The relation between cell proliferation and the vascular system in a transplanted mouse mammary tumour

Abstract

A mouse mammary tumour in which viable tissue was arranged cylindrically about tumour blood vessels is described, and the techniques of thymidine autoradiography have been used to investigate parameters of cellular proliferation within these tumour cords. Both labelling and mitotic index were found to decrease with increasing distance from the axial blood vessel. Labelled mitoses and repeated labelling results suggested a decrease in the growth fraction. The median cell cycle time, however, showed little variation in the tumour cords. The diffusion of metabolites was discussed in the light of other published data and the cord structure was found to be consistent with a theory of limited oxygen diffusion. This hypothesis was tested by investigating tumour growth in animals maintained under conditions of hyperbaric oxygen and of hypoxia. Hypoxic conditions caused a reduction in both the mean tumour cord radius and in the labelling index. I should like to thank both Professor L. F. Lamerton and Dr. G. G. Steel for their constant encouragement and useful discussion. Miss J. Lambert provided valuable technical assistance throughout the project, and I should like to record my thanks to her, and the many other members of the Department who advised or assisted at various times. © 1968, The British Empire Cancer Campaign for Research. All rights reserved.