Enzastaurin induces H2AX phosphorylation to regulate apoptosis via MAPK signalling in malignant glioma cells
1Department of Neurosurgery, University of Pittsburgh School of Medicine, University of Pittsburgh Cancer Institute Brain Tumor Center, Pittsburgh, PA 15213, USA.
Abstract:
Enzastaurin is an acyclic bisindolylmaleimide derived from staurosporine that acts as an ATP competitor, and interferes with the activity of protein kinase C (PKC) isoforms. Our previous studies have shown that clinically achievable concentrations of this agent induce apoptosis in many glioma cell lines. Our goal in this study was to expand on the previous results and to determine the signalling mechanisms responsible for enzastaurin-induced inhibition of cell growth and induction of apoptosis. To address these issues, cell cycle progression following enzastaurin treatment was analysed by fluorescence-activated cell sorting (FACS) in parallel with analyses of growth and apoptosis signalling pathways. Enzastaurin treatment activated H2AX and Chk2 phosphorylation, and enhanced phosphorylation of mitogen-activated protein kinase (MAPK) family kinases. Inhibition of MAP kinases by chemical inhibitors reduced H2AX and Chk2 phosphorylation and decreased apoptosis induced by enzastaurin. These data call attention to a novel signalling pathway (MAPK/H2AX) to regulate apoptosis in malignant glioma cells.
Related Concept Videos
The Intrinsic Apoptotic Pathway
mTOR Signaling and Cancer Progression
The mTOR pathway or the...
mTOR Signaling and Cancer Progression
The mTOR pathway or the...
PI3K/mTOR/AKT Signaling Pathway
MAPK Signaling Cascades
Interactions Between Signaling Pathways
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...

