Expression of tumor related genes NGX6,NAG-7,BRD7 in gastric and colorectal cancer

AIM: NGX6, NAG-7 and BRD7 genes are tumor related genes, which have been newly cloned by positional candidate cloning strategy. This study was designed to investigate the expression levels of NGX6, NAG-7 and BRD7 genes in human gastric and colorectal cancer tissues, and their corresponding normal tissues, and to investigate whether these genes play a role in the pathogenesis of gastric and colorectal cancers.METHODS: Reverse transcription-polymerase chain reaction (RT-PCR), dot hybridization and Northern blot analysis were used to compare the expression levels of NGX6, NAG-7 and BRD7 genes in 34 gastric cancer tissues and 34 colorectal cancer tissues with their corresponding normal tissues of the same patients, respectively.RESULTS: Among the 34 colorectal cancer specimens and the 34 gastric cancer specimens, the expression of NGX6 in 25 colorectal cancer tissues was absent or very weak (73.5 %) by RT-PCR analysis. The down-regulation rate of NGX6 in colorectal cancer tissues was significantly higher than that in corresponding normal tissues (26.5 %,9/34)(P＜0.005). Moreover, the down-regulation of NGX6 was significantly correlated with lymph node and/or distance metastases. Patients with lymph node and/or distance metastasis had much higher down-regulation rate of NGX6 than patients without metastases (93.8 % vs 55.6 %, P＜0.05).However no correlation was found between the expression of NGX6 and pathologic type of colorectal cancer in this study, and also the expression of NGX6 did not display any difference between gastric cancer and corresponding normal tissues (58.8 % vs 70.6 %, P＞0.25). Dot hybridization and Northern blot analysis confirmed the results of RT-PCR.Furthermore, NAG-7 and BRD7 mRNA was not up- or downregulated in gastric and colorectal cancers compared with their corresponding normal tissues in our study.CONCLUSION: The down-regulation of NGX6 may be closely associated with tumorigenesis and metastasis of colorectal carcinoma. However, it may not contribute to the development and progression of gastric carcinoma. In addition, the expression levels of NAG-7, and BRD7 did not alter in gastric and colorectal cancers. This seems to suggest that NAG-7and BRD7 genes may not play a role in gastric and colorectal carcinogenesis.

肿瘤相关基因NAG6、NAG-7、BRD7在胃癌中的表达

目的 NAG6、NAG 7、BRD7为最近克隆的肿瘤相关新基因 ,对它们在胃癌及癌旁组织中的表达进行检测 ,探讨这些基因在胃癌发生发展中的作用。方法 采用RT PCR、Northern杂交、点杂交方法检测 34例胃癌和癌旁组织中这些基因的表达。结果 胃癌组织中 ,有 61 .8% (2 1 / 34)NAG6基因表达缺失 ,NAG6在胃癌组织中的表达较癌旁组织显著下调 (P <0 .0 1 ) ,但NAG6表达下调与胃癌淋巴结或远处转移无明显关系 (P >0 .0 5)。NAG 7基因在胃癌和癌旁组织中表达率分别为 88.2 % (30 / 34)和 82 .3 % (2 8/ 34)。BRD7基因在胃癌及癌旁组织中均有表达。RT PCR、Northern杂交、点杂交结果均显示NAG 7、BRD7基因在胃癌与癌旁组织之间的表达差异无显著性。同时 ,点杂交也证实NAG6在胃癌组织中表达下调。结论 NAG6基因在胃癌组织中表达显著下调 ,这可能在胃癌的发生发展过程中起重要作用 ,但可能与淋巴结或远处转移无关。BRD7、NAG 7基因在胃癌中未发现表达水平改变 。

NAG7基因转染HNE1细胞后下调蛋白质的鉴定及其意义(英文)

NAG7基因是我室克隆的与鼻咽癌相关的肿瘤抑制候选基因 .将NAG7编码框的cDNA片段克隆至pGEM3.1(+ )的表达载体 ,经脂质体转染入HNE1细胞 ,经G4 18筛选 ,并运用PCR技术证实 .建立含NAG7基因稳定转染的细胞系 ,抽提细胞总蛋白质 ,双向凝胶电泳分离蛋白质 ,对表达下调的蛋白质点进行质谱分析 ,获得的肽质指纹经SWISS PROT数据库分析以鉴定蛋白质点 .鉴定出的 7个下调蛋白质包括纤溶酶原、收缩蛋白、Ras 相关蛋白Rab 36及ARF 相关蛋白等 .通过对蛋白质性质和功能的分析 ,发现这些蛋白质参与了细胞信号的转导、蛋白质的转运及细胞代谢等众多事件 .因此 。