Aprepitant inhibits the progression of esophageal squamous cancer by blocking the truncated neurokinin­1 receptor.

Increasing evidence showed that the substance P (SP)/neurokinin­1 receptor (NK1R) complex is involved in the development of several cancers. However, little is known about the mechanisms by which SP/NK1R complex plays a role in esophageal squamous cell carcinoma (ESCC) progression. RT­qPCR, CCK­8, Transwell, western blotting, immunohistochemical, immunofluorescence, ELISA and analysis of apoptosis were employed in the present study. It was aimed to investigate the function and therapeutic potential of the SP/tr­NK1R system in human ESCC progression. The results revealed that both SP and tr­NK1R were highly expressed in ESCC cell lines and specimens. In ESCC tissues, SP was mainly derived from ESCC cells and M2 macrophages. The NK1R antagonist aprepitant inhibited the SP­induced proliferation of human ESCC cell lines. Aprepitant inhibited cell migration and invasion and induced apoptosis of ESCC cells by downregulating the PI3K/AKT/mTOR signaling pathways. Animal experiments revealed that aprepitant inhibited tumor progression of ESCC in xenograft mice. In conclusion, high expression of SP plus tr­NK1R indicated poor prognosis in ESCC, suggesting that aprepitant has a potential application in ESCC. To the best of our knowledge, high SP and tr­NK1R expression in ESCC cell lines was reported for the first time in the present study. These findings provided evidence for a novel therapeutic strategy for patients with ESCC.