Effect of tumour-associated macrophages on the growth of tumours in rats.
Tumours that had grown in syngeneic rats were depleted of macrophages in vitro. A comparison was made with non-depleted tumours of their growth in the feet and spread to the popliteal lymph nodes in untreated, irradiated (500 rads) or carrageenan-treated rats. A non-metastasizing methylcholanthrene-induced fibrosarcoma (D8) grew better in the feet of all three groups after macrophage depletion but metastasized more extensively only in irradiated rats; irradiation increased the growth of non-depleted D8 in the feet. D8M, a metastatic variant of D8, grew less extensively in the feet of normal rats after macrophage depletion. Its metastatic spread was increased by macrophage depletion in carrageenan-treated rats only. Non-depleted D8M grew less well in the feet or irradiated or carrageenan-treated rats than in normal rats. A metastasizing spontaneous adenocarcinoma (ST-2) grew less well in normal rats after macrophage depletion. The non-depleted tumour grew less well in irradiated rats but macrophage depletion had no further effect. Metastasis of ST-2 to the popliteal node of normal rats was abolished by macrophage depletion. The nature of the host macrophage-tumour relationship seems to differ from tumour to tumour.
D000230:Adenocarcinoma / Q000276:immunology; D000818:Animals; D002351:Carrageenan / Q000494:pharmacology; D002471:Cell Transformation, Neoplastic / Q000528:radiation effects; D005121:Extremities; D005354:Fibrosarcoma / Q000276:immunology; D008198:Lymph Nodes / Q000473:pathology; D008264:Macrophages / Q000276:immunology*; D009362:Neoplasm Metastasis / Q000276:immunology; D009374:Neoplasms, Experimental / Q000276:immunology*; D051381:Rats
D002351:Carrageenan