下调USP37抑制PD-L1表达增强三阴性乳腺癌细胞免疫反应  

Reducing USP37 enhances immune responses by inhibiting PD-L1 expression in triple-negative breast cancer cells MDA-MB-231

作　　者：杨慧媛 徐世圣 秦涛 王海宁 周宓 YANG Huiyuan;XU Shisheng;QIN Tao;WANG Haining;ZHOU Mi(Department of Oncology,Qingdao Municipal Hospital Affiliated to Qingdao University/Qingdao Municipal Hospital,Qingdao 266071,China;Department of Oncology,Navy 971 Hospital of the People's Liberation Army,Qingdao 266071,China)

机构地区：[1]青岛大学附属青岛市市立医院/青岛市市立医院肿瘤科,山东青岛266071 [2]中国人民解放军海军第九七一医院肿瘤科,山东青岛266071

出　　处：《现代医学》2024年第12期1863-1869,共7页Modern Medical Journal

基　　金：山东省自然科学基金资助项目(ZR2022QH055)。

摘　　要：目的:探讨下调USP37表达对三阴性乳腺癌(TNBC)细胞程序性死亡受体配体1(PD-L1)表达量的影响及对其抗肿瘤免疫反应的作用。方法:应用免疫组织化学染色法检测TNBC组织中USP37的表达量及其与PD-L1表达量之间的相关性。反用siRNA瞬时转染技术降低人TNBC细胞系MDA-MB-231细胞中USP37的表达。采用实时定量聚合酶链反应(qRT-PCR)、蛋白质印迹法(Western Blot)检测瞬时转染后MDA-MB-231细胞中USP37和PD-L1的mRNA及蛋白质的表达水平。将瞬时转染后的MDA-MB-231细胞与外周血单个核细胞(PBMC)进行共培养,采用CCK8法评估PBMC对MDA-MB-231细胞的杀伤作用,流式细胞术检测MDA-MB-231细胞中PD-L1的表达变化。结果:免疫组化结果显示,TNBC中USP37高表达且与PD-L1的表达量呈正相关(P<0.01)。与转染对照组相比,下调USP37后MDA-MB-231细胞中USP37和PD-L1的mRNA、蛋白质表达量均显著降低。CCK8实验显示,下调USP37增强PBMC对MDA-MB-231细胞的杀伤能力(P<0.01);流式细胞术显示,下调USP37 MDA-MB-231细胞表面PD-L1表达量下调(P<0.01)。结论:下调USP37可抑制MDA-MB-231细胞PD-L1的表达,影响TNBC的抗肿瘤免疫反应。Objective:To investigate the effect of downregulating USP37 expression on programmed death-ligand 1(PD-L1)expression in triple-negative breast cancer(TNBC)cells and its role in tumor immune response.Methods:Immunohistochemistry was used to detect the expression of USP37 and its correlation with PD-L1 expression in TNBC tissues.siRNA-mediated transient transfection was performed to downregulate USP37 expression in MDA-MB-231 cells.qRT-PCR and Western Blot were used to measure the mRNA and protein levels of USP37 and PD-L1 in MDA-MB-231 cells after transient transfection.MDA-MB-231 cells transfected with siRNA were co-cultured with peripheral blood mononuclear cells(PBMCs),and CCK8 assay was used to evaluate the cytotoxic effect of PBMCs on MDA-MB-231 cells.Flow cytometry was used to detect changes in PD-L1 expression on MDA-MB-231 cells.Results:Immunohistochemistry showed that USP37 was highly expressed in TNBC tissues and positively correlated with PD-L1 expression(P<0.01).Compared to the control group,downregulation of USP37 significantly reduced the mRNA and protein levels of both USP37 and PD-L1 in MDA-MB-231 cells.CCK8 assay indicated that downregulation of USP37 enhanced PBMC-mediated cytotoxicity against MDA-MB-231 cells(P<0.01).Flow cytometry showed that the expression of PD-L1 on the surface of MDA-MB-231 cells was significantly reduced in the USP37 downregulation group(P<0.01).Conclusion:Downregulation of USP37 inhibits PD-L1 expression on MDA-MB-231 cells and influences the anti-tumor immune response in TNBC.

关 键 词：三阴性乳腺癌 USP37 程序性死亡受体配体1 抗肿瘤免疫反应 

分 类 号：R737.9[医药卫生—肿瘤]