title: Identification of murine endogenous xenotropic retrovirus in cultured multicellular tumour spheroids from nude-mouse-passaged nasopharyngeal carcinoma.
abstract: After nude-mouse-passage, a carcinoma of the nasopharynx was found to contain a few scattered C-type retrovirus particles. Culture of this nude-mouse-grown material over solid agar allowed the human tumour cells to grow as multicellular spheroids which increased in number by budding and could be subcultured for up to 6 months. Within the spheroids the human tumour cells expressed increased retrovirus replication and large numbers of C-type particles were observed. Treatment with a halogenated pyrimidine further enhanced the virus production. This tissue culture system provided sufficient virus production for the identification of the retrovirus as an endogenous xenotropic murine leukaemia virus and not a human agent.
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002460:Cell Line; D002478:Cells, Cultured; D003470:Culture Media; D004279:DNA, Viral; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D005260:Female; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000382:microbiology* / Q000648:ultrastructure; D012190:Retroviridae / Q000648:ultrastructure; D013997:Time Factors; D014762:Viral Interference; D014779:Virus Replication
chemical_list: D003470:Culture Media; D004279:DNA, Viral; D012321:DNA-Directed RNA Polymerases; D001973:Bromodeoxyuridine