DLL3 serves as a pivotal hub bridging malignant progression and immunosuppression in NECC with therapeutic implications validated via organoid-TILs co-culture system

Neuroendocrine carcinoma of the cervix (NECC) represents a highly aggressive cervical cancer subtype with poorly characterized tumor immune microenvironment (TIME) and unclear oncogenic mechanisms. Herein, 1) Through scRNA-seq analysis, we identified neuronal progenitor cells (NPCs) exhibiting high expression of NECC markers (SYN/INSM1) as putative malignant cells, and delineated three distinct NPC states along their developmental trajectory. Notably, we observed extensive infiltration of both naïve and exhausted T cells, collaboratively shaping an immunosuppressive TIME. 2) Cellular communication analysis discovered DLL3's interaction with NOTCH2 on NPCs and NOTCH1/2 on tumor-infiltrating lymphocytes (TILs), with spatial relationships validated by multicolor immunohistochemistry staining. Functional experiments demonstrated that DLL3 promoted tumor cell proliferation and invasion whereas co-culture assays revealed that DLL3 contributed to T cell exhaustion and impaired T cell activation, collectively proving DLL3 as a central molecular hub coordinating both malignant progression and immunosuppression. Moreover, we verified heightened and specific DLL3 expression in NECC tissues through immunohistochemistry staining, underscoring DLL3 as a promising therapeutic target for NECC. 3) Significantly, we not only innovatively established NECC-derived organoids replicating cellular morphology, neuroendocrine differentiation features, and genetic characteristics of parental tumors, but also co-cultured organoids with tumor-infiltrating lymphocytes to assess the therapeutic efficacy of AMG757 targeting DLL3. Remarkably, the combination of AMG757 targeting DLL3 with chemotherapy (etoposide+cisplatin) induced substantial T cell aggregation and activation and heightened immunogenic cell death, offering novel insights into NECC treatment. Overall, the study provides comprehensive insights into NECC TIME and tailored therapeutic approaches beyond traditional therapy for NECC.