title: Aqp 9 and brain tumour stem cells.
abstract: Several studies have implicated the aquaporins (aqp) 1, 4, and 9 in the pathogenesis of malignant brain tumours, suggesting that they contribute to motility, invasiveness, and oedema formation and facilitate metabolism in tumour cells under hypoxic conditions. We have studied the expression of aqp1, 4, and 9 in biopsies from glioblastomas, isolated tumour stem cells grown in a tumoursphere assay and analyzed the progenitor and differentiated cells from these cultures. We have compared these to the situation in normal rat brain, its stem cells, and differentiated cells derived thereof. In short, qPCR in tumour tissue showed presence of aqp1, 4, and 9. In the tumour progenitor population, aqp9 was markedly more highly expressed, whilst in tumour-derived differentiated cells, aqp4 was downregulated. However, immunostaining did not reveal increased protein expression of aqp9 in the tumourspheres containing progenitor cells; in contrast, its expression (both mRNA and protein) was high in differentiated cultures. We, therefore, propose that aquaporin 9 may have a central role in the tumorigenesis of glioblastoma.
authors.affiliation: Vilhelm Magnus laboratory, Institute for Surgical Research, Norwegian National Hospital, Oslo University Hospital, 0450 Oslo, Norway.
authors.forename: Guri
authors.initials: G
authors.lastname: Fossdal
authors.forename: Einar O
authors.initials: EO
authors.lastname: Vik-Mo
authors.forename: Cecilie
authors.initials: C
authors.lastname: Sandberg
authors.forename: Mercy
authors.initials: M
authors.lastname: Varghese
authors.forename: Mari
authors.initials: M
authors.lastname: Kaarbø
authors.forename: Emily
authors.initials: E
authors.lastname: Telmo
authors.forename: Iver A
authors.initials: IA
authors.lastname: Langmoen
authors.forename: Wayne
authors.initials: W
authors.lastname: Murrell
mesh_terms: D000818:Animals; D051398:Aquaporin 1 / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D051401:Aquaporin 4 / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D020346:Aquaporins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D001921:Brain / Q000378:metabolism; D001932:Brain Neoplasms / Q000235:genetics* / Q000378:metabolism; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D005909:Glioblastoma / Q000235:genetics / Q000378:metabolism; D006801:Humans; D014411:Neoplastic Stem Cells / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
chemical_list: C109669:AQP9 protein, human; C491637:Aqp9 protein, rat; D051401:Aquaporin 4; D020346:Aquaporins; D012333:RNA, Messenger; D051398:Aquaporin 1