AUTHOR=Tuo Lin , Yan Li Ting , Liu Ying , Wang Shu Qiang , Yang Xing Xiang , An Xiang TITLE=Genetically instrumented circulating metabolites and hepatobiliary cancer risk: A multi-tiered Mendelian randomization and functional interrogation JOURNAL=Frontiers in Oncology VOLUME=Volume 15 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2025.1680865 DOI=10.3389/fonc.2025.1680865 ISSN=2234-943X ABSTRACT=BackgroundHepatobiliary malignancies—including hepatocellular carcinoma and cholangiocarcinoma—are major causes of cancer-related mortality worldwide, yet their regulatory pathways remain incompletely defined.MethodsWe employed a two-sample Mendelian randomization (MR) approach to systematically investigate causal relationships between 1,400 serum metabolites and hepatobiliary cancer risk. Through stringent quality control (all SNPs with F-statistics > 10) and sensitivity analyses (MR-Egger regression, weighted median method, and MR-PRESSO), we identified 10 candidate metabolites.ResultsMeta-analysis confirmed three metabolites with robust associations: risk-increasing dimethylarginine (SDMA+ADMA) and 4-hydroxyhippurate, and protective 3-hydroxyisobutyrate. Multivariable MR validated the independent effects of 4-hydroxyhippurate and 3-hydroxyisobutyrate. In vitro functional experiments demonstrated that 4-hydroxyhippurate promoted, whereas 3-hydroxyisobutyrate inhibited, hepatocellular carcinoma cell proliferation.ConclusionThese findings advance understanding of metabolic dysregulation in hepatobiliary malignancies and nominate candidate diagnostic biomarkers and therapeutic targets, providing translationally relevant hypotheses for precision medicine.