The Expression Of EphA2 And E-cadherin In Gastric Cancer And Their Relation With Clinicopathological Features

BACKGROUND: Gastric cancer is one of the most common malignancies in the world. Invasion, metastasis and recurrence are the main causes of death in gastric cancer patients and the key factors affecting clinical treatment and prognosis. It is importance of studying about mechanism of development, invasion and metastasis. EphA2 receptor is one member of receptor tyrosine kinases. The interactions between Eph receptors and ligands can induce two-ways signal transduction processes and a series of biological effects. E-cadherin (E-cad), one class of cell adhesion molecules in cadherin family, distributes in the epithelial cells widely. E-cad plays an important role in maintaining the epithelial cell integrity and polarity.Lack of E-cad's expression leads to the decline of cell adhesion ability and the enhancement of decentralization.OBJECTIVE:To investigate the correlation of EphA2 and E-cadherin expression with the clinicopathological features in human gastric cancer.And to explore the relevance of EphA2 and E-cadherin.METHODS:The expression of EphA2 and E-cadherin was examined by using immunohistochemistry (SP method) in normal stomach mucosa, paratumoral tissues and gastric cancer tissues. The relationship between their expression and clinicopathological features was statistically analyzed in gastric cancer.The relevance of EphA2 and E-cadherin was also evaluated.RESULTS:1. The positive rate of EphA2 expression was 64.8% in gastric cancer tissues, in paratumoral tissues and normal gastric mucosa tissues was 38.9% and 25% respectively. The expression of EphA2 in cancer tissues was significantly higher than that in the paratumoral tissues and normal stomach mucosa tissues (P＜0.01);2. The positive rate of E-cad expression was 37.0% in gastric cancer tissues, in paratumoral tissues and normal gastric mucosa tissues was 85.2% and 100% respectively. The expression of E-cad in cancer tissues was significantly lower than that in the paratumoral tissues and normal stomach mucosa tissues (P＜0.01);3. The expression of EphA2 in gastric cancer tissues was not statistically related with the age, sex, tumor size and the degree of tumor differentiation. High EphA2 expression was significantly correlated with depth of tumor invasion (P=0.018), UICC TNM stage of tumor (P=0.041) and lymph node metastasis (P=0.035);4. The expression of E-cad in gastric cancer tissues was not statistically related with the age, sex, and tumor size. Descending or loss E-cad expression was significantly correlated with depth of tumor invasion (P=0.030),degree of tumor differentiation (P=0.047),UICC TNM stage of tumor (P=0.020) and lymph node metastasis (P=0.015);5. In gastric cancer tissues, the expression of EphA2 protein was inversely correlated with that of E-cad (r=—0.602, P＜0.001).CONCLUSIONS:1.The expression of EphA2 was significantly increased in gastric cancer tissues. High EphA2 expression was significantly associated with the depth of cancer invasion,tumor UICC TNM stage and lymph node metastasis, but not related with the age, sex, tumor size and the degree of tumor differentiation.2. The expression of E-cad was significantly reduced in gastric cancer tissues. Descending E-cad expression was significantly associated with the depth of cancer invasion, degree of tumor differentiation,tumor UICC TNM stage and lymph node metastasis,but not related with the age, sex and tumor size.3. In gastric cancer tissues,EphA2 and E-cadherin protein expression were negatively correlated.