Downregulation of circular RNA hsa_circ_0087856 sensitizes bladder cancer cells to cisplatin through targeting miR-1184/CITED2 signaling

CircRNAs are considered as one of the potential therapeutic targets of multiple cancers. According to accumulating evidence, circRNA regulates cancer progression by acting as a miRNA sponge. In the current work, our data discovered that hsa_circ_0087856 and CITED2 expression was increased, while miR-1184 expression was decreased in BC cell lines and tissues. Hsa_circ_0087856 expression negatively correlated with miR-1184, whereas positively correlated with CITED2. Hsa_circ_0087856 silencing suppressed BC tumor growth, and contributed to the inhibition of cisplatin to tumor growth. In cellular experiments, hsa_circ_0087856 increasing promoted BC cells proliferation, migration and invasion, and inhibited the cells apoptosis. Hsa_circ_0087856 increasing partly reversed the inhibition of cisplatin to BC cell proliferation and the promotion to cell apoptosis. Oppositely, hsa_circ_0087856 silencing could increase the sensitivity of BC cells to cisplatin. Hsa_circ_0087856 promoted CITED2 expression through binding with miR-1184 and inhibiting its expression. CITED2 increasing partly reversed the promotion of hsa_circ_0087856 silencing to cisplatin-induced BC cells apoptosis promotion and proliferation suppression. Overall, our results revealed the role of hsa_circ_0087856 that downregulation its expression could enhance the BC cells sensitivity to cisplatin by facilitating CITED expression via sponging miR-1184. Moreover, our research provided a potential therapeutic target for BC.