hsa_circ_0017842 acts as a competing endogenous RNA to enhance the malignancy of gastric cancer.

BACKGROUND: Circular RNAs (circRNAs) have been shown to act as competing endogenous RNAs (ceRNAs) participating in the progression of gastric cancer (GC). OBJECTIVES: Our study aimed to investigate whether hsa_circ_0017842 can affect the malignancy of GC in a ceRNA manner. MATERIAL AND METHODS: Gene expression microarrays from GEO DataSets database, quantitative real-time polymerase chain reaction (qPCR) and western blotting were used to identify the expression levels of hsa_circ_0017842, miR-1294, and secreted protein, acidic and rich in cysteine (SPARC) in GC. The function of hsa_circ_0017842/miR-1294/SPARC axis in GC cells was confirmed using gainand loss-of-function assays. In addition, luciferase and RNA pulldown assays were performed to demonstrate the ceRNA mechanism of hsa_circ_0017842 involving miR-1294 and SPARC. RESULTS: The upregulation of hsa_circ_0017842 and SPARC, and downregulation of miR-1294 were observed in GC. Upregulating hsa_circ_0017842 in GC cells led to an increase in their proliferation, migration and invasion, and hsa_circ_0017842 knockdown showed the opposite effects on GC cells. Moreover, hsa_circ_0017842 was shown to be a sponge for miR-1294, thereby regulating SPARC expression. Due to the targeting relationship among hsa_circ_0017842, miR-1294 and SPARC, SPARC knockdown could relieve the effect of hsa_circ_0017842 overexpression on GC cells. CONCLUSIONS: Overall, this study confirmed that hsa_circ_0017842 acted as a ceRNA to promote the malignancy of GC cells through regulating the miR-1294/SPARC axis. Our findings might help better elucidate the molecular mechanism of GC tumorigenesis, and as a result improve the overall survival of GC patients.