TMP269

TMP269 is a novel and selective class IIa histone deacetylase (HDAC) inhibitor with IC50s of 157 nM, 97 nM, 43 nM and 23 nM for HDAC4, HDAC5, HDAC7 and HDAC9, respectively.

Research Areas >> Cancer

HDAC9:23 nM (IC50)

HDAC7:43 nM (IC50)

HDAC5:97 nM (IC50)

HDAC4:157 nM (IC50)

HDAC8:42000 nM (IC50)

HDAC6:82000 nM (IC50)

TMP269 has no impact on the mitochondrial activity and/or the viability of human CD4+ T cells at 10 μM, and may be used as tools to identify the endogenous substrates of the class IIa HDAC enzymes[1]. In IEC-18 intestinal epithelial cells, TMP269 prevents cell cycle progression, DNA synthesis, and proliferation induced in response to G protein-coupled receptor/PKD1 activation[2]. As with HDAC4 knockdown, TMP269 significantly enhances cytotoxicity induced by CFZ in MM cell lines, upregulating ATF4 and CHOP and inducing apoptosis. TMP269 does not hyperacetylate histone H3K9 or α-tubulin in MM cell lines, confirming that it has no inhibitory effects on class I or IIb HDACs. In a dosedependent manner, TPM269-induced cytotoxicity is associated with cleavage of caspase-8, -9, -3 and PARP, consistent with apoptosis[3].

Dose-response studies are done with ten concentrations in a threefold dilution series from a maximum final compound concentration of 100 μM in the reaction mixture. All assays are based on the same principle as the HDAC9 assay described above: the deacetylation of acetylated or trifluoroacetylated lysine residues on fluorogenic peptide substrates by HDAC. HDAC1, HDAC2, HDAC3, HDAC6, HDAC10 and HDAC11 used a substrate based on residues 379-382 of p53 (Arg-His-Lys-Lys(Ac)). For HDAC8, the diacetylated peptide substrate, based on residues 379-382 of p53 (Arg-His-Lys(Ac)-Lys(Ac)), is used. HDAC4, HDAC5, HDAC7 and HDAC9 assays used the class IIa HDAC-specific fluorogenic substrate (Boc-Lys(trifluoroacetyl)-AMC). All reactions are done with 50 μM HDAC substrate in assay buffer (50 mM Tris-HCl, pH 8.0, 137 mM NaCl, 2.7 mM KCl, 1 mM MgCl2, 1 mg/mL BSA) containing 1% DMSO final concentration; incubated for 2 h at 30°C; and developed with trichostatin A and trypsin.

Human CD4+ T cells are isolated from whole blood via negative selection according to manufacturer's instructions (RosetteSep Human CD4+ T cell enrichment kit), re-suspended in T-cell culture medium (10% FBS, 2 mM L-glutamine, 1 mM pyruvate, 10 mM HEPES, 10 U/10 mg penicillin/streptomycin, 0.5% DMSO in RPMI) and plated at 50,000 cells/well with IL-2 (10 BRMP units/mL) and 100,000 human T-expander Dynabeads for 72 h. Determination of mitochondrial function or cell viability is done according to manufacturer’s instructions (Cell Proliferation Assay Kit I (MTT)) and is represented as a percent of control (no inhibitor) wells.

[1]. Lobera M, et al. Selective class IIa histone deacetylase inhibition via a nonchelating zinc-binding group. Nat Chem Biol. 2013 May;9(5):319-25.

[2]. Sinnett-Smith J, et al. Protein kinase D1 mediates class IIa histone deacetylase phosphorylation and nuclear extrusion in intestinal epithelial cells: role in mitogenic signaling. Am J Physiol Cell Physiol. 2014 May 15;306(10):C961-71.

[3]. Kikuchi S, et al. Class IIa HDAC inhibition enhances ER stress-mediated cell death in multiple myeloma. Leukemia. 2015 Sep;29(9):1918-1927.

Trichostatin A | Entinostat (MS-275) | Romidepsin (FK228, Depsipeptide) | Mocetinostat(MGCD0103) | Ricolinostat (ACY-1215) | Sodium butyrate | RGFP 966 | Quisinostat | Tubacin | DL-Sulforaphane | CUDC-907 | LMK 235 | CI-994 | Tubastatin A | Sodium phenylbutyrate