PUF, a biflavone monomer, triggers DNA damage through SLC25A15 downregulation and purine metabolic suppression in DLBCL.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) remains a therapeutic challenge, with a substantial proportion of patients failing to respond to standard regimens. Natural biflavonoids have demonstrated antitumor potential, but their effects on the metabolic vulnerabilities of DLBCL are poorly understood. This study aimed to elucidate the antitumor efficacy and of pulvinatabiflavone (PUF), a novel biflavonoid monomer isolated from Selaginella cuspidata, against DLBCL and the related mechanism. METHODS: The antiproliferative effects of PUF were evaluated in multiple DLBCL cell lines (OCI-LY8, SU-DHL-2, SU-DHL-8, and RIVA) and a xenograft mouse model using CCK-8, flow cytometry (apoptosis/cell cycle), and Western blotting. Metabolomics, transcriptomics, functional rescue experiments (with IMP and dGTP), and SLC25A15 knockdown models were used to investigate the mechanism of PUF. RESULTS: PUF potently inhibited DLBCL cell proliferation (IC₠₀ < 2 μg/ml at 48 h), induced apoptosis, and caused G2/M cell cycle arrest. Multiomics analyses revealed that PUF disrupted purine nucleotide metabolism, leading to critical dGTP depletion and subsequent DNA damage, as evidenced by increased γ-H2AX expression. This DNA damage was ameliorated by supplementation with the purine metabolites IMP or dGTP. PUF was found to downregulate the mitochondrial transporter SLC25A15, which is highly expressed in DLBCL. Molecular docking and cellular thermal shift assay (CETSA) confirmed that PUF directly binds to the mitochondrial transporter SLC25A15. Knockdown of SLC25A15 ameliorated the DNA damage phenotype, which was similarly rescued by dGTP. Importantly, in the xenograft model, PUF treatment not only suppressed tumor growth but also downregulated SLC25A15 and upregulated γ-H2AX in tumor tissues, confirming the mechanism in vivo. CONCLUSIONS: The biflavonoid PUF exerts profound anti-DLBCL effects by directly targeting SLC25A15, disrupting purine nucleotide metabolism, thereby inducing dGTP shortage-mediated DNA damage. Our integrated findings from in silico, cellular, and animal models suggest that PUF is a promising therapeutic candidate and reveal that SLC25A15 is a novel metabolic target in DLBCL. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12967-026-07797-9.