The microRNA miR-19a-3p suppresses cell growth, migration, and invasion in multiple myeloma via the Wnt/β-catenin pathway

BACKGROUND: MicroRNAs have been suggested as potential regulators in the development of multiple myeloma (MM) through affecting the expression of their target genes. This study aimed to investigate the effects of miR-19a-3p in MM, and its underlying mechanisms in regulating cell proliferation and invasion. METHODS: Bone marrow samples from 25 MM patients and 12 healthy donors were collected and miR-19a-3p and Wnt1 mRNA expression was assessed. The effects of miR-19a-3p on cell proliferation, migration, and invasion in U226 and RPMI-8226 MM cells were evaluated by miR-19a-3p overexpression. Luciferase assays were performed to explore the potential target genes. Knock down or overexpression of Wnt1 was used to explore the effects of miR-19a-3p on cell growth, migration, and invasion. RESULTS: The expression of miR-19a-3p was downregulated in MM and cell lines, while Wnt1 mRNA levels were increased. Overexpression of miR-19a-3p inhibited cell proliferation, migration, and invasion in U226 and RPMI-8226 cells. Additionally, western blot assays revealed that miR-19a-3p could suppress Wnt1, β-catenin, cyclin D1, and c-Myc expression. Knockdown of Wnt1 also inhibited cell growth, migration, and invasion. Moreover, luciferase reporter assay revealed direct binding between Wnt1 and miR-19a-3p. Wnt1 overexpression partially reversed the suppressive effects of miR-19a-3p on cell proliferation, migration, and invasion in U266 cells. CONCLUSIONS: The expression of miR-19a-3p was downregulated in MM patients and MM cell lines. Overexpression of miR-19a-3p inhibited proliferation, migration, and invasion by targeting Wnt1 via the Wnt/β-catenin signaling pathway.