Down-regulation of circ_0058058 suppresses proliferation, angiogenesis and metastasis in multiple myeloma through miR-338-3p/ATG14 pathway

BACKGROUND: Multiple myeloma (MM) is one of the most frequently diagnosed hematological malignancy. Dysregulation of circular RNAs (circRNAs) has important impacts on MM process. Herein, this work aimed to investigate the role and mechanism of circ_0058058 in MM progression. METHODS: Levels of genes and proteins were detected by real-time reverse transcription PCR (RT-qPCR) and Western blot. CCK-8 assay, colony formation assay, EdU assay, flow cytometry, tube formation assay, transwell assay and Western blot were utilized to detect the proliferation, apoptosis, angiogenesis and metastasis of MM cells. The target relationship between miR-338-3p and circ_0058058 or ATG14 (autophagy related 14) was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. In vivo experiments were performed using Xenograft assay. RESULTS: Circ_0058058 was up-regulated in MM bone marrow aspirates and cells, knockdown of circ_0058058 reduced MM cell proliferation, angiogenesis and metastasis, but induced apoptosis in vitro. In a MM xenograft mouse model, circ_0058058 silencing reduced MM tumor growth and cell proliferation. Mechanistically, circ_0058058 acted as a sponge for miR-338-3p to up-regulate ATG14 expression, which was validated to be a target of miR-338-3p. Rescue assay showed that miR-338-3p inhibition reversed the antitumor effects of circ_0058058 knockdown on MM cell. Moreover, forced expression of miR-338-3p suppressed MM cell malignant phenotype, which was abolished by ATG14 up-regulation. CONCLUSION: Circ_0058058 functions as a sponge for miR-338-3p to elevate ATG14 expression to promote MM cell proliferation, metastasis and angiogenesis, affording a potential therapeutic target for MM prevention.