Dissecting the Reciprocal Influence between Cancer Cells and Fibroblasts in Pediatric Neuroblastoma

Neuroblastoma, the most prevalent extracranial tumor in pediatric patients, arises from the malignant transformation of neural crest progenitors within the peripheral sympathetic nervous system. The clinical and genetic heterogeneity of neuroblastoma poses significant challenges, particularly for high-risk tumors associated with poor overall survival. Recent studies have highlighted the existence of two distinct cell states, Adrenergic (ADR) and Mesenchymal (MES) neuroblastoma cells, whose interconversion is mediated by variations in epigenetic profiles and transcription factors. Notably, MES cells exhibit enhanced resistance to chemotherapy and migratory capability. Thus, novel approaches able to induce the switch from an MES to an ADR phenotype are under investigation. The tumor microenvironment plays a crucial role in tumor aggressiveness and chemoresistance by influencing tumor growth, angiogenesis, extracellular matrix remodeling, and metastatic dissemination. This study aimed to investigate the reciprocal influence between human MES neuroblastoma and fibroblast cells in different in vitro settings. In particular, this study focuses on the impact of MES or ADR neuroblastoma cells to induce the transformation of healthy fibroblasts into cancer-associated fibroblasts (CAF). In addition, the role of fibroblasts in impacting neuroblastoma cell migration has been evaluated. Our findings revealed that MES cells closely interact with fibroblasts to migrate in a three-dimensional in vitro co-culture system. Moreover, neuroblastoma cells showed the capability to modulate the transformation of fibroblasts into CAF. These insights provide a valuable understanding of the complex dynamics within the neuroblastoma microenvironment and highlight the importance of considering tumor niche heterogeneity in the development of effective therapeutic strategies.