Demethylation and re-expression of epigenetically silenced tumor suppressor genes: sensitization of cancer cells by combination therapy.

Epigenetic regulation in eukaryotic and mammalian systems is a complex and emerging field of study. While histone modifications create an open chromatin conformation allowing for gene transcription, CpG methylation adds a further dimension to the expression of specific genes in developmental pathways and carcinogenesis. In this review, we will highlight DNA methylation as one of the distinct mechanisms for gene silencing and try to provide insight into the role of epigenetics in cancer progenitor cell formation and carcinogenesis.

Anti-breast cancer effects of histone deacetylase inhibitors and calpain inhibitor.

Development of new breast cancer therapies is needed, particularly as cells become refractory or develop increased drug resistance. In an effort to develop such treatments, class I and II histone deacetylases (HDACs), alone and in combination with other cytotoxic agents, are currently in clinical trial. Herein, we discuss the effects of histone deacetylase inhibitors (HDACi) when used in combination with calpeptin, an inhibitor of the regulatory protease, calpain.