Colorectal Cancer
Copyright ©The Author(s) 2003. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 15, 2003; 9(8): 1729-1733
Published online Aug 15, 2003. doi: 10.3748/wjg.v9.i8.1729
Expression of tumor related genes NGX6, NAG-7, BRD7 in gastric and colorectal cancer
Xiao-Mei Zhang, Shou-Rong Sheng, Xiao-Yan Wang, Jie-Ru Wang, Jiang Li
Xiao-Mei Zhang, Xiao-Yan Wang, Department of Digestion Medicine, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
Shou-Rong Sheng, Department of Digestion Medicine, The Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
Jie-Ru Wang, Jiang Li, Carcinoma Research Institute, Xiangya Medical School, Central South University, Changsha 410078, Hunan Province, China
Supported by the Natural Science Foundation of Hunan Province No.01JJY2102 and the National “863 Program” of China, No.102-10-01-05
Correspondence to: Dr. Shou-Rong Sheng, Department of Digestion Medicine, The Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China. tangyy@public.cs.hn.cn
Telephone: +86-731-4316667 Fax: +86-731-4316667
Received: April 2, 2003
Revised: April 14, 2003
Accepted: May 19, 2003
Published online: August 15, 2003
Abstract

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 down-regulated 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-7 and BRD7 genes may not play a role in gastric and colorectal carcinogenesis.

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