Myeloid Progenitor Cell Proliferation and Mobilization Effects of BB10010, a Genetically Engineered Variant of Human Macrophage Inflammatory Protein-1α, in a Phase I Clinical Trial in Patients with Relapsed/Refractory Breast Cancer

1998 ◽  
Vol 24 (1) ◽  
pp. 14-30 ◽  
Author(s):  
Hal E Broxmeyer ◽  
Attilio Orazi ◽  
Nancy L Hague ◽  
George W Sledge ◽  
Henrik Rasmussen ◽  
...  
Science ◽  
2020 ◽  
Vol 367 (6477) ◽  
pp. 586-590 ◽  
Author(s):  
Hannah J. Uckelmann ◽  
Stephanie M. Kim ◽  
Eric M. Wong ◽  
Charles Hatton ◽  
Hugh Giovinazzo ◽  
...  

The initiating mutations that contribute to cancer development are sometimes present in premalignant cells. Whether therapies targeting these mutations can eradicate premalignant cells is unclear. Acute myeloid leukemia (AML) is an attractive system for investigating the effect of preventative treatment because this disease is often preceded by a premalignant state (clonal hematopoiesis or myelodysplastic syndrome). In Npm1c/Dnmt3a mutant knock-in mice, a model of AML development, leukemia is preceded by a period of extended myeloid progenitor cell proliferation and self-renewal. We found that this self-renewal can be reversed by oral administration of a small molecule (VTP-50469) that targets the MLL1-Menin chromatin complex. These preclinical results support the hypothesis that individuals at high risk of developing AML might benefit from targeted epigenetic therapy in a preventative setting.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2892-2892
Author(s):  
Georgios Nteliopoulos ◽  
Stephen B Marley ◽  
Myrtle Y Gordon

Abstract We have used a colony replating assay in conjunction with manipulation of the Wnt and PI-3K pathways to investigate regulation of myeloid progenitor cell proliferation/differentiation. We found that PI-3 kinase pathway via Akt acts as a proliferative brake and promotes differentiation in IL3-driven myelopoiesis, since inhibition of PI-3K/Akt pathway with LY294002 (PI-3 kinase inhibitor) and SH-5 (Akt inhibitor) increased proliferation (reduced differentiation). We investigated the involvement of Wnt signalling in CFU-GM proliferation by using exogenous recombinant canonical Wnt3a and non-canonical Wnt5a. We showed that both of the Wnt members cannot support colony growth alone, but when added to IL3 they increased proliferation potential compared with the IL3 control, indicating an involvement of canonical Wnt/β-catenin and non-canonical Wnt pathways in the myeloid progenitor cell proliferation. Immunoblotting analysis indicated that Wnt5a acts independently of β-catenin. Dkk-1 (Wnt-pathway inhibitor) alone did not affect IL-3 dependent proliferation but when combined with recombinant Wnts as expected it abrogated the effects of Wnt3a but not Wnt5a (acts as canonical-Wnt inhibitor). This was confirmed by β-catenin protein levels. Surprisingly, when Dkk-1 was added to LY294002 or SH-5, it blocked their proliferative effects. Dkk-1 acts as functional Wnt-receptor disabler and the finding that it blocks proliferation induced by PI-3K/Akt inhibitors’ indicates a link between the PI-3K and the Wnt signalling pathways. We hypothesised that increased proliferation induced by LY294002 or SH-5 was not mediated by downstream activation of the Wnt pathway but by induced endogenous expression of Wnt proteins and activation of the surface receptor. We conclude that there is a production of endogenous Wnt proteins that increases proliferation. Endogenous Wnt production has been reported in primitive haematopoietic cells so there is potential for a paracrine or autocrine role for these cell regulators. We tested this hypothesis in CD34+ cells and found the addition of SH-5 to IL3 creates an autocrine loop of endogenous Wnt production, which results in the phosphorylation and activation of the LRP6 receptor and the initiation of the canonical signalling pathway. Furthermore, the conditioned medium of cultured CD34+ cells was concentrated by using filtration devices (30kD cut-off) and added to IL3 to support the growth of progenitors of another sample in a CFU-GM assay. We indicated that Wnt production and secretion can act in a paracrine way as well, since IL3+SH-5 conditioned medium increased the proliferative index of CFU-GM cells whereas IL3 conditioned medium did not have significant effect. Dkk-1 abrogated the IL3+SH-5 conditioned medium’s induced proliferation, suggesting that the growth factors that had the proliferative effects were Wnt members. In conclusion, our data suggest that IL3 via PI-3K pathway promotes differentiation of progenitor myeloid cells through inhibition of endogenous Wnt production.


2007 ◽  
Vol 35 (4) ◽  
pp. 78-86 ◽  
Author(s):  
Hal E. Broxmeyer ◽  
Ji Li ◽  
Giao Hangoc ◽  
Scott Cooper ◽  
Wen Tao ◽  
...  

Blood ◽  
1995 ◽  
Vol 85 (12) ◽  
pp. 3412-3415 ◽  
Author(s):  
BI Lord ◽  
LB Woolford ◽  
LM Wood ◽  
LG Czaplewski ◽  
M McCourt ◽  
...  

BB-10010 is a genetically engineered variant of human macrophage inflammatory protein-1 alpha with improved solution properties. We show here that it mobilizes stem cells into the peripheral blood. We investigated the mobilizing effects of BB-10010 on the numbers of circulating 8-day spleen colony-forming units (CFU-S8), CFU-S12, and progenitors with marrow repopulating ability (MRA). A single subcutaneous dose of BB-10010 caused a twofold increase in circulating numbers of CFU-S8, CFU-S12, and MRA 30 minutes after dosing. We also investigated the effects of granulocyte colony-stimulating factor (G-CSF) and the combination of G-CSF with BB-10010 on progenitor mobilization. Two days of G-CSF treatment increased circulating CFU-S8, CFU-S12, and MRA progenitors by 25.7-, 19.8-, and 27.7-fold. A single administration of BB-10010 after 2 days of G-CSF treatment increased circulating CFU-S8, CFU-S12, and MRA even further to 38-, 33-, and 100-fold. Splenectomy resulted in increased circulating progenitor numbers but did not change the pattern of mobilization. Two days of treatment with G-CSF then increased circulating CFU-S8, CFU-S12, and MRA by 64-, 69-, and 32-fold. A single BB-10010 administration after G-CSF treatment further increased them to 85-, 117-, and 140-fold, respectively, compared with control. We conclude that BB-10010 causes a rapid increase in the number of circulating hematopoietic progenitors and further enhances the numbers induced by pretreatment with G-CSF. BB-10010 preferentially mobilized the more primitive progenitors with marrow repopulating activity, releasing four times the number achieved with G-CSF alone. Translated into a clinical setting, this improvement in progenitor cell mobilization may enhance the efficiency of harvest and the quality of grafts for peripheral blood stem cell transplantation.


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