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

Unlabelled: 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-2α. 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-1α and expanded ASCL1 cell populations, suggesting a lineage shift toward an immature chromaffin state. In contrast, long-term normoxic cultures activated hypoxia inducible factor 2α (HIF-2α) 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 Findings: PDOs can be successfully generated from PPGLs of various genetic backgrounds and reflect parental tumor propertiesPDO cultures grown in hypoxia retain main molecular features of parental tumors, have increased viability and a more immature developmental/biosynthetic profileLong term PDOs grown for 4 weeks in normoxia activate HIF2α, drift toward a hybrid sympathoblast-mesenchymal-like identity resembling relapsed/therapy resistant neuroblastomas, features that can be detected in primary tumorsA subset of PDOs respond to Abemaciclib, a drug class not previously used therapeutically in PPGLs.