Biotherapy Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, Henan, China.
Department of Hematology, The Affiliated Cancer Hospital of Zhengzhou University, Zhengzhou, 450008, Henan, China.
Biomed Pharmacother. 2019 Apr;112:108632. doi: 10.1016/j.biopha.2019.108632. Epub 2019 Feb 20.
Cancer testis (CT) antigens are expressed in various types of tumors and represent the potential targets for T cell-based immunotherapy. Analysis of CT gene expression and DNA methylation have indicated that certain CT genes are epigenetically regulated and studies have confirmed that certain CT antigens are regulated by DNA methylation. In this study, we explored the epigenetic regulation of MAGE-A3 and improved the clinical outcome of MAGE-A3-specific T cell therapy in esophageal squamous cell carcinoma (ESCC). We used molecular profiling datasets in The Cancer Genome Atlas to analyze CT gene expression in ESCC and its regulation by DNA methylation. We performed quantitative reverse transcription PCR (qRT-PCR), immunohistochemistry and bisulfite sequencing in ESCC cell lines and ESCC tissues. Functional assays, such as flow cytometry, cytotoxicity assays and ELISA, were performed to determine the demethylation agent, decitabine (5-aza-2'-deoxycytidine, DAC)-treated cancer cell improved antigen specific T cells response. ESCC tumor cell-xenograft mouse model and enzyme-linked immunospot (ELISPOT) assays were used to determine the function of DAC treatment in enhancing anti-MAGE-3 T cell responses in ESCC. Furthermore, we performed qRT-PCR and flow cytometry in the peripheral blood mononuclear cells (PBMC) of myelodysplastic syndromes (MDS) patients. MAGE-A3, one of the CT antigens, expressed at various levels in ESCC and was interfered by DNA methylation. We observed an efficient increase in MAGE-A3 expression in tumor cells and tissues after the treatment of decitabine and the expression of MAGE-A3 was affected by DNA methylation. Functional assays showed enhanced secretion of IFN-γ and cytolysis of MAGE-A3 antigen-specific T cells by DAC-treated target cells. In the tumor cell-xenograft mouse model and ELISPOT assays, DAC increased the expression of MAGE-A3 and T cell mediated tumor clearance in ESCC as well. Notably, the proportions of MAGE-A3-responsive T cells were elevated in DAC-treated patients with MDS, indicating DAC dismissed the epigenetic inhibition of MAGE-A3. DAC would probably improve the clinical outcome of MAGE-A3-specific T cell therapy by augmenting the expression of target gene.
癌症睾丸抗原（CT）在各种类型的肿瘤中表达，代表了基于 T 细胞的免疫治疗的潜在靶点。CT 基因表达和 DNA 甲基化分析表明，某些 CT 基因受到表观遗传调控，研究证实某些 CT 抗原受 DNA 甲基化调控。在这项研究中，我们探讨了 MAGE-A3 的表观遗传调控，并提高了 MAGE-A3 特异性 T 细胞治疗在食管鳞状细胞癌（ESCC）中的临床疗效。我们使用癌症基因组图谱中的分子谱数据集分析 ESCC 中的 CT 基因表达及其受 DNA 甲基化的调控。我们在 ESCC 细胞系和 ESCC 组织中进行了定量逆转录 PCR（qRT-PCR）、免疫组织化学和亚硫酸氢盐测序。流式细胞术、细胞毒性测定和 ELISA 等功能测定用于确定去甲基化剂地西他滨（5-氮杂-2'-脱氧胞苷，DAC）处理后的癌细胞改善了抗原特异性 T 细胞的反应。ESCC 肿瘤细胞异种移植小鼠模型和酶联免疫斑点（ELISPOT）测定用于确定 DAC 处理在增强 ESCC 中抗-MAGE-3 T 细胞反应中的作用。此外，我们对骨髓增生异常综合征（MDS）患者的外周血单个核细胞（PBMC）进行了 qRT-PCR 和流式细胞术检测。MAGE-A3 是 CT 抗原之一，在 ESCC 中表达水平不同，并受到 DNA 甲基化的干扰。我们观察到地西他滨治疗后肿瘤细胞和组织中 MAGE-A3 表达的有效增加，并且 MAGE-A3 的表达受到 DNA 甲基化的影响。功能测定显示 DAC 处理的靶细胞增强了 IFN-γ的分泌和 MAGE-A3 抗原特异性 T 细胞的细胞溶解。在肿瘤细胞异种移植小鼠模型和 ELISPOT 测定中，DAC 也增加了 ESCC 中 MAGE-A3 的表达和 T 细胞介导的肿瘤清除。值得注意的是，在接受地西他滨治疗的 MDS 患者中，MAGE-A3 反应性 T 细胞的比例升高，表明地西他滨消除了 MAGE-A3 的表观遗传抑制。DAC 通过增强靶基因的表达，可能会改善 MAGE-A3 特异性 T 细胞治疗的临床疗效。
