Expression of growth arrest and DNA damage inducible 45a in human oral squamous cell carcinoma is associated with tumor progression and clinical outcome

Abstract

The aim of this study was to examine the growth arrest and DNA damage-inducible (Gadd45a) expression and its role in tumor progression, invasion and metastasis in oral squamous cell carcinoma (OSCC). Growth arrest and DNA damage-inducible 45a distribution was detected by immunohistochemistry in tumor sections of 106 patients with primary OSCC and sections of adjacent pericancerous tissues from 60 patients among the 106. The association between the Gadd45a expression and clinical prognosis of OSCC were performed by statistical analysis. Gadd45a gene knockdown was performed in Tca8113 cells by small interfering ribonucleic acid treatment and its effects on cell cycle, and migration were detected by Flow Cytometric (Becton Dickinson, USA) and transwell chamber assay respectively. The results showed that Gadd45a was redistributed to cytoplasm in poorly differentiated carcinoma from its nucleus location in normal tissue (P < 0.05). The expression of Gadd45a was significantly associated with lymph node metastasis, tumor stage and tumor histological grade (P < 0.05). Knockdown of Gadd45a gene abolished the G2/M arrest and increased migrating ability of Tca8113 cell (P < 0.05). The results indicate that Gadd45a play an important role in OSCC metastasis by affecting the bioactivity of the tumor cells, and its distribution may serve for the prediction of clinical outcome of OSCC.