Proteomic analysis of human sonic hedgehog (SHH) medulloblastoma stem-like cells

Abstract

Human medulloblastoma (MB) is a malignant brain tumor that comprises four distinct molecular subgroups including the Sonic Hedgehog (SHH)-MB group. A leading cause of the SHH subgroup is an aberrant activation of the SHH pathway, a developmental signaling that regulates postnatal development of the cerebellum by promoting the mitotic expansion of granule neural precursors (GNPs) in the external granule layer (EGL). The abnormal SHH signaling pathway drives not only SHH-MB but also its cancer stem-like cells (SLCs), which represent a fraction of the tumor cell population that maintain cancer growth and have been associated with high grade tumors. Here, we report the first proteomic analysis of human SHH-MB SLCs before and after Retinoic Acid (RA)-induced differentiation. A total of 994 nLC-MS buckets were statistically analysed returning 68 modulated proteins between SLCs and their differentiated counterparts. Heat Shock Protein 70 (Hsp70) was one of the proteins that characterized the protein profile of SLCs. By means of Ingenuity Pathway Analysis (IPA), Genomatix analysis and extending the network obtained using the differentially expressed proteins we found a correlation between Hsp70 and the NF-κB complex. A key driver of the SHH-MB group is cMET whose downstream proliferation/survival signalling is indeed via PI3K/Akt/NF-κB. We confirmed the results of the proteomic analysis by western blot, underlining that a P-p65/NF-κB activatory complex is highly expressed in SLCs. Taking together these results we define a new protein feature of SHH-MB SLCs.

Proteomic Characterization of a New asymmetric Cellulose Triacetate Membrane for Hemodialysis

“…Adsorption of plasma proteins onto a biomaterial surface, besides affecting the removal capacity, is in particular vital to the biocompatibility of a membrane, since surface‐adsorbed proteins are of critical importance for the ensuing biological reactions that take place during the HD session, including activation of blood cells, plasma proteins, coagulation, and the complement system . Notably, current proteomic analyses allow us not only to identify and quantify the proteins present in a given sample (blood, UF, eluates), but also to visualize through bioinformatics tools the involvement of detected compounds in metabolic pathways and other biological networks …”

Understanding cell signaling in cancer stem cells for targeted therapy – can phosphoproteomics help to reveal the secrets?

“…Recently, the proteome of sonic hedgehog driven human medulloblastoma stem-like cells was analyzed before and after retinoic acid differentiation [116]. The stem-like cells isolated from human infant medulloblastoma samples were further cultured as neurospheres in selective medium.…”

Sonic Hedgehog Medulloblastoma Cancer Stem Cells Mirnome and Transcriptome Highlight Novel Functional Networks

“…Goodrich et al [19] established a model based on the mutation of Ptch , the transmembrane receptor of SHH that also functions as a tumor suppressor and reported that a subset of Ptch heterozygotes spontaneously develops MB. We previously isolated CSCs from human and murine Ptch heterozygous SHH MB [20,21,22,23] and we demonstrated that they share common features with NSCs derived from postnatal cerebellum [20]. Indeed, SHH MB CSCs and NSCs are both sustained by the Hedgehog (HH) signaling pathway using the glioma-associated oncogene homolog to up-regulate the stemness factor Nanog [20].…”

“…Indeed, SHH MB CSCs and NSCs are both sustained by the Hedgehog (HH) signaling pathway using the glioma-associated oncogene homolog to up-regulate the stemness factor Nanog [20]. Moreover, we showed that NFκB (Nuclear factor Kappa B DNA binding subunit), a transcription regulator, has a role in the sustenance of human SHH MB CSCs [21]. Interestingly, we identified several upstream regulators of NFκ B [21] such as NPM (Nucleophosmin), PCNA (Proliferating Nuclear Antigen), P65 (Nuclear Factor Kappa B Transcription Factor P65), and HSPA1A (Heat Shock Protein Family A [Hsp70] Member 1A) potentially involved in the induction of aberrant cell growth and proliferation in human SHH MB CSCs through the combined analysis of proteomics and microRNA (miRNA) expression profiles [22].…”

“…Moreover, we showed that NFκB (Nuclear factor Kappa B DNA binding subunit), a transcription regulator, has a role in the sustenance of human SHH MB CSCs [21]. Interestingly, we identified several upstream regulators of NFκ B [21] such as NPM (Nucleophosmin), PCNA (Proliferating Nuclear Antigen), P65 (Nuclear Factor Kappa B Transcription Factor P65), and HSPA1A (Heat Shock Protein Family A [Hsp70] Member 1A) potentially involved in the induction of aberrant cell growth and proliferation in human SHH MB CSCs through the combined analysis of proteomics and microRNA (miRNA) expression profiles [22]. The importance of HH–GLI signaling in tumour maintenance and stemness properties [24] has been also described in other CSC contexts, such as colon and lung cancer, in various ways for instance through a non-canonical signalling, involving NRP2 (Neuropilin 2) and MAP/ERK (Mitogen Activated Protein Kinase/Extracellular Signal-Regulated Kinase) signalling [25].…”