A novel circular RNA, circFAT1(e2), inhibits gastric cancer progression by targeting miR-548g in the cytoplasm and interacting with YBX1 in the nucleus

• Published in: Cancer letters 2019-02, Vol.442, p.222-232
• Main Authors: Fang, Jian, Hong, Han, Xue, Xiaofeng, Zhu, Xinguo, Jiang, Linhua, Qin, Mingde, Liang, Hansi, Gao, Ling
• Format: Article
• Language: English
• Subjects: Binding sites; Bioinformatics; Biomarkers; Cell adhesion & migration; Cell lines; Cell migration; Cell proliferation; circFAT1(e2); Circular RNA; Cytoplasm; Fluorescence; Fluorescence in situ hybridization; Gastric cancer; Gene expression; Hybridization; Migration; miR-548g; miRNA; Nuclei (cytology); Proteins; RNA polymerase; RUNX1; Runx1 protein; Science; Tissues; Tumor suppressor genes; Y-box binding protein-1 (YBX1)
• ISSN: 0304-3835; 1872-7980
• DOI: 10.1016/j.canlet.2018.10.040

In the present study, two circular RNA (circRNA) expression profiles in paired gastric cancer (GC) tissues from the GEO database were examined. We identified a novel circRNA, has_circ_0001461, which we termed circFAT1(e2). We verified that circFAT1(e2) was significantly downregulated in GC tissues and cell lines and was correlated with overall survival of GC patients. Fluorescence in situ hybridization (FISH) analysis showed that circFAT1(e2) was distributed in the cytoplasm of GC cells, as well as in the nucleus. Functional assays indicated that overexpression of circFAT1(e2) inhibited GC cell proliferation, migration and invasion. Then, we investigated whether circFAT1(e2) acts as a sponge of microRNA-549g(miR-548g) and regulates the expression of tumor suppressor RUNX1 in GC cells. Moreover, we found that nucleus-located circFAT1(e2) could directly interact with Y-box binding protein-1 (YBX1) and inhibit its function. In conclusion, circFAT1(e2) may play a role as a tumor suppressor in GC cells by regulating the miR-548g/RUNX1 axis in the cytoplasm and targeting YBX1 in the nucleus. [Display omitted] •We identified a novel circular RNA, circFAT1(e2), acted as a tumor suppressor in Gastric cancer.•CircFAT1(e2) sponges miR-548g in Gastric cancer cells.•CircFAT1(e2)/miR-548g axis regulates RUNX1 in Gastric cancer cells.•CircFAT1(e2) inhibited Gastric cancer cell tumorigenesis through directly bind to YBX1.