Disrupted WWOX-MYC interplay impairs neurogenesis in human brain organoids.

Abstract

WOREE and SCAR12 syndromes are rare neurodevelopmental disorders caused by WWOX mutations, severely impairing brain development. The pleiotropic nature of WWOX complicates identifying specific mechanisms, thus, the specific molecular pathways affected by WWOX deficiency and how they contribute to disease pathogenesis remain largely unknown. Using neural organoids derived from a broad iPSC cohort, including wildtype iPSCs, CRISPR-edited isogenic WWOX-knockout lines, and patient-derived lines, we applied molecular profiling and single-cell transcriptomics to map the early neurodevelopmental pathways disrupted upon loss of WWOX. We identified radial glial cells (RGs) as preferentially affected, with disrupted cell cycle dynamics leading to an accumulation of cells in the G2/M and S phases, overexpression of the proto-oncogene MYC, and concomitant reduction in neuronal generation. Patient-derived organoids exhibited milder phenotypes compared to knockout organoids, showing functional neuronal impairments like hyperexcitability and delayed differentiation rather than RG dysfunction. Remarkably, gene therapy restored neuronal function, normalizing hyperexcitability and promoting maturation, without disturbing RG populations. We propose a model in which WWOX mutations impair neurogenesis via RG through cell-type specific dysregulation of the MYC and Wnt signaling pathways. These insights highlight potential therapeutic strategies for WWOX-related disorders and open avenues for interventions targeting these key molecular pathways.