PD 334581

Co-expression of AFAP1-AS1 and PD-1 predicts poor prognosis in nasopharyngeal carcinoma.[Pubmed:28380458]

Oncotarget. 2017 Jun 13;8(24):39001-39011.

Nasopharyngeal carcinoma (NPC) carries a high potential for metastasis and immune escape, with a great risk of relapse after primary treatment. Through analysis of whole genome expression profiling data in NPC samples, we found that the expression of a long non-coding RNA (lncRNA), actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1), is significantly correlated with the immune escape marker programmed death 1 (PD-1). We therefore assessed the expression of AFAP1-AS1 and PD-1 in a cohort of 96 paraffin-embedded NPC samples and confirmed that AFAP1-AS1 and PD-1 are co-expressed in infiltrating lymphocytes in NPC tissue. Moreover, patients with high expression of AFAP1-AS1 or PD-1 in infiltrating lymphocytes were more prone to distant metastasis, and NPC patients with positive expression of both AFAP1-AS1 and PD-1 had the poorest prognosis. This study suggests that AFAP1-AS1 and PD-1 may be potential therapeutic targets in NPC and that patients with co-expression of AFAP1-AS1 and PD-1 may be ideal candidates for future clinical trials of anti-PD-1 immune therapy.

Mechanistic insight into the regioselectivity of Pd(ii)-catalyzed C-H functionalization of N-methoxy cinnamamide.[Pubmed:28379232]

Dalton Trans. 2017 Apr 19;46(16):5288-5296.

Computational studies have been applied to gain insight into the mechanism of Pd(ii) catalyzed alpha-C-H functionalization of N-methoxy cinnamamide. The results show that the whole catalytic cycle proceeds via sequential six steps, including (i) catalyst Pd(t-BuNC)2 oxidation with O2, (ii) O-H deprotonation, (iii) t-BuNC migratory insertion to the Pd-C bond, (iv) acyl migration, (v) C-H activation and (vi) reductive elimination. The regioselectivity for different C-H activation sites depends on the coordination structures of alpha-C or beta-C to the palladium(ii) center. The coordination of alpha-C to the palladium(ii) center shows a regular planar quadrilateral structure, which is stable. However, the beta-C coordinating to the palladium(ii) center mainly exhibits a distorted quadrilateral structure, which is relatively unstable. Thus, the barrier of alpha-C-H activation is much lower than that of beta-C-H activation. The present results provide a deep understanding of the site-selectivity of C-H activation.

Three 1D cyanide-bridged M(Ni, Pd, Pt)-Mn(II) Coordination Polymer: Synthesis, Crystal Structure and Magnetic Properties.[Pubmed:28380238]

Acta Chim Slov. 2017 Mac;64(1):215-220.

Three tetracyanide-containing building blocks K2[M(CN)4] (M = Ni, Pd, Pt) and one semi-closed macrocycle seven-coordinated manganese(II) compound have been employed to assemble cyanide-bridged heterometallic complexes, resulting in three cyanide-bridged MII-MnII complexes: [Mn(L)][Ni(CN)4] . 2H2O (1) [Mn(L)][Pd(CN)4] (2) and [Mn(L)][Pt(CN)4] (3) (L = 2,6-bis[1-(2-(N-methylamino)ethylimino)ethyl]pyridine). Single-crystal X-ray diffraction analysis shows their similar one-dimensional structure consisting of the alternating [Mn(L)]2+ species and [M(CN)4]2- building blocks, generating a cyanide-bridged neutral polymeric chain. In all three isostructural complexes the coordination geometry of manganese ion is a slightly distorted pentagonal-bipyramidal with the two cyanide nitrogen atoms at the trans positions and N5 coordinating mode at the equatorial plane from ligand L. Investigation over magnetic properties of these complexes reveals very weak antiferromagnetic interaction between neighboring Mn(II) ions bridged by the long NC-M-CN unit. A best-fit to the magnetic susceptibility of complexes 1-3 leads to the magnetic coupling constant of J = -0.081, -0.103 and -0.14 cm-1, respectively.

Pd-Catalyzed Autotandem Reactions with N-Tosylhydrazones. Synthesis of Condensed Carbo- and Heterocycles by Formation of a C-C Single Bond and a C horizontal lineC Double Bond on the Same Carbon Atom.[Pubmed:28379703]

Org Lett. 2017 Apr 21;19(8):2034-2037.

A new Pd-catalyzed autotandem reaction is introduced that consists of the cross-coupling of a benzyl bromide with a N-tosylhydrazone followed by an intramolecular Heck reaction with an aryl bromide. During the process, a single and a double C-C bond are formed on the same carbon atom. Two different arrangements for the reactive functional groups are possible, rendering great flexibility to the transformation. The same strategy led to 9-methylene-9H-fluorenes, 9-methylene-9H-xanthenes, 9-methylene-9,10-dihydroacridines, and also dihydropyrroloisoquinoline and dihydroindoloisoquinoline derivatives.

Targeting cancer with small molecule kinase inhibitors.[Pubmed:19104514]

Nat Rev Cancer. 2009 Jan;9(1):28-39.

Deregulation of kinase activity has emerged as a major mechanism by which cancer cells evade normal physiological constraints on growth and survival. To date, 11 kinase inhibitors have received US Food and Drug Administration approval as cancer treatments, and there are considerable efforts to develop selective small molecule inhibitors for a host of other kinases that are implicated in cancer and other diseases. Herein we discuss the current challenges in the field, such as designing selective inhibitors and developing strategies to overcome resistance mutations. This Review provides a broad overview of some of the approaches currently used to discover and characterize new kinase inhibitors.

Structures of human MAP kinase kinase 1 (MEK1) and MEK2 describe novel noncompetitive kinase inhibition.[Pubmed:15543157]

Nat Struct Mol Biol. 2004 Dec;11(12):1192-7.

MEK1 and MEK2 are closely related, dual-specificity tyrosine/threonine protein kinases found in the Ras/Raf/MEK/ERK mitogen-activated protein kinase (MAPK) signaling pathway. Approximately 30% of all human cancers have a constitutively activated MAPK pathway, and constitutive activation of MEK1 results in cellular transformation. Here we present the X-ray structures of human MEK1 and MEK2, each determined as a ternary complex with MgATP and an inhibitor to a resolution of 2.4 A and 3.2 A, respectively. The structures reveal that MEK1 and MEK2 each have a unique inhibitor-binding pocket adjacent to the MgATP-binding site. The presence of the potent inhibitor induces several conformational changes in the unphosphorylated MEK1 and MEK2 enzymes that lock them into a closed but catalytically inactive species. Thus, the structures reported here reveal a novel, noncompetitive mechanism for protein kinase inhibition.