Utz, M. | bioRxiv Science

bioRxiv2026

Time-Resolved Profiling: Metabolic Adaptation & Morphology-Specific Drug Response in MCF-7 spheroids

Three-dimensional (3D) tumor models exhibit drug responses that differ from conventional 2D cultures. However, how cellular metabolism dynamically evolves across culture models and during drug treatment remains poorly understood. We compared the responses of MCF-7 cells in 2D and 3D environments to 5-fluorouracil (5-FU), combining {superscript 1}H NMR cellular metabolomics with viable cell counts, the GLUT1-positive population, gene expression, ATP activity, and morphology. Principal component analysis revealed that culture dimensionality, rather than 5-FU treatment, was the primary driver of metabolic flux variation. 3D spheroids exhibited higher glycolytic flux at 72h. Importantly, this elevated glycolysis reflected a higher per-cell flux in larger spheroids rather than an increased cell number. We further observed a higher proportion of GLUT1-positive cells and increased HK2 expression in 3D culture, together with an epithelial phenotype characterized by increased CDH1 and decreased VIM expression. Functionally, 3D displayed maintaining higher cell viability, ATP activity following treatment. Together, these findings suggest that 3D architecture promotes a metabolically defensive phenotype and cellular metabolic behaviors is associated with morphology, which may inform future drug screening model selection. BlurbTime-resolved NMR metabolomics reveals that 3D culture architecture, rather than 5-FU treatment, defines the metabolic phenotype of MCF-7 cells, linking spheroid morphology with per-cell glycolytic activity, ATP preservation, and reduced chemotherapy sensitivity. Synopsis O_FIG O_LINKSMALLFIG WIDTH=197 HEIGHT=200 SRC="FIGDIR/small/740505v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@15cfa5corg.highwire.dtl.DTLVardef@138ca69org.highwire.dtl.DTLVardef@170d0d8org.highwire.dtl.DTLVardef@19f3572_HPS_FORMAT_FIGEXP M_FIG C_FIG Graphical abstract -- Time-resolved metabolic and phenotypic responses of 2D and 3D MCF-7 cultures to 5-fluorouracil. Bullet pointsO_LITime-resolved {superscript 1}H NMR cellular metabolomics combined with multilevel phenotypic readouts reveals that culture dimensionality, rather than 5-FU chemotherapy, is the dominant determinant of metabolic phenotype in MCF-7 breast cancer cells. C_LIO_LI3D spheroids develop a glycolysis-dominant metabolic state with markedly elevated GLUT1 populations and HK2 transcript, accompanied by substantially reduced sensitivity to 5-FU compared with 2D monolayers. C_LIO_LISpheroid morphology correlates with cellular metabolic flux: larger and more elongated spheroids exhibit higher glycolytic activity on a per cell, independent of spheroid cell number. C_LIO_LIThe 3D-defined metabolic state buffers ATP under 5-FU stress and reinforces an epithelial transcriptional program (CDH1{uparrow}, VIM{downarrow}), arguing that culture architecture must be considered when interpreting preclinical drug responses. C_LI

cancer biology↗

bioRxiv2025

Operando Monitoring of Metabolic Fluxes In Cholestatic Murine Liver Tissue Slices By Microfluidic Nuclear Magnetic Resonance

Monitoring metabolism in living tissues with high temporal resolution and broad metabo-lite coverage remains a major challenge. We introduce TISuMR, a microfluidic Lab-on-a-Chip platform that enables continuous, non-invasive operando NMR spectroscopy of live tissue slices. The TISuMR platform replaces the conventional NMR sample tube with a fully integrated microfluidic culture system that maintains tissue viability through dynamic nutrient perifusion, gas exchange via a diffusion membrane, and precise temperature control. Coupled with a custom-designed micro-NMR probe, the platform allows detection of nearly two dozens of metabolites from just 2.5 {micro}L of sample. In a proof-of-concept study, we demonstrate the platforms unique ability to resolve dynamic metabolic fluxes and to monitor, in real time, the onset of chlorpromazine-induced cholestasis in murine liver tissue, with a time resolution of just over three minutes. This approach provides a powerful, minimally disruptive tool for studying tissue metabolism in real time.

bioengineering↗

bioRxiv2018

In Vivo Measurements of the Frequency-Dependent Impedance of the Spinal Cord

Improved knowledge of the electrode-tissue impedance will be useful in optimizing the clinical protocols and resulting efficacy of the existing and emerging approaches to spinal cord stimulation. Toward that end, the complex impedance (amplitude and phase) of in vivo ovine spinal cord tissue was measured at the electrode-pial subdural surface interface from 5 Hz to 1 MHz, and with the bi-polar electrodes oriented both parallel and perpendicular to the rostral-caudal axis of the spinal cord. At stimulation frequencies above 10 kHz, most of the impedance then becomes resistive in nature and the phase diference between the stimulation signal and the resulting current drops to {approx} 10{ring}, thus maximizing power transfer to the tissues. Also, at these higher frequencies, the current pulse maintains significantly greater fidelity to the shape of the stimulation signal applied across the electrodes. Lastly, there were lower impedances associated with parallel as opposed to perpendicular orientation of the electrodes, thus reflecting the effects of fiber orientation within the spinal cord. Impedance differences of this kind have not been reported with epidural stimulation because of the electrical shunting effects of the intervening layer of relatively high conductivity cerebrospinal fluid. These observations provide a quantitative basis for improved models of spinal cord stimulation and suggest certain advantages for direct intradural stimulation relative to the standard epidural approaches. (Some figures in this article are in colour only in the electronic version)

biophysics↗