Abstract
Multiple myeloma (MM) is a heterogeneous disease with a poor prognosis. Circulating microRNAs (miRNAs) have shown potential as non-invasive prognostic biomarkers for heterogeneous diseases. miR-20a has been shown involved in various human cancers, and the phosphatase and tensin homolog/phosphoinositide 3-kinase/protein kinase B (PTEN/P13K/Akt) signaling pathway plays a key role in cell proliferation, migration and apoptosis. Here, we investigated the effect of miR-20a on the PTEN/PI3K/Akt signaling pathway during MM cell proliferation, migration and apoptosis. Reverse transcription quantitative polymerase chain reaction was applied to detect miR-20a expression in plasma from 30 MM patients and MM cell lines. CCK-8 assays, Transwell assays, Annexin V/PI double-staining and western blotting were performed to examine the protein expressions of PTEN, PI3K and Akt during cellullar proliferation, migration, cycling, and apoptosis. Significant upregulation of miR-20a and deregulation of PTEN were observed in MM cells. We also identified PTEN as a downstream target gene of miR-20a, which bound to the 3'-untranslated region of PTEN. Overexpression of miR-20a was associated with decreased PTEN expression, and treatment with miR-20a inhibitors decreased cell proliferation, migration and clonogenicity and reduced the protein expressions of PI3K and p-Akt but increased PTEN protein expression compared with blank and negative control groups. Taken together, these results showed that inhibition of miR-20a suppresses MM progression by modulating the PTEN/PI3K/Akt signaling pathway. These findings suggest that miR-20a may be a novel molecular therapeutic target for the treatment of MM.