NDRG2 gene copy number is not altered in colorectal carcinoma

作     者：Anders Lorentzen Cathy Mitchelmore 

作者机构：Eucaryotic Cell Biology Department of Science and Environment Roskilde University 

出 版 物：《World Journal of Clinical Oncology》 (世界临床肿瘤学杂志（英文版）)

年 卷 期：2017年第8卷第1期

页      面：67-74页

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

基　　金：The Danish Cancer Society No.DP05117 

主　　题：N-myc downstream-regulated gene 2 Colorectal carcinoma MYC Tumor suppressor Allelic loss Gene amplification Copy number 

摘      要：AIM To investigate if the down-regulation of N-myc Downstream Regulated Gene 2(NDRG2) expression in colorectal carcinoma(CRC) is due to loss of the NDRG2 allele(s).METHODS The following were investigated in the human colorectal cancer cell lines DLD-1, Lo Vo and SW-480: NDRG2 mRNA expression levels using quantitative reverse transcriptionpolymerase chain reaction(qRT-PCR); interaction of the MYC gene-regulatory protein with the NDRG2 promoter using chromatin immunoprecipitation; and NDRG2 promoter methylation using bisulfite ***, we performed qPCR to analyse the copy numbers of NDRG2 and MYC genes in the above three cell lines, 8 normal colorectal tissue samples and 40 CRC tissue *** As expected, NDRG2 mRNA levels were low in the three colorectal cancer cell lines, compared to normal *** MYC protein interacted with the NDRG2 core promoter in all three cell *** addition, the NDRG2 promoter was heavily methylated in these cell lines, suggesting an epigenetic regulatory *** gene copy numbers of NDRG2 were observed in the three cell *** the colorectal tissues, one normal and three CRC samples showed partial or complete loss of one NDRG2 *** contrast, the MYC gene was amplified in one cell line and in more than 40% of the CRC *** Our study suggests that the reduction in NDRG2 expression observed in CRC is due to transcriptional repression by MYC and promoter methylation, and is not due to allelic loss.