Molecular characterization of perineural invasion-competent cancer cells using a novel in vitro model

Invasion of cancer cells into peripheral nerves, known as perineural invasion (PNI), is an established risk factor for cancer recurrence and metastasis. However, there are no approaches available to specifically target PNI-competent cancer cells for diagnostic and therapeutic purposes. The lack of ideal preclinical models simulating natural PNI challenges the true characterization of PNI cells and understanding of the cellular events underlying PNI. In this work, we developed an in vitro model recapitulating the biological events associated with natural PNI. The novel in vitro model included intact nerve preparations in 3D culture format to facilitate natural PNI. Using the novel model, we found that autonomic neurosignaling promotes PNI demonstrating the utility of this model in exploring the fundamental biology of PNI. Using this model, we also demonstrated that PNI cells have survival advantages against cancer chemotherapy further demonstrating the utility of this model in screening potential anti-PNI therapies. We also characterized the molecular profile of PNI-competent breast cancer cells purified from the in vitro model. Follow-up analysis showed that CPLANE1 and hemopexin are potential markers of PNI cells for future theranostics purposes. Overall, this work presents a new in vitro model of PNI, which can be used to study the fundamentals of PNI and screen potential anti-PNI therapies.