The Expression And Clinical Significance Of Complement Regulatory Proteins CD46 And CD59 In Human Gastric Cancer And Adjacent Tissues

Objective: To investigate the expression and significance of CD46 (membrane cofactor protein,MCP)And CD59 (protectin) in human gastric cancer and adjacent tissues, and explore theirs roles and correlations in the occurrence,development,invasion and metastasis of gastric cancer.Methods: To be selected 33 paraffin-embedded blocks of gastric cancer operative specimens in the gastrointestinal surgery of the first affiliated hospital of Guangxi Medical University from January 2008 to August 2008, and 20 specimens of adjacent tissue to be sleceted for control group.The immunohistochemical staining method (ultra-sensitive-SP) was chosen to detect the expression and distribution of CD46 and CD59 in both groups. Compared the staining results of gastric cancer tissues with paracancerous tissues. It was scored by couple score semi-quantitative mehtod:(1) positive rate of target cells<5% was 0, 5%-25% was 1, 26%-50% was 2, >50% was 3;(2) Depth of staining reaction scored 0~3, staining depth was classed according to the color reaction of most cells,not colouring was 0,light brown was 1, brownish yellow was 2,deep brownish yellow was 3.The scoring sum was divided into four grades according to the above two items,including: negative (-) was 0, weak positive (+) was 1~3, positive (++) was 4~6, intensively positive (+++)was 9. All data were analysed with the SPSS 13.0 statistical software.Result: The expression of CD46 and CD59 was found in both gastric carcinoma tissues and adjacent tissues.In 33 gastric carcinoma tissues, positive rate of CD46 was 87.87%(29/33), and negatice staining(-) was 12.12% ( 4/33 ) ,weak positive staining(+) was占12.12% (4/33),moderate positive staining(++)was21.21%(7/33),intensively positive staining(+++)was 54.54% ( 18/33 ) .In 20 adjacent tissues,positive rate of CD46 was 40%( 8/20),negative staining(-)was 60%(12/20),weak positive staining(+)was 30%(6/20),moderate positice staining(++)was 10%(2/20),intensively positice staining(+++)was 0.00%(0/20).There was significant difference between the two groups by statistics evaluation (P<0.05).In 33 gastric carcinoma patients, positive rate of CD59 was 81.81%(27/33), with negative staining (-) was 18.18%(6/33), weak positive staining (+) was 18.18%(6/33), moderate positive staining (++) was 39.39%(13/33), intensively positive staining (+++) was 24.24%(8/33). In 20 normal gastric mucosa tissues, positive rate of CD59 was 45.00%(9/20),with negative staining (-) was 55.00%(11/20), weak positive staining (+) was 30.00%(6/20), moderate positive staining (++) was 10.00%(2/20), intensively positive staining (+++) was 5.00%(1/20).There was significant difference between the two groups statistically(P<0.05).The expression of CD46Ⅲ+Ⅵgroup was higher thanⅠ+Ⅱgroup(P<0.05)in TNM stages of gastric cancer group, there was no significant difference between the two groups in the expression of CD59(P>0.05); the expression of CD46 was more intense with incresease invasive depth(p=0.021) , there was no significant difference between the two groups statistically(P>0.05);the expression of CD46 was more intense than the well-moderately differentiated group in histological poorly differentiated group of gastric cancer group;and no statistical difference was found in the two groups in the expression of CD59(P>0.05); and the gastric cancer group was grouping by the age,the gender,lymph node metastasis and tumor size, there was no significant difference between CD46 and CD59 statistically(P>0.05). No correlation was found between the expression of CD46 and CD59 in gastric carcinoma tissues(P>0.05).Conclusion: Through the analysis and study of the protein expression of CD46 and CD59 in 33 gastric cancer pathologic slices, we come to our own conclusion:1,The rise of CD46 and CD59 expression maybe relate to development on gastric cancer.and maybe a possible mechanisms of gastric carcinoma eascaping immunologic surveillance and immunity attack.2,The expression of CD46 was associated with the pathologic differentiation degree and invasive depth and TNM stages of gastric cancer.which suggests that the intense staining of CD46 could be extremely important to tumor occurrence,development,invasion and metastasis.3,There is no correlation between clinicopathologic factors and the positive intensity of CD59;The expression has no correlation between CD46 and CD59 .4,CRPs could be important molecules for early diagnosis of tumor,criterion of tumor prognosis and molecule targeted therapy.