Circ-0000979 promotes the development of gastric carcinoma by sponging miR-136 and modulating SP1 mRNA expression level.

Circular RNAs (circRNAs) are a new class of non-coding RNAs that play pivotal biological roles in several types of cancer cells. However, the role of circ-0000979 in gastric cancer (GC) has never been explored. Therefore, the current study aims to examine the functional effects of circ-0000979 in GC development and progression. The expression level of circ-0000979 was validated using qRT-PCR analysis. We found that circ-0000979 is significantly upregulated in GC samples. Using AGS and HGC27 GC cell line, we examined the biological functions and regulatory mechanisms of circ-0000979 in GC in vitro and in vivo by knocking down circ-0000979. We found that circ-0000979 is sub-cellularly localized in the cytoplasm of GC cells. Functionally, silencing circ-0000979 leads to a significant reduction in GC cell proliferation and migration. In vivo assays showed that circ-0000979 knockdown markedly reduced GC tumor growth. CircRNA interactome predicted miR-136 as circ-0000979 targeting miRNA, while starbase prediction result showed that miR-136 targeted the 3'UTR region of SP1 mRNA. Taken together, our results demonstrated that circ-0000979, as a carcinogenic circRNA, promotes the progression of GC by regulating the miR-136/SP1 pathway. Circ-0000979 is a potential RNA-based therapeutic target for GC treatment.