Biology subjects

Villar, V. H.

Publications and source records attributed to Villar, V. H..

4 recordsLinked to original sources

bioRxiv2026

Preclinical efficacy and safety of Tegavivint in Wnt-activated hepatocellular carcinoma

Background & AimsHepatocellular carcinoma (HCC), a predominant form of liver cancer, remains a significant clinical unmet need. Given that 30-50% of HCC cases harbour mutations in the Wnt/{beta}-catenin signalling pathway, targeting this cascade represents a promising therapeutic strategy. However, the clinical translation of Wnt inhibitors has been hindered by severe adverse events observed in preclinical models and early-phase clinical trials, primarily due to the essential role of Wnt signalling in maintaining normal tissues such as the intestine and bone. MethodsWe examined the efficacy of Tegavivint, a first-in-class Wnt pathway inhibitor that targets TBL1, against HCC to elucidate its underlying mechanism of action. We evaluated the dose-response of Tegavivint and its effects on the cell cycle, apoptosis, and Wnt target gene expression using HepG2, HUH6, and HUH7 cell lines in vitro. Furthermore, we employed an orthotopic xenograft transplant model using HepG2 cells in immunodeficient mice to assess the safety profile and on-target anti-cancer efficacy of Tegavivint in vivo. ResultsTegavivint exhibited potent Wnt pathway-suppressing effects in cancer cells with constitutive Wnt pathway activation. Notably, Tegavivint displayed robust anti-tumour activity across a broad range of HCC cell lines, regardless of their Wnt pathway activation status. While Tegavivint inhibited the Wnt pathway and triggered the activation of apoptotic pathways in most cell lines, our findings suggest that it also can induce cell death by activating alternative non-apoptotic pathways in apoptosis-resistant cancer cells. In an orthotopic transplant mouse model, Tegavivint significantly downregulated Wnt pathway target genes, inhibited cell proliferation, induced apoptosis and suppressed growth in tumours. ConclusionsTaken together, our data establish a robust foundation for evaluating Tegavivint as a novel therapeutic option, specifically tailored for HCC patients harbouring Wnt-driven hepatic malignancies.

cancer biology↗

bioRxiv2026

L-pentahomoserine correlates with therapy outcome in esophageal cancer and promotes metabolic adaptations that support cell survival under nutrient-deprived conditions

Esophageal adenocarcinoma (EAC) is the sixth-leading cause of cancer-related death. Although pyrimidine analogue-based neoadjuvant and adjuvant therapies are widely used, patient responses remain variable. Emerging evidence indicates that bacteria-derived metabolites influence tumor biology and therapy outcomes. To identify non-canonical plasma metabolites linked to cancer biology, we performed correlation analyses between untargeted metabolomics profiles and overall survival. This approach revealed a bacterial metabolite called L-pentahomoserine, or L-2-amino-5-hydroxypentanoic acid (L-2A5HPA), to be positively associated with overall survival. Notably, L-2A5HPA promoted cell survival under nutrient limitation by redirecting glucose metabolism towards aspartate and pyrimidine biosynthesis. In vitro, L-2A5HPA uptake varied among cell lines and was controlled by stereospecific transporters. Furthermore, metabolic profiling in mouse models of liver cancer showed different levels of L-2A5HPA and a strong correlation with pyrimidine intermediates, dihydroorotate and orotate. The link between L-2A5HPA, pyrimidine nucleotide metabolism, and cell survival provides mechanistic insight into its association with patient outcome. Our findings position L-2A5HPA as a metabolite with potential to become a prognostic biomarker for EAC and underscores its role in metabolic adaptation under nutrient-deprived conditions.

cancer biology↗

bioRxiv2023

Paracrine secretion of MUFAs prevents ferroptosis in triple-negative breast cancer and reveals selenocysteine synthesis dependency for lung metastasis

The limited availability of therapeutic options for patients with triple-negative breast cancer (TNBC) contributes to the high rate of metastatic recurrence and poor prognosis. Ferroptosis is a type of cell death caused by iron-dependent lipid peroxidation and counteracted by the antioxidant activity of the selenoprotein GPX4. Here, we show that TNBC cells secrete an anti-ferroptotic factor in the extracellular environment when cultured at high cell densities but are primed to ferroptosis when forming colonies at low density. We found that secretion of the anti-ferroptotic factors, identified as monounsaturated fatty acid (MUFA) containing lipids, and the vulnerability to ferroptosis of single cells depends on the low expression of stearyl-CoA desaturase (SCD) that is proportional to cell density. Finally, we show that the inhibition of Sec-tRNAsec biosynthesis, an essential step for selenoprotein production, causes ferroptosis and impairs the lung seeding of circulating TNBC cells that are no longer protected by the MUFA-rich environment of the primary tumour.

cancer biology↗

bioRxiv2020

Microbiome-derived metabolites reproduce the mitochondrial dysfunction and decreased insulin sensitivity observed in type 2 diabetes

Diabetes is a global health problem that was estimated to be the 7th leading cause of death worldwide in 2016. Type 2 diabetes mellitus (T2DM) is classically associated with genetic and environmental factors, however recent studies have demonstrated that the gut microbiome, which is altered in T2DM patients, is also likely to play a significant role in disease development. Despite this, the identity of microbiome-derived metabolites that influence T2DM onset and/or progression remain elusive. Here we demonstrate that a serum biomarker for T2DM, previously of unknown structure and origin, is actually two microbiome-derived metabolites, 3-methyl-4-(trimethylammonio)butanoate (3M-4-TMAB) and 4-(trimethylammonio)pentanoate (4-TMAP). These metabolites are produced by the Lachnospiraceae family of bacteria, which are highly prevalent in the gut microbiome of T2DM patients and are associated with high dietary fat intake. Treatment of human liver cells with 3M-4-TMAB and 4-TMAP results in a distinct change in the acylcarnitine profile in these cells and significantly reduced their insulin sensitivity; both indicators of T2DM. These results provide evidence of a mechanistic link between gut microbiome derived metabolites and T2DM.

microbiology↗