TY - JOUR T1 - The Preventive Effect of Green Tea on the Gap Junction Intercellular Communication in Renal Epithelial Cells Treated with a Renal Carcinogen JF - Anticancer Research JO - Anticancer Res SP - 3757 LP - 3762 VL - 24 IS - 6 AU - HAJIME TAKAHASHI AU - KOICHIRO NOMATA AU - KEN-ICHI MORI AU - MANABU MATSUO AU - TAISHI MIYAGUCHI AU - MITSURU NOGUCHI AU - HIROSHI KANETAKE Y1 - 2004/11/01 UR - http://ar.iiarjournals.org/content/24/6/3757.abstract N2 - Objective: Clinical studies imply that (-)-epigallocatechin-3-gallate (EGCG), a main ingredient of green tea catechins, has a chemopreventive action against cancers and suppresses the proliferation of cancer cells. However, there is no report about its chemopreventive effect for renal cancer. We previously determined that renal carcinogens suppressed the gap junction intercellular communication (GJIC) of renal epithelial cells. In this study, we investigated the effect of EGCG on the GJIC of renal epithelial cells treated with a renal carcinogen. Materials and Methods: Mardin-Darby canine kidney (MDCK) cells were used to determine the protective effects of EGCG on dimethylnitrosamine-induced alteration of GJIC and connexin 43 (Cx 43). The maximum concentration of EGCG was determined by the lactate dehydrogenase assay method. The scrape-loading dye transfer method was used to assess the expression and cellular localization of Cx 43. The phosphorylation status of Cx 43 was determined by Western blot analysis. Results: The optimal noncytotoxic concentration of EGCG was determined to be 10 μg/ml. The levels of GJIC and Cx 43 expression were markedly decreased in MDCK cells exposed to dimethylnitrosamine. A 12-h pretreatment with EGCG greatly ameliorated the GJIC-inhibitory effects of dimethylnitrosamine. Conclusion: These results suggest that the preservation of GJIC may indicate the chemopreventive effect of green tea on renal epithelial cells treated with a renal carcinogen in vitro. Copyright© 2004 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved ER -