Evidence for quiescent S- and G2-phase cells in human colorectal carcinomas: a flow cytometric study with the Ki-67 antibody.
The expression of certain antigens specific for proliferating cells can be determined simultaneously with cell cycle distribution by means of two-dimensional flow cytometry. In this way, a tumour's growth potential is characterized more precisely than with any one parameter alone. Here we describe such simultaneous measurements of DNA content and labelling with the Ki-67 antibody that distinguishes between cycling and non-cycling cells. Having overcome a number of technical problems we were able to analyse material from 29 biopsies of human colorectal tumours. In a number of cases, Ki-67 negative cells were found with a DNA-content of G0/1 only, whereas all cells with an S- or G2-phase DNA-content were Ki-67 positive. There were other cases in which cells with an S- and G2-phase DNA-content had obviously become quiescent (Ki-67 negative), sometimes even outnumbering the proliferating (Ki- 67 positive) cells in the respective compartments of the cycle. Generally, however, when Ki-67 negative and positive subpopulations were analysed separately it was found that the former had a significantly lower (S + G2)-phase fraction than the latter. There was evidence for a correlation between Ki-67 index and (S + G2)-phase fraction at least in the subgroup of aneuploid tumours. Neither of the two parameters was correlated with stage according to Duke's classification or tumour size. However, a positive correlation was found between the fraction of unlabelled S- and G2-phase cells and tumour size as reflected in the T category.
Zölzer
F
F
Institut für Medizinische Strahlenbiologie, Universitätsklinikum Essen, Germany.
Speer
A
A
Pelzer
T
T
Streffer
C
C
D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000473:pathology*; D002453:Cell Cycle; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D019394:Ki-67 Antigen; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*
D019394:Ki-67 Antigen; D009363:Neoplasm Proteins; D009687:Nuclear Proteins