Biology subjects

Vousden, K.

Publications and source records attributed to Vousden, K..

5 recordsLinked to original sources

bioRxiv2026

NAD+ limitation and α-ketoglutarate depletion define cancer induced muscle atrophy

Tumour-host crosstalk is an emerging hallmark of malignancy. It is increasingly recognised that cancer alters non-tumour bearing distant organs, with important consequences for disease progression and survival. Skeletal muscle loss, a defining feature of cancer-associated cachexia, contributes to morbidity and reduced quality of life, yet its underlying mechanisms remain poorly understood. In this study we analysed the secretome of pancreatic cancer cells and identified a metabolite-driven signal that induces myotube atrophy. Our data suggests that atrophy, which seems to involve cytoskeletal stress and increased myosin contractility, arises from cancer cell-dependent reductive metabolic rewiring. Pancreatic cancer cells conditioned their environment with elevated levels of lactate, generating a lactate-rich extracellular milieu that decrease the NAD+/NADH ratio in myotubes. This redox imbalance impaired oxidative metabolism, decreasing -ketoglutarate (KG) levels and disrupted KG-dependent processes. Restoration of NAD+ or KG levels rescued myotube atrophy. Skeletal muscle from cancer-associated cachexia mouse models exhibited reduced KG levels. Collectively, these findings identify a targetable metabolite-mediated mechanism of tumour-muscle crosstalk.

cancer biology↗

bioRxiv2024

Sensing of extracellular L-Proline availability by the integrated stress response determines the outcome of cell competition.

Cell competition is a quality control acting from development to the adult that eliminates cells that are less-fit than their neighbours. How winner cells induce the elimination of losers during this process is poorly understood. Here, we address this question by studying the onset of differentiation in mouse, where cell competition eliminates 35% of embryonic cells. These loser cells have mitochondrial dysfunction, and we find that this causes amino-acid deprivation and activation of the integrated stress response (ISR), a pathway essential for their survival. We show that L-Proline is a key amino-acid sensed by the ISR and that in a competitive environment, winner cells induce increased L-Proline uptake in loser cells. This causes ISR repression and their elimination. Our results imply that cell competition is acting as a nutrient sensor, eliminating dysfunctional cells when amino acids are plentiful but sparing them in nutrient poor environments.

developmental biology↗

bioRxiv2024

p53 and TIGAR promote redox control to protect against metabolic dysfunction-associated steatohepatitis

TP53 is a potent tumour suppressor that coordinates diverse stress response programmes within the cell. The activity of p53 is frequently context and cell type-dependent, and ranges from pro-survival activities, including the implementation of transient cell cycle arrest and metabolic rewiring, through to cell death. In addition to tumour suppressor functions, p53 also has established roles in the pathological response to stress that occurs during tissue damage and repair, including within the liver. Metabolic dysfunction-associated steatohepatitis (MASH) is a major driver of hepatocellular carcinoma (HCC), but our understanding of the molecular determinants of MASH development remains incomplete. Here, using a p53 reporter mouse, we report early and sustained activation of hepatic p53 in response to an obesogenic high fat and high sugar diet. In this context, liver-specific loss of p53 accelerates the progression of benign fatty liver disease to MASH that is characterised by high levels of reactive oxygen species (ROS), extensive fibrosis, and chronic inflammation. Using an in vitro culture system, we show that p53 functions to control ROS and protect against the development of MASH, in part through induction of the antioxidant gene TP53-induced glycolysis and apoptosis regulator (TIGAR). Our work demonstrates an important role for the p53-TIGAR axis in protecting against MASH, and identifies redox control as an essential barrier against liver disease progression.

cancer biology↗

bioRxiv2021

PHGDH is required for germinal center formation and is a therapeutic target in MYC-driven lymphoma

The synthesis of serine from glucose is a key metabolic pathway supporting cellular proliferation in healthy and malignant cells. Despite this, the role that this aspect of metabolism plays in germinal center biology and pathology is not known. Here, we performed a comprehensive characterization of the role of the serine synthesis pathway in germinal center B cells and lymphomas derived from these cells. We demonstrate that upregulation of a functional serine synthesis pathway is a metabolic hallmark of B-cell activation and the germinal center reaction. Inhibition of phosphoglycerate dehydrogenase (PHGDH), the first and rate limiting enzyme in this pathway, leads to defective germinal formation and impaired high-affinity antibody production. In addition, overexpression of enzymes involved in serine synthesis is a characteristic of germinal center B-cell derived lymphomas, with high levels of expression being predictive of reduced overall survival in diffuse large B cell lymphoma. Inhibition of PHGDH induces apoptosis in lymphoma cells reducing disease progression. These findings establish PHGDH as a critical player in humoral immunity and a clinically relevant target in lymphoma.

immunology↗

bioRxiv2018

The ERBB network facilitates KRAS-driven lung tumorigenesis

KRAS is the most frequently mutated driver oncogene in human adenocarcinoma of the lung. There are presently no clinically proven strategies for treatment of KRAS-driven lung cancer. Activating mutations in KRAS are thought to confer independence from upstream signaling, however recent data suggest that this independence may not be absolute. Here we show that initiation and progression of KRAS-driven lung tumors requires input from ERBB family RTKs: Multiple ERBB RTKs are expressed and active from the earliest stages of KRAS driven lung tumor development, and treatment with a multi-ERBB inhibitor suppresses formation of KRasG12D-driven lung tumors. We present evidence that ERBB activity amplifies signaling through the core RAS pathway, supporting proliferation of KRAS mutant tumor cells in culture and progression to invasive disease in vivo. Importantly, brief pharmacological inhibition of the ERBB network significantly enhances the therapeutic benefit of MEK inhibition in an autochthonous tumor setting. Our data suggest that lung cancer patients with KRAS-driven disease may benefit from inclusion of multi-ERBB inhibitors in rationally designed treatment strategies.\n\nOne Sentence SummaryG12 Mutant KRAS requires tonic ERBB network activity for initiation and maintenance of lung cancer

cancer biology↗