title: Sialidase NEU4 is involved in glioblastoma stem cell survival.
abstract: The human sialidase, NEU4, has emerged as a possible regulator of neuronal differentiation and its overexpression has been demonstrated to promote the acquisition of a stem cell-like phenotype in neuroblastoma cells. In this paper, we demonstrated that glioblastoma stem cells (GSCs) isolated from glioblastoma multiforme (GBM) cell lines and patients' specimens as neurospheres are specifically marked by the upregulation of NEU4; in contrast, the expression of NEU4 is very low in non-neurosphere-differentiated GBM cells. We showed that NEU4 silencing by miRNA or a chemical inhibitor of its catalytic activity triggered key events in GSCs, including (a) the activation of the glycogen synthase kinase 3β, with the consequent inhibition of Sonic Hedgehog and Wnt/β-catenin signalling pathways; (b) the decrease of the stem cell-like gene expression and marker signatures, evidenced by the reduction of NANOG, OCT-4, SOX-2, CD133 expression, ganglioside GD3 synthesis, and an altered protein glycosylation profile; and (c) a significant decrease in GSCs survival. Consistent with this finding, increased NEU4 activity and expression induced in the more differentiated GBM cells by the NEU4 agonist thymoquinone increased the expression of OCT-4 and GLI-1. Thus, NEU4 expression and activity appeared to help to determine the molecular signature of GSCs and to be closely connected with their survival properties. Given the pivotal role played by GSCs in GBM lethality, our results strongly suggest that NEU4 inhibition could significantly improve current therapies against this tumour.
authors.affiliation: Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan), Italy.
authors.forename: I
authors.initials: I
authors.lastname: Silvestri
authors.affiliation: Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan), Italy.
authors.forename: F
authors.initials: F
authors.lastname: Testa
authors.affiliation: Medical Oncology Department, Fondazione IRCCS Istituto Nazionale per lo Studio e la Cura dei Tumori, Milan, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Zappasodi
authors.affiliation: Alberta Glycomics Center, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada.
authors.forename: C W
authors.initials: CW
authors.lastname: Cairo
authors.affiliation: Alberta Glycomics Center, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Laboratory of Molecular Pharmacology, Institute for Cancer Research and Treatment (IRCC), Candiolo (Torino), Italy.
authors.forename: B
authors.initials: B
authors.lastname: Lupo
authors.affiliation: Neural Stem Cell Biology Unit, Division of Regenerative Medicine Stem Cells and Gene Therapy, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Galli
authors.affiliation: Medical Oncology Department, Fondazione IRCCS Istituto Nazionale per lo Studio e la Cura dei Tumori, Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Di Nicola
authors.affiliation: Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan), Italy.
authors.forename: B
authors.initials: B
authors.lastname: Venerando
authors.affiliation: Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan), Italy.
authors.forename: C
authors.initials: C
authors.lastname: Tringali
mesh_terms: D000071916:AC133 Antigen; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival; D005732:Gangliosides / Q000378:metabolism; D020868:Gene Silencing; D005909:Glioblastoma / Q000378:metabolism / Q000473:pathology; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D000071317:Nanog Homeobox Protein; D014411:Neoplastic Stem Cells / Q000166:cytology / Q000378:metabolism; D009439:Neuraminidase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D055748:SOXB1 Transcription Factors / Q000235:genetics / Q000378:metabolism; D060449:Wnt Signaling Pathway
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D005732:Gangliosides; D006023:Glycoproteins; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins; D035683:MicroRNAs; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3; C000606023:PROM1 protein, human; D010455:Peptides; C509239:SHH protein, human; D055748:SOXB1 Transcription Factors; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3; C491428:NEU4 protein, human; D009439:Neuraminidase