Studies on rat mammary adenocarcinomas: a model for metastasis

Abstract

Studies carried out by the authors on the rat mammary adenocarcinoma cell lines MAT 13762 and DMBA-8 are summarized. A series of variants and somatic cell hybrids have been prepared and partially characterized in terms of phenotypic properties which may correlate with metastatic potential. These include measurement of in vitro migration, lectin binding properties, expression of procoagulant activity and shedding of cell surface components. Particular emphasis has been placed on the production of enzymically-active plasminogen activator, as this seems to correlate with the ability of cells to metastasize. The finding has also been made that several of the cell types studied produce, in vitro, an inhibitor of plasminogen activator which may influence the metastatic behaviour of tumor cells. Results obtained are discussed in the context of the usefulness of these tumor systems for the study of spontaneous and experimental metastasis and the factors involved in these processes. Preliminary results of cloning and fluctuation analysis of metastatic potential together with discussion of the role of the metastatic heterogeneity and the formation of metastatic variants by mutation events are included.

Immunostimulating cell surface substance from Staphylococcus epidermidis strain ATCC-31432 prevents metastatic lung colonization in Balb/c-mice

“…In addition it may facilitate the aggregation of cancer and blood ceils (usually platelets) which promote the arrest of these aggregates in capillaries and induce the initial phase of their adhesion to the capillary endothelium [6]. Recent studies demonstrated strong positive correlations between PCA and lung tumor colonization [12,20]. Accordingly, inactivation of PCA by heparin proved to be an excellent adjuvant to immunostimulating therapy [5].…”

“…Human leucocyte preparation and activation as well as measurement of humoral IgM response (direct plaque forming method) were carried out as previously described [20].…”

Expression of the nm23-2/NDP kinase α gene in rat mammary and oral carcinoma cells of varying metastatic potential

“…Rat mammary carcinoma cell lines The derivation and characteristics of cell lines derived from the chemically-induced rat mammary adenocarcinomas DMBA-8 and MAT 13762, have previously been described in some detail (Ramshaw & Badenoch-Jones, 1985;Ramshaw et al, 1986). The original parent cell line adapted from the DMBA-8 tumour , is capable of forming tumours but does not metastasise in syngeneic Fischer 344 rats (Ramshaw & Badenoch-Jones, 1985).…”

“…A minimal in vivo selection of DMBA-8-derived clones, resulted in cell lines which were completely non-metastatic (NM4) or highly metastatic (metastatic ascites, MA; metastatic clone 2, MC2) when injected sub-cutaneously or via tail vein into host animals (originally described in Ramshaw & Badenoch-Jones, 1985;Ramshaw et al, 1986;Dear et al, 1989). The MAT 13762 parent cell line, by contrast, was itself highly metastatic in syngeneic Fischer 344 rats (originally described in Ramshaw & Badenoch-Jones, 1985). A MAT 13762 6-thioguanine-resistant variant (J-clone), however, maintained some tumour-forming potential but was found to be consistently incapable of metastasising in syngeneic host rats (Ramshaw et al, 1982).…”

“…The original parent cell line adapted from the DMBA-8 tumour , is capable of forming tumours but does not metastasise in syngeneic Fischer 344 rats (Ramshaw & Badenoch-Jones, 1985). A minimal in vivo selection of DMBA-8-derived clones, resulted in cell lines which were completely non-metastatic (NM4) or highly metastatic (metastatic ascites, MA; metastatic clone 2, MC2) when injected sub-cutaneously or via tail vein into host animals (originally described in Ramshaw & Badenoch-Jones, 1985;Ramshaw et al, 1986;Dear et al, 1989). The MAT 13762 parent cell line, by contrast, was itself highly metastatic in syngeneic Fischer 344 rats (originally described in Ramshaw & Badenoch-Jones, 1985).…”