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. Materials and methods. Gene expression microarrays from GEO DataSets database, quantitative realtime 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 gain- and 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.