Schwann cells as a target cell for the treatment of cancer pain.

Tumor erosion and metastasis can invade surrounding tissues, damage nerves, and sensitize the peripheral primary receptors, inducing pain, which can potentially worsen the suffering of patients with cancer. Reception and transmission of sensory signal receptors, abnormal activation of primary sensory neurons, and activation of glial cells are involved in cancer pain. Therefore, exploring promising therapeutic methods to suppress cancer pain is of great significance. Various studies have found that the use of functionally active cells is a potentially effective way to relieve pain. Schwann cells (SCs) act as small, biologically active pumps that secrete pain-relieving neuroactive substances. Moreover, SCs can regulate the progression of tumor cells, including proliferation and metastasis, through neuro-tumor crosstalk, which emphasizes the critical role of SCs in cancer and cancer pain. The mechanisms by which SCs repair injured nerves and exert analgesia include neuroprotection, neurotrophy, nerve regeneration, neuromodulation, immunomodulation, and enhancement of the nerve-injury microenvironment. These factors may ultimately restore the damaged or stimulated nerves and contribute to pain relief. Strategies for pain treatment using cell transplantation mainly focus on analgesia and nerve repair. Although these cells are in the initial stages of nerve repair and pain, they open new avenues for the treatment of cancer pain. Therefore, this paper discusses, for the first time, the possible mechanism of SCs and cancer pain, and new strategies and potential problems in cancer pain treatment.