Circ_0025908 regulates cell vitality and proliferation via miR-137/HIPK2 axis of rheumatic arthritis

BACKGROUND: Rheumatic arthritis (RA) is an autoimmune disease with bad effects. Recent researches have shown that circular RNAs (circRNAs) could affect the progress of RA, but the mechanism still indistinct. In this work, we explored the roles of circ_0025908 in RA. METHODS: The levels of circ_0025908, microRNA-137 (miR-137), and mRNA of homeodomain-interacting protein kinase 2 (HIPK2) were detected by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) in RA tissues. Meanwhile, the level of HIPK2 was quantified by Western blot analysis. Besides, the cell functions were examined by CCK8 assay, EdU assay, flow cytometry assay, ELISA, and Western blot. Furthermore, the interplay between miR-137 and circ_0025908 or HIPK2 was detected by dual-luciferase reporter assay. RESULTS: The levels of circ_0025908 and HIPK2 were upregulated, and the miR-137 level was decreased in RA tissues in contrast to that in normal tissues. For functional analysis, circ_0025908 deficiency inhibited cell vitality, cell mitotic cycle, cell proliferation, and immunoreaction in RA cells, whereas promoted cell apoptosis. Moreover, miR-137 was confirmed to repress the progression of RA cells by suppressing HIPK2. In mechanism, circ_0025908 acted as a miR-137 sponge to regulate the level of HIPK2. CONCLUSION: Circ_0025908 facilitates the development of RA through increasing HIPK2 expression by regulating miR-137, which also offered an underlying targeted therapy for RA treatment.