title: The observation of some biological characteristics of transformed cells induced by MNNG in vitro.
abstract: The early passage diploid Syrian hamster embryo (SHE) cells were treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The treated cells proliferated rapidly; the doubling times shortened; colonies appeared in solid agar medium and transformed foci formed in tissue culture. All of these phenomena suggest that malignant transformation of SHE cell has occurred. Faster cell division rate and multipolar mitosis were demonstrated by time-lapse cinemicrography and scanning electron microscopy. Multipolar mitosis can occur in two forms: direct division and indirect division. The transformed cells were more abundant in microvilli, the number of which increased in accordance with the degree of malignancy. In comparison with the controls, the transformed cells expressed a greater tritiated thymidine incorporation, greater DNA contents and more chromosomes, but no difference in nuclear area. The determination of amino acid changes in media due to the growth of transformed cells showed that the decrease in arginine and increase in ornithine are significant. The results of allogenic animal inoculation suggest that the transformed cells can be characterized into several different stages in the process of transformation.
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000187:drug effects* / Q000473:pathology / Q000648:ultrastructure; D002869:Chromosome Aberrations / Q000187:drug effects; D003208:Concanavalin A / Q000494:pharmacology; D006224:Cricetinae; D000242:Cyclic AMP / Q000032:analysis; D004273:DNA, Neoplasm / Q000032:analysis; D004622:Embryo, Mammalian; D008647:Mesocricetus; D008769:Methylnitronitrosoguanidine / Q000633:toxicity*; D008855:Microscopy, Electron, Scanning; D009368:Neoplasm Transplantation
chemical_list: D004273:DNA, Neoplasm; D003208:Concanavalin A; D008769:Methylnitronitrosoguanidine; D000242:Cyclic AMP