Expression of Smad2 gene in human glioma with different pathologic grade proliferation and its clinical significance

Abstract

Objective To investigate the expressions of Smad2 gene in human gliomas,and to explore whether the expression of Smad2 associate with pathologic grading and the expression of Ki - 67.Methods The expression of Smad2 mRNA was examined by reverse transcription polymerase chain reaction ( RT - PCR) and its protein was detected by SP immunohistochemistry in 80 human glioma specimens.The results were analyzed with statistic methods.The comparison of Kapan - Meier survival curves of overall survival time according to Smad2 expression was analyzed by log - rank method.Results ( 1 ) The expression of Smad2 protein increased in high grade glioma ( Ⅲ and Ⅳ ),while it decreased in low grade glioma ( Ⅱ ) significantly ( P ＜ 0.001 ).( 2 ) The level of Smad2 mRNA transcription increased in high grade glioma,while it decreased in low grade glioma ( P ＜ 0.05).(3) The expressions of Smad2 and Ki -67 had positive correlation ( r =0.812,P ＜0.001 ).(4) According to integrated optical density of Smad2,all patients were divided into two groups,Low Smad2 and High Smad2.Overall survival time was significantly different between the two groups ( P ＜ 0.05 ).Conclusion The expression of Smad2 protein and the level of mRNA transcription increases significantly in malignant gliomas.Detecting Smad2 protein or mRNA in human glioma can be used for judging the malignancy degree and the prognosis. Key words: Glioma; Smad2 ; Immunohistochemistry; RT - PCR; Prognosis