RETRACTED ARTICLE: The circRNA circAGFG1 acts as a sponge of miR-195-5p to promote triple-negative breast cancer progression through regulating CCNE1 expression

Abstract

BackgroundIn recent years, circular RNAs (circRNAs), a new star of non-coding RNA, have been emerged as vital regulators and gained much attention for involvement of initiation and progression of diverse kinds of human diseases, especially cancer. However, regulatory role, clinical significance and underlying mechanisms of circRNAs in triple-negative breast cancer (TNBC) still remain largely unknown.MethodsHere, the expression profile of circRNAs in 4 pairs of TNBC tissues and adjacent non-tumor tissues was analyzed by RNA-sequencing. Quantitative real-time PCR and in situ hybridization were used to determine the level and prognostic values of circAGFG1 in two TNBC cohorts. Then, functional experiments in vitro and in vivo were performed to investigate the effects of circAGFG1 on tumor growth and metastasis in TNBC. Mechanistically, fluorescent in situ hybridization, dual luciferase reporter assay, RNA pull-down and RNA immunoprecipitation experiments were performed to confirm the interaction between circAGFG1 and miR-195-5p in TNBC.ResultsWe found that circAGFG1 was evidently up-regulated in TNBC, and its level was correlated with clinical stage, pathological grade and poor prognosis of patients with TNBC. The results indicated that circAGFG1 could promote TNBC cell proliferation, mobility and invasion as well as tumorigenesis and metastasis in vivo. Mechanistic analysis showed that circAGFG1 may act as a ceRNA (competing endogenous RNA) of miR-195-5p to relieve the repressive effect of miR-195-5p on its target cyclin E1 (CCNE1).ConclusionsOur findings suggest that circAGFG1 promotes TNBC progression through circAGFG1/miR-195-5p/CCNE1 axis and it may serve as a new diagnostic marker or target for treatment of TNBC patients.Electronic supplementary materialThe online version of this article (10.1186/s12943-018-0933-7) contains supplementary material, which is available to authorized users.

hsa_circ_0062389 promotes the progression of non-small cell lung cancer by sponging miR-103a-3p to mediate CCNE1 expression

“…Hui et al showed that miR-195 suppressed the glioma cells proliferation via targeting CCND1 and CCNE1 [24] . Yang et al found that circRNA circAGFG1 served as a sponge of miR-195-5p to promote breast cancer progression by regulating CCNE1 expression [25] . In the present study, we found that CCNE1 expression was significantly increased in NSCLC patients and correlated with poor prognosis.…”

circFBXL5 promotes breast cancer progression by sponging miR‐660

“…11 In triple-negative breast cancer, circAGFG1 acted as a ceRNA for miR-195 to regulate cyclin E1 and promote cancer progression. 12 And hsa_circ_001783 was reported to promote breast cancer progression via sponging miR-200c. 13 Here, we found that circFBXL5 had binding sites for miR-660 and could function as a miR-660 sponge.…”

CircAGFG1 sponges miR‐203 to promote EMT and metastasis of non‐small‐cell lung cancer by upregulating ZNF281 expression

“…CircAGFG1‐siRNA, two ZNF281‐siRNAs and negative control (NC) siRNAs plasmids were designed, synthesized and purchased from GenePharma, China by using the pPG‐miR‐eGFP‐Blasticidin vector with has‐miR‐203 (pPG‐miR‐203) or hsa‐miR‐203 inhibitors (pPG‐anti‐miR‐203) or NC (pPG‐miR‐NC). The SiRNA sequences were as follows: 5′‐ATGCAGGCGAGGATTAAAT‐3′ for si‐circAGFG1 and 5′‐CCAGAATCTCAGGGAATCA‐3′ for si‐ZNF281‐1 . All siRNA sequences were synthesized and purchased form GenePharma, China.…”

“…Furthermore, circFGFR3 enhances tumor progression in NSCLC . Yang et al . demonstrated that circAGFG1 promotes triple negative breast cancer progression through regulating CCNE1 expression.…”