Identification of non-proliferating cells in melanoma B16 tumour

Abstract

THE detection of growth fraction and the characterisation of non-proliferating cells are extremely important in human tumour therapy^1,2. Cytological criteria for individual objective discrimination in vivo between non-proliferating and proliferating cells with the same DNA content have not been previously available³. It has been shown recently, in vitro, that the transition from the non-proliferating to proliferating state (G0—G1) of WI-38 cells—human diploid fibroblasts—can be objectively characterised in the intact cell by flow microfluiorimetry⁴ and geometric–densitometric texture analysis⁵. Similar differences in nuclear morphometry and chromatin conformation between proliferating G1 and non-proliferating ‘G0 + Q’ cells are reported here for the first time for tumour cells in vivo, by parallel utilisation of objective image analysis and multiparameter laser flow microfluorimetry, both correlated with autoradiography.