This raises many many questions, like…how do newly born neural cells know how to get all the way from the brain to a tumor so far away? How do these cells make it past the blood brain barrier (BBB), and even if they do make it this far….how do we know that the cells that make it to the prostate are the same ones that left the brain? There are, after all, neurons in the peripheral nervous system (PNS) that could be infiltrating the tumor to cause these effects. The idea that newly born neurons can leave the nervous system is pretty wild on its own…but the claim that they not only leave, but migrate all the way to a distant tumor where they promote its growth is amazing….if true! Below, I’ll go through the primary figures in this paper one by one and explain what the authors are showing. If I feel like something is missing, or there could have been additional work done, I will say so. So far…it feels like this paper has not gotten the attention it deserves…probably because neuroscientists rarely talk to cancer biologists!

The authors started by looking at prostate tumor samples to see if they indeed contain neural progenitor cells. To label these types of cells specifically, they applied antibodies against doublecortin (DCX) which were tagged with a green fluorescent molecule. This way, all the DCX-expressing cells (i.e., neural progenitor cells) appeared green under a microscope. As one marker is not enough to convince the editors at Nature, they showed that these cells also express other markers of immature neurons (PSA-NCAM, internexin), but not markers of mature neurons (neurofilament-heavy (NF-H)) or epithelial cells (Pancytokeratin (PanCK)).