HDAC1

HDAC1 is a class I histone deacetylase that supports transcriptional repression through histone deacetylase activity[1]. Mechanistically, HDAC1/2 form core catalytic components of corepressor complexes that modulate gene expression, linking chromatin regulation to proliferation and stem-cell self-renewal[2]. In human tumor cells, HDAC1 knockdown causes G1 or G2/M arrest, growth inhibition, loss of mitotic cells, and increased apoptosis[3]. In embryonic stem cells, HDAC1, but not HDAC2, is required for optimal corepressor-complex activity and cell-fate determination during differentiation[4]. Compared with HDAC2, HDAC1 shows nonredundant disease relevance in glioma stem cells, where its loss is not compensated by HDAC2 and affects the glioma stem-cell phenotype in a p53-dependent manner[5]. For experimental applications, selective HDAC1/2 inhibition suppresses colorectal cancer cells through apoptosis induction and cell-cycle regulation, supporting inhibitor use in pathway-focused cancer models[6].