低氧微环境对三阴性乳腺癌程序性死亡因子配体1表达和肿瘤免疫的调控  

Regulation of hypoxia microenvironment on programmed death ligand 1 expression and immune response in triple negative breast cancer

作　　者：钱学珂[1] 叶润仪[1] 邵楠[1] 史雅薇 张晋[1] 王深明[1] 林颖[1] 

机构地区：[1]中山大学附属第一医院甲状腺乳腺外科,广州510080

出　　处：《中华实验外科杂志》2017年第4期544-547,共4页Chinese Journal of Experimental Surgery

基　　金：广东省科技计划项目（20138021800260、20138060300005）

摘　　要：目的观察肿瘤微环境中氧含量对三阴性乳腺癌（TNBC）程序性死亡因子配体1（PD-L1）表达和肿瘤免疫的调控。方法将1×105个4T1细胞接种至雌性BALB/c小鼠乳腺脂肪垫，28 d后验证TNBC肺转移小鼠模型建立成功。采用流式细胞术比较体外培养4T1细胞和28 d体内4T1细胞表面的PD-L1表达，并比较28 d转移肺与正常肺组织的CD4＋、CD8＋T淋巴细胞和总淋巴细胞比例。采用低氧探针Hypoxyprobe-1和免疫组织化学方法，明确肿瘤组织中的低氧区域。免疫荧光双标记染色法检测Hypoxyprobe-1阳性反应信号为绿色荧光，PD-L1阳性反应信号为红色荧光，两者重叠为黄色荧光。 结果4T1小鼠肺转移模型中，原发灶内细胞PD-L1表达水平较体外培养细胞明显升高（32.55%比3.87%，P＝0.000）；原发肿瘤和转移肺组织中存在不同程度的深层低氧区，高表达PD-L1细胞集中于肿瘤低氧区域；28 d的荷瘤小鼠肺部T细胞、CD4＋ T细胞、CD8＋ T细胞占总白细胞比例较正常小鼠肺明显减少，分别为1.72%比19.61%，P＝0.000；1.15%比15.67%，P＝0.000；0.29%比3.20%，P＝0.001。CD4＋ T细胞、CD8＋ T细胞占总T细胞比例也较正常小鼠肺明显减少，分别为66.56%比79.94%，P＝0.006；16.81%比28.93%，P＝0.000。结论肿瘤低氧微环境与TNBC肿瘤细胞PD-L1表达升高相关，通过此机制参与了肿瘤T细胞免疫抑制的调节。Objective To investigate tile regulation of hypoxia microenvironment on the programmed death ligand l （PD -L1 ） expression and immune response in triple negative breast cancer （TNBC）. Methods 1 x 10~ 4TI cells were injected subcutaneously into abdominal mammary gland of female BALB/c mice to estab- lish a mouse model of TNBC lung metastasis after 28 days. The PD - L1 expression detected by flow cytome- try was compared between 4T1 cells in vivo and in vitro, and the proportion of CD4＋ , CD8＋ and T lympho- cyte subsets were compared between lungs of 28 - day 4T1 - bearing mice and normal mice. Hypoxia zones in the microenvironment of tumor were determined using Hypoxyprobe - 1 and immunohistochemistry. Double - stained immunofluorescence was applied to observe the connection between PD - L1 protein and Hypoxyprobe - 1. Results The expression of PD - L1 on 4T1 could hardly be detected in vitro and a sig- nificant increase was observed in vivo （ 32. 55% vs. 3.87% , P = 0. 000 ）. Increased hypoxia levels in tumor and lung microenvironments of 28 - day 4T1 mice were observed, and tumor and lung tissue hypoxia could recruit PD - L1 expression cells. Lungs from 28 - day 4T1 mice developed a significant decrease of the proportion of CD4＋ T cells, CD8＋ T cells and total T cells when compared with lungs from normal mice. Conclusion Hypoxia microenvironment may induce PD - L1 expression and regulate immune re- sponse in TNBC.

关 键 词：{阴性乳腺癌 缺氧 程序性死亡因子配体1 转移 肿瘤免疫 

分 类 号：R737.9[医药卫生—肿瘤]