Department of Gastroenterology & Hepatology, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853 China.
Department of Geriatric Digestive System, Chinese PLA Navy General Hospital, 6 Fucheng Road, Beijing, 100048 China.
Clin Epigenetics. 2017 Oct 18;9:115. doi: 10.1186/s13148-017-0417-4. eCollection 2017.
ZNF331 was reported to be a transcriptional repressor. Methylation of the promoter region of ZNF331 has been found frequently in human esophageal and gastric cancers. The function and methylation status of ZNF331 remain to be elucidated in human colorectal cancer (CRC).
Six colorectal cancer cell lines, 146 cases of primary colorectal cancer samples, and 10 cases of noncancerous colorectal mucosa were analyzed in this study using the following techniques: methylation specific PCR (MSP), qRT-PCR, siRNA, flow cytometry, xenograft mice, MTT, colony formation, and transfection assays.
Loss of ZNF331 expression was found in DLD1 and SW48 cells, reduced expression was found in SW480, SW620, and HCT116 cells, and high level expression was detected in DKO cells. Complete methylation of the ZNF331 in the promoter region was found in DLD1 and SW48 cells, partial methylation was found in SW480, SW620, and HCT116 cells, and unmethylation was detected in DKO cells. Loss of/reduced expression of ZNF331 is correlated with promoter region methylation. Restoration of ZNF331 expression was induced by 5-aza-2'-deoxycytidine (DAC) in DLD1 and SW48 cells. These results suggest that ZNF331 expression is regulated by promoter region methylation in CRC cells. ZNF331 was methylated in 67.1% (98/146) of human primary colorectal cancer samples. Methylation of ZNF331 was significantly associated with tumor size, overall survival (OS), and disease-free survival (DFS) ( < 0.01, < 0.01, < 0.05). Methylation of ZNF331 was an independent poor prognostic marker for 5-year OS and 5-year DFS (both < 0.05). ZNF331 suppressed cell proliferation and colony formation in CRC cells and suppressed human CRC cell xenograft growth in mice.
ZNF331 is frequently methylated in human colorectal cancer, and the expression of ZNF331 is regulated by promoter region methylation. Methylation of ZNF331 is a poor prognostic marker of CRC.
ZNF331 被报道为一种转录抑制因子。在人类食管和胃癌中，已发现 ZNF331 启动子区域的甲基化频繁发生。ZNF331 在人结直肠癌（CRC）中的功能和甲基化状态仍有待阐明。
本研究使用以下技术分析了 6 种结直肠癌细胞系、146 例原发性结直肠癌样本和 10 例非癌性结直肠黏膜：甲基化特异性 PCR（MSP）、qRT-PCR、siRNA、流式细胞术、异种移植小鼠、MTT、集落形成和转染实验。
在 DLD1 和 SW48 细胞中发现 ZNF331 表达缺失，在 SW480、SW620 和 HCT116 细胞中发现表达降低，在 DKO 细胞中发现高表达。在 DLD1 和 SW48 细胞中发现 ZNF331 启动子区域完全甲基化，在 SW480、SW620 和 HCT116 细胞中发现部分甲基化，在 DKO 细胞中发现未甲基化。ZNF331 表达缺失/降低与启动子区域甲基化相关。在 DLD1 和 SW48 细胞中，5-氮杂-2'-脱氧胞苷（DAC）诱导 ZNF331 表达恢复。这些结果表明 ZNF331 在 CRC 细胞中的表达受启动子区域甲基化调控。在 146 例人原发性结直肠癌样本中，ZNF331 发生甲基化的比例为 67.1%（98/146）。ZNF331 的甲基化与肿瘤大小、总生存期（OS）和无病生存期（DFS）显著相关（均 P<0.01，均 P<0.01，均 P<0.05）。ZNF331 甲基化是影响 5 年 OS 和 5 年 DFS 的独立不良预后标志物（均 P<0.05）。ZNF331 抑制 CRC 细胞的增殖和集落形成，并抑制人 CRC 细胞异种移植在小鼠中的生长。
ZNF331 在人结直肠癌中经常发生甲基化，ZNF331 的表达受启动子区域甲基化调控。ZNF331 甲基化是 CRC 的不良预后标志物。
