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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 inhibits and anchorage-independent growth in soft agar induces apoptosis. (A) Soft agar colony growth assays. Cells were treated with TVB-3166 for 21–28 days in IMDM plus 10% FBS. Cells were plated in 0.35% ultrapure agarose over a solidified base layer of 0.6% bacteriological agar. (B) TVB-3166 induces apoptosis in CALU-6 (lung) and 22Rv1 (prostate) tumor cells. Cells were treated with TVB-3166 for 72 (22Rv1 cells) or 96 h (CALU-6 cells) in Advanced MEM media with 1% CF FBS. Annexin V and propidium iodide staining were measured by flow cytometry. Cleaved PAPR was detected by Western blot analysis.
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f0020: FASN inhibition inhibits and anchorage-independent growth in soft agar induces apoptosis. (A) Soft agar colony growth assays. Cells were treated with TVB-3166 for 21–28 days in IMDM plus 10% FBS. Cells were plated in 0.35% ultrapure agarose over a solidified base layer of 0.6% bacteriological agar. (B) TVB-3166 induces apoptosis in CALU-6 (lung) and 22Rv1 (prostate) tumor cells. Cells were treated with TVB-3166 for 72 (22Rv1 cells) or 96 h (CALU-6 cells) in Advanced MEM media with 1% CF FBS. Annexin V and propidium iodide staining were measured by flow cytometry. Cleaved PAPR was detected by Western blot analysis.

Mentions: To characterize the effects of FASN inhibition on tumor cell growth and survival further, studies were performed to assess the effect of FASN inhibition on soft agar colony growth under conditions of complete media with 10% FBS. Several tumor cell lines, representing lung, ovary, prostate, and colorectal tumors, were examined at 0.1 or 1.0 μM TVB-3166. In each of the different tumor cells, dose dependent inhibition of colony growth was observed. At a lower dose of 0.1 μM TVB-3166 the most prominent effect is reduced colony size; however, at a concentration of 1.0 μM both colony size and number were inhibited. Colony growth of COLO-205, CALU-6, and OVCAR-8 cells showed heightened sensitivity to FASN inhibition compared to 22Rv1 cells (Fig. 3A). Together the ATP and soft agar assay results demonstrate that FASN inhibition interferes with cell growth, proliferation, and viability under varying medium and serum conditions that include 1–10% FBS.


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 inhibits and anchorage-independent growth in soft agar induces apoptosis. (A) Soft agar colony growth assays. Cells were treated with TVB-3166 for 21–28 days in IMDM plus 10% FBS. Cells were plated in 0.35% ultrapure agarose over a solidified base layer of 0.6% bacteriological agar. (B) TVB-3166 induces apoptosis in CALU-6 (lung) and 22Rv1 (prostate) tumor cells. Cells were treated with TVB-3166 for 72 (22Rv1 cells) or 96 h (CALU-6 cells) in Advanced MEM media with 1% CF FBS. Annexin V and propidium iodide staining were measured by flow cytometry. Cleaved PAPR was detected by Western blot analysis.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

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f0020: FASN inhibition inhibits and anchorage-independent growth in soft agar induces apoptosis. (A) Soft agar colony growth assays. Cells were treated with TVB-3166 for 21–28 days in IMDM plus 10% FBS. Cells were plated in 0.35% ultrapure agarose over a solidified base layer of 0.6% bacteriological agar. (B) TVB-3166 induces apoptosis in CALU-6 (lung) and 22Rv1 (prostate) tumor cells. Cells were treated with TVB-3166 for 72 (22Rv1 cells) or 96 h (CALU-6 cells) in Advanced MEM media with 1% CF FBS. Annexin V and propidium iodide staining were measured by flow cytometry. Cleaved PAPR was detected by Western blot analysis.
Mentions: To characterize the effects of FASN inhibition on tumor cell growth and survival further, studies were performed to assess the effect of FASN inhibition on soft agar colony growth under conditions of complete media with 10% FBS. Several tumor cell lines, representing lung, ovary, prostate, and colorectal tumors, were examined at 0.1 or 1.0 μM TVB-3166. In each of the different tumor cells, dose dependent inhibition of colony growth was observed. At a lower dose of 0.1 μM TVB-3166 the most prominent effect is reduced colony size; however, at a concentration of 1.0 μM both colony size and number were inhibited. Colony growth of COLO-205, CALU-6, and OVCAR-8 cells showed heightened sensitivity to FASN inhibition compared to 22Rv1 cells (Fig. 3A). Together the ATP and soft agar assay results demonstrate that FASN inhibition interferes with cell growth, proliferation, and viability under varying medium and serum conditions that include 1–10% FBS.

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