Van Belle Siska, El Ashkar Sara, Čermáková Kateřina, Matthijssens Filip, Goossens Steven, Canella Alessandro, Hodges Courtney H, Christ Frauke, De Rijck Jan, Van Vlierberghe Pieter, Veverka Václav, Debyser Zeger
Laboratory for Molecular Virology and Gene Therapy, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Flanders, Belgium.
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, 166 10 Prague 6, Czech Republic.
Cells. 2021 Jan 19;10(1):192. doi: 10.3390/cells10010192.
HDGF-related protein 2 (HRP-2) is a member of the Hepatoma-Derived Growth Factor-related protein family that harbors the structured PWWP and Integrase Binding Domain, known to associate with methylated histone tails or cellular and viral proteins, respectively. Interestingly, HRP-2 is a paralog of Lens Epithelium Derived Growth Factor p75 (LEDGF/p75), which is essential for -rearranged (-r) leukemia but dispensable for hematopoiesis. Sequel to these findings, we investigated the role of HRP-2 in hematopoiesis and -r leukemia. Protein interactions were investigated by co-immunoprecipitation and validated using recombinant proteins in NMR. A systemic knockout mouse model was used to study normal hematopoiesis and MLL-ENL transformation upon the different HRP-2 genotypes. The role of HRP-2 in -r and other leukemic, human cell lines was evaluated by lentiviral-mediated miRNA targeting HRP-2. We demonstrate that MLL and HRP-2 interact through a conserved interface, although this interaction proved less dependent on menin than the MLL-LEDGF/p75 interaction. The systemic HRP-2 knockout mice only revealed an increase in neutrophils in the peripheral blood, whereas the depletion of HRP-2 in leukemic cell lines and transformed primary murine cells resulted in reduced colony formation independently of -rearrangements. In contrast, primary murine HRP-2 knockout cells were efficiently transformed by the MLL-ENL fusion, indicating that HRP-2, unlike LEDGF/p75, is dispensable for the transformation of MLL-ENL leukemogenesis but important for leukemic cell survival.
肝癌衍生生长因子相关蛋白2（HRP-2）是肝癌衍生生长因子相关蛋白家族的成员，该家族含有结构化的PWWP和整合酶结合结构域，已知分别与甲基化组蛋白尾巴或细胞及病毒蛋白相关联。有趣的是，HRP-2是晶状体上皮衍生生长因子p75（LEDGF/p75）的旁系同源物，LEDGF/p75对混合谱系白血病重排（MLL-r）白血病至关重要，但对造血过程并非必需。基于这些发现，我们研究了HRP-2在造血和MLL-r白血病中的作用。通过免疫共沉淀研究蛋白质相互作用，并使用重组蛋白在核磁共振中进行验证。使用全身性基因敲除小鼠模型研究不同HRP-2基因型对正常造血和MLL-ENL转化的影响。通过慢病毒介导的靶向HRP-2的微小RNA评估HRP-2在MLL-r和其他白血病人类细胞系中的作用。我们证明MLL和HRP-2通过一个保守界面相互作用，尽管这种相互作用比MLL-LEDGF/p75相互作用对Menin的依赖性更小。全身性HRP-2基因敲除小鼠仅在外周血中显示中性粒细胞增加，而白血病细胞系和转化的原代小鼠细胞中HRP-2的缺失导致集落形成减少，且与MLL重排无关。相反，原代小鼠HRP-2基因敲除细胞可被MLL-ENL融合有效转化，这表明与LEDGF/p75不同，HRP-2对MLL-ENL白血病发生的转化并非必需，但对白血病细胞存活很重要。
