Chromatin: a powerful new avenue of oncology research
Chromatin, a complex of proteins and DNA, is the format in which genetic information is stored within all living cells. In order for the cells to access this genetic information, and for transcription to take place, structural changes in chromatin have to occur. These changes are brought about by chromatin-modifying enzymes (CMEs) that add to, or remove, specific groups from the protein component (histones) of chromatin, forming a histone code. The histone code associated with individual genes is read by protein complexes that have the power to manipulate chromatin structure and hence make these genes available for transcription. The CMEs therefore play a crucial role in determining which genes are expressed and which are silenced. Cancer cells “hijack” these enzymes so that certain genes (tumour suppressor genes), which are used to protect the cell from the oncogenic transformation, are inappropriately switched off or genes that promote cancer (oncogenes) are inappropriately switched on.

This family of enzymes therefore represents a significant new approach to anti-cancer therapy in that the target family affects multiple aspects of tumour growth, is selective – it is only in cancer cells that inappropriate expression of these enzymes occurs – and the targets are “druggable” enzymes.