Rat gap junction connexin-30 inhibits proliferation of glioma cell lines.
Connexins, the structural components of gap junctions, control cell growth and differentiation and are believed to belong to a family of tumour suppressor genes. Studies on connexin localization in brain showed that several of these proteins were expressed in distinct compartments of the brain in a cell-type specific manner, indicating that different gap junctions play specific roles in the physiology of the mammalian brain. In this report, we first cloned rat connexin-30 cDNA from brain and showed that it was expressed in long-term primary culture of rat astrocytes. In order to examine the potential role of connexin-30 in tumour cell proliferation, we transfected the connexin-30 cDNA into two rat glioma cell lines (9L and C6) which have lost its expression. Transfected clones adequately expressed membrane-bound connexin-30 protein. Connexin-30-expressing clones showed slower growth, lower DNA synthesis and reduced proliferation in soft agar as compared with the parental and control cells. We concluded that connexin-30 may also probably be considered as a tumour suppressor in rat gliomas.
Laboratory of Medical Chemistry and Medical Oncology, Department of Human Physiology, University of Liège, Sart-Tilman, 4000 Liège, Belgium.
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Princen
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Robe
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Gros
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Jarry-Guichard
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Gielen
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Merville
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Bours
D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D000075302:Connexin 30; D017630:Connexins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D018076:DNA, Complementary; D017629:Gap Junctions / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D051381:Rats; D017386:Sequence Homology, Amino Acid; D014162:Transfection; D014407:Tumor Cells, Cultured
D000075302:Connexin 30; D017630:Connexins; D018076:DNA, Complementary; C491020:GJB6 protein, human