Gliomas are the most common brain tumors in adults and the most lethal solid cancer in children younger than 12 years old. Malignant gliomas remain incurable and present unique challenges for clinicians, radiologists, and translational investigators aiming to improve both diagnosis and prognosis. Targeting tumor metabolism has re-emerged over the last decade as a potential source of new cancer therapies. There are several means by which human gliomas metabolism has been assessed: through the metabolome of plasma collected from the cubital vein, through metabolomics analysis of blood collected from resected cancer tissue or cerebral spinal fluid, through imaging with nuclear magnetic resonance (NMR), and through assessment of isotope enrichment in glioma tissue after intraoperative infusion with 13C-labeled nutrients. To date, however, direct measurement of metabolites consumption and production by gliomas in patients is extremely technically difficult.
In a recent study published on Nature Communications, Woo-ping Ge group (woopinglab.org) from Chinese Institute for Brain Research (CIBR) and NanxiangXiong group from Tongji Medical College at Huazhong University of Science and Technology, developed a novel method, named CARVE, paired analysis of Cancer ARterial-VEnous metabolome, to study tumor metabolism directly from patient.
This method is based on the prediction that gliomas consume metabolites from the arterial blood in appreciable quantities, and that these metabolites are present at significantly lower concentrations in venous blood downstream of the glioma. Conversely, metabolites produced and secreted by gliomas accumulate in venous blood downstream of the glioma relative to the arterial supply. Through the comparison of plasma metabolomes between the arterial supply and venous drainage, they could use CARVE to exclude the interpatient variation and characterized multiple metabolites that are consumed and produced by gliomas in vivo from patients.
This is the first time that blood has been successfully collected from an artery and vein specifically upstream and downstream of a tumor in patients for the purpose of performing metabolomic analysis to characterize the uptake and consumption of metabolites from the tumor. Identification of the metabolites or other molecules consumed by gliomas in vivo is beneficial for the understanding of glioma metabolism. It will greatly encourage the scientific community to use a similar strategy to perform metabolomic analysis of other cancers in patients or animal models.