Fig. 4

CircMAPK9 exerted its functions by sponging miR-140-3p in RA-FLSs. RA-FLSs were transfected with si-NC, si-circMAPK9#2, si-circMAPK9#2 + anti-miR-NC, or si-circMAPK9#2 + anti-miR-140-3p. A The level of miR-140-3p was examined by qRT-PCR. B MTT assay was conducted to evaluate cell proliferation. C, D Flow cytometry analysis was employed to measure the apoptosis rate and cell cycle distribution. E, F Transwell assay examined cell migration and invasion. G The protein levels of Bax, Bcl-2, MMP2, and MMP9 were determined by western blot. H–J The secretion of TNF-α, IL-1β, and IL-6 was tested by ELISA. *P < 0.05