BackgroundCirc-ITCH is a circRNA generated from several exons of itchy E3 ubiquitin protein ligase (ITCH) and tumor suppressor served as a sponge for certain miRNAs targeting their parental transcripts of ITCH. However, the role of circ-ITCH in bladder cancer (BCa) was not reported. In the present study, we investigated the role of circ-ITCH in BCa.MethodsQuantitative real-time PCR was used to detect the expression of circ-ITCH and survival analysis was adopted to explore the association between circ-ITCH expression and the prognosis of BCa. BCa cells were stably transfected with lentivirus approach and cell proliferation, migration, invasion, cell cycle and cell apoptosis, as well as tumorigenesis in nude mice were performed to assess the effect of circ-ITCH in BCa. Biotin-coupled probe pull down assay, Biotin-coupled miRNA capture, Fluorescence in situ hybridization and Luciferase reporter assay were conducted to confirm the relationship between the circ-ITCH and the microRNA.ResultsIn the present study, we found that circ-ITCH, is down-regulated in BCa tissues and cell lines. BCa patients with low circ-ITCH expression had shortened survival. Enforced- expression of circ-ITCH inhibited cells proliferation, migration, invasion and metastasis both in vitro and in vivo. Mechanistically, we demonstrated that circ-ITCH up-regulates the expression of miR-17 and miR-224 target gene p21 and PTEN through ‘sponging’ miR-17 and miR-224, which suppressed the aggressive biological behaviors of BCa.Conclusionscirc-ITCH acts as a tumor suppressor by a novel circ-ITCH/miR-17, miR-224/p21, PTEN axis, which may provide a potential biomarker and therapeutic target for the management of BCa.Electronic supplementary materialThe online version of this article (10.1186/s12943-018-0771-7) contains supplementary material, which is available to authorized users.

The natural genetic variation in pre-miR-146a affects the amount of mature miR-146a, contributes to the genetic predisposition to CaP.

MicroRNAs have been implicated in regulating diverse cellular pathways. Emerging evidence indicates that miR-143 plays causal roles in cancer tumorigenesis as a tumor suppress gene; however, its role in prostate cancer tumorigenesis remains largely unknown. The aims of this study were to verify the effect of miR-143 on proliferation and migration abilities of prostate cancer cells. The expression level of miR-143 and its target gene KRAS were measured by realtime PCR and western blotting, respectively. Effects of miR-143 in cell proliferation, migration and chemosensitivity were evaluated by MTT assay, FACS cell cycle analysis, colony formation assay, and transwell migratory assay. Our results revealed an inverse correlation of expression between miR-143 and KRAS protein in prostate cancer samples (Pearson's correlation scatter plots: R = -0.707, P < 0.05). Moreover, over-expression of miR-143 in prostate cancer cells suppressed their proliferation and migration and increased their sensitivity to docetaxel by targeting EGFR/RAS/MAPK pathway. These findings suggest that miR-143 plays an important role in prostate cancer proliferation, migration and chemosensitivity by suppressing KRAS and subsequent inactivation of MAPK pathway, which provides a potential development of a new approach for the treatment of prostate cancer.