Expression Of Snail And Twist In Synovial Sarcoma And Their Relation With Epithelial Differentiation

Object:To detect the expression of Snail and Twist in human synovial sarcoma tissue and analyze their expression distribution in different clinicopathological parametres and the impact on metastasis of synovial sarcoma and the survival of the patients. To explore the possible mechanism of Snail and Twist on metastasis of synovial sarcoma.Method:Histopathological and immunohistochemical staining methods were performed to evaluate the expression of Twist, Snail in 133 cases tissue specimens cut from patients with synovial sarcoma in Tianjin Cancer Hospital between 1973.1-2005.1. In addition, clinicopathological characteristics and survival were compared with the expression of Twist and Snail.Real-time PCR (real-time reverse transcription-polymerase chain reaction) were performed to detect the mRNA expression of Snail and Twist in fresh synovial sarcoma specimen, reverse transcription-polymerase chain reaction were performed to detet subgroup of fusion gene, analyze mRNA expression of Snail and Twist in different fusion gene subgroup.Using immunohistochemical staining to detect the relationship of expression of epithelial markers CK, EMA and E-cadherin to expression of Snail and Twist, explore the effect of Snail and Twist on synovial sarcoma metastasis.Result:Snail located at the nucleus in synovial sarcoma tissue and the ratio of high expression was 65.7%(82/133) and that expression of Snail was related with histolgical subtype(P=0.006). Twist located at the cytoplasm, and the ratio of high expression was 41.4%(55/133). The expression of Twist was related with histolgical subtype(P=0.002), AJCC stage(P=0.045) between the expression of Twist and that of Snail (rs=0.191, P=0.027)Unvariable analyze showed that patients with high expression of twist had shorter survival time than that of those with low expression of them(P=0.03) and the expressions of Twist and Snail had related with shorter metastasis-free survival time(P=0.001 and P=0.032).The result of RT-PCR and immunohistochemical staining indicated that Snail and Twist expression higher in SYT-SSX1 fusion gene subgroup than in SYT-SSX2(P=0.009, P=0.041), and the expression of Twist was statistically different in SYT-SSX1 and SYT-SSX2 (P<0.05). Expression of E-cadherin was higher in the cases which was positive for Snail than those negative; Expression of E-cadherin was statistically higher in the cases which was positive for Twist than those negative (P<0.05)Conclusion:1 The expression of Twist and Snail exists in synovial sarcoma.2 The expressions of Twist mRNA and Protein in SYT-SSX1 synovial sarcoma were higher than SYT-SSX2 synovial sarcoma, which indicate SYT-SSX might regulate the expression of Twist.3 Twist and Snail may be promote the metastasis of synovial sarcoma and impact the survival of synovial sarcoma survival4 Twist and Snail might regulate the metastasis of synovial sarcoma by down-regulating E-cadherin.