Natural fatty acid synthase inhibitors as potent therapeutic agents for cancers: A review

Fatty Acid Synthase as Interacting Anticancer Target of the Terpenoid Myrianthic Acid Disclosed by MS-Based Proteomics Approaches

This research focuses on the target deconvolution of the natural compound myrianthic acid, a triterpenoid characterized by an ursane skeleton isolated from the roots of Myrianthus arboreus and from Oenothera maritima Nutt. (Onagraceae), using MS-based chemical proteomic techniques. Application of drug affinity responsive target stability (DARTS) and targeted-limited proteolysis coupled to mass spectrometry (t-LiP-MS) led to the identification of the enzyme fatty acid synthase (FAS) as an interesting macromolecular counterpart of myrianthic acid. This result, confirmed by comparison with the natural ursolic acid, was thoroughly investigated and validated in silico by molecular docking, which gave a precise picture of the interactions in the MA/FAS complex. Moreover, biological assays showcased the inhibitory activity of myrianthic acid against the FAS enzyme, most likely related to its antiproliferative activity towards tumor cells. Given the significance of FAS in specific pathologies, especially cancer, the myrianthic acid structural moieties could serve as a promising reference point to start the potential development of innovative approaches in therapy.

Multi-target action of Garcinia livingstonei extract and secondary metabolites against fatty acid synthase, α-glucosidase, and xanthine oxidase

Garcinia livingstonei is a traditional herbal medicine that showed beneficial health effects and bioactivities. Four compounds have been isolated from the plant leaves and were elucidated as lupeol, betulin, podocarpusflavone A, and amentoflavone. The inhibitory activities of G. livingstonei extract and isolated metabolites against fatty acid synthase (FAS), α-glucosidase, and xanthine oxidase (XO) were investigated in vitro. The affinity of the compounds toward the studied enzymes was investigated in silico. The plant extract inhibited FAS, α-glucosidase, and XO with IC50 values of 26.34, 67.88, and 33.05 µg/mL, respectively. Among the isolated metabolites, betulin exhibited the most inhibitory activity against α-glucosidase and XO with IC50 values of 38.96 and 30.94 µg/mL, respectively. Podocarpusflavone A and betulin were the most potent inhibitors of FAS with IC50 values of 24.08 and 27.96 µg/mL, respectively. Computational studies corroborated these results highlighting the interactions between metabolites and the enzymes. In conclusion, G. livingstonei and its constituents possess the potential to modulate enzymes involved in metabolism and oxidative stress.

Malonyl-CoA is a conserved endogenous ATP-competitive mTORC1 inhibitor

Cell growth is regulated by the mammalian/mechanistic target of rapamycin complex 1 (mTORC1), which functions both as a nutrient sensor and a master controller of virtually all biosynthetic pathways. This ensures that cells are metabolically active only when conditions are optimal for growth. Notably, although mTORC1 is known to regulate fatty acid biosynthesis, how and whether the cellular lipid biosynthetic capacity signals back to fine-tune mTORC1 activity remains poorly understood. Here we show that mTORC1 senses the capacity of a cell to synthesise fatty acids by detecting the levels of malonyl-CoA, an intermediate of this biosynthetic pathway. We find that, in both yeast and mammalian cells, this regulation is direct, with malonyl-CoA binding to the mTOR catalytic pocket and acting as a specific ATP-competitive inhibitor. When fatty acid synthase (FASN) is downregulated/inhibited, elevated malonyl-CoA levels are channelled to proximal mTOR molecules that form direct protein-protein interactions with acetyl-CoA carboxylase 1 (ACC1) and FASN. Our findings represent a conserved and unique homeostatic mechanism whereby impaired fatty acid biogenesis leads to reduced mTORC1 activity to coordinately link this metabolic pathway to the overall cellular biosynthetic output. Moreover, they reveal the existence of a physiological metabolite that directly inhibits the activity of a signalling kinase in mammalian cells by competing with ATP for binding.

Classification analysis of fatty acid synthase inhibitors using multialgorithms on topological descriptors and structural fingerprints

Fatty acid synthase (FASN) is one of the enzymes required for fatty acid biosynthesis and is expressed as low or absent in most normal cells/tissues. However, this enzyme is upregulated in various cancer cells; hence, it can act as an important target to design and develop novel FASN inhibitors for cancer therapy. In the present investigation, a series of structurally diverse compounds that possessed FASN inhibitory activities were subjected to classification analysis using different algorithms such as support vector machine, decision tree, Naïve Bayes and random forest. The physicochemical descriptors and MACCS fingerprints were calculated using PaDEL software, and the WEKA software was utilized for the classification model building. The statistical parameters/confusion matrix calculated from the analysis revealed that the selected models have significant predictive performances. The results showed that the topological properties of the molecules are the main determinant for the activity classification. The key descriptors comprised of hydrogen bonding groups, especially acceptor (nHBAcc, minHBint9, minHBint5 and nwHBa), charge on the topological surface of the molecules (JGI10 & GGI2), ionization potential (GATS5i and GATS1i) and branching and distance between the groups (ETA_Eta_B_RC) are significantly contributed in the classification models. Further, the presence of heteroatoms (MACCSFP82, MACCSFP93 and MACCSFP131), especially nitrogen atom(s) and hydrogen bond acceptor groups (N-N group, NC(=O)N, N-C(=O)), actively contributed to the inhibitory activities. The results concluded that the topological polar properties concentrated in a specific region have significant FASN inhibitory activity. Hence, these results shall be used to develop novel molecules with increased FASN inhibitory activity.

Fatty Acid Synthase (FASN): A Patent Review Since 2016-Present

INTRODUCTION

Fatty acid synthase (FASN), is a key metabolic enzyme involved in fatty acid biosynthesis and is an essential target for multiple disease progressions like cancer, obesity, NAFLD, etc. Aberrant expression of FASN is associated with deregulated energy metabolism of cells in these diseases.

AREA COVERED

This article provides a summary of the most recent developments in the discovery of novel FASN inhibitors with potential therapeutic uses in cancer, obesity, and other metabolic disorders such as nonalcoholic fatty liver disease from 2016 to the present. The recently published patent applications and forthcoming clinical data of FASN inhibitors from both academia and the pharma industries are also highlighted in this study.

EXPERT OPINION

The implication of FASN in multiple diseases has provided an impetus for developing novel inhibitors by both pharma companies and academia. Critical analysis of the patent literature reveals the exploration of diverse molecular scaffolds to identify potential FASN inhibitors that target the different catalytic domains of the enzyme. In spite of these multifaceted efforts, only one molecule, TVB-2640, has reached phase II trials for nonalcoholic steatohepatitis (NASH) and many malignancies. However, thecombined efforts of pharma companies to produce several FASN inhibitors might facilitate the clinical translation of this unique class of inhibitors. Nevertheless, concerted efforts towards developing multiple FASN inhibitors by pharma companies might facilitate the clinical translation of this novel class of inhibitors.

Xanthomicrol Activity in Cancer HeLa Cells: Comparison with Other Natural Methoxylated Flavones

The methoxylated flavone xanthomicrol represents an uncommon active phenolic compound identified in herbs/plants with a long application in traditional medicine. It was isolated from a sample of Achillea erba-rotta subsp. moschata (musk yar-row) flowering tops. Xanthomicrol promising biological properties include antioxidant, anti-inflammatory, antimicrobial, and anticancer activities. This study mainly focused on the evaluation of the xanthomicrol impact on lipid metabolism in cancer HeLa cells, together with the investigation of the treatment-induced changes in cell growth, morphology, and apoptosis. At the dose range of 5-100 μM, xanthomicrol (24 h of incubation) significantly reduced viability and modulated lipid profile in cancer Hela cells. It induced marked changes in the phospholipid/cholesterol ratio, significant decreases in the levels of oleic and palmitic acids, and a marked increase of stearic acid, involving an inhibitory effect on de novo lipogenesis and desaturation in cancer cells. Moreover, marked cell morphological alterations, signs of apoptosis, and cell cycle arrest at the G2/M phase were observed in cancer treated cells. The bioactivity profile of xanthomicrol was compared to that of the anticancer methoxylated flavones eupatilin and artemetin, and structure-activity relationships were underlined.

Approaches to Measuring the Activity of Major Lipolytic and Lipogenic Enzymes In Vitro and Ex Vivo

Since the 1950s, one of the goals of adipose tissue research has been to determine lipolytic and lipogenic activity as the primary metabolic pathways affecting adipocyte health and size and thus representing potential therapeutic targets for the treatment of obesity and associated diseases. Nowadays, there is a relatively large number of methods to measure the activity of these pathways and involved enzymes, but their applicability to different biological samples is variable. Here, we review the characteristics of mean lipogenic and lipolytic enzymes, their inhibitors, and available methodologies for assessing their activity, and comment on the advantages and disadvantages of these methodologies and their applicability in vivo, ex vivo, and in vitro, i.e., in cells, organs and their respective extracts, with the emphasis on adipocytes and adipose tissue.

Cucurbitane triterpenoid entities derived from Hemsleya penxianensis triggered glioma cell apoptosis via ER stress and MAPK signalling cross-talk

In the present study, six new cucurbitane type compounds, including three triterpenoids hemsleyacins P-R (6-7, 13) and three cucurbitane-type triterpenoid glycosides hemsleyaosides L-N (15-17), along with seventeen known cucurbitacin analogues were separated from the root tuber of Hemsleya penxianensis and elucidated based on NMR and HRESIMS. Then, 23 analogues of three types, namely, polyhydroxy-type (I) (1-7), monohydroxy-type (II) (8-13), and glycosides-type (III) (14-23), were assessed for their antitumor activity and structure-activity relationship analysis (SAR). We determined temozolomide (TMZ)-resistant GBM cell was the most sensitive to the tested compounds, and found hemsleyaoside N (HDN) displayed the best antineoplastic potency. Furthermore, we confirmed the anti-glioma activity of HDN in patient-derived recurrent GBM strains, GBM organoid (GBO) and orthotopic nude mouse models. Investigations exploring the mechanism made clear that HDN induced synchronous activation of UPR and MAPK signaling, which triggered deadly ER stress and apoptosis. Taken together, the potent antitumor activity of HDN warrants further comprehensive evaluation as a novel anti-glioma agent.

Fatty acid synthase: A druggable driver of breast cancer brain metastasis

INTRODUCTION

Brain metastasis (BrM) is a key contributor to morbidity and mortality in breast cancer patients, especially among high-risk epidermal growth factor receptor 2-positive (HER2+) and triple-negative/basal-like molecular subtypes. Optimal management of BrM is focused on characterizing a "BrM dependency map" to prioritize targetable therapeutic vulnerabilities.

AREAS COVERED

We review recent studies addressing the targeting of BrM in the lipid-deprived brain environment, which selects for brain-tropic breast cancer cells capable of cell-autonomously generating fatty acids by upregulating de novo lipogenesis via fatty acid synthase (FASN). Disruption of FASN activity impairs breast cancer growth in the brain, but not extracranially, and mapping of the molecular causes of organ-specific patterns of metastasis has uncovered an enrichment of lipid metabolism signatures in brain metastasizing cells. Targeting SREBP1-the master regulator of lipogenic gene transcription-curtails the ability of breast cancer cells to survive in the brain microenvironment.

EXPERT OPINION

Targeting FASN represents a new therapeutic opportunity for patients with breast cancer and BrM. Delivery of brain-permeable FASN inhibitors and identifying strategies to target metabolic plasticity that might compensate for impaired brain FASN activity are two potential roadblocks that may hinder FASN-centered strategies against BrM.

The effect of bile salt diet supplementation on genes related to fat metabolism in yellow-feathered broilers

Background and Aim:

As a new feed additive, bile acid (BA) can promote the absorption and transport of lipids and fat-soluble vitamins. In recent years, BAs have been widely used in animal feed to promote fat absorption. Therefore, this study aimed to investigate the effect of bile salt supplementation in the diet of yellow-feathered broilers on messenger RNA (mRNA) expression of sterol regulatory element-binding protein 1 (SREBF1), fatty acid synthase (FAS), acetyl-coenzyme A carboxylase (ACC), and fatty acid transport protein 4 (FATP4).

Materials and Methods:

Four hundred and twenty commercial male chicks were randomly divided into seven groups (with four replicates per group and 15 chickens per replicate). They were fed diets supplemented with bile salts at 0, 1.5, 2.5, 3.5, 4.5, 5.5 mg/kg, and 2 mg/kg tylosin for 30 days. Changes in SREBF1, fatty acid transporter 4, FAS, and acetyl-CoA carboxylase genes in intestinal mucosa and liver of yellow-feathered broilers were determined using a quantitative fluorescence polymerase chain reaction.

Results:

mRNA expression of SREBF1, FAS, ACC, and FATP4 in the small intestine decreased in chicks fed diets supplemented with 3.5 and 4.5 mg/kg bile salts (p<0.05) compared with the control group on 7 days and 14 d. The mRNA expressions of SREBF1, FAS, ACC, and FATP4 in liver tissue decreased in chicks fed diets supplemented with 4.5 and 5.5 mg/kg bile salts (p<0.05) compared to the control group on 7 days. The mRNA expression of SREBF1, FAS, ACC, and FATP4 in the liver at 14 days and the small intestine on 21 days also decreased in chicks fed diets supplemented with 4.5 mg/kg bile salts (p<0.05) compared to the control group. When contrasted with the control group on day 21, the mRNA expression of SRWBF1, FAS, ACC, and FATP4 detected in the liver was lower in chicks fed diets supplemented with bile salts (p<0.05).

Conclusion:

The dietary supplementation of bile salts at 4.5 mg/kg effectively regulates the expression of fat metabolism genes, such as SREBF1, FAS, ACC, and FATP4 mRNA. At this concentration, bile salts promote fat catabolism, inhibit fat synthesis, and play an essential role in improving the fat deposition of broilers.

Decreased expression of miR-195 mediated by hypermethylation promotes osteosarcoma

Osteosarcoma (OS) is the most common type of primary malignant bone tumor. The early lung metastasis of osteosarcoma is one of the main factors of poor prognosis. Therefore, searching for new targets and new mechanisms of osteosarcoma metastasis is essential for the prevention and treatment of osteosarcoma. Our previous studies suggested that fatty acid synthase (FASN) was an oncogene and promoted osteosarcoma. In addition, it is reported that the expression of miR-195 was negatively correlated with osteosarcoma. Aberrant DNA methylation can reversely regulate the expression of miRNAs. However, whether miR-195 could target FASN in osteosarcoma and whether ectopic DNA methylation is the upstream regulatory mechanism of miR-195 in metastasis of osteosarcoma are not fully studied. The expressions were detected by qPCR and western blot, and methylation level was determined by methylation-specific PCR. Luciferase reporter assay, MTT, wound healing, and Transwell assay were used. We found that the expression of miR-195 was low in osteosarcoma. The methylation of miR-195 was high. miR-195 targeted and decreased the expression of FASN. In osteosarcoma, miR-195 inhibited cell proliferation, cell migration, and invasion. The methylation of miR-195 was related to decreased miR-195, it might promote osteosarcoma.

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.

Characterization and differentiation potential of mesenchymal stem cells isolated from multiple canine adipose tissue sources

Background

Mesenchymal stem cells (MSCs) are undifferentiated cells that can give rise to a mesoderm lineage. Adipose-derived MSCs are an easy and accessible source for MSCs isolation, although each source of MSC has its own advantages and disadvantages. Our study identifies a promising source for the isolation and differentiation of canines MSCs. For this purpose, adipose tissue from inguinal subcutaneous (SC), perirenal (PR), omental (OM), and infrapatellar fat pad (IPFP) was isolated and processed for MSCs isolation. In the third passage, MSCs proliferation/metabolism, surface markers expression, in vitro differentiation potential and quantitative reverse transcription PCR (CD73, CD90, CD105, PPARγ, FabP4, FAS, SP7, Osteopontin, and Osteocalcin) were evaluated.

Results

Our results showed that MSCs derived from IPFP have a higher proliferation rate, while OM-derived MSCs have higher cell metabolism. In addition, MSCs from all adipose tissue sources showed positive expression of CD73 (NT5E), CD90 (THY1), CD105 (ENDOGLIN), and very low expression of CD45. The isolated canine MSCs were successfully differentiated into adipogenic and osteogenic lineages. The oil-red-O quantification and adipogenic gene expression (FAS, FabP4, and PPARγ) were higher in OM-derived cells, followed by IPFP-MSCs. Similarly, in osteogenic differentiation, alkaline phosphatase activity and osteogenic gene (SP7 and Osteocalcin) expression were higher in OM-derived MSCs, while osteopontin expression was higher in PR-derived MSCs.

Conclusion

In summary, among all four adipose tissue sources, OM-derived MSCs have better differentiation potential toward adipo- and osteogenic lineages, followed by IPFP-MSCs. Interestingly, among all adipose tissue sources, MSCs derived from IPFP have the maximum proliferation potential. The characterization and differentiation potential of canine MSCs isolated from four different adipose tissue sources are useful to assess their potential for application in regenerative medicine.

Effect of the natural polymethoxylated flavone artemetin on lipid oxidation and its impact on cancer cell viability and lipids

The biochemical class of the polymethoxylated flavonoids represents uncommon phenolic compounds in plants presenting a more marked lipophilic behavior due to the alkylation of its hydroxylic groups. As a polymethoxylated flavone, which concerns a different bioavailability, artemetin (ART) has been examined in vitro against lipid oxidation and its impact on cancer cells has been explored. Despite this flavone only exerted a slight protection against in vitro fatty acid and cholesterol oxidative degradation, ART significantly reduced viability and modulated lipid profile in cancer Hela cells at the dose range 10-50 μM after 72 h of incubation. It induced marked changes in the monounsaturated/saturated phospholipid class, significant decreased the levels of palmitic, oleic and palmitoleic acids, maybe involving an inhibitory effect on de novo lipogenesis and desaturation in cancer cells. Moreover, ART compromised normal mitochondrial function, inducing a noteworthy mitochondrial membrane polarization in cancer cells. A dose-dependent absorption of ART was evidenced in HeLa cell pellets (15.2% of the applied amount at 50 μM), coupled to a marked increase in membrane fluidity, as indicate by the dose-dependent fluorescent Nile Red staining (red emissions). Our results validate the ART role as modulatory agent on cancer cell physiology, especially impacting viability, lipid metabolism, cell fluidity, and mitochondrial potential.

Aster glehni F. Schmidt Extract Modulates the Activities of HMG-CoA Reductase and Fatty Acid Synthase

Aster glehni F. Schmidt (AG), is a natural product known to have anti-obesity effects, but the mechanism underlying these effects is not well documented. We hypothesized that AG may have inhibitory effects on enzymes related to lipid accumulation. Herein, AG fractions were tested against HMG-CoA reductase (HMGR) and fatty acid synthase (FAS), two important enzymes involved in cholesterol and fatty acid synthesis, respectively. We found that dicaffeoylquinic acid (DCQA) methyl esters present in AG are largely responsible for the inhibition of HMGR and FAS. Since free DCQA is a major form present in AG, we demonstrated that a simple methylation of the AG extract could increase the overall inhibitory effects against those enzymes. Through this simple process, we were able to increase the inhibitory effect by 150%. We believe that our processed AG effectively modulates the HMGR and FAS activities, providing promising therapeutic potential for cholesterol- and lipid-lowering effects.

Effects of quercetin and artemetin prenylation on bioavailability and bioactivity

Flavonoids are a huge class of polyphenolic compounds ubiquitous in higher plants, in most food and beverages of natural origin. They could be considered as dietary phenols, which exert many health-promoting effects on human and animal physiology with a wide range of biomedical and nutritional functions such as activation or inhibition of enzymes like lipoxygenase and cyclooxygenase, the detoxification of carcinogens and chemoprevention. From a chemical point of view, these aromatic compounds can be divided in six subgroups depending on the position of aromatic B ring on C ring, the degree of unsaturation and oxidation, the position of hydroxyl groups and their functionalization. Between flavonoids, the prenylated ones represent a unique class occurring in nature where the C-prenylation is the most common, whereas O-prenylation is rarely present. The presence of this lipophilic functional group in different positions on the scaffold of flavonoids can sometimes lead to relevant changes in their biological activity due to an increased bioavailability. Capitalizing on the restricted incidence in nature of prenylated flavonoids, we have assessed the synthesis of C- and O-prenylated derivatives starting from two flavonoids, quercetin and artemetin, aimed at the exploration of structure-activity relationships. Results showed that prenylation significantly increased the cytotoxic effect of flavonoids in cancer HeLa cells, also improving their capacity to affect cell phospholipid and fatty acid composition. A marked cell bioavailability increase was demonstrated for the artemetin C-prenylated derivative.

Review on target domains and natural compound-based inhibitors of fatty acid synthase for anticancer drug discovery

Cancer cells require a higher amount of energy in the form of fatty acids for their uncontrolled proliferation and growth. Fatty acid synthase (FASN) plays a crucial role in the synthesis of palmitate, which is involved in most of the critical malignant pathways. Hence, by targeting FASN, tumour growth can be controlled. By designing and developing FASN inhibitors with catalytic domain specificity, safe and potential anticancer drugs can be achieved. The article draws light towards the catalytic domains of FASN, their active site residues and interaction of some of the reported natural FASN inhibitors (resveratrol, lavandulyl flavonoids, catechins, stilbene derivatives, etc). The rationality (structure-activity relationship) behind the variation in the activity of the reported natural FASN inhibitors (butyrolactones, polyphenolics, galloyl esters and thiolactomycins) has also been covered. Selective, safe and potentially active FASN inhibitors could be developed by: (i) having proper understanding of the function of all catalytic domains of FASN (ii) studying the upstream and downstream FASN regulators (iii) identifying cancer-specific FASN biomarkers (that are non-essential/absent in the normal healthy cells) (iv) exploring the complete protein structure of FASN, e-screening of the compounds prior to synthesis and study their ADME properties (v) predicting the selectivity based on their strong affinity at the catalytic site of FASN.

The dietary flavonoid eupatilin attenuates in vitro lipid peroxidation and targets lipid profile in cancer HeLa cells

Eupatilin is a dietary flavonoid isolated from the alpine wormwoods, used for the genepy liqueur production. This flavone protects cells and tissues against oxidative stress and targets cancer cells, inducing cytotoxicity, cell circle arrest, apoptosis and mitochondrial dysfunction. This study examines the EUP in vitro antioxidant effects on cholesterol and phospholipid membrane oxidation and explores its ability to modulate the cancer cell lipid profile. This flavone remarkably protected fatty acids and cholesterol against oxidative degradation by scavenging lipoperoxyl radicals. EUP (24 h of incubation) significantly reduced viability and modulated the total lipid and fatty acid profiles in cancer HeLa cells. It induced marked changes in the phospholipid/cholesterol ratio, significant decreases in the levels of oleic and palmitic acids and a marked increase of stearic acid, involving an inhibitory effect on de novo lipogenesis and desaturation in cancer cells. Moreover, a noteworthy mitochondrial membrane depolarization, signs of apoptosis, abnormal mitosis with multi-nucleation (mitotic catastrophe) and morphological alterations were observed in cancer EUP-treated cells. Our results validate the EUP role as antioxidant agent for the treatment/prevention of disorders implicating a membrane lipid oxidative damage and substantiate cell lipid metabolism as another possible target of this dietary natural flavonoid in cancer HeLa cells.

Effect of extract from common oat on the antioxidant activity and fatty acid composition of the muscular tissues of geese

Among natural antioxidants, increasing attention is being drawn to avenanthramides - phenolic compounds of the common oat Avena sativa (Linnaeus, 1753). Research has shown that avenanthramides have much higher antioxidant activity than well-known bioflavanoids. Currently, a great deal of work is being conducted on the structure of these compounds and mechanisms of their effect on the organism of humans and animals. We explored the specifics of the influence of aqueous extract from A. satíva on the antioxidant activity and fatty acid composition of lipids of histologically similar tissues of geese with different levels of aerobicity (muscles of the stomach and cardiac muscle), dynamics of the birds’ live weight and pterylographic parameters under physiological loading by the development of contour and juvenile feathers. The addition of extract of oat to the diet of geese during growth of feathers was observed to increase the antioxidant activity of their tissues. Physiological loading related to the development of contour feathers in the examined tissues of geese significantly weakens as a result of selective inhibition of synthesis of unsaturated fatty acids, especially oleic acid, the content of which in 28-day old geese of the experimental group decreased by 31.7 in the cardiac muscle and 46.8 times in the stomach, compared with the control. Further changes in fatty acid composition were characterized by lower number of differences between the control and experimental groups. Increase in antioxidant activity in these tissues during development of juvenile feathers (day 49) occurs as a result of activation of alternative mechanisms of antioxidative protection, which take place with no significant changes in fatty acid composition. Furthermore, we determined that in the stomach and cardiac muscles of geese, the action of extract from common oat activated mechanisms of antioxidative protection, which increased the level of correlation between the changes in fatty acid composition. The study confirmed that the extract caused not only significant increase in the weight of geese at the end of the experiment, but also improved their pterylographic parameters. Therefore, it is practical to conduct similar studies on wild species of birds grown for hunting, because this process of development of feathers, particularly for such species of birds, is essential.

6-Shogaol induces apoptosis in acute lymphoblastic leukaemia cells by targeting p53 signalling pathway and generation of reactive oxygen species

Combination therapies, using medicinal herbs, are broadly recommended to attenuate the chemotherapy adverse effects. Based on our previous findings considering the anti-leukaemic effects of ginger extract on acute lymphoblastic leukaemia (ALL) cells, the present study was aimed to investigate the anti-cancer role of this pharmaceutical plant on ALL mice models. Moreover, we worked towards identifying the most anti-leukaemic derivative of ginger and the mechanism through which it may exert its cytotoxic impact. In vivo experiments were performed using five groups of six C57BL/6 nude mice, and the anti-leukaemic activity of ginger extract alone or in combination with methotrexate (MTX) was examined. Results showed increased survival rate and reduced damages in mice brain and liver tissues. Subsequently, MTT assay demonstrated synergistic growth inhibitory effect of 6-shogaol (6Sh) and MTX on ALL cell lines and patients primary cells. Eventually, the molecular anti-neoplastic mechanism of 6Sh was evaluated using Bioinformatics. Flow cytometry illustrated 6Sh-mediated apoptosis in Nalm-6 cells confirmed by Western blotting and RT-PCR assays. Further analyses exhibited the generation of reactive oxygen species (ROS) through 6Sh. The current study revealed the in vivo novel anti-leukaemic role of ginger extract, promoted by MTX. Moreover, 6-shogaol was introduced as the major player of ginger cytotoxicity through inducing p53 activity and ROS generation.

Moschamindole induces glioma cell apoptosis by blocking Mia40-dependent mitochondrial intermembrane space assembly and oxidative respiration

Glioblastoma multiforme (GBM) is the most frequent, lethal, and aggressive tumor of the central nervous system in adults. In this study, we found for the first time that moschamindole (MCD), a rare phenolic amide with 8/6/6/5/5 rings, is a major bioactive constituent derived from Phragmites communis Trin (Poaceae) that exhibits a potential cytotoxic effect on both TMZ-resistant GBM cell lines and xenograft models. MCD-induced intrinsic apoptosis signals and mitochondrial dysfunction were confirmed by cell cycle arrest, caspase-3/7 activation, and membrane potential depolarization. Furthermore, investigations exploring the mechanism showed that MCD specifically inhibits Mia40-mediated oxidative folding of mitochondrial intermembrane space (IMS) proteins via PCR assay and immunoblot analysis. MCD relies on its positive charge to associate with mitochondrial oxidative respiration, thus blocking energy metabolism and inducing apoptosis. Overexpression and upregulation of Mia40 were proven to reverse MCD-induced apoptosis and were correlated with the chemoresistance of GBM in vitro and in vivo, respectively. Taken together, our study demonstrates that Mia40 is a potential target of the chemoresistance of glioblastoma and suggests that MCD might be a potential agent for the individualized treatment of chemoresistant GBM based on mitochondrial metabolic characteristics and Mia40 expression.

Bioactivity of natural biflavonoids in metabolism-related disease and cancer therapies

Natural biflavonoids, such as amentoflavone, bilobetin, ginkgetin, isoginkgetin, taiwaniaflavone, morelloflavone, delicaflavone, hinokiflavone, and other derivatives (~ 40 biflavonoids), are isolated from Selaginella sp., Ginkgo biloba, Garcinia sp., and several other species of plants. They are able to exert therapeutic benefits by regulating several proteins/enzymes (PPAR-γ, CCAAT/enhancer-binding protein α [C/EBPα], STAT5, pancreatic lipase, PTP1B, fatty acid synthase, α-glucosidase [AG]) and insulin signaling pathways (via PI3K-AKT), which are linked to metabolism, cell growth, and cell survival mechanisms. Deregulated insulin signaling can cause complications of obesity and diabetes, which can lead to cognitive disorders such as Alzheimer's, Parkinson's, and dementia; therefore, the therapeutic benefits of these biflavones in these areas are highlighted. Since biflavonoids have shown potential to regulate metabolism, growth- and survival-related protein/enzymes, their relation to tumor growth and metastasis of cancer associated with angiogenesis are highlighted. The translational role of biflavones in cancer with respect to the inhibition of metabolism-related processes/pathways, enzymes, or proteins, such as STAT3/SHP-1/PTEN, kinesins, tissue kallikreins, aromatase, estrogen, protein modifiers, antioxidant, autophagy, and apoptosis induction mechanisms, are discussed. Finally, considering their observed bioactivity potential, oral bioavailability studies of biflavones and related clinical trials are outlined.

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

Fatty acids are closely involved in lipid synthesis and metabolism in cancer. Their amount and composition are dependent on dietary supply and tumor microenviroment. Research in this subject highlighted the crucial event of membrane formation, which is regulated by the fatty acids' molecular properties. The growing understanding of the pathways that create the fatty acid pool needed for cell replication is the result of lipidomics studies, also envisaging novel fatty acid biosynthesis and fatty acid-mediated signaling. Fatty acid-driven mechanisms and biological effects in cancer onset, growth and metastasis have been elucidated, recognizing the importance of polyunsaturated molecules and the balance between omega-6 and omega-3 families. Saturated and monounsaturated fatty acids are biomarkers in several types of cancer, and their characterization in cell membranes and exosomes is under development for diagnostic purposes. Desaturase enzymatic activity with unprecedented de novo polyunsaturated fatty acid (PUFA) synthesis is considered the recent breakthrough in this scenario. Together with the link between obesity and cancer, fatty acids open interesting perspectives for biomarker discovery and nutritional strategies to control cancer, also in combination with therapies. All these subjects are described using an integrated approach taking into account biochemical, biological and analytical aspects, delineating innovations in cancer prevention, diagnostics and treatments.

Structure-based virtual screening to identify novel carnitine acetyltransferase activators

Carnitine acetyltransferase (CAT) is an attractive therapeutic target against fibrosis. We have identified few CAT activators through structure-based virtual screening followed by molecular dynamics simulations for assessment of the binding mode. A set of 10,000 drug-like molecules properly filtered from an initial chemical library of 13 M commercially available compounds were docked into the active site. Virtual hits were selected for in vitro experimental testing to validate the computational findings and the stability of the predicted complexes was evaluated by molecular dynamics simulations. Applied protocol led to the identification of three hit compounds showing promising activity, which can serve as potential scaffolds for further structural optimization. This is the first report of successful discovery of CAT activators through the use of structure-based virtual screening.

Inhibitors of lipogenic enzymes as a potential therapy against cancer

Cancer cells rely on several metabolic pathways such as lipid metabolism to meet the increase in energy demand, cell division, and growth and successfully adapt to challenging environments. Fatty acid synthesis is therefore commonly enhanced in many cancer cell lines. Thus, relevant efforts are being made by the scientific community to inhibit the enzymes involved in lipid metabolism to disrupt cancer cell proliferation. We review the rapidly expanding body of inhibitors that target lipid metabolism, their side effects, and current status in clinical trials as potential therapeutic approaches against cancer. We focus on their molecular, biochemical and structural properties, selectivity and effectiveness and discuss their potential role as antitumor drugs.

Stable Isotope Tracing Metabolomics to Investigate the Metabolic Activity of Bioactive Compounds for Cancer Prevention and Treatment

A major hallmark of cancer is the metabolic reprogramming of cancer cells to fuel tumor growth and proliferation. Various plant-derived bioactive compounds efficiently target the metabolic vulnerabilities of cancer cells and exhibit potential as emerging therapeutic agents. Due to their safety and common use as dietary components, they are also ideal for cancer prevention. However, to render their use as efficient as possible, the mechanism of action of these phytochemicals needs to be well characterized. Stable isotope tracing is an essential technology to study the molecular mechanisms by which nutraceuticals modulate and target cancer metabolism. The use of positionally labeled tracers as exogenous nutrients and the monitoring of their downstream metabolites labeling patterns enable the analysis of the specific metabolic pathway activity, via the relative production and consumption of the labeled metabolites. Although stable isotope tracing metabolomics is a powerful tool to investigate the molecular activity of bioactive compounds as well as to design synergistic nutraceutical combinations, this methodology is still underutilized. This review aims to investigate the research efforts and potentials surrounding the use of stable isotope tracing metabolomics to examine the metabolic alterations mediated by bioactive compounds in cancer.

The TLC-Bioautography as a Tool for Rapid Enzyme Inhibitors detection - A Review

Microorganisms and plants can be important sources of many compounds with potential pharmaceutical applications. Extraction of these matrices is one of the ways of identifying the presence of inhibitory active substances against enzymes whose high activity leads to serious human diseases including cancer, Parkinson's or Crohn's diseases. The isolation and purification of inhibitors are time-consuming and expensive steps in the analysis of the crude extract and therefore, it is necessary to find a fast, efficient, and inexpensive method for screening extracts of interest. TLC-Bioautography combines the separation of the extract on a thin layer with its subsequent biological analysis. TLC-Bioautography methods have been developed for several classes of enzymes including oxidoreductases, hydrolases and isomerases, and there is a potential for developing functional methods for other classes of enzymes. This review summarizes known TLC-Bioautography methods and their applications for determining the presence of enzyme inhibitors in extracts and compares the effectiveness of different methodological approaches. It also indicates the current state and perspective of the development of TLC-Bioautography and its possible future applications.

Research on the effects of L-carnitine and trans-chalcone on endoplasmic reticulum stress and oxidative stress in high-fructose corn syrup-fed rats

Purpose

The debate on the metabolic effects of high fructose corn syrup (HFCS) continues. The deterioration of endoplasmic reticulum (ER) homeostasis is called ER stress. Glucose-regulated protein-78 (GRP-78) and X-box binding protein-1 (XBP-1) are key markers of ER stress and the therapeutic targets of diseases. Sterol regulatory element binding protein-1c (SREBP-1c) is the most important transcription factor that regulates the expression of enzymes for fatty acid synthesis. The purpose of this paper is to research the effects of L-carnitine and trans-chalcone on ER stress and oxidative stress parameters, and to explore the therapeutic potential of L-carnitine and trans-chalcone molecules.

Design/methodology/approach

Forty male wistar albino rats randomly selected were divided into five groups. All groups are fed with standard chow (ad libitum). While Group I was fed with drinking water, Group II, III, IV and V were fed with water containing 15% HFCS. L-carnitine was given to Group IV and trans-chalcone to Group V, and both were dissolved with DMSO and given intraperitoneally. Group III was not given anything additional.

Findings

While the amount of water consumption of HFCS-fed rats has increased, the amount of feed consumption has decreased. The weights of rats in Group II and Group III have increased significantly compared to Group I (p = 0.001, p = 0.001 respectively). In Group III, GRP78, XBP-1; malondialdehyde level (p < 0.001, p = 0.001, p = 0.041); total cholesterol, triglyceride, LDL levels (p = 0.001, p < 0.001, p = 0.009, p = 0.001, respectively) have increased significantly.

Originality/value

To the best of the authors’ knowledge, this study is the first report to show that excessive HFCS consumption causes oxidative stress and ER stress. The antioxidant and antiobesity properties of trans chalcone have been demonstrated. Extensive experimental and clinical studies should be conducted.

Comparative studies of two vegetal extracts from Stokesia laevis and Geranium pratense: polyphenol profile, cytotoxic effect and antiproliferative activity

In this study, two ethanolic extracts, fromStokesia aster(Slae26) andGeranium pratense(Gpre36) respectively, were evaluated in order to assess the cytotoxic activity and potential antiproliferative activity upon the nontumorigenic human epithelial cell line derived from the mammary gland (MCF-12A) and the human breast tumor cell line (BT-20). The selection of the plant species was done on the basis of their chemical composition, specifically combinations of luteolin derivatives with caffeic and gallic acid derivatives. Therefore, theS. laevisethanolic extract proved its capacity to inhibit the viability of both normal and tumor breast cell lines (i.e., up to 90% cell viability inhibition, IC50= 42 µg/mL). On the contrary, theG. pratenseethanolic extract proved weak stimulatory effects on the viability of the two human breast cell lines studied. The obtained results were discussed in the contexts of computational studies and drug-likeness bioactivity of seven common luteolin derivatives: luteolin, luteolin-7-O-glucoside/cynaroside, luteolin-5-O-glucoside/galuteolin, luteolin-6-C-glucoside/isoorientin, luteolin-8-C-glucoside/orientin, luteolin-3′,4′-di-O-glucoside and luteolin-7,3′-di-O-glucoside. Computational studies have revealed that the hydrophilic behavior of luteolin derivatives (log Pvalues) does not follow other tested parameters (e.g., polar surface area values), possibly explaining different efficacy concerning the biological propertiesin vitro. These predictions could be a starting point for studies on the biochemical mechanism by which luteolin derivatives induce biological effects.

Genomic characteristics and comparative genomics analysis of the endophytic fungus Sarocladium brachiariae

BACKGROUND

Sarocladium brachiariae is a newly identified endophytic fungus isolated from Brachiaria brizantha. A previous study indicated that S. brachiariae had antifungal activity; however, limited genomic information restrains further study. Therefore, we sequenced the genome of S. brachiariae and compared it with the genome of S. oryzae to identify differences between a Sarocladium plant pathogen and an endophyte.

RESULTS

In this study, we reported a gapless genome sequence of a newly identified endophytic fungus Sarocladium brachiariae isolated from Brachiaria brizantha. The genome of S. brachiariae is 31.86 Mb, with a contig N50 of 3.27 Mb and 9903 protein coding genes. Phylogenomic analysis based on single copy orthologous genes provided insights into the evolutionary relationships of S. brachiariae and its closest species was identified as S. oryzae. Comparative genomics analysis revealed that S. brachiaria has 14.9% more plant cell wall degradation related CAZymes to S. oryzae, and 33.3% more fungal cell wall degradation related CAZymes, which could explain the antifungal activity of S. brachiaria. Based on Antibiotics & Secondary Metabolite Analysis Shell (antiSMASH) analysis, we identified a contact helvolic acid biosynthetic gene cluster (BGC) for the first time in S. oryzae. However, S. brachiaria had seven fewer terpene gene clusters, including helvolic acid BGC, compared with S. oryzae and this may be associated with adaptation to an endophytic lifestyle. Synteny analysis of polyketide synthases (PKS), non-ribosomal peptide synthetases (NRPS), and hybrid (PKS-NRPS) gene clusters between S. brachiariae and S. oryzae revealed that just 37.5% of tested clusters have good synteny, while 63.5% have no or poor synteny. This indicated that the S. brachiariae could potentially synthesize a variety of unknown-function secondary metabolites, which may play an important role in adaptation to its endophytic lifestyle and antifungal activity.

CONCLUSIONS

The data provided a better understanding of the Sarocladium brachiariae genome. Further comparative genomic analysis provided insight into the genomic basis of its endophytic lifestyle and antifungal activity.

The Many Facets of Tumor Heterogeneity: Is Metabolism Lagging Behind?

Tumor functional heterogeneity has been recognized for decades, and technological advancements are fueling renewed interest in uncovering the cell-intrinsic and extrinsic factors that influence tumor development and therapeutic response. Intratumoral heterogeneity is now arguably one of the most-studied topics in tumor biology, leading to the discovery of new paradigms and reinterpretation of old ones, as we aim to understand the profound implications that genomic, epigenomic, and functional heterogeneity hold with regard to clinical outcomes. In spite of our improved understanding of the biological complexity of cancer, characterization of tumor metabolic heterogeneity has lagged behind, lost in a century-old controversy debating whether glycolysis or mitochondrial respiration is more influential. But is tumor metabolism really so simple? Here, we review historical and current views of intratumoral heterogeneity, with an emphasis on summarizing the emerging data that begin to illuminate just how vast the spectrum of metabolic strategies a tumor can employ may be, and what this means for how we might interpret other tumor characteristics, such as mutational landscape, contribution of microenvironmental influences, and treatment resistance.

Circulating serum fatty acid synthase is elevated in patients with diabetes and carotid artery stenosis and is LDL-associated

BACKGROUND AND AIMS

Diabetes is an independent risk factor for carotid artery stenosis (CAS). Fatty acid synthase (FAS), an essential de novo lipogenesis enzyme, has increased activity in the setting of diabetes that leads to altered lipid metabolism. Circulating FAS (cFAS) was recently observed in the blood of patients with hyperinsulinemia and cancer. We thought to evaluate the origin of cFAS and its role in diabetes-associated CAS.

METHODS

Patients with diabetes and no diabetes, undergoing carotid endarterectomy (CEA) for CAS, were prospectively enrolled for collection of plaque and fasting serum. FPLC was used to purify lipoprotein fractions, and ELISA was used to quantify cFAS content and activity. Immunoprecipitation (IP) was used to evaluate the affinity of cFAS to LDL-ApoB.

RESULTS

Patients with CAS had higher cFAS activity (p < 0.01), and patients with diabetes had higher cFAS activity than patients with no diabetes (p < 0.05). cFAS activity correlated with serum glucose (p = 0.03, r² = 0.35), and cFAS content trended with plaque FAS content (p = 0.06, r² = 0.69). cFAS was predominantly in LDL cholesterol fractions of patients with CAS (p < 0.001), and IP of cFAS demonstrated pulldown of ApoB. Similar to patients with diabetes, db/db mice had highest levels of serum cFAS (p < 0.01), and fasL^-/- (tissue-specific liver knockdown of FAS) mice had the lowest levels of cFAS (p < 0.001).

CONCLUSIONS

Serum cFAS is higher in patients with diabetes and CAS, appears to originate from the liver, and is LDL cholesterol associated. We postulate that LDL may be serving as a carrier for cFAS that contributes to atheroprogression in carotid arteries of patients with diabetes.

Corn dried distillers grains with solubles (cDDGS) in the diet of pigs change the expression of adipose genes that are potential therapeutic targets in metabolic and cardiovascular diseases

Background

Corn dried distillers grains with solubles (cDDGS) are a byproduct of biofuel and alcohol production. cDDGS have been used in pig feed for many years, because they are readily available and rich in protein, fiber, unsaturated fatty acids and phytosterols. However, feed mixtures too high in cDDGS result in the worsening of backfat quality. We performed RNA-sequencing analysis of backfat from crossbred pigs fed different diets. The diets were isoenergetic but contained different amounts of cDDGS and various sources of fats. The animals were divided into four dietary groups during the two months of experimentation: group I (control (-cDDGS+rapeseed oil)), group II (+cDDGS+rapeseed oil), group III (+cDDGS+beef tallow), and group IV (+cDDGS+coconut oil). The aim of the present experiment was to evaluate changes in the backfat transcriptome of pigs fed isoenergetic diets that differed in cDDGS presence.

Results

Via DESeq2 software, we identified 93 differentially expressed genes (DEGs) between groups I and II, 13 between groups I and III, and 125 between groups I and IV. DEGs identified between group I (-cDDGS+rapeseed oil) and group II (+cDDGS+rapeseed oil) were highly overrepresented in several KEGG pathways: metabolic pathways (FDR < 1.21e-06), oxidative phosphorylation (FDR < 0.00189), fatty acid biosynthesis (FDR < 0.00577), Huntington’s disease (FDR < 0.00577), fatty acid metabolism (FDR < 0.0112), Parkinson’s disease (FDR < 0.0151), non-alcoholic fatty liver disease (NAFLD) (FDR < 0.016), Alzheimer’s disease (FDR < 0.0211) and complement and coagulation cascades (FDR < 0.02).

Conclusions

We observed that the addition of cDDGS positively affects the expression of several genes that have been recently proposed as potential targets for the treatment of obesity, diabetes, cardiovascular disease, and Alzheimer’s disease (e.g., FASN, AACS, ALAS1, HMGCS1, and VSIG4). Thus, our results support the idea of including cDDGS into the diets of companion animals and humans and encourage research into the bioactive ingredients of cDDGS.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-5265-x) contains supplementary material, which is available to authorized users.

Targeting Cancer with Phytochemicals via Their Fine Tuning of the Cell Survival Signaling Pathways

The role of phytochemicals as potential prodrugs or therapeutic substances against tumors has come in the spotlight in the very recent years, thanks to the huge mass of encouraging and promising results of the in vitro activity of many phenolic compounds from plant raw extracts against many cancer cell lines. Little but important evidence can be retrieved from the clinical and nutritional scientific literature, where flavonoids are investigated as major pro-apoptotic and anti-metastatic compounds. However, the actual role of these compounds in cancer is still far to be fully elucidated. Many of these phytochemicals act in a pleiotropic and poorly specific manner, but, more importantly, they are able to tune the reactive oxygen species (ROS) signaling to activate a survival or a pro-autophagic and pro-apoptosis mechanism, depending on the oxidative stress-responsive endowment of the targeted cell. This review will try to focus on this issue.

Targeting Tumor Metabolism with Plant-Derived Natural Products: Emerging Trends in Cancer Therapy

Recognition of neoplastic metabolic reprogramming as one of cancer's hallmarks has paved the way for developing novel metabolism-targeted therapeutic approaches. The use of plant-derived natural bioactive compounds for this endeavor is especially promising, due to their diverse structures and multiple targets. Hence, over the past decade, a growing number of studies have assessed the impact of phytochemicals on tumor cell metabolism, aiming at improving current knowledge on their mechanisms of action and, at the same time, evaluating their potential as anti-cancer metabolic modulators. In this Review, we focus on three classes of plant-derived compounds with promising anti-cancer activity-phenolic compounds, isoprenoids, and alkaloids-to describe their effects on major energetic and biosynthetic pathways of human tumor cells. Such a comprehensive and integrated account of the ability of these compounds to hit different metabolic targets is expected to contribute to the rational design and critical assessment of novel anti-cancer therapies based on natural-product-mediated metabolic reprogramming.

Heat shock protein 70 promotes lipogenesis in HepG2 cells

Background

The increasing prevalence of non-alcoholic fatty liver disease (NAFLD) has followed the international rise in obesity rates. Multiple mechanisms are involved in NAFLD, including endoplasmic reticulum stress and oxidative stress. Heat shock protein 70 (HSP70), which is abundant in most organisms, is sensitive to stress. However, the role of HSP70 in NAFLD has not been investigated. Here, we investigated the possible role of HSP70 in lipid synthesis.

Methods

C57BL/6 mice were fed a high-fat diet, and HepG2 cells were treated with 0.5 mM palmitic acid (PA). HSP70 expression was detected by qPCR, Western blot and immunohistochemistry. Total cholesterol (TC) and triglyceride (TG) levels were detected by enzyme-linked immunosorbent assay (ELISA). After Hsp70 overexpression and knockdown, TC and TG levels and FAS, SCD, and ACC expression were detected.

Results

HSP70 expression was significantly increased in the livers of obese mice. In vitro, HSP70 expression was markedly induced by PA in HepG2 cells. Notably, HSP70 overexpression in HepG2 cells enhanced TC and TG synthesis, in parallel with the upregulation of lipogenic genes, including FAS, SCD and ACC. By contrast, HSP70 knockdown decreased the levels of cellular lipids and the expression of FAS, SCD, and ACC in HepG2 cells. Together, our results suggest that HSP70 may promote lipogenesis in HepG2 cells.

Conclusions

Heat shock protein 70 promotes lipogenesis in HepG2 cells.

Deciphering metabolic rewiring in breast cancer subtypes

Metabolic reprogramming, an emerging hallmark of cancer, is observed in breast cancer. Breast cancer cells rewire their cellular metabolism to meet the demands of survival, proliferation, and invasion. However, breast cancer is a heterogeneous disease, and metabolic rewiring is not uniform. Each subtype of breast cancer displays distinct metabolic alterations. Here, we focus on unique metabolic reprogramming associated with subtypes of breast cancer, as well as common features. Therapeutic opportunities based on subtype-specific metabolic alterations are also discussed. Through this discussion, we aim to provide insight into subtype-specific metabolic rewiring and vulnerabilities that have the potential to better guide therapy and improve outcomes for patients.

Crystal structure of FabZ-ACP complex reveals a dynamic seesaw-like catalytic mechanism of dehydratase in fatty acid biosynthesis

Fatty acid biosynthesis (FAS) is a vital process in cells. Fatty acids are essential for cell assembly and cellular metabolism. Abnormal FAS directly correlates with cell growth delay and human diseases, such as metabolic syndromes and various cancers. The FAS system utilizes an acyl carrier protein (ACP) as a transporter to stabilize and shuttle the growing fatty acid chain throughout enzymatic modules for stepwise catalysis. Studying the interactions between enzymatic modules and ACP is, therefore, critical for understanding the biological function of the FAS system. However, the information remains unclear due to the high flexibility of ACP and its weak interaction with enzymatic modules. We present here a 2.55 Å crystal structure of type II FAS dehydratase FabZ in complex with holo-ACP, which exhibits a highly symmetrical FabZ hexamer-ACP3 stoichiometry with each ACP binding to a FabZ dimer subunit. Further structural analysis, together with biophysical and computational results, reveals a novel dynamic seesaw-like ACP binding and catalysis mechanism for the dehydratase module in the FAS system, which is regulated by a critical gatekeeper residue (Tyr100 in FabZ) that manipulates the movements of the β-sheet layer. These findings improve the general understanding of the dehydration process in the FAS system and will potentially facilitate drug and therapeutic design for diseases associated with abnormalities in FAS.