Abstract 5373: ALDOA reprograms stemness and mitochondrial function in lung cancer by facilitating lactylation of m6A regulators

Abstract Lactic acid-derived lactylation has recently emerged as a novel post-translational modification (PTM). This modification has been shown to regulate the N6-methyladenosine (m6A) modification mechanism, thereby influencing RNA function. In lung cancer progression, dysfunctional aldolase (ALDOA) forms a positive feedback loop with HIF-1α, promoting lactate accumulation in the tumor and its microenvironment. We observe increased lactate production, hypoxia, acidification of the tumor microenvironment and increased lactylation levels of m6A regulators. In particular, METTL16, a key m6A transcription factor, was found to be modified by lactate. We also developed a methylated m6A RNA immunoprecipitation (MeRIP) platform and identified ATPIF1, an inhibitor of mitochondrial F0F1-ATP synthase, as a direct target of lactylation. In our overexpression model, ATPIF1 was degraded following m6A modification, which activated ATP biosynthesis. In a METTL16 knockout model, ATPIF1 expression was restored, leading to impaired ATP production and mitochondrial membrane potential. In addition, cancer spheroid formation and associated markers were reduced. Our in vivo model mirrored these findings, showing lactate-induced acidification and up-regulation of molecules involved in cancer stemness and mitochondrial function within the tumor region. Using multiplex staining, we detected reduced ATPIF1 expression alongside ALDOA overexpression, increased mitochondrial membrane potential and increased expression of OXPHOS-related molecules. In conclusion, we propose that ALDOA accelerates glycolysis in lung cancer progression and increases the global lactylation status of m6A regulators. These findings highlight lactylation as a critical aspect of metabolic reprogramming in cancer. Citation Format: Han-Hsi Kuo, You-Yu Lin, Zhao-Jing He, Yu-Chan Chang. ALDOA reprograms stemness and mitochondrial function in lung cancer by facilitating lactylation of mA regulators [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 5373.