Histone deacetylase 1, Histone deacetylase 2, and DNA (HDAC1/2-DNA)

The targeting of Histone Deacetylase 1 (HDAC1), Histone Deacetylase 2 (HDAC2), and DNA represents a multi-modal therapeutic strategy designed to overcome drug resistance in oncology (UniProt P19367, Q92769). HDAC1 and HDAC2 are Class I histone deacetylases that regulate gene expression by altering chromatin architecture; their overexpression is frequently associated with the silencing of pro-apoptotic and tumor suppressor genes. By inhibiting these enzymes, the chromatin is transitioned into an open, transcriptionally active state, which simultaneously increases the physical accessibility of the DNA to cytotoxic agents. Parallel targeting of DNA, typically through alkylation, exploits this increased accessibility to induce extensive DNA damage, such as interstrand cross-links and double-strand breaks (PMID: 28814451). This indirect synergy allows for potent induction of apoptosis even in cells with robust DNA repair mechanisms or those that are quiescent. Drugs like tinostamustine (EDO-S101) exemplify this approach by fusing an alkylating moiety with an HDAC inhibitor into a single molecule, ensuring simultaneous delivery to the nucleus (NCT02576405). This strategy is currently being investigated for the treatment of refractory hematologic malignancies and difficult-to-treat solid tumors like glioblastoma.

Other names

HDAC1/2 and DNA dual targetAlkylating histone deacetylase inhibitor targetHDAC-DNA parallel targetingAK-DAC target

Simultaneous inhibition of HDAC1 and HDAC2 enzymes alongside direct DNA alkylation; HDAC inhibition promotes an open chromatin structure, which enhances the accessibility of DNA to the alkylating moiety, leading to synergistic DNA damage and cell death.