[Study on the variable activity of nucleolar organizer regions in lymphocytes from patients with carcinoma]

The activity of nucleolar organizer regions (NOR) in the peripheral lymphocytes from patients with lung, gastric, intestinal or breast carcinoma was studied with a combined method of Ag-staining and G-band. The frequencies of Ag-NOR were higher in chromosome 15 and sum total from patients with lung cancer, lower in chromosome 14 from patients with breast cancer, and lower in chromosome 14 but higher in chromosome 22 from patients with gastric cancer, as compared with those of controls. No significant variation of the frequencies of Ag-NOR was found in the patients with intestinal cancer. The results indicate that a dominant Ag-stained NOR model is shown in the patients with different carcinoma, i.e., the active expression of rRNA genes may present a speciality concerning the location of carcinoma.