Circ_0021087 acts as a miR‐184 sponge and represses gastric cancer progression by adsorbing miR‐184 and elevating FOSB expression

Abstract

Background Gastric cancer (GC) ranks third among the causes of cancer‐related deaths in the world. Circular RNA hsa_circ_0021087 (circ_0021087) plays a repressive role in GC. Nevertheless, the mechanism by which circ_0021087 constrains GC advancement is unclear. Materials and Methods Expression patterns of circ_0021087, microRNA (miR)‐184 and FBJ murine osteosarcoma viral oncogene homolog B (FOSB) mRNA were assessed by quantitative real‐time polymerase chain reaction (RT‐qPCR). Gain‐of‐function experiments were conducted to verify the biological function of circ_0021087 in vitro and in vivo, including cell counting kit‐8 (CCK‐8), 5‐ethynyl‐2ʹ‐deoxyuridine (EdU), flow cytometry, transwell and xenograft assays. Protein levels were analysed by Western blotting and immunohistochemistry (IHC). The regulatory mechanism of circ_0021087 was analysed by bioinformatics analysis, dual‐luciferase reporter and RNA immunoprecipitation (RIP) assays. Results and Conclusion Circ_0021087 and FOSB were lowly expressed in GC, whereas miR‐184 had an opposite result. Circ_0021087 overexpression repressed GC cell proliferation and epithelial‐mesenchymal transition (EMT) in xenograft models in vivo and induced GC cell apoptosis, repressed GC cell proliferation, EMT, migration and invasion in vitro. Circ_0021087 could elevate FOSB expression by adsorbing miR‐184. MiR‐184 mimic reversed the inhibitory influence of circ_0021087 overexpression on GC cell malignancy. Also, FOSB knockdown offset the suppressive impact of miR‐184 silencing on GC cell malignancy. In conclusion, circ_0021087 played a repressive influence on GC progression by elevating FOSB expression by adsorbing miR‐184, offering a new mechanism for circ_0021087 to inhibit the progression of GC.

Circular RNA circLMO1 Suppresses Cervical Cancer Growth and Metastasis by Triggering miR-4291/ACSL4-Mediated Ferroptosis

“…The biological role of circLMO1 in gastric cancer has been studied in previous studies ( 26 , 27 ). However, the mechanism by which circLMO1 regulates cancer progression remains poorly understood.…”

“…Yu et al. showed that circLMO1 inhibits gastric cancer cell proliferation and invasion ( 27 ). In contrast, Han et al demonstrated that circLMO1 promotes gastric cancer cell proliferation ( 28 ).…”

“…Most circRNAs are located in cytoplasm (23,24), and frequently act as competing endogenous RNAs (ceRNAs) by sponging miRNAs, and thereby increasing downstream gene expression. Hsa_circ_0021087, also known as circLMO1, is a newly identified circRNA in gastric cancer (25)(26)(27). However, the role of circLMO1 in gastric cancer is controversial.…”

“…However, the role of circLMO1 in gastric cancer is controversial. Yu et al demonstrated that circLMO1 overexpression decreases gastric cancer cell proliferation and invasion ( 27 ). In contrast, Han et al showed that circLMO1 promotes gastric cancer cell proliferation ( 28 ).…”

Non-Coding RNAs in Gastric Cancer: From Malignant Hallmarks to Clinical Applications

“…Peng et al demonstrated that circCUL2 modulates GC malignant transformation through miR-142-3p/ROCK2-mediated autophagy activation ( Peng L. et al, 2020 ). Recently, Yu et al revealed that highly expressed circ_0021087 induces GC cell apoptosis via the miR-184/FOSB axis ( Yu et al, 2021 ).…”