The embryonic trunk neural crest microenvironment regulates the plasticity and invasion of human neuroblastoma via TrkB signaling


Mistakes in trunk neural crest (NC) cell migration and differentiation may lead to neuroblastoma (NB) cancer. TrkB and its ligand, brain-derived neurotrophic factor (BDNF) are critical to normal NC development, but their over-expression in a majority of high-risk NBs is mechanistically unclear. In this study, we examined the functional relationship between TrkB expression and aggressive NB and asked whether signals within the embryonic microenvironment could regulate NB cell plasticity and invasion. To address this, we interrogated wildtype (LAN5, SHSY5Y, and NB1643) and TrkBmanipulated human NB cell behaviors and gene expression after in vivo transplantation into the chick embryonic trunk neural tube. Endogenous TrkB expression correlated with NB cell invasion, and gain- or loss-of-function promoted or deterred cell aggressiveness, respectively. Intriguingly, human NB cells downregulated 5 known NB tumor-initiation (ALDH1A, EPAS1, MTOR, NOTCH1, and VIM) and stem cell markers (including PAX6, RUNX1, SOX2/9, and NES) and showed enhanced expression of differentiation, neurogenesis, and development genes (including EYA1, RUNX1, RARB, and TH) after embryo exposure. Separate isolation and profiling of invasive human NB cells that remained in the chick embryo dorsal neural tube had enhanced expression of cell differentiation and cell adhesion genesand showed an improved disease outcome using a NB predictive computational algorithm. These data support TrkB as predictive of NB cell aggressiveness and demonstrate the potential of the embryonic trunk neural crest microenvironment to regulate NB invasion and plasticity, likely acting at the dorsal trunk neural tube.

BIORXIV, in progress