Romidepsin and azacitidine synergize in their epigenetic modulatory effects to induce apoptosis in CTCL

We demonstrate that the combination of the HDAC inhibitor, romidepsin, and the demethylating agent, azacitidine, exerts synergistic anti-proliferative effects and induction of apoptosis involving activation of the caspase cascade in CTCL cell lines as well as CD4+ T cells derived from patients with Sézary Syndrome (SS) with high tumor burden. We identified genes that were selectively induced by the combination treatment, such the tumor suppressor gene RhoB. We performed global CpG methylation-sequencing in a CTCL cell line and in patient cells. Results showed a subset of genes with a unique change in methylation profile in the combination treatment as compared to single drugs.