R. Singh, Kyongshin Cho, Satish K R Padi
Jan 20, 2015
Citations
2
Influential Citations
21
Citations
Quality indicators
Journal
The Journal of Biological Chemistry
Abstract
Background: N-Acylthiourea (TM-2-51) is an HDAC8-selective activator. Results: TM-2-51 binds to HDAC8 at two sites in a positive cooperative manner, and it produces anticancer effect in neuroblastoma cells. Conclusion: TM-2-51 modulates the binding thermodynamics/kinetics of substrate/inhibitor to HDAC8, and it enhances the cellular expression of p53/p21. Significance: These mechanistic studies will shed light on designing HDAC-selective activators as potential therapeutic agents. We reported previously that an N-acylthiourea derivative (TM-2-51) serves as a potent and isozyme-selective activator for human histone deacetylase 8 (HDAC8). To probe the molecular mechanism of the enzyme activation, we performed a detailed account of the steady-state kinetics, thermodynamics, molecular modeling, and cell biology studies. The steady-state kinetic data revealed that TM-2-51 binds to HDAC8 at two sites in a positive cooperative manner. Isothermal titration calorimetric and molecular modeling data conformed to the two-site binding model of the enzyme-activator complex. We evaluated the efficacy of TM-2-51 on SH-SY5Y and BE(2)-C neuroblastoma cells, wherein the HDAC8 expression has been correlated with cellular malignancy. Whereas TM-2-51 selectively induced cell growth inhibition and apoptosis in SH-SY5Y cells, it showed no such effects in BE(2)-C cells, and this discriminatory feature appears to be encoded in the p53 genotype of the above cells. Our mechanistic and cellular studies on HDAC8 activation have the potential to provide insight into the development of novel anticancer drugs.