[CAS NO. 1252003-15-8]  Tubastatin A

Tubastatin A is selective at all isozymes except HDAC8 and maintains over 1000-fold selectivity against all isoforms excluding HDAC8, where it has approximately 57-fold selectivity. Tubastatin A preferentially induces α-tubulin hyperacetylation at 2.5 μM. Slight induction of histone hyperacetylation is seen for Tubastatin A at 10 μM. Tubastatin A displays dose-dependent protection against homocysteic acid-induced neuronal cell death starting at 5 μM with near complete protection at 10 μM. Tubastatin A (10 μM) induces an increase in acetylated-α-tubulin levels and the restoration of primary cilia expression in the cholangiocarcinoma cell lines (18-fold); and the restoration of primary cilia correlated with downregulated Hedgehog (Hh) and MAPK signaling pathways, as well as decreased cell proliferation rates (in average by 50%) and invasion (by 40%). Tubastatin A shows significant inhibition of TNF-α and IL-6 in LPS stimulated human THP-1 macrophages with an IC50 of 272 nM and 712 nM. Tubastatin A inhibits nitric oxide (NO) secretion in murine Raw 264.7 macrophages dose depenndently with an IC50 of 4.2 μM.