DDR2 controls the epithelial-mesenchymal-transition-related gene expression via c-Myb acetylation upon matrix stiffening

Daehwan Kim,Sangmyung Rhee,Jung-Woong Kim,Jangho Jeong,Panseon Ko,Eunae You

doi:10.1038/s41598-017-07126-7

Daehwan Kim, Sangmyung Rhee + Show 4 more

Open Access

https://doi.org/10.1038/s41598-017-07126-7

Copy DOI

Journal: Scientific Reports	Publication Date: Jul 28, 2017
Citations: 42	License type: open-access

Affiliation: Chung-Ang University

Abstract

Increasing matrix stiffness caused by the extracellular matrix (ECM) deposition surrounding cancer cells is accompanied by epithelial–mesenchymal transition (EMT). Here, we show that expression levels of EMT marker genes along with discoidin domain receptor 2 (DDR2) can increase upon matrix stiffening. DDR2 silencing by short hairpin RNA downregulated EMT markers. Promoter analysis and chromatin immunoprecipitation revealed that c-Myb and LEF1 may be responsible for DDR2 induction during cell culture on a stiff matrix. Mechanistically, c-Myb acetylation by p300, which is upregulated on the stiff matrix, seems to be necessary for the c-Myb-and-LEF1–mediated DDR2 expression. Finally, we found that the c-Myb–DDR2 axis is crucial for lung cancer cell line proliferation and expression of EMT marker genes in a stiff environment. Thus, our results suggest that DDR2 regulation by p300 expression and/or c-Myb acetylation upon matrix stiffening may be necessary for regulation of EMT and invasiveness of lung cancer cells.

Highlights

Fibrosis is related to fibroblast activation and mechanical remodelling of the extracellular matrix (ECM), resulting in tissue architecture destruction and increased matrix stiffness[1, 2]
It has been reported that focal adhesion (FA) signalling is essential for cellular spreading on a substrate in response to sensing the matrix stiffness[20]; we tested whether cell spreading on a stiff matrix is mediated by the canonical FA signalling (Fig. 1b,c)
We demonstrated that discoidin domain receptor 2 (DDR2) upregulation during cell culture on a stiff matrix may be crucial for expression of a set of epithelial–mesenchymal transition (EMT) marker genes

Summary

Introduction

Fibrosis is related to fibroblast activation and mechanical remodelling of the extracellular matrix (ECM), resulting in tissue architecture destruction and increased matrix stiffness[1, 2]. ECM rigidity increased by fibrosis in tumour tissue has been found to be linked to pathological conditions including cancer cell proliferation and epithelial– mesenchymal transition (EMT)[2, 3]. A stiffened ECM in the tumour microenvironment confers elongated morphology onto the cells and promotes motility accompanied by expression of proliferation- and EMT-related factors such as Snail, Twist, and N-cadherin[2, 5,6,7]. EMT involves promotion of tissue fibrosis, which reciprocally ensures a permissive microenvironment for cancer cell delamination from primary tumours and invasion through the ECM7. Our results suggest that DDR2 upregulated by matrix stiffening can play a critical role in EMT marker expression and invasiveness

Methods

Results

Conclusion