Thymosin beta(4) is a novel potential prognostic marker in gastrointestinal stromal tumors

Abstract

Thymosin beta-4 (T beta 4) is a major actin-sequestering molecule that contributes to cell growth, differentiation, motility, survival, mitosis and angiogenesis. It is overexpressed in certain type of carcinoma and fibrosarcoma cell lines and is associated with metastatic potential. The aim of this study was to investigate the relationship between T beta 4 expression and clinicopathologic features and VEGF status in gastrointestinal stromal tumors (GISTs). Retrospectively, 60 GISTs were re-examined and immunohistochemistry for T beta 4 and VEGF was performed. Increased expression of T beta 4 and VEGF was observed in 26 (43.3%) and in 19 (31.6%) of the tumors, respectively. T beta 4 expression was positively correlated with VEGF expression (p similar to<similar to 0.01). T beta 4 and VEGF expression were significantly associated with tumor size (p similar to=similar to 0.00 and p similar to=similar to 0.02, respectively) and high mitosis (p similar to=similar to 0.03 and p similar to=similar to 0.00, respectively). Although T beta 4 expression was positively associated with pleomorphism (p similar to=similar to 0.01), VEGF expression was positively associated with necrosis (p similar to=similar to 0.03). T beta 4 expression was related with local recurrence and/or metastasis (p similar to=similar to 0.03), but VEGF expression was not (p similar to=similar to 0.12). We firstly demonstrate the presence of T beta 4 protein in GISTs. Our study reveals that increased expression of T beta 4 could be considered as an indicator of aggressive behavior of tumor.