Tazarotene-induced gene 2 is associated with poor survival in non-small cell lung cancer.

The aim of the present study was to investigate the expression of tazarotene-induced gene 2 (TIG2) and evaluate the clinicopathological variables and prognostic value for non-small cell lung cancer (NSCLC) patients. Reverse transcription-polymerase chain reaction and western blotting were utilized to detect TIG2 expression in NSCLC specimens and adjacent noncancerous tissue. Furthermore, the present study investigated the protein expression and the clinicopathological significance of TIG2 in 98 paraffin-embedded NSCLC samples by using immunohistochemistry. The results of the present study demonstrated that the expression of TIG2 mRNA (P=0.003) and protein (P=0.0024) was significantly reduced in NSCLC compared with corresponding noncancerous tissue. TIG2 protein expression in NSCLC was significantly associated with lymph node metastasis (P=0.006), Tumor-Node-Metastasis stage (P=0.021) and degree of differentiation (P=0.025). The Kaplan-Meier method and log-rank test revealed that high TIG2 expression was significantly associated with increased survival of NSCLC patients (P=0.003). Multivariate analysis revealed that TIG2 expression was an independent prognostic factor of the overall survival of NSCLC patients. Decreased expression of TIG2 may be useful as a biomarker for poor prognosis in NSCLC carcinogenesis and may act as a target for gene therapy for the treatment of NSCLC patients.