Citations

ABSTRACT Background Obesity affects over 40% of the US population and contributes to worse outcomes in a variety of diseases and disorders. Glucagon‐like peptide‐1 receptor agonists have drawn attention for their impact on obesity. With a dense population of receptors throughout the gastrointestinal tract, it is critical to understand the way that glucagon‐like peptide‐1 receptor agonists impact gastrointestinal diseases and disorders. Aims To evaluate the expanding role of glucagon‐like peptide‐1 receptor agonists in the management of obesity and gastrointestinal disease, with a focus on therapeutic applications, impact on gastrointestinal cancers, safety profile, and implications for gastroenterology practice. Methods We conducted a narrative review of recent clinical trials, cohort studies, and guideline updates through 2025. Evidence was synthesised on efficacy, safety, and clinical implications across gastrointestinal disorders including steatotic liver disease, gastroesophageal reflux, inflammatory bowel disease, short bowel syndrome, and obesity‐associated cancers. Results Glucagon‐like peptide‐1 receptor agonists induce substantial and durable weight loss and improve obesity‐related gastrointestinal outcomes. They are approved for steatotic liver disease, with demonstrated histologic and biochemical benefits. Evidence suggests a reduced incidence of several gastrointestinal cancers. The most common adverse events include nausea, vomiting, diarrhoea, constipation, and delayed gastric emptying, which may affect peri‐endoscopic management. Discontinuation rates remain substantial but can be mitigated by careful titration and specialist oversight. Conclusions Glucagon‐like peptide‐1 receptor agonists are a critical therapy for obesity and several related gastrointestinal conditions. Gastroenterologists are uniquely positioned to optimize their use, manage adverse events, coordinate multidisciplinary care, and ensure safe and effective integration into practice.

Abstract Background Short bowel syndrome (SBS) is a chronic condition requiring parenteral nutrition (PN) support and multidisciplinary management. However, disparities in access to care and standardized treatment pathways, in addition to economic burden, remain considerable for patients. Understanding healthcare resource utilization (HCRU) and treatment patterns, especially in relation to patient‐reported outcomes (PROs), is critical for improving care. Methods A cross‐sectional, multiphase study was conducted in 2023. This analysis focuses on phase 3, using a deidentified database that integrated claims and PROs from 68 patients in phase 2. Twenty‐three patients were included in the analytic cohort after applying additional criteria. Descriptive statistics summarized patient demographics, HCRU, and treatment patterns for the overall cohort and stratified by median SBS–quality of life (QoL) score. Results The median age at SBS diagnosis was 35 years, and 91% of patients were female. Patients saw a median of 35 different healthcare providers and underwent approximately five procedures before diagnosis. In the 6 months after diagnosis, 39% had been hospitalized, and 26% had emergency room (ER) visits. Healthcare costs increased after diagnosis, with long‐term PN use accounting for 34% of total costs. Patients with worse QoL had a higher number of ER visits than patients with better QoL. Patients who self‐reported being treated by SBS specialists had lower healthcare costs than patients who did not receive specialized care. Conclusion SBS is associated with high HCRU and costs, particularly for patients with poor QoL. Multidisciplinary care, especially from SBS specialists, may help reduce healthcare costs and improve patient outcomes.

Abstract Background Radiotherapy treatment planning requires knowledge of a patient's anatomical surface for use in dose calculations, collision checks, or surface‐guided radiation therapy (SGRT). This information is usually obtained from a computed tomography (CT) scan which may encounter field‐of‐view (FOV) limitations or require additional radiation dose beyond the treatment area to capture the full patient habitus. Purpose This study demonstrates an affordable alternative solution to obtain a patient's surface information without CT or room mounted surface‐guidance imaging cameras for the purpose of detecting patient collisions and providing additional skin surface information needed for appropriate depth calculations of clipped FOV scans. Methods Three‐dimensional (3D) surface models of five patients were acquired immediately prior to CT simulation using an iPad Air 2 equipped with a Structure Sensor Pro and Monocle SS application. The 3D surfaces were manually registered to the CT images and nearest distances between CT surface and 3D surface were calculated. Nearest distance calculations were also performed with a 2 mm CT rind structure that excluded select regions not relevant to surface detection. To demonstrate the advantage of having additional scan length for clearance checks, a collision simulated plan was evaluated with a shortened CT scan length versus with additional 3D surface information. Results CT rind to 3D scan surface mean distances for each patient were 1.65 mm, 0.99 mm, −0.93 mm, −0.79 mm, and −1.53 mm with standard deviations of 6.51 mm, 6.71 mm, 3.38 mm, 2.84 mm, and 2.69 mm. Conclusion This study demonstrates the feasibility of an accessible low‐cost 3D surface scanning solution to supplement clipped field‐of‐view CT scans and reduce CT scan lengths by obtaining important patient surface data for improved calculation accuracy, treatment clearance checks, and SGRT.

Abstract A new mouse model for the classical subtype of human glioblastoma (GBM) has been bred using Cre-mediated EGFRvIII overexpression and homozygous p19-ARF deletion, the mouse homolog of human p14ARF/CDKN2A, in GFAP expressing cells. Transgenic mice develop intraparenchymal and/or leptomeningeal brain lesions with some spinal cord invasion as early as 1 month old and 95% of mice die by 6 months due to hydrocephalus and/or paralysis. Mice with high grade tumors have worse survival and similar features to human classical GBM such as necrosis, high levels of mitosis and infiltration of tumor cells into normal brain. Immunohistochemical analysis confirms EGFRvIII overexpression and p19-ARF loss in Cre-expressing cells, along with patchy positive GFAP and high proliferation by Ki67. Bulk RNA sequencing reveals GEC3 tumors cluster closely with human classical GBM and have significant upregulation of downstream markers in the JAK/STAT and P13K/AKT pathways. Adherent and neurosphere primary culture of dissociated tumors indicate that tumor cells maintain EGFRvIII expression in culture and generate xenograft tumors by 3 weeks after intracranial injections into NODSCID mice. Xenograft tumors are reminiscent of the primary tumor, with similar histopathological features and immunohistochemical staining. Our spontaneous glioma model is a powerful tool for future studies focused on the role of the immune microenvironment on glioma recurrence and resistance.

Abstract Recurrent or refractory IDH-mutant (mt) gliomas represent a population with significant unmet clinical need. The Notch ligand delta-like 3 (DLL3) is a tumor-associated antigen that is highly and homogeneously expressed in IDH-mt gliomas but absent in normal brain tissue, making it an attractive therapeutic target. Tarlatamab is a half-life extended bispecific T-cell engager that targets DLL3 and CD3 to redirect cytotoxic T cells toward DLL3-expressing tumor cells. Given the specific expression of DLL3 in IDH-mt gliomas and promising activity of tarlatamab in other DLL3-positive tumors, this study investigates the safety, efficacy, and intracranial activity of tarlatamab in this patient population. TARGID is an open-label, phase II trial enrolling adult patients with histologically confirmed IDH1 or IDH2-mt astrocytoma or oligodendroglioma following up to two prior lines of systemic therapies. The study comprises two cohorts. Cohort 1 (n=10) includes patients with resectable disease who will receive up to three cycles of tarlatamab prior to surgery; postoperative continuation is permitted. The primary endpoint for this cohort is the change in CD8+ T-cell infiltration in tumor tissue and blood. Cohort 2 (n=34) includes patients with unresectable disease and uses a Simon’s optimal two-stage design (H0: P ≤ 0.1 versus H1: P ≥ 0.25). In the 1st stage, 13 patients will be accrued. If 2 or more responses are observed, 21 additional patients will be enrolled. Tarlatamab is administered intravenously at 10 mg every two weeks, following a 1 mg priming dose on Cycle 1 Day 1. The primary endpoint is objective response rate by RANO 2.0. Exploratory endpoints include DLL3 expression, circulating biomarkers, and immune correlatives. The trial is currently in activation, with first patient enrollment anticipated in Q3 2025. The study is supported by the provision of study drug from Amgen as an investigator-initiated trial.

Abstract The brain avidly consumes glucose to fuel neurophysiology. Cancers of the brain, such as glioblastoma (GBM), relinquish physiological integrity and gain the ability to proliferate and invade healthy tissue. How brain cancers rewire glucose utilization to drive aggressive growth remains elusive. Here, we infused 13C-labeled glucose into patients and mice with brain cancer, coupled with quantitative metabolic flux analysis, to map the fates of glucose-derived carbon in tumor vs. cortex. Through the first direct and comprehensive measurements of carbon and nitrogen labeling in both cortex and glioma tissues, we uncover profound metabolic transformations. In human cortex, glucose carbons fuel essential physiologic processes including TCA cycle oxidation and neurotransmitter synthesis. Conversely, gliomas downregulate these processes and scavenge alternative carbon sources such as amino acids from the environment, repurposing glucose-derived carbons to generate molecules needed for proliferation and invasion. Targeting this metabolic rewiring in mice through dietary amino acid modulation selectively alters GBM metabolism, slows tumor growth, and augments the efficacy of standard-of-care treatments. These findings illuminate how aggressive brain tumors exploit glucose to suppress normal physiological activity in favor of malignant expansion and offer potential therapeutic strategies to enhance treatment outcomes.

Abstract High-grade glioma (HGG) continues to have a dismal prognosis owing in part to its heterogeneous and invasive nature both within and between patients. The most aggressive form of high-grade glioma, called glioblastoma, portends a median survival of around 15 months. Like many cancers, high-grade glioma rewires metabolism towards its own benefit, shifting away from the typical reliance of brain tissue on glucose towards other sources such as fatty acids and acetate. Using a cohort of image-localized high-grade glioma biopsies collected from diverse imageable regions with associated transcriptomics (58 patients, 202 biopsies), we are able to assess the spatial transcriptomic landscape of HGG. We have previously shown that the transcriptome of HGG can be characterized into a continuous transition between states, and we have shown that the cellular ecosystem follows a similar pattern, using a combination of trajectory inference and cellular deconvolution. These patterns are strongly associated with the non-enhancing and contrast-enhancing regions of the tumors, which are typically considered for treatment planning and progression assessment. Here, we applied differential expression of hallmark pathways to determine how metabolism factors into this paradigm. As expected, we find overall higher levels of metabolism-associated pathway expression in the contrast enhancing regions compared to the non-enhancing regions. Interestingly, we found metabolic expression differs between the ecologies associated with transcriptional subtypes of high-grade glioma. For example, fatty acid (p=0.003), xenobiotic (p<0.0001) and heme (p<0.0001) metabolism pathways were significantly upregulated for mesenchymal tumor samples, while significantly downregulated for proliferative tumor samples (p=0.02, p<0.0001, p<0.0001, respectively). As we continue to further understand the complex spatial and temporally heterogeneous landscape of these aggressive tumors, it is important to consider the metabolites on which they depend, to better inform prognosis and develop new treatments.

Abstract Glioblastoma (GBM), the most common malignant primary brain tumor in adults, has a median survival of 15 months and 5-year survival rate of only 6.9%. Standard of care, including radiation and chemotherapy, can induce cellular senescence in the brain. The senescence-associated secretory phenotype (SASP) significantly affects glioma microenvironment as these secreted factors exhibit both anti-and pro-tumorigenic effects. However, it is currently unknown whether senescence in the surrounding GBM microenvironment could be beneficial or detrimental to tumor outcomes. Using cell-specific proteomics, we identified upregulation of cathepsin B (CTSB) expression in patient-derived brain tumor initiating cells (BTICs) co-cultured with human fetal neural progenitor cells (NPCs). In matched patient tumor biopsies, sequencing of lateral ventricle (LV)-proximal regions revealed increased CTSB expression compared to LV-distal counterparts. Remarkably, LV-proximal GBMs induced a senescent phenotype and reduced differentiation in subventricular zone (SVZ) NPCs through CTSB secretion. We hypothesize that senescent NPCs in the SVZ contribute to a pro-tumorigenic microenvironment that promotes tumor aggressiveness in LV-proximal GBM. To model this in vitro, senescence was induced in NPCs using recombinant CTSB (100 nM) and hydrogen peroxide (250 µM, 2 hours). Treated NPCs showed increased β-galactosidase activity and increased expression of SASP factors IL-1α, IL-6, and CTSB. Senescent NPCs significantly increased BTIC migration and proliferation (p<0.05) both in co-culture and through conditioned media, suggesting this effect may be mediated by soluble factors. These findings support the hypothesis that senescent NPCs promote BTIC malignancy in LV-proximal GBM and identify CTSB as a potential mediator of this interaction.

Abstract INTRODUCTION Glioblastoma (GBM) contains metabolically distinct cell lineages: treatment-sensitive cells (TSCs) dependent on glycolysis and treatment-resistant persister cells (TRPCs) reliant on lipid metabolism. Our integrative systems biology approach, combining spatial multi-omics and targeted analyses, uncovers lipid acquisition in TRPCs as a pivotal driver of GBM progression which is supported by a retrospective study of statin-treated patients, providing clinical evidence for the therapeutic potential of targeting lipid metabolism in GBM patients stratified based on high TRPC signatures. METHODS We applied spatial transcriptomics and proteomics combined with 3D reconstruction of the tumor microenvironment to map TRPC- and TSC-enriched regions. Immunohistochemically stained tissues were analyzed using CellProfiler and our custom SNAQ algorithm for single-cell neighborhood analysis. Lipid transfer from Tumor-Associated Myeloid Cells (TAMCs) to TRPCs was tracked via flow cytometry, holotomography, and time-lapse imaging. Genetic and pharmacological targeting of CCR2, CSF1R, and FABP3 was performed in vitro and in vivo. Finally, a retrospective analysis of 4,085 GBM patients assessed the impact of statin treatment in relation to TRPC signatures. RESULTS TRPCs exploit recruited TAMCs to acquire lipids, supporting their survival and immune evasion. These interactions are mediated by CCL2/7–CCR2 and CSF1–CSF1R signaling. Disruption of TRPC-TAM lipid homeostasis significantly remodeled the immune microenvironment, reduced tumor growth, and extended survival in preclinical models. Patients with high TRPC signatures typically had poor outcomes; however, retrospective analysis revealed that statin treatment was associated with improved survival in this subgroup. These findings position lipid trafficking as a metabolic vulnerability in GBM and highlight the therapeutic relevance of targeting TRPC–TAMC interactions. CONCLUSION Our study reveals lipid trafficking to TRPCs as a key mechanism driving GBM progression. Targeting TAMC-mediated lipid transfer disrupts immune suppression and tumor growth. Transcriptomic profiling may guide patient stratification, identifying those likely to benefit from lipid metabolism-targeted therapies such as statins.