Correlation between Smad3 gene and Smad7 gene in human gastric carcinoma and its clinical significance

Abstract:

Objective：To explore the expression of Smad3 gene and smad7 gene in human gastric carcinoma，their correlation and clini－cal significances. Methods：Totally 50 cases of gastric carcinoma with adjacent tissues and 10 cases of normal gastric tissues were collected in this study. Smad3 and Smad7 protein and mRNA expression in these samples was detected by immunohistochemistry and RT-PCR. Results：Smad3 protein expressions in gastric carcinoma tissue was significantly lower than that in the adjacent carcino－ma tissue（50.0% vs. 92.0%，P=0.000）. The expression was closely related with tumor stage（P=0.004） and tumor differentiation stage（P=0.030）. The expression was not related with patients’ age（?字2=0.439，P=0.508）or gender（?字2=0.117，P=0.733）. Positive rate of Smad7 protein expression in gastric carcinoma tissue was higher than that in adjacent carcinoma tissue（48.0% vs. 4.0%，P=0.000） with that in normal tissue being the lowest. The positive rate was closely related with tumor stage（P=0.009） and degree of differentiation（P=0.001）. Smad3 protein and Smad7 protein was found negative correlated in gastric carcinoma（r=-0.539，P=0.000）. Smad3 mRNA expression in carcinoma tissue was lower than that in adjacent carcinoma tissue（Z=7.84，P=0.000），but Smad7 mRNA expression in carcinoma tissue were higher than those in adjacent carcinoma tissue（Z=7.83，P=0.000）. Conclusions：Smad3 gene expression in car－cinoma tissue is decreased while Smad7 gene expression in cancer tissue is increased. Smad3 gene expression and Smad7 gene ex－pression are related with stage of gastric carcinoma and degree of differentiation. Correlated expression of these two genes plays cer－tain role in the occurrence and development of gastric carcinoma.