Longitudinal karyotype and genetic signature analysis of cultured human colon adenocarcinoma cell lines LS180 and LS174T.

Giemsa-banded chromosomes were analyzed at intervals during either 34 or 70 serial subcultivations of two cell lines, LS180 and LS174T, established from one primary human colon adenocarcinoma, and at passage 14 of autochthonous normal bowel cells, NB(LS174T). The cell lines were established and subcultured by either scraping or trypsin treatment of primary cultures; the scraped cell line was designated LS180, and the trypsin-dispersed cell line was named LS174T. Early passages of LS174T cells were composed mainly of 46,XX (38%) and 45,X (34%) karyotypes; LS180 cultures possessed cells with 46,XX (54%), 45,X (7.5%), and 47,XX+D (19.5%) chromosome modes. In both cell lines, the 45,X karyotype predominated in later subcultivations. After the fifth passage, all LS180 cells examined exhibited a translocation from the long arm of the X chromosome to the long arm of the No. 5 chromosome. Cultures from the patient's normal bowel mucosa and peripheral blood leukocytes had normal 46,XX karyotypes. Genetic signature analysis sustantiated the common genetic origin of the cell lines, and we concluded that differences observed between LS180 and LS174T were not due to contamination with other cell lines. LS180 and LS174T represent closely related cell lines differing cytogenetically in a translocation.