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1 Background: cardia adenocarcinoma (Gastric cardia adenocarcinoma, GCA) is one of the most common malignant tumor in northern China. GCA significant epidemiological characteristics is its consistency with esophageal cancer (Esophageal squamous cell carcinoma, ESCC) regional distribution. The last two decades around the world, particularly the the stomach distal parts of the United States and some European countries, the incidence of tumors was significantly decreased, showing a rising trend in the incidence of esophageal and gastroesophageal junction adenocarcinoma, the incidence rate of 20% growth rate increased year by year, an increase of nearly six times, is one of the fastest growth rate of all malignancies, the reason is not yet clear. At present, China's research for the cardia is not in-depth, its molecular mechanisms known to be very limited. Gene RASSF1A (Ras association domain family 1 A) is a new kind of candidate tumor suppressor gene RASSF1A gene methylation is common in many tumors such as lung cancer, nasopharyngeal cancer, liver cancer, and gastric cardia our and other laboratory previous studies found frequent molecules event. Interesting: there are large differences in laboratories reported RASSF1A methylation data. In this regard, we propose that the assumptions, the existence of different macroscopic type of gastric cardia adenocarcinoma RASSF1A gene methylation status. We have conducted studies have shown that higher responsibility doors adenocarcinoma RASSF1A methylation changes. The purpose of this study is to through the detection of RASSF1A gene methylation a different general classification cardia adenocarcinoma, and to further explore the link between RASSF1A methylation and cardia adenocarcinoma clinical pathological factors, deepen cancer molecular mechanisms of GCA understanding. 2 Materials and Methods: 81 cases of gastric cardia adenocarcinoma and 20 cases of normal tissue taken from the same individual corresponding adjacent state forest in 2005 (formerly Linxian) City the Yao village esophageal Hospital surgical resection specimens in all patients before surgery were not receiving radiation therapy and chemotherapy. 81 patients, male 53 cases, female 28 cases. The oldest was 75 years old, the minimum age of 40, average age 60 ± 8 years. Organizations drawn to take care of different advanced cardiac general classification. The advanced cardiac general classification criteria are not exactly the same, here will be divided into four types, including 32 cases of infiltrating; limitations of ulcers in 18 cases; fungating 17 cases; 14 cases of ulcerative infiltration. The clinical and pathological data of patients were recorded at the same time, the degree of differentiation, lymph node metastasis, depth of invasion, and TNM staging. All diagnosis and staging were confirmed by surgery and pathology. GCA tissue of RASSF1A gene promoter methylation using methylation-specific polymerase chain reaction (MSP) detection. All data were confirmed by SPSS10.0 system for statistical processing, analysis of each variable x ~ 2 test, test taken significant level α = 0.05, P <0.05 was significant meaning. 3 Results: the 3.1 the GCA organization and normal tissue RASSF1A gene promoter hypermethylation incidence. 81 cases of gastric cardia adenocarcinoma in 58 cases (72%) RASSF1A gene methylation positive. One cases (5%) RASSF1A gene methylation positive in 20 cases of distal cancerous tissues. The lower incidence of methylation in normal cardiac tissue cancer tissue (P <0.05). 3.2 RASSF1A gene promoter methylation with GCA macroscopic type relationship. Ulcer type RASSF1A methylation occurs rate of 79% (11/14), the limitations ulcerative methylation rate of 78% (14/18), infiltrating methylation occurred in 81 patients with cardiac infiltration rate 69% (22/32), the the fungating methylation incidence of 65% (11/17), no statistically significant differences between groups (P> 0.05). 3.3 RASSF1A gene promoter methylation with GCA between clinicopathological factors. Male patients RASSF1A gene promoter region methylation positive rate was 68% (36/53), methylation positive female patients was 79% (22/28). RASSF1A gene promoter methylation-positive rate of the younger group, elderly patients were 78%, 66%. Group of well-differentiated, moderately differentiated group, poorly differentiated group RASSF1A gene promoter methylation-positive rate was 73%, 83%, 63%, respectively. According to the TNM stage, the GCA was divided into the mid 38 cases, 43 cases, in the late RASSF1A gene promoter region methylation-positive rate of 70% and 73%, respectively. Cardia patients' gender, age, tumor differentiation and TNM staging has nothing to do with the RASSF1A gene promoter methylation between (P> 0.05). 4 Conclusion: 4.1 GCA organization RASSF1A methylation positive rate is much higher than that of normal tissue, is a frequent molecular event in the process of gastric cardia cancer. RASSF1A methylation positive rate of 4.2 in the a different general classification GCA organization similar does not support our hypothesis. 4.3 RASSF1A gene methylation positive rate cardia clinicopathological factors, the lack of the necessary link.
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