hsa_circ_0092339 acts as a molecular sponge in castration-resistant prostate cancer via the hsa-mir-940/ axis.

We aimed to determine whether intronic circRNA acts as a molecular sponge in castration-resistant prostate cancer (CRPC). A gene chip technique was used to conduct sequencing. A qPCR experiment was performed to verify the result. Radioimmunoprecipitation, RNA pull-down and dual-luciferase reporter assays were performed to particularly expound its function. Verification of downstream effects was carried out through qPCR and western blot, and a xenograft assay was performed for verification. Intronic circRNA hsa_circ_0092339 in the nucleus was highly expressed in CRPC cell lines. hsa_circ_0092339 did not regulate the expression of its parental gene. hsa_circ_0092339 functions like a molecular sponge, preventing degradation of mRNA by absorbing hsa-mir-940. hsa_circ_0092339 plays a critical role in CRPC through targeting indirectly by absorbing hsa-mir-940.