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Discovery, in vivo activity, and mechanism of action of a small-molecule p53 activator.

Lain S, Hollick JJ, Campbell J, Staples OD, Higgins M, Aoubala M, McCarthy A, Appleyard V, Murray KE, Baker L, Thompson A, Mathers J, Holland SJ, Stark MJ, Pass G, Woods J, Lane DP, Westwood NJ - Cancer Cell (2008)

Bottom Line: Here, we describe one of our hit compounds, tenovin-1, along with a more water-soluble analog, tenovin-6.Tenovins are active on mammalian cells at one-digit micromolar concentrations and decrease tumor growth in vivo as single agents.This underscores the utility of these compounds as biological tools for the study of sirtuin function as well as their potential therapeutic interest.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery and Molecular Oncology, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY Scotland, UK. s.lain@dundee.ac.uk

ABSTRACT
We have carried out a cell-based screen aimed at discovering small molecules that activate p53 and have the potential to decrease tumor growth. Here, we describe one of our hit compounds, tenovin-1, along with a more water-soluble analog, tenovin-6. Via a yeast genetic screen, biochemical assays, and target validation studies in mammalian cells, we show that tenovins act through inhibition of the protein-deacetylating activities of SirT1 and SirT2, two important members of the sirtuin family. Tenovins are active on mammalian cells at one-digit micromolar concentrations and decrease tumor growth in vivo as single agents. This underscores the utility of these compounds as biological tools for the study of sirtuin function as well as their potential therapeutic interest.

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Yeast Genetic Screen to Identify Tenovin-6 Hypersensitive Yeast Strains from within a Genome-wide Heterozygous Gene Deletion Collection(A) Plot of % control growth at 16.7 μM tenovin-6 versus growth in the absence of compound (OD600) for 6261 heterozygous gene deletion strains showing the positive correlation between growth in the presence of compound and overall growth in its absence. Outlier strains (511) showing potential hypersensitivity were identified as shown.(B) Examples of data from a secondary screen in which growth of a range of initial cell concentrations plus and minus compound were plotted. YDL010W is an example of a nonhypersensitive strain while YDL041W is the hypersensitive strain heterozygous for a SIR2 truncation. Graphs show the coefficient of linear correlation (R2) and best-fit equations giving the slope parameter used to generate the hypersensitivity index.(C) Histogram showing the distribution of hypersensitivity index values for 408 strains giving reproducible data and indicating the position of the YDL041W heterozygote (SIR2).
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fig4: Yeast Genetic Screen to Identify Tenovin-6 Hypersensitive Yeast Strains from within a Genome-wide Heterozygous Gene Deletion Collection(A) Plot of % control growth at 16.7 μM tenovin-6 versus growth in the absence of compound (OD600) for 6261 heterozygous gene deletion strains showing the positive correlation between growth in the presence of compound and overall growth in its absence. Outlier strains (511) showing potential hypersensitivity were identified as shown.(B) Examples of data from a secondary screen in which growth of a range of initial cell concentrations plus and minus compound were plotted. YDL010W is an example of a nonhypersensitive strain while YDL041W is the hypersensitive strain heterozygous for a SIR2 truncation. Graphs show the coefficient of linear correlation (R2) and best-fit equations giving the slope parameter used to generate the hypersensitivity index.(C) Histogram showing the distribution of hypersensitivity index values for 408 strains giving reproducible data and indicating the position of the YDL041W heterozygote (SIR2).

Mentions: Tenovin-6 inhibits the growth of S. cerevisiae cultures with an IC50 of 30 μM and is more toxic to yeast than the less water-soluble tenovin-1. We therefore screened 6,261 yeast strains for hypersensitivity to tenovin-6 and identified a strain heterozygous for a partial deletion of SIR2 among the most hypersensitive strains (Figure 4). This suggested that Sir2p homologs could be targets for tenovin-6 in mammalian cells. Two genes encoding proteins that directly or indirectly interact with Sir2p were also in the list of 16 hit candidate genes (see Discussion and Table S3).


Discovery, in vivo activity, and mechanism of action of a small-molecule p53 activator.

Lain S, Hollick JJ, Campbell J, Staples OD, Higgins M, Aoubala M, McCarthy A, Appleyard V, Murray KE, Baker L, Thompson A, Mathers J, Holland SJ, Stark MJ, Pass G, Woods J, Lane DP, Westwood NJ - Cancer Cell (2008)

Yeast Genetic Screen to Identify Tenovin-6 Hypersensitive Yeast Strains from within a Genome-wide Heterozygous Gene Deletion Collection(A) Plot of % control growth at 16.7 μM tenovin-6 versus growth in the absence of compound (OD600) for 6261 heterozygous gene deletion strains showing the positive correlation between growth in the presence of compound and overall growth in its absence. Outlier strains (511) showing potential hypersensitivity were identified as shown.(B) Examples of data from a secondary screen in which growth of a range of initial cell concentrations plus and minus compound were plotted. YDL010W is an example of a nonhypersensitive strain while YDL041W is the hypersensitive strain heterozygous for a SIR2 truncation. Graphs show the coefficient of linear correlation (R2) and best-fit equations giving the slope parameter used to generate the hypersensitivity index.(C) Histogram showing the distribution of hypersensitivity index values for 408 strains giving reproducible data and indicating the position of the YDL041W heterozygote (SIR2).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2742717&req=5

fig4: Yeast Genetic Screen to Identify Tenovin-6 Hypersensitive Yeast Strains from within a Genome-wide Heterozygous Gene Deletion Collection(A) Plot of % control growth at 16.7 μM tenovin-6 versus growth in the absence of compound (OD600) for 6261 heterozygous gene deletion strains showing the positive correlation between growth in the presence of compound and overall growth in its absence. Outlier strains (511) showing potential hypersensitivity were identified as shown.(B) Examples of data from a secondary screen in which growth of a range of initial cell concentrations plus and minus compound were plotted. YDL010W is an example of a nonhypersensitive strain while YDL041W is the hypersensitive strain heterozygous for a SIR2 truncation. Graphs show the coefficient of linear correlation (R2) and best-fit equations giving the slope parameter used to generate the hypersensitivity index.(C) Histogram showing the distribution of hypersensitivity index values for 408 strains giving reproducible data and indicating the position of the YDL041W heterozygote (SIR2).
Mentions: Tenovin-6 inhibits the growth of S. cerevisiae cultures with an IC50 of 30 μM and is more toxic to yeast than the less water-soluble tenovin-1. We therefore screened 6,261 yeast strains for hypersensitivity to tenovin-6 and identified a strain heterozygous for a partial deletion of SIR2 among the most hypersensitive strains (Figure 4). This suggested that Sir2p homologs could be targets for tenovin-6 in mammalian cells. Two genes encoding proteins that directly or indirectly interact with Sir2p were also in the list of 16 hit candidate genes (see Discussion and Table S3).

Bottom Line: Here, we describe one of our hit compounds, tenovin-1, along with a more water-soluble analog, tenovin-6.Tenovins are active on mammalian cells at one-digit micromolar concentrations and decrease tumor growth in vivo as single agents.This underscores the utility of these compounds as biological tools for the study of sirtuin function as well as their potential therapeutic interest.

View Article: PubMed Central - PubMed

Affiliation: Department of Surgery and Molecular Oncology, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY Scotland, UK. s.lain@dundee.ac.uk

ABSTRACT
We have carried out a cell-based screen aimed at discovering small molecules that activate p53 and have the potential to decrease tumor growth. Here, we describe one of our hit compounds, tenovin-1, along with a more water-soluble analog, tenovin-6. Via a yeast genetic screen, biochemical assays, and target validation studies in mammalian cells, we show that tenovins act through inhibition of the protein-deacetylating activities of SirT1 and SirT2, two important members of the sirtuin family. Tenovins are active on mammalian cells at one-digit micromolar concentrations and decrease tumor growth in vivo as single agents. This underscores the utility of these compounds as biological tools for the study of sirtuin function as well as their potential therapeutic interest.

Show MeSH
Related in: MedlinePlus