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Inhibition of de novo Palmitate Synthesis by Fatty Acid Synthase Induces Apoptosis in Tumor Cells by Remodeling Cell Membranes, Inhibiting Signaling Pathways, and Reprogramming Gene Expression.

Ventura R, Mordec K, Waszczuk J, Wang Z, Lai J, Fridlib M, Buckley D, Kemble G, Heuer TS - EBioMedicine (2015)

Bottom Line: Dose-dependent effects are observed between 20-200 nM TVB-3166, which agrees with the IC50 in biochemical FASN and cellular palmitate synthesis assays.Mechanistic studies show that FASN inhibition disrupts lipid raft architecture, inhibits biological pathways such as lipid biosynthesis, PI3K-AKT-mTOR and β-catenin signal transduction, and inhibits expression of oncogenic effectors such as c-Myc; effects that are tumor-cell specific.Our data demonstrate that selective and potent FASN inhibition with TVB-3166 leads to selective death of tumor cells, without significant effect on normal cells, and inhibits in vivo xenograft tumor growth at well-tolerated doses.

View Article: PubMed Central - PubMed

Affiliation: 3-V Biosciences, Menlo Park, CA, United States.

ABSTRACT

Unlabelled: Inhibition of de novo palmitate synthesis via fatty acid synthase (FASN) inhibition provides an unproven approach to cancer therapy with a strong biological rationale. FASN expression increases with tumor progression and associates with chemoresistance, tumor metastasis, and diminished patient survival in numerous tumor types. TVB-3166, an orally-available, reversible, potent, and selective FASN inhibitor induces apoptosis, inhibits anchorage-independent cell growth under lipid-rich conditions, and inhibits in-vivo xenograft tumor growth. Dose-dependent effects are observed between 20-200 nM TVB-3166, which agrees with the IC50 in biochemical FASN and cellular palmitate synthesis assays. Mechanistic studies show that FASN inhibition disrupts lipid raft architecture, inhibits biological pathways such as lipid biosynthesis, PI3K-AKT-mTOR and β-catenin signal transduction, and inhibits expression of oncogenic effectors such as c-Myc; effects that are tumor-cell specific. Our results demonstrate that FASN inhibition has anti-tumor activities in biologically diverse preclinical tumor models and provide mechanistic and pharmacologic evidence that FASN inhibition presents a promising therapeutic strategy for treating a variety of cancers, including those expressing mutant K-Ras, ErbB2, c-Met, and PTEN. The reported findings inform ongoing studies to link mechanisms of action with defined tumor types and advance the discovery of biomarkers supporting development of FASN inhibitors as cancer therapeutics.

Research in context: Fatty acid synthase (FASN) is a vital enzyme in tumor cell biology; the over-expression of FASN is associated with diminished patient prognosis and resistance to many cancer therapies. Our data demonstrate that selective and potent FASN inhibition with TVB-3166 leads to selective death of tumor cells, without significant effect on normal cells, and inhibits in vivo xenograft tumor growth at well-tolerated doses. Candidate biomarkers for selecting tumors highly sensitive to FASN inhibition are identified. These preclinical data provide mechanistic and pharmacologic evidence that FASN inhibition presents a promising therapeutic strategy for treating a variety of cancers.

No MeSH data available.


Related in: MedlinePlus

TVB-3166 modulates metabolic and growth-associated pathways in tumor cells. PANC-1 cells treated with TVB-3166 for 72 h were analyzed for gene expression changes using Affymetrix HU133 Plus 2.0 microarrays. Analysis includes unsupervised hierarchical clustering (A) and pathway enrichment analysis (B). Prostate and pancreatic tumor cell lines have similar changes: sterol biosynthesis pathway (top) and cell cycle pathway (bottom). 22Rv1 prostate tumor cells were treated with TVB-3166 for 48 h and gene expression changes were determined using RNA sequencing (RNASeq-25, Illumina, Inc). (C) Heat map showing 22Rv1 gene expression changes in lipid and sterol biosynthesis pathway genes. (D) RT-PCR validation of microarray and RNA sequencing data in PANC-1 and 22Rv1 cells and extension of results to CALU-6 and MRC5 cells.
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f0030: TVB-3166 modulates metabolic and growth-associated pathways in tumor cells. PANC-1 cells treated with TVB-3166 for 72 h were analyzed for gene expression changes using Affymetrix HU133 Plus 2.0 microarrays. Analysis includes unsupervised hierarchical clustering (A) and pathway enrichment analysis (B). Prostate and pancreatic tumor cell lines have similar changes: sterol biosynthesis pathway (top) and cell cycle pathway (bottom). 22Rv1 prostate tumor cells were treated with TVB-3166 for 48 h and gene expression changes were determined using RNA sequencing (RNASeq-25, Illumina, Inc). (C) Heat map showing 22Rv1 gene expression changes in lipid and sterol biosynthesis pathway genes. (D) RT-PCR validation of microarray and RNA sequencing data in PANC-1 and 22Rv1 cells and extension of results to CALU-6 and MRC5 cells.

Mentions: The significant changes that TVB-3166 exerts on membrane structure and signal transduction pathways, combined with the observation that tumor cells undergo apoptosis in response to drug treatment, caused us to evaluate of the impact of FASN inhibition on tumor cell gene expression. PANC-1 or 22Rv1 tumor cells growing in vitro were treated with 0.1 or 1 μM TVB-3166 and analyzed for changes in gene expression. Genome-wide analysis using microarray and RNA sequencing technology platforms showed extensive, coordinated, dose-dependent effects of FASN inhibition on the transcriptional activity of genes within pathways controlling tumor cell metabolism, proliferation, and survival. Genes with significant changes in mRNA abundance were identified using the statistical (p < 0.01) and fold change (> 1.6-fold) criteria (Fig. 5A; Supplemental Tables 1–2). Highly coordinated changes were evident in this analysis; the expression levels of multiple genes within a pathway were all coordinately increased or decreased. Pathway modulation by the induction of concerted gene expression changes is a remarkable feature of FASN inhibition. Examples of regulated pathways include up-regulation of sterol biosynthesis, pyruvate, amino acid, and glucose metabolism pathways and down-regulation of cell cycle, DNA replication, DNA-repair, and mitosis pathways (Table 2). Additional pathways with significantly increased gene expression include P53 signaling and apoptosis; whereas, the β-catenin, Notch, and the unfolded protein response pathways are down-regulated. Highly similar changes were found in both PANC-1 and 22Rv-1 cells (Fig. 5B). Many of the genes showing modulation in response to FASN inhibition are regulated downstream of the AKT–mTOR pathway via SREBP, e.g., genes within the sterol and lipid biosynthesis pathways (Fig. 5C), or the β-catenin pathway, e.g., genes involved in control of cell cycle progression and cell proliferation.


Inhibition of de novo Palmitate Synthesis by Fatty Acid Synthase Induces Apoptosis in Tumor Cells by Remodeling Cell Membranes, Inhibiting Signaling Pathways, and Reprogramming Gene Expression.

Ventura R, Mordec K, Waszczuk J, Wang Z, Lai J, Fridlib M, Buckley D, Kemble G, Heuer TS - EBioMedicine (2015)

TVB-3166 modulates metabolic and growth-associated pathways in tumor cells. PANC-1 cells treated with TVB-3166 for 72 h were analyzed for gene expression changes using Affymetrix HU133 Plus 2.0 microarrays. Analysis includes unsupervised hierarchical clustering (A) and pathway enrichment analysis (B). Prostate and pancreatic tumor cell lines have similar changes: sterol biosynthesis pathway (top) and cell cycle pathway (bottom). 22Rv1 prostate tumor cells were treated with TVB-3166 for 48 h and gene expression changes were determined using RNA sequencing (RNASeq-25, Illumina, Inc). (C) Heat map showing 22Rv1 gene expression changes in lipid and sterol biosynthesis pathway genes. (D) RT-PCR validation of microarray and RNA sequencing data in PANC-1 and 22Rv1 cells and extension of results to CALU-6 and MRC5 cells.
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Related In: Results  -  Collection

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f0030: TVB-3166 modulates metabolic and growth-associated pathways in tumor cells. PANC-1 cells treated with TVB-3166 for 72 h were analyzed for gene expression changes using Affymetrix HU133 Plus 2.0 microarrays. Analysis includes unsupervised hierarchical clustering (A) and pathway enrichment analysis (B). Prostate and pancreatic tumor cell lines have similar changes: sterol biosynthesis pathway (top) and cell cycle pathway (bottom). 22Rv1 prostate tumor cells were treated with TVB-3166 for 48 h and gene expression changes were determined using RNA sequencing (RNASeq-25, Illumina, Inc). (C) Heat map showing 22Rv1 gene expression changes in lipid and sterol biosynthesis pathway genes. (D) RT-PCR validation of microarray and RNA sequencing data in PANC-1 and 22Rv1 cells and extension of results to CALU-6 and MRC5 cells.
Mentions: The significant changes that TVB-3166 exerts on membrane structure and signal transduction pathways, combined with the observation that tumor cells undergo apoptosis in response to drug treatment, caused us to evaluate of the impact of FASN inhibition on tumor cell gene expression. PANC-1 or 22Rv1 tumor cells growing in vitro were treated with 0.1 or 1 μM TVB-3166 and analyzed for changes in gene expression. Genome-wide analysis using microarray and RNA sequencing technology platforms showed extensive, coordinated, dose-dependent effects of FASN inhibition on the transcriptional activity of genes within pathways controlling tumor cell metabolism, proliferation, and survival. Genes with significant changes in mRNA abundance were identified using the statistical (p < 0.01) and fold change (> 1.6-fold) criteria (Fig. 5A; Supplemental Tables 1–2). Highly coordinated changes were evident in this analysis; the expression levels of multiple genes within a pathway were all coordinately increased or decreased. Pathway modulation by the induction of concerted gene expression changes is a remarkable feature of FASN inhibition. Examples of regulated pathways include up-regulation of sterol biosynthesis, pyruvate, amino acid, and glucose metabolism pathways and down-regulation of cell cycle, DNA replication, DNA-repair, and mitosis pathways (Table 2). Additional pathways with significantly increased gene expression include P53 signaling and apoptosis; whereas, the β-catenin, Notch, and the unfolded protein response pathways are down-regulated. Highly similar changes were found in both PANC-1 and 22Rv-1 cells (Fig. 5B). Many of the genes showing modulation in response to FASN inhibition are regulated downstream of the AKT–mTOR pathway via SREBP, e.g., genes within the sterol and lipid biosynthesis pathways (Fig. 5C), or the β-catenin pathway, e.g., genes involved in control of cell cycle progression and cell proliferation.

Bottom Line: Dose-dependent effects are observed between 20-200 nM TVB-3166, which agrees with the IC50 in biochemical FASN and cellular palmitate synthesis assays.Mechanistic studies show that FASN inhibition disrupts lipid raft architecture, inhibits biological pathways such as lipid biosynthesis, PI3K-AKT-mTOR and β-catenin signal transduction, and inhibits expression of oncogenic effectors such as c-Myc; effects that are tumor-cell specific.Our data demonstrate that selective and potent FASN inhibition with TVB-3166 leads to selective death of tumor cells, without significant effect on normal cells, and inhibits in vivo xenograft tumor growth at well-tolerated doses.

View Article: PubMed Central - PubMed

Affiliation: 3-V Biosciences, Menlo Park, CA, United States.

ABSTRACT

Unlabelled: Inhibition of de novo palmitate synthesis via fatty acid synthase (FASN) inhibition provides an unproven approach to cancer therapy with a strong biological rationale. FASN expression increases with tumor progression and associates with chemoresistance, tumor metastasis, and diminished patient survival in numerous tumor types. TVB-3166, an orally-available, reversible, potent, and selective FASN inhibitor induces apoptosis, inhibits anchorage-independent cell growth under lipid-rich conditions, and inhibits in-vivo xenograft tumor growth. Dose-dependent effects are observed between 20-200 nM TVB-3166, which agrees with the IC50 in biochemical FASN and cellular palmitate synthesis assays. Mechanistic studies show that FASN inhibition disrupts lipid raft architecture, inhibits biological pathways such as lipid biosynthesis, PI3K-AKT-mTOR and β-catenin signal transduction, and inhibits expression of oncogenic effectors such as c-Myc; effects that are tumor-cell specific. Our results demonstrate that FASN inhibition has anti-tumor activities in biologically diverse preclinical tumor models and provide mechanistic and pharmacologic evidence that FASN inhibition presents a promising therapeutic strategy for treating a variety of cancers, including those expressing mutant K-Ras, ErbB2, c-Met, and PTEN. The reported findings inform ongoing studies to link mechanisms of action with defined tumor types and advance the discovery of biomarkers supporting development of FASN inhibitors as cancer therapeutics.

Research in context: Fatty acid synthase (FASN) is a vital enzyme in tumor cell biology; the over-expression of FASN is associated with diminished patient prognosis and resistance to many cancer therapies. Our data demonstrate that selective and potent FASN inhibition with TVB-3166 leads to selective death of tumor cells, without significant effect on normal cells, and inhibits in vivo xenograft tumor growth at well-tolerated doses. Candidate biomarkers for selecting tumors highly sensitive to FASN inhibition are identified. These preclinical data provide mechanistic and pharmacologic evidence that FASN inhibition presents a promising therapeutic strategy for treating a variety of cancers.

No MeSH data available.


Related in: MedlinePlus