SKY and genetic fingerprinting reveal a cross-contamination of the putative normal colon epithelial cell line NCOL-1

In vitro studies addressing the primary prevention of colon carcinoma are preferably conducted using normal colonic cells, because these cells are more likely to represent the potential target for prevention in vivo. Established cell lines of normal colonic origin are mostly lacking; however, this is probably due to the difficulties associated with establishment of such cell lines. Cross-contamination with malignant cells is a frequent event, and so any successfully established cell line of normal origin should be scrutinized prior to further investigation. We performed a cytogenetic (spectral karyotyping) and genetic fingerprint (Promega PowerPlex ES multiplex system and Applied Biosystems AmpFlSTR SGM Plus multiplex system) analysis of the putative normal colon epithelial cell line NCOL-1, derived from two different sources (NCOL-1a and 1b). We show that NCOL-1a and 1b are probably derived from the colon carcinoma cell line LoVo, with a matching probability of 99.9995, most probably through cross-contamination. Karyotypes of LoVo and NCOL-1a were identical; NCOL-1b displayed additional marker chromosomes. Our findings highlight the importance of molecular and cytogenetic characterization of established cell lines to avoid drawing misleading conclusions from the original findings.