Neurite outgrowth involves reciprocal signaling interactions between tumor cells and nerves where invading tumor cells have acquired the ability to respond to pro-invasive signals within the nerve environment. Neurite outgrowth could serve as a mechanism leading to invasion of cancer cells into the nerve sheath and subsequent metastasis. Snail transcription factor can promote migration and invasion of prostate cancer cells. We hypothesized that prostate cancer cell interaction with nerve cells will be mediated by Snail expression within prostate cancer cells. For this study we utilized various prostate cancer cell lines: C4-2 non-silencing (NS, control); C4-2 Snail shRNA, (stable Snail knockdown); LNCaP Neo (empty vector control) and LNCaP Snail (stably over-expressing Snail). Cancer cell adhesion and migration towards nerve cells (snF96.2 or NS20Y) was examined by co-culture assays. Conditioned media (CM) collected from C4-2 cells was cultured with nerve cells (PC-12 or NS20Y) for 48 h followed by qualitative or quantitative neurite outgrowth assay. Our results showed that cancer cells expressing high levels of Snail (LNCaP Snail/C4-2 NS) displayed significantly higher migration adherence to nerve cells, compared to cells with lower levels of Snail (LNCaP Neo/C4-2 Snail shRNA). Additionally, LNCaP Snail or C4-2 NS (Snail-high) CM led to a higher neurite outgrowth compared to the LNCaP Neo or C4-2 Snail shRNA (Snail-low). In conclusion, Snail promotes migration and adhesion to nerve cells, as well as neurite outgrowth via secretion of soluble factors. Therefore, targeting cancer cell interaction with nerves may contribute to halting prostate cancer progression/metastasis.

神经突生长涉及肿瘤细胞和神经之间的相互信号相互作用，其中入侵的肿瘤细胞已经获得了对神经环境内的促侵袭信号做出反应的能力。神经突生长可以作为导致癌细胞侵入神经鞘和随后转移的机制。蜗牛转录因子可以促进前列腺癌细胞的迁移和侵袭。我们假设前列腺癌细胞与神经细胞的相互作用将由前列腺癌细胞内的 Snail 表达介导。对于这项研究，我们使用了各种前列腺癌细胞系：C4-2 非沉默（NS，对照）；C4-2 Snail shRNA，（稳定的 Snail 敲低）；LNCaP Neo（空载体对照）和 LNCaP Snail（稳定过表达的 Snail）。癌细胞粘附和向神经细胞迁移（snF96. 2 或 NS20Y) 通过共培养测定进行检查。从 C4-2 细胞收集的条件培养基 (CM) 与神经细胞 (PC-12 或 NS20Y) 一起培养 48 小时, 然后进行定性或定量神经突生长测定。我们的结果表明，与具有较低水平 Snail 的细胞（LNCaP Neo/C4-2 Snail shRNA）相比，表达高水平 Snail（LNCaP Snail/C4-2 NS）的癌细胞对神经细胞的迁移粘附显着更高。此外，与 LNCaP Neo 或 C4-2 Snail shRNA（Snail-low）相比，LNCaP Snail 或 C4-2 NS（Snail-high）CM 导致更高的神经突生长。总之，Snail 通过分泌可溶性因子促进迁移和与神经细胞的粘附，以及神经突的生长。因此，靶向癌细胞与神经的相互作用可能有助于阻止前列腺癌的进展/转移。