Abstract
Jurkat cell line is one of the most commonly used T lymphoblast cell models; however, their stability during in vitro culture is of particular concern. Previous work has suggested that chromosomal instability (CIN) is one of the primary issues with cell lines, which involves perpetual gain or loss of whole or partial chromosomes during mitosis and results in genetic heterogeneity within a cell population. Despite frequent discussion of the genomic and phenotypic stability of cancer cell lines in literature, no solid study has been done to characterize Jurkat’s CIN status during consecutive passages. Thus, this project aimed to use multiplex fluorescent in situ hybridization (M-FISH) to assess karyotypic alterations in the Jurkat cells during their in vitro culture and to investigate the potential implications of the resulting chromosomal aberrations.
The Jurkat cell line was maintained over 60 culture passages. Cellular morphology was monitored regularly throughout the culture. Cell harvesting and M-FISH were performed at passage 0, passage 40 and passage 60. Ten metaphases were analyzed for each passage group, and chromosomal constitutions were compared to gain information on cell-to-cell variability and karyotypic progression. The prevailing karyotype in our original Jurkat sample was 45,X,- Y,del(2)(p23), which slightly differed from the ATCC reported karyotype 46,XY,del(2)(p21p23),del(18)(p11.2). The proportion of cells containing this modal karyotype decreased from 80% at passage 0, to 60% at passage 40 and 30% at passage 60. More non- clonal chromosomal aberrations were identified with increasing passage numbers, most of which are implicated in leukemogenesis and other mechanisms that might affect the behaviour of Jurkat cells. Morphology observations over 60 passages showed no profound differences in cell size and shape.
Overall, the Jurkat cell line demonstrated an increasing trend in the level of CIN, directly proportional to the length of time the cells were in culture. This finding is important because underlying CIN in cell lines, if uncontrolled, may result in false or irreproducible experimental data. It should become the consensus of the scientific community that prolonged culturing and passaging of cell lines should be avoided to minimize the effects of CIN.