The role of ZEB1 in the inflammation-induced promotion of EMT in HNSCC

Abstract

Objectives: To determine the role of ZEB1 in the inflammation-induced promotion of the epithelial-mesenchymal transition (EMT) in head and neck squamous cell carcinoma (HNSCC). Study Design: A molecular biology study. Real-time quantitative reverse-transcriptase polymerase chain reaction (RT-PCR), Western blot analysis, and immunohistochemical staining of human HNSCC tissue sections were used to determine how inflammation affects the transcriptional repressor, ZEB1. Setting: An academic hospital laboratory. Subjects and Methods: Relative ZEB1 RNA levels were determined by RT-PCR, and protein expression was evaluated in situ by immunohistochemical staining of human HNSCC tissue sections. Results: IL-1β-treated HNSCC cell lines demonstrated a significant decrease in E-cadherin mRNA and an increase in the mRNA expression of the transcriptional repressor ZEB1. IL-1β exposure led to enhanced ZEB1 binding at the chromatin level, as determined by chromatin immunoprecipitation assays (ChIP). An inverse relationship between ZEB1 and E-cadherin was demonstrated in situ by immunohistochemical staining of human HNSCC tissue sections. Conclusions: Our recent investigations indicate that inflammatory mediators are potent regulators of EMT in HNSCC. This is the first report indicating the role of ZEB1 in the inflammation-induced promotion of EMT in HNSCC. This newly defined pathway for transcriptional regulation of E-cadherin in HNSCC has important implications for targeted chemoprevention and therapy.