Altered expression of Cx43 in astrocytic tumors

Objective: To evaluate the Cx43 expression of astrocytic tumors and correlate their expression with degrees of malignancy and proliferation activity of tumors. Methods: Cx43 expression in eight normal brain tissues, 44 freshly resected astrocytic tumor specimens and four malignant glioma cell lines were examined by Northern blot analysis and immunohistochemical staining. The proliferation activity of tumors was measured by Ki67 labeling index (Ki67LI) with immunostaining. Scrape loading and dye transfer assay was used for examination of gap junction intercellular communication (GJIC) in glioma cell lines. Results: Twenty-three out of 44 astrocytic tumors (52%) expressed both Cx43 mRNA and Protein. Cx43 expression was decreased with the ascending of tumor grade and negatively correlated with Ki67LI. GJIC was interrupted in glioma cell lines deficient in Cx43 expression. Conclusions: Cx43 expression level is inversely correlated with the tumor grade and proliferation activity of tumor, suggesting the potential role of Cx43 in the malignant progression of astrocytic tumors.