Establishment of two Ph1 chromosome-positive cell lines, KPB-M8 and KPB-M15

Two new Philadelphia (Ph1) chromosome-positive cell lines, designated KPB-M8 and KPB-M15, were established from the peripheral blood of two patients with chronic myelogenous leukemia in blastic crisis. Both cell lines were characterized by blastic appearance, the presence of acid phosphatase activity, Fc gamma-receptor, and C3-receptor, and reactivity to monoclonal antibodies such as OKM1, MCS2, MY906, MY4 and MY7. These results indicate that KPB-M8 and KPB-M15 cells are of an undifferentiated blast nature. Both cells retained Ph1 chromosome, and showed numerical and structural changes upon chromosomal analysis. These cell lines should provide a useful source for studying differentiation of hemopoietic cells.