Effects Of Circular RNA Circ-Foxo3 On Proliferation?Apoptosis And Radiosensitivity Of Esophageal Squamous Cell Cancer

Objective: Observe the expression level and significance of circ-Foxo3 in esophageal squamous cell cancer(ESCC)and explore its effects on ESCC cell proliferation,apoptosis,radiosensitivity.Methods: q RT-PCR was used to detect the expression of circ-Foxo3 in ESCC tissues and adjacent normal tissues,as well as ESCC cell lines.Two cell lines(ECA109 and TE-13)were selected to be divided into two groups for cell experiments,circ-Foxo3 overexpression group and NC group.CCK8,Ed U and colony formation experiments were used to detect the impact of circ-Foxo3 on esophageal squamous cancer cells proliferation activity,and the effect of circ-Foxo3 on cell cycle was detected by cell cycle assay.After X-ray treatment,the two groups were tested by Annexin V/PI flow cytometry and Hoechst33258 experiments to detect the effect of circ-Foxo3 on apoptosis of cells;cell survival experiments detect the effect of circ-Foxo3 on the radiation sensitivity of ESCC and to plot the cell survival curves by single-hit multitarget model.Using bioinformatics to predict circ-Foxo3 possible target mi RNA(mi R-23a)and downstream target gene PTEN.The effect of circ-Foxo3 on PTEN protein expression was detected by the western blot assay and grayscale analysis.Finally,the experiment of xenografted tumor was carried out with the transfected ECA109 cells,which further confirmed the effect of circ-Foxo3 on the proliferation of ESCC.Results: circ-Foxo3 was low expression in ESCC tissues and cell lines(P<0.05);circFoxo3 has an inhibitory effect on the proliferation of ESCC cells(P<0.05);circFoxo3 induced G0/G1 cell cycle arrest(P<0.05).At the same dose of X-ray exposure,in the Annexin V/PI flow cytometry and Hoechst33258 experiments,the number of apoptosis cells in the circ-Foxo3 overexpression group was higher than in the NC group(P<0.05);the cell survival curve of circ-Foxo3 overexpression group were significantly lower than NC group(P<0.05);The western blot assay shown that the overexpression of circ-Foxo3 could increase the expression level of PTEN.In vivo,tumors in circ-Foxo3 overexpression group were smaller than NC group,immune histology analysis found that the level expression of PTEN in circ-Foxo3 overexpression group was higher than NC group.Conclusion: circ-Foxo3 is a new type of tumor inhibitor that inhibits ESCC proliferation and increases its radiosensitivity,the mechanism is that circ-Foxo3 arrest cells in G0/G1 phase by regulating mi R-23a/PTEN network.