Does in vitro colony formation and chemosensitivity relate to DNA ploidy and S-phase fractions?

Abstract

In vitro colony formation and chemosensitivity were analyzed in 65 human solid tumors and compared to proliferation parameters simultaneously obtained by DNA flow cytometry of the same tumor specimens. Colony growth in the human tumor colony assay was enhanced in aneuploid tumors (39/65) in comparison to diploid tumors (26/65, P less than 0.05). In addition, there was a relationship between % S-phase and colony growth. The existence of polyploid sublines (23/65) improved in vitro growth even in tumors with a diploid main G0/1-peak or with a low % S-phase. Metastases exhibited a higher proportion of aneuploidy and showed slightly better growth in vitro than primary tumors. Sensitivity testing in 34 of the 65 tumors showed no convincing relation between DNA parameters and the inhibition of colony formation by five standard anticancer agents with different mechanisms of action. This indicates additional factors other than the proliferative activity of the tumor to be responsible for drug sensitivity or resistance.

Relationship between changes in ploidy and stable cellular resistance to hydrogen peroxide

“…Results are equivocal concerning the clinical implications and prognostic values of the differences in ploidy. Some authors have found that ploidy differences correlate with increased aggressiveness of the disease and poorer prognosis following treatment (Volm et al, 1985;Preisler et al, 1983), but others have not (Masters et al, 1987;Flentje et al, 1987). In the present investigation, we explored the relationship between changes in ploidy and HzOz resistance.…”