Expression of E-Cadherin and the PTEN Gene in Relation to Invasion and Metastasis of Gastric Carcinomas

OBJECTIVE To observe the expression of PTEN and E-Cadherin in gastric carcinomas (GCs), and to investigate the relationship between their expression and the pathology and prognosis of patients with GC.

METHODS The proposed markers were detected inmmunohistochemically by using the SABC method in 100 post-operated specimens of GC. The results were statically analyzed by the chi-square and log rank tests.

RESULTS Both E-Cadherin and PTEN proteins were expressed in non-cancerous mucosa. They were reduced or lost in GCs. The abnormal rate of expression of E-Cadherin was 42.0%. The decreased rate of expression in the diffuse-type GC (48.6%) was significantly higher than in the intestinal-type GC (26.7%, P<0.05). The abnormal expression of E-Cadherin closely correlated to the depth of invasion (P<0.05). The degree of loss of the PTEN protein was 59.0% in GCs. in the diffuse-type GC, the rate of loss of PTEN was (65.7%) which was significantly higher than that in the intestinal-type GC (43.3%, P<0.05). The rate of loss of PTEN (64.5%) in GCs with lymph node metastasis was significantly higher than that in GCs without metastasis (41.7%, P<0.05). The prognosis of patients with a loss of PTEN protein was worse than the patients with positive expression of PTEN (P=0.0066). E-Cadherin was normally expressed in 65.9% of GCs with positive expression of PTEN.

CONCLUSION The loss of E-Cadherin and PTEN markers correlated with infusion and metastasis of GC. The expression of PTEN showed a close relationship to the prognosis of patients. Detection of the 2 markers together aided in the correct prediction of the prognosis of the GC patients and provided information for clinical treatment.