Pheochromocytomas and paragangliomas (PCPG) are rare neuroendocrine tumors associated with autonomic nerves. We used single nuclei-RNA-seq (snRNA-seq) for analysis of 30 PCPG representing 13 known driver genes, plus two normal adrenal medullas to dissect cell composition, refine PCPG subtypes and compare PCPG and normal tissue expression. Incorporating bulk-tissue and snRNA-seq data we identified seven PCPG gene-expression subtypes with genotype and cell type associations. The tumor microenvironment reflected HIF pathway activation and neovascularization by detection of abundant tip-like endothelial cells and pericytes concordant with VEGFA expression in neoplastic cells with mutations in VHL, genes encoding SDH subunits and MAML3-fusions. Macrophages were abundant in PCPG with distinct tumor-associated features. Schwann-cell-like cells were also enriched in some subtypes. The transcriptional profile of neoplastic PCPG cells resembled normal chromaffin cells but early chromaffin and neuroblast cell markers were expressed in some subtypes including GPR139, a putative therapeutic ... (Show More)

Pheochromocytomas and paragangliomas (PCPG) are rare neuroendocrine tumors associated with autonomic nerves. We used single nuclei-RNA-seq (snRNA-seq) for analysis of 30 PCPG representing 13 known driver genes, plus two normal adrenal medullas to dissect cell composition, refine PCPG subtypes and compare PCPG and normal tissue expression. Incorporating bulk-tissue and snRNA-seq data we identified seven PCPG gene-expression subtypes with genotype and cell type associations. The tumor microenvironment reflected HIF pathway activation and neovascularization by detection of abundant tip-like endothelial cells and pericytes concordant with VEGFA expression in neoplastic cells with mutations in VHL, genes encoding SDH subunits and MAML3-fusions. Macrophages were abundant in PCPG with distinct tumor-associated features. Schwann-cell-like cells were also enriched in some subtypes. The transcriptional profile of neoplastic PCPG cells resembled normal chromaffin cells but early chromaffin and neuroblast cell markers were expressed in some subtypes including GPR139, a putative therapeutic target for a subset of pseudohypoxic PCPG.

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