Inhibition of connexin 43 synthesis by antisense RNA in rat glioma cells.
The 9L rat glioma cells communicate via gap junctions which are formed of connexin 43. The gap junctional communication was inhibited in these cells by transfecting them with an antisense Cx43 DNA construct, and its effect on their growth rate was investigated. This construct was induced by a Zn(2+)-inducible metallothionein promoter. Results showed that the induction of antisense RNA expression in rat 9L glioma cells produced the loss of gap junctions which was reflected in the loss of gap junctional communication. By inducing the antisense construct with zinc acetate, and using specific antibodies to connexin 43, the synthesis of this connexin was inhibited in the transfected cells and gap junctions were lost on the cell-cell appositions. There was no such effect on the untransfected cells. The loss of gap junctions at cell-cell appositions also correlated with the loss of Lucifer yellow fluorescent dye transfer between the cells. The effect of loss of gap junctions on the growth rate of the cells was assessed. In spite of the drastic decrease in the number of gap junctions between cells, their growth rate was only approximately 20% less than that of the transfected but non-induced cells. Therefore, gap junction communication is not negatively related to the rate of growth of these cells.
Singh
M V
MV
Department of Biological Sciences, University of Alberta, Edmonton, Canada.
Bhatnagar
R
R
Malhotra
S K
SK
D000818:Animals; D002450:Cell Communication / Q000502:physiology; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D018031:Connexin 43 / Q000235:genetics*; D017629:Gap Junctions / Q000737:chemistry / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects / Q000502:physiology*; D005910:Glioma; D010957:Plasmids; D016372:RNA, Antisense / Q000494:pharmacology*; D051381:Rats; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000737:chemistry / Q000473:pathology / Q000502:physiology; D015032:Zinc / Q000494:pharmacology
D018031:Connexin 43; D016372:RNA, Antisense; D015032:Zinc