CTNNB1 , encoding β-catenin protein, is the most frequently altered proto-oncogene in hepatic neoplasms. In this study, we studied the significance and pathological mechanism of CTNNB1 gain-of-function mutations in hepatocarcinogenesis. Activated β-catenin not only triggered hepatic tumorigenesis but also exacerbated Tp53 deletion or hepatitis B virus infection–mediated liver cancer development in mouse models. Using untargeted metabolomic profiling, we identified boosted de novo pyrimidine synthesis as the major metabolic aberration in β-catenin mutant cell lines and livers. Oncogenic β-catenin transcriptionally stimulated AKT2, which then phosphorylated the rate-limiting de novo pyrimidine synthesis enzyme CAD (carbamoyl-phosphate synthetase 2, aspartate transcarbamoylase, dihydroorotase) on S1406 and S1859 to potentiate nucleotide synthesis. Moreover, inhibition of β-catenin/AKT2-stimulated pyrimidine synthesis axis preferentially repressed β-catenin mutant cell proliferation and tumor formation. Therefore, β-catenin active mutations are oncogenic in various preclinical liver cancer models. Stimulation of β-catenin/AKT2/CAD signaling cascade on pyrimidine synthesis is an essential and druggable vulnerability for β-catenin mutant liver cancer.

Germline or somatic loss-of-function mutations of fumarate hydratase (FH) predispose patients to an aggressive form of renal cell carcinoma (RCC). Since other than tumor resection there is no effective therapy for metastatic FH-deficient RCC, an accurate method for early diagnosis is needed. Although MRI or CT scans are offered, they cannot differentiate FH-deficient tumors from other RCCs. Therefore, finding noninvasive plasma biomarkers suitable for rapid diagnosis, screening, and surveillance would improve clinical outcomes. Taking advantage of the robust metabolic rewiring that occurs in FH-deficient cells, we performed plasma metabolomics analysis and identified 2 tumor-derived metabolites, succinyl-adenosine and succinic-cysteine, as excellent plasma biomarkers for early diagnosis. These 2 molecules reliably reflected the FH mutation status and tumor mass. We further identified the enzymatic cooperativity by which these biomarkers are produced within the tumor microenvironment. Longitudinal monitoring of patients demonstrated that these circulating biomarkers can be used for reporting on treatment efficacy and identifying recurrent or metastatic tumors.

The Warburg effect, characterized by excessive lactate production, and transcriptional dysregulation are two hallmarks of tumors. However, the precise influence of lactate on epigenetic modifications at a genome-wide level and its impact on gene transcription in tumor cells remain unclear. In this study, we conducted genome-wide profiling of histone H3 lysine 18 lactylation (H3K18la) in T-cell acute lymphoblastic leukemia (T-ALL). We observed elevated lactate and H3K18la levels in T-ALL cells compared to normal T cells, with H3K18la levels positively associated with cell proliferation. Accordingly, we observed a significant shift in genome-wide H3K18la modifications from T cell immunity in normal T cells to leukemogenesis in T-ALL, correlated with altered gene transcription profiles. We showed that H3K18la primarily functions in active transcriptional regulation and observed clusters of H3K18la modifications resembling super-enhancers. Disrupting H3K18la modification revealed both synergistic and divergent changes between H3K18la and histone H3 lysine 27 acetylation (H3K27ac) modifications. Finally, we found that the high transcription of H3K18la target genes, IGFBP2 and IARS, is associated with inferior prognosis of T-ALL. These findings enhance our understanding of how metabolic disruptions contribute to transcription dysregulation through epigenetic changes in T-ALL, underscoring the interplay of histone modifications in maintaining oncogenic epigenetic stability.

Background: Neuroblastoma (NB), the common extracranial solid tumor in children, is associated with a poor prognosis, particularly in high‐risk patients. MYCN amplification stands as the most prominent molecular hallmark within this high‐risk subgroup. However, MYCN protein is considered “undruggable” due to its lack of a conventional enzymatic binding pocket and its predominant nuclear localization, which precludes targeting by standard small‐molecule inhibitors or antibody‐based therapeutics. Consequently, current therapeutic strategies have achieved limited efficacy against MYCN‐driven NB. Notably, MYCN not only orchestrates diverse metabolic reprogramming pathways in tumors but also exerts a pivotal influence on cellular differentiation. To overcome this therapeutic barrier, we seek to elucidate the contribution of purine metabolism to stemness maintenance in MYCN ‐amplified NBs and to discover novel small‐molecule inhibitors capable of inducing differentiation in high‐risk NBs. Methods: Metabolomic profiling via mass spectrometry was employed to delineate differential metabolite signatures between MYCN ‐amplified and non‐amplified NB cells. Bioinformatics analysis of publicly available RNA sequencing datasets facilitated the systematic evaluation of purine metabolic enzyme expression. Cell differentiation, proliferation, colony formation, and cell migration assays were employed to assess the inhibitor's effects. Additionally, an in vivo xenograft model of NB was established to examine the therapeutic potential of lometrexol (LMX), a selective inhibitor of the purine biosynthesis enzyme phosphoribosylglycinamide formyltransferase (GART). Results: Significant changes in nucleotide metabolism were identified in NB cell lines with high MYCN expression compared to those with low MYCN expression. The expression of purine metabolic enzyme genes was positively correlated with MYCN expression, prognosis, and differentiation status in NBs. Pharmacological inhibition of GART using LMX elicited a robust pro‐differentiation response, concomitant with a significant suppression of tumorigenic potential. Conclusions: These findings establish purine metabolic enzyme inhibition as a viable therapeutic strategy to induce differentiation and attenuate tumor progression in high‐risk MYCN ‐amplified NBs.