Expression And Clinical Significance Of CHD5in Gastric Carcinoma

Background and ObjectiveGastric cancer is one of the most common digestive tract cancer with high mortality both in China and abroad. It is well known that the development of tumor is a polygenic, multi-step synergy biology behavior, The studies of tumor suggest that the the activation of oncogenes and the inactivation of tumor suppressor gene play an important role in the etiology of tumor.Although the incidence of gastric cancer is slightly down and the early diagnosis has been improved in these years, therapeutic efficacy is still unsatisfactory. One important area of research is gene discovery, and identifying and characterizing more gastric cancer genes be of great significance in experimental and clinical meaning.A large number of studies indicate that human chromosome1p36area in a variety of human tumors, especially in the patients with malignant tumor are lack of expression, prompt the area there are one or more important candidate tumor suppressor genes, a large number of studies of genomic analysis in different kinds of cancers indicate that deletion encompassing1p36is frequent, suggesting the existence of a or more tumor suppressors gene in this region. Chromo domain helicase DNA-bindingprotein5(CHD5) at1p36is a novel candidate tumor suppressor gene identified by the Brodeur group in2003. In2007, Bagchi et a1identified CHD5 as a tumor suppressor gene through functional analysis in mouse models. More studies on CHD5are being published, but the gene has not been fully studied in gastric cancer. In this study, We use RT-PCR and Immunohistochemical (streptavidin-perosidase method) to discuss the role of CHD5as a tumor-suppressor gene in the gastric cancer and adjacent tissues tissue(5cm away from cancer). We hope to good understanding the role of CHD5promoter methylation and phenotypic expression in gastric cancer and feasible chemo preventive measures for the future.Material and method1.63cases of gastric cancer and adjacent tissues tissue(5cm away from cancer) which were surgically resected from December2010to February2012in the First Affiliated Hospital of Zhengzhou university were collected. All specimens are confirmed by experienced pathological doctor, and all the patients have not been accepted radiation and chemotherapy and other immunology treatment before operation. Specimens are put into-80℃fridge to preserve.2. We use RT-PCR and Immunohistochemistry (streptavidin-perosidase method) to detect CHD5mRNA and the protein in the above tissues.3. Assembled data were analyzed with software SPSS17.0. Significant differences between the two sample quantitative detection were compared with t-test. Two of the sample rate compares the4case for statistical significance by the χ~2-test, All P-values were derived from two-sided tests and a probability less than0.05was considered statistically significant.Results1. The expression level of CHD5mRNA in gastric cancer tissues was lower than that in paired adjacent gastric cancer tissues(0.06±0.04vs0.34±0.06, t=59.204, P<0.01).In gastric cancer tissues, the expression of CHD5mRNA has significant associations with histologic differentiation, stages of TNM in gastric cancer and lymph node metastasis (all P<0.05).2. The positive rate of CHD5expression in gastric cancer tissues was36.5%, which is 71.4%in paired adjacent gastric cancer tissues. The expression of CHD5protein wascorrelated with histologic differentiation, stages of TNM in gastric cancer and lymph node metastasis (all P<0.05).3. In the63cases of gastric cancer,there is obvious correlation between mRNA and protein expression of CHD5(P<0.01)Conclusions1. The expression level of CHD5mRNA in gastric cancer tissues was lower than that in paired adjacent gastric cancer tissues, and the expression of CHD5mRNA has significant associations with histologic differentiation, stages of TNM in gastric cancer and lymph node metastasis, which suggests that CHD5may be a key gene involved in gastric cancer.2. The expression of CHD5protein was correlated with histologic differentiation, stages of TNM in gastric cancer and lymph node metastasis,which suggests CHD5might play an important role in carcinogenesis and progression of gastric cancer.3. Deficiency expression of mRNA is accompanied by deficiency expression of protein obviously.