Ectopically Expressed IBP Promotes Cell Proliferation in Oral Squamous Cell Carcinoma

Abstract

IFN regulatory factor 4 binding protein (IBP) has been shown to play an important role in the progression of malignant tumors such as breast cancer cells, but its function in oral squamous cell carcinoma (OSCC) remains unclear. We found that IBP ectopically expressed in some OSCC specimens but not in normal oral mucosa epithelium tissues. IBP expression was significantly correlated with tumor size, differentiation, clinical stage, and distant metastasis. Furthermore, IBP markedly promoted OSCC cell proliferation, shortened the G1 interval in the cell cycle, and increased cyclin D1 expression. These findings suggest that IBP may be a potential therapeutic target for OSCC.

Keywords: :

• Interferon regulatory factor 4 (IRF-4) binding protein (IBP)
• Oral squamous cell carcinoma (OSCC)
• Proliferation
• Cell cycle

ACKNOWLEDGMENTS

We thank Dr. Alessandra B. Pernis (Columbia University, NY, USA) for the pEGFP-C1-IBP plasmid. We also thank Liting Wang and Wei Sun (Central Laboratories, TMMU, China) for their technical assistance with laser scanning confocal microscopy. This project was supported by grants from the National Natural Science Foundation of China (grant nos. 30901458, 81272909 and 81072154), the grant from the Chongqing Science & Technology Commission, Chongqing, P.R. China (no. CSTC2009BB5027), and the grant from the Third Military Medical University (no. 2009XHG06).