Reduced connexin43 expression in high-grade human brain glioma cells

Background and Objectives: Connexin43 (cx43), a gap junction protein, is im plicated in the suppression of tumor cell growth. Numerous cancer cells sho w a reduction or loss of cx43 expression compared to their normal counterpa rts. Our previous studies suggest that cx43 expression is de creased in a v ariety of human brain tumor cell lines. To further investigate the role of cx43 in the development of human gliomas, we performed the present study on human glioma grades I-IV. Methods: Immunohistochemistry was performed on paraffin-embedded tissue sec tions of 18 human gliomas to analyze the expression levels of cx43 in diffe rent stages of human gliomas. Results: High levels of cx43 were observed in all normal brain tissue and i n glioma grades I and II. In contrast, the expression of cx43 was very weak in grade III gliomas and almost undetectable in grade IV gliomas. Conclusions: Our data support the hypothesis that reduction of cx43 is invo lved in the progression of human gliomas. J. Surg. Oncol. 1999:70:21-24. (C ) 1999 Wiley-Liss, Inc.