TY - JOUR
T1 - Combined PDK1 and CHK1 inhibition is required to kill glioblastoma stem-like cells in vitro and in vivo
AU - Signore, M.
AU - Pelacchi, F.
AU - Di Martino, S.
AU - Di Martino, Susanna
AU - Runci, D.
AU - Biffoni, M.
AU - Giannetti, Stefano
AU - Morgante, Liliana
AU - De Majo, M.
AU - Petricoin, E. F.
AU - Stancato, L.
AU - Larocca, Luigi Maria
AU - De Maria Marchiano, Ruggero
AU - Pallini, Roberto
AU - Ricci-Vitiani, L.
PY - 2014
Y1 - 2014
N2 - Glioblastoma (GBM) is the most common and deadly adult brain tumor. Despite aggressive surgery, radiation, and chemotherapy, the life expectancy of patients diagnosed with GBM is ∼14 months. The extremely aggressive nature of GBM results from glioblastoma stem-like cells (GSCs) that sustain GBM growth, survive intensive chemotherapy, and give rise to tumor recurrence. There is accumulating evidence revealing that GSC resilience is because of concomitant activation of multiple survival pathways. In order to decode the signal transduction networks responsible for the malignant properties of GSCs, we analyzed a collection of GSC lines using a dual, but complementary, experimental approach, that is, reverse-phase protein microarrays (RPPMs) and kinase inhibitor library screening. We treated GSCs in vitro with clinically relevant concentrations of temozolomide (TMZ) and performed RPPM to detect changes in phosphorylation patterns that could be associated with resistance. In addition, we screened GSCs in vitro with a library of protein and lipid kinase inhibitors to identify specific targets involved in GSC survival and proliferation. We show that GSCs are relatively insensitive to TMZ treatment in terms of pathway activation and, although displaying heterogeneous individual phospho-proteomic profiles, most GSCs are resistant to specific inhibition of the major signaling pathways involved in cell survival and proliferation. However, simultaneous multipathway inhibition by the staurosporin derivative UCN-01 results in remarkable inhibition of GSC growth in vitro. The activity of UCN-01 on GSCs was confirmed in two in vivo models of GBM growth. Finally, we used RPPM to study the molecular and functional effects of UCN-01 and demonstrated that the sensitivity to UCN-01 correlates with activation of survival signals mediated by PDK1 and the DNA damage response initiated by CHK1. Taken together, our results suggest that a combined inhibition of PDK1 and CHK1 represents a potentially effective therapeutic approach to reduce the growth of human GBM.
AB - Glioblastoma (GBM) is the most common and deadly adult brain tumor. Despite aggressive surgery, radiation, and chemotherapy, the life expectancy of patients diagnosed with GBM is ∼14 months. The extremely aggressive nature of GBM results from glioblastoma stem-like cells (GSCs) that sustain GBM growth, survive intensive chemotherapy, and give rise to tumor recurrence. There is accumulating evidence revealing that GSC resilience is because of concomitant activation of multiple survival pathways. In order to decode the signal transduction networks responsible for the malignant properties of GSCs, we analyzed a collection of GSC lines using a dual, but complementary, experimental approach, that is, reverse-phase protein microarrays (RPPMs) and kinase inhibitor library screening. We treated GSCs in vitro with clinically relevant concentrations of temozolomide (TMZ) and performed RPPM to detect changes in phosphorylation patterns that could be associated with resistance. In addition, we screened GSCs in vitro with a library of protein and lipid kinase inhibitors to identify specific targets involved in GSC survival and proliferation. We show that GSCs are relatively insensitive to TMZ treatment in terms of pathway activation and, although displaying heterogeneous individual phospho-proteomic profiles, most GSCs are resistant to specific inhibition of the major signaling pathways involved in cell survival and proliferation. However, simultaneous multipathway inhibition by the staurosporin derivative UCN-01 results in remarkable inhibition of GSC growth in vitro. The activity of UCN-01 on GSCs was confirmed in two in vivo models of GBM growth. Finally, we used RPPM to study the molecular and functional effects of UCN-01 and demonstrated that the sensitivity to UCN-01 correlates with activation of survival signals mediated by PDK1 and the DNA damage response initiated by CHK1. Taken together, our results suggest that a combined inhibition of PDK1 and CHK1 represents a potentially effective therapeutic approach to reduce the growth of human GBM.
KW - DNA damage
KW - PDK1
KW - glioblastoma stem-like cells
KW - kinase inhibitors
KW - phospho-proteomics
KW - DNA damage
KW - PDK1
KW - glioblastoma stem-like cells
KW - kinase inhibitors
KW - phospho-proteomics
UR - http://hdl.handle.net/10807/111345
U2 - 10.1038/cddis.2014.188
DO - 10.1038/cddis.2014.188
M3 - Article
SN - 2041-4889
SP - N/A-N/A
JO - CELL DEATH & DISEASE
JF - CELL DEATH & DISEASE
ER -