Cancer cells are often dependent on epigenetic pathways for their survival. Consequently, drugs that target the epigenome, rather than the underlying DNA sequence, are currently attracting considerable attention. In recent years, the first epigenetic drugs have been approved for cancer chemotherapy, mainly for hematological applications. Limitations in single-drug efficacies have thus far limited their application in the treatment of solid tumors. Nevertheless, promising activity for these compounds has been suggested when combined with other, distinctly targeted agents. In this review, we discuss the anti-angiogenic activity of histone deacetylase and DNA methyltransferase inhibitors and their combinations with other targeted (anti-angiogenic) therapeutics in treatment of solid tumors. The role that these inhibitors play in the inhibition of tumor angiogenesis, particularly in combination with other targeted agents, and the advantages they present over broad acting anticancer agents, are critically discussed.
Keywords: Anti-angiogenesis; Clinical trials; Combination therapy; DNA methyltransferase inhibitors; Epi-drugs; Histone deacetylase inhibitors; Solid tumors; Tumor vasculature.