Differences in genetic stability between human cell lines from patients with and without lymphoreticular malignancy.

Isoenzymes determined by 11 loci have been examined in 137 human lymphoblastoid lines of various origins with a view to determining their phenotypic stability in culture. Lines of normal origin are stable and at these loci are phenotypically identical to the individuals from whom they are derived. Lymphomas and some lines from patients with leukaemias show a tendency to increased apparent homozygosity, presumably resulting from loss of expression of one or other allele during culture. Taken together with the cytogenetic evidence this suggests that progressive loss of functional parts of the genome with time in culture is a characteristic of lines derived from malignant lymphoid cells.