Density/volume analysis in the study of cellular heterogeneity in human ovarian carcinoma

Abstract

Summary.-A method is presented for the description of a heterogeneous cell population with respect to the volume and density of its cellular components, based on computer analysis of the cell-volume spectra of density-gradient fractions. Display programmes were developed to produce either a perspective plot or an isofrequency contour plot ("fingerprint") of the two-parameter data. The use of sequential density and velocity gradients permitted the separation and study of the properties of any subpopulation.We describe the results of an analysis of cellular heterogeneity in an ovarian carcinoma cell line and in 2 cases of ascites cells from human ovarian carcinoma The proliferative state (labelling index) and growth potential (culture clonogenicity) of cells from one malignant ascites have been "mapped" in terms of density/volume parameters. The results are discussed in terms of their impact on the view of human ovarian carcinoma as a stem-cell system.

Replating efficiency of metastatic melanoma cells from lymph node and subcutaneous sites does not predict patient survival

“…The self-renewal properties of cells from ovarian and bladder cancers were measured and n=4-6 was calculated [11,12,14], but no relationship of PE 1 or PE 2 to clinical parameters has yet been published. The self-renewal properties of cells from ovarian and bladder cancers were measured and n=4-6 was calculated [11,12,14], but no relationship of PE 1 or PE 2 to clinical parameters has yet been published.…”

Clonogenic tumour cells

“…Both of these examples relate to established tissue culture lines where the starting cell populations presumably are homogeneous. Mackillop et al (1983) have indicated how much more serious this problem is in cloning studies on human tumour cells. Even untreated cells produce a range of colony sizes in soft agar and often it is difficult to find objective criteria for distinguishing viable from nonviable colonies.…”

“…Evidence for a hierarchical structure among tumour cells that might lead to heterogeneity among clonogenic cells is at present mainly circumstantial, arising from the evidence for this in normal tissues from which tumours have come (Potten, 1983). Mackillop et al (1983) have formalised this idea. Clonal heterogeneity, the idea that various clonal sublines may coexist within a tumour, is a subject of considerable current interest.…”

“…The use of cell cloning assays to describe cellular heterogeneity, self-renewal capacity, and possible hierarchical differentiation in ovarian cancer (Buick and Mackillop, 1981;Mackillop et al, 1982) is of great interest and no doubt will be described elsewhere in this volume. Cell sorting techniques are being used to search for high-cloning subpopulations within human tumours (Hoshino et al, 1982) and there is evidence for the existence of clonal subpopulations that differ in therapeutic sensitivity (Leith et al, 1982).…”

The estimation of self-renewal in the clonogenic cells of human solid tumours: A comparison of secondary plating efficiency and colony size

“…The number of cells contained in the larger colony was calculated by dividing the volume of the colony by the mean volume of the individual cells. Cell volumes were measured using a Coulter counter linked to a pulse height analyzer in a custom built system as described previously (Mackillop et al, 1982) and validated by measuring the mean radius of 50 tumour cells in suspension, using the scaled ocular. When every proliferative unit within a low power field had been assigned a size and counted, another field was chosen at random and the process was repeated until at least 2000 cells or groups of cells had been scored.…”