Schwann cells drive tumor progression through neuro-tumor crosstalk

Different studies have confirmed the relationship between nerves and tumor cells. Nerve invasion leads to poor prognosis and increased mortality. Neural network in the tumor microenvironment provides the conditions for tumor diffusion and a strong relationship between nerve and tumor interaction, which is also supported by the cellular and molecular mechanisms in the process of nerve growth and nerve repair. Schwann cells (SCs) are the main glial cells of peripheral nerves. They play an important role in the repair of injured nerves, including neuroprotection, neurotrophic, nerve regeneration, nerve regulation, and immune regulation, and enhance the microenvironment of nerve injury. These cells form a complex tumor neural microenvironment during the progression of tumors, providing a good basis for tumor invasion and metastasis. SCs can promote tumor progression (refers to the deterioration of the growth, invasion, and metastasis of a malignant tumor, which is manifested by the increase in the volume of the primary tumor, the expansion of the scope of invasion, the appearance of new metastases, and the deterioration of biological behavior) through their phenotype (dedifferentiation). This change in cell phenotype is similar to SCs' response to peripheral nerve injury, revealing the unique biological characteristics of SCs. This article summarizes the biological characteristics of SCs and their functions in the repair of peripheral nerve injury. The possible mechanism of SCs-nerve-tumor crosstalk mode influencing tumor progression was emphatically discussed. Through the SCs level, changing the cell neural network environment to inhibit tumor progression has great prospects and application value.