Genetic analysis of tumorigenesis: VI. Chromosome rearrangements in tumors derived from diploid premalignant Chinese hamster cells in nude mice.
The chromosome constitution of CHEF/16 clones recovered from methylcellulose and of uncloned, tumor-derived CHEF/16 populations are compared. Nine of 11 clones recovered from methycellulose were initiated by diploid cells. Moreover, chromosomally diploid cells were still present in most CHEF/16 clones even after growth in anchorage-independent conditions. In contrast, none of the CHEF/16 cells recovered from tumors were diploid. Nonrandom chromosome changes were observed, but no specific chromosome alterations were consistently found in tumor-derived CHEF cells. Although CHEF/16 cells are uniformly tumorigenic in nude mice, each of 10 uncloned tumor-derived populations from inocula of 10(2), 10(4), and 10(6) CHEF/16 cells consisted of only 1-3 stemlines. Our results show that diploid CHEF/16 cells are premalignant and undergo karyotypic changes leading to successful and usually clonal establishment of tumors in nude mice.
D000818:Animals; D002471:Cell Transformation, Neoplastic; D002869:Chromosome Aberrations; D002999:Clone Cells; D006224:Cricetinae; D003412:Cricetulus; D003470:Culture Media; D004622:Embryo, Mammalian; D005347:Fibroblasts; D007621:Karyotyping; D008747:Methylcellulose; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000235:genetics*
D003470:Culture Media; D008747:Methylcellulose