Targeting VAMP5 suppresses PLK1-driven growth of gliomas with high NDRG4 expression

Background: SNAREs participate in tumor progression; however, existing studies on SNAREs remain fragmented. The discovery of suitable SNARE targets and delineation of their application limits are critical.

Methods: We performed integrative analyses on clinical data and RNA-seq data from TCGA to identify therapeutic targets in defined Cancer subtypes. These in silico findings were substantiated in patient-derived tumor sections, glioma cell lines, and xenografts. Gene/MicroRNA expression was modulated through lentiviral transduction. Omics methods, including RNA-seq, microRNA Sequencing, and data-independent acquisition proteomics, were used to localize/quantify downstream effectors, followed by characterization with antibody-based tests. MicroRNA sponge constructs were validated with qPCR.

Results: We evaluated VAMP5 as a glioma-selective therapeutic target and found two distinct response phenotypes following VAMP5 knockdown (KD). In the VAMP5-KD-sensitive subgroup, VAMP5 depletion universally suppressed PLK1, partly by reducing novel upregulatory MicroRNAs (miR-1301-3p and miR-12135), thereby inhibiting tumor cell proliferation. However, PLK1 expression remained unchanged in VAMP5-KD-insensitive tumors, making PLK1 a reliable pharmacodynamic marker. High NDRG4 expression predicted sensitivity to VAMP5 KD. NDRG4 overexpression induced in insensitive glioma lines converted them to a sensitive phenotype, enabling VAMP5-KD-induced PLK1 downregulation through coordinated modulation of additional MicroRNAs (classical tumor-suppressive miR-509-5p upregulation and novel upregulatory miR-1185-3p downregulation) and TNKS reduction (which was also shown to contribute to PLK1 downregulation in a subset of VAMP5-KD-sensitive lines). This NDRG4 OE plus VAMP5 KD cascade also diminished the immune checkpoint ligand VCAM1. We identified LGALS1 as a universal VAMP5-coexpressed immune modulator, suggesting that VAMP5 KD may further enhance antitumor immunity by downregulating LGALS1.

Conclusions: Our work provides a preliminary mechanistic framework for VAMP5 KD-mediated glioma suppression on proliferation or immune evasion and highlights several translational opportunities.