Activation of NOTCH signaling impedes cell proliferation and survival in acute megakaryoblastic leukemia.

The genetic lesions that drive acute megakaryoblastic leukemia (AMKL) have not been fully elucidated. To search for genetic alterations in AMKL, we performed targeted deep sequencing in 34 AMKL patient samples and 8 AMKL cell lines, and detected frequent genetic mutations in NOTCH pathway, besides previously reported alternations in GATA-1 and JAK-STAT pathway. Pharmacological and genetic NOTCH activation, but not inhibition, significantly suppressed AMKL cell proliferation in both in vitro and in vivo assays employing a patient derived xenograft model. These results suggest that NOTCH inactivation underlies AMKL leukemogenesis and NOTCH activation holds a potential of therapeutic application for AMKL.