Gultekin, Sakir H.

Abstract Gliomas are highly malignant brain tumors with poor prognosis and short survival. Nicotinamide adenine dinucleotide (NAD+) plays a critical role in cancer progression, yet anti-cancer therapies targeting NAD+ synthesis have had limited clinical success due to an incomplete understanding of its mechanisms. Here, we demonstrate the essential role of the NAD+ synthase nicotinamide mononucleotide adenylyltransferase (NMNAT) in glioma progression and its novel contribution to nuclear atypia. Analysis of the patient glioma transcriptomics dataset (GAPIA) indicated a strong correlation between high NMNAT transcription levels and poorer disease-free survival in low grade glioma (LGG) and glioblastoma multiforme (GBM). Utilizing quantitative statistical analysis to assess the size and circularity of about 3 million cells in glioma tissue samples from 19 patients, we identified the significant association between NMNAT1 protein level and increased nuclear atypia in different types of gliomas. Mechanistic studies in human glioma cells and a Drosophila glial neoplasia model revealed that NMNAT enhances glioma growth by promoting NAD+-dependent post-translational modifications poly(ADP-ribosyl)ation (PARylation) and deacetylation of p53, thereby attenuating the pro-apoptotic activity of p53. Additionally, NMNAT1 disrupts nuclear lamina integrity by altering lamin A/C distribution, further contributing to nuclear atypia and glioma progression. These findings uncover a novel tumorigenic mechanism involving NMNAT's regulation of nuclear architecture and NAD+-mediated metabolic signaling pathways, highlighting its roles in glioma growth and nuclear atypia. This study underscores NMNAT as a potential therapeutic target in glioma treatment. Citation Format: Jiaqi Liu, Xianzun Tao, Yi Zhu, Xiang Gao, Tijana Canic, Kai Ruan, Zoraida Diaz-Perez, Sakir Humayun Gultekin, Priyamvada Rai, Qunfeng Dong, Grace Zhai. NMNAT-mediated NAD+ metabolism promotes glioma growth by modulating p53 post-translational modifications and nuclear atypia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_2):Abstract nr LB060.

Abstract Background: Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma of childhood with a propensity to metastasize. Current treatment for patients with RMS includes conventional systemic chemotherapy, radiation therapy and surgical resection; nevertheless, little to no improvement in long term survival has been achieved in decades – underlining the need for target discovery and new therapeutic approaches to targeting tumor cells or the tumor microenvironment.Methods:To evaluate cross-species sarcoma extracellular matrix production, we have used murine models which feature knowledge of the myogenic cell-of-origin. With focus on the RMS/undifferentiated pleomorphic sarcoma (UPS) continuum, we have constructed tissue microarrays of 48 murine and 4 human sarcomas to analyze expression of 7 different collagens, fibrillins and collagen-modifying proteins, with cross-correlation to RNA deep sequencing.Results:We have uncovered that RMS produces increased expression of type XVIII collagen alpha 1 (COL18A1), which is clinically associated with decreased long-term survival. We have also identified significantly increased RNA expression of COL4A1, FBN2, PLOD1 and PLOD2 in human RMS relative to normal skeletal muscle.Conclusion:These results complement recent studies investigating whether soft tissue sarcomas utilize collagens, fibrillins and collagen-modifying enzymes to alter the structural integrity of surrounding host extracellular matrix/collagen quaternary structure resulting in improved ability to improve the ability to invade regionally and metastasize, for which therapeutic targeting is possible.