TCS HDAC6 20b

TCS HDAC6 20b is a potent and selective inhibitor of histone deacetylase 6 (HADC6) [1].

Histone deacetylases (HADC) are a series of enzymes that remove acetyl groups from an ε-N-acetyl lysine amino acid on a histone and make the histones to wrap the DNA more tightly, which prevent transcription. Mutation of HADC6 is associated with Alzheimer's disease.

In HCT116 cells, TCS HDAC6 20b increased ɑ-tubulin acetylation in a dose-dependent way without a significant increase in acetylated histone H4, which indicated that TCS HDAC6 20b selectively inhibit HDAC6 [1]. Treatment human colon cancer HCT116 cells with TCS HDAC6 20b (5 μM) and paclitaxel (PTX) (0.03 μM) inhibited cells growth by approximately 50%, which suggested that TCS HDAC6 20b has potential as drug candidates when used with PTX. In estrogen receptor ɑ (ERɑ) -positive breast cancer MCF-7 cells, treatment with 17β-estradiol (E2) (1 nM) increased cell growth by 40%, which was significantly blocked by TCS HDAC6 20b [2].

References:
[1].  Suzuki T, Kouketsu A, Itoh Y, et al. Highly potent and selective histone deacetylase 6 inhibitors designed based on a small-molecular substrate. J Med Chem, 2006, 49(16): 4809-4812.
[2].  Itoh Y, Suzuki T, Kouketsu A, et al. Design, synthesis, structure--selectivity relationship, and effect on human cancer cells of a novel series of histone deacetylase 6-selective inhibitors. J Med Chem, 2007, 50(22): 5425-5438.

[Inhibition effect of N-acetyl-seryl-aspartyl-lysyl-proline on myofibroblast differentiation by regulating acetylated tubulin alpha in silicotic rat model].[Pubmed:26887263]

Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi. 2015 Nov;33(11):816-21.

OBJECTIVE: To explore the inhibition effect and mechanism of N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP)on myofibroblast differentiation via regulating acetylated tubulin alpha (Ac-Tub alpha)in vivo and in vitro. METHODS: Silicotic model were made by SiO2 douched and divided into 6 groups as follows: control (4w, 8w)group, silicotic model (4w, 8w)group and post-or pre-treatment by Ac-SDKP group. Pulmonary fibroblasts were divided into 5 groups: (1) control; (2) Ang II; (3) Ang II+Ac-SDKP; (4) Ang II+Valsartan; (5) Ang II+TCS histone deacetylase (HDAC)6 20b. The localization of Ac-Tub alpha and alpha-smooth muscle actin (SMA) were observed by immunohistochemical (IHC) and immunofluorescence staining. The protein levels of Ac-Tub alpha, alpha-SMA, collagen type I (col I) and HDAC6 were measured by western blot. RESULTS: In silicotic nodules and interstitial fibrosis area, positive expression of alpha-SMA, a classical marker of myofibroblast, was ob-served by IHC, accompanied with absence expression of Ac-Tub alpha. Furthermore, Ac-SDKP post-treatment could attenuate the levels of col I, alpha-SMA and HDAC6 to 48.39%, 52.63% and 70.18% compared with the silicotic 8w group respectively. And in Ac-SDKP pre-treatment group, compared with the silicotic 8w group, these protein levels were decreased to 32.26%, 64.91% and 54.39% respectively (P<0.05). The up-regulation of Ac-Tub alpha was found in Ac-SDKP post-and pre-treatment and increased to 3.00 and 2.90 folds compared with the silicotic 8w group. Compared with control group, the levels of alpha-SMA, HDAC6 and col I in Ang II group were up-regulated to 1.66, 3.56 and 4.00 folds accompanied with down-regulation of Ac-Tub by 44.44% (P<0.05). Pre-treatment with Valsartan, TCS HDAC6 20b or Ac-SDKP could inhibited all this changes induced by Ang II in vitro. CONCLUSION: Ac-SDKP can inhibit the myofibroblast differentiation and collagen deposition via sup-press HDAC6 and up-regulate the expression of Ac-Tub alpha in vivo and in vitro.

Design, synthesis, structure--selectivity relationship, and effect on human cancer cells of a novel series of histone deacetylase 6-selective inhibitors.[Pubmed:17929798]

J Med Chem. 2007 Nov 1;50(22):5425-38.

To uncover novel histone deacetylase 6 (HDAC6)-selective inhibitors and to elucidate the structural requirements for their inhibitory activity, we designed and prepared a series of thiolate analogues based on the structure of an HDAC6-selective substrate and evaluated their properties by Western blotting and enzyme assays. Several thiolate analogues were found to be potent and selective HDAC6 inhibitors. Study of the structure-selectivity relationship revealed that the presence of a bulky alkyl group and tert-butylcarbamate group in these compounds is important for HDAC6-selective inhibition. Compounds 16b and 20b, the most selective and active compounds in this series, exerted a synergistic inhibition of cancer cell growth in combination with paclitaxel. They also blocked the growth of estrogen receptor alpha-positive breast cancer MCF-7 cells that had been treated with estrogen. These findings suggested that HDAC6-selective inhibitors have potential as anticancer agents.