乏氧条件下HIF-1α通过上调PD-L1促进鼻咽癌恶性发展的机制  

Mechanism of HIF-1αPromoting Malignant Development of Nasopharyngeal Carcinoma by Upregulating PD-L1 Under Hypoxic Conditions

作　　者：蒋豆豆 董佳文 胡德胜 周亚娟 JIANG Doudou;DONG Jiawen;HU Desheng;ZHOU Yajuan(College of Life Science and Technology,Huazhong Agricultural University,Wuhan 430079,China;Department of Radiotherapy,Hubei Cancer Hospital,Tongji Medical College,Huazhong University of Science and Technolgy,Wuhan 430079,China)

机构地区：[1]华中农业大学生命科学技术学院,武汉430079 [2]湖北省肿瘤医院(华中科技大学同济医学院附属湖北肿瘤医院)放疗中心,武汉430079

出　　处：《肿瘤防治研究》2021年第6期570-575,共6页Cancer Research on Prevention and Treatment

基　　金：国家自然科学基金(81803065)。

摘　　要：目的探讨乏氧条件下HIF-1α通过上调PD-L1促进鼻咽癌恶性发展的机制。方法选取人类鼻咽癌细胞系CNE2细胞进行实验。设置常氧组(20%O_(2))、乏氧组(1%O_(2))、HIF-1α-siRNA+乏氧组和NCsiRNA+乏氧组。MTT实验检测各组细胞增殖率;流式细胞术检测各组细胞凋亡;RT-PCR检测各组细胞中HIF-1α、STAT3和PD-L1 mRNA表达的变化;Western blot检测不同处理条件下各组细胞HIF-1α、STAT3和PD-L1蛋白表达的变化及STAT3磷酸化情况。结果MTT实验显示,乏氧组和转染细胞增殖率显著高于常氧组(P=0.000),HIF-1α-siRNA+乏氧组的细胞增殖率明显低于常氧组、乏氧组和NC-siRNA+乏氧组(P=0.000)。流式分析显示,HIF-1α-siRNA+乏氧组的细胞凋亡率显著高于其他三组(P=0.001)。RT-PCR检测显示,HIF-1α-siRNA+乏氧组的HIF-1α、PD-L1和STAT3 mRNA水平显著低于乏氧组和NC-siRNA+乏氧组。蛋白印迹结果显示,HIF-1α、PD-L1和STAT3蛋白表达趋势与mRNA分子水平趋势一致。HIF-1α-siRNA+乏氧组pSTAT3蛋白水平也显著低于乏氧组和NC-siRNA+乏氧组(P=0.001)。结论乏氧微环境下HIF-1α有可能通过STAT3上调PD-L1表达,进而促进癌细胞免疫逃逸,导致鼻咽癌恶性发展。Objective To explore the mechanism of HIF-1αpromoting malignant development of nasopharyngeal carcinoma by upregulating PD-L1 expression under hypoxic conditions.Methods CNE2 cells were divided into normoxia(20%O_(2)),hypoxia(1%O_(2)),HIF-1α-siRNA+hypoxia and NC-siRNA+hypoxia groups.Cell proliferation,apoptosis,the mRNA levels of HIF-1α,STAT3 and PD-L1,the protein levels of HIF-1α,PD-L1,STAT3 and STAT3 phosphorylation were detected by MTT assay,flow cytometry,RTPCR and Western blot,respectively.Results Cell proliferation of hypoxia group was significantly higher than that of normoxia group(P=0.000).The cell proliferation rate of HIF-1α-siRNA+hypoxia group was significantly lower than those in other groups(P=0.000).The apoptosis rate of HIF-1α-siRNA+hypoxia group was remarkably higher than those in other groups(P=0.001).RT-PCR detection showed that the mRNA levels of HIF-1α,PD-L1 and STAT3 in the HIF-1α-siRNA+hypoxia group were significantly lower than those in hypoxia group and NC-siRNA+hypoxia group.The protein expression of HIF-1α,PD-L1 and STAT3 showed similar tendency in Western blot assays compared with the mRNA levels.The pSTAT3 protein expression level in HIF-1α-siRNA+hypoxia group was significantly lower than those in hypoxia group and HIF-1α-siRNA+hypoxia group(P=0.001).Conclusion Under hypoxic microenvironment,HIF-1αmay up-regulate the expression of PD-L1 through STAT3,thereby promoting the immune escape of cancer cells,leading to the malignant development of nasopharyngeal carcinoma.

关 键 词：PD-L1 HIF-1Α 鼻咽癌 乏氧 

分 类 号：R739.62[医药卫生—肿瘤]