Methylation Of Sfrp5 In Gastric Cancer Tissues And Its Clinical Significance

Gastric cancer accounts for more than 95% of gastric malignant tumor,of which the mortality is secondary to other malignant tumors in worldwide,and is still one of the common malignant tumors and a threat to human health in common diseases.In recent years,researches have shown that initiation and development of tumors are the interaction of genomics and epigenetics.Among them,DNA methylation is a major form of epigenetic modifications.Some scholars discover that the unusual activation of Wnt signaling pathways has close relation with the occurrence and development of tumors.A large number of studies have shown that silent expression of Wnt singaling pathways inhibitors,secreted frizzled-related proteins,caused by promoter methylation plays a important role in the process.Objective:In this study,we aimed to measure the Sfrp5 methylation in gastric cancer and normal tissue adjacent to carcinoma and to explore the clinical significance.Method:1 We choosed 90 samples of gastric cancer and 90 normal tissue adjacent to carcinoma sectioned and confirmed by pathology specimen in surgical in Second Affiliated Hospital of HeBei Medical University.Among the cancer tissues,73 were male,17 were female.Age arranges from 46 to 76,and the average is 64.Organization credits type:35cases were high and moderately differentiated adenocarcinoma,55 cases were poorly differentiated and undifferentiated adenocarcioma.Lymph node metastasis:33 cases had transfer and 57 had no transfer.Each patients were taken the primary tumor and normal tissue adjacent to carcinoma(far more than 5 cm away from the cut edge).The specimen were frozened in liquid nitrogen immediately whenobtained.Using HE staining to ensure the tumor specimen was mainly composed of tumor tissue and there were no tumor cell invasion in normal tissue adjacent to carcinoma.All patients experienced no chemotherapy and radiotherapy before operation and had complete clinical and pathological datas.Specimens dissatisfied with above conditions were excluded from the study.2 We used methylation specific PCR to analyze Sfrp5 methylation and operated strictly according to the instructions.3 All data were analyzed by SPSS 19.0 softwate.Enumeration data were expressed by percentage and compared with ?2 test and Fisher's exact probability analysis method.P<0.05 was considered statistically significant.Results:1 The protein level and gene methylation of Sfrp5 in gastric cancer and in normal tissue adjacent to carcinomaThe protein level of Sfrp5 in gastric cancer and normal tissue adjacent to carcinoma was 20%(18/90)and 90%(81/90)respectively,and the difference was statistically significant(P < 0.05).The Sfrp5 gene methylation rate in gastric cancer and normal tissue adjacent to carcinoma incidence was 82.2%(74/90)and 18.9%(17/90)respectively,and the difference was statistically significant(P < 0.05).2 The relationship of the Sfrp5 gene methylation rate with the clinical pathological parameters.The Sfrp5 gene methylation rate in group without lymph node metastasis66.7%(22/33)was significantly lower than with lymph node metastasis group86.0%(49/57),and the difference was statistically significant(P < 0.05);High differentiation group methylation rate 71.4%(25/35)was lower than the poorly differentiated and undifferentiated group methylation rate 81.8%(45/55),but there was no statistically significant difference(P > 0.05).Gene methylation rate was 84.5%(71/84)in greater than or equal to 50 years old age group was lower than 100%(6/6)in less than 50 years old age group.Thefemale group methylation rate 76.4%(13/17)was lower than male group76.7%(56/73),but there was no statistical difference(P > 0.05).Conclusions: The level of Sfrp5 gene methylation frequency increased in gastric cancer and decreased in protein level.Sfrp5 gene methylation may participate in the occurrence and development of gastric cancer.