Email updates

Keep up to date with the latest news and content from BMC Cancer and BioMed Central.

Open Access Highly Accessed Research article

Identification of novel driver mutations of the discoidin domain receptor 2 (DDR2) gene in squamous cell lung cancer of Chinese patients

Liyun Miao1, Yongsheng Wang1, Suhua Zhu2, Minke Shi3, Yan Li1, Jingjing Ding1, Jun Yang4, Qing Ye4, Hourong Cai1, Deping Zhang1, Hongbing liu2 and Yong Song2*

Author Affiliations

1 Department of Respiratory Medicine, Nanjing Drum Tower Hospital Affiliated to Medical School of Nanjing University, Zhongshan Road 321#, Nanjing 210008, China

2 Department of Respiratory Medicine, Jinling Hospital, Medical School of Nanjing University, East Zhongshan Road 305#, Nanjing 210002, Jiangsu Province China

3 Department of Cardiothoracic Surgery, Nanjing Drum Tower Hospital Affiliated to Medical School of Nanjing University, Zhongshan Road 321#, Nanjing 210008, China

4 Department of pathology, Nanjing Drum Tower Hospital Affiliated to Medical School of Nanjing University, Zhongshan Road 321#, Nanjing 210008, China

For all author emails, please log on.

BMC Cancer 2014, 14:369  doi:10.1186/1471-2407-14-369

Published: 24 May 2014

Abstract

Background

Although many of the recently approved genomically targeted therapies have improved outcomes for patients in non–small-cell lung cancer (NSCLC) with lung adenocarcinoma, little is known about the genomic alterations that drive lung squamous cell cancer (SCC) and development of effective targeted therapies in lung SCC is a promising area to be further investigated. Discoidin domain receptor 2 (DDR2), is a novel receptor tyrosine kinases that respond to several collagens and involved in tissue repair, primary and metastatic cancer progression.

Methods

Expression of DDR2 mRNA was analyzed in 54 lung SCC tissues by qRT-PCR. Over-expression approaches were used to investigate the biological functions of DDR2 and its’ mutations in lung SCC cells. Conventional Sanger sequencing was used to investigate the mutations of DDR2 gene in 86 samples. The effect of DDR2 and its’ mutations on proliferation was evaluated by MTT and colony formation assays; cell migration and invasion was evaluated by trasnwell assays. Lung SCC cells stably transfected with pEGFP-DDR2 WT, pEGFP-DDR2-S131C or empty vector were injection into nude mice to study the effect of DDR2 and its’ mutation on tumorigenesis in vivo. Protein and mRNA expression levels of E-cadherin and MMP2 were determined by qRT-PCR and western blot analysis. Differences between groups were tested for significance using Student’s t-test (two-tailed).

Results

In this study, we found that DDR2 mRNA levels were significantly decreased in 54 lung SCC tissues compared with normal lung tissues. Moreover, there were 3 novel DDR2 mutations (G531V, S131C, T681I) in 4 patients and provide the mutation rate of 4.6% in the 86 patients with lung SCC. The mutation of S131C in DDR2 could promote lung SCC cells proliferation, migration and invasion via inducing MMP-2, but reducing E-cadherin expression.

Conclusions

These data indicated that the novel DDR2 mutation may contribute to the development and progression of lung SCC and this effect may be associated with increased proliferation and invasiveness, at least in part, via regulating E-cadherin expression.

Keywords:
Squamous cell lung cancer; DDR2 mutation; Proliferation; Invasion; E-cadherin