Chromosome 14 marker appearance in a human B lymphoblastoid cell line of nonmalignant origin

A human B cell lymphoblastoid cell line of nonmalignant origin, derived 16 years ago, now carries a 14q+ marker chromosome in 100% of the cells analyzed. This marker was not apparent in karyotypes prepared 1 year after establishment of the line and, thus, presumably arose in culture. The cell line now grows more rapidly than typical B cell cultures and has an unusually high cloning efficiency (60%-90%). Using Southern blot hybridization, we have analyzed the arrangement of 13 onc genes that are often associated with human malignancy, including c-myc. None of these onc genes appear to be rearranged in this cell line.