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Purification of Human S100A12 and Its Ion-induced Oligomers for Immune Cell Stimulation
Published on: September 29, 2019
Regulation of S100A10 by the PML-RAR-α oncoprotein
Paul A O'Connell1, Patricia A Madureira, Jason N Berman
1Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, USA.
Abstract:
Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia that results from the expression of the promyelocytic leukemia-retinoic acid receptor α (PML-RAR-α) oncoprotein. It is characterized by severe hemorrhagic complications due in part to excessive fibrinolysis, resulting from the excessive generation of the fibrinolytic enzyme, plasmin, at the cell surface of the PML cells. The treatment of patients with all-trans retinoic acid (ATRA) effectively ameliorates the disease by promoting the destruction of the PML-RAR-α oncoprotein. In the present study we show for the first time that the plasminogen receptor, S100A10, is present on the extracellular surface of APL cells and is rapidly down-regulated in response to all-trans retinoic acid. The loss of S100A10 is concomitant with a loss in fibrinolytic activity. Furthermore, the induced expression of the PML-RAR-α oncoprotein increased the expression of cell surface S100A10 and also caused a dramatic increase in fibrinolytic activity. Depletion of S100A10 by RNA interference effectively blocked the enhanced fibrinolytic activity observed after induction of the PML-RAR-α oncoprotein. These experiments show that S100A10 plays a crucial role in the generation of plasmin leading to fibrinolysis, thus providing a link to the clinical hemorrhagic phenotype of APL.
Insights
S100A10, a plasminogen receptor on acute promyelocytic leukemia (APL) cells, drives excessive fibrinolysis and bleeding. All-trans retinoic acid (ATRA) treatment down-regulates S100A10, reducing fibrinolysis and improving APL outcomes.
Area of Science:
- Hematology
- Molecular Biology
- Oncology
Background:
- Acute promyelocytic leukemia (APL) is a subtype of acute myeloid leukemia characterized by the PML-RAR-α oncoprotein.
- APL patients often experience severe bleeding due to excessive fibrinolysis.
- All-trans retinoic acid (ATRA) is an effective treatment for APL, inducing PML-RAR-α oncoprotein destruction.
Purpose of the Study:
- To investigate the role of S100A10 in APL-associated fibrinolysis.
- To determine the effect of ATRA on S100A10 expression in APL cells.
- To establish a link between S100A10, fibrinolysis, and the hemorrhagic complications in APL.
Main Methods:
- Assessed S100A10 expression on the surface of APL cells.
- Measured fibrinolytic activity in response to ATRA treatment and PML-RAR-α oncoprotein induction.
- Utilized RNA interference to deplete S100A10 and evaluate its impact on fibrinolytic activity.
Main Results:
- S100A10 was identified as a cell surface plasminogen receptor on APL cells.
- ATRA treatment rapidly down-regulated S100A10, correlating with reduced fibrinolytic activity.
- PML-RAR-α oncoprotein induction increased S100A10 expression and fibrinolytic activity, which was blocked by S100A10 depletion.
Conclusions:
- S100A10 plays a critical role in cell surface plasmin generation and fibrinolysis in APL.
- S100A10 is a key mediator linking the PML-RAR-α oncoprotein to the excessive fibrinolysis observed in APL.
- Targeting S100A10 may offer a therapeutic strategy to mitigate hemorrhagic complications in APL.
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