Hypermethylation of EDNRB promoter contributes to the risk of colorectal cancer

Cheng Chen,Leiting Xu,Yi Huang,Fei Chen,Qi Liao,Huadan Ye,Lingyan Wang,Shiwei Duan,Meng Ye

doi:10.1186/1746-1596-8-199

Abstract

ObjectiveColorectal cancer (CRC) is one of the most common digestive malignancies in the world. EDNRB is a new candidate tumor suppressor gene which is often down-regulated or even silenced by promoter hypermethylation in various human cancers. However, the function of EDNRB gene in CRC remains unknown. In this study, we examined the expression and DNA methylation of EDNRB in CRC tissues.MethodsA total of 42 paired CRC and adjacent normal tissue samples were used to determine mRNA levels and DNA methylation status of EDNRB gene by qRT-PCR and methylation-specific PCR (MSP), respectively.ResultsOur study showed that EDNRB promoter hypermethylation was more frequently in CRC tissues than in the normal tissues (92.86 versus 59.52, p = 0.001). Consequently, significantly lower level of EDNRB mRNA was found in CRC tumor samples than in normal samples (0.31 ± 0.91 versus 0.70 ± 1.18, p = 0.032).ConclusionsOur results suggested that EDNRB promoter hypermethylation might downregulate its gene expression in CRC, and thus played an important role in the development of CRC.The virtual slideThe virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7420980471113303

Highlights

Colorectal cancer (CRC) is a malignant disease caused by a variety of factors involving with the accumulation of genetic and epigenetic changes
Our study showed that Endothelin receptor type B (EDNRB) promoter hypermethylation was more frequently in CRC tissues than in the normal tissues (92.86 versus 59.52, p = 0.001)
Significantly lower level of EDNRB mRNA was found in CRC tumor samples than in normal samples (0.31 ± 0.91 versus 0.70 ± 1.18, p = 0.032)

Summary

Introduction

Colorectal cancer (CRC) is a malignant disease caused by a variety of factors involving with the accumulation of genetic and epigenetic changes. The mortality of CRC has soared up to 33. CRC has become the second most common cancer in the world [2], accounting for 9 of all malignant tumors deaths [3]. 5year survival rate of CRC patients has been improved from 22 to 47 in the last 30 years due to the advancement of the early diagnosis, surgical techniques and adjuvant therapies, the overall survival rate remains disappointing. Abberrant expression of some important genes, such as beta-catenin [4], SATB1 [5] and EGFR [6], were shown to be significantly associated with the occurrence and prognosis of CRC. DNA methylation alteration has been considered as an important event in many malignancies including CRC

Methods

Results

Conclusion