Growth of normal and tumour haemopoietic cells on glass coverslips in peritoneal cavity of mice. I. Characterization of colonies.

A method for cultivation of normal and tumour haemopoietic progenitor cells on glass coverslips inserted into the peritoneal cavity of mice is described. This technique is a modification of the method proposed by Seki (1973). Intraperitoneal injections of bone marrow cells into syngeneic mice led to the formation of erythroid, myeloid, megakaryocytic, mixed and non-identified colonies on the GC. The greatest number of erythroid colonies was seen on the 3rd-5th day after bone marrow cell injection. The majority (greater than 90%) of the erythroid colonies consisted of 16-80 benzidine-positive cells. When GC-bearing mice were rendered anaemic, the number of erythroid colonies sharply rose, whereas the number of myeloid colonies remained unaltered. The influence of irradiation on haemopoietic colony formation was also investigated. There was a linear relationship between the dose of bone marrow cells injected and the number of haemopoietic colonies formed. Areas of mono- and multilayer growth were observed on the GC. Haemopoietic colonies always occurred on a cell multilayer containing fibroblast-like cells and were never observed on a cell monolayer consisting of macrophage-like cells. When self-maintaining erythroleukaemic cells transformed by Rauscher leukaemia virus (RAL cell line) were cloned, GC tumour colonies formed not only on a multilayer but also on a monolayer. Erythroleukaemic K-2 cells, which were of the same origin as RAL cells and had undergone 500 passages in vitro, did not form colonies on the GC. The nature of haemopoietic progenitor cells (mainly erythroid) forming colonies on GC, the nature of cells providing the haemopoietic inductive microenvironment on GC, the direction of tumour progression in RAL and K-2 cells, as well as some possible applications of the GC colony assay are discussed.