Establishment of a new myeloid leukemia cell line (TK-1), and isolation of cells having a translocation involving a band 17q23.

A myeloid leukemia cell line (TK-1) was established from the peripheral blood of a patient with lymphoblastic lymphoma whose leukemia cells were composed of T-lymphoblasts and immature myeloid cells. The established TK-1 cell line consisted of immature myeloid cells with heavy azurophilic granulation in the cytoplasm. The TK-1 cells were positive for peroxidase, and exhibited a strong positive reaction for alpha-naphthyl acetate esterase and naphthol AS-D chloroacetate esterase. The cells were weakly positive for Fc gamma-receptors, showed no phagocytosis and did not reduce NBT. With the treatment of 1 alpha, 25-dihydroxy-vitamin D3, they exhibited morphological and functional differentiation. The TK-1 cell line contained normal diploid cells and pseudodiploid cells, and the two populations were successfully cloned; the clone with a normal karyotype was designated the TK-1D cell line, and the clone with a pseudodiploid karyotype, which had a translocation involving chromosomes 14, 17 and one other chromosome, was designated the TK-1B cell line. These cloned cells lacked Epstein-Barr virus nuclear antigens and had almost the same myelomonocytic characteristics as the parent TK-1 cells. The breakpoint of chromosome 17 involved in the translocation of the pseudodiploid cells was identified to be a band 17q23.