Continuous leukemia-lymphoma cell lines are important research tools, in particular as starting material for the cloning of recurrent translocations. In 1998, we established the continuous leukemia cell line MUTZ-5 and its two simultaneous sister cell lines MUTZ-6 and MUTZ-7. The primary specimen was obtained from the peripheral blood of a 26-year-old man with B cell precursor acute lymphoblastic leukemia at relapse carrying a t(12;13). The immunoprofile of MUTZ-5 corresponds to that of a precursor B cell. The immunoglobulin heavy chain gene was found to be rearranged. Despite receptor expression, none of the cytokines examined enhanced proliferation; several cytokines had significant inhibitory effects. Giemsa-banding cytogenetics showed the following karyotype which was identical in all three sister cell lines: 45<2n>X, -Y, t(12;13)(p12;q13-14). The karyotype and DNA fingerprinting confirmed the malignant nature and the authenticity of the cell line, excluding cross-contamination with other cells. MUTZ-5 represents a new unique leukemia B cell line; its scientific significance lies in the t(12;13).
Adult B-Lymphocytes