AgNOR proteins as a parameter of the rapidity of cell proliferation.

A series of studies on the relationship between AgNOR quantity and cell kinetics have been reviewed. The results indicate that the quantity of interphase AgNORs, evaluated by morphometric analysis, increases in cycling cells from early G1-phase to the late S-phase. In cancer tissues the AgNOR value is also closely related to both the percentage of cycling cells (measured by Ki67 or PCNA immunolabelling) and S-phase cells (measured by BrdU incorporation or DNA flow cytometry). Data from cell lines cultured in vitro have clearly shown that interphase AgNOR quantity is related to cell doubling time: the faster the rapidity of cell proliferation, the greater the interphase AgNOR quantity.