Growth factors derived from a human malignant glioma cell line, U-251MG.
A human malignant glioma cell line, U-251 Mg, cultured under serum free conditions, was shown to produce a growth factor for BALB/c 3T3 cells (glioma-derived growth factor-1, GDGF-1). The biological activity of GDGF-1 resided in a heat- and acid-resistant protein with a molecular weight (MW) of 25 kDa estimated by gel permeation chromatography. GDGF-1 activity was neutralized by a goat anti-human platelet derived growth factor (PDGF) antibody, indicating that the two factors were immunologically related. Furthermore, U-251 Mg cells constitutively expressed c-sis mRNA. When U-251 Mg cells were stimulated with bacterial lipopolysaccharide, 2 novel growth factors (GDGF-2 and GDGF-3) were produced in addition to the PDGF-like substance. GDGF-2 was determined to be greater than 100 kDa MW and was not neutralized by the goat anti-PDGF antiserum. The biological activity of GDGF-3 was also heat- and acid-resistant with an apparent 14 kDa MW. This factor also did not show any common antigenicity with PDGF. GDGF-2 and GDGF-3 are currently under investigation and evidence as to their natures will be published elsewhere. Our findings with this glioma cell line provide further evidence that inappropriate expression of growth factor-related genes could play important autocrine role(s) in the processes leading to malignant transformation and/or uncontrolled proliferation and may provide a paracrine stimulus for such processes as glioma neovascularization.
Kuratsu
J
J
Department of Neurological Surgery, Kumamoto School of Medicine, Kumamoto University, Japan.
Estes
J E
JE
Yokota
S
S
Mahaley
M S
MS
Gillespie
G Y
GY
D000818:Animals; D015152:Blotting, Northern; D002850:Chromatography, Gel; D003429:Cross Reactions; D003470:Culture Media; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D005910:Glioma / Q000032:analysis* / Q000378:metabolism; D006133:Growth Substances / Q000032:analysis* / Q000096:biosynthesis / Q000502:physiology; D006801:Humans; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D009693:Nucleic Acid Hybridization; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D014407:Tumor Cells, Cultured / Q000032:analysis* / Q000187:drug effects / Q000378:metabolism
D003470:Culture Media; D006133:Growth Substances; D008070:Lipopolysaccharides; D012313:RNA; D004247:DNA; D003513:Cycloheximide