DLL3 Is a Prognostic and Potentially Predictive Biomarker for Immunotherapy Linked to PD/PD-L Axis and NOTCH1 in Pancreatic Cancer

Exploring the expression of DLL3 in gastroenteropancreatic neuroendocrine neoplasms and its potential diagnostic value

Delta-like protein (DLL3) is a novel therapeutic target. DLL3 expression in gastroenteropancreatic neuroendocrine tumors (GEP-NECs) is poorly understood, complicating the distinction between well-differentiated neuroendocrine tumors G3 (NET G3) and poorly differentiated NEC. DLL3 immunohistochemistry (IHC) was performed on 248 primary GEP-NECs, correlating with clinicopathological parameters, NE markers, PD-L1, Ki67 index, and prognosis. Achaete-scute complex-like 1 (ASCL1) IHC was performed on some GEP-NECs. DLL3 IHC was conducted on 36 GEP-NETs, 29 gastric adenocarcinomas (GACs), and metastatic tumors (9 lymph node metastases and 19 distant metastases). DLL3 expression rates were 54.8% in GEP-NECs at the primary site, associated with small cell neuroendocrine carcinoma (SCNEC) (p < 0.001), chemotherapy before baseline (p = 0.015), and at least two NE markers (p = 0.048). DLL3 expression in metastatic GEP-NECs was similar to that of primary tumors. Expression rates in NET G1, NET G2, NET G3, and GACs were 0%, 0%, 15.8%, and 0%, respectively, highlighting DLL3 as a powerful tool for identifying poorly differentiated NEC. DLL3 expression was related to ASCL1 in GEP-NECs, especially in SCNEC. It was not correlated with progression-free survival (PFS) or overall survival(OS), regardless of cutoff value (1%, 50%, 75%). In conclusion, DLL3 targeted therapy may offer potential for the treatment of poorly differentiated NEC of the digestive system, although further studies are needed to validate its efficacy.

DLL3 as a potential diagnostic and therapeutic target in neuroendocrine neoplasms: A narrative review

Neuroendocrine neoplasms (NENs) represent a diagnostic and therapeutic challenge, due to their heterogeneity and limited treatment options. Conventional imaging techniques and therapeutic strategies may become unreliable during follow-up, due to the tendency of these neoplasms to dedifferentiate over time. Therefore, novel diagnostic and therapeutic options are required for the management of NEN patients. Delta-like ligand 3 (DLL3), an inhibitory ligand of Notch receptor, has emerged as a potential target for novel diagnostic and therapeutic strategies in NENs, since overexpression of DLL3 has been associated with tumor progression, poor prognosis and dedifferentiation in several NENs. This narrative review examines the current evidence about DLL3, its structure, function and association with tumorigenesis in NENs. Ongoing studies exploring the role of DLL3 as an emerging diagnostic marker are reviewed. Promising therapeutic options, such as antibody-conjugated drugs, CAR-T cells and radioimmunoconjugates, are also discussed.

Novel insights into Notch signaling in tumor immunity: potential targets for cancer immunotherapy

Notch signaling pathway is a highly conserved system of cell-to-cell communication that participates in various biological processes, such as stem cell maintenance, cell fate decision, cell proliferation and death during homeostasis and development. Dysregulation of Notch signaling has been associated with many aspects of cancer biology, such as maintenance of cancer stem-like cells (CSCs), cancer cell metabolism, angiogenesis and tumor immunity. Particularly, Notch signaling can regulate antitumor or pro-tumor immune cells within the tumor microenvironment (TME). Currently, Notch signaling has drawn significant attention in the therapeutic development of cancer treatment. In this review, we focus on the role of Notch signaling pathway in remodeling tumor immune microenvironment. We describe the impact of Notch signaling on the efficacy of cancer immunotherapies. Furthermore, we summarize the results of relevant preclinical and clinical trials of Notch-targeted therapeutics and discuss the challenges in their clinical application in cancer therapy. An improved understanding of the involvement of Notch signaling in tumor immunity will open the door to new options in cancer immunotherapy treatment.