English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Background  Breast cancer (BC) is one of the major malignancies worldwide. Circular ribonucleic acids (circRNAs) are a class of conserved ribonucleic acid (RNA) molecules that play important roles in various diseases. Recently, circRNAs have been suggested to have diagnostic value and may function as potential diagnostic biomarkers for BC. Previously, hsa_circ_0043278 was found to be downregulated in human BC. However, its role in human BC has not yet been identified.    Methods  The levels of hsa_circ_0043278 in BC cell lines were verified by quantitative reverse transcription–polymerase chain reaction (qRT–PCR). The overexpression vector and short hairpin RNA (shRNA) of hsa_circ_0043278 were transfected into MDA-MB-231 and MCF-7 cells, respectively. The effects of hsa_circ_0043278 on tumour cell growth, migration and invasion were measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT), colony formation, wound healing and Transwell assays  in vitro . A xenograft experiment was conducted to validate the inhibitory effect of hsa_circ_0043278 on tumour growth. The interaction between hsa_circ_0043278 and miR-455-3p was confirmed by a dual-luciferase reporter assay. Mimics and inhibitors of miR-455-3p were designed to confirm the influence of hsa_circ_0043278 on the hsa_circ_0043278/miR-455-3p/etoposide-induced gene 24 (EI24) axis.    Results  Hsa_circ_0043278 was downregulated in BC cell lines. Furthermore, overexpression of hsa_circ_0043278 notably decreased BC cell viability and inhibited BC cell migration and invasion  in vitro  and suppressed tumour growth  in vivo . Downregulation of hsa_circ_0043278 led to the opposite results. Hsa_circ_0043278 expression was negatively correlated with that of miR-455-3p. In addition, mechanistic investigation proved that hsa_circ_0043278 directly bound to miR-455-3p and regulated EI24 and NF-κB expression in BC cells.    Conclusion  Hsa_circ_0043278 acts as a tumour suppressor gene in BC through the hsa_circ_0043278/miR-455-3p/EI24 axis and may be regarded as a new prognostic predictor or potential therapeutic target in BC.    Supplementary Information  The online version contains supplementary material available at 10.1186/s12885-021-08989-w.

Circular RNA hsa_circ_0043278 inhibits breast cancer progression via the miR-455-3p/EI24 signalling pathway