title: MMC-E cells--origin and changes in karyotype accompanying malignant transformation.
abstract: Karyotype analysis of an established nontumorigenic cell line (MMC-E) indicated that the cells are of rat origin instead of mouse, as interpreted earlier. This cell line, now termed RE (rat epithelial) had a karyotype of 39,X,-5,-15,-?16,+t(3q11q) in the stem line. There was also one subline that had a karyotype of 40,X,-5,-15,-?16,+t(3q11q), +?t(5;?). Chromosome changes and frequency of sister chromatid exchanges (SCEs) were studied from seven malignantly transformed RE cell lines. These included cells transformed by Moloney murine sarcoma virus, the acute transforming retrovirus 3611-MSV, murine leukemia virus, or ethylnitrosourea. Changes in chromosomes #3 and #5 seemed to be associated with malignant transformation of RE cells. In addition to the t(3q11q) and monosomy for chromosome #5 seen in the parent cell line, monosomy for chromosome #3 and the t(5;?) were observed in all malignant cell lines. The latter changes either were absent (monosomy for chromosome #3) or present only occasionally [t(5;?)] in the parental cells. The results of SCEs showed that the malignantly transformed cell lines do not have increased frequency of SCEs as compared with that of the parental cell line.
mesh_terms: D000818:Animals; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D002472:Cell Transformation, Viral; D002871:Chromosome Banding; D004847:Epithelial Cells; D007621:Karyotyping; D051379:Mice; D051381:Rats