Zhao J.,Merck |
Ramos R.,Merck And Co. |
Demma M.,Merck And Co.
Oncogene | Year: 2013
Activation of the Wnt/β-catenin pathway is a critical step in the development of colorectal cancers. A key mediator of this activation is the recently described oncogene CDK8, which is amplified in a large number of colorectal tumors. CDK8 affects β-catenin activation by interaction of the CDK8 submodule of the mediator complex with β-catenin/TCF transcriptional complex, and by CDK8 interacting with and phosphorylating E2F1, which acts as a repressor of β-catenin/TCF transcriptional activity. The amino-acid residue in E2F1 that CDK8 phosphorylates and how this phosphorylation impacts E2F1 activity in general is not known. Here, we describe that CDK8 phosphorylates serine 375 in E2F1 both in vitro and in cells, and that phosphorylation of this residue is required for E2F1 interaction with CDK8, and that the phosphorylation is dependent on CDK8 kinase activity. The phosphorylation of S375 by CDK8 regulates E2F1 ability to repress transcription of β-catenin/TCF-dependent genes, as well as activation of E2F1-dependent genes. This regulation is due to inactivation of E2F1 transcriptional activation, and not to the interference of E2F1's ability to bind to E2F1-binding sites in various promoters or to interact with DP1. © 2013 Macmillan Publishers Limited.
Roemer T.,Merck |
Davies J.,University of British Columbia |
Giaever G.,University of Toronto |
Nislow C.,University of Toronto
Nature Chemical Biology | Year: 2012
The serendipitous discovery of penicillin inspired intensive research into how small molecules affect basic cellular processes and their potential to treat disease. Biochemical and genetic approaches have been fundamental for clarifying small-molecule modes of action. Genomic technologies have permitted the use of chemical-genetic strategies that comprehensively study compound-target relationships in the context of a living cell, providing a systems biology view of both the cellular targets and the interdependent networks that respond to chemical stress. These studies highlight the fact that in vitro determinations of mechanism rarely translate into a complete understanding of drug behavior in the cell. Here, we review key discoveries that gave rise to the field of chemical genetics, with particular attention to chemical-genetic strategies developed for bakers' yeast, their extension to clinically relevant microbial pathogens, and the potential of these approaches to affect antimicrobial drug discovery. © 2011 Nature America, Inc. All rights reserved.
Human vaccines & immunotherapeutics | Year: 2012
The pseudo-neutralization assay (PsV) described in the current report allows for the creation of HPV18 pseudovirions in order to evaluate whether the antibody responses elicited following vaccination with Gardasil(®) are sufficient to neutralize the activity of these pseudovirions in vitro. The PsV assay evaluates a broader antibody response than the HPV competitive Lumniex Immunoassay (cLIA), which monitors the presence of a single neutralizing epitope. We employed two different approaches to the HPV18-PsV assay: one using standard dilutions of heat inactivated serum from vaccinated subjects, as is typically reported in the literature, and the other using heat inactivated serum from which IgG antibodies were purified and quantitated as an attempt to reduce assay background and achieve a level of quantitation greater than that afforded through simple dilution. Here, we show that after 48 mo, Gardasil(®) vaccinated subjects from three groups defined by HPV 18 cLIA titer have detectable HPV18 neutralizing antibodies as measured by either approach in the HPV18-PsV assay. These data support the observed sustained HPV18 protection against persistent infection and disease with the absence of breakthrough cases in Gardasil(®) vaccinees and suggests that neutralizing antibodies are present although they may no longer be detectable by cLIA.
Leucht S.,TU Munich |
Journal of Psychopharmacology | Year: 2014
Objective: The purpose of this study was to assess whether early symptom improvement predicts later treatment outcome in patients with schizophrenia. Methods: Data were pooled from intent-to-treat (ITT) populations of three six-week randomized controlled studies with fixed doses of asenapine (ASE; n=470), olanzapine (OLA; n=95), risperidone (RIS; n=56), haloperidol (HAL; n=112), or placebo (PLA; n=275). Early improvement was defined as a 20% reduction of Positive and Negative Syndrome Scale (PANSS) total score at week 2, compared to baseline (primary criterion). Treatment outcome at week 6 was defined as response (PANSS: ≥50% score reduction) or remission (PANSS item score ≤3 on selected items at week 6). Odds ratios (ORs) and predictive performance statistics were calculated. Results: Statistically significant associations between early improvement (at week 2) and treatment outcome (at week 6) were observed for all treatment groups except OLA; as evidenced by increased ORs for response. Analysis of associations between early improvement and remission, as defined by Andreasen et al. (2005), revealed a statistically significant relationship for ASE and PLA-treated patients only. Predictive performance statistics revealed higher negative predictive value (NPV) and sensitivity rates, and comparably lower positive predictive value (PPV) and specificity rates across treatment groups for both response and remission. Conclusion: It is suggested that absence of improvement within two weeks of treatment may predict the unlikely success of subsequent pharmacological intervention.
Annals of the American Thoracic Society | Year: 2013
There is a long history of productive collaboration between biomedical scientists in academia and in the pharmaceutical industry. The primary beneficiary of this collaboration has been the public. Since the middle of the last century, marked advances in the treatment and prevention of disease have been driven by the translational research interactions across these two domains. But now, at a time when collaboration between academia and industry should be accelerating based on past success, new technology, and ever-increasing need, numerous obstacles to effective collaboration have appeared. In this analysis, based on experience in both academia and industry, the author provides perspective on current obstacles to academic-industrial collaboration, followed by recommendations on how effective collaboration can be renewed and enhanced. Copyright © 2013 by the American Thoracic Society.