长链非编码 RNA EGFR-AS1 通过 EGFR-MYC-PD-L1 轴促进平滑肌肉瘤的进展和免疫逃逸。

lncRNA EGFR-AS1 facilitates leiomyosarcoma progression and immune escape via the EGFR-MYC-PD-L1 axis.

机构信息

Biomedical Engineering College, Hubei University of Medicine, Shiyan 442000, Hubei Province, P.R. China.

Reproductive Medicine Center, Renmin Hospital, Hubei University of Medicine, Shiyan 442000, Hubei Province, P.R. China.

出版信息

Int Immunol. 2022 Jul 4;34(7):365-377. doi: 10.1093/intimm/dxac014.

DOI:10.1093/intimm/dxac014

PMID:35485964

Abstract

AIM

this study aimed to investigate the role of long non-coding RNA (lncRNA) epidermal growth factor receptor antisense RNA 1 (EGFR-AS1), an antisense transcript of EGFR, in leiomyosarcoma (LMS) and the underlying mechanisms.

METHODS

levels of EGFR-AS1 and programmed death ligand 1 (PD-L1) were measured in LMS tissues and cell lines using quantitative real-time PCR (qRT-PCR), as well as western blotting and/or immunohistochemical staining; flow cytometry was employed to validate the role of EGFR-AS1 in altering the activity of CD8+ T cells; interaction of EGFR-AS1 and EGFR was determined by fluorescent in situ hybridization (FISH) and RNA pull-down; regulation of MYC on the PD-L1 promoter was assessed by chromatin immunoprecipitation (ChIP); a xenograft in vivo tumor growth assay was applied to verify the EGFR-AS1/EGFR/MYC/PD-L1 axis in vivo.

RESULTS

up-regulation of EGFR-AS1 and PD-L1 in LMS tissues was negatively correlated with CD8+ T-cell infiltration; EGFR-AS1 positively regulated PD-L1, thereby strengthening interaction of LMS cells and CD8+ T cells and triggering CD8+ T cell apoptosis via the PD-1/PD-L1 checkpoint; EGFR-AS1 co-localized and interacted with EGFR to promote MYC activity; MYC was identified as a transcriptional activator of PD-L1.

CONCLUSION

lncRNA EGFR-AS1 was demonstrated to increase PD-L1 expression through the EGFR/MYC pathway in LMS cells, thereby repressing T-cell infiltration and contributing to immune escape.

摘要

目的

本研究旨在探讨长链非编码 RNA（lncRNA）表皮生长因子受体反义 RNA 1（EGFR-AS1）在平滑肌肉瘤（LMS）中的作用及其潜在机制。

方法

采用实时定量 PCR（qRT-PCR）、Western blot 及免疫组织化学染色检测 LMS 组织和细胞系中 EGFR-AS1 和程序性死亡配体 1（PD-L1）的水平；采用流式细胞术验证 EGFR-AS1 改变 CD8+T 细胞活性的作用；采用荧光原位杂交（FISH）和 RNA 下拉实验确定 EGFR-AS1 与 EGFR 的相互作用；采用染色质免疫沉淀（ChIP）检测 MYC 对 PD-L1 启动子的调控作用；采用体内异种移植肿瘤生长实验验证 EGFR-AS1/EGFR/MYC/PD-L1 轴在体内的作用。

结果

LMS 组织中 EGFR-AS1 和 PD-L1 的上调与 CD8+T 细胞浸润呈负相关；EGFR-AS1 正向调节 PD-L1，从而增强 LMS 细胞与 CD8+T 细胞的相互作用，通过 PD-1/PD-L1 检查点触发 CD8+T 细胞凋亡；EGFR-AS1 与 EGFR 共定位并相互作用，促进 MYC 活性；MYC 被鉴定为 PD-L1 的转录激活因子。