Decoding NAMPT and TIGAR: A molecular blueprint for reprogramming tumor metabolism and immunity.

Abstract

e14537 Background: NAMPT and TIGAR, present in exosomes derived from pulsed dendritic cells (DEX), are key regulators of tumor metabolism and immune modulation. NAMPT catalyzes the biosynthesis of NAD+, crucial in regulating cellular processes such as DNA repair, cell survival, and apoptosis. TIGAR, on the other hand, modulates apoptosis and maintains the redox balance in cells, impacting tumor cell survival and resistance to therapy. The role of both NAMPT and TIGAR in the tumor microenvironment (TME) is critical for understanding how tumors manipulate metabolic and immune pathways to support their growth and resistance.This study examines how these proteins drive metabolic shifts and immune responses in complex tumors, emphasizing their potential in scalable, personalized therapies for aggressive, therapy-resistant cancers. Methods: DEX were generated using optimized pulses in semi-immortalized dendritic cells and processed under fresh, cryopreserved, and lyophilized conditions. NAMPT and TIGAR identification and quantification were performed by mass spectrometry (timsTOF Pro 2) with > 98% specific coverage. ZR-75-30 (breast) and HT-29 (colon) tumor cell lines were treated with 10, 50, and 100 µg/mL for 72 hours. Key cytokines (IL-12, IL-10, IFN-γ) were assessed by Cytometric Bead Array (CBA), and apoptosis was evaluated via Annexin V/PI staining and caspase-3 activation. Results: Quantification of NAMPT and TIGAR: o NAMPT: Fresh 18.9 ± 0.5 ng/mL vs Lyophilized 18.2 ± 0.4 ng/mL (p > 0.05). o TIGAR: Fresh 23.1 ± 0.7 ng/mL vs Lyophilized 22.4 ± 0.6 ng/mL (p > 0.05). Modulation of TME: o Increase in IL-12 (+57.8% ± 2.1, p < 0.001) and IFN-γ (+55.1% ± 1.8, p < 0.001). o Decrease in IL-10 (-42.4% ± 1.7, p < 0.01). Tumor Apoptosis: o ZR-75-30: 48.1% ± 2.9 apoptosis (lyophilized) vs 31.2% ± 2.1 (cryopreserved, p < 0.01). o HT-29: 46.5% ± 3.1 apoptosis (lyophilized) vs 29.7% ± 2.4 (cryopreserved, p < 0.01). Conclusions: NAMPT and TIGAR in DEX stand out as key modulators of the tumor microenvironment, promoting immune modulation and apoptosis in metabolically active and immunosuppressive tumors. Their high functional stability under lyophilization ensures the clinical viability of these exosomes in personalized therapies for pediatric, adolescent, and elderly patients. Lyophilized DEX, which preserve the activity of NAMPT and TIGAR, could serve as a transformative tool in clinical oncology, especially in precision medicine. By stabilizing these critical proteins, DEX-based therapies provide a promising route for overcoming resistance to conventional cancer treatments. This approach represents a significant advancement in precision oncology, establishing DEX as an essential and scalable therapeutic tool, making them accessible to underserved patient populations in both developed and resource-limited settings, thus broadening the impact of personalized treatments globally.