Interplay between intrinsic reprogramming potential and microenvironment controls neuroblastoma cell plasticity and identity

Abstract

Two cell identities, noradrenergic and mesenchymal, have been characterized in neuroblastoma cell lines according to their epigenetic landscapes relying on specific circuitries of transcription factors. Yet, their relationship and relative contribution in patient tumors remain poorly defined. Here, we demonstrate that the knock-out of GATA3, but not of PHOX2A or PHOX2B, in noradrenergic cells induces a mesenchymal phenotype. Our results document spontaneous plasticity in several models between both identities and show that plasticity relies on epigenetic reprogramming. We demonstrate that an in vivo microenvironment provides a powerful pressure towards a noradrenergic identity for these models. Consistently, tumor cells with a mesenchymal identity are not detected in a series of PDX models. Further study of the intra-tumor noradrenergic heterogeneity reveals two distinct cell populations exhibiting features of chromaffin-like or sympathoblast-like cells. This work emphasizes that both external cues of the environment and intrinsic factors control plasticity and cell identity in neuroblastoma.

Clinically-relevant treatment of PDX models reveals patterns of neuroblastoma chemoresistance

“…Our analyses revealed substantial genetic diversity, as well as high intra-and inter-tumor heterogeneity, at both the DNA and transcriptional levels. NB PDXs in mice with upfront progression during chemotherapy and relapsed NB PDXs after chemotherapy showed an immature transcriptional phenotype that resembles the previously described MES-like cell state (10,12,(15)(16)(17)19). In contrast, NB tumors from mice that were cured after COJEC and surgical resection showed, at the time of surgical resection, features of nervous system development that resemble the ADR cell state (10,12,(15)(16)(17)19).…”

“…Several studies have demonstrated the existence of at least two transcriptional cell states in NB: an immature MES-like cell state and an ADR differentiated cell state (10)(11)(12)(13)(15)(16)(17)(18)(19). There is consensus across studies for the ADR cell state, but inconsistencies exist in the definition of the immature MES-like state, with some data even questioning the existence of this cell state beyond cell culture (12,45). The discordances observed between studies could be due to differences in methodology, including technical and bioinformatic methods, or sample material, such as cell lines, mouse models, PDXs, or patients, or the use of treatment naïve vs. treated tumors.…”

“…NB is mainly driven by large chromosomal aberrations and is characterized by a low number of somatic driver mutations, even after relapse, and high interand intratumor heterogeneity (8,9). Transcriptional and epigenetic analyses revealed that NB can exhibit at least two phenotypic cellular states, which are commonly referred to as ADR and MES (10)(11)(12)(13)(14)(15)(16)(17)(18)(19). Cells in the ADR state are lineage-committed sympathetic nor-adrenergic cells.…”

“…Cells in the MES state are immature neural crest cell-like or undifferentiated mesenchymal-like cells. Both states have been detected in established conventional cell lines (10)(11)(12)(13)(14) and in patient samples (13)(14)(15)(16)(17)(18)(19). In cell culture studies, MES cells are implicated in NB treatment resistance (10,12,20,21).…”

Loss of p16INK4a in neuroblastoma cells induces shift to an immature state with mesenchymal characteristics and increases sensitivity to EGFR inhibitors

“…Future experiments will have to explore different drug combinaMons and confirm our results in other mouse models. The SY5Y cell line is interesMng due to its SKNSH-derived clonal origin and its ability to transdifferenMate between a noradrenergic and a mesenchymal state 55 . Future experiments will have to elucidate the potenMal correlaMon between p16/CDKN2A and a phenotypic switch and invesMgate whether a mesenchymal transiMon occurs upon p16 knockout in other neuroblastoma models.…”