Differentiation by a tumor promoter of lymphoblastoid cell lines with and without Ph1 chromosome from a chronic myelogenous leukemia patient.

An attempt was made, by treatment with 12-O-tetradecanoyl-phorbol-13-acetate (TPA), to induce differentiation in Ph1-positive (PB-1049) and Ph1-negative (LN-1049) B lymphoblastoid cell lines established from a patient with chronic myelogenous leukemia, and a Ph1-positive line (PB-1049-T) derived from a tumor nodule formed by inoculation of PB-1049 cells into nude mice. The changes induced by TPA in all lines were consistent with differentiation towards plasma cells, and included enhanced clustering of floating cells, reduced DNA synthesis, increase of the cytoplasm/nucleus ratio and appearance of a large amount of rough endoplasmic reticulum in the cytoplasm. Immunoglobulin concentration was estimated by ELISA in the supernatant of the three cell lines. Remarkable increases were observed in PB-1049 and PB-1049-T cultures treated with TPA. These results suggest that the Ph1-positive as well as Ph1-negative B lymphoblastoid cell lines examined have the potential to perform the proper functions of B lymphocytes in vitro.