The importance of a molecular cytogenetic analysis before using cell lines in research : the case of the KG-1a leukemia cell line

摘要

The KG-1 and its less differentiated subline KG-1a are leukemia cell lines used in research in many laboratories. The karyotypes of the two lines were initially identical. Over the years, further analysis revealed that they had acquired additional karyotypical abnormalities and that differed for the presence of some typical chromosomal rearrangements. To obtain a cytogenetic authentication before the use these two cell lines, we analysed their karyotype combining DAPI- and CMA-chromosome bandings, and a FISH-based approach by using BAC clones useful for the identification of chromosome regions of interest. Particularly, sequences of the genes MYC, PLZF, RARA and BCR that are known to play a critical role in leukemogenesis, and some BAC clones mapped to five known common fragile sites were used for the FISH analysis. Moreover, we used a telomeric probe (TTAGGG)n, and a set of BAC clones to characterize the marker chromosome der(1) that we observed in the cell line KG-1a. The existence of notably differences between the karyotype of the KG-1a cell line previously described and that described by us demonstrate as it would be advisable that the utilization of established cancer cell lines is preceded by a cytogenetic and/or molecular characterization.