Expression and Effects of Smad_4 and Smad_7 in Human Glioma

Objective To investigate the expression of Smad 4 and Smad 7 proteins, which are intracellular signaling molecules of transforming growth factor-β family in human glioma.Methods The expression levels of Smad 4 and Smad 7 in 30 cases of human glioma and 8 cases of normal brain tissue specimen were detected by immunohistochemical technics.Results In normal brain tissue, groupⅠ,Ⅱ and Ⅲ, Ⅳ, the positive expression levels of Smad 4 was 44.80 ± 16.19 , 25.81 ± 9.48 , 6.73 ± 3.71 respectively, and Smad 7 was 6.69 ± 3.86 , 18.22 ± 7.84 , 41.95 ± 17.27 respectively. The difference were significant ( P 0.05 ). The expression of Smad 4 was lower in glioma than normal tissue. However, the expression of Smad 7 was positively correlated with the tumor grade. Smad 4 and Smad 7 were negative correlation( r = -0.82 ). Conclusion These finding suggested that Smad 7 play an important role during the malignant behaviors of glioma. Smad 4 could be a good tumor suppressor gene of glioma.