activation of the AKT serine/threonine kinase (AKT)/mammalian target of rapamycin (mTOR) signaling axis, thus promoting de novo lipogenesis by enhancing the expression of sterol regulatory element-binding protein 1 (SREBP1) and its target lipogenic enzyme acetyl-CoA carboxylase alpha (ACC1) by activating the AKT/mTOR signaling pathway. Furthermore, PTPRO attenuation decreased the fatty acid oxidation rate by repressing the expression of peroxisome proliferator-activated receptor alpha (PPARα) and its downstream enzyme peroxisomal acyl-coenzyme A oxidase 1 (ACOX1) via activating the p38/extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) signaling pathway.

CONCLUSIONS

PTPRO could suppress CRC development and metastasis via modulating the AKT/mTOR/SREBP1/ACC1 and MAPK/PPARα/ACOX1 pathways and reprogramming lipid metabolism.

The lipidomic profile of the tumoral periprostatic adipose tissue reveals alterations in tumor cell's metabolic crosstalk

BACKGROUND

Periprostatic adipose tissue (PPAT) plays a role in prostate cancer (PCa) progression. PPAT lipidomic composition study may allow us to understand the tumor metabolic microenvironment and provide new stratification factors.

METHODS

We used ultra-high-performance liquid chromatography-mass spectrometry-based non-targeted lipidomics to profile lipids in the PPAT of 40 patients with PCa (n = 20 with low-risk and n = 20 high-risk). Partial least squares-discriminant analysis (PLS-DA) and variable importance in projection (VIP) analysis were used to identify the most relevant features of PPAT between low- and high-risk PCa, and metabolite set enrichment analysis was used to detect disrupted metabolic pathways. Metabolic crosstalk between PPAT and PCa cell lines (PC-3 and LNCaP) was studied using ex vivo experiments. Lipid uptake and lipid accumulation were measured. Lipid metabolic-related genes (SREBP1, FASN, ACACA, LIPE, PPARG, CD36, PNPLA2, FABP4, CPT1A, FATP5, ADIPOQ), inflammatory markers (IL-6, IL-1B, TNFα), and tumor-related markers (ESRRA, MMP-9, TWIST1) were measured by RT-qPCR.

RESULTS

Significant differences in the content of 67 lipid species were identified in PPAT samples between high- and low-risk PCa. PLS-DA and VIP analyses revealed a discriminating lipidomic panel between low- and high-risk PCa, suggesting the occurrence of disordered lipid metabolism in patients related to PCa aggressiveness. Functional analysis revealed that alterations in fatty acid biosynthesis, linoleic acid metabolism, and β-oxidation of very long-chain fatty acids had the greatest impact in the PPAT lipidome. Gene analyses of PPAT samples demonstrated that the expression of genes associated with de novo fatty acid synthesis such as FASN and ACACA were significantly lower in PPAT from high-risk PCa than in low-risk counterparts. This was accompanied by the overexpression of inflammatory markers (IL-6, IL-1B, and TNFα). Co-culture of PPAT explants with PCa cell lines revealed a reduced gene expression of lipid metabolic-related genes (CD36, FASN, PPARG, and CPT1A), contrary to that observed in co-cultured PCa cell lines. This was followed by an increase in lipid uptake and lipid accumulation in PCa cells. Tumor-related genes were increased in co-cultured PCa cell lines.

CONCLUSIONS

Disturbances in PPAT lipid metabolism of patients with high-risk PCa are associated with tumor cell metabolic changes.

Higher genetically predicted low-density lipoprotein levels increase the renal cancer risk independent of triglycerides and high-density lipoprotein levels: A Mendelian randomization study

The causation between lipids and renal cancer remains inconclusive. Our purpose is to explore the causal relationships between the three primary lipid metabolism-related substances, namely triglycerides (TG), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) with the risk of renal cancer using Mendelian randomization (MR) methods. Genetic instruments for lipids were acquired from the UK Biobank. Outcome data were from the FinnGen study (1397 renal cancer cases and 204 070). Single-variable MR (SVMR) and multi-variable MR (MVMR) analyses were conducted with TwoSampleMR package based on R 4.0.3. The random-effect inverse-variance weighted (IVW), MR-Egger, weighted-median method, and weighted mode were the four main computing methods. We found that per 1 SD elevated LDL level was causally associated with renal cancer occurrence based on SVMR (OR, 1.31, 95% CI: 1.05-1.64, P = .016). Similar significant associations were found in other methods. However, the results of SVMR did not support significant associations between TG, and HDL with renal cancer risk in all methods. The association between LDL and renal cancer was still significant in MVMR analysis (OR for IVW method: 1.22 per 1 SD higher trait (SD, 95% CI: 1.11-1.34, P < .001; OR for MR-Egger: 1.22 per 1 SD higher trait, 95% CI: 1.01-1.47, P = .042) when taking TG and HDL into consideration. Our study supported that elevated serum LDL levels is causally associated with an increased risk of renal cancer independent of TG and HDL.

The adipocyte microenvironment and cancer

Many epithelial tumors grow in the vicinity of or metastasize to adipose tissue. As tumors develop, crosstalk between adipose tissue and cancer cells leads to changes in adipocyte function and paracrine signaling, promoting a microenvironment that supports tumor growth. Over the last decade, it became clear that tumor cells co-opt adipocytes in the tumor microenvironment, converting them into cancer-associated adipocytes (CAA). As adipocytes and cancer cells engage, a metabolic symbiosis ensues that is driven by bi-directional signaling. Many cancers (colon, breast, prostate, lung, ovarian cancer, and hematologic malignancies) stimulate lipolysis in adipocytes, followed by the uptake of fatty acids (FA) from the surrounding adipose tissue. The FA enters the cancer cell through specific fatty acid receptors and binding proteins (e.g., CD36, FATP1) and are used for membrane synthesis, energy metabolism (β-oxidation), or lipid-derived cell signaling molecules (derivatives of arachidonic and linolenic acid). Therefore, blocking adipocyte-derived lipid uptake or lipid-associated metabolic pathways in cancer cells, either with a single agent or in combination with standard of care chemotherapy, might prove to be an effective strategy against cancers that grow in lipid-rich tumor microenvironments.

Connecting Metabolic Rewiring With Phenotype Switching in Melanoma

Melanoma is a complex and aggressive cancer type that contains different cell subpopulations displaying distinct phenotypes within the same tumor. Metabolic reprogramming, a hallmark of cell transformation, is essential for melanoma cells to adopt different phenotypic states necessary for adaptation to changes arising from a dynamic milieu and oncogenic mutations. Increasing evidence demonstrates how melanoma cells can exhibit distinct metabolic profiles depending on their specific phenotype, allowing adaptation to hostile microenvironmental conditions, such as hypoxia or nutrient depletion. For instance, increased glucose consumption and lipid anabolism are associated with proliferation, while a dependency on exogenous fatty acids and an oxidative state are linked to invasion and metastatic dissemination. How these different metabolic dependencies are integrated with specific cell phenotypes is poorly understood and little is known about metabolic changes underpinning melanoma metastasis. Recent evidence suggests that metabolic rewiring engaging transitions to invasion and metastatic progression may be dependent on several factors, such as specific oncogenic programs or lineage-restricted mechanisms controlling cell metabolism, intra-tumor microenvironmental cues and anatomical location of metastasis. In this review we highlight how the main molecular events supporting melanoma metabolic rewiring and phenotype-switching are parallel and interconnected events that dictate tumor progression and metastatic dissemination through interplay with the tumor microenvironment.

Characterization of Fatty Acid Metabolism in Lung Adenocarcinoma

Background: Lung adenocarcinoma (LUAD) is the most common subtype of non-small cell lung cancer. Fatty acid metabolism takes part in malignancy progression. However, the roles fatty acid metabolism plays in LUAD are still unclear.

Methods: The transcriptomic and clinical data of LUAD patients from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were extracted. ssGSEA, WGCNA, univariable Cox regression, and LASSO Cox regression analyses were performed to identify the fatty acid metabolism-related genes which influenced the overall survival (OS) and build a fatty acid-related risk score (FARS) model. A nomogram was established based on the FARS and other clinicopathological features, and ROC and calibration plots were used to validate the prediction accuracy. The tumor microenvironment (TME) of patients with high and low FARS was compared.

Results: A total of 38 genes were identified to be independently related to the survival outcome and put into a FARS model. High FARS patients exhibited significantly worse OS. The nomogram included the FARS and pathological stage, and the AUC of the nomogram predicting 1-, 2-, 3-, 4-, and 5-year OS was 0.789, 0.807, 0.798, 0.809, and 0.753, respectively. Calibration plots also indicated good accuracy. Moreover, the samples of the high FARS had higher expression of PDL1.

Conclusion: We constructed a FARS model which could accurately predict the survival outcome of the LUAD patients. The genes of the FARS are related to the tumor microenvironment and patients with high FARS can potentially benefit more from anti-PD1/PDL1 immunotherapy. In addition, the mechanisms of the genes in the FARS affecting prognosis are worthy of further research to develop new gene-targeted drugs.

Grade 4 very severe hypertriglyceridaemia at diagnosis in a child with acute lymphoblastic leukaemia

Dyslipidaemia is seen in nearly all cases of acute lymphoblastic leukaemia (ALL) at diagnosis, with mild hypertriglyceridaemia (HTG) in 61% and reduced high-density lipoprotein in 98% cases. HTG irrespective of severity is due to metabolic derangements associated with tumour cells turnover in haematological malignancies and is generally self-limiting. Very severe HTG with overt lipaemic serum is extremely rare at presentation in ALL. HTG is complicated by thrombosis, osteonecrosis and pancreatitis during induction chemotherapy for ALL with steroids and L-asparginase. A careful monitoring is required during induction chemotherapy in ALL when severe HTG is present at diagnosis. We present a female toddler with ALL, who presented with very severe HTG and grossly lipaemic serum. Her very severe HTG decreased to mildly raised HTG at the end of first week of induction chemotherapy. There was no further complication noticed during induction therapy.

CD147 Mediates 5-Fluorouracil Resistance in Colorectal Cancer by Reprogramming Glycolipid Metabolism

Chemoresistance against 5-fluorouracil (5-FU) is a major issue for colorectal cancer (CRC) patients. Increasing evidence for the roles of CD147 in glycolipid metabolic reprogramming and chemoresistance of tumor cells has emerged in recent years. However, whether CD147 contributes to 5-FU resistance in CRC and the role of abnormal glycolipid metabolism in this process remain poorly understood. We analyzed CD147 expression in primary tumor samples of CRC patients and found that upregulated CD147 correlated with decreased 5-FU chemosensitivity and an unfavorable prognosis of CRC patients. Moreover, in vivo and in vitro experiments confirmed that CD147 regulates glycolipid metabolism through two separate pathways. Mechanistically, CD147 upregulates HIF-1α-mediated glycolysis by activating the PI3K/AKT/mTOR pathway and CD147 also attenuates PPARα-mediated fatty acid oxidation by activation of the MAPK pathway. Most importantly, we found that CD147 confers 5-FU resistance in CRC via these glycolipid metabolic signatures. Our results demonstrated that CD147 is a potential 5-FU resistance biomarker for CRC patients and a candidate therapeutic target to restore 5-FU sensitivity of 5-FU-resistant CRC by remodeling glycolipid metabolism.

Metabolomic Analysis of Plasma from Breast Cancer Patients Using Ultra-High-Performance Liquid Chromatography Coupled with Mass Spectrometry: An Untargeted Study

Breast cancer (BC) is one of the leading causes of cancer mortality in women worldwide, and therefore, novel biomarkers for early disease detection are critically needed. We performed herein an untargeted plasma metabolomic profiling of 55 BC patients and 55 healthy controls (HC) using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS). Pre-processed data revealed 2494 ions in total. Data matrices’ paired t-tests revealed 792 ions (both positive and negative) which presented statistically significant changes (FDR < 0.05) in intensity levels between cases versus controls. Metabolites identified with putative names via MetaboQuest using MS/MS and mass-based approaches included amino acid esters (i.e., N-stearoyl tryptophan, L-arginine ethyl ester), dipeptides (ile-ser, met-his), nitrogenous bases (i.e., uracil derivatives), lipid metabolism-derived molecules (caproleic acid), and exogenous compounds from plants, drugs, or dietary supplements. LASSO regression selected 16 metabolites after several variables (TNM Stage, Grade, smoking status, menopausal status, and race) were adjusted. A predictive conditional logistic regression model on the 16 LASSO selected ions provided a high diagnostic performance with an area-under-the-curve (AUC) value of 0.9729 (95% CI 0.96−0.98) on all 55 samples. This study proves that BC possesses a specific metabolic signature that could be exploited as a novel metabolomics-based approach for BC detection and characterization. Future studies of large-scale cohorts are needed to validate these findings.

Peri-tumoural spatial distribution of lipid composition and tubule formation in breast cancer

BACKGROUND

Response guided treatment in breast cancer is highly desirable, but the effectiveness is only established based on residual cellularity from histopathological analysis after surgery. Tubule formation, a key component of grading score, is directly associated with cellularity, with significant implications on prognosis. Peri-tumoural lipid composition, a potential marker, can be rapidly mapped across the entire breast using novel method of chemical shift-encoded imaging, enabling the quantification of spatial distribution. We hypothesise that peri-tumoural spatial distribution of lipid composition is sensitive to tumour cellular differentiation and proliferative activity.

METHODS

Twenty whole tumour specimens freshly excised from patients with invasive ductal carcinoma (9 Score 2 and 11 Score 3 in tubule formation) were scanned on a 3 T clinical scanner (Achieva TX, Philips Healthcare). Quantitative lipid composition maps were acquired for polyunsaturated, monounsaturated, and saturated fatty acids (PUFA, MUFA, SFA). The peri-tumoural spatial distribution (mean, skewness, entropy and kurtosis) of each lipid constituent were then computed. The proliferative activity marker Ki-67 and tumour-infiltrating lymphocytes (TILs) were assessed histologically.

RESULTS

For MUFA, there were significant differences between groups in mean (p = 0.0119), skewness (p = 0.0116), entropy (p = 0.0223), kurtosis (p = 0.0381), and correlations against Ki-67 in mean (ρ = -0.5414), skewness (ρ = 0.6045) and entropy (ρ = 0.6677), and TILs in mean (ρ = -0.4621). For SFA, there were significant differences between groups in mean (p = 0.0329) and skewness (p = 0.0111), and correlation against Ki-67 in mean (ρ = 0.5910). For PUFA, there was no significant difference in mean, skewness, entropy or kurtosis between the groups.

CONCLUSIONS

There was an association between peri-tumoural spatial distribution of lipid composition with tumour cellular differentiation and proliferation. Peri-tumoural lipid composition imaging might have potential in non-invasive quantitative assessment of patients with breast cancer for treatment planning and monitoring.

Periprostatic Adipose Tissue Microenvironment: Metabolic and Hormonal Pathways During Prostate Cancer Progression

The periprostatic adipose tissue (PPAT) is a site of invasion of prostate cancer (PCa) and is part of the microenvironment. It was shown that PPAT secretes factors and fatty acids (FAs) that alter the microenvironment of the PCa. The PPAT secretome of patients with PCa-T3 stage (PPAT-T3) has a metabolic profile enriched in several pathways related to energy production, indicating a greater energy requirement by the tumor, when compared to that of patients in the PCa-T2 stage (PPAT-T2). PPAT-T3 also shows enrichment in pathways related to hormone response, polyamine synthesis, and control of protein synthesis, through amino acid, RNA, and nucleotide metabolism. PPAT-T2 and PPAT-BPH secretomes have less complex metabolic profile, both related with energy balance, while PPAT-BPH has hormone response through insulin pathway. Undoubtedly, a deeper characterization of the human PPAT will lead to a better understanding of the disease and possibly allow new stratification factors and the design of a specific therapy that targets crucial components of the tumor microenvironment as another way to treat or control the disease.

MCF-7 Drug Resistant Cell Lines Switch Their Lipid Metabolism to Triple Negative Breast Cancer Signature

Obesity and adipose tissue have been closely related to a poor cancer prognosis, especially in prostate and breast cancer patients. The ability of transferring lipids from the adipose tissue to the tumor cells is actively linked to tumor progression. However, different types of breast tumor seem to use these lipids in different ways and metabolize them in different pathways. In this study we have tracked by mass spectrometry how palmitic acid from the adipocytes is released to media being later incorporated in different breast cancer cell lines (MDA-MB-231, SKBR3, BT474, MCF-7 and its resistant MCF-7 EPI^R and MCF-7 TAX^R). We have observed that different lines metabolize the palmitic acid in a different way and use their carbons in the synthesis of different new lipid families. Furthermore, we have observed that the lipid synthesis pattern varied according to the cell line. Surprisingly, the metabolic pattern of the resistant cells was more related to the TNBC cell line compared to their sensitive cell line MCF-7. These results allow us to determine a specific lipid pattern in different cell lines that later might be used in breast cancer diagnosis and to find a better treatment according to the cancer molecular type.

Oncogenic Integration of Nucleotide Metabolism via Fatty Acid Synthase in Non-Hodgkin Lymphoma

Metabolic dysfunctions enabling increased nucleotide biosynthesis are necessary for supporting malignant proliferation. Our investigations indicate that upregulation of fatty acid synthase (FASN) and de novo lipogenesis, commonly observed in many cancers, are associated with nucleotide metabolic dysfunction in lymphoma. The results from our experiments showed that ribonucleotide and deoxyribonucleotide pool depletion, suppression of global RNA/DNA synthesis, and cell cycle inhibition occurred in the presence of FASN inhibition. Subsequently, we observed that FASN inhibition caused metabolic blockade in the rate-limiting step of the oxidative branch of the pentose phosphate pathway (oxPPP) catalyzed by phosphogluconate dehydrogenase (PGDH). Furthermore, we determined that FASN inhibitor treatment resulted in NADPH accumulation and inhibition of PGDH enzyme activity. NADPH is a cofactor utilized by FASN, also a known allosteric inhibitor of PGDH. Through cell-free enzyme assays consisting of FASN and PGDH, we delineated that the PGDH-catalyzed ribulose-5-phosphate synthesis is enhanced in the presence of FASN and is suppressed by increasing concentrations of NADPH. Additionally, we observed that FASN and PGDH were colocalized in the cytosol. The results from these experiments led us to conclude that NADP–NADPH turnover and the reciprocal stimulation of FASN and PGDH catalysis are involved in promoting oxPPP and nucleotide biosynthesis in lymphoma. Finally, a transcriptomic analysis of non-Hodgkin’s lymphoma (n = 624) revealed the increased expression of genes associated with metabolic functions interlinked with oxPPP, while the expression of genes participating in oxPPP remained unaltered. Together we conclude that FASN–PGDH enzymatic interactions are involved in enabling oxPPP and nucleotide metabolic dysfunction in lymphoma tumors.

Oxygen and metabolic reprogramming in the tumor microenvironment influences metastasis homing

Tumor metastasis is the leading cause of cancer mortality, often characterized by abnormal cell growth and invasion to distant organs. The cancer invasion due to epithelial to mesenchymal transition is affected by metabolic and oxygen availability in the tumor-associated micro-environment. A precise alteration in oxygen and metabolic signaling between healthy and metastatic cells is a substantial probe for understanding tumor progression and metastasis. Molecular heterogeneity in the tumor microenvironment help to sustain the metastatic cell growth during their survival shift from low to high metabolic-oxygen-rich sites and reinforces the metastatic events. This review highlighted the crucial role of oxygen and metabolites in metastatic progression and exemplified the role of metabolic rewiring and oxygen availability in cancer cell adaptation. Furthermore, we have also addressed potential applications of altered oxygen and metabolic networking with tumor type that could be a signature pattern to assess tumor growth and chemotherapeutics efficacy in managing cancer metastasis.

Plasma lipidomic profiles of kidney, breast and prostate cancer patients differ from healthy controls

Early detection of cancer is one of the unmet needs in clinical medicine. Peripheral blood analysis is a preferred method for efficient population screening, because blood collection is well embedded in clinical practice and minimally invasive for patients. Lipids are important biomolecules, and variations in lipid concentrations can reflect pathological disorders. Lipidomic profiling of human plasma by the coupling of ultrahigh-performance supercritical fluid chromatography and mass spectrometry is investigated with the aim to distinguish patients with breast, kidney, and prostate cancers from healthy controls. The mean sensitivity, specificity, and accuracy of the lipid profiling approach were 85%, 95%, and 92% for kidney cancer; 91%, 97%, and 94% for breast cancer; and 87%, 95%, and 92% for prostate cancer. No association of statistical models with tumor stage is observed. The statistically most significant lipid species for the differentiation of cancer types studied are CE 16:0, Cer 42:1, LPC 18:2, PC 36:2, PC 36:3, SM 32:1, and SM 41:1 These seven lipids represent a potential biomarker panel for kidney, breast, and prostate cancer screening, but a further verification step in a prospective study has to be performed to verify clinical utility.

Circulating fatty acids in patients with head and neck cancer after treatment: an explorative study with a one-year perspective

BACKGROUND

Unintended weight loss and nutritional problems are often seen in patients with head and neck cancer, but changes in lipid metabolism are poorly studied.

AIM/OBJECTIVES

The present study aimed to explore the longitudinal changes in circulating fatty acid (FA) composition in patients with head and neck cancer.

MATERIALS AND METHODS

This study included 27 patients with head and neck cancer. Treatment consisted of single modality or combined modality treatments. The patients were assessed by repeated blood sampling and body weight assessments before treatment started and on three occasions after the start of treatment. FA profiling included gas chromatography analysis of unsaturated FAs and saturated FAs in serum.

RESULTS

The values of three fatty acids - FA 14:0, FA 18:3n3, and FA 20:3n6 - changed in a specific pattern over the course of the study and the change in FA 14:0 correlated with weight changes.

CONCLUSIONS AND SIGNIFICANCE

This study showed altered profiles of both saturated and unsaturated FAs. An improved understanding of the metabolic pathways in patients with head and neck cancer supports the development of better nutritional surveillance and nutritional treatments.

Prostate Cancer Progression: as a Matter of Fats

Advanced prostate cancer (PCa) represents the fifth cause of cancer death worldwide. Although survival has improved with second-generation androgen signaling and Parp inhibitors, the benefits are not long-lasting, and new therapeutic approaches are sorely needed. Lipids and their metabolism have recently reached the spotlight with accumulating evidence for their role as promoters of PCa development, progression, and metastasis. As a result, interest in targeting enzymes/transporters involved in lipid metabolism is rapidly growing. Moreover, the use of lipogenic signatures to predict prognosis and resistance to therapy has been recently explored with promising results. Despite the well-known association between obesity with PCa lethality, the underlying mechanistic role of diet/obesity-derived metabolites has only lately been unveiled. Furthermore, the role of lipids as energy source, building blocks, and signaling molecules in cancer cells has now been revisited and expanded in the context of the tumor microenvironment (TME), which is heavily influenced by the external environment and nutrient availability. Here, we describe how lipids, their enzymes, transporters, and modulators can promote PCa development and progression, and we emphasize the role of lipids in shaping TME. In a therapeutic perspective, we describe the ongoing efforts in targeting lipogenic hubs. Finally, we highlight studies supporting dietary modulation in the adjuvant setting with the purpose of achieving greater efficacy of the standard of care and of synthetic lethality. PCa progression is "a matter of fats", and the more we understand about the role of lipids as key players in this process, the better we can develop approaches to counteract their tumor promoter activity while preserving their beneficial properties.

Dyslipidemia in Chinese Pancreatic Cancer Patients: A Two-Center Retrospective Study

Background: Pancreatic cancer (PC) is one of the most aggressive and lethal malignancies in the world. High cholesterol intake may have a certain association with an elevated risk of PC, though dyslipidemia in PC patients has rarely been reported. In this study, we compared serum lipids levels between PC and non-PC tumor patients and assessed their prognostic value in PC. Methods: 271 patients treated at Wuhan Union Hospital from January 2012 to December 2016 and 204 individuals at Shanghai General Hospital from January 2018 to December 2019 were recruited. Their demographic parameters, laboratory data, pathological information, and clinical outcomes were extracted and analyzed. The mRNA expressions of related lipoprotein, low density lipoprotein receptor (LDLR) and high density lipoprotein binding protein (HDLBP), in PC tissues and paired noncancerous tissues and follow-up information were assessed based on the GEO database (GSE15471 and GSE62165) and TCGA database. Results: A total of 172 non-PC tumor patients and 260 PC patients were finally eligible for our analysis. PC patients exhibited higher levels of serum triglyceride, cholesterol, and low-density lipoprotein (LDL) and a lower serum high-density lipoprotein (HDL) level on admission versus the non-PC tumor group. In PC patients, LDLR mRNA expression was upregulated, and HDLBP mRNA expression was downregulated in cancerous tissues compared to these levels in paired noncancerous tissues. The survival analysis revealed that dyslipidemia had a non-significant association with a poor prognosis, but PC patients with a high LDLR level were at risk of poor survival. Conclusion: Dyslipidemia is detected in PC patients but has a non-significant relation to PC prognosis. However, LDLR may be a potential predictive marker for PC prognosis.

Group III phospholipase A2 downregulation attenuated survival and metastasis in ovarian cancer and promotes chemo-sensitization

Background

Aberrant lipogenicity and deregulated autophagy are common in most advanced human cancer and therapeutic strategies to exploit these pathways are currently under consideration. Group III Phospholipase A2 (sPLA2-III/PLA2G3), an atypical secretory PLA2, is recognized as a regulator of lipid metabolism associated with oncogenesis. Though recent studies reveal that high PLA2G3 expression significantly correlates with poor prognosis in several cancers, however, role of PLA2G3 in ovarian cancer (OC) pathogenesis is still undetermined.

Methods

CRISPR-Cas9 and shRNA mediated knockout and knockdown of PLA2G3 in OC cells were used to evaluate lipid droplet (LD) biogenesis by confocal and Transmission electron microscopy analysis, and the cell viability and sensitization of the cells to platinum-mediated cytotoxicity by MTT assay. Regulation of primary ciliation by PLA2G3 downregulation both genetically and by metabolic inhibitor PFK-158 induced autophagy was assessed by immunofluorescence-based confocal analysis and immunoblot. Transient transfection with GFP-RFP-LC3B and confocal analysis was used to assess the autophagic flux in OC cells. PLA2G3 knockout OVCAR5 xenograft in combination with carboplatin on tumor growth and metastasis was assessed in vivo. Efficacy of PFK158 alone and with platinum drugs was determined in patient-derived primary ascites cultures expressing PLA2G3 by MTT assay and immunoblot analysis.

Results

Downregulation of PLA2G3 in OVCAR8 and 5 cells inhibited LD biogenesis, decreased growth and sensitized cells to platinum drug mediated cytotoxicity in vitro and in in vivo OVCAR5 xenograft. PLA2G3 knockdown in HeyA8MDR-resistant cells showed sensitivity to carboplatin treatment. We found that both PFK158 inhibitor-mediated and genetic downregulation of PLA2G3 resulted in increased number of percent ciliated cells and inhibited cancer progression. Mechanistically, we found that PFK158-induced autophagy targeted PLA2G3 to restore primary cilia in OC cells. Of clinical relevance, PFK158 also induces percent ciliated cells in human-derived primary ascites cells and reduces cell viability with sensitization to chemotherapy.

Conclusions

Taken together, our study for the first time emphasizes the role of PLA2G3 in regulating the OC metastasis. This study further suggests the therapeutic potential of targeting phospholipases and/or restoration of PC for future OC treatment and the critical role of PLA2G3 in regulating ciliary function by coordinating interface between lipogenesis and metastasis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01985-9.

The gate to metastasis: key players in cancer cell intravasation

Metastasis is a leading cause of cancer‐related death and consists of a sequence of events including tumor expansion, intravasation of cancer cells into the circulation, survival in the bloodstream, extravasation at distant sites, and subsequent organ colonization. Particularly, intravasation is a process whereby cancer cells transverse the endothelium and leave the primary tumor site, pioneering the metastatic cascade. The identification of those mechanisms that trigger the entry of cancer cells into the bloodstream may reveal fundamentally novel ways to block metastasis at its start. Multiple factors have been implicated in cancer progression, yet, signals that unequivocally provoke the detachment of cancer cells from the primary tumor are still under investigation. Here, we discuss the role of intrinsic properties of cancer cells, tumor microenvironment, and mechanical cues in the intravasation process, outlining studies that suggest the involvement of various factors and highlighting current understanding and open questions in the field.

Down-regulation of SLC25A20 promotes hepatocellular carcinoma growth and metastasis through suppression of fatty-acid oxidation

Solute carrier family 25 member 20 (SLC25A20) is a mitochondrial-membrane–carrier protein involved in the transport of acylcarnitines into mitochondrial matrix for oxidation. A previous-integrated-proteogenomic study had identified SLC25A20 as one of the top-three prognostic biomarkers in HCC. However, the expression and the biological function of SLC25A20 have not yet been investigated in HCC. In the present study, we found that SLC25A20 expression is frequently down-regulated in HCC cells mainly due to the up-regulation of miR-132-3p. Down-regulation of SLC25A20 is associated with a poor prognosis in patients with HCC. SLC25A20 suppressed HCC growth and metastasis, both in vitro and in vivo, by suppression of G1–S cell transition, epithelial-to-mesenchymal transition (EMT), and induction of cell apoptosis. Mechanistically, SLC25A20 down-regulation promoted HCC growth and metastasis through suppression of fatty-acid oxidation. Altogether, SLC25A20 plays a critical tumor-suppressive role in carcinogenesis of HCC; SLC25A20 may serve as a novel prognostic factor and therapeutic target for patients with HCC.

Hypoxia Dictates Metabolic Rewiring of Tumors: Implications for Chemoresistance

Hypoxia is a condition commonly observed in the core of solid tumors. The hypoxia-inducible factors (HIF) act as hypoxia sensors that orchestrate a coordinated response increasing the pro-survival and pro-invasive phenotype of cancer cells, and determine a broad metabolic rewiring. These events favor tumor progression and chemoresistance. The increase in glucose and amino acid uptake, glycolytic flux, and lactate production; the alterations in glutamine metabolism, tricarboxylic acid cycle, and oxidative phosphorylation; the high levels of mitochondrial reactive oxygen species; the modulation of both fatty acid synthesis and oxidation are hallmarks of the metabolic rewiring induced by hypoxia. This review discusses how metabolic-dependent factors (e.g., increased acidification of tumor microenvironment coupled with intracellular alkalinization, and reduced mitochondrial metabolism), and metabolic-independent factors (e.g., increased expression of drug efflux transporters, stemness maintenance, and epithelial-mesenchymal transition) cooperate in determining chemoresistance in hypoxia. Specific metabolic modifiers, however, can reverse the metabolic phenotype of hypoxic tumor areas that are more chemoresistant into the phenotype typical of chemosensitive cells. We propose these metabolic modifiers, able to reverse the hypoxia-induced metabolic rewiring, as potential chemosensitizer agents against hypoxic and refractory tumor cells.

Coupled Mass-Spectrometry-Based Lipidomics Machine Learning Approach for Early Detection of Clear Cell Renal Cell Carcinoma

A discovery-based lipid profiling study of serum samples from a cohort that included patients with clear cell renal cell carcinoma (ccRCC) stages I, II, III, and IV (n = 112) and controls (n = 52) was performed using ultraperformance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry and machine learning techniques. Multivariate models based on support vector machines and the LASSO variable selection method yielded two discriminant lipid panels for ccRCC detection and early diagnosis. A 16-lipid panel allowed discriminating ccRCC patients from controls with 95.7% accuracy in a training set under cross-validation and 77.1% accuracy in an independent test set. A second model trained to discriminate early (I and II) from late (III and IV) stage ccRCC yielded a panel of 26 compounds that classified stage I patients from an independent test set with 82.1% accuracy. Thirteen species, including cholic acid, undecylenic acid, lauric acid, LPC(16:0/0:0), and PC(18:2/18:2), identified with level 1 exhibited significantly lower levels in samples from ccRCC patients compared to controls. Moreover, 3α-hydroxy-5α-androstan-17-one 3-sulfate, cis-5-dodecenoic acid, arachidonic acid, cis-13-docosenoic acid, PI(16:0/18:1), PC(16:0/18:2), and PC(O-16:0/20:4) contributed to discriminate early from late ccRCC stage patients. The results are auspicious for early ccRCC diagnosis after validation of the panels in larger and different cohorts.

[Research Progress on the Relationship between Blood Lipids and Lung Cancer Risk and Prognosis]

近年来，肺癌成为导致癌症相关死亡的主要原因。越来越多证据表明，许多脂类和脂类类似物是肿瘤发生的关键调节因子，吸烟、饮食及肥胖等影响血脂水平的因素可能与癌症的风险相关。目前随着脂质与肿瘤发生过程关系的研究逐渐深入，探索血脂与肺癌风险及预后相关性已成为研究的热点。本文就血脂水平与肺癌发病风险、血脂水平与肺癌患者预后相关性及调整血脂药物与防治肺癌方向的研究进展进行综述。

Effect of phosphatidylcholine on the stability and lipolysis of nanoemulsion drug delivery systems

Phosphatidylcholines (PCs) have been widely used in pharmaceutical research. Unfortunately, our understanding of how PCs influence the in vivo lipolysis process of drug delivery systems is still limited. In this study, PCs with fatty acid chains of varying lengths and saturability were used as emulsifiers to prepare curcumin-loaded nanoemulsions (Cur-NEs). The differences in particle size as well as drug and free fatty acid release during the lipolysis process were studied in a simulated blood environment. Furthermore, the pharmacokinetics and antitumor efficacy of Cur-NEs were evaluated in mice. The prepared 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)-stabilized Cur-NEs showed similar particle size and stability during storage but exhibited different lipolysis behaviors in vitro and in vivo. Due to the gel state of DPPC in the physiological environment, DPPC-stabilized Cur-NEs had low binding affinity with proteins and maintained their integrity in plasma, leading to sustained drug release, prolonged circulation time and enhanced antitumor efficacy in 4T1 tumor-bearing mice. In contrast, DOPC and DSPC-stabilized Cur-NEs were prone to coalescence in the plasma, resulting in rapid drug release and elimination from circulation. Our findings demonstrated that proper use of PCs is beneficial for obtaining desired transport behavior and drug therapeutic effects, providing guiding principles for rational design of nanodelivery systems.

A STAT3 of Addiction: Adipose Tissue, Adipocytokine Signalling and STAT3 as Mediators of Metabolic Remodelling in the Tumour Microenvironment

Metabolic remodelling of the tumour microenvironment is a major mechanism by which cancer cells survive and resist treatment. The pro-oncogenic inflammatory cascade released by adipose tissue promotes oncogenic transformation, proliferation, angiogenesis, metastasis and evasion of apoptosis. STAT3 has emerged as an important mediator of metabolic remodelling. As a downstream effector of adipocytokines and cytokines, its canonical and non-canonical activities affect mitochondrial functioning and cancer metabolism. In this review, we examine the central role played by the crosstalk between the transcriptional and mitochondrial roles of STAT3 to promote survival and further oncogenesis within the tumour microenvironment with a particular focus on adipose-breast cancer interactions.

Carnitine palmitoyltransferase 1 A expression profile in canine mammary tumors

Genetic alterations and/or epigenetic modifications occur frequently in the majority of cancer cells. In addition to playing a crucial role as promoters of tumorigenesis, these processes can also generate metabolic pathways that are different from those in normal cells. Besides the Warburg effect, an alteration in lipid metabolism is also found in cancer cells. Thus, elucidation of the regulators involved in this metabolic reprogramming might provide tools for diagnosis, prognosis, and ultimately treatment of canine mammary tumours (CMTs) in particular. One such regulator is carnitine palmitoyltransferase 1A (CPT1A), which is involved in transportation of long-chain fatty acids into the mitochondrial matrix for beta-oxidation, thereby providing an alternative pathway for the generation of energy for tumour growth and development. In this study, the canine cell lines MDCK, CMT-U309, CMT-U27, and P114 were used as in vitro models for western blot and quantitative real-time polymerase chain reaction (qRT-PCR) analyses. Furthermore, western blot and immunohistochemistry were carried out to evaluate CPT1A protein expression in the CMT specimens. The CPT1A protein and mRNA expression levels were increased in the CMT cell lines relative to their levels in normal epithelial cells. Moreover, increased CPT1A expression levels were found in the CMT tissues, being inversely correlated with the tumour differentiation grade. However, additional studies are required to further specify the role of CPT1A in CMTs.

NUDT7 Loss Promotes KrasG12D CRC Development

Studies have suggested that dysregulation of peroxisomal lipid metabolism might play an important role in colorectal cancer (CRC) development. Here, we found that Kras^G12D-driven CRC tumors demonstrate dysfunctional peroxisomal β-oxidation and identified Nudt7 (peroxisomal coenzyme A diphosphatase NUDT7) as one of responsible peroxisomal genes. In Kras^G12D-driven CRC tumors, the expression level of Nudt7 was significantly decreased. Treatment of azoxymethane/dextran sulfate sodium (AOM/DSS) into Nudt7 knockout (Nudt7^−/−) mice significantly induced lipid accumulation and the expression levels of CRC-related genes whereas xenografting of Nudt7-overexpressed LS-174T cells into mice significantly reduced lipid accumulation and the expression levels of CRC-related genes. Ingenuity pathway analysis of microarray using the colon of Nudt7^−/− and Nudt7^+/+ mice treated with AOM/DSS suggested Wnt signaling as one of activated signaling pathways in Nudt7^−/− colons. Upregulated levels of β-catenin were observed in the colons of Kras^G12D and AOM/DSS-treated Nudt7^−/− mice and downstream targets of β-catenin such as Myc, Ccdn1, and Nos2, were also significantly increased in the colon of Nudt7^−/− mice. We observed an increased level of palmitic acid in the colon of Nudt7^−/− mice and attachment of palmitic acid-conjugated chitosan patch into the colon of mice induced the expression levels of β-catenin and CRC-related genes. Overall, our data reveal a novel role for peroxisomal NUDT7 in Kras^G12D-driven CRC development.

Ionizing radiation induces cutaneous lipid remolding and skin adipocytes confer protection against radiation-induced skin injury

BACKGROUND

Radiation-induced skin injury is a serious concern during radiotherapy and radiation accidents. Skin fat represents the dominant architectural component of the human skin. However, the interplay between skin fat and the progression of radiation-induced skin injury remains largely unexplored.

OBJECTIVE

This study aims to elucidate the interplay between skin fat and the progression of radiation-induced skin injury.

METHODS

SD rats were irradiated with an electron beam. mRNA profiles were determined by RNA-Seq. The skin lipid mass was monitored by magnetic resonance imaging (MRI) and lipid profiles were measured by liquid chromatography-mass spectrometry (LC-MS). Human mature adipocytes isolated from dermal and subcutaneous white adipose tissues (WATs) were co-cultured with human keratinocytes (HaCaT) and skin fibroblasts (WS1) in the transwell culture system. Cell migration ability was measured by migration assay.

RESULTS

Radiation modulated cutaneous lipid metabolism by downregulating multiple pathways. Moreover, radiation decreased skin fat mass with altered lipid metabolite profiles. The rats fed with a high-fat diet showed resistance to radiogenic skin injury compared with that with a control diet, indicating that skin lipid plays a radioprotective role. Mature adipocytes promoted the migration but not the proliferation of co-cultured skin keratinocytes and fibroblasts. Palmitic acid, the most abundant fatty acid in skin tissues, facilitated the migration of WS1 cells. Moreover, fatty acid-binding protein 4 (FABP4) could be incorporated into skin cells and promote DNA damage repair in irradiated skin fibroblasts.

CONCLUSION

Radiation induces cutaneous lipid remolding, and skin adipocytes confer a protective role against radiation-induced skin injury.

Greasing the Wheels of the Cancer Machine: The Role of Lipid Metabolism in Cancer

Altered lipid metabolism is among the most prominent metabolic alterations in cancer. Enhanced synthesis or uptake of lipids contributes to rapid cancer cell growth and tumor formation. Lipids are a highly complex group of biomolecules that not only constitute the structural basis of biological membranes but also function as signaling molecules and an energy source. Here, we summarize recent evidence implicating altered lipid metabolism in different aspects of the cancer phenotype and discuss potential strategies by which targeting lipid metabolism could provide a therapeutic window for cancer treatment.

Compound C enhances the anticancer effect of aspirin in HER-2-positive breast cancer by regulating lipid metabolism in an AMPK-independent pathway

Various clinical studies have determined that aspirin shows anticancer effects in many human malignant cancers, including human epidermal growth factor receptor-2 (HER-2)-positive breast cancer. However, the anti-tumor mechanism of aspirin has not been fully defined. The aim of this study was to determine the role of Compound C in enhancing the anticancer effect of aspirin. HER-2-positive breast cancer cell lines were treated with aspirin with or without Compound C pre-treatment; their phenotypes and mechanisms were then analyzed in vitro and in vivo. Aspirin exhibited anticancer effects in HER-2-positive breast cancer by inhibiting cell growth and inducing apoptosis through the activation of AMP-activated protein kinase (AMPK). Unexpectedly, pre-treatment with Compound C, a widely used AMPK inhibitor, induced robust anticancer effects in cells compared to aspirin monotherapy. This anticancer effect was not distinct in HER-2 negative breast cancer MDA-MB-231 cells and may be due to the inhibition of lipid metabolism mediated by c-myc. Besides, c-myc re-expression or palmitic acid supply could partially restored cell proliferation. Aspirin exhibits anticancer effects in HER-2-positive breast cancer by regulating lipid metabolism mediated by c-myc, and Compound C strengthens these effects in an AMPK-independent manner. Our results potentially provide a novel therapeutic strategy exploiting combined aspirin and Compound C therapy for HER-2-positive breast cancer, which acts by reducing de novo lipid synthesis.