TGIF1 splicing variant 8 is overexpressed in oral squamous cell carcinoma and is related to pathologic and clinical behavior

Abstract

Objective: Possible differences in splicing variants of TGIF1 in oral squamous cell carcinoma (OSCC) have not yet been reported. This study analyzed the expression levels of different splicing variants of the TGIF1 gene in OSCC compared with nontumoral epithelium (NT) and the relationship with clinical-pathologic features of tumors. Study Design: Forty-eight frozen samples of OSCC and 17 of NT were analyzed using quantitative reverse transcription polymerase chain reaction. Results: TGIF1v2 and v8 are overexpressed in OSCC, whereas TGIF1v5 is underexpressed when compared with NT. Low TGIF1v8 expression was correlated with lower cellular differentiation, positive blood vascular invasion, advanced pathologic stage, and positive vascular lymphatic invasion of OSCC. TGIF1v8 is also related to overall survival over time, with lower values associated with an increased risk of cancer-related death. Conclusions: These data suggest that alternative splicing of TGIF1 is deregulated in OSCC, with overexpression of some splicing variants, especially TGIF1v8, which is associated with advanced stages of OSCC.