HDAC

Notes

original target text: HDAC inhibitor

Histone deacetylases (HDACs) are a family of enzymes that remove acetyl groups from histone proteins, the structural spools around which DNA is wound, as well as from various non-histone proteins. Acetylation loosens the association between histones and DNA, opening chromatin and generally favoring gene transcription; deacetylation by HDACs tends to compact chromatin and silence gene expression. In many cancers, HDAC activity is dysregulated, leading to abnormal silencing of genes that would otherwise control cell division, promote differentiation, or trigger programmed cell death. Inhibiting HDACs allows acetyl groups to accumulate, reopening chromatin at these silenced loci and restoring more normal patterns of gene expression. This can slow proliferation, encourage cancer cells to differentiate toward a more mature state, or sensitize them to death signals. Beyond direct effects on chromatin, HDAC inhibition also affects non-histone proteins involved in cell signaling and protein stability, broadening its impact on tumor biology. Because HDACs exist as multiple subtypes distributed across different tissues, inhibitors can be designed as pan-inhibitors affecting most family members or as more selective agents. This mechanism is studied primarily in hematologic malignancies such as lymphomas, where epigenetic dysregulation is a prominent feature, though it has broader relevance across oncology.