Fig. 3: CircPSMA1 functions as a sponge of miR-637.

A The 10 potential targeted miRNAs of circPSMA1 were predicted by three databases. The green circle means circPSMA1 and red rectangle indicates the targeted miRNAs. The image shows the binding sites of circRNA-miRNAs. B The signaling pathways of the 10 miRNAs were analyzed by DIANA-miRPath v3.0 (http://snf-515788.vm.okeanos.grnet.gr/). C The expression levels of these candidate miRNAs after cotransfected with luc-circPSMA1 (plasmid that overexpressed circPSMA1 and labeled with luciferase) or luc-circ-NC (plasmid that overexpressed circ-NC and labeled with luciferase) with candidate miRNA mimics. D Schematic illustration of circPSMA1-WT and circPSMA1-Mut luciferase reporter vectors and the miR-637 binding site on circPSMA1 predicted by miRanda. E The dual-luciferase reporter assay was carried out to validate whether miR-637 could directly bind to circPSMA1. After cotransfected circPSMA1-WT or circPSMA1-Mut luciferase reporter vectors with miR-637 mimic or NC respectively, the relative luciferase activities were detected by spectramax. F, G The qRT-PCR analysis detected the relative expression of miR-637 after overexpression or knockdown of circPSMA1. H FISH assay displayed the cellular location of circPSMA1 (red) and miR-637 (green) in MDA-MB-231 cells (magnification, ×200, scale bar, 50 μm). I, L EdU assays showed the percentage of EdU-positive cells in BT-549 and MDA-MB-231 cells after overexpression or knockdown of miR-637 by mimic and inhibitor (magnification, ×100, Scale bar, 100 μm). M–O Transwell assays detected the migration abilities of TNBC cells after overexpression or knockdown of miR-637 by transfected with miR-637 mimic, miR-637 inhibitor or their NC (mimic-NC and inhibitor-NC) (magnification, ×100, Scale bar, 100 μm). Data were shown as mean ± SD at least three independent experiments, *p < 0.05, **p < 0.01.