Nucleolar organizer regions in hepatocellular carcinoma related to the cell cycle, cell proliferation and histologic...

In order to clarify factors which relate to AgNOR in hepatocellular carcinoma (HCC), AgNOR numbers and the expression of Ki-67 using MIB-1 antibody have been studied in paraffin-embedded specimens of 20 HCCs by means of a double staining method. We found that in individual cases the AgNOR number of MIB-1-positive cells was significantly higher than that of MIB-1-negative cells (p < 0.001). In addition, a significant correlation was seen between MIB-1 labelling index and the total mean AgNOR number (t-AgNOR) (r = 0.882, p < 0.001). The value of t-AgNORs was significantly higher in histologically less differentiated HCC (p < 0.005). The mean AgNOR number of MIB-1-negative cells (n-AgNOR) was also significantly higher in histologically less differentiated HCC (p < 0.04). By contrast, the mean AgNOR number of MIB-1-positive cells (p-AgNOR) did not significantly correlate with histologic grades (p = 0.265). However, the number of t-AgNORs was not significantly different between diploid and aneuploid tumours. In HCCs, it appears that AgNOR numbers were variably influenced by proliferative activities of tumour cells, phases of cell cycle and cell differentiation.