Potential therapeutic strategy for oral squamous cell carcinoma by ErbB3-binding protein 1 gene transfer

An ErbB3-binding protein 1 (Ebp1), was shown to be a potent tumor suppressor in breast and prostate cancer cells. We hypothesized that the inhibitory properties of the Ebp1 gene could be beneficial if ectopically expressed in oral squamous cell carcinoma (OSCC) cells. One OSCC cell line Tca8113 was stably transfected with the complete Ebp1 cDNA or the vector control pcDNA3.1. The inhibitory effect was evaluated using in vitro proliferation assay, cell cycle distribution and anchorage-independent growth in soft agar as well as in vivo tumorigenicity. Stable gene transfer was verified by Western Blot analysis and reverse transcription RT-PCR. Following transfection of Ebp1, a significant reduction in cell proliferation and anchorage-independent growth in soft agar were observed. Ectopic expression of Ebp1 led to a change in cell cycle profile and most importantly, a strong decrease in tumorigenicity of human OSCC cell line in a xenograft mouse model. Ectopic expression of Ebp1 mediates multiple antitumor activities against OSCC, suggesting a potential of Ebp1-based novel therapy for clinical OSCC treatment.