Therapeutic targeting potential of chromatin-associated proteins in MLL-rearranged acute leukemia.

BACKGROUND: Acute leukemias (AL) with a Mixed Lineage Leukemia (MLL) gene rearrangement (MLLr) represent a group of leukemic entities conferring intermediate to adverse prognoses. Multiple chromatin-associated proteins have been shown to play essential roles during the genesis of MLLr AL. Some chromatin-associated proteins function as negative regulators of MLLr AL whereas others are required for leukemic initiation or maintenance - the latter group constituting potential therapeutic targets. Most of the identified proteins have been functionally analyzed using experimental models with human/murine normal cells transformed by MLL-AF9 or other MLL fusion products, which may recapitulate most but not all aspects of human AML, such as immune system interactions - features of which the importance is rapidly emerging.

CONCLUSIONS: Here, we review chromatin-associated proteins fundamental to MLLr AL development, highlighting those with targeting potential by small molecule inhibitors. In particular, we focus on synthetic targeting of multiple chromatin-associated proteins, a strategy that shows superior therapeutic efficacy and offers hope for overcoming drug resistance.