title: Induction of PD-L1 expression by epidermal growth factor receptor-mediated signaling in esophageal squamous cell carcinoma.
abstract: OBJECTIVE
  The purpose of this study was to investigate the potential effect of activation of epidermal growth factor receptor (EGFR) signaling pathway on the expression of programmed death-ligand 1 (PD-L1) in esophageal squamous cell carcinoma (ESCC) cells with EGFR overexpression.
  
  
  METHODS
  Flow cytometry and Western blot methods were used to assess PD-L1 expression on ESCC cells when EGFR signaling pathway was activated by epidermal growth factor (EGF) with or without EGFR-specific inhibitor AG-1478, and then EGFR signaling array was applied to analyze the potential signaling pathways involved.
  
  
  RESULTS
  This study found that PD-L1 expression increased significantly in an EGFR-dependent manner by the activation of EGFR signaling and decreased sharply when EGFR signaling was blocked. The upregulated expression of PD-L1 was not associated with EGFR-STAT3 signaling pathway, but may be affected by EGFR-PI3K-AKT, EGFR-Ras-Raf-Erk, and EGR-PLC-γ signaling pathways.
  
  
  CONCLUSIONS
  The expression of PD-L1 can be regulated by EGFR signaling activation in ESCC, which indicates an important role for EGFR-mediated immune escape and potential molecular pathways for EGFR-targeted therapy and immunotherapy.
authors.affiliation: Department of Radiation Oncology.
authors.forename: Wencheng
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology.
authors.forename: Qingsong
authors.initials: Q
authors.lastname: Pang
authors.affiliation: Department of Immunology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, People's Republic of China.
authors.forename: Cihui
authors.initials: C
authors.lastname: Yan
authors.affiliation: Department of Radiation Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Qifeng
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Jingsong
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Radiation Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Shufei
authors.initials: S
authors.lastname: Yu
authors.affiliation: Department of Radiation Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Radiation Oncology.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Yuan
authors.affiliation: Department of Radiation Oncology.
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Zefen
authors.initials: Z
authors.lastname: Xiao
keywords: epidermal growth factor receptor; esophageal squamous cell carcinoma; immune checkpoint; programmed death-ligand 1