Single-cell transcriptomics of human embryos identifies multiple sympathoblast lineages with potential implications for neuroblastoma origin

Abstract

Characterization of the progression of cellular states during human embryogenesis can provide insights into the origin of pediatric diseases. We examined the transcriptional states of neural crest- and mesoderm-derived lineages differentiating into adrenal glands, kidneys, endothelium, and hematopoietic tissue between post-conception weeks 6 and 14 of human development. Our results reveal transitions connecting intermediate mesoderm and progenitors of organ primordia, the hematopoietic system, and endothelial subtypes. Unexpectedly, by using a combination of single cell transcriptomics and lineage tracing, we found that intra-adrenal sympathoblasts at that stage are directly derived from the nerve-associated Schwann cell precursors similarly to local chromaffin cells, whereas the majority of extra-adrenal sympathoblasts arise from the migratory neural crest. In humans, this process persists during several weeks of development within the large intra-adrenal ganglia-like structures, which may also serve as reservoirs of originating cells in neuroblastoma.

MEIS2 Is an Adrenergic Core Regulatory Transcription Factor Involved in Early Initiation of TH-MYCN-Driven Neuroblastoma Formation

“…To this end, we compiled a DREAM/FOXM1 signature [ 72 ] and could show significant upregulation during TH-MYCN-driven neuroblastoma formation ( Figure 6 B, panel 2). We verified the expression of HMGB2 in single-cell RNA-seq data of the developing sympathoadrenal lineage, showing prominent expression in the proliferating sympathoblasts [ 49 ]. This was in line with the strongest HMGB2 expression in the cycling neuroblast cell population of the adrenal medulla [ 50 ] ( Figure 6 B, panel 3).…”

“…Recent single-cell transcriptome analysis of the developing sympatho-adrenal lineage evidenced [ 49 ] strong enriched MEIS2 expression in the population of sympathoblast cells that resemble the neuroblastoma cancer cell phenotype compared to chromaffin and Schwann cell precursor cells ( Figure 3 F, left). We also verified the MEIS2 expression pattern in the recent single-cell transcriptome data of the adrenal medulla by Jansky et al ( Figure 3 F, right) [ 50 ], showing prominent expression in the neuroblast population from which neuroblastoma cells are assumed to originate.…”

“…In total, 24 overlapping genes could be retrieved, with high expression of 15 of those significantly correlating to poor overall patient survival in human primary neuroblastoma ( Figure 5 A, left, GSE45547, n = 649). Single-cell RNA-seq data of the sympathoadrenal lineage and adrenal medulla respectively indicate that CDCA8 displays nearly exclusive strong expression in the proliferating sympathoblasts [ 49 ] and cycling neuroblast population [ 50 ] ( Figure 5 B).…”

“…In addition to ALK and ASCL1 that were previously reported in the context of neuroblastoma, a novel interesting candidate gene “Claspin” ( Clspn ) was identified, for which recently a critical role was described in protection of cancer cells from replication stress and which has been reported as a key gene in normal developmental controlled gene amplification in Drosophila [ 67 ]. Single-cell RNA-seq data of the sympathoadrenal lineage and adrenal medulla respectively indicate that CLSPN displays nearly exclusive strong expression in the proliferating sympathoblasts [ 49 ] and cycling neuroblast population [ 50 ] ( Figure 5 D, bottom) We also evaluated the overlap of the set of significantly upregulated genes in the course of murine TH-MYCN-driven neuroblastoma tumor development with the neuroblastoma specific dependencies as defined by the recent pediatric cancer dependency map from Dharia et al [ 68 ]. When again only considering those genes that also significantly correlate with a poor overall neuroblastoma patient survival, we identified 11 additional candidate dependency genes that were significantly differentially expressed (absolute log 2 fold change threshold of 1 and adjusted p < 0.01) between TH-MYCN +/+ and wild-type mice exclusively at Week 6 compared to Week 1 ( AGBL5 , ATAD5 , CHEK1 , HDX , NEDD1 , PABPC1 , PHF19 , POLD1 , PYCR1 , SMC2 and WNT5B ) that were not identified as “MYCN-amplified/neuroblastoma” specific dependencies by the Avana CRISPR screen from the Depmap initiative.…”

Bone Marrow Environment in Metastatic Neuroblastoma

“…Presently, conflicting results have been published [ 57 , 58 , 59 , 60 , 61 ] regarding their developmental origin, but definitive results will certainly come in the next few years. As for the plasticity, it is interesting to note that already in 2007, Martinez et al described the presence of GD2+/CD45− cells with mesenchymal phenotype in the BM of children with NB [ 62 ].…”