Abstract 1192: Selective sorting of tumor suppressive and oncogenic miRNAs into extracellular vesicles: Implications for cancer progression

Abstract Lung cancer remains the leading cause of cancer-related deaths worldwide, largely due to late diagnoses often coinciding with advanced, metastatic stages. Thus, a deeper understanding of the tumor microenvironment (TME) and the molecular mechanisms driving cancer progression and metastasis is critical. Among the many contributors to the TME, extracellular vesicles (EVs) are crucial in facilitating intercellular communication, enabling the transport of biomolecules such as lipids, RNAs, DNA, and proteins. Of the various biomolecules, microRNAs (miRNAs) have emerged as crucial regulators of both tumor cell behavior and the TME. Indeed, our own research has identified that EVs derived from non-small cell lung cancer (NSCLC) cells carry both tumor-suppressive and oncogenic miRNAs, which exert intrinsic effects on tumor cells and extrinsic effects on the TME. However, the mechanisms governing the selective loading of miRNAs into EVs and their role in modulating TME interactions remain unclear. This study aims to investigate EV-miRNA mediated intercellular communication, with a focus on both selective and non-selective enrichment of specific miRNAs within EVs and their implications in NSCLC. Through small RNA sequencing of EV-derived RNAs from NSCLC cells, we identified enrichment of oncogenic miRNAs, including miR-10b, miR-100, and miR-155, which collectively enhanced the invasive potential of bronchial epithelial cells. Functional antagonism of these miRNAs demonstrated their critical role in driving the invasive and migratory phenotypes induced by EVs. Concurrently, our research revealed a marked downregulation of multiple tumor-suppressive miRNAs in NSCLC cell lines, miRNAs that were selectively enriched within EVs. Sequence alignment analysis identified a conserved motif in approximately 60% of these selectively enriched EV-miRNAs. To determine the functional importance of this motif, we introduced point mutations within the motif that resulted in impaired loading of these miRNAs into EVs and their retention within cancer cells, suggesting that the motif is necessary for this active loading process. Ongoing research seeks to identify key players in the EV-miRNA export pathways and explore the differential loading and expression of miRNAs within EVs in cancer, thereby advancing our understanding of these mechanisms and potentially informing future therapeutic strategies for NSCLC. Citation Format: Samira Piltan, Humna Hasan, Ikjot Sohal, Aadya Pandey, Daniel Urdaneta, Nadia Lanman, Sagar Utturkar, Andrea Kasinski. Selective sorting of tumor suppressive and oncogenic miRNAs into extracellular vesicles: Implications for cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 1192.