SUMMARY Balanced chromosomal abnormalities (BCAs) represent a reservoir of single gene disruptions in neurodevelopmental disorders (NDD). We sequenced BCAs in autism and related NDDs, revealing disruption of 33 loci in four general categories: 1) genes associated with abnormal neurodevelopment (e.g., AUTS2, FOXP1, CDKL5), 2) single gene contributors to microdeletion syndromes (MBD5, SATB2, EHMT1, SNURF-SNRPN), 3) novel risk loci (e.g., CHD8, KIRREL3, ZNF507), and 4) genes associated with later onset psychiatric disorders (e.g., TCF4, ZNF804A, PDE10A, GRIN2B, ANK3). We also discovered profoundly increased burden of copy number variants among 19,556 neurodevelopmental cases compared to 13,991 controls (p = 2.07×10−47) and enrichment of polygenic risk alleles from autism and schizophrenia genome-wide association studies (p = 0.0018 and 0.0009, respectively). Our findings suggest a polygenic risk model of autism incorporating loci of strong effect and indicate that some neurodevelopmental genes are sensitive to perturbation by multiple mutational mechanisms, leading to variable phenotypic outcomes that manifest at different life stages.

Nucleophosmin 1 (NPM1) is an oligomeric, nucleolar phosphoprotein that functions as a molecular chaperone for both proteins and nucleic acids. NPM1 is mutated in approximately one-third of patients with AML. The mutant NPM1c؉ contains a 4-base insert that results in extra C-terminal residues encoding a nuclear export signal, which causes NPM1c؉ to be localized in the cytoplasm. Here, we determined the effects of targeting NPM1 in cultured and primary AML IntroductionNucleophosmin (NPM1 or B23.1) is a ubiquitously expressed, nucleolar phosphoprotein that functions as a molecular chaperone, shuttling between the nucleolus and the cytoplasm. 1-3 NPM1 plays multiple roles in cell growth and proliferation by participating in diverse biologic processes, including ribosome biogenesis and transport, centrosome duplication, DNA repair, transcriptional regulation and histone chaperoning. 4-7 Intracellular NPM1 is predominantly oligomeric and binds to other proteins, including the tumor suppressor proteins p14ARF and p53. 1,[8][9][10] Multifunctional characteristic of NPM1 appears to be dictated not only by its sub-cellular localization and its binding partners, but is also influenced by the various post translational modifications in NPM1, including acetylation, phosphorylation, poly-ubiquitination and sumoylation. [11][12][13][14] Wild-type (WT) NPM1 contains distinct structural domains that account for its ability to act as a multifunctional protein. 1,15 NPM1 has an N-terminal conserved, hydrophobic, oligomerization domain (residues, 1-110), which is common to all isoforms of NPM1 and critical for its chaperone activity. [1][2][3] Recently, NSC348884 was identified as a small molecule inhibitor that disrupts NPM1 dimer/oligomer formation, inducing apoptosis of cancer cells. 16 Oncogenic fusion proteins created by chromosomal translocation involving NPM1 gene, or mutations in NPM1 are observed in leukemia and lymphoma. 17 Notably, NPM-ALK fusion protein is found in CD30ϩ anaplastic large-cell lymphoma, 18 while leukemia related NPM1 fusion proteins include NPM-MLF1 and NPM-RAR␣. 17,19,20 These chimeric fusion proteins contain the N-terminal NPM1 oligomerization domain and a C-terminal fragment of the other protein. 17 NPM1 gene is also mutated in one third of adult acute myeloid leukemia (AML), especially those with the normal karyotype. 21 NPM1 mutations are heterozygous and, in the majority, localized to exon 12 of the gene. 21,22 Approximately 50 different types of mutations have been found, all creating the cytoplasm-dislocated mutant (Mt) NPM1 (NPM1cϩ) protein. 21,22 The most common is the type-A mutation, accounting for 75% of cases, which consists of TCTG tetranucleotide tandem duplication at position 956-959 of the NPM1 coding sequence. [22][23][24] This mutation causes the loss of tryptophans 288 and 290 (or 290 alone) from the carboxy-terminus and the creation of an additional leucine-rich nuclear export motif in the NPM1 protein, which causes the aberrant cytoplasmic dislocation of NPM1cϩ. [22][23][24] Knock...

Purpose We determined the activity of heat shock protein (hsp) 90 inhibitor (HI), and/or JAK2 tyrosine kinase inhibitor (TKI) against JAK2-V617F-expressing cultured mouse (Ba/F3-JAK2-V617F) and human (HEL92.1.7 and UKE1) or primary human CD34+ myeloproliferative neoplasm (MPN) cells. Experimental Design Following exposure to the HI AUY922 and/or JAK2-TKI TG101209, the levels of JAK2-V617F, its downstream signaling proteins, as well as apoptosis were determined. Results Treatment with AUY922 induced proteasomal degradation and depletion of JAK2-V617F as well as attenuated the signaling proteins downstream of JAK2-V617F, i.e., phospho (p)-STAT5, p-AKT and p-ERK1/2. AUY922 treatment also induced apoptosis of HEL92.1.7, UKE-1 and Ba/F3-hJAK2-V617F cells. Combined treatment with AUY922 and TG101209 caused greater depletion of the signaling proteins than either agent alone, and synergistically induced apoptosis of HEL92.1.7 and UKE-1 cells. Co-treatment with AUY922 and TG101209 also induced significantly more apoptosis of human CD34+ MPN versus normal hematopoietic progenitor cells. As compared to the sensitive controls, JAK2-TKI-resistant HEL/TGR and UKE1/TGR cells exhibited significantly higher IC50 values for JAK2-TKI (p <0.001), which was associated with higher expression of p-JAK2, p-STAT5, p-AKT and Bcl-xL, but reduced levels of BIM. Unlike the sensitive controls, HEL/TGR and UKE/TGR cells were collaterally sensitive to the HIs AUY922 and 17-AAG; accompanied by marked reduction in p-JAK2, p-STAT5, p-AKT and Bcl-xL, with concomitant induction of BIM. Conclusions Findings presented here demonstrate that co-treatment with HI and JAK2-TKI exerts synergistic activity against cultured and primary MPN cells. Additionally, treatment with HI may overcome resistance to JAK2-TKI in human MPN cells.

There is an unmet need to develop new, more effective and safe therapies for the aggressive forms of triple negative breast cancers (TNBCs). While up to 20% of women under 50 years of age with TNBC harbor germline mutations in BRCA1, and these tumors are sensitive to treatment with poly(ADP) ribose polymerase inhibitors, a majority of TNBCs lack BRCA1 mutations or loss of expression. Findings presented here demonstrate that by attenuating the levels of DNA damage response and homologous recombination proteins, pan-histone deacetylase inhibitor (HDI) treatment induces ‘BRCAness’ and sensitizes TNBC cells lacking BRCA1 to lethal effects of PARP inhibitor or cisplatin. Treatment with HDI also induced hyperacetylation of nuclear hsp90. Similar effects were observed following shRNA-mediated depletion of HDAC3, confirming its role as the deacetylase for nuclear HSP90. Furthermore, cotreatment with HDI and ABT-888 induced significantly more DNA strand breaks than either agent alone, and synergistically induced apoptosis of TNBC cells. Notably, co-treatment with HDI and ABT-888 significantly reduced in vivo tumor growth and markedly improved the survival of mice bearing TNBC cell xenografts. These findings support the rationale to interrogate the clinical activity of this novel combination against human TNBC, irrespective of its expression of mutant BRCA1.