[Ki-67 and p53 expression in gastric dysplasias and cancer]

The authors analyzed the heterogenicity of a cell population in dysplasia of varying degrees and gastric cancer from the expression of the proliferation marker Ki-67 and apoptosis activator p53 gene. Twenty-four stomachs (surgically removed for cancer) and biopsy materials (4 cases of moderate dysplasia, 4 cases of severe dysplasia) were studied. Four samples from clinically healthy individuals served as a control. The labeling index of Ki-67 in third-degree dysplasia was 37.9 +/- 2.5% and that in cancer 61.6 +/- 3.8%. There was no expression of the p53 gene in the controls. In three-degree dysplasia and cancer, the expression was 17.7 +/- 5.7% and as high as 69%, respectively. The densitometric characteristics of the labeled cells were of great diagnostic importance. Gastric cancer was represented mainly by 2 cell populations: (1) a stem cell line located in G1 with a low labeling index and a low optical density of Ki-67 and p53 and (2) an aggressive cell clone located in the S and G2 phase with marker hyperexpression.