title: Determination of a potential role of the CCN family of growth regulators in connexin43 transfected C6 glioma cells.
abstract: Tumour cells often exhibit erratic cell growth, as well as decreased gap junctional intercellular communication (GJIC). C6 glioma cells are characterized by low levels of gap junction mRNA and protein, and decreased amounts of GJIC when compared with astrocytes. Previous work has shown that C6 glioma cells transfected with connexin43 (C6-Cx43) exhibit decreased proliferation in vivo and in vitro, as well as genes that are differentially expressed between these cells. In this study, RNA levels of two CCN (connective tissue growth factor [CTGF], Cyr61/Cef-10, nephroblastoma overexpressed [NOV]) gene family members are shown to be upregulated in C6-Cx43 cells: Cyr61 and Nov. Cyr61 has previously been shown to increase adhesion, migration and growth in many cell types, whereas NOV has growth suppressive capacities. Cyr61 RNA expression is shown here to respond to serum in quiescent cells in an immediate early gene fashion, independent of Cx43 expression. In contrast, Nov RNA levels remain constant, reflective of transfected Cx43 expression. Furthermore, confocal microscopy indicates that NOV colocalizes with Cx43 plaques at the cell membrane. These findings provide insight into the possible role of Nov and Cyr61 in tumour cells.
authors.affiliation: Department of Anatomy and Cell Biology, The University of Western Ontario, London, Canada.
authors.forename: T L
authors.initials: TL
authors.lastname: McLeod
authors.forename: J F
authors.initials: JF
authors.lastname: Bechberger
authors.forename: C C
authors.initials: CC
authors.lastname: Naus
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D055513:Connective Tissue Growth Factor; D018031:Connexin 43 / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D055515:Cysteine-Rich Protein 61; D017629:Gap Junctions / Q000378:metabolism; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D014407:Tumor Cells, Cultured
chemical_list: C501849:CCN1 protein, rat; C526316:CCN2 protein, rat; D018031:Connexin 43; D003470:Culture Media; D055515:Cysteine-Rich Protein 61; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D055513:Connective Tissue Growth Factor