Xiangya Cancer Center, Xiangya Hospital, Central South University, Changsha, Hunan, China; Key Laboratory of Molecular Radiation Oncology Hunan Province, Changsha, Hunan, China.
Department of Otolaryngology-Head Neck Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China.
Int J Radiat Oncol Biol Phys. 2020 Sep 1;108(1):126-139. doi: 10.1016/j.ijrobp.2020.05.001. Epub 2020 May 16.
Radiation therapy elicits profound alterations in gene expression in tumor cells. This study aims to determine the dynamic changes in the expression of immunity-associated genes in nasopharyngeal carcinoma (NPC) cells upon radiation therapy.
The study was performed using NPC patient-derived tumor xenograft tumors, cell lines, CCR4 CD8 T cells sorted from peripheral blood mononuclear cells of healthy volunteers, and TCGA-derived bulk RNA-seq or single-cell RNA-seq (scRNA-seq) data sets. Patient-derived tumor xenograft tumors or cell lines were irradiated and collected for bulk RNA sequencing or for CCL22 expression and release detection. Malignant phenotypes and radiosensitivity were assessed in cells with or without overexpression of CCL22 or recombinant CCL22 treatment in the presence or absence of irradiation. TCGA data sets were used for uncovering CCR4 status in subtypes of T cells. CCL22 in supernatants, cell lysates, or serum samples was measured with enzyme-linked immunosorbent assay.
CCL22 was significantly increased in the irradiated patient-derived tumor xenograft tumors, the supernatants and cell lysates collected from irradiated NPC cell lines, and the serum of patients who received radiation therapy. No alterations of malignant phenotypes were found in tumor cells with CCL22 overexpression or recombinant CCL22 treatment. Kaplan-Meier analysis revealed that CCL22 or its receptor CCR4 positively correlated with cytotoxic T lymphocyte signatures, and high expression of CCL22 or CCR4 was associated with better prognosis for patients with NPC. scRNA-seq data set-based analysis demonstrated that CCR4 was expressed in multiple subtypes of T cells, including effector CD8 T cells. Chemotaxis assay indicated that CCR4 CD8 T cells could be recruited by CCL22 treatment.
The radiation-enhanced release of CCL22 from NPC cells promotes migration of CCR4 effector CD8 T cells, which might partially be associated with radiation therapy-mediated antitumor immunity.
放射治疗会引起肿瘤细胞中基因表达的深刻改变。本研究旨在确定鼻咽癌（NPC）细胞在放射治疗后免疫相关基因表达的动态变化。
该研究使用 NPC 患者来源的肿瘤异种移植瘤、细胞系、从健康志愿者外周血单核细胞中分选的 CCR4 CD8 T 细胞，以及 TCGA 衍生的批量 RNA-seq 或单细胞 RNA-seq（scRNA-seq）数据集进行。对患者来源的肿瘤异种移植瘤或细胞系进行照射，并收集批量 RNA 测序或 CCL22 表达和释放检测。在有无照射的情况下，通过过表达 CCL22 或重组 CCL22 处理，评估细胞的恶性表型和放射敏感性。使用 TCGA 数据集揭示 T 细胞亚群中的 CCR4 状态。通过酶联免疫吸附试验测量上清液、细胞裂解物或血清样本中的 CCL22。
在照射的患者来源的肿瘤异种移植瘤、从照射的 NPC 细胞系收集的上清液和细胞裂解物以及接受放射治疗的患者的血清中，CCL22 明显增加。在过表达 CCL22 或重组 CCL22 处理的肿瘤细胞中，未发现恶性表型的改变。Kaplan-Meier 分析显示，CCL22 或其受体 CCR4 与细胞毒性 T 淋巴细胞特征呈正相关，CCL22 或 CCR4 的高表达与 NPC 患者的预后较好相关。基于 scRNA-seq 数据集的分析表明，CCR4 在包括效应 CD8 T 细胞在内的多种 T 细胞亚群中表达。趋化性测定表明，CCL22 处理可募集 CCR4 CD8 T 细胞。
NPC 细胞中放射增强的 CCL22 释放促进了 CCR4 效应 CD8 T 细胞的迁移，这可能与放射治疗介导的抗肿瘤免疫部分相关。
