Dose‐dependent proteomic analysis of glioblastoma cancer stem cells upon treatment with γ‐secretase inhibitor

Abstract

Notch Signaling has been demonstrated to have a central role in Glioblastoma (GBM) Cancer Stem Cells (CSCs) and we have demonstrated recently that Notch pathway blockade by γ-secretase inhibitor (GSI) depletes GBM CSCs and prevents tumor propagation both in vitro and in vivo. In order to understand the proteome alterations involved in this transformation, a dose-dependent quantitative mass spectrometry (MS) based proteomic study has been performed based on global proteome profiling and a target verification phase where both Immunoassay and a Multiple Reaction Monitoring (MRM) assay are employed. The selection of putative protein candidates for confirmation poses a challenge due to the large number of identifications from the discovery phase. A multilevel filtering strategy together with literature mining is adopted to transmit the most confident candidates along the pipeline. Our results indicate that treating GBM CSCs with GSI induces a phenotype transformation towards non-tumorigenic cells with decreased proliferation and increased differentiation, as well as elevated apoptosis. Suppressed glucose metabolism and attenuated NFR2-mediated oxidative stress response are also suggested from our data, possibly due to their crosstalk with Notch Signaling. Overall, this quantitative proteomic based dose-dependent work complements our current understanding of the altered signaling events occurring upon the treatment of GSI in GBM CSCs.

Notch signaling in the pathogenesis, progression and identification of potential targets for cholangiocarcinoma (Review)

“…The potential of the aforementioned interventions for the control of other types of cancer has also been demonstrated. These include cinobufagin for osteosarcoma ( 57 ), xanthohumol for hepatocarcinoma ( 58 ), FLI-06 for tongue cancer ( 59 ), GSI for glioblastoma cancer stem cells ( 60 ), T-cell for acute lymphoblastic leukemia ( 61 ), osteosarcoma ( 62 ) and triple-negative breast cancer ( 63 ), and DAPT for glioma ( 64 ), colorectal cancer ( 65 ), cervical cancer ( 66 ), gastric cancer ( 67 ), head/neck squamous cell carcinoma ( 68 ), osteosarcoma ( 69 ), choriocarcinoma ( 70 ) and ovarian cancer ( 71 ). In addition, miRNA-34a has also been reported to inhibit the progression of pancreatic cancer and medulloblastoma ( 72 , 73 ), and siRNA interference has been reported to inhibit cell proliferation in glioblastoma multiforme ( 74 ).…”

Unlocking the Secrets of Cancer Stem Cells with γ-Secretase Inhibitors: A Novel Anticancer Strategy

“…Upon the usage of different concentrations of GSI-18 in vitro and in vivo, two studies reported a reduction in Hes1 protein and mRNA levels in DAOY cells, the suppression of clonogenicity, and the induction of anticancer effects mediated by suppression of the Notch signaling pathway [ 57 ], and the induction of a phenotype transformation towards non-tumorigenic cells, along with a decrease in proliferation and increase in differentiation, as well as apoptosis [ 58 ].…”

From pathways to networks: Connecting dots by establishing protein–protein interaction networks in signaling pathways using affinity purification and mass spectrometry

“…With these quantitative methods in hand, ligand‐induced receptor signaling pathways, which can be easily manipulated by external ligand stimulation or treatment with inhibitors, are now being studied. For example, using a γ‐secretase inhibitor to block Notch signaling, Dai et al profiled dose‐dependent protein expression in glioblastoma cancer stem cells . Treating Madin‐Darby canine kidney epithelial cells with TGF‐β ligand, Shen et al profiled the plasma membrane proteins and found Wnt‐5a involved in H‐Ras/TGF‐mediated epithelial‐mesenchymal transition .…”