Cell proliferation kinetics in two human tumors grown in athymic nude mice

Abstract

Summary The technique of labelled mitoses was used to investigate the cell proliferation kinetics in two human neoplasms, one a malignant melanoma and one a fibrosarcoma, transplanted to and grown serially in the athymic nude mutant (ANM) mouse. The experimental data obtained correlated well with a theoretical percentage labelled mitoses curve based on the assumption that the time spent by a cell in each of the phases M, G₁ S and G₂ is described by four independent log-normal distributions. However, no unique second wave was defined by the experimental results. This means that only the deductions made about the duration of the G₂ and S phases are reliable. The median duration of these two phases was found to be 8 and 18 h and 8 and 16 h for the malignant melanoma and the fibrosarcoma, respectively. By comparing these results with results published on cell cycle studies of transplantable animal tumors and human tumors in situ, it is concluded that the cell cycle parameters of a human tumor grown in the ANM mouse are close to those of the same tumor in the donor patient.