ISPO

Published in Cancer Detection and Prevention 2000; 24(Supplement 1).

Connexin43 expression decreased with tumor growth in renal cancer

M Noguchi MD, K Nomata MD, S Koga MD, H Kanetake MD

Dept Urology, Nagasaki University School of Medicine, Nagasaki, Japan, nogman@net.nagasaki-u.ac.jp

AIM: Gap junctional intercellular communication (GJIC) plays a role in development and maintenance of normal cell society, and most cancer cells have dysfunction in GJIC. This study was evaluated the alteration of connexin43 (Cx43) and GJIC in renal cell carcinoma (RCC). METHODS: Blocks of renal cancer tissue and surround normal renal tissue were taken from radical nephrectomy. GJIC was observed under an electron microscope in 16 kidneys. Northern blot analysis of Cx43, Cx32 and Cx26 and Western blot analysis of Cx43 were done. Immunohistostaining of Cx43 were examined in 28 renal cancer patients. Further, the relationship between Cx43 expression and pathological findings were examined. RESULTS: Under the electron microscope, the number of GJIC in RCC tissues was significantly less than in the surrounding normal renal tissues. In Northern analysis, Cx43 gene was highly expressed, and Cx43 gene expression in the RCC tissues was increased in comparison with the normal renal tissues. The phosphorylated form of Cx43 bands was not detectable in RCC tissue in immunoblot analysis. According to the immunohistostaining, Cx43 expressions were identified in all normal renal tubular cells. However, in RCC blocks only 8 of 28 patients expressed Cx43 and the expression was significantly week. All 8 cases expressed Cx43 were low T stage and no metastasis, and 7 of 8 patients are alive with tumor free. There is no relationship between Cx43 expression and cancer cell grading. CONCLUSIONS: Cx 43 is good prognostic marker for renal cancer.

KEY WORDS: gap junction, connexin43, renal cancer.

For more information, contact nogman@net.nagasaki-u.ac.jp

Paper presented at the International Symposium on Impact of Biotechnology on Cancer Diagnostic & Prognostic Indicators; Geneva, Switzerland; October 28 - 31, 2000; in the section on prognostic markers.

http://www.cancerprev.org/Journal/Issues/24/101/405/3275