Heterogeneous Origin of Established Non‐T, Non‐B Cell Lines from Two Adolescent Patients with Acute Lymphoblastic Leukemia

Three leukemic cell lines were established from the bone marrow cells of two adolescents with non‐T, non‐B acute lymphoblastic leukemia (ALL) at relapse. Two cell lines from a 14‐year‐old girl and one from an 11‐year‐old boy were designated as KH‐3A, KH‐3B and KH‐4, respectively. Leukemic cells started to grow attached to the bone marrow stromal (BMS) cells. KH‐3A was positive for OKIa1 and positive at low percentages for B1, Leu‐1 and J5 antigens; KH‐3B reacted with OKIa1 and J5. Except for OKIa1, these two cell lines showed no surface marker change after 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) treatment. On TPA treatment, clones (KH‐3A‐2 and KM‐3A‐3) isolated from KH‐3A in agarose showed the induction of differentiation into T and B cell lineage. KH‐4 was positive for OKIa1 and positive at low percenteges for B1 and J5, and showed a strong reaction with OKIa1, B1 and J5 after TPA treatment. T cell receptor (TCR) β‐chain gene and immunoglobulin gene (J(H) and C(μ)) rearrangements were found in KH‐3A, KH‐3B, and sublines isolated from KH‐3 (KH‐3A‐2 and ‐3) simultaneously. These findings indicate that BMS cells are useful for the establishment of leukemic cell lines and that some common ALL (cALL) cell populations may be heterogeneous.