Possible involvement of chromosome 1 in in vitro immortalization: evidence from progression of a human adenoma-derived cell line in vitro.
We have previously reported that continuous in vitro passage in the presence of 3T3 feeders of a non-tumorigenic adenoma-derived epithelial cell line, designated PC/AA, resulted in its becoming immortal. At early passage PC/AA was normal diploid, whereas every cell of PC/AA late passage had an isochromosome 1(q) which led us to suggest that abnormalities of chromosome 1 may be involved in tumour progression. We now report the isolation of a 3T3-feeder-independent variant of early-passage PC/AA, designated PC/AA/FI, which was immortal in vitro and remained non-tumorigenic. Each cell of PC/AA/FI again has an isochromosome 1(q), like the late-passage PC/AA. However, with PC/AA/FI it is the other chromosome 1 of the homologous pair which is involved in the formation of the isochromosome 1(q). This is possible to determine because of the polymorphic centromeric heterochromatin on chromosome 1 of the early-passage PC/AA. With the late-passage PC/AA (grown with 3T3 feeders) the homologue with the large C-band has given rise to an isochromosome 1(q) whereas with PC/AA/FI it is the other homologue with the smaller C-band which has given rise to this isochromosome. Both the immortal PC/AA/FI and the immortal PC/AA late passage, therefore, have independent abnormalities involving chromosome 1. These results indicate that chromosome 1 may be involved in in vitro immortalization.
Paraskeva
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Department of Pathology, University of Bristol Medical School, UK.
Harvey
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A
Finerty
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Powell
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D000236:Adenoma / Q000235:genetics* / Q000648:ultrastructure; D011125:Adenomatous Polyposis Coli / Q000235:genetics* / Q000473:pathology; D000818:Animals; D002460:Cell Line; D002869:Chromosome Aberrations / Q000235:genetics / Q000473:pathology; D025063:Chromosome Disorders; D002878:Chromosomes, Human, Pair 1; D002999:Clone Cells / Q000648:ultrastructure; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000648:ultrastructure; D006801:Humans; D007621:Karyotyping; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D014407:Tumor Cells, Cultured