Establishment of cell lines from B-cell precursor acute lymphoblastic leukemia.

In an attempt to establish permanent cell lines from children with B-cell precursor acute lymphoblastic leukemia (BCP-ALL), 123 clinical samples from 117 patients were cultured in vitro. Using a method which was successful for the growth of ALL with T-cell phenotype, 3% (2/74) of BCP-ALL samples from patients at diagnosis and 31% (9/29) of BCP-ALL samples from patients at relapse were established as cell lines. However, in most cultures, leukemic cells survived for only a few weeks and the majority of viable cells present after 28 days of culture were esterase-positive mononuclear cells. Based on the hypothesis that mononuclear cells inhibited leukemic cell growth, we evaluated the effect of a monocyte toxin, L-leucine methyl ester (Leu-OMe), on the growth of four frozen BCP-ALL samples. Thawed leukemic cells treated with Leu-OMe, but not untreated control cells, proliferated in three samples and one new cell line was established. Subsequently, when Leu-OMe was added to fresh leukemia cells in culture, leukemic cell lines were grown from 29% (4/14) of samples at diagnosis and 66% (4/6) of relapse samples. Overall, 20 BCP-ALL cell lines were established, all were Epstein-Barr virus (EBV)-negative, and authenticity of each cell line was verified by a direct comparison of the immunophenotype, karyotype, and genotype with the patient's tumor cells. This improved method of cell culture permits a higher success rate of cell line establishment from patients with BCP-ALL thereby aiding in analysis of B-lymphocyte transformation and neoplasia.

Characterization of a CD34+ cell line established from a child with large cell cutaneous lymphoma.

BACKGROUND: Lymphoma presenting with skin involvement has heterogeneous morphology and rarely is seen in children. To study the pathogenesis of this disease, lymphoma cells from a child with B-cell large cell lymphoma of the skin were cultured in vitro. METHODS: Lymphoma cells cultured on a feeder layer under hypoxic conditions grew in vitro after a latency period of 2 weeks. Since interleukin-6 (IL-6) induces final differentiation of activated B-lymphocytes, the cell line was evaluated for the presence of IL-6 receptors and biologic response to IL-6. RESULTS: An Epstein-Barr virus (EBV)-negative cell line (UoC-B2) was established which expressed CD34, CD45, HLA-DR, CD19, CD20, sIgM, sIgD, and lambda light chain. Good general concordance was observed between the patient's lymphoma and the cell line by comparing the immunophenotype, genotype, and karyotype. The UoC-B2 cells expressed surface IgM but did not secrete IgM into the culture media even in the presence of supplemental IL-6. CONCLUSIONS: A B-lymphoid cell line (UoC-B2) was established from a child with primary cutaneous lymphoma. The cells expressed cell surface IgM and receptors for IL-6 but supplemental IL-6 had no effect on IgM production or cell proliferation.