FGFR1 suppresses ovarian cancer progression by modulating SIRT3-dependent lactylation and metabolic reprogramming

Ovarian cancer (OC) is an aggressive gynecological malignancy with poor prognosis, largely due to late-stage diagnosis and high metastatic potential. However, the functional role and regulatory mechanisms of fibroblast growth factor receptor 1 (FGFR1) in OC remain incompletely understood. In this study, we investigated the expression pattern and biological function of FGFR1 in OC and explored its underlying molecular mechanisms. FGFR1 expression was analyzed using TCGA, GTEx, and tissue microarray datasets, and its prognostic significance was evaluated by Kaplan-Meier survival analysis. Functional assays were performed in OVCAR-3 and SK-OV-3 cells following FGFR1 knockdown or overexpression to assess cell proliferation, migration, invasion, and metabolic activity, including extracellular acidification rate (ECAR) and oxygen consumption rate (OCR). Lactate production and histone lactylation were measured by biochemical assays and Western blotting. Protein interaction between FGFR1 and SIRT3 was examined by co-immunoprecipitation and immunofluorescence, and rescue experiments were conducted to determine SIRT3 dependency. In vivo subcutaneous xenograft models were used to evaluate the role of FGFR1 in tumor growth. We found that FGFR1 expression was significantly reduced in OC tissues and that low FGFR1 levels were associated with unfavorable clinical outcomes. Functionally, FGFR1 silencing promoted OC cell proliferation, migration, invasion, and metabolic activity, whereas FGFR1 overexpression exerted inhibitory effects. Mechanistically, FGFR1 interacted with SIRT3 and stabilized its protein expression. Importantly, SIRT3 knockdown abrogated the FGFR1-mediated reductions in lactate production, glycolytic enzyme expression, ATP levels, and histone lactylation, indicating that FGFR1 regulates metabolic reprogramming through a SIRT3-dependent mechanism. Consistently, FGFR1 knockdown promoted the formation of larger and more invasive tumors in vivo. Collectively, these findings demonstrate that FGFR1 functions as a context-dependent tumor suppressor in OC by modulating SIRT3-mediated metabolic reprogramming and histone lactylation, suggesting that targeting the FGFR1-SIRT3 axis may represent a potential therapeutic strategy for ovarian cancer.