NG2 antigen is expressed in CD34+ HPCs and plasmacytoid dendritic cell precursors: is NG2 expression in leukemia dependent on the target cell where leukemogenesis is triggered? Bueno, C Montes, R Martín, L Prat I Hernandez MC Orfao A Menendez, P The study explored the expression of NG2 (Neuron-glial antigen 2) in human leukemias, focusing on its relationship with MLL (mixed-lineage leukemia) gene rearrangements. NG2, initially identified on oligodendrocyte progenitor cells, has shown controversial expression patterns in leukemia. Some studies suggested NG2 was linked specifically to MLL rearrangements, particularly those involving the t(4;11) and t(9;11) translocations. However, there are cases where leukemias with MLL rearrangements do not express NG2, and other types of leukemia, like plasmacytoid dendritic cell (pDC) leukemia, express NG2 without MLL rearrangements. The authors investigated several leukemia cell lines with and without MLL translocations. The results showed that NG2 expression was not uniformly associated with MLL rearrangements. For instance, both the MV4;11 and RS4;11 cell lines, which share MLL-AF4 fusion, exhibited differing NG2 expression profiles. Additionally, NG2 expression was observed in hematopoietic and non-hematopoietic cell lines lacking MLL rearrangements, further suggesting that NG2 expression in leukemia is not strictly dependent on MLL fusion genes. The study also hypothesized that NG2 expression might be linked to the cell of origin for leukemia, particularly in hematopoietic stem/progenitor cells (HSPCs). A subset of CD34+ HSPCs expressed NG2, which could be relevant for leukemogenesis, as NG2+ pDC precursors were found in cord blood. The research also considered the potential role of NG2 in leukemias arising from very early hematopoiesis, including in human embryonic stem cells (hESCs), which expressed NG2. Overall, the study suggests that NG2 expression in leukemia is not necessarily linked to MLL gene rearrangements, but could be due to specific leukemic abnormalities that trigger NG2 expression in certain cell subsets. More studies are needed to fully understand the clinical significance of NG2 in leukemias. 2025-01-28T10:34:25Z 2025-01-28T10:34:25Z 2008 journal article https://hdl.handle.net/10481/100705 10.1038/leu.2008.134 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ open access Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License