Tischler, A. | bioRxiv Science

bioRxiv2026

Sympathoadrenal Lineage Plasticity Drives Intratumoral Heterogeneity in Paraganglioma, Neuroblastoma and Composite Tumors Following KIF1Bb-NF1 Loss

Neuroblastoma (NB) and paraganglioma (PPGL) arise from the sympathoadrenal lineage, yet their developmental relationship and heterogeneity remain unclear. Single-cell and spatial transcriptomics revealed shared, spatially organized developmental states, including populations characteristic of the other tumor type, chromaffin-like cells in NB and neuroblast-like cells in PPGL and hybrids co-expressing adjacent states. Deconvolution of an independent PPGL cohort associated metastatic disease most strongly with chromaffin hybrid states, alongside connecting progenitor-like, cycling neuroblast, and early chromaffin identities, whereas non-metastatic tumors were enriched for differentiated late chromaffin identities. In mice, combined loss of the candidate 1p36 tumor suppressor KIF1B{beta} and NF1 recapitulates these developmental architectures by prolonging developmental plasticity, reactivating embryonic neurogenic programs, and driving chromaffin-to-neuroblast transitions generating pheochromocytoma, neuroblastoma and composite tumors. Mouse tumors contained discrete spatial domains of developmental and neoplastic states that mirrored those in human PPGL. Together, our findings establish chromaffin-neuroblast plasticity as a mechanism of sympathoadrenal tumor heterogeneity and identify hybrid developmental states as a potential indicator of plasticity associated with metastatic PPGL.

cancer biology↗

bioRxiv2025

Patient-derived organoids reveal hypoxia-driven plasticity and therapeutic vulnerabilities in pheochromocytomas and paragangliomas

Pheochromocytomas and paragangliomas (PPGLs) are rare chromaffin cell-derived neuroendocrine tumors of sympathetic (catecholamine-producing) or parasympathetic (nonsecretory) origin, frequently driven by dysregulation of hypoxia-inducible factor (HIF) signaling, particularly HIF-2. Although often benign, PPGLs can metastasize unpredictably, with limited therapeutic options once disseminated. Progress has been hindered by the lack of robust preclinical models, especially those that capture their molecular complexity and microenvironmental influences. To address this gap, we established patient-derived tumor organoids (PDOs) from 35 PPGLs, encompassing a broad spectrum of clinical and molecular phenotypes. The organoids retained key immunohistochemical, genomic, transcriptomic, and catecholamine-secretory features of their parental tumors. PPGL organoids cultured under hypoxic conditions generally exhibited enhanced viability, supporting hypoxia as a driver of cell survival. Hypoxia activated HIF-1 and expanded ASCL1+ cell populations, suggesting a lineage shift toward an immature chromaffin state. In contrast, long-term normoxic cultures activated hypoxia inducible factor 2 (HIF-2) and acquired a hybrid sympathoblast-mesenchymal identity in subpopulations with upregulation of extracellular matrix and cell cycle markers, independent of genotype. These features resemble high-risk neuroblastoma subtypes and establish a molecular parallel suggestive of shared lineage plasticity and pathogenic programs, detectable in primary PPGLs. Drug screening across a library of up to 51 drugs and combinations revealed both shared and unique vulnerabilities, with response rates to approved therapies matching clinical observations. The CDK4/6 inhibitor abemaciclib, previously unexplored in PPGLs, elicited the strongest activity. Abemaciclib-responsive PDOs and their matched tumors, including a metastatic sample, exhibited epithelial mesenchyme transition enrichment, nominating potential biomarkers for patient stratification. Our results establish PDOs as a novel platform for modeling neuroendocrine tumor biology, reveal microenvironment-driven plasticity in PPGLs, with potential translational relevance, and identify actionable vulnerabilities in a disease with few effective systemic therapies. Main findingsO_LIPDOs can be successfully generated from PPGLs of various genetic backgrounds and reflect parental tumor properties C_LIO_LIPDO cultures grown in hypoxia retain main molecular features of parental tumors, have increased viability and a more immature developmental/biosynthetic profile C_LIO_LILong term PDOs grown for 4 weeks in normoxia activate HIF2, drift toward a hybrid sympathoblast-mesenchymal-like identity resembling relapsed/therapy resistant neuroblastomas, features that can be detected in primary tumors C_LIO_LIA subset of PDOs respond to Abemaciclib, a drug class not previously used therapeutically in PPGLs C_LI

cancer biology↗