Renal clear-cell carcinoma: an ultrastructural study on the junctional complexes
G. Kim1, S.A. Rajasekaran1, G. Thomas1, E.A. Rosen1, E.M. Landaw2, P. Shintaku1, C. Lassman1, J. Said1 and A.K. Rajasekaran1
1Department of Pathology and Laboratory Medicine, 2Department of Biomathematics, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, California, USA
Offprint requests to: Ayyappan K. Rajasekaran, Department of Pathology and Laboratory Medicine, Room 13-344 CHS, University of California, Los Angeles, CA 90095, USA. Fax: (310) 267-2410. e-mail: arajasekaran@mednet.ucla.edu
Summary. Junctional complexes such as tight junctions, adherens junctions, and desmosomes play crucial roles in the structure and function of epithelial cells. These junctions are involved in increasing cell-cell contact and as well serve as signaling centers regulating multiple functions in epithelial cells. Carcinoma cell lines cultured in the laboratory generally lack junctional complexes. However, studies directed towards understanding the distribution of junctional complexes in human cancer tissues are lacking. In this study, we analyzed by electron microscopy the distribution of junctional complexes in patients diagnosed with renal clear-cell carcinoma. We found that both tight junctions and adherens junctions were drastically reduced in patients with cancer compared to normal tissues. Desmosomes were not detected in normal proximal tubules while distinctly present in cancer tissues. These results suggest that analysis of junctional complexes in human tumors should provide valuable information that might have prognostic and diagnostic value. Histol Histopathol 20, 35-44 (2005)
Keywords: Tight junction, Desmosome, Adherens junction, Renal clear-cell carcinoma
DOI: 10.14670/HH-20.35