The Effect Of Circ RNA Circ-CEP85l On Proliferation、Invasion And Migration Of Gastric Cancer And Its Mechanism

Background: Gastric cancer(GC)is one of the most common cancers in East Asia,including China,and the third leading cause of death from tumors in the world.As a circular structure without a 5 ’end cap and a 3’ end ploy(A)tail,circular RNA(circRNA)has better conservation and stability.More and more studies show that circRNA is involved in the development and progression of a variety of cancers.However,the role of circRNA in gastric cancer has not been fully elucidated.Therefore,investigating the role and mechanism of circRNA in the occurrence and development of gastric cancer will help early diagnosis of gastric cancer and provide new ideas for clinical treatment and prognosis of gastric cancer.Objective: 1.To investigate the expression of circ-CEP85 L in gastric cancer tissue and its effect on the proliferation,invasion and migration of gastric cancer cells.2.To explore the mechanism of circ-CEP85 L regulating gastric cancer development.Methods: 1.circRNA expression profile chip detected circRNAs differentially expressed in 5 cases of gastric adenocarcinoma tissues compared with adjacent tissues.2.Real-time fluorescence quantitative PCR(q RT-PCR)was used to verify the expression of differentially expressed circRNAs in gastric cancer tissues and corresponding adjacent tissues.3.To verify the tolerance of circ-CEP85 L to it by Rnase R enzyme.5.Transiently transfect circ-CEP85 L overexpression or knockdown plasmids in gastric cancer cell lines(MGC-803,AGS)to construct circ-CEP85 L overexpression and knock down gastric cancer cells.4.The effects of circCEP85 L on the proliferation,invasion and migration of gastric cancer cells were detect by CCK8,wound Healing,Colony-forming assay and transwell.5.cancer xenograft model in nude mice and optical in vivo imaging to verify the effect of circ-CEP85 L on gastric cancer cells in vivo.6.The double luciferase report experiment verifies whether circ-CEP85 L bind to miR-942-5p and miR-942-5p bind to NFKBIA.7.Fluorescence in situ hybridization experiment(FISH)to verify the localization of circ-CEP85 L and miR-942-5p in cells.8.recovery experiments verified the interrelationship of circCEP85 L,miR-942-5p,and NFKBIA.Result: 1.The circular RNA circ-CEP85 L is downregulate in gastric cancer tissues compared with adjacent tissues.2.Overexpressing circ-CEP85 L in gastric cancer cells(MGC-803),inhibiting the proliferation,invasion and migration of gastric cancer,knocking down circ-CEP85 L in gastric cancer cells(AGS)has the opposite effect.3.In vivo imaging: Nude mice were injected intraperitoneally with overexpressing circ-CEP85 L gastric cancer cells MGC-803 group,the fluorescence value was lower than that of the control group.4.circ-CEP85 L and miR-942-5p are co-localized in the cytoplasm,and circ-CEP85 L and miR-942-5p,miR-942-5p and NFKBIA are combined with each other.5.miR-942-5p can block the suppression of circCEP85 L on the proliferation,invasion and migration of gastric cancer cells.6.miR-942-5p can inhibit the formation of NFKBIA protein.7.circ-CEP85 L promotes NFKBIA protein expression through miR-942-5p.Conclusion: 1.Circular RNA circ-CEP85 L is lowly expressed in gastric cancer tissues compare with adjacent tissues,and circ-CEP85 L inhibits the proliferation,invasion and migration of gastric cancer.2.Circular RNA circ-CEP85 L inhibits the binding and degradation of NFKBIA m RNA by miR-942-5p through endogenous competitive binding,which promotes the translation of NFKBIA protein and further inhibits the development of gastric cancer.