Blockade of fatty acid synthase triggers significant apoptosis in mantle cell lymphoma

Leveraging altered lipid metabolism in treating B cell malignancies

B cell malignancies, comprising over 80 heterogeneous blood cancers, pose significant prognostic challenges due to intricate oncogenic signaling. Emerging evidence emphasizes the pivotal role of disrupted lipid metabolism in the development of these malignancies. Variations in lipid species, such as phospholipids, cholesterol, sphingolipids, and fatty acids, are widespread across B cell malignancies, contributing to uncontrolled cell proliferation and survival. Phospholipids play a crucial role in initial signaling cascades leading to B cell activation and malignant transformation through constitutive B cell receptor (BCR) signaling. Dysregulated cholesterol and sphingolipid homeostasis support lipid raft integrity, crucial for propagating oncogenic signals. Sphingolipids impact malignant B cell stemness, proliferation, and survival, while glycosphingolipids in lipid rafts modulate BCR activation. Additionally, cancer cells enhance fatty acid-related processes to meet heightened metabolic demands. In obese individuals, the obesity-derived lipids and adipokines surrounding adipocytes rewire lipid metabolism in malignant B cells, evading cytotoxic therapies. Genetic drivers such as MYC translocations also intrinsically alter lipid metabolism in malignant B cells. In summary, intrinsic and extrinsic factors converge to reprogram lipid metabolism, fostering aggressive phenotypes in B cell malignancies. Therefore, targeting altered lipid metabolism has translational potential for improving risk stratification and clinical management of diverse B cell malignancy subtypes.

High dietary Fructose Drives Metabolic Dysfunction-Associated Steatotic Liver Disease via Activating ubiquitin-specific peptidase 2/11β-hydroxysteroid dehydrogenase type 1 Pathway in Mice

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common cause of chronic liver-related morbidity and mortality. Though high fructose intake is acknowledged as a metabolic hazard, its role in the etiology of MASLD requires further clarification. Here, we demonstrated that high dietary fructose drives MASLD development and promotes MASLD progression in mice, and identified Usp2 as a fructose-responsive gene in the liver. Elevated USP2 levels were detected in the hepatocytes of MASLD mice; a similar increase was observed following fructose exposure in primary hepatocytes and mouse AML12 cells. Notably, hepatocytes overexpressing USP2 presented with exaggerated lipid accumulation and metabolic inflammation when exposed to fructose. Conversely, USP2 knockdown mitigated these fructose-induced changes. Furthermore, USP2 was found to activate the C/EBPα/11β-HSD1 signaling, which further impacted the equilibrium of cortisol and cortisone in the circulation of mice. Collectively, our findings revealed the role of dietary fructose in MASLD pathogenesis and identified the USP2-mediated C/EBPα/ 11β-HSD1 signaling as a potential target for the management of MASLD.

Oxidative Stress and Inflammation in B-Cell Lymphomas

Mature lymphoid neoplasms arise de novo or by the transformation of more indolent lymphomas in a process that relies on the stepwise accumulation of genomic and transcriptomic alterations. The microenvironment and neoplastic precursor cells are heavily influenced by pro-inflammatory signaling, regulated in part by oxidative stress and inflammation. Reactive oxygen species (ROSs) are by-products of cellular metabolism able to modulate cell signaling and fate. Moreover, they play a crucial role in the phagocyte system, which is responsible for antigen presentation and the selection of mature B and T cells under normal conditions. Imbalances in pro-oxidant and antioxidant signaling can lead to physiological dysfunction and disease development by disrupting metabolic processes and cell signaling. This narrative review aims to analyze the impact of reactive oxygen species on lymphomagenesis, specifically examining the regulation of microenvironmental players, as well as the response to therapy for B-cell-derived non-Hodgkin lymphomas. Further research is needed to investigate the involvement of ROS and inflammation in the development of lymphomas, which may unravel disease mechanisms and identify innovative therapeutic targets.

Metabolic Reprogramming and Potential Therapeutic Targets in Lymphoma

Lymphoma is a heterogeneous group of diseases that often require their metabolism program to fulfill the demand of cell proliferation. Features of metabolism in lymphoma cells include high glucose uptake, deregulated expression of enzymes related to glycolysis, dual capacity for glycolytic and oxidative metabolism, elevated glutamine metabolism, and fatty acid synthesis. These aberrant metabolic changes lead to tumorigenesis, disease progression, and resistance to lymphoma chemotherapy. This metabolic reprogramming, including glucose, nucleic acid, fatty acid, and amino acid metabolism, is a dynamic process caused not only by genetic and epigenetic changes, but also by changes in the microenvironment affected by viral infections. Notably, some critical metabolic enzymes and metabolites may play vital roles in lymphomagenesis and progression. Recent studies have uncovered that metabolic pathways might have clinical impacts on the diagnosis, characterization, and treatment of lymphoma subtypes. However, determining the clinical relevance of biomarkers and therapeutic targets related to lymphoma metabolism is still challenging. In this review, we systematically summarize current studies on metabolism reprogramming in lymphoma, and we mainly focus on disorders of glucose, amino acids, and lipid metabolisms, as well as dysregulation of molecules in metabolic pathways, oncometabolites, and potential metabolic biomarkers. We then discuss strategies directly or indirectly for those potential therapeutic targets. Finally, we prospect the future directions of lymphoma treatment on metabolic reprogramming.

Current Status of Novel Agents for the Treatment of B Cell Malignancies: What's Coming Next?

Resistance to death is one of the hallmarks of human B cell malignancies and often contributes to the lack of a lasting response to today's commonly used treatments. Drug discovery approaches designed to activate the death machinery have generated a large number of inhibitors of anti-apoptotic proteins from the B-cell lymphoma/leukemia 2 family and the B-cell receptor (BCR) signaling pathway. Orally administered small-molecule inhibitors of Bcl-2 protein and BCR partners (e.g., Bruton's tyrosine kinase and phosphatidylinositol-3 kinase) have already been included (as monotherapies or combination therapies) in the standard of care for selected B cell malignancies. Agonistic monoclonal antibodies and their derivatives (antibody-drug conjugates, antibody-radioisotope conjugates, bispecific T cell engagers, and chimeric antigen receptor-modified T cells) targeting tumor-associated antigens (TAAs, such as CD19, CD20, CD22, and CD38) are indicated for treatment (as monotherapies or combination therapies) of patients with B cell tumors. However, given that some patients are either refractory to current therapies or relapse after treatment, novel therapeutic strategies are needed. Here, we review current strategies for managing B cell malignancies, with a focus on the ongoing clinical development of more effective, selective drugs targeting these molecules, as well as other TAAs and signaling proteins. The observed impact of metabolic reprogramming on B cell pathophysiology highlights the promise of targeting metabolic checkpoints in the treatment of these disorders.

Druggable Metabolic Vulnerabilities Are Exposed and Masked during Progression to Castration Resistant Prostate Cancer

There is an urgent need for exploring new actionable targets other than androgen receptor to improve outcome from lethal castration-resistant prostate cancer. Tumor metabolism has reemerged as a hallmark of cancer that drives and supports oncogenesis. In this regard, it is important to understand the relationship between distinctive metabolic features, androgen receptor signaling, genetic drivers in prostate cancer, and the tumor microenvironment (symbiotic and competitive metabolic interactions) to identify metabolic vulnerabilities. We explore the links between metabolism and gene regulation, and thus the unique metabolic signatures that define the malignant phenotypes at given stages of prostate tumor progression. We also provide an overview of current metabolism-based pharmacological strategies to be developed or repurposed for metabolism-based therapeutics for castration-resistant prostate cancer.

Concomitant Inhibition of FASN and SREBP Provides a Promising Therapy for CTCL

Simple Summary

The biosynthesis of fatty acids catalysed by FASN plays an important oncogenic role in various malignancies but has not been reported in CTCL yet. Here, we show that FASN is highly expressed in both cell lines and primary cells from CTCL patients. The inhibition of FASN impairs cell viability, survival, and proliferation. FASN expression is partly controlled by SREBP, and dual inhibition of FASN and SREBP enhances the impairment of cell proliferation. Overall, our data suggest that the combination of FASN and SREBP inhibitors could be a promising novel strategy in CTCL therapy.

Abstract

Cutaneous T cell lymphoma (CTCL) is a group of non-Hodgkin’s primary cutaneous T cell lymphomas, with Mycosis Fungoides and Sézary syndrome (SS) being the two most common subtypes. Fatty acid synthase (FASN) is a crucial enzyme that catalyses the biosynthesis of fatty acids, which has been reported to play an oncogenic role in various malignancies but not in CTCL so far. Herein, we show that FASN is highly expressed in CTCL cell lines and in peripheral blood mononuclear cells (PBMCs) from CTCL patients, while it is not in PBMCs from healthy individuals. The inhibition of FASN in CTCL cell lines impairs cell viability, survival, and proliferation, but, interestingly, it also increases FASN expression. However, inhibiting sterol regulatory element binding protein (SREBP), a transcription factor that promotes the expression of FASN, partially reversed the upregulation of FASN induced by FASN inhibitors. Thus, the combination of FASN and SREBP inhibitors enhanced the effects on both CTCL cell lines and PBMCs from SS patients, where a valid inhibition on cell proliferation could be verified. Importantly, compared to non-malignant cells, primary malignant cells are more sensitive to the inhibition of FASN and SREBP, making the combination of FASN and SREBP inhibitors a promising novel therapeutic strategy in CTCL.

Fatty acid metabolism in aggressive B-cell lymphoma is inhibited by tetraspanin CD37

The importance of fatty acid (FA) metabolism in cancer is well-established, yet the mechanisms underlying metabolic reprogramming remain elusive. Here, we identify tetraspanin CD37, a prognostic marker for aggressive B-cell lymphoma, as essential membrane-localized inhibitor of FA metabolism. Deletion of CD37 on lymphoma cells results in increased FA oxidation shown by functional assays and metabolomics. Furthermore, CD37-negative lymphomas selectively deplete palmitate from serum in mouse studies. Mechanistically, CD37 inhibits the FA transporter FATP1 through molecular interaction. Consequently, deletion of CD37 induces uptake and processing of exogenous palmitate into energy and essential building blocks for proliferation, and inhibition of FATP1 reverses this phenotype. Large lipid deposits and intracellular lipid droplets are observed in CD37-negative lymphoma tissues of patients. Moreover, inhibition of carnitine palmitoyl transferase 1 A significantly compromises viability and proliferation of CD37-deficient lymphomas. Collectively, our results identify CD37 as a direct gatekeeper of the FA metabolic switch in aggressive B-cell lymphoma.

Tetraspanin CD37 deficiency has been reported as a prognostic marker for aggressive B-cell lymphoma. Here, the authors show that CD37 interacts with the fatty acid transporter 1 to inhibit palmitate uptake and its deficiency leads to increased fatty acid metabolism which promotes tumorigenesis in B-cell lymphoma.

Reprogramming lipid metabolism as potential strategy for hematological malignancy therapy

Hematological malignancies are one of the most lethal illnesses that seriously threaten human life and health. Lipids are important constituents of various biological membranes and substances for energy storage and cell signaling. Furthermore, lipids are critical in the normal physiological activities of cells. In the process of the lethal transformation of hematological malignancies, lipid metabolism reprogramming meets the material and energy requirements of rapidly proliferating and dividing tumor cells. A large number of studies have shown that dysregulated lipid metabolism, commonly occurs in hematological malignancies, mediating the proliferation, growth, migration, invasion, apoptosis, drug resistance and immune escape of tumor cells. Targeting the lipid metabolism pathway of hematological malignancies has become an effective therapeutic approach. This article reviews the oncogenic mechanisms of lipid metabolism reprogramming in hematological malignancies, including fatty acid, cholesterol and phospholipid metabolism, thereby offering an insight into targeting lipid metabolism in the treatment of hematological malignancies.

Antiphospholipid Antibodies and Lipids in Hematological Malignancies

One of the main groups of lipids is phospholipids, which are mainly involved in forming cell membranes. Neoplastic processes such as cell replication have increased lipid synthesis, making tumor cells dependent on this synthesis to maintain their requirements. Antiphospholipid antibodies attack phospholipids in the cell membranes. Three main types of antiphospholipid antibodies are recognized: anti-β2 glycoprotein I (anti-β2GP-I), anticardiolipin (aCL), and lupus anticoagulant (LA). These types of antibodies have been proven to be present in hematological neoplasms, particularly in LH and NHL. This review on antiphospholipid antibodies in hematological neoplasms describes their clinical relationship as future implications at the prognostic level for survival and even treatment.

Distinct BTK inhibitors differentially induce apoptosis but similarly suppress chemotaxis and lipid accumulation in mantle cell lymphoma

Background

The more selective second-generation BTK inhibitors (BTKi) Acalabrutinib and Zanubrutinib and the first-generation BTKi Ibrutinib are highlighted by their clinical effectiveness in mantle cell lymphoma (MCL), however, similarities and differences of their biological and molecular effects on anti-survival of MCL cells induced by these BTKi with distinct binding selectivity against BTK remain largely unknown.

Methods

AlamarBlue assays were performed to define cytotoxicity of BTKi against MCL cells, Jeko-1 and Mino. Cleaved PARP and caspase-3 levels were examined by immunoblot analysis to study BTKi-induced apoptotic effects. Biological effects of BTKi on MCL-cell chemotaxis and lipid droplet (LD) accumulation were examined in Jeko-1, Mino and primary MCL cells via Transwell and Stimulated Raman scattering imaging analysis respectively. Enzyme-linked immunoassays were used to determine CCL3 and CCL4 levels in MCL-cell culture supernatants. RNA-seq analyses identified BTKi targets which were validated by quantitative RT-PCR (qRT-PCR) and immunoblot analysis.

Results

Acalabrutinib and Zanubrutinib induced moderate apoptosis in Ibrutinib high-sensitive JeKo-1 cells and Ibrutinib low-sensitive Mino cells, which was accompanied by cleaved PARP and caspase-3. Such effects might be caused by the stronger ability of Ibrutinib to upregulate the expression of pro-apoptotic genes, such as HRK, GADD45A, and ATM, in JeKo-1 cells than in Mino cells, and the expression of such apoptotic genes was slightly changed by Acalabrutinib and Zanubrutinib in both JeKo-1 and Mino cells. Further, Acalabrutinib, Zanubrutinib and Ibrutinib reduced MCL-cell chemotaxis with similar efficiency, due to their similar abilities to downmodulate chemokines, such as CCL3 and CCL4. Also, these three BTKi similarly suppressed MCL-cell LD accumulation via downregulating lipogenic factors, DGAT2, SCD, ENPP2 and ACACA without significant differences.

Conclusion

BTKi demonstrated differential capacities to induce MCL-cell apoptosis due to their distinct capabilities to regulate the expression of apoptosis-related genes, and similar biological and molecular inhibitory effects on MCL-cell chemotaxis and LD accumulation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08475-3.

The Heterogeneity of Lipid Metabolism in Cancer

The study of cancer cell metabolism has traditionally focused on glycolysis and glutaminolysis. However, lipidomic technologies have matured considerably over the last decade and broadened our understanding of how lipid metabolism is relevant to cancer biology [1-3]. Studies now suggest that the reprogramming of cellular lipid metabolism contributes directly to malignant transformation and progression [4, 5]. For example, de novo lipid synthesis can supply proliferating tumor cells with phospholipid components that comprise the plasma and organelle membranes of new daughter cells [6, 7]. Moreover, the upregulation of mitochondrial β-oxidation can support tumor cell energetics and redox homeostasis [8], while lipid-derived messengers can regulate major signaling pathways or coordinate immunosuppressive mechanisms [9-11]. Lipid metabolism has, therefore, become implicated in a variety of oncogenic processes, including metastatic colonization, drug resistance, and cell differentiation [10, 12-16]. However, whether we can safely and effectively modulate the underlying mechanisms of lipid metabolism for cancer therapy is still an open question.

First-in-human study of the safety, pharmacokinetics, and pharmacodynamics of first-in-class fatty acid synthase inhibitor TVB-2640 alone and with a taxane in advanced tumors

BACKGROUND

We conducted a first-in-human dose-escalation study with the oral FASN inhibitor TVB-2640 to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D), as monotherapy and with a taxane.

METHODS

This completed open-label outpatient study was conducted at 11 sites in the United States and United Kingdom. Patients with previously-treated advanced metastatic solid tumors and adequate performance status and organ function were eligible. TVB-2640 was administered orally daily until PD. Dose escalation initially followed an accelerated titration design that switched to a standard 3 + 3 design after Grade 2 toxicity occurred. Disease-specific cohorts were enrolled at the MTD. Statistical analyses were primarily descriptive. Safety analyses were performed on patients who received at least 1 dose of study drug. (Clinicaltrials.gov identifier NCT02223247).

FINDINGS

The study was conducted from 21 November 2013 to 07 February 2017. Overall, 136 patients received TVB-2640, 76 as monotherapy (weight-based doses of 60 mg/m² to 240 mg/m² and flat doses of 200 and 250 mg) and 60 in combination, (weight-based doses of 60 mg/m² to 100 mg/m² and flat dose of 200 mg) (55 paclitaxel, 5 docetaxel). DLTs with TVB-2640 were reversible skin and ocular effects. The MTD/RP2D was 100 mg/m². The most common TEAEs (n,%) with TVB-2640 monotherapy were alopecia (46; 61%), PPE syndrome (35; 46%), fatigue (28; 37%), decreased appetite (20; 26%), and dry skin (17; 22%), and with TVB-2640+paclitaxel were fatigue (29 ; 53%), alopecia (25; 46%), PPE syndrome (25; 46%), nausea (22; 40%), and peripheral neuropathy (20; 36%). One fatal case of drug-related pneumonitis occurred with TVB-2640+paclitaxel; no other treatment-related deaths occurred. Target engagement (FASN inhibition) and inhibition of lipogenesis were demonstrated with TVB-2640. The disease control rate (DCR) with TVB-2640 monotherapy was 42%; no patient treated with monotherapy had a complete or partial response (CR or PR). In combination with paclitaxel, the PR rate was 11% and the DCR was 70%. Responses were seen across multiple tumor types, including in patients with KRAS^MUT NSCLC, ovarian, and breast cancer.

INTERPRETATION

TVB-2640 demonstrated potent FASN inhibition and a predictable and manageable safety profile, primarily characterized by non-serious, reversible adverse events affecting skin and eyes. Further investigation of TVB-2640 in patients with solid tumors, particularly in KRAS^MUT lung, ovarian, and breast cancer, is warranted.

FUNDING

This trial was funded by 3-V Biosciences, Inc. (now known as Sagimet Biosciences Inc.).

Upregulation of fatty acid synthase in MYC and BCL-2 double-expressor lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common and heterogeneous lymphoid malignancy. The subtype with MYC and BCL-2 double-expressor lymphoma (DEL) was defined by its aggressive nature and poor survival outcome. Therefore, the development of effective therapies for the DEL subtype is imperative. Fatty acid synthase (FASN) activity is associated with altered lipid metabolism and aberrant protein translation in DLBCL. However, the inter-regulation of these key processes is not fully determined in DEL. In the present study, the clinical and biological impact of FASN was investigated in the DEL subtype. Initially, FASN expression levels were analyzed from a patient cohort and the data indicated that the highest FASN expression was noted in DEL tissues compared with that noted in the DLBCL and reactive lymphoid hyperplasia tissues. Patients with DEL with combined high-FASN expression indicated poorer EFS outcomes than the rest of the patients. In vitro data indicated that FASN was overexpressed in SU-DHL-2 and U2932 cells. Silencing FASN decreased cell growth and promoted cell apoptosis by modulating the pERK/BCL-2 signaling pathway. In conclusion, the present study indicated that FASN was overexpressed in DEL and that its expression was associated with poor survival outcomes. Furthermore, the data demonstrated that FASN regulated the biological function via the pERK/BCL-2 signaling pathway. FASN serves a critical role in the progression of DEL and its expression may be associated with the development to a more aggressive phenotype of DLBCL. Therefore, it may be considered a potential therapeutic target for DLBCL.

USP2-Related Cellular Signaling and Consequent Pathophysiological Outcomes

Ubiquitin specific protease (USP) 2 is a multifunctional deubiquitinating enzyme. USP2 modulates cell cycle progression, and therefore carcinogenesis, via the deubiquitination of cyclins and Aurora-A. Other tumorigenic molecules, including epidermal growth factor and fatty acid synthase, are also targets for USP2. USP2 additionally prevents p53 signaling. On the other hand, USP2 functions as a key component of the CLOCK/BMAL1 complex and participates in rhythmic gene expression in the suprachiasmatic nucleus and liver. USP2 variants influence energy metabolism by controlling hepatic gluconeogenesis, hepatic cholesterol uptake, adipose tissue inflammation, and subsequent systemic insulin sensitivity. USP2 also has the potential to promote surface expression of ion channels in renal and intestinal epithelial cells. In addition to modifying the production of cytokines in immune cells, USP2 also modulates the signaling molecules that are involved in cytokine signaling in the target cells. Usp2 knockout mice exhibit changes in locomotion and male fertility, which suggest roles for USP2 in the central nervous system and male genital tract, respectively. In this review, we summarize the cellular events with USP2 contributions and list the signaling molecules that are upstream or downstream of USP2. Additionally, we describe phenotypic differences found in the in vitro and in vivo experimental models.

Fatty Acid Synthase: An Emerging Target in Cancer

In recent years, lipid metabolism has garnered significant attention as it provides the necessary building blocks required to sustain tumor growth and serves as an alternative fuel source for ATP generation. Fatty acid synthase (FASN) functions as a central regulator of lipid metabolism and plays a critical role in the growth and survival of tumors with lipogenic phenotypes. Accumulating evidence has shown that it is capable of rewiring tumor cells for greater energy flexibility to attain their high energy requirements. This multi-enzyme protein is capable of modulating the function of subcellular organelles for optimal function under different conditions. Apart from lipid metabolism, FASN has functional roles in other cellular processes such as glycolysis and amino acid metabolism. These pivotal roles of FASN in lipid metabolism make it an attractive target in the clinic with several new inhibitors currently being tested in early clinical trials. This article aims to present the current evidence on the emergence of FASN as a target in human malignancies.

Function and regulation of lipid signaling in lymphomagenesis: A novel target in cancer research and therapy

To survive under the challenging conditions, cancer cells adapt their own metabolic mechanism(s) to be able steady supplying energy and metabolites for synthesis of new biomass. Aberrant lipid metabolism in cancer cells becomes a hall marker of carcinogenesis. Epidemiologic evidence indicates that fat intake, in particular saturated or animal fat, may increase the risk of lymphoma. Understanding the specific alterations of lymphoma metabolism becomes essential to address malignant transformation, progression, and therapeutic approaches. This review is focused on the lipid metabolism, with emphasis on fatty acid synthase, lipid rafts, exosomes, and metabolic diseases, in distinct lymphoma entities.

Lipids and cancer: Emerging roles in pathogenesis, diagnosis and therapeutic intervention

With the advent of effective tools to study lipids, including mass spectrometry-based lipidomics, lipids are emerging as central players in cancer biology. Lipids function as essential building blocks for membranes, serve as fuel to drive energy-demanding processes and play a key role as signaling molecules and as regulators of numerous cellular functions. Not unexpectedly, cancer cells, as well as other cell types in the tumor microenvironment, exploit various ways to acquire lipids and extensively rewire their metabolism as part of a plastic and context-dependent metabolic reprogramming that is driven by both oncogenic and environmental cues. The resulting changes in the fate and composition of lipids help cancer cells to thrive in a changing microenvironment by supporting key oncogenic functions and cancer hallmarks, including cellular energetics, promoting feedforward oncogenic signaling, resisting oxidative and other stresses, regulating intercellular communication and immune responses. Supported by the close connection between altered lipid metabolism and the pathogenic process, specific lipid profiles are emerging as unique disease biomarkers, with diagnostic, prognostic and predictive potential. Multiple preclinical studies illustrate the translational promise of exploiting lipid metabolism in cancer, and critically, have shown context dependent actionable vulnerabilities that can be rationally targeted, particularly in combinatorial approaches. Moreover, lipids themselves can be used as membrane disrupting agents or as key components of nanocarriers of various therapeutics. With a number of preclinical compounds and strategies that are approaching clinical trials, we are at the doorstep of exploiting a hitherto underappreciated hallmark of cancer and promising target in the oncologist's strategy to combat cancer.

Inhibition of FASN suppresses the malignant biological behavior of non-small cell lung cancer cells via deregulating glucose metabolism and AKT/ERK pathway

Background

Fatty acid synthase (FASN) is overexpressed in most human carcinomas, including non-small cell lung cancer (NSCLC), and contributes to poor prognosis. An increasing number of studies have highlighted the potential function of FASN as both a biomarker and therapeutic target for cancers. However, the underlying molecular mechanisms of FASN in glucose metabolism and the malignant biological behavior of NSCLC remain the subjects of intensive investigation.

Methods

FASN expression was depleted by FASN-siRNA in A549 and NCI-H1299 cell lines to detect the function of glucose metabolism and the malignant biological behavior of NSCLC cells. Western-blot and qPCR were applied to determine the expressions of FASN, t-AKT, p-AKT, t-ERK, p-ERK, PKM2, HK2 and AZGP1. ATP and lactate were detected to determine the activation of glucose metabolism. CCK8 and transwell assays were used to detect the proliferation, invasion, and migration capacity of the two types of NSCLC cells. The xenograft mouse model was used to evaluate tumor weights after suppression of FASN.

Results

LV-FASN-siRNA and its control lentiviral vector were successfully transfected into the two types of NSCLC cells (A549 and NCI-H1299). LV-FASN siRNA significantly suppressed FASN expression in both NSCLC cell types, and expressions of p-AKT, p-ERK, PKM2, and AZGP1 were also significantly decreased. Notably, the levels of ATP and lactate were significantly decreased after transfection with LV-FASN siRNA. The proliferation of both NSCLC cell types was decreased after suppression of FASN. The invasion and migration capacity of A549, but not NCI-H1299, were inhibited following down-regulation of FASN. In vivo, inhibition of FASN caused a marked animal tumor weight loss.

Conclusions

FASN was involved in glucose metabolism via down-regulation of the AKT/ERK pathway and eventually altered the malignant phenotype in lung cancer cells.

The peculiarities of cancer cell metabolism: A route to metastasization and a target for therapy

The last decade has witnessed the peculiarities of metabolic reprogramming in tumour onset and progression, and their relevance in cancer therapy. Also, it has been indicated that the metastatic process may depend on the metabolic rewiring and adaptation of cancer cells to the pressure of tumour microenvironment and limiting nutrient availability. The present review gatherers the existent knowledge on the influence of tumour microenvironment and metabolic routes driving metastasis. A focus will be given to glycolysis, fatty acid metabolism, glutaminolysis, and amino acid handling. In addition, the role of metabolic waste driving metastasization will be explored. Finally, we discuss the status of cancer treatment approaches targeting metabolism. This knowledge revision will highlight the critical metabolic targets in metastasis and the chemicals already used in preclinical studies and clinical trials, providing clues that would be further exploited in medicinal chemistry research.

Orlistat induces apoptosis and protective autophagy in ovarian cancer cells: involvement of Akt-mTOR-mediated signaling pathway

INTRODUCTION

Orlistat possesses anti-tumor capacity by inducing apoptosis in ovarian cancer cells. However, the mechanism is not clearly understood. Emerging evidence indicates the overlaps between autophagy and apoptosis. In this study, we have investigated the role of autophagy in orlistat-induced apoptosis in ovarian cancer (OC) cells.

METHODS

The effect of orlistat on apoptosis was evaluated in SKOV3 and A2780 cell lines by MTT and TUNEL assay. The formations of autophagosomes were observed by acridine orange and GFP-LC3 fluorescence. In addition, conversions of LC3-I to LC3-II were analyzed by western blot, as well as other autophagy-related proteins. 3-Methyladenine (3-MA) was used as an autophagy inhibitor in combined treatment with orlistat. Western blot was further conducted to investigate the molecular mechanisms of orlistat-affected apoptosis and autophagy on protein level.

RESULTS

The proliferation activities of OC cells were inhibited by orlistat in a dose-dependent manner. The expressions of cleaved-caspase 3 and 9 in orlistat-treated cells were increasing, which suggested that orlistat-induced apoptosis was caspase-dependent. At the same time, the average number of GFP-LC3 dots per cell was increased after 48 h of orlistat treatment. The expression levels of LC3-II were significantly up-regulated, as well as other autophagy-related proteins such as Vsp34, Atg7 and UVRAG. These results suggested orlistat-induced autophagy flux, which was further found involved in inhibiting the Akt/mTOR/p70S6K signaling pathway. However, combined treatment of orlistat and 3-MA significantly suppressed the cell viability, which indicated a pro-survival role of autophagy in OC cells.

CONCLUSION

We suggested that orlistat had anti-cancer effect in OC cells. In addition, autophagy played a pro-survival role, suppressing which the orlistat-induced anti-cancer effect would be more significant.

Orlistat as a FASN inhibitor and multitargeted agent for cancer therapy

INTRODUCTION

Cancer cells have increased glycolysis and glutaminolysis. Their third feature is increased de novo lipogenesis. As such, fatty acid (FA) synthesis enzymes are over-expressed in cancer and their depletion causes antitumor effects. As fatty acid synthase (FASN) plays a pivotal role in this process, it is an attractive target for cancer therapy.

AREAS COVERED

This is a review of the lipogenic phenotype of cancer and how this phenomenon can be exploited for cancer therapy using inhibitors of FASN, with particular emphasis on orlistat as a repurposing drug.

EXPERT OPINION

Disease stabilization only has been observed with a highly selective FASN inhibitor used as a single agent in clinical trials. It is too early to say whether the absence of tumor responses other than stabilization results because even full inhibition of FASN is not enough to elicit antitumor responses. The FASN inhibitor orlistat is a 'dirty' drug with target-off actions upon at least seven targets with a proven role in tumor biology. The development of orlistat formulations suited for its intravenous administration is a step ahead to shed light on the concept that drug promiscuity can or not be a virtue.

Retigabine ameliorates acute stress-induced impairment of spatial memory retrieval through regulating USP2 signaling pathways in hippocampal CA1 area

Acute stress could trigger maladaptive changes associated with stress-related cognitive and emotional deficits. Dysfunction of ion channel or receptor in the hippocampal area has been linked to the cognitive deficits induced by stress. It is known that Kv7 channel openers, including FDA-approved drug retigabine, show cognitive protective efficacy. However, the underlying molecular mechanisms remain elusive. Here we showed that exposing adult male rats to acute stress significantly impaired the spatial memory, a cognitive process controlled by the hippocampus. Concomitantly, significantly reduced AMPA receptor expression was found in hippocampal CA1 area from acute stressed rats. This effect relied on the down-regulation of deubiquitinating enzyme USP2 and its upstream regulators (PGC-1α and β-catenin), and the subsequent enhancement of mTOR-related autophagy which is regulated by USP2. These findings suggested that acute stress dampened AMPA receptor expression by controlling USP2-related signaling, which caused the detrimental effect on hippocampus-dependent cognitive processes. We also found that retigabine alleviated acute stress-induced spatial memory retrieval impairment through adjusting the aberrance of USP2, its upstream regulators (PGC-1α, E4BP4 and β-catenin) and its downstream targets (mTOR, autophagy and GluA1). Our results have identified USP2 as a key molecule that mediates stress-induced spatial memory retrieval impairment, which provides a framework for new druggable targets to conceptually treat stress-associated cognitive deficits.

Recent advances in targeting the fatty acid biosynthetic pathway using fatty acid synthase inhibitors

INTRODUCTION

Elevated lipogenesis has been associated with a variety of diseases including obesity, cancer and nonalcoholic fatty liver disease (NAFLD). Fatty acid synthase (FASN) plays a pivotal role in de novo lipogenesis, making this multi-catalytic protein an attractive target for therapeutic intervention. Recently, the first FASN inhibitor successfully advanced through the drug development process and entered clinical evaluation in oncology. Areas covered: This review discusses the biological roles of FASN in three prominent disease areas: cancer, obesity-related disorders and NAFLD. Recent advances in drug discovery strategies and design of newer FASN inhibitors are also highlighted. Expert opinion: Despite the abundance of evidence linking the lipogenic pathway to cancer, progression of FASN-targeted molecules has been rather slow and challenging and no compounds have moved past the preclinical phase. The landscape has recently changed with the recent advancement of the first FASN inhibitor into clinical evaluation for solid tumors. Needless to say, the successful translation into the clinical setting will open opportunities for expanding the therapeutic utility of FASN inhibitors not just in oncology but in other diseases associated with elevated lipogenesis such as obesity, type 2 diabetes, and NAFLD.

Metabolic Regulation of Apoptosis in Cancer

Apoptosis is a cellular suicide program that plays a critical role in development and human diseases, including cancer. Cancer cells evade apoptosis, thereby enabling excessive proliferation, survival under hypoxic conditions, and acquired resistance to therapeutic agents. Among various mechanisms that contribute to the evasion of apoptosis in cancer, metabolism is emerging as one of the key factors. Cellular metabolites can regulate functions of pro- and antiapoptotic proteins. In turn, p53, a regulator of apoptosis, also controls metabolism by limiting glycolysis and facilitating mitochondrial respiration. Consequently, with dysregulated metabolism and p53 inactivation, cancer cells are well-equipped to disable the apoptotic machinery. In this article, we review how cellular apoptosis is regulated and how metabolism can influence the signaling pathways leading to apoptosis, especially focusing on how glucose and lipid metabolism are altered in cancer cells and how these alterations can impact the apoptotic pathways.

Global gene deregulations in FASN silenced retinoblastoma cancer cells: molecular and clinico-pathological correlations

Activation of fatty acid synthase (FASN) enzyme in the de novo lipogenic pathway has been reported in various cancers including retinoblastoma (RB), a pediatric ocular cancer. The present study investigates lipogenesis-dependent survival of RB cancer cells and the associated molecular pathways in FASN silenced RB cells. The siRNA-mediated FASN gene knockdown in RB cancer cells (Y79, WERI RB1) repressed FASN mRNA and protein expressions, and decreased cancer cell viability. Global gene expression microarray analysis was performed in optimized FASN siRNA transfected and untransfected RB cells. Deregulation of various downstream cell signaling pathways such as EGFR (n = 55 genes), TGF-beta (n = 45 genes), cell cycle (n = 41 genes), MAPK (n = 39 genes), lipid metabolism (n = 23 genes), apoptosis (n = 21 genes), GPCR signaling (n = 21 genes), and oxidative phosporylation (n = 18 genes) were observed. The qRT-PCR validation in FASN knockdown RB cells revealed up-regulation of ANXA1, DAPK2, and down-regulation of SKP2, SREBP1c, RXRA, ACACB, FASN, HMGCR, USP2a genes that favored the anti-cancer effect of lipogenic inhibition in RB. The expression of these genes in primary RB tumor tissues were correlated with FASN expression, based on their clinico-pathological features. The differential phosphorylation status of the various PI3K/AKT pathway proteins (by western analysis) indicated that the FASN gene silencing indeed mediated apoptosis in RB cells through the PI3K/AKT pathway. Scratch assay clearly revealed that FASN silencing reduced the invading property of RB cancer cells. Dependence of RB cancer cells on lipid metabolism for survival and progression is implicated. Thus targeting FASN is a promising strategy in RB therapy.

A Cellular Assay for Inhibitors of the Fatty Acid Biosynthetic Pathway Using Scintillating Microplates

A simplified method for monitoring the incorporation of radiolabeled acetate into lipids in a cellular system is described. The assay eliminates the commonly employed labor-intensive organic extraction step by plating the cells in 96-well tissue culture-treated ScintiPlates(®) that enable direct measurement of radiolabeled cell membrane-embedded lipids. Since the scintillant is entrenched in the plates, radioactivity in close proximity to the scintillant is measured without the need for liquid scintillation cocktail. The utility of this method for evaluating inhibitors of the de novo fatty acid synthetic pathway is demonstrated here with fatty acid synthase (FASN). Due to the upregulation of FASN activity in many tumor types, development of inhibitors to block the FASN activity in cells shows promise as an attractive and tractable approach for therapeutic intervention.

Regulation of lipid synthesis by the RNA helicase Mov10 controls Wnt5a production

Expression of the Wnt ligand Wnt5a is frequently elevated in melanoma and is thought to be a critical regulator of cell movement during metastasis. However, the mechanisms regulating its expression are unknown. We find that the level of secreted Wnt5a varies by as much as 10-fold between cell lines and correlates more strongly with invasion than total cellular levels. Our results indicate that the RNA helicase Mov10 plays a role in Wnt5a synthesis and secretion. Inhibition of Mov10 increases secreted Wnt5a levels in melanoma cells by increasing Wnt5a synthesis and acylation. This is achieved by increasing fatty acid synthase (FASN) and stearoyl-CoA desaturase expression, leading to elevated levels of palmitoleoyl-CoA, required for Wnt ligand lipid modification and secretion. Melanoma tumors exhibit reduced expression of Mov10 compared with benign nevi and Mov10 levels inversely correlate with FASN levels in primary tumors. These results reveal a previously unappreciated role for aberrant lipid metabolism in regulating Wnt5a signaling that may be a critical step in melanoma progression.

AMACR amplification in myxofibrosarcomas: a mechanism of overexpression that promotes cell proliferation with therapeutic relevance

PURPOSE

Myxofibrosarcomas frequently display arm-level gains on 5p. We characterized the pathogenetic and therapeutic relevance of the α-methylacyl coenzyme A racemase (AMACR) at 5p13.3.

EXPERIMENTAL DESIGN

AMACR mRNA expression in myxofibrosarcomas was analyzed using the public transcriptome and laser-microdissected sarcoma cells. We performed florescence in situ hybridization (FISH) and immunohistochemistry in independent samples for clinical correlates. In AMACR-overexpressing myxofibrosarcoma cells and xenografts, we elucidated the biologic function of AMACR using RNA interference and explored the therapeutic effect and mechanism of an AMACR inhibitor, ebselen oxide.

RESULTS

AMACR protein overexpression and gene amplification were significantly associated with each other (P < 0.001), with higher tumor grades (both P ≤ 0.002), and univariately with worse metastasis-free survival (MFS; both P < 0.0001) and disease-specific survival (DSS; P = 0.0002 for overexpression; P = 0.0062 for amplification). AMACR protein overexpression also independently portended adverse outcome (DSS, P = 0.007; MFS, P = 0.001). However, 39% of AMACR-overexpression cases did not show gene amplification, implying alternative regulatory mechanisms. In myxofibrosarcoma cell lines, stable AMACR knockdown suppressed cell proliferation, anchorage-independent growth, and expression of cyclin D1 and cyclin T2. These growth-promoting attributes of AMACR were corroborated in the AMACR-silenced xenograft model and AMACR-underexpressed myxofibrosarcomas, showing decreased labeling for cyclin D1, cyclin T2, and Ki-67. Compared with fibroblasts, AMACR-expressing myxofibrosarcoma cells were more susceptible to ebselen oxide, which not only decreased viable cells, promoted proteasome-mediated degradation of AMACR protein, and induced cellular apoptosis in vitro, but also dose-dependently suppressed xenografted tumor growth in vivo.

CONCLUSIONS

Overexpressed AMACR in myxofibrosarcomas can be amplification-driven, associated with tumor aggressiveness, and may be relevant as a druggable target.

The selective target of capsaicin on FASN expression and de novo fatty acid synthesis mediated through ROS generation triggers apoptosis in HepG2 cells

The inhibition of the mammalian de novo synthesis of long-chain saturated fatty acids (LCFAs) by blocking the fatty acid synthase (FASN) enzyme activity in tumor cells that overexpress FASN can promote apoptosis, without apparent cytotoxic to non-tumor cells. The present study aimed to focus on the potent inhibitory effect of capsaicin on the fatty acid synthesis pathway inducing apoptosis of capsaicin in HepG2 cells. The use of capsaicin as a source for a new FASN inhibitor will provide new insight into its possible application as a selective anti-cancer therapy. The present findings showed that capsaicin promoted apoptosis as well as cell cycle arrest in the G0/G1 phase. The onset of apoptosis was correlated with a dissipation of mitochondrial membrane potential (ΔΨm). Apoptotic induction by capsaicin was mediated by inhibition of FASN protein expression which was accompanied by decreasing its activity on the de novo fatty acid synthesis. The expression of FASN was higher in HepG2 cells than in normal hepatocytes that were resistant to undergoing apoptosis following capsaicin administration. Moreover, the inhibitory effect of capsaicin on FASN expression and activity was found to be mediated by an increase of intracellular reactive oxygen species (ROS) generation. Treatment of HepG2 cells with capsaicin failed to alter ACC and ACLY protein expression, suggesting ACC and ACLY might not be the specific targets of capsaicin to induce apoptosis. An accumulation of malonyl-CoA level following FASN inhibition represented a major cause of mitochondrial-dependent apoptotic induction instead of deprivation of fatty acid per se. Here, we also obtained similar results with C75 that exhibited apoptosis induction by reducing the levels of fatty acid without any change in the abundance of FASN expression along with increasing ROS production. Collectively, our results provide novel evidence that capsaicin exhibits a potent anti-cancer property by targeting FASN protein in HepG2 cells.

Profiling of serum metabolites in canine lymphoma using gas chromatography mass spectrometry

Canine lymphoma is a common cancer that has high rates of complete remission with combination chemotherapy. However, the duration of remission varies based on multiple factors, and there is a need to develop a method for early detection of recurrence. In this study, we compared the metabolites profiles in serum from 21 dogs with lymphoma and 13 healthy dogs using gas chromatography mass spectrometry (GC-MS). The lymphoma group was separated from the control group in an orthogonal projection to latent structure with discriminant analysis (OPLS-DA) plot using ions of m/z 100-600, indicating that the metabolites profiles in lymphoma cases differed from those in healthy dogs. The lymphoma group was also separated from the control group on OPLS-DA plot using 29 metabolites identified in all serum samples. Significant differences were found for 16 of these metabolites with higher levels in the lymphoma group for 15 of the metabolites and lower levels for inositol. An OPLS-DA plot showed separation of the lymphoma and healthy groups using these 16 metabolites only. These results indicate that metabolites profile with GC-MS may be a useful tool for detection of potential biomarker and diagnosis of canine lymphoma.

Risk factors for etiology and prognosis of mantle cell lymphoma

Non-Hodgkin lymphomas (NHLs) include any kind of lymphoma except Hodgkin's lymphoma. Mantle cell lymphoma (MCL) is a B-cell NHL and it accounts for about 6% of all NHL cases. Its epidemiologic and clinical features, as well as biomarkers, can differ from those of other NHL subtypes. This article first provides a very brief description of MCL's epidemiology and clinical features. For etiology and prognosis separately, we review clinical, environmental, and molecular risk factors that have been suggested in the literature. Among a large number of potential risk factors, only a few have been independently validated, and their clinical utilization has been limited. More data need to be accumulated and effectively analyzed before clinically useful risk factors can be identified and used for prevention, diagnosis, prediction of prognosis path, and treatment selection.

Discrepant NOXA (PMAIP1) transcript and NOXA protein levels: a potential Achilles' heel in mantle cell lymphoma

Mantle cell lymphoma (MCL) is an aggressive lymphoid neoplasm with transient response to conventional chemotherapy. We here investigated the role of the Bcl-2 homology domain 3-only protein NOXA for life–death decision in MCL. Surprisingly, NOXA (PMAIP1) mRNA and NOXA protein levels were extremely discrepant in MCL cells: NOXA mRNA was found to be highly expressed whereas NOXA protein levels were low. Chronic active B-cell receptor signaling and to a minor degree cyclin D1 overexpression contributed to high NOXA mRNA expression levels in MCL cells. The phoshatidyl-inositol-3 kinase/AKT/mammalian target of rapamycin pathway was identified as the major downstream signaling pathway involved in the maintenance of NOXA gene expression. Interestingly, MCL cells adapt to this constitutive pro-apoptotic signal by extensive ubiquitination and rapid proteasomal degradation of NOXA protein (T_½∼15–30 min). In addition to the proteasome inhibitor Bortezomib, we identified the neddylation inhibitor MLN4924 and the fatty acid synthase inhibitor Orlistat as potent inducers of NOXA protein expression leading to apoptosis in MCL. All inhibitors targeted NOXA protein turnover. In contrast to Bortezomib, MLN4924 and Orlistat interfered with the ubiquitination process of NOXA protein thereby offering new strategies to kill Bortezomib-resistant MCL cells. Our data, therefore, highlight a critical role of NOXA in the balance between life and death in MCL. The discrepancy between NOXA transcript and protein levels is essential for sensitivity of MCL to ubiquitin-proteasome system inhibitors and could therefore provide a druggable Achilles' heel of MCL cells.

The role of adipose tissue and obesity in causing treatment resistance of acute lymphoblastic leukemia

Obesity is responsible for ~90,000 cancer deaths/year, increasing cancer incidence and impairing its treatment. Obesity has also been shown to impact hematological malignancies, through as yet unknown mechanisms. Adipocytes are present in bone marrow and the microenvironments of many types of cancer, and have been found to promote cancer cell survival. In this review, we explore several ways in which obesity might cause leukemia treatment resistance. Obese patients may be at a treatment disadvantage due to altered pharmacokinetics of chemotherapy and dosage "capping" based on ideal body weight. The adipose tissue provides fuel to cancer cells in the form of amino acids and free fatty acids. Adipocytes have been shown to cause cancer cells to resist chemotherapy-induced apoptosis. In addition, obese adipose tissue is phenotypically altered, producing a milieu of pro-inflammatory adipokines and cytokines, some of which have been linked to cancer progression. Given the prevalence of obesity, understanding its role and adipose tissue in acute lymphoblastic leukemia treatment is necessary for evaluating current treatment regimen and revealing new therapeutic targets.

The fatty acid synthase inhibitor orlistat reduces the growth and metastasis of orthotopic tongue oral squamous cell carcinomas

Fatty acid synthase (FASN) is the biosynthetic enzyme responsible for the endogenous synthesis of fatty acids. It is downregulated in most normal cells, except in lipogenic tissues such as liver, lactating breast, fetal lung, and adipose tissue. Conversely, several human cancers, including head and neck squamous cell carcinomas (HNSCC), overexpress FASN, which has been associated with poor prognosis and recently suggested as a metabolic oncoprotein. Orlistat is an irreversible inhibitor of FASN activity with cytotoxic properties on several cancer cell lines that inhibits tumor progression and metastasis in prostate cancer xenografts and experimental melanomas, respectively. To explore whether the inhibition of FASN could impact oral tongue squamous cell carcinoma (OTSCC) metastatic spread, an orthotopic model was developed by the implantation of SCC-9 ZsGreen LN-1 cells into the tongue of BALB/c nude mice. These cells were isolated through in vivo selection, show a more invasive behavior in vitro than the parental cells, and generate orthotopic tumors that spontaneously metastasize to cervical lymph nodes in 10 to 15 days only. SCC-9 ZsGreen LN-1 cells also exhibit enhanced production of MMP-2, ERBB2, and CDH2. The treatment with orlistat reduced proliferation and migration, promoted apoptosis, and stimulated the secretion of VEGFA165b by SCC-9 ZsGreen LN-1 cells. In vivo, the drug was able to decrease both the volume and proliferation indexes of the tongue orthotopic tumors and, importantly, reduced the number of metastatic cervical lymph nodes by 43%. These results suggest that FASN is a potential molecular target for the chemotherapy of patients with OTSCC.

The PPARα agonist fenofibrate suppresses B-cell lymphoma in mice by modulating lipid metabolism

Obesity is associated with an increased risk for malignant lymphoma development. We used Bcr/Abl transformed B cells to determine the impact of aggressive lymphoma formation on systemic lipid mobilization and turnover. In wild-type mice, tumor size significantly correlated with depletion of white adipose tissues (WAT), resulting in increased serum free fatty acid (FFA) concentrations which promote B-cell proliferation in vitro. Moreover, B-cell tumor development induced hepatic lipid accumulation due to enhanced hepatic fatty acid (FA) uptake and impaired FA oxidation. Serum triglyceride, FFA, phospholipid and cholesterol levels were significantly elevated. Consistently, serum VLDL/LDL-cholesterol and apolipoprotein B levels were drastically increased. These findings suggest that B-cell tumors trigger systemic lipid mobilization from WAT to the liver and increase VLDL/LDL release from the liver to promote tumor growth. Further support for this concept stems from experiments where we used the peroxisome proliferator-activated receptor α (PPARα) agonist and lipid-lowering drug fenofibrate that significantly suppressed tumor growth independent of angiogenesis and inflammation. In addition to WAT depletion, fenofibrate further stimulated FFA uptake by the liver and restored hepatic FA oxidation capacity, thereby accelerating the clearance of lipids released from WAT. Furthermore, fenofibrate blocked hepatic lipid release induced by the tumors. In contrast, lipid utilization in the tumor tissue itself was not increased by fenofibrate which correlates with extremely low expression levels of PPARα in B-cells. Our data show that fenofibrate associated effects on hepatic lipid metabolism and deprivation of serum lipids are capable to suppress B-cell lymphoma growth which may direct novel treatment strategies. This article is part of a Special Issue entitled Lipid Metabolism in Cancer.

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B-cell lymphoma induced WAT loss and elevated serum FFA.

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B-cell lymphoma caused increased liver mass and FA uptake, impaired hepatic FA oxidation and enhanced hepatic lipid export.

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Fenofibrate reduced lymphoma induced elevation of serum FA by increasing hepatic FA uptake and oxidation.

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Fenofibrate blocks hepatic lipid export as triglyceride-rich VLDL or cholesterol-rich LDL in B-cell lymphoma bearing mice.

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Fenofibrate suppresses B-cell lymphoma in mice.

FASN and CD36 predict survival in rituximab-treated diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma is the most common lymphoid malignancy, as it accounts for approximately one third of all patient cases of non-Hodgkin's lymphoma. Patients with diffuse large B-cell lymphoma have markedly different treatment outcomes, suggesting a need for reliable prognostic factors and novel therapeutic approaches. De novo fatty acid synthesis is an important metabolic driver of tumor in multiple malignancies. In this retrospective study, we analyzed expression of fatty acid synthase (a key enzyme in de novo fatty acid synthesis), Spot 14 (thyroid hormone responsive Spot 14, a nuclear protein that promotes expression of genes involved in fatty acid synthesis), and CD36 (the cell surface channel for exogenous fatty acid uptake) in patients with diffuse large B-cell lymphoma and their clinical significance. We observed that overexpression of fatty acid synthase is negatively associated with overall survival (p=0.001) and progression-free period (p=0.004) in patients with diffuse large B-cell lymphoma. Multivariate analysis showed that fatty acid synthase overexpression is an independent prognostic marker of aggressive clinical course. For the first time, we report CD36 as an independent protective factor in patients treated with rituximab. Thus, fatty acid synthase and CD36 expression may serve as prognostic markers to predict response to treatment and survival in diffuse large B-cell lymphoma patients. Fatty acid synthase may also be a potential therapeutic target in lymphoid malignancies.