mTOR kinase inhibitor potentiates apoptosis of PI3K and MEK inhibitors in diagnostically defined subpopulations

2012 ◽  
Vol 326 (2) ◽  
pp. 168-175 ◽  
Author(s):  
Ulka Vijapurkar ◽  
Liliane Robillard ◽  
Siqun Zhou ◽  
Michael Degtyarev ◽  
Kui Lin ◽  
...  
eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Vidhu Sharma ◽  
Lisa Young ◽  
Miguel Cavadas ◽  
Kate Owen ◽  

The Reproducibility Project: Cancer Biology seeks to address growing concerns about reproducibility in scientific research by conducting replications of selected experiments from a number of high-profile papers in the field of cancer biology. The papers, which were published between 2010 and 2012, were selected on the basis of citations and Altmetric scores (<xref ref-type="bibr" rid="bib4">Errington et al., 2014</xref>). This Registered Report describes the proposed replication plan of key experiments from “COT drives resistance to RAF inhibition through MAPK pathway reactivation” by Johannessen and colleagues, published in Nature in 2010 (<xref ref-type="bibr" rid="bib10">Johannessen et al., 2010</xref>). The key experiments to be replicated are those reported in Figures 3B, 3D-E, 3I, and 4E-F. In Figures 3B, D-E, RPMI-7951 and OUMS023 cells were reported to exhibit robust ERK/MEK activity concomitant with reduced growth sensitivity in the presence of the BRAF inhibitor PLX4720. MAP3K8 (COT/TPL2) directly regulated MEK/ERK phosphorylation, as the treatment of RPMI-7951 cells with a MAP3K8 kinase inhibitor resulted in a dose-dependent suppression of MEK/ERK activity (Figure 3I). In contrast, MAP3K8-deficient A375 cells remained sensitive to BRAF inhibition, exhibiting reduced growth and MEK/ERK activity during inhibitor treatment. To determine if RAF and MEK inhibitors together can overcome single-agent resistance, MAP3K8-expressing A375 cells treated with PLX4720 along with MEK inhibitors significantly inhibited both cell viability and ERK activation compared to treatment with PLX4720 alone, as reported in Figures 4E-F. The Reproducibility Project: Cancer Biology is collaboration between the Center for Open Science and Science Exchange and the results of the replications will be published in eLife.


2019 ◽  
Vol 317 (1) ◽  
pp. F187-F196 ◽  
Author(s):  
Sara J. Holditch ◽  
Carolyn N. Brown ◽  
Daniel J. Atwood ◽  
Andrew M. Lombardi ◽  
Khoa N. Nguyen ◽  
...  

Autosomal dominant polycystic kidney disease (PKD) is characterized by cyst formation and growth, which are partially driven by abnormal proliferation of tubular cells. Proproliferative mechanistic target of rapamycin (mTOR) complexes 1 and 2 (mTORC1 and mTORC2) are activated in the kidneys of mice with PKD. Sirolimus indirectly inhibits mTORC1. Novel mTOR kinase inhibitors directly inhibit mTOR kinase, resulting in the inhibition of mTORC1 and mTORC2. The aim of the present study was to determine the effects of sirolimus versus the mTOR kinase inhibitor torin2 on cyst growth and kidney function in the Pkd1 p.R3277C ( Pkd1RC/RC) mouse model, a hypomorphic Pkd1 model orthologous to the human condition, and to determine the effects of sirolimus versus torin2 on mTORC1 and mTORC2 signaling in PKD1−/− cells and in the kidneys of Pkd1RC/RC mice. In vitro, both inhibitors reduced mTORC1 and mTORC2 phosphorylated substrates and negatively impacted cellular metabolic activity, as measured by MTT assay. Pkd1RC/RC mice were treated with sirolimus or torin2 from 50 to 120 days of age. Torin2 was as effective as sirolimus in decreasing cyst growth and improving loss of kidney function. Both sirolimus and torin2 decreased phosphorylated S6 protein, phosphorylated eukaryotic translation initiation factor 4E-binding protein 1, phosphorylated Akt, and proliferation in Pkd1RC/RC kidneys. In conclusion, torin2 and sirolimus were equally effective in decreasing cyst burden and improving kidney function and mediated comparable effects on mTORC1 and mTORC2 signaling and proliferation in the Pkd1RC/RC kidney.


2011 ◽  
Vol 58 (2) ◽  
pp. 191-199 ◽  
Author(s):  
Peter J. Houghton ◽  
Richard Gorlick ◽  
E. Anders Kolb ◽  
Richard Lock ◽  
Hernan Carol ◽  
...  

Leukemia ◽  
2013 ◽  
Vol 28 (1) ◽  
pp. 203-206 ◽  
Author(s):  
F Guo ◽  
J Li ◽  
S Zhang ◽  
W Du ◽  
S Amarachintha ◽  
...  

2015 ◽  
Vol 26 ◽  
pp. ix37
Author(s):  
K. Sekihara ◽  
S. Yamamoto ◽  
M. Kikkawa ◽  
H. Taka ◽  
N. Kaga ◽  
...  

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