Overexpression of Tbx3 is correlated with Epithelial-Mesenchymal Transition phenotype and predicts poor prognosis of colorectal cancer.

Abstract

AIMS: To investigate the clinical significance of Tbx3 in colorectal cancer (CRC) and the possible association between Tbx3 expression and Epithelial- Transition Mesenchymal (EMT) phenotype. METHODS: Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) and western blotting were employed to evaluate the expression of Tbx3 in 30 fresh CRC and matched normal tissues. Using immunochemistry, protein level of Tbx3 and EMT markers (E-cadherin and N-cadherin) were identified in 150 pairs of paraffin-embedded specimen. RESULTS: The results of qRT-PCR and western blotting showed that Tbx3 expression was higher in CRC tissues than in corresponding normal tissues. The statistical analysis based on immunohistochemical evaluation suggested that Tbx3 aberrant expression was significantly associated with tumor size (P=0.049), differentiation (P=0.032), invasion (P=0.019), lymph node metastasis (P=0.049) and TNM stage (P=0.018). Patients who displayed high expression of Tbx3 may achieve a poorer overall survival (OS) and disease-free survival (DFS), compared to those with low expression of Tbx3. This tendency was also observed in patients with intermediate levels of disease (II and III stage). The multivariate analysis indicated Tbx3 expression could independently predict the outcome of CRC patients. Interestingly, correlation analysis suggested Tbx3 expression was negatively correlated with E-cadherin expression, but positively correlated with N-cadherin expression. CONCLUSION: Tbx3 may promote CRC progression by involving EMT program and has the potential to be an effective prognostic predictor for CRC patients.