Expression of special AT rich sequence binding protein-1 in bladder transitional cell carcinoma and its correlation with epithelial-mesenchymal transition

Abstract

Objective To investigate the expression of special AT rich sequence binding protein-1 (SATB1) and genes involved in epithelial-mesenchymal transition (EMT) in bladder transitional cell carcinoma (BTCC),and to explore the relationship between SATB1 and EMT-related genes with with clinieopathologic features of BTCC.Methods Immunohistochemisty and real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) were used to detect the expression of SATB1,E-cadherin and Snail in 82 cases of BTCC tissues.For each specimen,the cancerous tissue,peri-cancer tissue and its remote normal mueosa were analyzed and compared Results The immunohistochemisty revealed that the expression of SATB1 and Snail in BTCC was significantly higher than that in periearcinomatous tissues and normal bladder tissues (P ＜ 0.05).Inversely,the expression of E-cadherin was significantly lower in BTCC than that in pericarcinonatous tissues and normal bladder tissues (P ＜ 0.05).The positive expression rate of SATB1,E-cadherin and Snail was 90.24％,18.29％ and 80.49％ for BTCC,17.07％,79.27％ and 30.49％ for pericarcinomatouse tissues,and 8.54％,91.46％ and 15.85％ for normal bladder tissues,respectively.The positive expression rate of SATB1,E-cadherin and Snail in the pathological grades 1,2and3 was 76.19％,23.81％ and 61.90％,92.00％,20.00％ and 76.00％,and 97.22％,13.89％and 94.44％ respectively.There were significant differences in each group (P ＜ 0.05).The positive expression rate of SATB1 and Snail in the clinical stages of Tis-T1 was lower than that in the stages of T2-T4 (78.00％ vs.97.96％,P ＜ 0.05 ; 66.67％ vs.89.80％,P ＜ 0.05).Inversely,the positive expression rate of E-cadherin was significantly higher in the clinical stages of Tis-T1 than that in the stages of T2-T4 (24.24％ vs.14.29％,P ＜ 0.05).Moreover,with the advancing grades and appearances of lymph node metastasis,the expression levels of SATB1 and Snail were increased gradually,but in contrast,the expression levels of E-cadherin decreased gradually.There were significant differences in each group (P ＜0.05).The results of RT-qPCR data were agreed to those of the immunohistochemisty.Conclusion The excessive expression of SATB1 and Snail,and low expression of E-cadherin were closely related to the pathology,clinical stages and metastasis of lymph node of the cancer.SATB1 expression was inversely correlated to E-cadherin,but positively to Snail.SATB1 may regulate the invasion and metastasis of BTCC through inducing EMT.The over expression of SATB1 may play an important role in carcinogenesis and progress of BTCC. Key words: Bladder transitional cell carcinoma; Epithelial-mesenchymal transition; Special AT rich sequence binding protein-1 ; E-cadherin