Chen Jiayu, Liu Chibo, Yin Lihui, Zhang Wei
Department of Laboratory Medicine, School of Medicine, Taizhou University, Taizhou, Zhejiang, 318000, China.
Tumour Biol. 2015 Feb;36(2):1081-9. doi: 10.1007/s13277-014-2731-1. Epub 2014 Oct 19.
This study aimed to explore the tumor-promoting function of esophageal cancer-related gene 4 (ECRG4) in the papillary thyroid cancer and its related mechanism. ECRG4 Messenger RNA (mRNA) and protein expression analysis in papillary thyroid cancer tissues was performed by quantitative real-time PCR (Q-RT-PCR), Western blot, and immunohistochemistry methods. Ten pairs of fresh samples from the papillary thyroid carcinoma patients were analyzed for ECRG4 promoter CpG island methylation status by bisulfite sequencing analysis. We also transfected ECRG4 into papillary thyroid cancer cell lines W3 and K1 with lentivirus and analyzed ECRG4 functions through evaluating the changes of the proliferation activity, the cell cycle, and the cell apoptosis rate of these transformed cells. We found that ECRG4 expression was upregulated in most papillary thyroid cancer samples (70.0%, 28 out of 40 papillary thyroid cancer samples) on the protein level, and the ECRG4 mRNA level was also enhanced in tumor tissues compared to their matched nontumor tissues. CpG islands around the ECRG4 promoter region were demethylated in the papillary thyroid cancer samples. At the same time, the upregulated expression of ECRG4 in papillary thyroid cancer cell lines W3 and K1 could promote both the proliferation activity and the cell cycle transition from the G1 phase into the G2 but could not affect the cell apoptosis rate. The expression of ECRG4 is frequently upregulated in a papillary thyroid carcinoma through the demethylation mechanism of CpG islands in the gene promoter region, and the ECRG4 has a tumor-promoting function through inducing the cell cycle transition from the G1 phase to the G2 in papillary thyroid carcinoma cells.
本研究旨在探讨食管癌相关基因4（ECRG4）在甲状腺乳头状癌中的促肿瘤功能及其相关机制。通过定量实时PCR（Q-RT-PCR）、蛋白质免疫印迹法和免疫组织化学方法对甲状腺乳头状癌组织中的ECRG4信使核糖核酸（mRNA）和蛋白质表达进行分析。采用亚硫酸氢盐测序分析法对10对甲状腺乳头状癌患者的新鲜样本进行ECRG4启动子CpG岛甲基化状态分析。我们还通过慢病毒将ECRG4转染至甲状腺乳头状癌细胞系W3和K1中，并通过评估这些转化细胞的增殖活性、细胞周期和细胞凋亡率的变化来分析ECRG4的功能。我们发现，在大多数甲状腺乳头状癌样本中（70.0%，40例甲状腺乳头状癌样本中的28例），ECRG4蛋白水平表达上调，与配对的非肿瘤组织相比，肿瘤组织中的ECRG4 mRNA水平也有所增强。甲状腺乳头状癌样本中ECRG4启动子区域周围的CpG岛发生去甲基化。同时，ECRG4在甲状腺乳头状癌细胞系W3和K1中的表达上调可促进增殖活性以及细胞周期从G1期向G2期转变，但不影响细胞凋亡率。ECRG4在甲状腺乳头状癌中常通过基因启动子区域CpG岛的去甲基化机制而上调表达，且ECRG4通过诱导甲状腺乳头状癌细胞的细胞周期从G1期向G2期转变而具有促肿瘤功能。
