Circ_0084927通过miR-623/EZH2轴调控乳腺癌免疫逃逸

Circ_0084927 regulates breast cancer immune escape via miR-623/EZH2 axis

目的探讨circ_0084927作为分子海绵吸附miR-623靶向调控EZH2基因对乳腺癌(breast cancer,BC)细胞免疫逃逸的影响。方法生物信息学网站预测circ_0084927/miR-623/EZH2调控轴并借助双荧光素酶报告试验进行验证。BC细胞与CD8+T细胞共培养,流式细胞术检测探测T细胞的凋亡情况和在共转染的微环境下的占比。结果与癌旁组织相比,BC患者组织样本中EZH2和circ_0084927的表达明显上调,而miR-623的表达减弱(P<0.05)。circ_0084927能作为BC的一个有效诊断指标(AUC=0.8138,P<0.0001)。与si-NC组的CD8+T细胞凋亡率(34.17±3.06)和细胞占比(26.55±2.83)比较,circ_0084927的抑制会造成CD8+T细胞凋亡率的下降(22.37±2.05),CD8+T细胞在共转染环境中的占比增高(31.88±3.03),但该效果可被过表达EZH2部分挽救。miR-623抑制CD8+T细胞凋亡,过表达circ_0084927减弱miR-623对免疫逃逸的抑制作用(均P<0.05)。结论circ_0084927调控miR-623/EZH2轴促进BC细胞免疫逃逸,提示靶向circ_0084927可能是提高BC免疫治疗疗效的一种潜在途径。

Objective To investigate the effect of circ_0084927 as a molecular sponge adsorbing miR-623 to target and regulate EZH2 gene on immune escape in breast cancer(BC)cells.Methods Bioinformatics websites were used to predict the circ_0084927/miR-623/EZH2 regulatory axis,which was then validated with the aid of dual luciferase reporter assay.BC cells were co-cultured with CD8+T cells and theflow cytometry assays were performed to detect apoptotic rate and the proportion of T cells in the co-transfected microenvironment.Results The expression level of EZH2 and circ_0084927 were significantly upregulated in BC patient tissue samples compared to paracancerous tissue,while miR-623 expression was dramatically diminished(P<0.05).circ_0084927 can be used as an effective diagnostic index of BC(AUC=0.8138,P<0.0001).Compared with apoptosis rate of CD8+T cells(34.17±3.06)and percentage of T cells(26.55±2.83),circ_0084927 inhibition caused a decrease in the apoptosis rate of CD8+T cells(22.37±2.05)and an increase in the proportion of CD8+T cells(31.88±3.03)in the co-transfected environment,but this effect was partiallycounteractedby overexpression of EZH2.miR-623 inhibited CD8+T cell apoptosis.Circ_0084927 attenuated the inhibitory effect of miR-623 on immune escape(both P<0.05).Conclusion circ_0084927 regulates the miR-623/EZH2 axis to promote immune escape of BC cells,suggesting targeting circ_0084927 may be a potential way to improve the efficacy of immunotherapy for BC.