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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

FASN inhibition with TVB-3166 inhibits palmitate synthesis and tumor cell viability. (A) TVB-3166 chemical structure (left) and reversible dose response inhibition of palmitate synthesis in HeLa-Ohio cells (right). (B) Effects on cell viability in varied medium and serum conditions as shown. (C) TVB-3166 inhibits palmitate synthesis (gray) and viability (red) with the same dose response and IC50 values in CALU-6 tumor cells. In the presence of 25 μM exogenous palmitate (blue) tumor cell viability is not affected. MRC-5 fibroblasts (right) have the same palmitate synthesis IC50 value as CALU-6 tumor cells but without the effect on cell viability.
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f0010: FASN inhibition with TVB-3166 inhibits palmitate synthesis and tumor cell viability. (A) TVB-3166 chemical structure (left) and reversible dose response inhibition of palmitate synthesis in HeLa-Ohio cells (right). (B) Effects on cell viability in varied medium and serum conditions as shown. (C) TVB-3166 inhibits palmitate synthesis (gray) and viability (red) with the same dose response and IC50 values in CALU-6 tumor cells. In the presence of 25 μM exogenous palmitate (blue) tumor cell viability is not affected. MRC-5 fibroblasts (right) have the same palmitate synthesis IC50 value as CALU-6 tumor cells but without the effect on cell viability.

Mentions: In order to evaluate the anti-tumor properties of pharmacological FASN inhibition, we characterized the properties of TVB-3166 (Fig. 1A), which has a lower molecular weight and increased solubility than previously reported orally available, reversible, potent, and selective FASN inhibitors discovered and developed by 3-V Biosciences (Oslob et al., 2013). In particular, the physicochemical properties were optimized by replacing the benzimidazole moiety with a more polar pyrrazole group (Oslob et al., 2014). These changes improved both systemic and tumor exposures. TVB-3166 inhibits the keto-reductase enzymatic function of FASN. The activity and potency of this compound were demonstrated by growing HeLa cells in the presence of 13C-acetate for 18 h and observing dose dependent inhibition of 13C-labeled-palmitate synthesis measured by lipid extraction and mass spectrometry analysis (Fig. 1A). Very similar results were obtained using 13C-glucose in the place of 13C-acetate (data not shown). The cellular palmitate synthesis IC50 of 0.060 μM aligns with the in vitro FASN biochemical IC50 of 0.042 μM that measures the catalytic activity of purified FASN. FASN inhibition by TVB-3166 is reversible; this was demonstrated in a cell-based assay. HeLa cells were exposed to TVB-3166 for 4 h, followed by removal of the drug and addition of 13C-acetate for 18 h. Palmitate synthesis was not inhibited under these conditions compared to cells treated continuously with the inhibitor. These data demonstrated potent and reversible cellular FASN inhibition with TVB-3166.


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)

FASN inhibition with TVB-3166 inhibits palmitate synthesis and tumor cell viability. (A) TVB-3166 chemical structure (left) and reversible dose response inhibition of palmitate synthesis in HeLa-Ohio cells (right). (B) Effects on cell viability in varied medium and serum conditions as shown. (C) TVB-3166 inhibits palmitate synthesis (gray) and viability (red) with the same dose response and IC50 values in CALU-6 tumor cells. In the presence of 25 μM exogenous palmitate (blue) tumor cell viability is not affected. MRC-5 fibroblasts (right) have the same palmitate synthesis IC50 value as CALU-6 tumor cells but without the effect on cell viability.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

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f0010: FASN inhibition with TVB-3166 inhibits palmitate synthesis and tumor cell viability. (A) TVB-3166 chemical structure (left) and reversible dose response inhibition of palmitate synthesis in HeLa-Ohio cells (right). (B) Effects on cell viability in varied medium and serum conditions as shown. (C) TVB-3166 inhibits palmitate synthesis (gray) and viability (red) with the same dose response and IC50 values in CALU-6 tumor cells. In the presence of 25 μM exogenous palmitate (blue) tumor cell viability is not affected. MRC-5 fibroblasts (right) have the same palmitate synthesis IC50 value as CALU-6 tumor cells but without the effect on cell viability.
Mentions: In order to evaluate the anti-tumor properties of pharmacological FASN inhibition, we characterized the properties of TVB-3166 (Fig. 1A), which has a lower molecular weight and increased solubility than previously reported orally available, reversible, potent, and selective FASN inhibitors discovered and developed by 3-V Biosciences (Oslob et al., 2013). In particular, the physicochemical properties were optimized by replacing the benzimidazole moiety with a more polar pyrrazole group (Oslob et al., 2014). These changes improved both systemic and tumor exposures. TVB-3166 inhibits the keto-reductase enzymatic function of FASN. The activity and potency of this compound were demonstrated by growing HeLa cells in the presence of 13C-acetate for 18 h and observing dose dependent inhibition of 13C-labeled-palmitate synthesis measured by lipid extraction and mass spectrometry analysis (Fig. 1A). Very similar results were obtained using 13C-glucose in the place of 13C-acetate (data not shown). The cellular palmitate synthesis IC50 of 0.060 μM aligns with the in vitro FASN biochemical IC50 of 0.042 μM that measures the catalytic activity of purified FASN. FASN inhibition by TVB-3166 is reversible; this was demonstrated in a cell-based assay. HeLa cells were exposed to TVB-3166 for 4 h, followed by removal of the drug and addition of 13C-acetate for 18 h. Palmitate synthesis was not inhibited under these conditions compared to cells treated continuously with the inhibitor. These data demonstrated potent and reversible cellular FASN inhibition with TVB-3166.

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