Expression Of Cyclooxygenase-2 And P27 Protein In Gastric Carcinoma And Its Clinical Significance

[Aims] To observe the expression of cyclooxygenase-2 (COX-2) and P27 protein in gastric precancerosis and gastric carcinoma and to explore the relationship between the expression of these two proteins and the development of precancerous lesion and gastric carcinoma.[Methods] The expression of Cox-2 and the p27 protein in precancerous lesion and gastric carcinoma was examined immunohistochemically by using Power the Vision two steps method. Known (prepared) slices of gastric precancerosis and gastric carcinoma were used as positive controls. Normal rabbit or mouse sera and normal gastric mucous membrane were used as negative controls.[Results] 1.Cox-2 expression was positive in 47 of the 65(72.31%) gastric carcinoma examples, 4 of the 30 (13.33%)chronic atrophic gastritis examples, 7 of the 19 (36.84%)intestine metaplasia of gastric mucous membrane examples, 9 of the 18(50%)atypical proliferation of gastric mucous membrane examples, and only 1 of the 14(7.14%)normal gastric mucous membrane examples. 2. P27 expression was positive in 27 of the 65(41.54%) gastric carcinoma examples, 25 of the 30(83.33%)chronic atrophic gastritis examples, 13 of the 19(68.42%)intestine metaplasia of gastric mucous membrane examples, 8 of the 18(44.44%)atypical proliferation of gastric mucous membrane examples, and all of the 14(100%)normal gastric mucous membrane examples. 3. The positive rate of Cox-2 protein expression had a tendency to increase progressively and gradually from normal gastric mucous membrane to chronic atrophic gastritis to intestine metaplasia to atypical proliferation and to gastric carcinoma. However, the positive rate of p27 protein expression had a tendency to decrease progressively and gradually from normal gastric mucous membrane to chronic atrophic gastritis to intestine metaplasia to atypical proliferation and to gastric carcinoma The expression rate of Cox-2 and p27 protein had no significance difference (P>0.05) between gastric carcinoma group and the group of atypical proliferation of gastric mucous membrane. However, the expression rate of Cox-2 and p27 protein had a significance difference (P<0.05) between gastric carcinoma group and all other groups.4. The positive rate of Cox-2 protein expression was significantly related to gastric carcinoma's infiltration depth, the lymph node metastasis and clinical staging(P<0.05), but have no obviously relation with patient's sex, the age, the tumor size and position, and the degree of differentiation (P>0.05). 5. The positive rate of p27 protein expression was significantly related to gastric carcinoma's infiltration depth, the lymph node metastasis and clinical staging (P<0.05), but have no obviously relation with patient's sex, the age, the tumor size and position, and the degree of differentiation (P>0.05).6. Cox-2 expression and p27 expression assumed a remarkable inverse correlation in the gastric carcinomas (rs= -0.6644, u= -5.3152, P<0.001)[Conclusion] 1. The Cox-2 expression rate in gastric carcinoma tissue is significantly higher than that of normal gastric mucous membrane, indicating that Cox-2 expression is related to gastric carcinomas development and Cox-2 is one of gastric carcinoma's specificity targets. 2.Cox-2 protein expression has a tendency to increase progressively and gradually from normal gastric mucous membrane to chronic atrophic gastritis to intestine metaplasia to atypical proliferation and to gastric carcinoma, showing that Cox-2 maybe the molecular marker of the development from chronic atrophic gastritis to the gastric carcinoma. 3. The Cox-2 protein expression is positively related to the infiltration depth, lymph node metastasis, and clinical stages, suggesting that Cox-2 protein expression level is closely related to the invasion, metastasis, and prognosis of gastric carcinoma. 4. The p27 protein expression rate in gastric carcinoma tissue is significantly lower than that of normal gastric mucous membrane, suggesting that the decrease of p27 protein level is closely related to the development of gastric carcinoma. 5. The p27 protein expression has a declining tendency from normal gastric mucous membrane to gastric carcinoma, assuming that p27 protein maybe the factor to promote the development from gastric mucous membrane to gastric carcinoma. 6. p27 protein expression is negatively related to the degree of differentiation, depth of infiltration, lymph node metastasis, and clinical stages, suggesting that p27 protein can inhibit cell multiplication and ontogenesis and promote normal differentiation. 7. Cox-2 protein expression and p27 protein expression in the gastric carcinoma are negatively related significantly, suggesting that Cox-2 activity may promote p27 protein expression...