Seto S.,Kyorin Pharmaceutical Co. |
Yumoto K.,Kyorin Pharmaceutical Co. |
Okada K.,Kyorin Pharmaceutical Co. |
Asahina Y.,Kyorin Pharmaceutical Co. |
And 6 more authors.
Bioorganic and Medicinal Chemistry | Year: 2012
The design, synthesis, and evaluation of 6-6-7 tricyclic quinolones containing the strained spirocycle moiety aiming at the GSK-3β inhibitor were described. Among the synthesized compounds, 44, having a cyclobutane ring on a spirocycle, showed excellent GSK-3β inhibitory activity in both cell-free and cell-based assays (IC 50 = 36 nM, EC 50 = 3.2 μM, respectively). Additionally, 44 decreased the plasma glucose concentration dose-dependently after an oral glucose tolerance test in mice. © 2011 Elsevier Ltd. All rights reserved. Source
Vetter M.L.,Harvard University |
Rodgers M.A.,Harvard University |
Rodgers M.A.,University of Southern California |
Patricelli M.P.,ActivX Biosciences Inc. |
Yang P.L.,Harvard University
ACS Chemical Biology | Year: 2012
Many cellular factors are regulated via mechanisms affecting protein conformation, localization, and function that may be undetected by most commonly used RNA- and protein-based profiling methods that monitor steady-state gene expression. Mass-spectrometry-based chemoproteomic profiling provides alternatives for interrogating changes in the functional properties of proteins that occur in response to biological stimuli, such as viral infection. Taking dengue virus 2 (DV2) infection as a model system, we utilized reactive ATP- and ADP-acyl phosphates as chemical proteomic probes to detect changes in host kinase function that occur within the first hour of infection. The DNA-dependent protein kinase (DNA-PK) was discovered as a host enzyme with significantly elevated probe labeling within 60 min of DV2 infection. Increased probe labeling was associated with increased DNA-PK activity in nuclear lysates and localization of DNA-PK in nucleoli. These effects on DNA-PK were found to require a postfusion step of DV2 entry and were recapitulated by transfection of cells with RNA corresponding to stem loop B of the DV2 5′ untranslated region. Upon investigation of the potential downstream consequences of these phenomena, we detected a modest but significant reduction in the interferon response induced by DV2 in cells partially depleted of the Ku80 subunit of DNA-PK. These findings identify changes in DNA-PK localization and activity as very early markers of DV2 infection. More broadly, these results highlight the utility of chemoproteomic profiling as a tool to detect changes in protein function associated with different cell states and that may occur on very short time scales. © 2012 American Chemical Society. Source
Liu Q.,Harvard University |
Xu C.,Ludwig Center at Dana Farber Harvard Cancer Center |
Kirubakaran S.,Harvard University |
Zhang X.,Harvard University |
And 27 more authors.
Cancer Research | Year: 2013
mTOR is a highly conserved serine/threonine protein kinase that serves as a central regulator of cell growth, survival, and autophagy. Deregulation of the PI3K/Akt/mTOR signaling pathway occurs commonly in cancer and numerous inhibitors targeting the ATP-binding site of these kinases are currently undergoing clinical evaluation. Here, we report the characterization of Torin2, a second-generation ATP-competitive inhibitor that is potent and selective for mTOR with a superior pharmacokinetic profile to previous inhibitors. Torin2 inhibited mTORC1- dependent T389 phosphorylation on S6K (RPS6KB1) with an EC50 of 250 pmol/L with approximately 800-fold selectivity for cellular mTOR versus phosphoinositide 3-kinase (PI3K). Torin2 also exhibited potent biochemical and cellular activity against phosphatidylinositol-3 kinase-like kinase (PIKK) family kinases includingATM(EC50, 28 nmol/L), ATR (EC50, 35 nmol/L), and DNA-PK (EC50, 118 nmol/L; PRKDC), the inhibition of which sensitized cells to Irradiation. Similar to the earlier generation compound Torin1 and in contrast to other reported mTOR inhibitors, Torin2 inhibited mTOR kinase and mTORC1 signaling activities in a sustained manner suggestive of a slow dissociation from the kinase. Cancer cell treatment with Torin2 for 24 hours resulted in a prolonged block in negative feedback and consequent T308 phosphorylation on Akt. These effects were associated with strong growth inhibition in vitro. Single-agent treatment with Torin2 in vivo did not yield significant efficacy against KRAS-driven lung tumors, but the combination of Torin2 with mitogen-activated protein/extracellular signal- regulated kinase (MEK) inhibitor AZD6244 yielded a significant growth inhibition. Taken together, our findings establish Torin2 as a strong candidate for clinical evaluation in a broad number of oncologic settings wheremTOR signaling has a pathogenic role. © 2013 American Association for Cancer Research. Source
ActivX Biosciences Inc. | Date: 2010-01-11
ActivX Biosciences Inc. | Date: 2011-07-05
Diagnostic preparations for scientific research use; reagents for scientific research use; assays and reagents for genetic research; reagents for use in the field of activity-based proteomics.