The Study Of The Expression Of Two Transcripts Of NGX6 Gene And Clinicopathological Features Of Colorectal Carcinoma

[Background]Colorectal Carcinoma (CRC) is a common malignant tumor. Its incidence and mortality are very high. NGX6 (Nasopharyngeal carcinoma-associated gene 6), which was cloned by Cancer Research Institute of Central South University with position-candidate cloning strategy. Previous overall studies showed that NGX6 gene with all the transcripts low-regulated in colorectal carcinoma and the expression of NGX6 in colorectal carcinoma with lymph-node or distance metastasis was significantly lower than that in CRC without metastasis, which indicated that low-regulated or deletion of NGX6 gene may related to colorectal carcinoma's occurrence, development and metastasis. However, with the in-depth study in recent years, researchers found there were three transcripts by different splicing, named as NGX6-1, NGX6-2 and NGX6-3. NGX6-1 and NGX6-2 translate the same protein which contained 472 amino acids, and we named them as NGX6-L. NGX6-3 translates another protein containing 338 amino acids, which was named as NGX6-S. The function of different transcripts of NGX6 in CRC is unknow.[Objects]1) Based on the previously studies, to investigate the expression of NGX6-L and NGX6-S in colorectal carcinoma, to find the transcript fragments of NGX6 with real anti-tumor effect, and to provide a new basis for research of the inhibitary mechanism of NGX6 in colorectal carcinoma proliferation, invasion and metastasis.2) To explore the relationship between the occurrence colorectal carcinoma and clinicopathological features by retrospective analysis.[Methods]1) In this study, we collected 100 CRC patients' tissues of carcinoma and its paired normal tissues. Then we detected the expression of the two transcripts in colorectal carcinoma and corresponding normal tissue, with or without lymph node metastasis and distance metastasis of colorectal cancer tissues with in situ hybridization by using designed different probes of NGX6 transcripts. 2) We collected 261 cases of CRC and analyzed the relationship of the biological occurrence of colorectal carcinoma and its clinical pathological characteristics via data processing, analysis, and various statistical methods.[Results]1) The expression of NGX6-S was higher than that of NGX6-L in carcinoma tissues of colorectal cancer (p=0.008) . The significance was the same as that in patients with colon cancer, Dukes B stage, and in patients without lymph-node or distance metastasis. In patients without distance metastasis, the expression of NGX6-S in carcinoma tissues was higher than those in normal tissues. Inversely, in patients with distance metastasis, the expression of NGX6-S in carcinoma tissues was lower than those in normal tissues. The expression of NGX6-L was no different between carcinoma tissues and normal tissues. The expression of the two transcripts had no correlation with the leval of CEA.2) Poorly differentiated cancers were common in young patients with CRC, while well-differentiated cancers were common in old patients with CRC. Diameter of colorectal carcinoma was associated with Dukes's stages and differentiation grade. The leval of CEA was associated with metastasis of CRC.[Conclusions]1) The expression of NGX6-S was higher in olorectal carcinoma tissues than NGX6-L. The low expression of NGX6-S was related to distance metastasis and invasion. The expression of the two transcripts had no correlation with the leval of CEA.2) Differentiated grade of colorectal carcinoma was related to age. The level of CEA was closely associated with the advanced colorectal cancer. Diameter of colorectal carcinoma was related to Dukes's stages and differentiation grade. The leval of CEA was associated with metastasis of CRC.