Human plasma-like medium facilitates metabolic tracing and enables upregulation of immune signaling pathways in glioblastoma explants

Abstract

Purpose: Metabolism within the tumor microenvironment (TME) represents an increasing area of interest to understand glioma initiation and progression. Stable isotope tracing is a technique critical to the study of tumor metabolism. Cell culture models of this disease are not routinely cultured under physiologically relevant nutrient conditions and do not retain cellular heterogeneity present in the parental TME. Moreover, in vivo, stable isotope tracing in intracranial glioma xenografts, the gold standard for metabolic investigation, is time consuming and technically challenging. To provide insights into glioma metabolism in the presence of an intact TME, we performed stable isotope tracing analysis of patient-derived, heterocellular Surgically eXplanted Organoid (SXO) glioma models in human plasma-like medium (HPLM). Methods: Glioma SXOs were established and cultured in conventional media or transitioned to HPLM. We evaluated SXO cytoarchitecture and histology, then performed spatial transcriptomic profiling to identify cellular populations and differential gene expression patterns. We performed stable isotope tracing with15N2-glutamine to evaluate intracellular metabolite labeling patterns. Results: Glioma SXOs cultured in HPLM retain cytoarchitecture and cellular constituents. Immune cells in HPLM-cultured SXOs demonstrated increased transcription of immune-related signatures, including innate immune, adaptive immune, and cytokine signaling programs.15N isotope enrichment from glutamine was observed in metabolites from diverse pathways, and labeling patterns were stable over time. Conclusion: To enable ex vivo, tractable investigations of whole tumor metabolism, we developed an approach to conduct stable isotope tracing in glioma SXOs cultured under physiologically relevant nutrient conditions. Under these conditions, SXOs maintained viability, composition, and metabolic activity while exhibiting increased immune-related transcriptional programs.

Matched three-dimensional organoids and two-dimensional cell lines of melanoma brain metastases mirror response to targeted molecular therapy

“…They found they could successfully model the immunosuppressive microenvironment and sensitivity to immune checkpoint blockade in vivo [35]. Additionally, we have recently shown the ability to perform stable isotope tracing of glioma SXOs, providing another unique avenue to study tumor metabolism in metastatic cancer of the brain [36].…”

Organoid Intelligence: Bridging Artificial Intelligence for Biological Computing and Neurological Insights

“…This process is tightly regulated by a network of genes and signaling pathways. Disruptions in these processes can lead to a range of neurological and psychiatric disorders, including autism, schizophrenia, and epilepsy [27]. Brain organoids provide a unique platform to study these processes in a controlled laboratory setting.…”