title: Promotion of L1210 tumour growth by macrophages.
abstract: Low numbers (10(4)) of peritoneal exudate L1210 mouse lymphoma cells were injected into DBA/2 mice subcutaneously and the development of tumours was followed. Tumour takes occurred in 100% of the animals within 9 days after tumour transplantation. The latent period of tumour development was prolonged by 6-10 days when tumour cells of the peritoneal exudate, depleted of adherent/phagocytic cells, were used in the inoculum or when tumour cells derived from continuous cell cultures were used. Addition of adherent cells in high numbers to in-vitro-derived L1210 cells accelerated tumour growth. This effect was found to be not specific for adherent/phagocytic cells, as liver cells had the same influence on tumour growth. It is concluded that, under certain experimental conditions, a cell population with the functional properties of macrophages is able to promote tumour development, most likely due to their non-specific effect on the micro-environment of the growing tumour.
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D007939:Leukemia L1210 / Q000276:immunology*; D008264:Macrophages / Q000276:immunology* / Q000473:pathology; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA