Androgen receptor signaling as a new target for intervention in acute myeloid leukemia.

In addition to their role in development, sex hormones and their cognate receptors play an important role in various malignancies. Using a murine model of human MLL-AF9 induced acute myeloid leukemia (AML), we discovered that high Androgen receptor (AR) expressing leukemia initiating cells (LICs) when transferred into either male or female recipients resulted in more severe disease than low AR-expressing LICs. AR expression was significantly increased in female LICs compared to male LICs. This difference was confined to the LICs and not present in normal bone marrow cells. AML cells from both sexes relied on AR signaling via different mechanisms-females had high AR with low ligand, males, low AR with high ligand. AR expression was linked to EPHA7-associated PI3K/AKT/MTOR and SRC/HIF-1α pathways. Use of the two US FDA approved drugs for prostate cancer, ARN509, an AR antagonist and finasteride, which inhibits the pathway that produces dihydrotestosterone, resulted in significant remission with increased survival of AML mice. ARN509 and finasteride also showed pro-apoptotic effect in patient-derived AML cells and in a humanized AML model in NSG mice. These data support a drug repurpose effort to use anti-androgen therapy to improve the efficacy of AML treatments.