Department of Oncology, The Second Xiangya Hospital, Central South University, 410011, Changsha, Hunan Province, P.R. China.
Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 430022, Wuhan, P.R. China.
Cell Death Dis. 2020 Dec 2;11(12):1028. doi: 10.1038/s41419-020-03200-7.
Immune escape is an important mechanism in tumorigenesis. The aim of this study was to investigate roles of SKIL in tumorigenesis and immune escape of non-small-cell lung cancer (NSCLC). SKIL expression levels in NSCLC cell line, clinical sample, and adjacent normal tissue were measured by quantitative PCR, western blot, or immunohistochemistry. Lentivirus was used to overexpress/silence SKIL or TAZ expression. Malignant phenotypes of NSCLC cells were evaluated by colony formation, transwell, and MTT assays, and in xenograft mice model. Syngeneic mice model and flow cytometry were used to evaluate T cell infiltration. Quantitative PCR and western blot were applied to evaluate relevant mRNA and protein levels, respectively. Co-immunoprecipitation was applied to unveil the interaction between SKIL and TAZ. SKIL expression was higher in NSCLC tissue compared to adjacent normal tissue. Silencing of SKIL inhibited malignant phenotypes of NSCLC cells and promoted T cell infiltration. SKIL-knockdown inhibited autophagy and activated the STING pathway in NSCLC cells through down-regulation of TAZ. Silencing of TAZ cancelled the effects of SKIL overexpression on malignant phenotypes and autophagy of NSCLC cells. Inhibition of autophagy reversed the effects of SKIL/TAZ overexpression on the STING pathway. In conclusion, SKIL promoted tumorigenesis and immune escape of NSCLC cells through upregulation of TAZ/autophagy axis and inhibition on downstream STING pathway.
免疫逃逸是肿瘤发生的重要机制。本研究旨在探讨 SKIL 在非小细胞肺癌（NSCLC）发生和免疫逃逸中的作用。通过定量 PCR、western blot 或免疫组化检测 NSCLC 细胞系、临床样本和相邻正常组织中的 SKIL 表达水平。使用慢病毒过表达/沉默 SKIL 或 TAZ 的表达。通过集落形成、transwell 和 MTT 测定以及异种移植小鼠模型评估 NSCLC 细胞的恶性表型。利用同基因小鼠模型和流式细胞术评估 T 细胞浸润。应用定量 PCR 和 western blot 分别评估相关的 mRNA 和蛋白水平。应用免疫共沉淀揭示 SKIL 和 TAZ 之间的相互作用。与相邻正常组织相比，NSCLC 组织中 SKIL 表达水平更高。沉默 SKIL 抑制 NSCLC 细胞的恶性表型并促进 T 细胞浸润。SKIL 敲低通过下调 TAZ 抑制 NSCLC 细胞中的自噬并激活 STING 通路。沉默 TAZ 取消了 SKIL 过表达对 NSCLC 细胞恶性表型和自噬的影响。自噬抑制逆转了 SKIL/TAZ 过表达对 STING 通路的影响。总之，SKIL 通过上调 TAZ/自噬轴和抑制下游 STING 通路促进 NSCLC 细胞的肿瘤发生和免疫逃逸。
