Phenotypic changes associated with chemically induced differentiation of a hairy cell leukemia cell line

In vitro chemically induced differentiation of the JOK-1 cell line, derived from a patient with hairy cell leukemia, has been studied. Non-induced JOK-1 cells expressed sIgM, B-1, CALLA, Ia, and C3 receptors. Following exposure to 2% DMSO, or 100 ng/ml 12-O-tetradecanoyl-phorbol-13-acetate (TPA), the cells underwent a phenotypic change from lymphoblastoid to monocytoid. In the presence of TPA, they became adherent and developed dendritic processes. Associated with these changes was a decrease in sIgM and CALLA and variable expression of C3 receptors. No monocyte/macrophage-associated antigens were detected. These results suggest that the JOK-1 cell line may have a limited ability to differentiate but is not mature enough to complete the differentiation process.