| First Author | Wallace JA | Year | 2017 |
| Journal | Blood | Volume | 129 |
| Issue | 23 | Pages | 3074-3086 |
| PubMed ID | 28432220 | Mgi Jnum | J:243341 |
| Mgi Id | MGI:5908281 | Doi | 10.1182/blood-2016-09-740209 |
| Citation | Wallace JA, et al. (2017) miR-155 promotes FLT3-ITD-induced myeloproliferative disease through inhibition of the interferon response. Blood 129(23):3074-3086 |
| abstractText | FLT3-ITD+ acute myeloid leukemia (AML) accounts for approximately 25% of all AML cases and is a subtype that carries a poor prognosis. microRNA-155 (miR-155) is specifically overexpressed in FLT3-ITD+ AML compared with FLT3 wild-type (FLT3-WT) AML and is critical for the growth of FLT3-ITD+ AML cells in vitro. However, miR-155's role in regulating FLT3-ITD-mediated disease in vivo remains unclear. In this study, we used a genetic mouse model to determine whether miR-155 influences the development of FLT3-ITD-induced myeloproliferative disease. Results indicate that miR-155 promotes FLT3-ITD-induced myeloid expansion in the bone marrow, spleen, and peripheral blood. Mechanistically, miR-155 increases proliferation of the hematopoietic stem and progenitor cell compartments by reducing the growth-inhibitory effects of the interferon (IFN) response, and this involves targeting of Cebpb. Consistent with our observations in mice, primary FLT3-ITD+ AML clinical samples have significantly higher miR-155 levels and a lower IFN response compared with FLT3-WT AML samples. Further, inhibition of miR-155 in FLT3-ITD+ AML cell lines using CRISPR/Cas9, or primary FLT3-ITD+ AML samples using locked nucleic acid antisense inhibitors, results in an elevated IFN response and reduces colony formation. Altogether, our data reveal that miR-155 collaborates with FLT3-ITD to promote myeloid cell expansion in vivo and that this involves a multitarget mechanism that includes repression of IFN signaling. |
