Heterotransplantation and clonal growth of human Ph'-chromosome-positive leukemia-cell (NALM-1) and B-cell leukemia-cell (BALM-2) lines.

Human hematopoietic cell lines, NALM-1, derived from Ph'-chromosome-positive chronic myelocytic leukemia (CML) in blastic crisis, and BALM-2, derived from B-cell acute lymphoblastic leukemia (ALL), were tested for their heterotransplantability and clonability. Two previously established cell lines, a Burkitt's lymphoma cell line, B35M, and a B-lymphoblastoid cell line, B411-4, derived from a hematologically normal person, were used for comparison. Ten million cells were needed in order for the BALM-2 cell line to grow with 74% success in the immunosuppressed mice, but 1000 million cells were needed in order for the NALM-1 cell line to grow with 74% success in those mice. As in the case of the BALM-2 line, 10 million cells of the B35M cell line were needed for 100% success in heterotransplantation, whereas 30 million cells of the B411-4 cell line resulted in 20% success of heterotransplantation. In a semisolid agarose (0.15%) medium, the cloning efficiencies of BALM-2, B35M, and B411-4 were 1.52--2.08, 26.31--38.46, and 0.09--0.12, respectively. With as many as 25,000 cells per well plated, NALM-1 did not produce any colonies in the semisolid agarose medium. Unlike most previous findings, those of the present study suggest that the heterotransplantability and clonability of cultured cells may not be invariably reliable characteristics of all proven human leukemia-lymphoma cell lines. The behavior of these leukemia cell lines representing their respective original leukemia clones is interpreted as reflecting the heterogeneity inherent in the biologic characteristics seen in human leukemias.