miR-196b target screen reveals mechanisms maintaining leukemia stemness with therapeutic potential.

We have shown that antagomiR inhibition of miRNA miR-21 and miR-196b activity is sufficient to ablate MLL-AF9 leukemia stem cells (LSC) in vivo. Here, we used an shRNA screening approach to mimic miRNA activity on experimentally verified miR-196b targets to identify functionally important and therapeutically relevant pathways downstream of oncogenic miRNA in MLL-r AML. We found Cdkn1b (p27Kip1) is a direct miR-196b target whose repression enhanced an embryonic stem cell–like signature associated with decreased leukemia latency and increased numbers of leukemia stem cells in vivo. Conversely, elevation of p27Kip1 significantly reduced MLL-r leukemia self-renewal, promoted monocytic differentiation of leukemic blasts, and induced cell death. Antagonism of miR-196b activity or pharmacologic inhibition of the Cks1-Skp2–containing SCF E3-ubiquitin ligase complex increased p27Kip1 and inhibited human AML growth. This work illustrates that understanding oncogenic miRNA target pathways can identify actionable targets in leukemia

The anatomical distribution of genetic associations

Deeper understanding of the anatomical intermediaries for disease and other complex genetic traits is essential to understanding mechanisms and developing new interventions. Existing ontology tools provide functional, curated annotations for many genes and can be used to develop mechanistic hypotheses; yet information about the spatial expression of genes may be equally useful in interpreting results and forming novel hypotheses for a trait. Therefore, we developed an approach for statistically testing the relationship between gene expression across the body and sets of candidate genes from across the genome. We validated this tool and tested its utility on three applications. First, we show that the expression of genes in associated loci from GWA studies implicates specific tissues for 57 out of 98 traits. Second, we tested the ability of the tool to identify novel relationships between gene expression and phenotypes. Specifically, we experimentally confirmed an underappreciated prediction highlighted by our tool: that white blood cell count – a quantitative trait of the immune system – is genetically modulated by genes expressed in the skin. Finally, using gene lists derived from exome sequencing data, we show that human genes under selective constraint are disproportionately expressed in nervous system tissues

Synthesis, Structure and Thermal Properties of Volatile Indium and Gallium Triazenides

Indium and gallium nitride are important semi-conductor materials with desirable properties for high-frequency and power electronics. We have previously demonstrated high quality ALD grown InN and GaN using the hexacoordinated di-isopropyltriazenide In(III) and Ga(III) precursors. Herein we report the structural and thermal properties their analogues employing combinations of isopropyl, sec-butyl and tert-butyltriazenide alkyl groups on the exocyclic nitrogen of the triazenide ligand. The new triazenide compounds were all found to be volatile (80-120 ºC, 0.5 mbar) and showed very good thermal stability (200 and 300 °C). These new triazenide analogues provide a set of precursors whose thermal properties are determined and can be accordingly tailored by strategic choice of exocyclic nitrogen alkyl substituents

Synthesis of Substituted 4-(1H-indol-6-yl)-1H-indazoles as Potential PDK1 Inhibitors

The development of a preparative route to a series of novel 4-(1H-indol-6-yl)-1H-indazole compounds as potential PDK1 inhibitors is described. The synthetic strategy centres on the late-stage Suzuki crosscoupling of N-unprotected indazole and indole fragments. The use of a monoligated palladium catalyst system was found to be highly beneficial in the cross-coupling reaction. The indazole and indole fragments were constructed by diazotisation/cyclisation and SNAr/reductive cyclisation sequences, respectively

Deposition Study of Indium Trisguanidinate as a Possible Indium Nitride Precursor

A time-resolved chemical vapor deposition process for indium nitride (InN) is reported using tris-N,N-dimethyl-N’,N”-diisopropylguanidinatoindium(III) (1) and ammonia plasma at 200 °C. The deposition was self-limiting with respect to the pulse time of 1, indicative of a surface-controlled deposition chemistry. The films were confirmed to be InN by X-ray photoelectron spectroscopy (XPS) and film thicknesses of 10 nm were measured by X-ray reflectivity (XRR), corresponding to a deposition rate of 0.1 nm/cycle. Grazing incidence X-ray diffraction (GIXRD) showed a hexagonal polycrystalline film with a preferred (002) orientation. Morphology studies suggest an island growth mode. The poor thermal stability of 1, previously discussed in the literature, prevented full characterization of the deposition process and the deposition of thicker films. It is concluded that while 1 can act as an In precursor for InN, its poor thermal stability prevents its practical use. </p

Synthesis and Biological Evaluation of Substituted 2-anilino-7H-pyrrolopyrimidines as PDK1 Inhibitors

An efficient and scalable route for a series of novel substituted 2-anilino-7H-pyrrolopyrimidine compounds as potential inhibitors of PDK1, an important regulator of the PI3K/Akt pathway that is dysregulated in many cancers, was developed and is described. The synthetic strategy was designed around Suzuki and BuchwaldeHartwig cross-couplings of a boronate fragment and various customised anilines sequentially with 2,4-dichloro-7-tosyl-7H-pyrrolopyrimidine. All fragments were constructed separately and cross-coupled to provide access to a range of novel compounds. Biological evaluation of these was undertaken, with modest inhibition observed

Synthesis and Biological Evaluation of Substituted 3-anilino-quinolin-2(1H)-ones as PDK1 Inhibitors

PDK1 is an important regulator of the PI3K/Akt pathway, which has been found frequently activated in a large number of human cancers. Herein we described the preparation of novel substituted 3-anilino-quinolin-2(1H)-ones as PDK1 inhibitors. The synthesis is based around a Buchwald–Hartwig cross-coupling of various 3-bromo-6-substituted-quinolin-2(1H)-ones with three different functionalised anilines. The modular nature of the designed synthesis allowed access to a series of novel inhibitors through derivatisation of a late-stage intermediate. All compounds were screened against isolated PDK1 enzyme, with modest inhibition observed

The Endocyclic Carbon Substituent of Guanidinate and Amidinate Precursors Controlling ALD of InN Films

Indium nitride (InN) is an interesting material for future high frequency electronics, due to its high electron mobility. The problematic deposition of InN films currently prevents full exploration of InN based electronics. We present studies of atomic layer deposition (ALD) of InN using In precursors with bidentate ligands forming In–N bonds; tris(N,N-dimethyl-N’,N’’-diisoproprylguanidinato)indium(III), tris(N,N’-diisopropylamidinato)indium(III) and tris(N,N’-diisopropylformamidinato)indium(III). These compounds form a series were the size of the substituent in the endocyclic position decreases from –NMe2, to –Me and to –H, respectively. We show that when the size of the substituent decreases, InN films with higher crystalline- and optical quality, lower roughness and an In/N ratio closer to unity is achieved. From quantum chemical calculations we show that the smaller substituents lead to less steric repulsion and weaker bonds between the ligand and In centre. We propose that these effects render a more favoured surface chemistry for the nitidisation step in the ALD cycle which explains the improved film properties. </p