Histone deacetylase Class I and II (HDAC Class I/II)

Class I and II Histone Deacetylases (HDACs) are a group of enzymes that play a pivotal role in epigenetic regulation by removing acetyl groups from lysine residues on histone tails and various non-histone proteins [5, 10, 13]. This deacetylation process leads to a more condensed chromatin structure, which typically results in the repression of gene transcription [8, 13]. HDACs are essential for regulating key cellular processes, including the cell cycle, apoptosis, DNA repair, and cellular differentiation [6, 14]. In many pathological states, particularly in various types of cancer, HDACs are frequently overexpressed or dysregulated, leading to the silencing of tumor suppressor genes and promoting malignant transformation [8, 13]. SB939, also known as Pracinostat, is a potent, orally bioavailable pan-HDAC inhibitor that targets Class I, II, and IV HDACs [1, 3]. By inhibiting these enzymes, SB939 induces the accumulation of acetylated histones and non-histone proteins, such as p53 and alpha-tubulin, which triggers chromatin remodeling and the reactivation of silenced genes [4, 7]. This molecular shift results in cell cycle arrest and the induction of apoptosis in cancer cells [2, 15]. Beyond oncology, Class I and II HDACs are also implicated in neurodegenerative and inflammatory diseases, making them significant therapeutic targets for a broad range of clinical applications [9, 11].

Other names

HDACsHistone deacetylasesLysine deacetylasesKDACs

Inhibition of histone deacetylase activity, leading to increased acetylation of histones and non-histone proteins, which results in chromatin remodeling, transcriptional activation of tumor suppressor genes, cell cycle arrest, and apoptosis [4, 13].