Abstract
Increasing evidence showed that the substance P (SP)/neurokinin‑1 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. RT‑qPCR, CCK‑8, 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/tr‑NK1R system in human ESCC progression. The results revealed that both SP and tr‑NK1R 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 SP‑induced 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 tr‑NK1R indicated poor prognosis in ESCC, suggesting that aprepitant has a potential application in ESCC. To the best of our knowledge, high SP and tr‑NK1R 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.