Establishment and characterization of IRTA17 and IRTA21, two novel acute non-lymphocytic leukaemia cell lines with t(16;21) translocation

Establishment and characterization of a novel acute myeloid leukemia cell line, JIH-4, carrying a t(16;21)(p11.2;q22) and expressing the FUS-ERG fusion

Human leukemia cell lines are powerful tools in the study of leukemogenesis, particularly for rare but recurrent subtypes such as acute myeloid leukemia (AML) with the t(16;21)(p11.2;q22) and FUS-ERG fusion. Four AML cell lines carrying a t(16;21)(p11.2;q22) have been described previously. We report a novel AML cell line, designated JIH-4, for which karyotypic analysis demonstrated a single abnormality, t(16;21)(p11.2;q22). The FUS-ERG fusion transcript was identified by reverse transcriptase polymerase chain reaction (RT-PCR). Neither Epstein-Barr virus nor mycoplasma was detected in JIH-4 cells. The morphology and immunoprofile of JIH-4 cells display typical features of myelogenous lineage, and short tandem-repeat PCR comparison with the donor patient's bone marrow cells confirm the cell line's authenticity. Tumor masses were found in 50% of inoculated mice 83 days after subcutaneous injection with JIH-4 cells. Our results confirm that JIH-4 cells are derived from the donor patient's leukemia cells and support using the JIH-4 cell line as a valuable tool in the study of leukemogenesis.

Myeloid differentiation antigen and cytokine receptor expression on acute myelocytic leukaemia cells with t(16;21)(p11;q22): frequent expression of CD56 and interleukin-2 receptor alpha chain

We report the cellular characteristics of cells from three patients with de novo acute myelocytic leukaemia (AML) with t(16;21)(p11;q22), two M4 and one M5a according to the FAB classification, and two permanent cell lines with t(16;21)(p11;q22), TSU1621MT and YNH-1. The FUS/ERG fusion mRNA was demonstrated in all cases by reverse transcriptase-polymerase chain reaction (RT-PCR). The immunophenotypes of the AML cells, and YNH-1 and TSU1621MT cell lines with t(16;21) were characterized as CD34+CD33+CD13+CD11b+CD18+CD56+ HLA-DR-/+. Cells from all samples strongly expressed c-kit, granulocyte colony-stimulating factor receptor (G-CSFR), c-fms (macrophage colony-stimulating factor receptor), interleukin-3 receptor alpha chain (IL-3Ralpha), and granulocyte macrophage colony-stimulating factor receptor alpha chain (GM-CSFRalpha), and these data corresponded well to the growth responsiveness to the cytokines. IL-2Ralpha expression was also found in all t(16;21) samples, but IL-2 did not act on the proliferation of the leukaemic cells in in vitro cultures. G-CSF distinctly promoted the proliferation of leukaemic cells of t(16;21) AML, but did not enhance the expression of MPO and neutrophil differentiation of these cells. Our findings indicate that AML cells with t(16;21) preserve stem cell properties such as CD34 and c-kit expression, and suggest that they have the potential to differentiate into a monocytic lineage. The relationship between the unique cellular characteristics (especially CD56 and IL-2Ralpha expression) and FUS/ERG protein remains undetermined.

Retroviral transduction of TLS-ERG initiates a leukemogenic program in normal human hematopoietic cells

Many chimeric oncogenes have been identified by virtue of the association between chromosomal translocation and specific human leukemias. However, the biological mechanism by which these oncogenes disrupt the developmental program of normal human hematopoietic cells during the initiation of the leukemogenic process is poorly understood due to the absence of an appropriate experimental system to study their function. Here, we report that retroviral transduction of TLS-ERG, a myeloid leukemia-associated fusion gene, to human cord blood cells results in altered myeloid and arrested erythroid differentiation and a dramatic increase in the proliferative and self-renewal capacity of transduced myeloid progenitors. Thus, TLS-ERG expression alone induced a leukemogenic program that exhibited similarities to the human disease associated with this translocation. These results provide an experimental examination of the early stages of the human leukemogenic process induced by a single oncogene and establish a paradigm to functionally assay putative leukemogenic genes in normal human hematopoietic cells.