The implementation of targeted therapies for acute myeloid leukemia has been challenged by complex mutational patterns within and across patients as well as a dearth of pharmacologic agents for most mutational events. Here, we report initial findings from the Beat AML program on a cohort of 672 tumor specimens collected from 562 patients. We assessed these specimens using whole exome sequencing, RNA-sequencing, and ex vivo drug sensitivity analyses. Our data reveal Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:

BACKGROUND The molecular causes of many hematologic cancers remain unclear. Among these cancers are chronic neutrophilic leukemia (CNL) and atypical (BCR-ABL1–negative) chronic myeloid leukemia (CML), both of which are diagnosed on the basis of neoplastic expansion of granulocytic cells and exclusion of genetic drivers that are known to occur in other myeloproliferative neoplasms and myeloproliferative– myelodysplastic overlap neoplasms. METHODS To identify potential genetic drivers in these disorders, we used an integrated approach of deep sequencing coupled with the screening of primary leukemia cells obtained from patients with CNL or atypical CML against panels of tyrosine kinase–specific small interfering RNAs or small-molecule kinase inhibitors. We validated candidate oncogenes using in vitro transformation assays, and drug sensitivities were validated with the use of assays of primary-cell colonies. RESULTS We identified activating mutations in the gene encoding the receptor for colonystimulating factor 3 (CSF3R) in 16 of 27 patients (59%) with CNL or atypical CML. These mutations segregate within two distinct regions of CSF3R and lead to preferential downstream kinase signaling through SRC family–TNK2 or JAK kinases and differential sensitivity to kinase inhibitors. A patient with CNL carrying a JAK-activating CSF3R mutation had marked clinical improvement after the administration of the JAK1/2 inhibitor ruxolitinib. CONCLUSIONS Mutations in CSF3R are common in patients with CNL or atypical CML and represent a potentially useful criterion for diagnosing these neoplasms. (Funded by the Leukemia and Lymphoma Society and others.)

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Ca 2؉ ͞calmodulin-dependent protein kinase II (CaM-KII) regulates numerous physiological functions, including neuronal synaptic plasticity through the phosphorylation of ␣-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptors. To identify proteins that may interact with and modulate CaM-KII function, a yeast twohybrid screen was performed by using a rat brain cDNA library. This screen identified a unique clone of 1.4 kb, which encoded a 79-aa brain-specific protein that bound the catalytic domain of CaM-KII ␣ and ␤ and potently inhibited kinase activity with an IC 50 Ca2ϩ ͞calmodulin-dependent protein kinase II (CaM-KII) is a widely distributed protein kinase that is particularly abundant in neuronal tissues where it can constitute up to 1-2% of total protein (1). In vitro it can phosphorylate up to 40 proteins, including enzymes, ion channels, transcription factors, etc., and a number of these proteins appear to be physiological substrates. For example, CaM-KII is highly concentrated in the postsynaptic density of glutamatergic synapses where it phosphorylates and potentiates current through the ␣-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptor ion channel (AMPA-Rs) (2-4). This phosphorylation of AMPA-Rs occurs upon induction of long-term potentiation, a model of cellular learning and memory, in region CA1 of hippocampus and is thought to contribute to the postsynaptic current potentiation (2).Oligomeric CaM-KII is comprised of multiple subunits, each composed of an NH 2 -terminal catalytic domain, a central regulatory motif that includes autoinhibitory (AID) and overlapping CaM-binding elements, and a COOH-terminal region involved in subunit assembly (1, 5). The kinase is maintained in an inactive form because of interaction of the AID with the catalytic domain. Binding of Ca 2ϩ ͞CaM conformationally disrupts the AID, allowing access of the catalytic domain to substrates. CaM-KII has the unusual property that upon activation by Ca 2ϩ ͞CaM it exhibits rapid intersubunit autophoshorylation on Thr 286 , generating constitutive kinase activity (6, 7). This constitutive activity prolongs the kinase function beyond the transient elevations of intracellular Ca 2ϩ