［Abstract］Objective: To investigate the expression level and clinical value of hsa_circ_0079557 in gastric cancer.Methods: Five pairs of gastric cancer tissues and adjacent tissues were collected and detected by high-throughput sequencing technology, combined with the data of gastric cancer in circbase and other databases, to screen for differentially expressed circRNAs.In 62 pairs of samples, hsa_circ_0079557 was detected by qRT-PCR, and its relationship with clinicopathological characteristics was analyzed.The expression levels of hsa_circ_0079557 in gastric cancer cells and gastric mucosal epithelial cells, preoperative and postoperative serums of gastric cancer patients, and serums of gastric cancer patients and healthy people were detected.After hsa_circ_0079557 was knocked down by siRNA, cell clone formation assay, plate scratch assay, and cell cycle flow cytometry assay were used to detect the changes in cell cloning, migration and cell cycle of gastric cancer cells, respectively.Western blotting was used to determine cyclin dependent kinase 3 （CDK3） expression level.Results: The expression level of hsa_circ_0079557 in human gastric cancer tissues was significantly higher than that in adjacent tissues（P<0.05）, and its expression level was related to the tumor TMN stage（P<0.05）; the expression level of hsa_circ_0079557 in gastric cancer cells was significantly higher than that in human gastric mucosal epithelial cells（P<0.05）; the expression level of hsa_circ_0079557 in serum of gastric cancer patients before operation was significantly higher than that after operation （P<0.01）; hsa_circ_0079557 knockdown in gastric cancer cell lines resulted in decreased proliferation and migration ability of some gastric cancer cells and decreased CDK3 expression level（P<0.05）.In gastric cancer cell lines, hsa_circ_0079557 knockdown resulted in cell arrest in G0-G1 phase.Conclusion: Hsa_circ_0079557 is highly expressed in gastric cancer tissues, which might be used as a potential biomarker for early diagnosis and prognosis of gastric cancer.
