[Proliferative activity in gastric cancer with Ki-67 and propidium iodide: analysis by flow cytometry]

Growth fractions in the cell cycle were demonstrated by flow cytometry with monoclonal antibody Ki-67 for gastric cancer. By setting the cut off line at the lowest channel number of S-phase, the Ki-67 labeling rate was calculated by Ki-DNA dual fluorescence analysis. In addition to 32 gastric cancers, we examined three cell lines (Colo 320, NUGC4 and MKN28) and compared the result with the BrdUrd labeling rate. The G0G1 ratio obtained with BrdUrd was generally correlated with the G0 + G1 ratio obtained with Ki-67. The S-phase fractions obtained with Ki-67, however were a little different from those obtained with BrdUrd because of the existence of S0. The mean Ki-67 labeling rate of gastric cancer was 45.1% (16.2-66.3%). Fifteen cases received Ki-67 immunohistochemical study in the same samples. The results of flow cytometric analysis were parallel to those of microscopic study, and a correlation line: y = 0.626x + 15.9145, r = 0.8031, (p less than 0.001) was obtained. Ki-67 antibodies may provide useful information on cell kinetics.