Growth kinetics of human lung tumours in nude mice.

In order to investigate the growth characteristics of xenografts of human tumours in nude mice, we heterotransplanted 22 human tumours of the lung into nude mice. We noted growth in 11 of these tumours (50%). The histological appearance of most of the tumours growing in the first passage in nude mice was comparable with that of the donor tumours. In further passages, however, a progressive dedifferentiation was noted in many tumours, depending on their growth rate. With the aid of growth curves and cell cycle kinetics (FMF analysis) it is shown that the growth kinetics of these tumours is affected by the transplantation and that the growth rate of such xenografts in nude mie is different from that of the original tumour in the patient.