Cancer-induced nerve injury promotes resistance to anti-PD-1 therapy [Spatial Transcriptomics]

Peri-neural invasion (PNI) is a well-established poor prognostic factor in multiple cancer types. However, the mechanisms driving the PNI's detrimental clinical effect remain elusive. Here, we provide clinical and mechanistic insights into PNI and cancer-induced injury of tumor-associated nerves (TANs) and their role in resistance to anti-PD-1 therapy. Our work demonstrates that poor response to anti-PD-1 therapy in cutaneous squamous cell carcinoma (cSCC), melanoma, and gastric cancer is associated with PNI and TANs injury. Ultrastructural electron microscopy analysis reveals that direct contact between cancer cells and nerve fibers leads to cancer-induced nerve injury (CINI) via myelin degradation. Injured neurons respond by autonomously initiating an interleukin (IL)-6 and interferon (IFN) type I inflammatory response. This inflammatory response alters the immune activity in the peri-neural niche in melanoma, cSCC, and pancreatic adenocarcinoma, leading to an immuno-suppressive activity aimed at nerve healing and regeneration. As the tumor grows, the CINI burden increases, the inflammatory signal within the niche becomes chronic, and eventually skews the general immune tone within the tumor microenvironment to a suppressive and exhaustive state. The CINI-driven anti-PD-1 resistance can be reversed by targeting multiple steps in the CINI signaling process: denervating the tumor, conditional knockout of the transcription factor mediating the injury signal within neurons (cKO-Atf3), knockout of the IFN-a receptor signaling (Ifnar1-/-), or by combining anti-PD-1 and anti-IL-6-receptor blockade. Our findings demonstrate the direct immuno-regulatory roles of TANs and their therapeutic potential. Overall design: Cutaneous squamous cell carcinoma samples were processed for spatial transcriptome analyses using the Visium (10X Genomics. We conducted transcriptional phenotyping of each sequenced tissue section based on the molecular characteristics of tumor-associated nerves and tumor immune infiltrate, utilizing gene signatures obtained from the literature. Nerves were evaluated according to the Cancer-Induced Nerve Injury (CINI) signature, which included the following genes: TAGAP, KCNJ8, COL1A1, PECAM1, TMEM119, ATF3, JUN, KLF6, NOCT, LMO7, CSF1, ENTPD1, UCHL1, PINK1, BHLHE41, ITGAM, CHL1, SNCA, SCPEP1, and VEGFA. The immune infiltrate was assessed using two signatures: Anti-tumoral Immunity (CD8A, PRF1, GZMB, IL12A, IFNG, IRF8, CD86, NOS2, TNF, and IL2) and Immunosuppression (IDO1, CTLA4, FOXP3, IL10, IL6, CD163, MSR1, MRC1, PDCD1, PDCD1LG2, and CD274). The strength of the correlation between the CINI and the immune signatures was evaluated.