APE1通过免疫抑制性肿瘤微环境介导结肠炎相关结直肠癌的发生发展  

APE1 mediates the occurrence and development of colitis-associated colorectal cancer through immunosuppressive tumor microenvironment

作　　者：陈天一 李超凡 包灵波 陈骞 胡那娜 杨宇馨 张蕾 王东 CHEN Tianyi;LI Chaofan;BAO Lingbo;CHEN Qian;HU Nana;YANG Yuxin;ZHANG Lei;WANG Dong(Cancer Center,Army Medical Center of PLA,Chongqing,400042;Yu-Yue Pathology Scientific Research Center,Chongqing,400039;Jinfeng Laboratory,Chongqing,401329,China)

机构地区：[1]陆军特色医学中心肿瘤中心,重庆400042 [2]渝粤病理科学研究中心,重庆400039 [3]金凤实验室,重庆401329

出　　处：《陆军军医大学学报》2024年第16期1825-1837,共13页Journal of Army Medical University

基　　金：国家自然科学基金面上项目(82073170)。

摘　　要：目的探讨脱嘌呤/脱嘧啶核酸内切酶1(apurinic/apyrimidinic endonuclease 1,APE1)在慢性肠道炎症向结肠炎相关性结直肠癌(colitis-associated colorectal cancer,CAC)转化过程中的调控机制。方法将C64S点突变纯合子(APE1^(C64S))和野生型(APE1^(WT))小鼠分别按随机数字表法分为实验组与对照组,实验组应用氧化偶氮甲烷(azoxymethane,AOM)及葡聚糖硫酸钠盐(dextran sulfate sodium salt,DSS)溶液构建CAC体内模型,采用免疫组化及多重免疫荧光分析各组小鼠结肠组织APE1表达及免疫细胞浸润情况。通过慢病毒转染构建APE1稳定敲低的小鼠结肠癌MC38细胞系,并对APE1^(WT)与APE1^(C64S)小鼠进行皮下荷瘤实验以确定肿瘤细胞来源的APE1导致免疫抑制性肿瘤微环境,采用免疫组化及多重免疫荧光分析荷瘤标本APE1、趋化因子(C-X-C基序)配体1[chemokine(C-X-C motif)ligand 1,CXCL1]表达及免疫细胞浸润情况。对来自陆军特色医学中心的1名28岁女性CAC患者的肿瘤标本采用免疫组化及多重免疫荧光分析肿瘤及邻近炎症组织中APE1、CXCL1的表达及免疫细胞浸润情况。结果与对照组及APE1^(WT)实验组相比,APE1^(C64S)实验组小鼠的疾病活动指数及肿瘤形成数量明显降低,多形核髓源抑制细胞(polymorphonuclear myeloid-derived suppressor cells,PMN-MDSCs)浸润显著减少,CD4^(+)及CD8^(+)T细胞显著增多(P<0.05)。APE1^(WT)与APE1^(C64S)皮下荷瘤小鼠肿瘤生长及各免疫细胞差异无统计学意义;而使用敲低APE1的肿瘤细胞进行荷瘤实验,发现肿瘤生长明显抑制,PMN-MDSCs浸润减少,同时CD4^(+)及CD8^(+)T细胞显著增多(P<0.05)。在CAC患者肿瘤组织中APE1高表达、PMN-MDSCs浸润增加,CD8^(+)T细胞在肿瘤组织中较炎症组织浸润显著减少(P<0.05)。结论肿瘤细胞中APE1的氧化还原功能可促进PMN-MDSCs肿瘤浸润,同时减少T细胞的数量,从而形成免疫抑制性肿瘤微环境介导CAC的发生发展。Objective To investigate the regulatory mechanism of apurnic/apyrimidinic endonuclease 1(APE1)in the transformation of chronic intestinal inflammation to colitis-associated colorectal cancer(CAC).Methods C64S mutant(APE1^(C64S))mice and APE1 wild type(APE1^(WT))mice were randomly divided into experimental group and control group.In vivo CAC model was established by azoxymethane(AOM)and dextran sulfate sodium salt(DSS)solution.Immunohistochemistry(IHC)and multiple IHC(mIHC)assays were used to observe the expression of APE1 and immune cell infiltration in colon tissues of each group.A mouse colon cancer cell line MC38 with stable knockdown of APE1 was constructed by lentivirus transfection,and subcutaneous tumor bearing experiments were performed in APE1^(WT)and APE1^(C64S)mice to confirm that tumor cell-derived APE1 caused immunosuppressive tumor microenvironment.The expression of APE1 and CXCL1[chemokine(C-X-C motif)ligand 1]and the infiltration of immune cells in tumor-bearing specimens were analyzed by IHC and mIHC assays.The tumor specimens of a 28-year-old female patient with CAC from Army Medical Center of PLA were analyzed for the expression of APE1 and CXCL1 and the infiltration of immune cells in the tumor and adjacent inflammatory tissues by IHC and mIHC assays.Results Compared with the control group and APE1^(WT)erperimental group,APE1^(C64S)erperimental group had significantly reduced disease activity index and tumor formation,polymorphonuclear myeloid-derived suppressor cells(PMN-MDSCs)infiltration,and CD4^(+)and CD8^(+)T cells(P<0.05).No significant differences were observed in tumor growth and immune cells between APE1^(WT)and APE1^(C64S)mice bearing subcutaneous tumors.However,in the tumor-bearing experiment using tumor cells with knockdown of APE1,the tumor growth was significantly lower and the number of infiltrated PMN-MDSCs was reduced,while those of CD4^(+)and CD8^(+)T cells were significantly increased(P<0.05).Furthermore,high expression of APE1 and increased infiltration of PMN-MDSCs were fo

关 键 词：结肠炎相关性结直肠癌 炎症性肠病 脱嘌呤/脱嘧啶核酸内切酶1 多形核髓源性抑制细胞 结直肠癌 肿瘤微环境 

分 类 号：R345[医药卫生—基础医学] R730.23R735.35