Overexpression of T-box Transcription Factor 5 (TBX5) Inhibits Proliferation and Invasion in Non-Small Cell Lung Carcinoma Cells.

T-box transcription factor 5 (TBX5), a member of the conserved T-box transcription factor family that functions in organogenesis and embryogenesis, has recently been identified as a critical player in cancer development. The aim of this study was to determine the role of TBX5 in non-small cell lung carcinoma (NSCLC). Immunohistochemistry was used to detect the correlation between levels of TBX5 and clinicopathological features of NSCLC patients in tissue microarray. Expression of TBX5 in NSCLC tissues and cell lines was evaluated by quantitative PCR and Western blot. The role of TBX5 in regulating proliferation, colony formation, invasion, and apoptosis of NSCLC cells was evaluated in vitro. Finally, a tumorigenicity assay was performed to determine the effect of TBX5 on tumor growth in vivo. The levels of TBX5 in NSCLC tissues were significantly correlated with the TNM stage (p = 0.016), histopathologic type (p = 0.029), and lymph node status (p = 0.035) of NSCLC. TBX5 overexpression markedly suppressed in vitro NSCLC cell proliferation, colony formation, and invasion and induced apoptosis. In vivo tumor growth was significantly suppressed by TBX5. TBX5 has a tumor-suppressing effect in NSCLC and may serve as a therapeutic target for diagnoses and treatment of NSCLC.