C75 Treatment Research Articles

Serum Metabolomic Profile in Hypoxia-Induced Pulmonary Hypertension Mice after C75 Treatment.

Inhibition of fatty acid synthase (FAS) plays a crucial protective role in pulmonary hypertension (PH). Our aim was to identify novel metabolites in mice with hypoxia-induced PH after treatment with C75 (FAS inhibitor) and to confirm the presence of these metabolites in paediatric patients with PH. The PH mouse model was built by chronic hypoxia and ovalbumin (OVA) assistance. Untargeted metabolomics was used to analyse mouse serum. Six children with PH and six relative controls (patients without lung and heart disease) were selected in Shanghai Children's Hospital and they all performed blood tandem mass spectrometry during hospitalization. First, a total of 29 differential metabolites, including lipid metabolites, polyamine, and glutamine were identified as differential metabolites in the hypoxia group compared with the control group. After C75 treatment, symptoms were partially relieved in the PH mouse, and 15 differential metabolites, including lipid metabolites, polyamine, and glutamine were identified in the hypoxia + C75 group compared with the hypoxia group. These differential metabolites were enriched in arginine and glycerolipid metabolism through metabolite set enrichment analyses and were involved in excessive cell proliferation, which was a characteristic of PH. Second, glutamine and caproyl carnitine levels were increased in paediatric patients with PH. FAS may be a potential PH therapeutic target. Lipid metabolites, polyamine, and glutamine, are closely related to PH. Putrescine and glutamine might be biomarkers for PH.

Comparative transcription profiling of mRNA and lncRNA in pulmonary arterial hypertension after C75 treatment

ObjectivesTo investigate mRNA and long non-coding RNA (lncRNA) expression profiles in monocrotaline (MCT)- mice.Materials and methodsLung tissues (Control-Vehicle, MCT-Vehicle, and MCT-C75) were examined by high-throughput sequencing (HTS). Aberrantly expressed mRNAs and lncRNAs were analyzed by bioinformatics. Cell proliferation and cell cycle analysis were performed to detect the potential protective effects of C75, an inhibitor of fatty acid synthase. The signaling pathways associated with inflammatory responses were verified by real time-PCR.ResultsRNA sequencing data reveals 285 differentially expressed genes (DEGs) and 147 lncRNAs in the MCT-Vehicle group compared to the control. After five-week of C75 treatment, 514 DEGs and 84 lncRNAs are aberrant compared to the MCT-Vehicle group. Analysis of DEGs and lncRNA target genes reveals that they were enriched in pathways related to cell cycle, cell division, and vascular smooth muscle contraction that contributes to the PAH pathological process. Subsequently, the expression of eight DEGs and three lncRNAs is verified using RT-PCR. Differentially expressed lncRNAs (ENSMUSG00000110393.2, Gm38850, ENSMUSG00000100465.1, ENSMUSG00000110399.1) may associate in PAH pathogenesis as suggested by co-expression network analysis. C75 can protect against MCT-induced PAH through its anti-inflammatory and anti-proliferation.ConclusionsThese DEGs and lncRNAs can be considered as novel candidate regulators of PAH pathogenesis. We propose that C75 treatment can partially reverse PAH pathogenesis through modulating cell cycle, cell proliferation, and anti-inflammatory.

The Emerging Role of Fatty Acid Synthase in Hypoxia-Induced Pulmonary Hypertensive Mouse Energy Metabolism.

Aims This study is aimed at examining whether fatty acid synthase (FAS) can regulate mitochondrial function in hypoxia-induced pulmonary arterial hypertension (PAH) and its related mechanism. Results The expression of FAS significantly increased in the lung tissue of mice with hypoxia-induced PAH, and its pharmacological inhibition by C75 ameliorated right ventricle cardiac function as revealed by echocardiographic analysis. Based on transmission electron microscopy and Seahorse assays, the mitochondrial function of mice with hypoxia was abnormal but was partially reversed after C75 injection. In vitro studies also showed an increase in the expression of FAS in hypoxia-induced human pulmonary artery smooth muscle cells (HPASMCs), which could be attenuated by FAS shRNA as well as C75 treatment. Meanwhile, C75 treatment reversed hypoxia-induced oxidative stress and activated PI3K/AKT signaling. shRNA-mediated inhibition of FAS reduced its expression and oxidative stress levels and improved mitochondrial respiratory capacity and ATP levels of hypoxia-induced HPASMCs. Conclusions Inhibition of FAS plays a crucial role in shielding mice from hypoxia-induced PAH, which was partially achieved through the activation of PI3K/AKT signaling, indicating that the inhibition of FAS may provide a potential future direction for reversing PAH in humans.

Fatty Acid Synthase Contributes to Restimulation-Induced Cell Death of Human CD4 T Cells.

Restimulation-induced cell death (RICD) is an apoptotic pathway triggered in activated effector T cells after T cell receptor (TCR) re-engagement. RICD operates at the peak of the immune response to ensure T cell expansion remains in check to maintain immune homeostasis. Understanding the biochemical regulation of RICD sensitivity may provide strategies for tuning the magnitude of an effector T cell response. Metabolic reprogramming in activated T cells is not only critical for T cell differentiation and effector functions, but also influences apoptosis sensitivity. We previously demonstrated that aerobic glycolysis correlates with optimum RICD sensitivity in human effector CD8 T cells. However, metabolic programming in CD4 T cells has not been investigated in this context. We employed a pharmacological approach to explore the effects of fatty acid and glycolytic metabolism on RICD sensitivity in primary human CD4 T cells. Blockade of fatty acid synthase (FASN) with the compound C75 significantly protected CD4 effector T cells from RICD, suggesting that fatty acid biosynthesis contributes to RICD sensitivity. Interestingly, sphingolipid synthesis and fatty acid oxidation (FAO) were dispensable for RICD. Disruption of glycolysis did not protect CD4 T cells from RICD unless glyceraldehyde-3-phosphate dehydrogenase (GAPDH) enzymatic activity was targeted specifically, highlighting important differences in the metabolic control of RICD in effector CD4 vs. CD8 T cell populations. Moreover, C75 treatment protected effector CD4 T cells derived from naïve, effector memory, and central memory T cell subsets. Decreased RICD in C75-treated CD4 T cells correlated with markedly reduced FAS ligand (FASL) induction and a Th2-skewed phenotype, consistent with RICD-resistant CD4 T cells. These findings highlight FASN as a critical metabolic potentiator of RICD in human effector CD4 T cells.

FASN activity is important for the initial stages of the induction of senescence

Senescent cells accumulate in several tissues during ageing and contribute to several pathological processes such as ageing and cancer. Senescence induction is a complex process not well defined yet and is characterized by a series of molecular changes acquired after an initial growth arrest. We found that fatty acid synthase (FASN) levels increase during the induction of senescence in mouse hepatic stellate cells and human primary fibroblasts. Importantly, we also observed a significant increase in FASN levels during ageing in mouse liver tissues. To probe the central role of FASN in senescence induction, we used a small-molecule inhibitor of FASN activity, C75. We found that C75 treatment prevented the induction of senescence in mouse and human senescent cells. Importantly, C75 also reduced the expression of the signature SASP factors interleukin 1α (IL-1α), IL-1β and IL-6, and suppressed the secretion of small extracellular vesicles. These findings were confirmed using a shRNA targeting FASN. In addition, we find that FASN inhibition induces metabolic changes in senescent cells. Our work underscores the importance of C75 as a pharmacological inhibitor for reducing the impact of senescent cell accumulation.

Inhibition of TGF-β induced lipid droplets switches M2 macrophages to M1 phenotype

Lipid droplets (LD) are newly characterized dynamic cytoplasmic organelle which is the storehouse of different immunosuppressive cytokines and enzymes like cyclooxygenase and lipoxygenase. Tumors are known to modulate the immune system by immune-editing the microenvironment. Immuno-editing comprises of three steps namely cancer immune-surveillance, tumor dormancy and finally escape leading to tumor development. The latency of the tumor microenvironment is greatly contributed by the M2 polarized macrophages and TGF-β is a prime culprit. Modulating M2 macrophages to M1 can be a strategy against tumor progression. We found that tumor-conditioned medium or recombinant TGF-β was efficient to induce LD formation in Raw264.7 cells and the inhibition of LD was associated with the switch of M2 to M1 phenotype involving MEK1/2 axis. Signature molecules of M2 polarized macrophages like CD206 were also downregulated while co-stimulatory molecules like CD80, CD86 were up-regulated along with enhanced surface expression of MHCII when these macrophages were subjected to C75 treatment to reduce the LD formation. The level of pro-inflammatory cytokine, as well as ROS and NO generation, were also increased when TGF-β treated macrophages were subjected to C75 treatment. This study is probably the first report of this kind and can be used in the future in cancer treatment.

Abstract 4455: Fatty acid synthase-induced S6Kinase facilitates USP11-eIF4B complex formation for sustained oncogenic translation in DLBCL

Abstract Fatty acid synthase (FASN) and protein translational machinery are two emergent therapeutic targets for cancer treatment, but their mutual dependency on each other for tumor propagation especially in diffuse B-cell large lymphoma (DLBCL) is still unknown. Therefore, we investigated the functional implication of enhanced FASN activity on protein translational machinery employing a panel of 7 DLCBL cell lines and 40 clinical samples. Inhibition of FASN activity by a specific inhibitor, C75 or shRNA mediated knockdown, suppressed de novo protein synthesis in SUDHL2, TMD8, Pfeiffer and HLY-1 (ABC-origin) cells, whereas SUDHL4, SUDHL6 and Toledo (GC-origin) cells showed minimal effect after C75 treatment or FASN knockdown. Assessing the core translational machinery, the eIF4B (eukaryotic initiation factor 4B) levels were depleted in a dose dependent manner of C75 treatment or shRNA mediated knock down of FASN in ABC-DLBCLs. Mechanistically, eIF4B undergoes ubiquitin mediated protein degradation upon FASN depletion. Depleting the expression of eIF4B significantly reduced the proliferative capacity of both FASN sensitive as well resistant DLBCL cells. Screening the interacting protein partners from available databases, we observed that USP11 interacts with and deubiquitinates eIF4B increasing its overall stability. Consistently, altering the expression of USP11 or its activity by either chemical inhibition or mutation significantly alters nascent peptide synthesis. Of functional significance, either down regulating USP11 or inhibition via small molecules significantly reduced the cell proliferation with increased apoptosis of both, FASN activity sensitive and resistant DLBCL cells. USP11 expression was also elevated in DLBCL tissues as evidenced by significantly higher staining. Significantly there is a strong correlation between USP11, FASN as well as eIF4B expression in DLBCL. Elucidating the basis for FASN not regulating GC DLBCL, we observed that sustained PI3K signalling in GC-DLBCL plays a key role in FASN dependent eIF4B stability. Detailed molecular analysis established that S6Kinase phosphorylates USP11 at Ser453, which regulates its interaction with, and stability of eIF4B thereby promoting proto-oncogene expression. These results together demonstrate that FASN activated S6Kinase induced eIF4B/USP11 axis is required for cell proliferation and survival by regulating the translation of proliferative and pro-survival mRNAs. Our findings support targeting the eIF4B/USP11 axis and provide a novel therapeutic option for patients with relapsed/refractory DLBCL. Citation Format: Bandish Kapadia, Nahid Nanaji, Kavita Bhalla, Binny Bhandary, Rena Lapidus, Afshin Beheshti, Andrew Evens, Ronald Gartenhaus. Fatty acid synthase-induced S6Kinase facilitates USP11-eIF4B complex formation for sustained oncogenic translation in DLBCL [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4455.

Abstract A33: Understanding the functional role of enhanced FASN activity in regulating protein translation in DLCBL

Abstract Fatty acid synthase (FASN) and protein translational machinery are two emerging cancer therapeutic targets, but their mutual dependency on each other for tumor growth especially in diffuse B-cell large lymphoma (DLBCL) is currently unknown. Therefore, we investigated the functional consequences of enhanced FASN activity on protein translational machinery in both DLCBL cell lines as well as primary samples. Inhibition of FASN activity by a specific inhibitor, C75 or shRNA mediated knockdown, suppressed de novo protein synthesis in SUDHL2, Pfeiffer, and HLY-1 cells, whereas SUDHL4 and SUDHL6 cells displayed minimal impact. Assessing the core translational machinery, the eif4b (eukaryotic initiation factor 4b) levels were depleted in a dose dependent manner of C75 treatment or shRNA mediated knock down of FASN. Mechanistically, eif4b undergoes ubiquitin mediated protein degradation upon FASN depletion. Importantly there seems to be a direct correlation between FASN levels and eif4b expression in DLBCL samples. Depleting the expression of eif4b significantly reduced the cell proliferative capacity of both FASN sensitive as well as resistant DLBCL cells. Screening the interacting protein partners from the available databases, we observed that USP11 interacts and deubiquitinates eif4b which increases its overall stability. Furthermore altering the expression of USP11 or its activity by either chemical inhibition or mutations significantly alters nascent peptide synthesis. Significantly, either down regulating USP11 or inhibiting via small molecules significantly reduced the cell proliferation with increased apoptosis of either FASN activity sensitive or resistant DLBCL cells. USP11 expression was also elevated in DLBCL tissues. Importantly, there is a strong correlation between USP11 and FASN as well as eif4b expression in DLBCL with higher level of this proteins associated with poorer survival. Enhanced FASN activity increased the Akt kinase activity, which phosphorylates USP11 at an evolutionary conserved site. FASN stimulated Akt-meditated phosphorylation events is critical for USP11 recruitment on translational initiation machinery as well as interaction with eif4b to alter protein biosynthesis. These results demonstrate that FASN mediated eif4b/USP11 axis is required for cell proliferation and survival by regulating the translation of proliferative and prosurvival mRNAs. Targeting the eif4b/USP11 axis for therapeutic intervention may add additional treatment options for resistant/relapsed DLBCL patients. Citation Format: Bandish Kapadia, Ronald Gartenhaus. Understanding the functional role of enhanced FASN activity in regulating protein translation in DLCBL. [abstract]. In: Proceedings of the AACR Special Conference on Translational Control of Cancer: A New Frontier in Cancer Biology and Therapy; 2016 Oct 27-30; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2017;77(6 Suppl):Abstract nr A33.

Inhibitions of FASN suppress triglyceride synthesis via the control of malonyl-CoA in goat mammary epithelial cells

Fatty acid synthase (FASN) is the key enzyme for de novo fatty acid synthesis from acetyl-CoA and malonyl-CoA. All the steps involved in fatty acid synthesis by FASN have been clearly defined in monogastrics and ruminants. However, there are no data on the mechanism of how FASN affects triglyceride synthesis. Inhibition of FASN in goat mammary epithelial cells by C75, a synthetic inhibitor of FASN activity, and shRNA markedly suppressed the accumulation of triglyceride in goat mammary epithelial cells. Meanwhile, C75 treatment significantly reduced the relative content of monounsaturated fatty acids (C16:1 and C18:1). Corresponding to the suppression of lipid accumulation, both of C75 and shRNA also decreased the mRNA expression of GPAM, AGPAT6 and DGAT2, all of which are related to triglyceride synthesis. The fact that treatment of malonyl-CoA decreased the expression of these genes is consistent with the results of shRNA treatment. Furthermore, the supplement of malonyl-CoA enhanced the suppression on GPAM, AGPAT6, LPIN1, DGAT1 and DGAT2. The results underscore the role of malonyl-CoA in inhibition of FASN in regulating triglyceride synthesis in goat mammary epithelial cells.

Inhibition of Fatty Acid Synthase Sensitizes Prostate Cancer Cells to Radiotherapy.

Many common human cancers, including colon, prostate and breast cancer, express high levels of fatty acid synthase compared to normal human tissues. This elevated expression is associated with protection against apoptosis, increased metastasis and poor prognosis. Inhibitors of fatty acid synthase, such as the cerulenin synthetic analog C75, decrease prostate cancer cell proliferation, increase apoptosis and decrease tumor growth in experimental models. Although radiotherapy is widely used in the treatment of prostate cancer patients, the risk of damage to neighboring normal organs limits the radiation dose that can be delivered. In this study, we examined the potential of fatty acid synthase inhibition to sensitize prostate cancer cells to radiotherapy. The efficacy of C75 alone or in combination with X irradiation was examined in monolayers and in multicellular tumor spheroids. Treatment with C75 alone decreased clonogenic survival, an effect that was abrogated by the antioxidant. C75 treatment also delayed spheroid growth in a concentration-dependent manner. The radiosensitizing effect of C75 was indicated by combination index values between 0.65 and 0.71 and the reduced surviving fraction of clonogens, in response to 2 Gy X irradiation, from 0.51 to 0.30 and 0.11 in the presence of 25 and 35 μM C75, respectively. This increased sensitivity to radiation was reduced by the presence of the antioxidant. The C75 treatment also enhanced the spheroid growth delay induced by X irradiation in a supra-additive manner. The level of radiation-induced apoptosis in prostate cancer cells was increased further by C75, which induced cell cycle arrest in the G2/M phase, but only at a concentration greater than that required for radiosensitization. Radiation-induced G2/M blockade was not affected by C75 treatment. These results suggest the potential use of fatty acid synthase inhibition to enhance the efficacy of radiotherapy of prostate carcinoma and that C75-dependent cell cycle arrest is not responsible for its radiosensitizing effect.

Inhibition of fatty acid synthase with C75 decreases organ injury after hemorrhagic shock

Hemorrhagic shock is the primary cause of morbidity and mortality in the intensive care units in patients under the age of 35. Several organs, including the lungs, are seriously affected by hemorrhagic shock and inadequate resuscitation. Excess free fatty acids have shown to trigger inflammation in various disease conditions. C75 is a small compound that inhibits fatty acid synthase, a key enzyme in the control of fatty acid metabolism that also stimulates fatty acid oxidation. We hypothesized that C75 treatment would be protective against hemorrhagic shock. Adult male Sprague-Dawley rats were cannulated with a femoral artery catheter and subjected to controlled bleeding. Blood was shed to maintain a mean arterial pressure of 30mm Hg for 90minutes, then resuscitated over 30minutes with a crystalloid volume equal to twice the volume of shed blood. Fifteen minutes into the 30-minute resuscitation, the rats received either intravenous infusion of C75 (1mg/kg body weight) or vehicle (20% dimethyl sulfoxide). Blood and tissue samples were collected 6hours after resuscitation (ie, 7.5hours after hemorrhage) for analysis. After hemorrhage and resuscitation, C75 treatment decreased the increase in serum free fatty acids by 48%, restored adenosine triphosphate levels, and stimulated carnitine palmitoyl transferase-1 activity. Administration of C75 decreased serum levels of markers of injury (aspartate aminotransferase, lactate, and lactate dehydrogenase) by 38%, 32%, and 78%, respectively. Serum creatinine and blood urea nitrogen were also decreased significantly by 38% and 40%, respectively. These changes correlated with decreases in neutrophil infiltration in the lung, evidenced by decreases in Gr-1-stained cells and myeloperoxidase activity and improved lung histology. Finally, administration of C75 decreased pulmonary mRNA levels of cyclooxygenase-2 and interleukin-6 by 87% and 65%, respectively. Administration of C75 after hemorrhage and resuscitation decreased the increase in serum free fatty acids, decreased markers of tissue injury, downregulated the expression of inflammatory mediators, and decreased neutrophil infiltration and lung injury. Thus, the dual action of inhibiting fatty acid synthesis and stimulating fatty acid oxidation by C75 could be developed as a promising adjuvant therapy strategy to protect against hemorrhagic shock.

Inhibition of lipogenesis reduces inflammation and organ injury in sepsis

BackgroundSepsis is a life-threatening acute inflammatory condition associated with metabolic complications. Accumulation of free fatty acids (FFAs) induces inflammation and causes lipotoxic effects in the liver. Because fatty acid metabolism plays a role in the inflammatory response, we hypothesized that the administration of C75, a fatty acid synthase inhibitor, could alleviate the injury caused by sepsis. MethodsMale mice were subjected to sepsis by cecal ligation and puncture (CLP). At 4 h after CLP, different doses of C75 (1- or 5-mg/kg body weight) or vehicle (20% dimethyl sulfoxide in saline) were injected intraperitoneally. Blood and liver tissues were collected at 24 h after CLP. ResultsC75 treatment with 1- and 5-mg/kg body weight significantly lowered FFA levels in the liver after CLP by 28% and 53%, respectively. Administration of C75 dose dependently reduced serum indexes of organ injury (aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase) and serum levels of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6). In the liver, C75 treatment reduced inflammation (TNF-α and IL-6) and oxidative stress (inducible nitric oxide synthase and cyclooxygenase 2) in a dose-dependent manner. The 5-mg dose improved the 10-d survival rate to 85% from that of 55% in the vehicle. In the presence of C75, TNF-α release in RAW 246.7 cells with 4-h lipopolysaccharide stimulation was also significantly reduced. ConclusionsC75 effectively lowered FFA accumulation in the liver, which was associated with inhibition of inflammation and organ injury as well as improvement in survival rate after CLP. Thus, inhibition of FFA by C75 could ameliorate the hepatic dysfunction seen in sepsis.

4-Methylene-2-octyl-5-oxotetrahydrofuran-3-carboxylic Acid (C75), an Inhibitor of Fatty-acid Synthase, Suppresses the Mitochondrial Fatty Acid Synthesis Pathway and Impairs Mitochondrial Function

4-Methylene-2-octyl-5-oxotetrahydrofuran-3-carboxylic acid (C75) is a synthetic fatty-acid synthase (FASN) inhibitor with potential therapeutic effects in several cancer models. Human mitochondrial β-ketoacyl-acyl carrier protein synthase (HsmtKAS) is a key enzyme in the newly discovered mitochondrial fatty acid synthesis pathway that can produce the substrate for lipoic acid (LA) synthesis. HsmtKAS shares conserved catalytic domains with FASN, which are responsible for binding to C75. In our study, we explored the possible effect of C75 on HsmtKAS and mitochondrial function. C75 treatment decreased LA content, impaired mitochondrial function, increased reactive oxygen species content, and reduced cell viability. HsmtKAS but not FASN knockdown had an effect that was similar to C75 treatment. In addition, an LA supplement efficiently inhibited C75-induced mitochondrial dysfunction and oxidative stress. Overexpression of HsmtKAS showed cellular protection against low dose C75 addition, whereas there was no protective effect upon high dose C75 addition. In summary, the mitochondrial fatty acid synthesis pathway has a vital role in mitochondrial function. Besides FASN, C75 might also inhibit HsmtKAS, thereby reducing LA production, impairing mitochondrial function, and potentially having toxic effects. LA supplements sufficiently ameliorated the toxicity of C75, showing that a combination of C75 and LA may be a reliable cancer treatment.

Fatty Acid Synthase Inhibitor C75 Ameliorates Experimental Colitis

Abnormalities of lipid metabolism through overexpression of fatty acid synthase (FASN), which catalyzes the formation of long-chain fatty acids, are associated with the development of inflammatory bowel disease (IBD). C75 is a synthetic α-methylene-γ-butyrolactone compound that inhibits FASN activity. We hypothesized that C75 treatment could effectively reduce the severity of experimental colitis. Male C57BL/6 mice were fed 4% dextran sodium sulfate (DSS) for 7 d. C75 (5 mg/kg body weight) or dimethyl sulfoxide (DMSO) (vehicle) was administered intraperitoneally from d 2 to 6. Clinical parameters were monitored daily. Mice were euthanized on d 8 for histological evaluation and measurements of colon length, chemokine, cytokine and inflammatory mediator expression. C75 significantly reduced body weight loss from 23% to 15% on d 8, compared with the vehicle group. The fecal bleeding, diarrhea and colon histological damage scores in the C75-treated group were significantly lower than scores in the vehicle animals. Colon shortening was significantly improved after C75 treatment. C75 protected colon tissues from DSS-induced apoptosis by inhibiting caspase-3 activity. Macrophage inflammatory protein 2, keratinocyte-derived chemokine, myeloperoxidase activity and proinflammatory cytokines (tumor necrosis factor-α, interleukin [IL]-1β and IL-6) in the colon were significantly downregulated in the C75-treated group, compared with the vehicle group. Treatment with C75 in colitis mice inhibited the elevation of FASN, cyclooxygenase-2 and inducible nitric oxide synthase expression as well as IκB degradation in colon tissues. C75 administration alleviates the severity of colon damage and inhibits the activation of inflammatory pathways in DSS-induced colitis. Thus, inhibition of FASN may represent an attractive therapeutic potential for treating IBD.

Different fatty acid metabolism effects of (−)-Epigallocatechin-3-Gallate and C75 in Adenocarcinoma lung cancer

BackgroundFatty acid synthase (FASN) is overexpressed and hyperactivated in several human carcinomas, including lung cancer. We characterize and compare the anti-cancer effects of the FASN inhibitors C75 and (−)-epigallocatechin-3-gallate (EGCG) in a lung cancer model.MethodsWe evaluated in vitro the effects of C75 and EGCG on fatty acid metabolism (FASN and CPT enzymes), cellular proliferation, apoptosis and cell signaling (EGFR, ERK1/2, AKT and mTOR) in human A549 lung carcinoma cells. In vivo, we evaluated their anti-tumour activity and their effect on body weight in a mice model of human adenocarcinoma xenograft.ResultsC75 and EGCG had comparable effects in blocking FASN activity (96,9% and 89,3% of inhibition, respectively). In contrast, EGCG had either no significant effect in CPT activity, the rate-limiting enzyme of fatty acid β-oxidation, while C75 stimulated CPT up to 130%. Treating lung cancer cells with EGCG or C75 induced apoptosis and affected EGFR-signaling. While EGCG abolished p-EGFR, p-AKT, p-ERK1/2 and p-mTOR, C75 was less active in decreasing the levels of EGFR and p-AKT. In vivo, EGCG and C75 blocked the growth of lung cancer xenografts but C75 treatment, not EGCG, caused a marked animal weight loss.ConclusionsIn lung cancer, inhibition of FASN using EGCG can be achieved without parallel stimulation of fatty acid oxidation and this effect is related mainly to EGFR signaling pathway. EGCG reduce the growth of adenocarcinoma human lung cancer xenografts without inducing body weight loss. Taken together, EGCG may be a candidate for future pre-clinical development.

Stimulation of carnitine palmitoyltransferase 1 improves renal function and attenuates tissue damage after ischemia/reperfusion

BackgroundRenal injury as a result of ischemia/reperfusion (I/R) is a major clinical problem with a high mortality rate and a lack of therapeutic treatment. During I/R, cellular homeostasis is disrupted owing to energy depletion, leading to cell death. Fatty acid β-oxidation is the major metabolic pathway for generating adenosine triphosphate (ATP) in the kidneys, which is governed by carnitine palmitoyltransferase 1 (CPT1). C75 is a synthetic compound that up-regulates CPT1 activity. Thus, we hypothesized that C75 treatment could increase energy production and alleviate renal I/R injury. MethodsWe subjected male adult rats to renal I/R by bilateral renal pedicle clamping with microvascular clips for 60 min, followed by administration of 8% dimethyl sulfoxide (vehicle) or C75 (3 mg/kg body weight), with 5 animals/group. We collected blood and renal tissues 24 h after reperfusion and subjected them to various measurements and histological examination. ResultsC75 treatment restored the loss of CPT1 activity and intracellular ATP levels in the kidneys after I/R. Administration of C75 significantly lowered serum creatinine, blood urea nitrogen, aspartate aminotransferase, and lactate dehydrogenase levels elevated by I/R. C75 treatment preserved morphological features of the kidneys with a significant improvement in the damage score. In addition, C75 treatment inhibited the increase of TNF-α levels in serum and kidneys, and lowered myeloperoxidase activity in the kidneys after I/R. ConclusionsStimulation of CPT1 activity by C75 recovered ATP depletion, improved renal function, attenuated tissue injury, and inhibited proinflammatory cytokine production and neutrophil infiltration after renal I/R injury. Therefore, enhancing the metabolism pathways for energy production may provide a novel modality to treat renal I/R injury.

Diverse mechanisms of growth inhibition by luteolin, resveratrol, and quercetin in MIA PaCa-2 cells: a comparative glucose tracer study with the fatty acid synthase inhibitor C75

The rationale of this dose matching/dose escalating study was to compare a panel of flavonoids-luteolin, resveratrol, and quercetin-against the metabolite flux-controlling properties of a synthetic targeted fatty acid synthase inhibitor drug C75 on multiple macromolecule synthesis pathways in pancreatic tumor cells using [1,2-(13)C(2)]-d-glucose as the single precursor metabolic tracer. MIA PaCa-2 pancreatic adenocarcinoma cells were cultured for 48 h in the presence of 0.1% DMSO (control), or 50 or 100 μM of each test compound, while intracellular glycogen, RNA ribose, palmitate and cholesterol as well as extra cellular (13)CO(2), lactate and glutamate production patterns were measured using gas chromatography/mass spectrometry (GC/MS) and stable isotope-based dynamic metabolic profiling (SiDMAP). The use of 50% [1,2-(13)C(2)]-d-glucose as tracer resulted in an average of 24 excess (13)CO(2) molecules for each 1,000 CO(2) molecule in the culture media, which was decreased by 29 and 33% (P < 0.01) with 100 μM C75 and luteolin treatments, respectively. Extracellular tracer glucose-derived (13)C-labeled lactate fractions (Σm) were between 45.52 and 47.49% in all cultures with a molar ratio of 2.47% M + 1/Σm lactate produced indirectly by direct oxidation of glucose in the pentose cycle in control cultures; treatment with 100 μM C75 and luteolin decreased this figure to 1.80 and 1.67%. The tracer glucose-derived (13)C labeled fraction (Σm) of ribonucleotide ribose was 34.73% in controls, which was decreased to 20.58 and 8.45% with C75, 16.15 and 6.86% with luteolin, 27.66 and 19.25% with resveratrol, and 30.09 and 25.67% with quercetin, respectively. Luteolin effectively decreased nucleotide precursor synthesis pentose cycle flux primarily via the oxidative branch, where we observed a 41.74% flux (M + 1/Σm) in control cells, in comparison with only a 37.19%, 32.74%, or a 26.57%, 25.47% M + 1/Σm flux (P < 0.001) after 50 or 100 μM C75 or luteolin treatment. Intracellular de novo fatty acid palmitate (C16:0) synthesis was severely and equally blocked by C75 and luteolin treatments indicated by the 5.49% (control), 2.29 or 2.47% (C75) and 2.21 or 2.73% (luteolin) tracer glucose-derived (13)C-labeled fractions, respectively. On the other hand there was a significant 192 and 159% (P < 0.001), and a 103 and 117% (P < 0.01) increase in tracer glucose-derived cholesterol after C75 or luteolin treatment. Only resveratrol and quercetin at 100 μM inhibited tracer glucose-derived glycogen labeling (Σm) and turnover by 34.8 and 23.8%, respectively. The flavonoid luteolin possesses equal efficacy to inhibit fatty acid palmitate de novo synthesis as well as nucleotide RNA ribose turnover via the oxidative branch of the pentose cycle in comparison with the targeted fatty acid synthase inhibitor synthetic compound C75. Luteolin is also effective in stringently controlling glucose entry and anaplerosis in the TCA cycle, while it promotes less glucose flux towards cholesterol synthesis than that of C75. In contrast, quercetin and resveratrol inhibit glycogen synthesis and turnover as their underlying mechanism of controlling tumor cell proliferation. Therefore the flavonoid luteolin controls fatty and nucleic acid syntheses as well as energy production with pharmacological strength, which can be explored as a non-toxic natural treatment modality for pancreatic cancer.

C75 Alters Central and Peripheral Gene Expression to Reduce Food Intake and Increase Energy Expenditure

C75, a synthetic inhibitor of fatty acid synthase (FAS), causes anorexia and profound weight loss in lean and genetically obese mice. C75 also acts as a stimulator of carnitine palmitoyltransferase-1 to induce fatty acid oxidation. To approximate human obesity, we used a 2-wk C75 treatment model for diet-induced obese (DIO) mice to investigate the central and peripheral effects of C75 on gene expression. C75 treatment decreased food intake, increased energy expenditure, and reduced body weight more effectively in DIO than in lean mice. Analysis of the gene expression changes in hypothalamus demonstrated that the reduced food intake in C75-treated DIO mice might be mediated by inhibition of orexigenic neuropeptide expression and induction of anorexigenic neuropeptide expression. Gene expression changes in peripheral tissues indicated that C75 increased energy expenditure by the induction of genes involved in fatty acid oxidation. C75 also inhibited the expression of genes in peripheral tissues responsible for fatty acid synthesis and accumulation. The patterns of the changes in central and peripheral gene expression that occur with C75 treatment provide mechanisms to explain the reduced food intake and increased energy expenditure observed with C75.

Fatty acid synthase inhibitors are chemopreventive for mammary cancer in neu-N transgenic mice.

High levels of fatty acid synthase (FAS) have been found in cancer precursor lesions of the colon, stomach, esophagus, oral cavity, prostate, and breast. Inhibition of FAS with C75 has led to a significant antitumor effect in both human breast and prostate cancer xenografts. Recently, HER2/neu, which has also been identified in preneoplastic breast lesions, has been shown to regulate FAS expression through the PI3K/Akt signal transduction pathway rendering them susceptible to FAS inhibition. Utilizing the neu-N transgenic mouse model of mammary cancer, weekly treatment of the neu-N mice with C75 (30 mg/kg) for 10 weeks significantly delayed tumor progression. Only 20% of the C75-treated transgenic mice developed mammary carcinoma by 220 days, compared to 50% in the vehicle control animals. Two C75-treated animals never developed mammary cancer. Analysis of mammary tissue following 10 weeks of C75 treatment revealed a significant delay in mammary maturation as manifested by a reduction of the number and caliber of mammary ducts and budding epithelial structures. Apoptotic changes were increased, DNA synthesis was decreased, and the expressions of FAS, neu, Akt, phospho-Akt, and p21(waf1) were all decreased when compared to vehicle controls and FVB/N mice. Importantly, these effects were restricted to the breast epithelial cells that overexpressed neu, not involving other normal duct structures in the skin, liver, or kidney. C247, an FAS inhibitor chemically distinct from C75, significantly delayed mammary maturation similar to C75. Thus, pharmacological inhibition of FAS affects the expression of key oncogenes involved in both cancer development and maintenance of the malignant phenotype. Moreover, these data identify FAS as a potential novel drug target for breast cancer chemoprevention.

C75, a Fatty Acid Synthase Inhibitor, Reduces Food Intake via Hypothalamic AMP-activated Protein Kinase

Energy homeostasis and feeding are regulated by the central nervous system. C75, a fatty acid synthase (FAS) inhibitor, causes weight loss and anorexia, implying a novel central nervous system pathway(s) for sensing energy balance. AMP-activated protein kinase (AMPK), a sensor of peripheral energy balance, is phosphorylated and activated when energy sources are low. Here, we identify a role for hypothalamic AMPK in the regulation of feeding behavior and in mediating the anorexic effects of C75. 5-Aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR), an activator of AMPK, increased food intake, whereas compound C, an inhibitor of AMPK, decreased food intake. C75 rapidly reduced the level of the phosphorylated AMPK alpha subunit (pAMPKalpha) in the hypothalamus, even in fasted mice that had elevated hypothalamic pAMPKalpha levels. Furthermore, AICAR reversed both the C75-induced anorexia and the decrease in hypothalamic pAMPKalpha levels. C75 elevated hypothalamic neuronal ATP levels, which may contribute to the mechanism by which C75 decreased AMPK activity. C75 reduced the levels of pAMPKalpha and phosphorylated cAMP response element-binding protein (pCREB) in the arcuate nucleus neurons of the hypothalamus, suggesting a mechanism for the reduction in NPY expression seen with C75 treatment. These data indicate that modulation of FAS activity in the hypothalamus can alter energy perception via AMPK, which functions as a physiological energy sensor in the hypothalamus.