The functioning of the nervous system is based on highly sophisticated neural networks that are formed during fetal life and childhood. During development, neurons emit long cables, called axons, to reach their target cells and establish synaptic contacts. This process is controlled by groups of specialized cells that express guidance signals and direct axons along specific trajectories. The nerve projections thus established are maintained throughout adult life. Far from being static, they retain a degree of plasticity that allows them to reshape themselves according to our experiences or in response to diseases such as cancer. Indeed, malignant tumors are able to stimulate the regrowth of mature axons and thus promote their own innervation. The importance of this phenomenon on the evolution of the disease is only beginning to be understood: the nervous system has a protective or, on the contrary, accelerating effect on tumor development, which depends on both the type of cancer and the biochemical properties of the infiltrated axons. These results raise fundamental questions that we seek to answer:

How do axonal projections remodel as a tumor develops?

How does the combination of chemical and mechanical signals generated by the tumor control axonal growth and plasticity?
How do neurons interact with cells in the tumor microenvironment and contribute to disease progression?