Growth regulation of astrocytes and C6 cells by TGFbeta1: correlation with gap junctions.
Transforming growth factor (TGF) beta1 enhanced in vitro [3H]thymidine incorporation into C6 cells and reduced that of astrocytes in the presence of a high serum concentration. It concomitantly raised the gap junction intercellular communication (GJIC) in normal astrocytes but reduced the coupling of C6 cells, and respectively increased or decreased the proportion of P2-phosphorylated connexin (Cx) 43 isoform in these cells. Finally, octanol, which inhibited GJIC in both cell types, increased the thymidine incorporation in C6 cells, but neither altered the proliferation of astrocytes nor their response to TGFbeta1. These data indicate that an inhibition of gap junction intercellular communication, due to an altered phosphorylation of connexin 43, may contribute to the proliferative response of C6 glioblastoma cells to TGFbeta1.
Robe
P A
PA
Department of Neurosurgery, Centre Hospitalier Universitaire de Liège, Domaine du Sart Tilman, Belgium.
Rogister
B
B
Merville
M P
MP
Bours
V
V
D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D002450:Cell Communication / Q000187:drug effects / Q000502:physiology; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D018031:Connexin 43 / Q000187:drug effects / Q000378:metabolism; D017629:Gap Junctions / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D005909:Glioblastoma / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D000442:Octanols / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013936:Thymidine / Q000378:metabolism / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000378:metabolism / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1; D014316:Tritium; D014407:Tumor Cells, Cultured / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism
D018031:Connexin 43; D000442:Octanols; C508962:Tgfb1 protein, rat; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D014316:Tritium; D013936:Thymidine