title: Differential regulation of glial cell line-derived neurotrophic factor (GDNF) expression in human neuroblastoma and glioblastoma cell lines.
abstract: Human SK-N-AS neuroblastoma and U-87MG glioblastoma cell lines were found to secrete relatively high levels of glial cell line-derived neurotrophic factor (GDNF). In response to growth factors, cytokines, and pharmacophores, the two cell lines differentially regulated GDNF release. A 24-hr exposure to tumor necrosis factor-alpha (TNFalpha; 10 ng/ml) or interleukin-1beta (IL-1,; 10 ng/ml) induced GDNF release in U-87MG cells, but repressed GDNF release from SK-N-AS cells. Fibroblast growth factors (FGF)-1, -2, and -9 (50 ng/ml), the prostaglandins PGA2, PGE2, and PGI2 (10 microM), phorbol 12,13-didecanoate (PDD; 10 nM), okadaic acid (10 nM), dexamethasone (1 microM), and vitamin D3 (1 microm) also differentially effected GDNF release from U-87MG and SK-N-AS cells. A result shared by both cell lines, was a two- to threefold increase in GDNF release by db-cAMP (1 mM), or forskolin (10 microM). In general, analysis of steady-state GDNF mRNA levels correlated with changes in extracellular GDNF levels in U-87MG cells but remained static in SK-N-AS cells. The data suggest that human GDNF synthesis/release can be regulated by numerous factors, signaling through multiple and diverse secondary messenger systems. Furthermore, we provide evidence of differential regulation of human GDNF synthesis/release in cells of glial (U-87MG) and neuronal (SK-N-AS) origin.
authors.affiliation: Department of Molecular and Cellular Biochemistry, Center for Biological Research, Roche Bioscience, Palo Alto, California 94304-1397, USA. neil.verity@roche.com
authors.forename: A N
authors.initials: AN
authors.lastname: Verity
authors.forename: T L
authors.initials: TL
authors.lastname: Wyatt
authors.forename: W
authors.initials: W
authors.lastname: Lee
authors.forename: B
authors.initials: B
authors.lastname: Hajos
authors.forename: P A
authors.initials: PA
authors.lastname: Baecker
authors.forename: R M
authors.initials: RM
authors.lastname: Eglen
authors.forename: R M
authors.initials: RM
authors.lastname: Johnson
mesh_terms: D001932:Brain Neoplasms / Q000378:metabolism*; D002460:Cell Line; D016207:Cytokines / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D051100:Glial Cell Line-Derived Neurotrophic Factor; D005909:Glioblastoma / Q000378:metabolism*; D006133:Growth Substances / Q000378:metabolism; D006801:Humans; D050356:Lipid Metabolism; D009414:Nerve Growth Factors / Q000096:biosynthesis*; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D009447:Neuroblastoma / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology