title: Evidence for suppression of cellular growth in vitro and selection against the indigenous mouse X chromosome in A9 cell hybrids after microcell-mediated transfer of an X from other mammalian species.
abstract: Introduction of a human or Syrian hamster X chromosome (derived from BHK-191-5C cell hybrids) into tumorigenic mouse A9 cells via microcell fusion induced changes in cellular morphology and a retardation of cellular growth. The suppression of growth of the hybrids could be abolished, however, by daily changes of medium containing 20% serum. G-banding analysis showed the absence of a single, cytogenetically identifiable, indigenous X chromosome (marker Z) in two of four hybrid clones after an X chromosome was transferred from either hamster or human cells. All hybrids were tumorigenic when tested in nude mice. Together, these data suggest that the loss of the mouse X chromosome took place probably because of growth inhibitory effects imposed on hybrid cells due to the increase in X chromosome dosage. In addition, our results show a lack of association between the phenotype of cellular growth suppression in vitro and the phenotype of suppression of tumorigenicity in vivo.
authors.affiliation: Laboratory of Cancer Genetics, Division of Cell Biology, Department of Biomedicine and Surgery, Faculty of Health Sciences, Linköping University, Sweden. quais@mcb.liu.se
authors.forename: M Q
authors.initials: MQ
authors.lastname: Islam
authors.forename: K
authors.initials: K
authors.lastname: Islam
mesh_terms: D000818:Animals; D002455:Cell Division / Q000235:genetics; D002459:Cell Fusion; D048429:Cell Size / Q000235:genetics; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000473:pathology; D002871:Chromosome Banding; D002999:Clone Cells / Q000166:cytology / Q000378:metabolism / Q000473:pathology / Q000637:transplantation; D006224:Cricetinae; D018628:Gene Dosage; D018014:Gene Transfer Techniques; D016147:Genes, Tumor Suppressor / Q000235:genetics*; D005819:Genetic Markers / Q000235:genetics; D006801:Humans; D006822:Hybrid Cells / Q000166:cytology / Q000378:metabolism* / Q000473:pathology* / Q000637:transplantation; D007621:Karyotyping; D008647:Mesocricetus; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000235:genetics / Q000473:pathology; D010641:Phenotype; D014960:X Chromosome / Q000235:genetics*
chemical_list: D005819:Genetic Markers