Different expression of nm23-H1 and nm23-H2 protein with proliferative activities in various sizes of human renal cell carcinoma.

Ninety-five paraffin blocks of renal cell carcinomas (RCCs) and background normal tissue were obtained from patients in Nara Medical University Hospital and used for studying silver-binding nucleolar organizer regions (AgNORs), proliferating cell nuclear antigen (PCNA) and nm23 oncogenes. The RCCs were grouped by size (< or = 30, > 30 and < or = 50, > 50 mm of average diameter) and grade according to the General Rules for Clinical and Pathological Studies of Renal Cell Carcinoma, Japan. Numbers of cases were 17 in the < or = 30-mm group, 36 in the > 30- and < or = 50-mm group, and 42 in the > 50-mm group. AgNOR scores were 4.68 +/- 1.22, 3.91 +/- 1.31 and 3.01 +/- 1.05, respectively, with significant intergroup differences. Frequencies of PCNA-positive cells per 500 cells were 33.8 +/- 23.5, 39.4 +/- 13.8 and 45.9 +/- 38.8. nm23-H1 immunohistochemical staining proved strongly positive in 21 of 24 areas of normal proximal convoluted tubules, 4 of 8 dysplasia cases, 2 of 17 in the < or = 30-mm group RCCs, 1 of 36 in the > 30- and < or = 50-mm group RCCs and none of 42 in the > 50-mm RCCs. nm23-H2 in contrast was weakly positive in 3/24, 2/8, 12/17, 30/36 and 20/42 of the cases, respectively. The results indicated an inverse relationship between tumor size and score of AgNOR without any variation in PCNA labeling and contrasting expression of nm23-H1 and nm23-H2 linked to the size of RCCs.