The Research On Expression Of PTEN And P27 Protein In Gastric Carcinoma And Its Significance

Objective:To investigate the expression of anti-oncogene PTEN and p27 which is presumed downstream target of PTEN in human gastric carcinoma and compared it with that of tumor-sideward mucosa and that of normal gastric tissues, to find the relationship between expre-ssion deletion of PTEN/P27 in gastric carcinoma and the pathological features of gastric carcinoma .Methodrlmmunohistochemistry was applied to examine the expression of PTEN and p27 in 36 cases of human gastric carcinoma, 10 cases of tumor-sideward mucosa and 8 cases of normal gastric. Results were compared with clinical pathologic parameter such as histology type,lymphatic metastasis and clinical stage.Result:1.Expression of PTEN protein:â‘ Positive immunostaining with the antibody was observed in the cytoplasm of cells.â‘¡61.11%(22 of 36)of cases had expression of PTEN in the tumor cells, and in 90.00% of cases (15 of 21) of the tumor-sideward mucosa,and 100% of cases(8 of 8)of the normal mucosa it were present. There was a significant positive correlation between gastric carcinoma specimens and normal mucosa specimens and tumor-sideward mucosa (P<0.05).â‘¢There was no significant diference between normal gastric group and tumorsideward mucosa group(P>0.05),but both were higher than cancer group(P<0.005).â‘£When PTEN expression was compared with clinicopathologi-cal, tumors with lymph node metastases (40.91%) had loss PTEN protein expression than those without metastasis (92.86%)(p<0.05).The PTEN expression between I+II and III+IV stage,the difference was significant (93.33% vs 38.10%)(P<0.05).The positive of PTEN in high and middle degrees of differentiation were significantly higher than that in low degree of differentiation(P<0.05).The positive rates of PTEN decreased with clinical stage,the poor differentiation, and lymph nodes metastasis (P<0.05).PTEN protein expression had no relation to the patients' age,sex,tumor size and location.2.Expression of p27 protein:â‘ Positive immunostaining with the antibody was observed in the nuclear.â‘¡63.89%(23 of 36)of cases had expression of p27 in the tumor cells, and in 90.00% of cases (9 of 10) of the tumor-sideward mucosa,and 100% of cases(8 of 8)of the normal mucosa it were present. There was a significant positive correlation between gastric carcinoma specimens and normal mucosa specimens and tumor-sideward mucosa (p<0.05).â‘¢There was no significant diference between normal gastric group and tumor-sideward mucosa group (P>0.05),but both were higher than cancer group(P<0.005).â‘£Tumors with lymph node metastases (45.45%) had loss p27 protein expression than those without metastasis (92.86%)(P<0.05).The p27 expression between I+II and III+IV stage,the difference was significant (93.33% vs 42.86%)(P<0.05). The positive of p27 in high and middle degrees of differentiation were significantly higher than that in low degree of differentiation(P<0.05).The positive rates of PTEN decreased with clinical stage, the poor differentiation,and lymph nodes metastasis(P<0.05).p27 protein expression had no relation to the patients' age,sex,tumor size and location.3. In gastric cancer positive expressive rates of PTEN and p27 were 61.11% and 63.89% respectively, without statistic diference (P>0.05),and correlated with each other (P<0.025). Pearson contingency of coefficient (p) =0.3838.Conclution: The abnormal expression of suppressor gene PTEN and p27 participate the malignant conversion process of the gastric mucosa cell and correlates with tumor stage, histological poor differentiation and lymph node metastasis; PTEN and p27 gene play Synergistic action in the occurrence and development of gastric carcinoma, the expression levels of the PTEN and p27 protein can be used to evaluate the pathologic biology behavior of gastric carcinoma.