Immortalization of a @entity1 @entity2513 cell line by continuous in vitro passage: possible involvement of chromosome 1 in XXXX progression.

@entity1 @entity652 @entity296 @entity19 @entity5 @entity1412 @entity105 @entity2513 @entity694
A non-tumorigenic epithelial cell line designated PC/AA, derived from a large pre-malignant @entity2513 from a @entity1 with @entity1412 (also referred to as @entity694 ) has become immortal in vitro. PC/AA has been passaged in vitro continuously for over 4 years and shows no signs of senescence. At early passage, PC/AA has a normal diploid karyotype but with late passage is showing signs of progression, becoming @entity296 . Every cell examined of late-passage PC/AA has an isochromosome (1q), and one other marker chromosome which is probably derived from an additional chromosome 8. The majority of cells examined have 48 chromosomes. Despite showing signs of progression in vitro, late-passage PC/AA has remained non-tumorigenic in athymic @entity19 and retained morphological differentiation characteristics of colonic cells, in particular the ability to synthesize and secrete mucin. Two other cell lines derived from small @entity652 did not become immortal in vitro and were also non-tumorigenic in athymic @entity19 . The isolation of an immortal pre-malignant @entity1 epithelial cell line could prove invaluable in studies on @entity1 @entity105 and @entity5 progression. Our results, showing that only a large @entity652 and no small @entity652 have given rise to immortal cell lines, raise the possibility that the acquisition of in vitro immortality is associated with a relatively late stage in the @entity2513 sequence. The possible involvement of chromosome 1 in @entity5 progression is discussed.
