Jia Long, Xi Qing, Wang Huafeng, Zhang Zimu, Liu Hongkun, Cheng Yingnan, Guo Xiangdong, Zhang Jieyou, Zhang Qi, Zhang Lijuan, Xue Zhenyi, Li Yan, Da Yurong, Zhao Peng, Zhang Rongxin
Laboratory of Immunology and Inflammation, Department of Immunology, Key Laboratory of Immune Microenvironment and Diseases of Educational Ministry of China, Tianjin Medical University, Tianjin, China.
School of Life Science, Shanxi Normal University, Linfen, China.
Biochem Biophys Res Commun. 2017 Jun 24;488(2):425-431. doi: 10.1016/j.bbrc.2017.05.074. Epub 2017 May 13.
Cancer immunotherapy has many great achievements in recent years. One of the most promising cancer immunotherapies is PD-1/PD-L1 pathway blockade. miRNAs (MicroRNAs) belongs to small noncoding RNA and can regulate gene expression by binding to the 3'UTR. Many miRNAs can inhibit cancer growth by regulating the PD-L1 expression in cancer cells. Herein, we firstly found that PD-L1 could be the target of miR-142-5p by using bioinformatics methods, then we conduct luciferase activity assay, RT-PCR and western blot experiments to demonstrate that miR-142-5p can regulate PD-L1 expression by binding to its 3'UTR. And in vivo experiments certified that miR-142-5p overexpression can inhibit pancreatic cancer growth. Flow cytometry and RT-PCR experiment demonstrated that miR-142-5p overexpression on tumor cells inhibits the expression of PD-L1 on tumor cells which result in the increase of CD4 T lymphocytes and CD8 T lymphocytes, the decrease of PD-1 T lymphocytes and increase of IFN-γ and TNF-α. So, miR-142-5p overexpression can enhance anti-tumor immunity by blocking PD-L1/PD-1 pathway. Our results identify a novel mechanism by which PD-L1 is regulated by miR-142-5p and overexpression of miR-142-5p could enhance the anti-tumor immunity.
近年来，癌症免疫疗法取得了诸多重大成就。最具前景的癌症免疫疗法之一是PD-1/PD-L1通路阻断。微小RNA（miRNAs）属于小非编码RNA，可通过与3'非翻译区（3'UTR）结合来调节基因表达。许多微小RNA可通过调节癌细胞中PD-L1的表达来抑制癌症生长。在此，我们首先利用生物信息学方法发现PD-L1可能是miR-142-5p的靶标，然后进行荧光素酶活性测定、逆转录聚合酶链反应（RT-PCR）和蛋白质免疫印迹实验，以证明miR-142-5p可通过与PD-L1的3'UTR结合来调节其表达。体内实验证实，miR-142-5p过表达可抑制胰腺癌生长。流式细胞术和RT-PCR实验表明，肿瘤细胞上过表达miR-142-5p可抑制肿瘤细胞上PD-L1的表达，从而导致CD4 T淋巴细胞和CD8 T淋巴细胞增加，PD-1 T淋巴细胞减少，以及γ干扰素（IFN-γ）和肿瘤坏死因子-α（TNF-α）增加。因此，miR-142-5p过表达可通过阻断PD-L1/PD-1通路增强抗肿瘤免疫力。我们的研究结果确定了一种新的机制，即miR-142-5p调节PD-L1，且miR-142-5p过表达可增强抗肿瘤免疫力。
