scholarly journals Combination of Mitochondrial and Plasma Membrane Citrate Transporter Inhibitors Inhibits De Novo Lipogenesis Pathway and Triggers Apoptosis in Hepatocellular Carcinoma Cells

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Wan-angkan Poolsri ◽  
Phornpun Phokrai ◽  
Somrudee Suwankulanan ◽  
Narinthorn Phakdeeto ◽  
Pattamaphorn Phunsomboon ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Plasma Membrane ◽  
Fatty Acid ◽  
Cancer Therapy ◽  
Cell Apoptosis ◽  
Hepg2 Cells ◽  
Cytotoxic Effect ◽  
De Novo ◽  
De Novo Lipogenesis ◽  
Citrate Transporter

Increased expression levels of both mitochondrial citrate transporter (CTP) and plasma membrane citrate transporter (PMCT) proteins have been found in various cancers. The transported citrates by these two transporter proteins provide acetyl-CoA precursors for the de novo lipogenesis (DNL) pathway to support a high rate of cancer cell viability and development. Inhibition of the DNL pathway promotes cancer cell apoptosis without apparent cytotoxic to normal cells, leading to the representation of selective and powerful targets for cancer therapy. The present study demonstrates that treatments with CTP inhibitor (CTPi), PMCT inhibitor (PMCTi), and the combination of CTPi and PMCTi resulted in decreased cell viability in two hepatocellular carcinoma cell lines (HepG2 and HuH-7). Treatment with citrate transporter inhibitors caused a greater cytotoxic effect in HepG2 cells than in HuH-7 cells. A lower concentration of combined CTPi and PMCTi promotes cytotoxic effect compared with either of a single compound. An increased cell apoptosis and an induced cell cycle arrest in both cell lines were reported after administration of the combined inhibitors. A combination treatment exhibits an enhanced apoptosis through decreased intracellular citrate levels, which consequently cause inhibition of fatty acid production in HepG2 cells. Apoptosis induction through the mitochondrial-dependent pathway was found as a consequence of suppressed carnitine palmitoyl transferase-1 (CPT-1) activity and enhanced ROS generation by combined CTPi and PMCTi treatment. We showed that accumulation of malonyl-CoA did not correlate with decreasing CPT-1 activity. The present study showed that elevated ROS levels served as an inhibition on Bcl-2 activity that is at least in part responsible for apoptosis. Moreover, inhibition of the citrate transporter is selectively cytotoxic to HepG2 cells but not in primary human hepatocytes, supporting citrate-mediating fatty acid synthesis as a promising cancer therapy.

scholarly journals Suppressed de novo lipogenesis by plasma membrane citrate transporter inhibitor promotes apoptosis in HepG2 cells

FEBS Open Bio ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 986-1000 ◽  
Author(s):  
Phornpun Phokrai ◽  
Wan‐angkan Poolsri ◽  
Somrudee Suwankulanan ◽  
Narinthorn Phakdeeto ◽  
Worasak Kaewkong ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Hepg2 Cells ◽  
De Novo ◽  
De Novo Lipogenesis ◽  
Citrate Transporter

EXTH-27. MOLECULAR CHARACTERIZATION AND PRECLINICAL DEVELOPMENT OF NOVEL SMALL MOLECULE INHIBITOR SPECIFIC FOR WILD-TYPE IDH1 FOR FERROPTOSIS INDUCTION IN GLIOBLASTOMA

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi169-vi169
Author(s):  
Kevin Murnan ◽  
Serena Tommasini-Ghelfi ◽  
Lisa Hurley ◽  
Corey Dussold ◽  
Daniel Wahl ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Cell Death ◽  
Plasma Membrane ◽  
Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
De Novo ◽  
De Novo Lipogenesis ◽  
Therapeutic Modality ◽  
Wild Type ◽  
Genetic Ablation

Abstract Increased de novo synthesis, mobilization and uptake of fatty acids are required to provide sufficient lipids for membrane biogenesis in support of rapid tumor cell division and growth. In addition to their structural roles as components of the plasma membrane, fatty acid-derived lipids regulate ferroptotic cell death, a type of programmed cell death, when oxidized by iron-dependent lipoxygenase enzymes. De novo lipogenesis and the defense against oxidative lipid damage require large amounts of cytosolic NADPH. Our group has recently found that HGG up-regulate wild-type Isocitrate dehydrogenase 1 (referred to hereafter as ‘wt-IDH1high HGG’) to generate large quantities of cytosolic NADPH. RNAi-mediated knockdown of wt-IDH1, alone and in combination with radiation therapy (RT), slows the growth of patient-derived HGG xenografts, while overexpression of wt-IDH1 promotes intracranial HGG growth. Isotope tracer and liquid chromatography-based lipidomic studies indicated that wt-IDH1 supports the de novo biosynthesis of mono-unsaturated fatty acids (MUFAs) and promotes the incorporation of monounsaturated phospholipids into the plasma membrane, while displacing polyunsaturated fatty acid (PUFA) phospholipids. In addition, enhanced NADPH production in wt-IDH1high HGG increases glutathione (GSH) level, reduces reactive oxygen species (ROS), activates the phospholipid peroxidase glutathione peroxidase 4 (GPX4)-driven lipid repair pathway, and dampens the accumulation of PUFA-containing lipid peroxides, known executioners of ferroptosis. To pharmacologically target wt-IDH1,we have used and characterized wt-IDH1i-13, a first-in-class competitive α,β-unsaturated enone (AbbVie). wt-IDH1i-13 potently inhibits wt-IDH1 enzymatic activity, by covalently binding to the NADP+ binding pocket. Our data indicate that wt-IDH1i-13 promotes ferroptosis, which can be rescued by pre-treatment of cells with the peroxyl scavenger and ferroptosis inhibitor ferrostatin. wt-IDH1i-13 is brain-penetrant, and similar to genetic ablation, reduces progression and extends the survival of wt-IDH1high HGG bearing mice, alone and in combination with RT. These studies credential to wt-IDH1i-13 as a novel therapeutic modality for the treatment of wt-IDH1 gliomas.

Raman spectroscopic imaging for investigations of de novo lipogenesis in hepatocellular carcinoma

2014 ◽  
Vol 52 (08) ◽  
Author(s):  
T Tolstik ◽  
C Marquardt ◽  
C Matthäus ◽  
C Beleites ◽  
C Krafft ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
De Novo ◽  
Spectroscopic Imaging ◽  
De Novo Lipogenesis ◽  
Raman Spectroscopic

SPARC regulates ferroptosis induced by sorafenib in human hepatocellular carcinoma

2021 ◽  
pp. 1-9
Author(s):  
Hong-Wei Hua ◽  
Hao-Sheng Jiang ◽  
Ling Jia ◽  
Yi-Ping Jia ◽  
Yu-Lan Yao ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Molecular Mechanism ◽  
Cancer Progression ◽  
Hepg2 Cells ◽  
Cytotoxic Effect ◽  
Cell Viability Assay ◽  
Viability Assay ◽  
Ldh Release ◽  
Related Proteins ◽  
Hcc Cells

BACKGROUND: Secreted protein acidic and rich in cysteine (SPARC) is implicated in cancer progression, but its role and associated molecular mechanism in the sorafenib sensitivity of hepatocellular carcinoma cells (HCC) remains elusive. METHODS: Human HCC cell lines Hep3B and HepG2 were treated with sorafenib alone or combined with activator or inhibitor of ferroptosis. Cell viability assay, reactive oxygen species (ROS) assay, lactate dehydrogenase (LDH) assay and western blot were used to study the regulatory mechanism of SPARC on HCC cells. RESULTS: Overexpression of SPARC enhanced the cytotoxic effect of sorafenib in Hep3B and HepG2 cells compared with parental cells. Depletion of SPARC decreased the cytotoxic effect of sorafenib in Hep3B and HepG2 cells compared with parental cells. Moreover, overexpression of SPARC significantly induced LDH release, whereas depletion of SPARC suppressed the release of LDH in Hep3B and HepG2 cells. Inhibition of ferroptosis exerted a clear inhibitory role against LDH release, whereas activation of ferroptosis promoted the release of LDH in HCC cells, as accompanied with deregulated expression of ferroptosis-related proteins. Furthermore, overexpression of SPARC induced oxidative stress, whereas depletion of SPARC suppressed the production of ROS. Deferoxamine (DFX)-induced inhibition of ferroptosis suppressed the production of ROS, while activation of ferroptosis promoted the contents of ROS in HCC cells exposed to sorafenib. CONCLUSION: Our findings give a better understanding of ferroptosis and its molecular mechanism in HCC cells that is regulated by SPARC in response to sorafenib.

Regulation of the SREBP transcription factors by mTORC1

2011 ◽  
Vol 39 (2) ◽  
pp. 495-499 ◽  
Author(s):  
Caroline A. Lewis ◽  
Beatrice Griffiths ◽  
Claudio R. Santos ◽  
Mario Pende ◽  
Almut Schulze
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Target Genes ◽  
De Novo ◽  
Regulatory Element ◽  
Cholesterol Biosynthesis ◽  
Mammalian Target Of Rapamycin ◽  
Lipid Biosynthesis ◽  
De Novo Lipogenesis ◽  
Genes Encoding

In recent years several reports have linked mTORC1 (mammalian target of rapamycin complex 1) to lipogenesis via the SREBPs (sterol-regulatory-element-binding proteins). SREBPs regulate the expression of genes encoding enzymes required for fatty acid and cholesterol biosynthesis. Lipid metabolism is perturbed in some diseases and SREBP target genes, such as FASN (fatty acid synthase), have been shown to be up-regulated in some cancers. We have previously shown that mTORC1 plays a role in SREBP activation and Akt/PKB (protein kinase B)-dependent de novo lipogenesis. Our findings suggest that mTORC1 plays a crucial role in the activation of SREBP and that the activation of lipid biosynthesis through the induction of SREBP could be part of a regulatory pathway that co-ordinates protein and lipid biosynthesis during cell growth. In the present paper, we discuss the increasing amount of data supporting the potential mechanisms of mTORC1-dependent activation of SREBP as well as the implications of this signalling pathway in cancer.

scholarly journals Targeting de novo lipogenesis and the Lands cycle induces ferroptosis in KRAS-mutant lung cancer

2021 ◽  
Author(s):  
Caterina Bartolacci ◽  
Cristina Andreani ◽  
Goncalo Dias do Vale ◽  
Stefano Berto ◽  
Margherita Melegari ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Fatty Acid ◽  
Metabolic Networks ◽  
Fatty Acid Synthase ◽  
De Novo ◽  
Genetically Engineered ◽  
De Novo Lipogenesis ◽  
Main Process

Mutant KRAS (KM) is the most common oncogene in lung cancer (LC). KM regulates several metabolic networks, but their role in tumorigenesis is still not sufficiently characterized to be exploited in cancer therapy. To identify metabolic networks specifically deregulated in KMLC, we characterized the lipidome of genetically engineered LC mice, cell lines, patient derived xenografts and primary human samples. We also determined that KMLC, but not EGFR-mutant (EGFR-MUT) LC, is enriched in triacylglycerides (TAG) and phosphatidylcholines (PC). We also found that KM upregulates fatty acid synthase (FASN), a rate-limiting enzyme in fatty acid (FA) synthesis promoting the synthesis of palmitate and PC. We determined that FASN is specifically required for the viability of KMLC, but not of LC harboring EGFR-MUT or wild type KRAS. Functional experiments revealed that FASN inhibition leads to ferroptosis, a reactive oxygen species (ROS)-and iron-dependent cell death. Consistently, lipidomic analysis demonstrated that FASN inhibition in KMLC leads to accumulation of PC with polyunsaturated FA (PUFA) chains, which are the substrate of ferroptosis. Integrating lipidomic, transcriptome and functional analyses, we demonstrated that FASN provides saturated (SFA) and monounsaturated FA (MUFA) that feed the Lands cycle, the main process remodeling oxidized phospholipids (PL), such as PC. Accordingly, either inhibition of FASN or suppression of the Lands cycle enzymes PLA2 and LPCAT3, promotes the intracellular accumulation of lipid peroxides and ferroptosis in KMLC both in vitro and in vivo. Our work supports a model whereby the high oxidative stress caused by KM dictates a dependency on newly synthesized FA to repair oxidated phospholipids, establishing a targetable vulnerability. These results connect KM oncogenic signaling, FASN induction and ferroptosis, indicating that FASN inhibitors already in clinical trial in KMLC patients (NCT03808558) may be rapidly deployed as therapy for KMLC.

scholarly journals Extraction, Structural Characterization, and Anti-Hepatocellular Carcinoma Activity of Polysaccharides From Panax ginseng Meyer

2021 ◽  
Vol 11 ◽  
Author(s):  
Hui Jia ◽  
Bin Zhao ◽  
Fangfang Zhang ◽  
Ramesh Kumar Santhanam ◽  
Xinying Wang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Hepg2 Cells ◽  
Cytotoxic Effect ◽  
Structural Characteristics ◽  
Gel Permeation Chromatography ◽  
Salting Out ◽  
Gel Permeation ◽  
Acidic Polysaccharides ◽  
Hepg2 Cell Lines ◽  
First Time

Polysaccharides are the main active ingredients of ginseng. To extract the most effective polysaccharides against hepatocellular carcinoma (HCC), we isolated and characterized the polysaccharides from the mountain cultivated ginseng (MCG) and compared their composition and cytotoxic effect with cultivated ginseng (CG) polysaccharide against HepG2 cell lines for the first time. MCG polysaccharides and CG polysaccharides were fractionated into two fractions such as MTPS-1, MTPS-2 and CTPS-1, CTPS-2 by salting out, respectively. Compared to CG, MCG possessed appreciable cytotoxic effect against HepG2 cells among that MTPS-1 possess fortified effect. Then, MTPS-1 was selected for further isolation process and seven acidic polysaccharides (MCGP-1–MCGP-7) were obtained using ethanol precipitation, ion-exchange, and gel permeation chromatography techniques. Structural characteristics of the polysaccharides (MCGP-1–MCGP-7) were done by adapting methylation/GC-MS and NMR analysis. Overall, MCGP-3 polysaccharide was found to possess significant cytotoxic effect against HepG2 cells with the IC50 value.

scholarly journals De novo lipogenesis is elicited dramatically in human hepatocellular carcinoma especially in hepatitis C virus‐induced hepatocellular carcinoma

MedComm ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 178-187
Author(s):  
Shaojian Li ◽  
Ruonan Liu ◽  
Qinling Pan ◽  
Genshu Wang ◽  
Daorou Cheng ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
De Novo ◽  
Human Hepatocellular Carcinoma ◽  
De Novo Lipogenesis

ZHX2 inhibits SREBP1c ‐mediated de novo lipogenesis in hepatocellular carcinoma via miR ‐24‐3p

2020 ◽  
Vol 252 (4) ◽  
pp. 358-370
Author(s):  
Xiangguo Yu ◽  
Qinghai Lin ◽  
Zhuanchang Wu ◽  
Yankun Zhang ◽  
Tixiao Wang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
De Novo ◽  
De Novo Lipogenesis

scholarly journals Therapeutic effect and autophagy regulation of myriocin in nonalcoholic steatohepatitis

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Rui-Xu Yang ◽  
Qin Pan ◽  
Xiao-Lin Liu ◽  
Da Zhou ◽  
Feng-Zhi Xin ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Liver Biopsy ◽  
High Fat Diet ◽  
Hepg2 Cells ◽  
De Novo ◽  
Sprague Dawley ◽  
Nonalcoholic Fatty Liver ◽  
Sprague Dawley Rats ◽  
Serum Transaminases ◽  
Lobular Inflammation

Abstract Background Ceramide plays pathogenic roles in nonalcoholic fatty liver disease (NAFLD) via multiple mechanisms, and as such inhibition of ceramide de novo synthesis in the liver may be of therapeutically beneficial in patients with NAFLD. In this study, we aimed to explore whether inhibition of ceramide signaling by myriocin is beneficial in animal model of NAFLD via regulating autophagy. Methods Sprague Dawley rats were randomly divided into three groups: standard chow (n = 10), high-fat diet (HFD) (n = 10) or HFD combined with oral administration of myriocin (0.3 mg/kg on alternate days for 8 weeks) (n = 10). Liver histology and autophagy function were measured. HepG2 cells were incubated with fatty acid with or without myriocin treatment. Lipid accumulation and autophagy markers in the HepG2 cells were analyzed. Serum ceramide changes were studied in 104 subjects consisting healthy adults, liver biopsy-proven patients with NAFLD and liver biopsy-proven patients with chronic hepatitis B (CHB). Results Myriocin reversed the elevated body weight and serum transaminases and alleviated dyslipidemia in HFD fed rats. Myriocin treatment significantly attenuated liver pathology including steatosis, lobular inflammation and ballooning. By qPCR analysis, it was revealed that myriocin corrected the expression pattern of fatty acid metabolism associated genes including Fabp1, Pparα, Cpt-1α and Acox-2. Further, myriocin also restored the impaired hepatic autophagy function in rats with HFD-induced NASH, and this has been verified in HepG2 cells. Among the sphingolipid species that we screened in lipidomic profiles, significantly increased ceramide was observed in NASH patients as compared to the controls and non-NASH patients, regardless of whether or not they have active CHB. Conclusions Ceramide may play an important regulatory role in the autophagy function in the pathogenesis of NASH. Hence, blockade of ceramide signaling by myriocin may be of therapeutically beneficial in NASH. Trial registration Registration ID: ChiCTR-DDT-13003983. Data of registration: 13 May, 2013, retrospectively registered.

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