Abstract: Objective The purpose of this study was to investigate the effects of rapamycin on tumor growth and mTOR/4EBP1 signaling pathway in xenograft of esophageal squamous cell carcinoma (ESCC) EC9706 cells. The expressions of factors in mTOR/4EBP1 signaling pathway of the tumor tissues mentioned above were analyzed by RT-PCR and Western blotting, respectively. Results Both rapamycin and cisplatin significantly inhibited the growth of transplantable tumors compared to control group (P<0.05) and their combination had a stronger effect than that of them alone (P<0.01). The results of RT-PCR and Western blotting revealed that rapamycin significantly decreased the expression of mTOR and p-4EBP1 but increased the expression of 4EBP1. Conclusion Rapamycin inhibits the mTOR/4EBP1 signalling pathway, resulting in the growth inhibition of xenograft of EC9706 cells.

Key words: esophegeal squamous cell carcinoma, mTOR, 4EBP1, rapamycin