Non-random karyotypic changes in Djungarian hamster tumors induced by 3-methylcholanthrene.

The karyotypes of 30 tumors (sarcomas and adenocarcinomas) induced with methylcholanthrene in Djungarian hamsters (Phodopus sungorus campbelli) have been investigated. In 23 tumors structural changes of the short arm of X-chromosome (Xp+ or Xp = type) were revealed. Non-random rearrangements of 3p, 7q and 8q were also observed. Other structural or numerical changes of the karyotype were accidential. For majority of tumors the presence of chromosome markers with long homogeneously staining regions or double minutes, structures are known as cytological manifestation of gene amplification, was typical. Induced tumors of the Djungarian hamster might serve as an interesting tool for studies of relationship of somatic cell genetic changes to different aspects of chemical carcinogenesis.