| Objective: To investigate the expression of anti-oncogene PTEN protein and the methylation of the promoter region in human gastric cancer and compared it with that of tumor-sideward mucosa and that of normal gastric tissues, to find the relationship with the biological behavior of gastric cancer proteinMethod: Immunohistochemistry was applied to examine the expression of PTEN protein in 50 cases of human gastric carcinoma, 20 cases of tumor-sideward mucosa and 8 cases of normal gastric. Methylation specific PCR method (MSP) was applied to examine the PTEN methylation of the promoter region in gastric cancer tissues and the corresponding adjacent tissues. Results were compared with clinical pathologic parameter such as histology type, lymphatic metastasis and clinical stage.Result: 1. PTEN expression results:â‘ PTEN protein positive stain particles mainly located in the cytoplasm.â‘¡The PTEN protein expression rate of gastric cancer is 62.00 percent (31 of 50), The PTEN protein expression rate of adjacent group is 90.00 percent (18 of 20), The PTEN protein expression rate of normal gastric mucosa group is 100% (8 of 8). The PTEN protein expression rate of gastric cancer was significantly higher than that of the adjacent group and the normal gastric mucosa group (p <0. 05).â‘¢there is no significant difference (P > 0. 05), between adjacent group and the normal gastric mucosa group in PTEN protein expression rate, but are higher than the cancer group (P < 0.005).â‘£The realationship between PTEN protein expression and clinicopathological features of gastric cancer:The PTEN protein positive rate between high school division group and poorly differentiated group (80.65 vs 31. 58%) had a significant difference (P <0. 05) ;The PTEN protein positive rate between invasion of serous group and not invasion of serous group(53.84% vs 90.91%) had a significant difference (P <0. 05);The PTEN protein positive rate between metastasis group and no lymph node metastasis group (46.88% vs 88.89%) had a significant difference (P <0. 05);According to clinical pathological stage, The PTEN expression positive rate betweenâ… +â…¡andâ…¢+â…£stage(88. 89% vs 45. 45%), the difference was significant difference (P<0. 05);With the increase in clinical stage, the differentiation of stomach cancer decreased, increased depth of invasion, lymph node metastasis, the PTEN positive rate decreased (P <0. 05). In addition, PTEN protein expression had no relation to the patients'age, sex, tumor size, location and other unrelated (P> 0. 05).2. PTEN gene methylation results:â‘ positive PCR product forl23bp.â‘¡The PTEN gene methylation rate of gastric cancer is 44.00 percent (22 of 50), The PTEN gene methylation rate of adjacent group is 5.00% (1 of 20). The PTEN gene methylation rate of normal gastric mucosa group is 0.00% (0 of 8), The PTEN gene methylation rate of gastric cancer was significantly higher than that of the adjacent group and the normal gastric mucosa group (p <0. 05).â‘¢the relationship between PTEN gene methylation and clinicopathological features of gastric cancer:The PTEN gene methylation rate between high school division group and poorly differentiated group(32. 26% vs 63.16%) had a significant difference (P <0.05); The PTEN gene methylation rate between metastasis group and no lymph node metastasis group(56. 25% vs 22. 22%)had a significant difference (P <0.05);According to clinical pathological stage, The PTEN gene methylation rate betweenâ… +â…¡andâ…¢+â…£stage(16. 67% vs 59. 38%), the difference was significant difference (P<0.05);With the increase in clinical stage, the differentiation of stomach cancer decreased, lymph node metastasis, the PTEN gene methylation rate increased (P <0.05). In addition, PTEN protein expression had no relation to the patients' age, sex,tumor size, location , invasion depth and othe unrelated (P> 0.05).3. PTEN protein expression and PTEN gene methylation: 9 cases are both positive of PTEN protein expression and gene methylation in gastric cancer, and 6 cases were negative. The former is positive while the latter is negative in 13 cases, the former is negative while the latter is negative in 22 cases . There is correlation between the positive rate of PTEN protein expression and PTEN gene methylation(Pr=0. 3594, P<0.05).Conclusion:There are a closely relationship between the PTEN protein expression levels and gastric cancer differentiation, clinical pathology stage, the depth of invasion and metastasis; There are a closely relationship between the PTEN gene promoter methylation and t gastric cancer differentiation, clinical pathology stage, the depth of invasion and metastasis; There is correlation between them in the development of gastric cancer PTEN can be used as one of the objective indicators which can evaluate the Pathological biological behavior of gastric cancer... |
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