CD51 Intracellular Domain Promotes Cancer Cell Neurotropism through Interacting with Transcription Factor NR4A3 in Colorectal Cancer

SIMPLE SUMMARY: Perineural invasion is an important cause of postoperative recurrence and metastasis of colorectal cancer, but the mechanisms of perineural invasion are not well characterized. Meanwhile, there is no targeted therapy for perineural invasion in the current treatment of colorectal cancer. In this study, we first show that CD51 can be cleaved by γ-secretase to generate an intracellular domain that promotes perineural invasion. More importantly, we have demonstrated for the first time that pharmacological inhibition of γ-secretase can help prevent perineural invasion in colorectal cancer. ABSTRACT: The abundant nervous system in intestine provides the basis for perineural invasion (PNI) of colorectal cancer (CRC). PNI is defined as the invasion of the nerves by cancer cells. Although PNI is already known to be an independent prognostic factor in CRC, the molecular mechanism underlying PNI remains obscure. In this study, we first demonstrated that CD51 could promote the neurotropism of tumor cells through cleavage with γ-secretase to generate an intracellular domain (ICD). Mechanistically, ICD of CD51 could bind to the transcription factor NR4A3, and act as a coactivator to promote the expression of downstream effectors, such as NTRK1, NTRK3, and SEMA3E. Pharmacological inhibition of γ-secretase impedes PNI mediated by CD51 in CRC both in vitro and in vivo and may become a potential therapeutic target for PNI in CRC.