In Vivo Growth of C6 Glioma Cells Transfected with Connexin43 cDNA

In order to examine the possible role of intercellular communicationvia gap junctions in the control of tumor growth, we have transfected ('ftglioma cells with connexin43 cDNA. We obtained several clones withvariable expression of connexin43. The growth rate of these clones inculture was inversely related to the degree of expression of the transfected cDNA. To examine the growth of these transfected cells in vivo, cells were grown in spinner culture flasks to form spheroids 250-300 urnin diameter. Spheroids of nontransfected C6 cells produced large (¡lidmas. Immunohistochemical and in situ hybridization analyses revealedrelatively high levels of connexin43 protein and mRNA in the hosttissue, while little of this protein was detected in the glioma. In contrast, spheroids of connexin43-transfected cells grew more slowly and exhibited elevated levels of connexin43 protein and mRNA. These findingssuggest that the expression of connexin43 may be associated with thecontrol of brain tumor growth in vivo.