Ran Weissman, Eli L Diamond, Julien Haroche, Benjamin H Durham, Fleur Cohen, Justin Buthorn, Zahir Amoura, Jean-François Emile, Roei D Mazor, Noam Shomron, Omar I Abdel-Wahab, Ofer Shpilberg, Oshrat Hershkovitz-Rokah
Leukemia 2022 AprErdheim-Chester disease (ECD) is characterized by excessive production and accumulation of histiocytes within multiple tissues and organs. ECD patients harbor recurrent mutations of genes associated with the RAS/RAF/MEK/ERK signaling pathway, particularly, the BRAFV600E mutation. Following our previous finding that miR-15a-5p is the most prominently downregulated microRNA in ECD patients compared to healthy individuals, we elucidated its role in ECD pathogenesis. Bioinformatics analysis followed by a luciferase assay showed that chemokine ligand 10 (CXCL10) is a target gene regulated by miRNA-15a-5p. This was confirmed in 24/34 ECD patients that had low expression of miR-15a-5p concurrent with upregulated CXCL10. Overexpression of miR-15a-5p in cell lines harboring BRAF or RAS mutations (Ba/F3, KG-1a and OCI-AML3) resulted in CXCL10 downregulation, followed by LIN28a and p-ERK signaling downregulation and let-7 family upregulation. Overexpression of miR-15a-5p inhibited cell growth and induced apoptosis by decreasing Bcl-2 and Bcl-xl levels. Analysis of sequential samples from 7 ECD patients treated with MAPK inhibitors (vemurafenib/cobimetinib) for 4 months showed miR-15a-5p upregulation and CXCL10 downregulation. Our findings suggest that miR-15a-5p is a tumor suppressor in ECD through the CXCL10-ERK-LIN28a-let7 axis, highlighting another layer of post-transcriptional regulation in this disease. Upregulation of miR-15a-5p in ECD patients may have a potential therapeutic role. © 2021. The Author(s).
Ran Weissman, Eli L Diamond, Julien Haroche, Benjamin H Durham, Fleur Cohen, Justin Buthorn, Zahir Amoura, Jean-François Emile, Roei D Mazor, Noam Shomron, Omar I Abdel-Wahab, Ofer Shpilberg, Oshrat Hershkovitz-Rokah. MicroRNA-15a-5p acts as a tumor suppressor in histiocytosis by mediating CXCL10-ERK-LIN28a-let-7 axis. Leukemia. 2022 Apr;36(4):1139-1149
PMID: 34785791
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