Spontaneous fusion between metastatic mammary tumor subpopulations.
This study describes a differential frequency of spontaneous fusion between metastatic and nonmetastatic subpopulations derived from a single mouse mammary tumor. Subpopulations 66, 66c14 (a variant of 66 which is resistant to both thioguanine and ouabain), 410.4, and 44FTO (a thioguanine-resistant, ouabain-resistant derivative of 410.4) spontaneously metastasize from subcutaneous and mammary fatpad sites. Subpopulations 168, 168FARO (a diaminopurine-resistant, ouabain-resistant derivative of 168), 67, 68H, and 410 do not. The ability of these subpopulation lines to fuse spontaneously in vitro was determined after coculturing a drug-resistant line with a wild-type line in nonselective media. After 16-20 h of coculture, cells were plated in the appropriate media to select for fusion products--either HAT (hypoxanthine, aminopterin, thymidine) plus ouabain or AA (alanosine, adenine) plus ouabain--to determine the number of colony-forming cells (fusion products) present per 10(4) cells plated. When both subpopulations of the pair in the fusion mixture were metastatic, a significantly greater number of fusion products was recovered than if one or both of the subpopulations in the fusion mixture was nonmetastatic, with one exception: line 410 readily fused with both 66c14 and 44FTO. Subline 410 was highly metastatic when originally isolated but lost its metastatic competence after a brief time in tissue culture.
Miller
F R
FR
E. Walter Albachten Department of Immunology, Michigan Cancer Foundation, Detroit 48201.
McInerney
D
D
Rogers
C
C
Miller
B E
BE
D000818:Animals; D002459:Cell Fusion / Q000187:drug effects; D003470:Culture Media / Q000494:pharmacology; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D008325:Mammary Neoplasms, Experimental / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009362:Neoplasm Metastasis / Q000473:pathology; D014407:Tumor Cells, Cultured
D003470:Culture Media; D004273:DNA, Neoplasm