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Substance P From Tumor Nerves Drives Cancer Growth Through the NK1 Receptor

evidence
The takeaway

Tumors across all types are densely innervated by sensory nerve fibers that release substance P, which stimulates cancer cell proliferation and migration through the NK1 receptor — a potentially universal anti-cancer target.

Universal tumor innervation

Regardless of cancer type, origin, or location, tumors are densely innervated by TRPV1+ sensory fibers that release growth-promoting substance P

What the researchers found

Research by Restaino and colleagues demonstrated that tumors across different types, origins, and anatomic locations are densely innervated predominantly by TRPV1+ sensory nerve fibers with likely functional connectivity contributing to increased electrical activity in the tumor bed. The neuropeptide substance P produced by these intratumoral fibers stimulates the neurokinin 1 receptor (NK1R) on tumor cells, driving proliferation and migration. This represents a potentially generalizable molecular pathway mediating cancer-nerve interaction across tumor types.

Why it matters

If substance P/NK1R signaling is a universal cancer growth mechanism, NK1R antagonists (some already approved for other uses like anti-nausea) could become broadly applicable cancer treatments. This reframes tumors not just as masses of abnormal cells but as organs with active nerve connections that drive their growth — opening an entirely new therapeutic front.

How the study worked

This is a commentary/perspective article discussing findings from the Restaino et al. study on nerve-tumor interactions. The underlying research used anatomical and functional characterization of tumor innervation across multiple cancer types, with molecular dissection of the substance P/NK1R signaling axis.

What this study cannot tell us

This is a commentary article, not original research, so it discusses findings from a single referenced study. While the concept of universal tumor innervation is compelling, the degree to which substance P/NK1R signaling drives growth may vary across cancer types and stages. Clinical validation of NK1R antagonists as anti-cancer agents is still needed.

How to read the evidence

This is a commentary article discussing a single preclinical study. While the concept is scientifically significant and well-supported by the referenced data, it represents an early-stage hypothesis about a universal cancer mechanism that requires broad clinical validation.

When this study was published

Published in 2023, this commentary reflects the rapidly growing field of cancer neuroscience and neuropeptide signaling in the tumor microenvironment.

The bigger picture

The emerging field of cancer neuroscience is revealing that nerves are not passive bystanders in tumors — they actively promote cancer progression. This adds neuropeptides like substance P to the list of druggable targets in oncology, alongside immune checkpoints, kinases, and hormones. NK1R antagonists like aprepitant (already used for chemotherapy-induced nausea) could potentially be repurposed for anti-cancer effects.

Questions still open

  • Could existing NK1R antagonists like aprepitant be repurposed as anti-cancer drugs, alone or in combination with existing treatments?
  • Do all cancer types depend equally on substance P signaling, or are some more nerve-dependent than others?
  • Could blocking tumor innervation at the nerve level (denervation) provide additional anti-cancer benefits beyond NK1R blockade?

Common questions

How do nerves help cancer grow?
Tumors attract nerve fibers that grow into and around them. These nerves release chemical messengers, including the peptide substance P, that act directly on cancer cells to make them grow faster and spread more. This nerve-cancer communication loop means the nervous system actively supports tumor development.
Are there already drugs that block substance P?
Yes. NK1 receptor antagonists like aprepitant are FDA-approved for preventing chemotherapy-induced nausea. If research confirms that blocking substance P signaling inhibits tumor growth, these existing drugs could potentially be repurposed for anti-cancer use relatively quickly.

Read the original research

Targeting the Nerve-Cancer Circuit.

Cancer research, 83(15), 2445-2447

Citation

Ye, Yi; Xie, Tongxin; Amit, Moran. (2023). Targeting the Nerve-Cancer Circuit.. Cancer research, 83(15), 2445-2447. https://doi.org/10.1158/0008-5472.CAN-23-1754