Expression Of CDw75, Skp₂, PTEN Protein And Telomerase And Their Relationship In Gastric Carcinogensis

Objectives:We have aimed to study the expression of CDw75,Skp2,PTEN protein and telomerase in gastric cancer and to evaluate the significant correlation between their expression and cell cycle,to investigate their possible roles in the gastric carcinogenic mechanism,to provide evidence for prevention and therapy of gastric carcinoma using telomerase as a therapeutic target.Methods:Gastric tissue samples were obtained from 19 cases with chronic superficial gastritis(CSG),32 cases with intestinal metaplasia (IM),29 cases with dysplasia (Dys) and 50 cases with gastric carcinoma (GC). Expression of CDw75,Skp2 and PTEN protein were dectected by immuno -histochemistry(S-P method), telomerase by PCR-ELISA and cell cycle by flow cytometer(FCM).The data were analyzed by software SPSS 13.0, chi-square test was used to compare the difference between groups.A difference was considered significance if the p value was below 0.05.Results: Expression of CDw75,Skp2 and bcl-2 showed a gradually increasing tendency from CSG, IM, Dys to GC. Positive expression rates of CDw75,Skp2 and bcl-2 were 0,0 and 5.3% in CSG,0,3.1% and 31.3% in IM,6.9%,13.8% and 44.8% in Dys,46.0%,32.0% and 62.0% in GC respectively.But PTEN and p16 showed a gradually discreasing tendency from CSG,IM,Dys to GC. Positive expression rates of PTEN and p16 were 100% and 73.7% in CSG,93.8% and 65.6% in IM,55.2% and 41.4% in Dys,42.0% and 28.0% in GC respectively.There was a significant difference between GC and CSG, GC and IM in expression of the five proteins(P<0.05);but no significant difference in other groups(P>0.05).In histological, significant relations were found between the expression of CDw75 protein and TNM and lymph nodes metastasis (P<0.05); between the expression of Skp2 protein and TNM and histological type(P<0.05); between the expression of bcl-2 protein and tumor stage and lymph nodes metastasis (P<0.05); between the expression of PTEN protein and TNM, histological type and lymph nodes metastasis (P<0.05); between the expression of p16 protein and tumor stage,tumor invasion and lymph nodes metastasis (P<0.05).But no significant relations were found between them and year,sex,diameter of tumors and so on.Expression of telomerase showed a gradually increasing tendency from CSG,IM,Dys to GC. Positive expression rates of telomerase were 5.3% in CSG,0,18.8% in IM,51.7% in Dys,82.0% in GC respectively.There was no significant relations between telomerase and histological character of gastric carcinoma and bcl-2 protein(P<0.05).Growth-rate showed a gradually increasing tendency in gasteic carcinoma from fast-growth to no-growth,positively correlated with p16 protein.Conclusion: Expression of CDw75,Skp2 and bcl-2 showed a gradually increasing tendency in gastric carcinogensis,they may promote gastric carcinoma. But PTEN and p16 showed a gradually decreasing tendency, p16 promote cell proliferation. Expression of telomerase showed a gradually increasing tendency from CSG, IM, Dys to GC. There was no significant relations between telomerase and histological character of gastric carcinoma and bcl-2 protein. Expression levels of CDw75,Skp2,bcl-2,PTEN and p16 can be regarded as a marker for evaluating malignant degree of GC, lymph node metastasis and prognosis.