Project description:Triple-negative breast cancer (TNBC) is the most aggressive form of breast cancer due to lack of effective targeted therapies. Here, we report that the expression of miR-4417 is suppressed during the progression of TNBC cells from non-malignant to the malignant stage. miR-4417 is localized to chromosome 1p36, a region with high loss of heterozygosity in multiple cancers, and its biogenesis is DICER-dependent. Low expression of miR-4417 is significantly associated with worse prognosis in TNBC patients, while overexpression of miR-4417 is sufficient to inhibit migration and tumorigenecity of TNBC cells in vitro. Overall, our findings suggest that miR-4417 exerts a tumor suppressive effect and thereby could serve as a prognostic biomarker and therapeutic tool against TNBC. We used microarrays to profile the global miRNA changes during EMT to identify putative tumor suppressors and prognostic biomarkers for TNBC.