Ye Zi-Han, Jiang Xiao-Ming, Huang Mu-Yang, Xu Yu-Lian, Chen Yu-Chi, Yuan Luo-Wei, Huang Can-Yu, Yu Wei-Bang, Chen Xiuping, Lu Jin-Jian
State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.
State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China; MoE Frontiers Science Center for Precision Oncology, University of Macau, Macao, China.
Transl Oncol. 2021 Sep;14(9):101162. doi: 10.1016/j.tranon.2021.101162. Epub 2021 Jun 23.
The anti-phagocytosis signal, CD47, prevents phagocytosis when it interacts with signal-regulatory protein alpha (SIRPα) on macrophages. Given the vital role of CD47 in immune response, further investigation on the regulation of CD47 in tumor microenvironment is needed. Herein, we identified that interferon-gamma (IFN-γ), one of the most important cytokines in the immune and inflammatory response, up-regulated CD47 expression in cancer cells and this effect could be inhibited by the JAK1/2 inhibitor ruxolitinib, as well as siRNA-mediated silencing of JAK1, STAT1, and IRF1. The IFN-γ-induced surface expression of CD47 contributed to a stronger binding affinity to SIRPα and a decrease in phagocytosis of cancer cells by macrophages. Knockdown of JAK1, STAT1, or IRF1 by siRNA reversed the decreased phagocytosis caused by IFN-γ. Besides, analysis from TCGA revealed that IFNG had a positive correlation with CD47 in various types of cancer, which was supported by the increased surface CD47 expression after IFN-γ treatment in different types of cancer cells. The discovery of IFN-γ-induced up-regulation of CD47 in cancer cells unveils another feedback inhibitory mechanism of IFN-γ, thus providing insights into cancer immunotherapy targeting CD47.
抗吞噬信号分子CD47与巨噬细胞上的信号调节蛋白α(SIRPα)相互作用时可阻止吞噬作用。鉴于CD47在免疫反应中的重要作用,有必要进一步研究肿瘤微环境中CD47的调控机制。在此,我们发现免疫和炎症反应中最重要的细胞因子之一——干扰素-γ(IFN-γ)可上调癌细胞中CD47的表达,而JAK1/2抑制剂鲁索替尼以及JAK1、STAT1和IRF1的siRNA介导沉默可抑制这种作用。IFN-γ诱导的CD47表面表达导致其与SIRPα的结合亲和力增强,巨噬细胞对癌细胞的吞噬作用降低。通过siRNA敲低JAK1、STAT1或IRF1可逆转IFN-γ引起的吞噬作用降低。此外,来自癌症基因组图谱(TCGA)的分析显示,IFNG在各种类型癌症中与CD47呈正相关,不同类型癌细胞经IFN-γ处理后表面CD47表达增加也支持了这一点。IFN-γ诱导癌细胞中CD47上调这一发现揭示了IFN-γ的另一种反馈抑制机制,从而为靶向CD47的癌症免疫治疗提供了思路。