Clinical significance of β-catenin ectopic expression and epithelial-mesenchymal transition in synovial sarcoma

MEIER Tuhetamishi; WANG Ning; LIANG Wei-hua; QI Yan

doi:10.3969/j.issn.1007-8096.2025.02.005

Abstract：Objective To detect the expression of β-catenin in synovial sarcoma(SS),and to analyze the correlation between β-catenin and clinicopathological parameters and prognosis of SS patients.Methods The paraffin-embedded tissues from surgical archives of 29 patients with SS were collected.The expression of β-catenin,TGF-β1 pathway protein and epithelial-mesenchymal transition(EMT)associated protein was detected by immunohistochemistry EnVision method.Results The positive rates of β-catenin in the cytoplasm/membrane of biphasic synovial sarcoma(BSS)epithelial area and spindle cell area were 100％and 71％,respectively,and the expression of β-catenin was statistically significant(P=0.00)in these two cellular components.The expression of β-catenin in the nucleus of 29 cases of SS was correlated with tumor growth site and FNCLCC grade(P=0.03,P=0.02),which suggested that the nuclear expression of β-catenin was related to histological grading.Univariate Cox regression analysis showed that TNM stage Ⅲ-Ⅳ(P=0.015),high expression of β-catenin nucleus(P=0.025)and tumor metastasis(P=0.011)were associated with overall survival of SS patients.Multivariate Cox regression analys showed that the expression of β-catenin nucleus was an independent risk factor influencing overall survival in SS patients(P=0.019).The expression of β-catenin in the BSS spindle cell nucleus was correlated with the expression of TGF-β1 and snail in the BSS spindle cell components(P=0.04,P=0.01),expression in cytoplasm/cell membrane of BSS epithelial components was correlated with TGF-β1(P=0.04).The expression of β-catenin in the cytoplasm and/or cell membrane of MFSS was significantly correlated with that of N-cadherin in monophasic fibrous synovial sarcoma(MFSS)(P=0.02).Conclusion β-catenin is involved in the differentiation of both epithelioid and mesenchymal components through the EMT process of SS,regulated by TGF-β signal passway.