The SHH/GLI target Netrin-1 supports self-renewal in medulloblastoma tumor cells

Deregulation of the Sonic Hedgehog (SHH)/GLI signaling pathway has been strongly implicated in carcinogenesis, particularly in brain and skin tumors, through mutations affecting various pathway components. Given its central role in tumor development, the SHH/GLI axis has emerged as a key target for therapeutic intervention, underscoring the need to identify GLI-specific targets in cancer cells. Netrin-1, a multifunctional signaling molecule with pro-oncogenic properties, is overexpressed in diverse tumor types. While its tumor-promoting functions are well documented, the regulatory mechanisms governing its expression remain poorly understood. Here, we provide through gene expression profiling and in vitro and ex vivo analyses evidence demonstrating that Netrin-1 (NTN1) is a direct transcriptional target of canonical SHH signaling. We further show that in conditions of SHH pathway hyperactivation-such as in SHH-driven medulloblastoma (MB) NTN1 is significantly upregulated. This overexpression promotes the self-renewal of MB stem-like cells through the modulation of ERK signaling, thereby contributing to enhanced cancer stemness. Our findings identify NTN1 as a novel downstream effector of the SHH/GLI pathway and demonstrate that quantifying NTN1 levels can refine molecular classification of SHH-subtype medulloblastomas-distinguishing tumors with high SHH pathway activation and enhanced stem-like properties, with potential implications for prognosis and targeted therapy selection.