Department of Oncology, Affiliated Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu 210006, PR China.
Mol Med Rep. 2011 Nov-Dec;4(6):1139-43. doi: 10.3892/mmr.2011.578. Epub 2011 Aug 31.
DNA methyltransferase (DNMT) 1, DNMT3A and DNMT3B, which affect promoter CpG methylation status, play a significant role in cancer development. Little is known regarding the clinical significance of DNMT expression in gastric cancers. Expression of DNMT1, DNMT3A and DNMT3B in paraffin sections from 54 gastric cancer patients were examined using immunohistochemistry, and their associations with the corresponding clinicopathological parameters were analyzed using the Chi-square test. Overexpression of DNMT1, DNMT3A and DNMT3B in gastric cancer tissues was observed in 35 (64.8%), 38 (70.4%) and 28 (51.9%) of 54 cases, respectively. DNMT1 was localized in the cytoplasm and nuclei of the cancer cells, whereas DNMT3A and DNMT3B were detected only in the cytoplasm. DNMT1 expression was more frequently found in tumors localizing at the cardia or body of the stomach (P=0.048). DNMT3A was associated with TNM stage (P=0.001) and lymph node metastasis (P=0.002). No significant correlation was found between DNMT3B expression and clinicopathological data (P>0.05). The co-expression of DNMT1 and DNMT3A, and of DNMT3A and DNMT3B was more frequently found in tumors localizing at the cardia or body of the stomach (P=0.005 and P=0.009 respectively). Moreover, co-expression of DNMT1 and DNMT3A was significantly associated with lymph node metastasis (P=0.035). DNMTs are overexpressed in gastric cancer, and may play a significant role in the development of aberrant promoter methylation during tumorigenesis.
DNA 甲基转移酶 (DNMT)1、DNMT3A 和 DNMT3B 会影响启动子 CpG 甲基化状态，在癌症的发生发展中发挥着重要作用。然而，关于胃癌中 DNMT 表达的临床意义知之甚少。本研究采用免疫组织化学方法检测了 54 例胃癌石蜡切片中 DNMT1、DNMT3A 和 DNMT3B 的表达情况，并采用卡方检验分析其与相应临床病理参数的关系。结果显示，在 54 例胃癌组织中，DNMT1、DNMT3A 和 DNMT3B 的过表达率分别为 64.8%、70.4%和 51.9%。DNMT1 定位于癌细胞的细胞质和细胞核，而 DNMT3A 和 DNMT3B 仅定位于细胞质。DNMT1 的表达在胃贲门或胃体部肿瘤中更为常见（P=0.048）。DNMT3A 与 TNM 分期（P=0.001）和淋巴结转移（P=0.002）相关。DNMT3B 的表达与临床病理数据之间无显著相关性（P>0.05）。DNMT1 和 DNMT3A 以及 DNMT3A 和 DNMT3B 的共表达在胃贲门或胃体部肿瘤中更为常见（P=0.005 和 P=0.009）。此外，DNMT1 和 DNMT3A 的共表达与淋巴结转移显著相关（P=0.035）。胃癌中 DNMTs 过表达，并且在肿瘤发生过程中异常启动子甲基化的发展中可能发挥着重要作用。
