Zhang Xiao-Mei, Sheng Shou-Rong, Wang Xiao-Yan, Bin Liang-Hua, Wang Jie-Ru, Li Gui-Yuan
Department of Digestive Medicine, the Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China.
World J Gastroenterol. 2004 May 1;10(9):1361-4. doi: 10.3748/wjg.v10.i9.1361.
NAG6 gene is a novel tumor related gene identified recently. This study was designed to examine the expression of this gene in gastric cancer and corresponding normal tissues, and to investigate its role in the occurrence and development of gastric cancer, also to study if the genetic structure of NAG6 was altered in gastric cancer.
Reverse transcription-polymerase chain reaction (RT-PCR), Northern blot analysis and dot hybridization were used to compare the expression level of NAG6 gene in 42 cases of gastric cancer tissues with their corresponding normal tissues of the same patients respectively. In addition, restriction fragment length polymorphism (RFLP) analysis was adopted to study if the genetic structure of NAG6 was altered in gastric carcinomas.
The expression of NAG6 in 57.1% gastric cancer tissues (25/42) was absent by RT-PCR analysis. The down-regulation rate of NAG6 in gastric cancer tissues was significantly higher than that in corresponding normal tissues (P<0.01). However no correlation between the down-regulation of NAG6 and lymph-node and/or distance metastasis was found in this study (P>0.05). Dot hybridization confirmed the results of RT-PCR. Furthermore, the results of EcoRI RFLP analysis of NAG6 gene demonstrated that 3 of 7 cases of gastric cancer showed loss of 5 kb fragment in comparison with their corresponding normal tissues.
NAG6 gene is significantly down regulated in gastric cancer. The loss of genetic materials may be the cause of down-regulation of NAG6 expression. This seems to suggest that NAG6 may represent a candidate of putative tumor suppressor gene at 7q31-32 loci associated with gastric carcinoma. The down-regulation of this gene may play a role in occurrence and development of this disease, however it may not be associated with lymph node and/or distance metastasis.
NAG6基因是最近鉴定出的一种新型肿瘤相关基因。本研究旨在检测该基因在胃癌组织及相应正常组织中的表达情况，探讨其在胃癌发生发展中的作用，并研究胃癌中NAG6基因的结构是否发生改变。
分别采用逆转录-聚合酶链反应（RT-PCR）、Northern印迹分析和点杂交法，比较42例胃癌组织及其相应正常组织中NAG6基因的表达水平。此外，采用限制性片段长度多态性（RFLP）分析研究胃癌中NAG6基因的结构是否改变。
RT-PCR分析显示，57.1%（25/42）的胃癌组织中NAG6基因表达缺失。胃癌组织中NAG6基因的下调率显著高于相应正常组织（P<0.01）。然而，本研究未发现NAG6基因下调与淋巴结转移和/或远处转移之间存在相关性（P>0.05）。点杂交证实了RT-PCR的结果。此外，NAG6基因的EcoRI RFLP分析结果显示，7例胃癌中有3例与其相应正常组织相比，5 kb片段缺失。
NAG6基因在胃癌中显著下调。遗传物质的缺失可能是NAG6基因表达下调的原因。这似乎表明，NAG6基因可能是位于7q31-32位点的潜在抑癌基因的候选基因，与胃癌相关。该基因的下调可能在胃癌的发生发展中起作用，但可能与淋巴结转移和/或远处转移无关。
