Site of Azido Substitution in the Sugar Moiety of Azidopyrimidine Nucleosides Influences the Reactivity of Aminyl Radicals Formed by Dissociative Electron Attachment.

In this work, electron-induced site-specific formation of neutral π-type aminyl radicals (RNH·) and their reactions with pyrimidine nucleoside analogs azidolabeled at various positions in the sugar moiety, e.g., at 2'-, 3'-, 4'-, and 5'- sites along with a model compound 3-azido-1-propanol (3AZPrOH), were investigated.

Prehydrated One-Electron Attachment to Azido-Modified Pentofuranoses: Aminyl Radical Formation, Rapid H-Atom Transfer, and Subsequent Ring Opening.

Methyl 2-azido-2-deoxy-α-d-lyxofuranoside (1a) and methyl 2-azido-2-deoxy-β-d-ribofuranoside (2) were prepared from d-xylose or d-arabinose, respectively. Employing ESR and DFT/B3LYP/6-31G* calculations, we investigated (i) aminyl radical (RNH·) formation and (ii) reaction pathways of RNH·. Prehydrated electron attachment to 1a and 2 at 77 K produced transient azide anion radical (RN·) which reacts via rapid N loss at 77 K, forming nitrene anion radical (RN·).

Manic fringe inhibits tumor growth by suppressing Notch3 degradation in lung cancer.

Notch signaling plays an essential role in development as well as cancer. We have previously shown that Notch3 is important for lung cancer growth and survival. Notch receptors are activated through the interaction with their ligands, resulting in proteolytic cleavage of the receptors.

Investigation of reactions postulated to occur during inhibition of ribonucleotide reductases by 2'-azido-2'-deoxynucleotides.

Model 3'-azido-3'-deoxynucleosides with thiol or vicinal dithiol substituents at C2' or C5' were synthesized to study reactions postulated to occur during inhibition of ribonucleotide reductases by 2'-azido-2'-deoxynucleotides. Esterification of 5'-(tert-butyldiphenylsilyl)-3'-azido-3'-deoxyadenosine and 3'-azido-3'-deoxythymidine (AZT) with 2,3-S-isopropylidene-2,3-dimercaptopropanoic acid or N-Boc-S-trityl-L-cysteine and deprotection gave 3'-azido-3'-deoxy-2'-O-(2,3-dimercaptopropanoyl or cysteinyl)adenosine and the 3'-azido-3'-deoxy-5'-O-(2,3-dimercaptopropanoyl or cysteinyl)thymidine analogs. Density functional calculations predicted that intramolecular reactions between generated thiyl radicals and an azido group on such model compounds would be exothermic by 33.

Notch, apoptosis and cancer.

Proper embryonic development and normal tissue homeostasis require a series of molecular processes, regulating cell growth, differentiation and apoptosis. Perturbation in any of these processes invariably contributes to the development of cancer. In particular, defects in apoptosis are seen in virtually all types of human cancers.

Targeting notch pathway enhances rapamycin antitumor activity in pancreas cancers through PTEN phosphorylation.

Background: Pancreas cancer is one of most aggressive human cancers with the survival rate for patients with metastatic pancreas cancer at 5-6 months. The poor survival demonstrates a clear need for better target identification, drug development and new therapeutic strategies. Recent discoveries have shown that the role for Notch pathway is important in both development and cancer.

Targeting specific regions of the Notch3 ligand-binding domain induces apoptosis and inhibits tumor growth in lung cancer.

Like many signaling pathways in development, the Notch receptor pathway plays an important role in cancer pathobiology when it is dysregulated. Potential ligand-binding sites within the epidermal growth factor (EGF)-like repeats of Notch1 have been identified, but the ligand-binding domains in Notch3, which is implicated in lung cancer, are not known. In screening a library of 155 peptides representing all 34 EGF-like repeats in Notch3, we discovered two distinct ligand-binding regions involving the 7-10 and 21-22 repeats that are distinct from the putative ligand-binding domain of Notch1.

VeriStrat classifier for survival and time to progression in non-small cell lung cancer (NSCLC) patients treated with erlotinib and bevacizumab.

We applied an established and commercially available serum proteomic classifier for survival after treatment with erlotinib (VeriStrat) in a blinded manner to pretreatment sera obtained from recurrent advanced NSCLC patients before treatment with the combination of erlotinib plus bevacizumab. We found that VeriStrat could classify these patients into two groups with significantly better or worse outcomes and may enable rational selection of patients more likely to benefit from this costly and potentially toxic regimen.

Classification by mass spectrometry can accurately and reliably predict outcome in patients with non-small cell lung cancer treated with erlotinib-containing regimen.

Purpose: Although many lung cancers express the epidermal growth factor receptor and the vascular endothelial growth factor, only a small fraction of patients will respond to inhibitors of these pathways. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MS) has shown promise in biomarker discovery, potentially allowing the selection of patients who may benefit from such therapies. Here, we use a matrix-assisted laser desorption/ionization MS proteomic algorithm developed from a small dataset of erlotinib-bevacizumab treated patients to predict the clinical outcome of patients treated with erlotinib alone.

Prevalence of patch test results from 1970 to 2002 in a multi-centre population in North America (NACDG).

Background: The North American Contact Dermatitis Group (NACDG) has members who assess subjects with suspected allergic contact dermatitis (ACD) and patch tests them with the same screening allergens using a standardized procedure permitting analysis of long-term trends in patch test reactions.

Objective: This study reports the trends in prevalence patch test positivity of allergens by pooling data collected by the NACDG between 1970 and 2002.

Patients/methods: Patients were tested with the screening series of allergens, using a standardized technique.

Comedogenicity in rabbit: some cosmetic ingredients/vehicles.

The rabbit external ear canal was used to define which chemicals caused comedone formation on topical application. Some of the tested ingredients are currently used in topically applied formulations. Certain raw materials have been shown to produce follicular hyperkeratosis in the rabbit ear assay.

Efficacy and safety of single-agent pertuzumab, a human epidermal receptor dimerization inhibitor, in patients with non small cell lung cancer.

Purpose: Pertuzumab, a first-in-class human epidermal receptor 2 (HER2) dimerization inhibitor, is a humanized monoclonal anti-HER2 antibody that binds HER2's dimerization domain and inhibits HER2 signaling. Based on supporting preclinical studies, we undertook a Phase II trial of pertuzumab in patients with recurrent non-small cell lung cancer (NSCLC).

Experimental Design: Patients with previously treated NSCLC accessible for core biopsy and naive to HER pathway inhibitors were treated with pertuzumab i.

Gamma-secretase inhibitor prevents Notch3 activation and reduces proliferation in human lung cancers.

Notch receptors are key regulators of development by controlling cell-fate determination in many multicellular organisms. Genes that are important for normal differentiation play a role in cancer when their normal functions became dysregulated. Notch signaling has been shown to promote and maintain survival of many types of cancers, and we previously have shown that Notch3 plays an important role in lung cancer.

Dominant-negative Notch3 receptor inhibits mitogen-activated protein kinase pathway and the growth of human lung cancers.

Notch3 is a member of an evolutionarily conserved family of cell surface receptors important in cell-fate determination in both vertebrates and invertebrates. Significant data support the role of Notch pathway in cancer development, although the conflicting role of Notch signaling pathways in tumorigenesis suggests that its action is highly context-dependent. Furthermore, although Notch receptors signal primarily through the regulation of hairy enhancer of split (HES) and HES-related (HRT) genes, they are known to crosstalk with other signaling pathways, including the epidermal growth factor (EGF) and the mitogen-activated protein kinase pathways.

Dominant factor XI deficiency caused by mutations in the factor XI catalytic domain.

The bleeding diathesis associated with hereditary factor XI (fXI) deficiency is prevalent in Ashkenazi Jews, in whom the disorder appears to be an autosomal recessive condition. The homodimeric structure of fXI implies that the product of a single mutant allele could confer disease in a dominant manner through formation of heterodimers with wild-type polypeptide. We studied 2 unrelated patients with fXI levels less than 20% of normal and family histories indicating dominant disease transmission.

A training-testing approach to the molecular classification of resected non-small cell lung cancer.

Purpose: RNA expression patterns associated with non-small cell lung cancer subclassification have been reported, but there are substantial differences in the key genes and clinical features of these subsets casting doubt on their biological significance.

Experimental Design: In this study, we used a training-testing approach to test the reliability of cDNA microarray-based classifications of resected human non-small cell lung cancers (NSCLCs) analyzed by cDNA microarray.

Results: Groups of genes were identified that were able to differentiate primary tumors from normal lung and lung metastases, as well as identify known histological subgroups of NSCLCs.

Constitutive activation of Notch3 inhibits terminal epithelial differentiation in lungs of transgenic mice.

Notch3 is a transmembrane receptor and a member of the Notch signaling pathway essential for cellular differentiation in a variety of developing tissues in both invertebrates and vertebrates. Emerging data support the role of the Notch signaling pathway in tumorigenesis. We have previously demonstrated the expression of Notch3 in a subset of lung adenocarcinomas.