Establishment of a Ph1-positive human cell line (BV173)

A new cell line (BV173) derived from a patient with Philadelphia chromosome (Ph1)-positive acute leukemia was compared with the Ph1-positive K562 and NALM-1 lines, which display the phenotypic characteristics of erythroid and pre-B cells, respectively. BV173 cells retained the Ph1 chromosome and had the morphologic and cytochemical features of undifferentiated blast cells. They lacked the membrane characteristics of mature B- or T-lymphocytes and did not react with monoclonal antibodies to the myelomonocytic cell lineage. Although they reacted with anti-glycophorin A antiserum, they failed to produce hemoglobin after butyric acid treatment. This line was similar to NALM-1 in that it bore common acute lymphoblastic leukemia antigen and la-like antigen, reacted with monoclonal antibodies directed against early stages of hematopoietic cell differentiation, and presented the nuclear enzyme terminal deoxynucleotidyl transferase. However, it differed from NALM-1 because it did not express cytoplasmic IgM, a marker of pre-B-cells. The new line can be considered a clonal expansion of leukemia cells blocked at an earlier differentiation stage than that for the other Ph1-positive cell lines.