Circ_0032821 Facilitates Gastric Cancer Cell Proliferation, Migration, Invasion and Glycolysis by Regulating MiR-1236-3p/HMGB1 Axis

Background: Circular RNAs (circRNAs) play an essential role in the pathogenesis of malignant tumors, including gastric cancer (GC). However, the effect of circ_0032821 on GC remains largely unknown. Methods: QRT-PCR assay was employed to examine the levels of circ_0032821, CEP128 mRNA and miR-1236-3p. RNase R digestion assay was utilized to verify the feature of circ_0032821. Cell Counting Kit-8 (CCK-8) assay and transwell assay were adopted to evaluate cell proliferation and metastasis. The level of glycolysis was evaluated through detecting ECAR, OCR, lactate production, glucose uptake and ATP synthesis. Dualluciferase reporter assay and RIP assay were conducted to analyze the relationship between miR-1236-3p and circ_0032821 or HMGB1. Western blot assay was adopted for high mobility group box 1 (HMGB1) level. Murine xenograft model assay was utilized for the effect of circ 0032821 in vivo. Results: High level of circ_0032821 was observed in GC tissues and cells. Silencing of circ_0032821 markedly repressed cell proliferation, metastasis and glycolysis in GC cells in vitro and blocked tumorigenesis of GC in vivo. For mechanism analysis, circ_0032821 was identified as the sponge of miR-1236-3p and HMGB1 was the target gene of miR-12363p. Moreover, miR-1236-3p suppression restored the influences of circ_0032821 deficiency on GC cell proliferation, metastasis and glycolysis. Overexpression of miR-1236-3p relieved the malignant behaviors of GC cells by targeting HMGB1. Conclusion: Circ_0032821 accelerated GC development through elevating HMGB1 expression via sponging miR-1236-3p.