Related Experiment Video
Updated: Oct 16, 2026
Live Imaging to Quantify Cellular Radiosensitivity in Patient-Derived Tumor Organoids
Published on: April 5, 2024
Selective lipid Metabolic remodelling in radiosensitive normal tissues after FLASH radiotherapy
Shuhei Aramaki1, Maxime Dubail2, Mathieu Sertorio3
1Photonic Quantum Therapeutics Laboratory, Institute of Photonics Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Chuo-ku, Hamamatsu, Shizuoka 431-3192, Japan; Department of Radiation Oncology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Chuo-ku, Hamamatsu, Shizuoka 431-3192, Japan; Global Translational Science, Varian, a Siemens Healthineers Company, Palo Alto, CA 94304, the United States of America.
Background And Purpose:
FLASH radiotherapy, delivered at ultra-high dose rates, spares normal tissues while maintaining tumor control, but the molecular basis of this differential response remains poorly defined, particularly at timepoints relevant to tissue repair. We investigated whether lipid metabolism contributes to the FLASH effect in head and neck cancer.
Materials And Methods:
MOC2 tumor-bearing mice received a single 10 Gy fraction of conventional (CONV) or ultra-high dose-rate FLASH protons, with non-irradiated controls (CTRL). Tongue and contralateral tumors were collected two weeks later and analyzed by bulk lipidomics, spatial lipidomics and proteomics. After biochemical filtering, 1,547 lipid species across 37 classes were quantified.
Results:
At two weeks, CONV irradiation was associated with a triglyceride-catabolic, oxidative-stress signature in tongue tissue, marked by loss of the lipid-droplet hydrolase Ces1d alongside induction of the peroxisomal β-oxidation enzyme Acox1. FLASH irradiation was instead associated with a distinct lipid-remodelling signature: suppression of Mgll, induction of Apoe, membrane phospholipid remodelling (increased phosphatidylcholine and phosphatidylethanolamine), and Lypla2 upregulation. Spatial lipidomics provided illustrative spatial context consistent with concentration of these changes in minor salivary gland acini. Tumor tissue showed no comparable modality-specific divergence.
Conclusions:
These correlative multi-omics data indicate that FLASH is associated with remodelling of lipid metabolism in radiosensitive normal tissue, beyond a simple reduction of acute oxidative damage. We propose a Lipid Metabolic Remodelling Hypothesis for testing: the remodelling of lipid metabolism observed after FLASH may contribute to normal-tissue sparing rather than representing solely a downstream consequence of reduced acute oxidative damage. This model complements existing physicochemical models and offers a basis for radioprotection strategies in head and neck radiotherapy.
