microRNA-637 promotes apoptosis and suppresses proliferation and autophagy in multiple myeloma cell lines via NUPR1.

Multiple myeloma (MM) is a heterogeneous disease with poor prognosis. Increasing evidence has revealed that microRNAs (miRNAs) are strongly associated with the pathogenesis and progression of MM. Here, we investigated the role of microRNA-637 (miR-637) in MM to identify potential therapeutic targets. We measured the expression of miR-637 in bone marrow samples of MM patients and MM cell lines by quantitative real-time PCR and western blot. The effect of miR-637 on proliferation and apoptosis of MM primary cells was also investigated. Analyses of four bioinformatics databases showed that miR-637 is associated with nuclear protein 1 (NUPR1) in MM cells, which was confirmed by luciferase reporter assay. We found that the overexpression of miR-637 suppressed the development of MM. miR-637 mimics increased the levels of Bax, cleaved caspase 3, and P62, and decreased the levels of Bcl2 and LC3. Additionally, luciferase reporter assays were performed to demonstrate that NUPR1 is the main target of miR-637 in MM cells. Overexpression of NUPR1 reversed the effects of miR-637 mimics in MM cells. Our results suggest that miR-637 inhibits cell proliferation and autophagy, and promotes apoptosis in MM cells by targeting NUPR1. Our findings also suggest that miR-637 may have potential as a novel molecular therapeutic target for MM treatment.