CELL-PROLIFERATION AND PLOIDY OF HUMAN SOLID TUMORS - METHODOLOGICAL EXPERIENCE WITH IN-VIVO BROMODEOXYURIDINE AND DNA FLOW-CYTOMETRY

A sequential procedure for single and multiparameter flow cytometry (F CM) that allows detailed cell proliferation and DNA ploidy studies of human solid tumours is reported here. This description includes time c ollection and storage, tissue disaggregation and staining as well as F CM analysis of samples. The overall feasibility, together with some cr itical aspects of the DNA/bromodeoxyuridine (BrdU) in vivo assay for c ell kinetic studies in human solid tumours, are reported, based on our experience in recent years. We found that the BrdU in vivo method, co upled with bivariate FCM for measurements, is a valuable approach for a 'dynamic' assessment of tumour cell proliferation in the clinical se tting. Routine measurements can be achieved providing that well standa rdised tissue disaggregation and immunolabelling procedures are perfor med. In different solid tumours, cytokinetic results were satisfactory in 85% of cases as far as the BrdU-labelling index is concerned while 70% were acceptable for DNA synthesis time and tumour potential doubl ing time. Causes of failure are also considered and discussed. In orde r to guarantee the finest detection of aneuploidy, routine high resolu tion single-parameter DNA analysis is suggested. Our experience with f urther improvements in cell kinetic studies based on the possibility o f gating the BrdU/DNA analysis for a subpopulation of interest (i.e. c ytokeratin-positive cells in epithelial tumours) is also reported.