Output
(last update Dec 10th, 2025)
Summary of the findings
Identification of metabolic targets accounting for acquired radioresistance in human breast cancer models. Among the different adaptations that confer resistance to X-rays, cancer stem cells recently emerged as potential drivers of tumor recurrence and metastasis, making them a primary target for anticancer therapy. In a first unpublished study, we investigated how cancer stem cells and their metabolic plasticity could control radioresistance. For that aim, MDA-MB-231 human breast cancer cells were exposed to clinically relevant fractionated irradiation schemes of X-ray irradiation over time to obtain radioresistant (RR) cells, which was confirmed by colony formation assays. Although X-ray-irradiated cell lines show modified mitochondrial features, only RR cells expressed cancer stem-cell markers, including increased MYC gene and protein expression. Increased c-Myc expression and transcriptional activity was also observed in MCF7 RR cells that we produced using an alternative irradiation protocol. Among the various c-Myc inhibitors that we tested, KPT-65661 was found to be the most effective to decrease RR cell proliferation. Combining this inhibitor with X-ray irradiation decreased RR cell survival and tumor growth in vivo. However, it did not affect cancer cell sensitivity to proton radiotherapy. These finding were paralleled by a second unpublished study where we extended the metabolic characterization of wild-type and RR cells. Seahorse oximetry revealed that MDA-MB-231-RR cells were more oxidative than parental radiosensitive cells. Moreover, RNA sequencing allowed us to identify metabolic and stemness-related genes that correlated with patient outcome and could be responsible for acquired radioresistance. Independent RT-qPCR and western blotting confirmed the upregulation of 3 genes of interest in RR cells: glycolytic enzyme ALDOC, preprotein subunit of inhibin/activin INHBB, and transcription factor FOXA1. Using shRNAs and CRISPRi/CRISPRa approaches, we found that high INHBB expression accounted for radioresistance in RR cells. This protein can form activin or inhibin dimers,2 among which we have evidence at the transcriptional level (SMAD4 activation) that activin acts autocrinally on human breast cancer cells to render them radioresistant. We are currently testing activin receptor inhibitors as a new radiosensitizing strategy for both X-ray and proton radiotherapy.
Identification of new pharmacological strategies targeting oxidative phosphorylation to radiosensitize tumors. In a published study,3 we reported that MitoQ, a mitochondria-targeted agent,4 is a radiosensitizer that disrupts the electron flux at the electron transport chain (ETC) of several different cancer cell types. This was not a class effect, as other mitochondria-targeted antioxidants (MitoTEMPO and SKQ1) did not reduce mitochondrial oxygen consumption. Mechanistically, MitoQ blocked electron transfer to ETC Complex III, creating an oxygen sparing that radiosensitized human cancer cells in 2D, 3D and orthotopic models in mice. Importantly, tumors treated with MitoQ to prime fractionated radiotherapy did not regrow, and MitoQ further repressed irradiation-induced cancer cell migration and invasion.5 MitoQ already successfully passed Phase I clinical trials in humans with limited toxicity6 and is currently tested in Phase II and III clinical trials for other pathologies than cancer, making this drug a promising radiosensitizing agent for future clinical applications. We submitted a patent application for that aim, and further investigated mitochondria-targeted antioxidant mito-meformin7,8 and statins9 as additional radiosensitizers in models of human prostate cancer, with interesting radiosensitizing effects. We then investigated the contribution of mitochondrial reactive oxygen species (mtROS) to human breast cancer cell radiosensitivity using mitochondrial-targeted nitropyridine derivative Mito-NPH, designed to both induce mtROS production and inhibit ETC Complex I-dependent oxygen consumption. By dynamically monitoring mtROS generation and oxygen consumption rates (OCRs) in MDA-MB231 and MCF7 cells in vitro and in vivo, we were able to synchronize X-ray irradiation with either the peak of mtROS production or maximal tumor reoxygenation. Pretreatment with Mito-NPH consistently enhanced radiosensitivity under both normoxic and hypoxic conditions, with early mtROS induction driving apoptosis, ferroptosis, and cell cycle arrest associated to a perturbation of the autophagic flux. In vivo, X-ray irradiation delivered at the peak of mtROS production or maximal reoxygenation significantly delayed tumor growth, demonstrating that mtROS provide radiosensitizing effects independently of oxygen availability. Collectively, our studies identified MitoQ and Mito-NPH as pharmacological radiosensitizers, highlighting mitochondrial targeting as a promising strategy for future applications.
Identification and validation of a new technological approach to discriminate between global ROS and mtROS production in vivo. Because the precise site of ROS production plays an important role in cellular redox signaling and its (patho)physiological consequences, we developed EPR and dual nitroxide sensors composed of mitoTEMPO and carbamoyl-proxyl (3CP) to probe ROS production in mitochondrial and intracellular/extracellular compartments, respectively.10 For the proof-of-concept, the decay rates of the nitroxides were measured in 4T1 mouse breast tumor models, both in vitro and in vivo. To modulate the level of ROS either in the cytosol or in the mitochondria, cells and mice were treated with either glutathione synthesis inhibitor L-BSO or ETC Complex III inhibitor antimycin A. In mice, an increase in relative decay rate was observed for 3CP, but not for mitoTEMPO, 1 and 2 days after starting L-BSO treatment, while the opposite result was obtained after antimycin A treatment. These observations were consistent with results obtained on cells in vitro. Blood wash-out did not play a role in the decay of the nitroxide signal. In addition, overexpression of mitochondrial superoxide dismutase 2 (SOD2) allowed the assessment of the contribution of superoxide production to EPR signal decay. Overall, we identified a new protocol to noninvasively identify the site of ROS production in tumors in in vivo.
Identification that iron oxide nanoparticles radiosensitize cancer cells by weakening redox defenses. Still in the context of X-ray radiotherapy, we characterized the radiosensitizing effect of two iron oxide nanoparticle (IONP) formulations (7 nm carboxylated IONPs and PEG5000-IONPs) on A549 human lung carcinoma cells exposed to 225 kV of X-rays.11 Nanoparticles exhibited a radiosensitizing effect through inhibiting detoxification enzymes. In particular, a good correlation between the amplification effect at 2 Gy and the residual activity of thioredoxin reductase was observed, which was consistent with previous observations made for gold nanoparticles. Our study thus emphasized that IONP-induced radiosensitization does not result solely from physical phenomena, but also from biological events that we currently investigate.
Identification that ultra-high dose rate proton radiotherapy induces cellular senescence in nonmalignant cells. Because our metabolic studies did not identify a metabolic control of cancer cell resistance to proton therapy, we extended our investigation to nonmalignant cells. Irradiation can indeed damage healthy tissues around a tumor, with senescence induction as a notable side effect. In a recently published study,12 we compared the effects of X-rays to protons at conventional (2 Gy/min) and ultra-high (454 Gy/s) dose rates on primary normal human dermal fibroblasts. Ultra-high dose rate protons caused more pronounced cellular and nuclear morphological changes than irradiation with conventional protons or X-rays. All three types of irradiations induced an increase in the proportion of senescence-associated β-galactosidase-positive cells, an irreversible cell cycle arrest and an accumulation of unrepaired DNA damage, but none affected the senescence-associated secretory phenotype. This study calling for caution with use of ultra-high dose rate proton irradiation was paralleled by clinical efforts to optimize dose delivery13-17 and healthy tissue sparing18 during proton radiotherapy.
PhD theses
- BLACKMAN Marine. Director: Pierre Sonveaux (PhD thesis obtained 03/2023)
- BRUSTENGA Chiara. Director: Raphaël Frédérick, co-Director: Pierre Sonveaux (PhD thesis obtained 06/2024)
- d'HOSE Donatienne. Director: Bernard Gallez, co-Director: Bénédicte Jordan (PhD thesis obtained 11/2021)
- MATHIEU Barbara. Director: Bernard Gallez, co-Director: Pierre Sonveaux (PhD thesis obtained 12/2025)
- RONDEAU Justin. Director: Pierre Sonveaux (PhD thesis obtained 11/2024)
- ZAMPIERI Luca. Director: Pierre Sonveaux (PhD thesis obtained in 2022)
- COLAUZZI Ilaria. Director: Pierre Sonveaux (ongoing)
- HARDY Eleonore. Director: Anne-Catherine Heuskin, co-Director: Edmond Sterpin (ongoing)
- SAVOYEN Perrine. Director: Raphaël Frédérick, co-Director: Pierre Sonveaux (ongoing)
- VAN DE VELDE Justine. Director: Pierre Sonveaux (ongoing)
- VANDENSANDE Yasmine. Director: Bernard Gallez, co-Director: Pierre Sonveaux (ongoing)
Undergraduate theses
- CHATT Nadir. Director: Bernard Gallez (2022)
- BOUIDIDA Yasmine. Director: Pierre Sonveaux (2024)
- MELLOUL Samia. Director: Bernard Gallez (2024)
Peer-reviewed publications (those acknowledging ARC are marked with a *)
2021 (from 01/10)
Lesari S, Leclercq I, Joudiou N, Komuta M, Daumerie A, Ambroise J, Dili A, Feza-Bingi N, Xhema D, Bouzin C, Gallez B, Pisani F, Bonaccorsi-Riani E, Gianello P. Selective HIF stabilization alleviates hepatocellular steatosis and ballooning in a rodent model of 70% liver resection. Clin Sci (Lond). 2021;135:2285-2305.
*Zampieri LX, Sboarina M, Cacace A, Grasso D, Thabault L, Hamalin L, Vazeille T, Dumon E, Rossignol R, Frédérick R, Sonveaux E, Lefranc F, Sonveaux P. Olaparib is a mitochondrial Complex I inhibitor that kills temozolomide-resistant human glioblastoma cells. Int. J. Mol. Sci. 2021;22:11938.
Cappellesso F, Orban MP, Shirgaonkar N, Berardi E, Serneels J, Neveu MA, Di Molfetta D, Piccapane F, Caroppo R, Debellis L, Ostyn T, Joudiou N, Mignion L, Richiardone E, Jordan BF, Gallez B, Corbet C, Roskams T, DasGupta R, Tejpar S, Di Matteo M, Taverna D, Reshkin SJ, Topal B, Virga F, Mazzone M. Targeting the bicarbonate transporter SLC4A4 overcomes immunosuppression and immunotherapy resistance in pancreatic cancer. Nat Cancer. 2022;3:1464-1483.
Vander Veken L, Dechambre D, Sterpin E, Souris K, Van Ooteghem G, Aldo Lee J, Geets X. Incorporation of tumor motion directionality in margin recipe: the directional MidP strategy. Phys Med. 2021;91:43-53.
2022
*Thabault L, Brustenga C, Savoyen P, Van Gysel M, Wouters J, Sonveaux P, Frederick R, Liberelle M. Discovery of small molecules interacting at lactate dehydrogenases tetrameric interface using a biophysical screening cascade. Eur. J. Med. Chem. 2022;230:114102.
*Ippolito L, Sonveaux P, Chiarugi P. Unconventional roles of lactate along the tumor and immune landscape. Trends Endocrinol. Metabol. 2022;33(4):231-235.
Kemps H, Dessy C, Dumas L, Sonveaux P, Alders L, Van Broeckhoven J, Perez Font L, Lambrichts S, Foulquier S, Hendrix S, Brone B, Lemmens R, Bronckaers A. Extremely low frequency electromagnetic stimulation reduces ischemic stroke volume by improving central collateral blood flow. J. Cereb. Blood Flow Metab. 2022;42:979-996.
*Capeloa T, Krzystyniak J, d’Hose D, Canas Rodriguez A, Payen VL, Zampieri LX, Van de Velde J, Benyahia Z, Pranzini E, Vazeille T, Fransolet M, Bouzin C, Brusa D, Michiels C, Gallez B, Murphy MP, Porporato PE, Sonveaux P. MitoQ inhibits human breast cancer cell migration, invasion and clonogenicity. Cancers 2022;14:1516.
*Capeloa T, Krzystyniak J, Canas Rodriguez A, Payen VL, Zampieri LX, Pranzini E, Derouane F, Vazeille T, Bouzin C, Duhoux FP, Murphy MP, Porporato PE, Sonveaux P. MitoQ prevents human breast cancer recurrence and lung metastasis in mice. Cancers 2022;14:1488.
Macchi C, Moregola A, Greco MF, Svecla M, Bonacina F, Dhup S, Dadhich RK, Audano M, Sonveaux P, Mauro C, Mitro N, Ruscica M, Norata GD. Monocarboxylate transporter 1 deficiency impacts CD8 + T lymphocytes proliferation and recruitment to adipose tissue during obesity. iScience 2022;25(6):104435.
Weber DD, Aminzadeh-Gohari S, Thapa M, Redtenbacher AS, Catalano L, Capeloa T, Vazeille T, Emberger M, Felder TK, Feichtinger RG, Koelblinger P, Dallmann G, Sonveaux P, Lang R, Kofler B. Ketogenic diets slow melanoma growth in vivo regardless of tumor genetics and metabolic plasticity. Cancer Metab. 2022;10(1):12.
Blackman MCN, Capeloa T, Rondeau JD, Zampieri LX, Benyahia Z, Van de Velde J, Fransolet M, Daskalopoulos EP, Michiels C, Beauloye C, Sonveaux P. Mitochondrial protein Cox7b is a metabolic sensor driving brain-specific metastasis of human breast cancer cells. Cancers 2022;14:4371.
*D’Hose D, Mathieu B, Mignion L, Hardy M, Ouari O, Jordan BF, Sonveaux P, Gallez B. EPR Investigations to study the impact of mito-metformin on the mitochondrial function of prostate cancer cells. Molecules 2022;27(18):5872.
*D’Hose Donatienne, Mignion Lionel, Hamelin L, Sonveaux P, Jordan BF, Gallez B. Statins alleviate tumor hypoxia in prostate cancer models by decreasing oxygen consumption: an opportunity for radiosensitization? Biomolecules 2022;12(10):1418.
*Capeloa T, Van de Velde J, d’Hose D, Lipari SG, Derouane F, Hamelin L, Bedin M, Vazeille T, Duhoux FP, Murphy MP, Porporato PE, Gallez B, Sonveaux P. Inhibition of mitochondrial redox signaling with mitoQ prevents metastasis of human pancreatic cancer in mice. Cancers 2022;14(19):4918.
*Farah C, Neveu MA, Yelek C, Bouzin C, Gallez B, Baurain JF, Mignion L, Jordan BF. Combined HP 13C pyruvate and 13C-glucose fluxomic as a potential marker of response to targeted therapies in YUMM1.7 melanoma xenografts. Biomedicines 2022;10:717.
Gossuin Y, Gallez B. Editorial for "Phase I Randomized Trial of 17 O-Labeled Water: Safety and Feasibility Study of Indirect Proton MRI for the Evaluation of Cerebral Water Dynamics": old concepts, new applications. J Magn Reson Imaging. 2022;56:1883-1884.
Buyse C, Joudiou N, Warscotte A, Richiardone E, Minion L, Corbet C, Gallez B. Evaluation of syrosingopine, an MCT inhibitor, as potential modulator of tumor metabolism and extracellular acidification. Metabolites 2022 Jun 17;12(6):557.
d'Hose D, Gallez B. Measurement of mitochondrial (dys)function in cellular systems using electron Paramagnetic Resonance (EPR): Oxygen Consumption Rate and Superoxide Production. Methods Mol Biol 2022;2497:83-95.
Gallez B. The role of imaging biomarkers to guide pharmacological interventions targeting tumor hypoxia. Front Pharmacol. 2022;13:853568.
Saade G, Bogaerts E, Chiavassa S, Blain G, Delpon G, Evin M, Ghannam Y, Haddad F, Haustermans K, Koumeir C, Macaeva E, Maigne L, Mouchard Q, Servagent N, Sterpin E, Supiot S, Potiron V. Ultrahigh-dose-rate proton irradiation elicits reduced toxicity in zebrafish embryos. Adv Radiat Oncol. 2022;8:101124.
*Terwagne M, Nicolas E, Hespeels B, Herter L, Virgo J, Demazy C, Heuskin AC, Hallet B, Van Doninck K. DNA repair during nonreductional meiosis in the asexual rotifer Adineta vaga. Sci Adv. 2022;8:eadc8829.
Borderías-Villarroel E, Taasti V, Van Elmpt W, Teruel-Rivas S, Geets X, Sterpin E. Evaluation of the clinical value of automatic online dose restoration for adaptive proton therapy of head and neck cancer. Radiother Oncol. 2022;170:190-197.
Barragán-Montero A, Bibal A, Dastarac MH, Draguet C, Valdés G, Nguyen D, Willems S, Vandewinckele L, Holmström M, Löfman F, Souris K, Sterpin E, Lee JA. Towards a safe and efficient clinical implementation of machine learning in radiation oncology by exploring model interpretability, explainability and data-model dependency. Phys Med Biol. 2022;67:11TR01.
van der Heyden B, Heymans SV, Carlier B, Collado-Lara G, Sterpin E, D'hooge J. Deep learning for dose assessment in radiotherapy by the super-localization of vaporized nanodroplets in high frame rate ultrasound imaging. Phys Med Biol. 2022;67:115015.
Toumia Y, Pullia M, Domenici F, Facoetti A, Ferrarini M, Heymans SV, Carlier B, Van Den Abeele K, Sterpin E, D'hooge J, D'Agostino E, Paradossi G. Ultrasound-assisted carbon ion dosimetry and range measurement using injectable polymer-shelled phase-change nanodroplets: in vitro study. Sci Rep. 2022;12:8012.
Wuyckens S, Saint-Guillain M, Janssens G, Zhao L, Li X, Ding X, Sterpin E, Lee JA, Souris K. Treatment planning in arc proton therapy: Comparison of several optimization problem statements and their corresponding solvers. Comput Biol Med. 2022;148:105609.
Elhamiasl M, Salvo K, Poels K, Defraene G, Lambrecht M, Geets X, Sterpin E, Nuyts J. Low-dose CT allows for accurate proton therapy dose calculation and plan optimization. Phys Med Biol. 2022;67:195015.
Draguet C, Barragán-Montero AM, Vera MC, Thomas M, Populaire P, Defraene G, Haustermans K, Lee JA, Sterpin E. Automated clinical decision support system with deep learning dose prediction and NTCP models to evaluate treatment complications in patients with esophageal cancer. Radiother Oncol. 2022;176:101-107.
Wuyckens S, Zhao L, Saint-Guillain M, Janssens G, Sterpin E, Souris K, Ding X, Lee JA. Bi-criteria Pareto optimization to balance irradiation time and dosimetric objectives in proton arc therapy. Phys Med Biol. 2022;67(24):245017.
Badiu V, Souris K, Buti G, Villarroel EB, Lambrecht M, Sterpin E. Improved healthy tissue sparing in proton therapy of lung tumors using statistically sound robust optimization and evaluation. Phys Med. 2022;96:62-69.
2023
Buti G, Shusharina N, Ajdari A, Sterpin E, Bortfeld T. Exploring trade-offs in treatment planning for brain tumor cases with a probabilistic definition of the clinical target volume. Med Phys. 2023;50:410-423.
Ternad I, Penninckx S, Lecomte V, Vangijzegem T, Conrard L, Lucas S, Heuskin AC, Michiels C, Muller RN, Stanicki D, Laurent S. Advances in the mechanistic understanding of iron oxide nanoparticles' radiosensitizing properties. Nanomaterials (Basel). 2023;13:201.
*Gallez B, Mathieu B, Sonveaux P. About metformin and its action on the mitochondrial respiratory chain in prostate cancer. Transl Androl Urol 2023;13:909-914.
Borderias-Villarroel E, Fredriksson A, Cvilic S, Di Perri D, Longton E, Pierrard J, Geets X, Sterpin E. Dose mimicking based strategies for online adaptive proton therapy of head and neck cancer. Phys Med Biol. 2023;68(10):105002.
Borderias-Villarroel E, Huet Dastarac M, Barragán-Montero AM, Helander R, Holmstrom M, Geets X, Sterpin E. Machine learning-based automatic proton therapy planning: Impact of post-processing and dose-mimicking in plan robustness. Med Phys. 2023;50(7):4480-4490.
Deffet S, Hamaide V, Sterpin E. Definition of dose rate for FLASH pencil-beam scanning proton therapy: A comparative study. Med Phys. 2023;50(9):5784-5792.
2024
*Rondeau JD, Lipari S, Mathieu B, Beckers C, Van de Velde JA, Mignion L, Da Silva Morais M, Kreuzer M, Colauzzi I, Capeloa T, Pruschy M, Gallez B, Sonveaux P. Mitochondria-targeted antioxidant MitoQ radiosensitizes tumors by decreasing mitochondrial oxygen consumption. Cell Death Discov 2024;10(1):514.
*Rondeau JD, Van de Velde JA, Bouidida Y, Sonveaux P. Subclinical dose irradiation triggers human breast cancer migration via mitochondrial reactive oxygen species. Cancer Metab. 2024;12(1):20.
Scarmelotto A, Delprat V, Michiels C, Lucas S, Heuskin AC. The oxygen puzzle in FLASH radiotherapy: A comprehensive review and experimental outlook. Clin Transl Radiat Oncol. 2024 ;49:100860.
Daisne JF, Isebaert S, Geets X, Donnay L, Sterpin E. Protontherapy : principles, advantages, limitations, indications, perspectives...and some Belgian peculiarities. Rev Med Liege. 2024;79(S1):9-15.
Conq J, Joudiou N, Préat V, Gallez B. Exploring the impact of irradiation on glioblastoma blood-brain-barrier permeability: Insights from dynamic-contrast-enhanced-MRI and histological analysis. Biomedicines. 2024;12(5):1091.
2025
*Mathieu B, Rondeau JD, Mignion L, Sonveaux P, Gallez B. Noninvasive in vivo discrimination between mitochondrial ROS and global ROS production in solid tumors using EPR spectroscopy. Redox Biol 2025;87:103871.
*De Meester ME, Paulus H, Michiels C, Heuskin AC, Debacq-Chainiaux F. Senescence under the lens: X-ray vs. proton irradiation at conventional and ultra-high dose rate. Radiat Res. 2025;204(5):467-476.
Capeloa T, Van de Velde JA, Pranzini E, Ippolito L, Zampieri LX, Tardy M, Vazeille T, Provito A, Carrà G, Scalera A, Payen VL, Porporato PE, Sonveaux P. Mitochondrial ROS inhibition prevents doxorubicin-induced breast cancer cell migration and invasion. iScience 2025;28(8):113031.
Bogaerts E, Saade G, Macaeva E, Chiavassa S, Evin M, Haddad F, Isebaert S, Koumeir C, Mouchard Q, Potiron V, Servagent N, Supiot S, Sterpin E, Haustermans K. A comprehensive mechanistic study on the proton FLASH sparing effect in zebrafish embryos: From DNA damage to developmental abnormalities. Radiother Oncol. 2025;207:110848.
*Gallez B. Electron paramagnetic resonance (EPR) meets drug delivery and biomaterials: a magnetic love story. Drug Deliv Transl Res. 2025 (in press: https://doi.org/10.1007/s13346-025-01992-9).
Patents applications: 2
Summary of the findings
Identification of metabolic targets accounting for acquired radioresistance in human breast cancer models. Among the different adaptations that confer resistance to X-rays, cancer stem cells recently emerged as potential drivers of tumor recurrence and metastasis, making them a primary target for anticancer therapy. In a first unpublished study, we investigated how cancer stem cells and their metabolic plasticity could control radioresistance. For that aim, MDA-MB-231 human breast cancer cells were exposed to clinically relevant fractionated irradiation schemes of X-ray irradiation over time to obtain radioresistant (RR) cells, which was confirmed by colony formation assays. Although X-ray-irradiated cell lines show modified mitochondrial features, only RR cells expressed cancer stem-cell markers, including increased MYC gene and protein expression. Increased c-Myc expression and transcriptional activity was also observed in MCF7 RR cells that we produced using an alternative irradiation protocol. Among the various c-Myc inhibitors that we tested, KPT-65661 was found to be the most effective to decrease RR cell proliferation. Combining this inhibitor with X-ray irradiation decreased RR cell survival and tumor growth in vivo. However, it did not affect cancer cell sensitivity to proton radiotherapy. These finding were paralleled by a second unpublished study where we extended the metabolic characterization of wild-type and RR cells. Seahorse oximetry revealed that MDA-MB-231-RR cells were more oxidative than parental radiosensitive cells. Moreover, RNA sequencing allowed us to identify metabolic and stemness-related genes that correlated with patient outcome and could be responsible for acquired radioresistance. Independent RT-qPCR and western blotting confirmed the upregulation of 3 genes of interest in RR cells: glycolytic enzyme ALDOC, preprotein subunit of inhibin/activin INHBB, and transcription factor FOXA1. Using shRNAs and CRISPRi/CRISPRa approaches, we found that high INHBB expression accounted for radioresistance in RR cells. This protein can form activin or inhibin dimers,2 among which we have evidence at the transcriptional level (SMAD4 activation) that activin acts autocrinally on human breast cancer cells to render them radioresistant. We are currently testing activin receptor inhibitors as a new radiosensitizing strategy for both X-ray and proton radiotherapy.
Identification of new pharmacological strategies targeting oxidative phosphorylation to radiosensitize tumors. In a published study,3 we reported that MitoQ, a mitochondria-targeted agent,4 is a radiosensitizer that disrupts the electron flux at the electron transport chain (ETC) of several different cancer cell types. This was not a class effect, as other mitochondria-targeted antioxidants (MitoTEMPO and SKQ1) did not reduce mitochondrial oxygen consumption. Mechanistically, MitoQ blocked electron transfer to ETC Complex III, creating an oxygen sparing that radiosensitized human cancer cells in 2D, 3D and orthotopic models in mice. Importantly, tumors treated with MitoQ to prime fractionated radiotherapy did not regrow, and MitoQ further repressed irradiation-induced cancer cell migration and invasion.5 MitoQ already successfully passed Phase I clinical trials in humans with limited toxicity6 and is currently tested in Phase II and III clinical trials for other pathologies than cancer, making this drug a promising radiosensitizing agent for future clinical applications. We submitted a patent application for that aim, and further investigated mitochondria-targeted antioxidant mito-meformin7,8 and statins9 as additional radiosensitizers in models of human prostate cancer, with interesting radiosensitizing effects. We then investigated the contribution of mitochondrial reactive oxygen species (mtROS) to human breast cancer cell radiosensitivity using mitochondrial-targeted nitropyridine derivative Mito-NPH, designed to both induce mtROS production and inhibit ETC Complex I-dependent oxygen consumption. By dynamically monitoring mtROS generation and oxygen consumption rates (OCRs) in MDA-MB231 and MCF7 cells in vitro and in vivo, we were able to synchronize X-ray irradiation with either the peak of mtROS production or maximal tumor reoxygenation. Pretreatment with Mito-NPH consistently enhanced radiosensitivity under both normoxic and hypoxic conditions, with early mtROS induction driving apoptosis, ferroptosis, and cell cycle arrest associated to a perturbation of the autophagic flux. In vivo, X-ray irradiation delivered at the peak of mtROS production or maximal reoxygenation significantly delayed tumor growth, demonstrating that mtROS provide radiosensitizing effects independently of oxygen availability. Collectively, our studies identified MitoQ and Mito-NPH as pharmacological radiosensitizers, highlighting mitochondrial targeting as a promising strategy for future applications.
Identification and validation of a new technological approach to discriminate between global ROS and mtROS production in vivo. Because the precise site of ROS production plays an important role in cellular redox signaling and its (patho)physiological consequences, we developed EPR and dual nitroxide sensors composed of mitoTEMPO and carbamoyl-proxyl (3CP) to probe ROS production in mitochondrial and intracellular/extracellular compartments, respectively.10 For the proof-of-concept, the decay rates of the nitroxides were measured in 4T1 mouse breast tumor models, both in vitro and in vivo. To modulate the level of ROS either in the cytosol or in the mitochondria, cells and mice were treated with either glutathione synthesis inhibitor L-BSO or ETC Complex III inhibitor antimycin A. In mice, an increase in relative decay rate was observed for 3CP, but not for mitoTEMPO, 1 and 2 days after starting L-BSO treatment, while the opposite result was obtained after antimycin A treatment. These observations were consistent with results obtained on cells in vitro. Blood wash-out did not play a role in the decay of the nitroxide signal. In addition, overexpression of mitochondrial superoxide dismutase 2 (SOD2) allowed the assessment of the contribution of superoxide production to EPR signal decay. Overall, we identified a new protocol to noninvasively identify the site of ROS production in tumors in in vivo.
Identification that iron oxide nanoparticles radiosensitize cancer cells by weakening redox defenses. Still in the context of X-ray radiotherapy, we characterized the radiosensitizing effect of two iron oxide nanoparticle (IONP) formulations (7 nm carboxylated IONPs and PEG5000-IONPs) on A549 human lung carcinoma cells exposed to 225 kV of X-rays.11 Nanoparticles exhibited a radiosensitizing effect through inhibiting detoxification enzymes. In particular, a good correlation between the amplification effect at 2 Gy and the residual activity of thioredoxin reductase was observed, which was consistent with previous observations made for gold nanoparticles. Our study thus emphasized that IONP-induced radiosensitization does not result solely from physical phenomena, but also from biological events that we currently investigate.
Identification that ultra-high dose rate proton radiotherapy induces cellular senescence in nonmalignant cells. Because our metabolic studies did not identify a metabolic control of cancer cell resistance to proton therapy, we extended our investigation to nonmalignant cells. Irradiation can indeed damage healthy tissues around a tumor, with senescence induction as a notable side effect. In a recently published study,12 we compared the effects of X-rays to protons at conventional (2 Gy/min) and ultra-high (454 Gy/s) dose rates on primary normal human dermal fibroblasts. Ultra-high dose rate protons caused more pronounced cellular and nuclear morphological changes than irradiation with conventional protons or X-rays. All three types of irradiations induced an increase in the proportion of senescence-associated β-galactosidase-positive cells, an irreversible cell cycle arrest and an accumulation of unrepaired DNA damage, but none affected the senescence-associated secretory phenotype. This study calling for caution with use of ultra-high dose rate proton irradiation was paralleled by clinical efforts to optimize dose delivery13-17 and healthy tissue sparing18 during proton radiotherapy.
PhD theses
- BLACKMAN Marine. Director: Pierre Sonveaux (PhD thesis obtained 03/2023)
- BRUSTENGA Chiara. Director: Raphaël Frédérick, co-Director: Pierre Sonveaux (PhD thesis obtained 06/2024)
- d'HOSE Donatienne. Director: Bernard Gallez, co-Director: Bénédicte Jordan (PhD thesis obtained 11/2021)
- MATHIEU Barbara. Director: Bernard Gallez, co-Director: Pierre Sonveaux (PhD thesis obtained 12/2025)
- RONDEAU Justin. Director: Pierre Sonveaux (PhD thesis obtained 11/2024)
- ZAMPIERI Luca. Director: Pierre Sonveaux (PhD thesis obtained in 2022)
- COLAUZZI Ilaria. Director: Pierre Sonveaux (ongoing)
- HARDY Eleonore. Director: Anne-Catherine Heuskin, co-Director: Edmond Sterpin (ongoing)
- SAVOYEN Perrine. Director: Raphaël Frédérick, co-Director: Pierre Sonveaux (ongoing)
- VAN DE VELDE Justine. Director: Pierre Sonveaux (ongoing)
- VANDENSANDE Yasmine. Director: Bernard Gallez, co-Director: Pierre Sonveaux (ongoing)
Undergraduate theses
- CHATT Nadir. Director: Bernard Gallez (2022)
- BOUIDIDA Yasmine. Director: Pierre Sonveaux (2024)
- MELLOUL Samia. Director: Bernard Gallez (2024)
Peer-reviewed publications (those acknowledging ARC are marked with a *)
2021 (from 01/10)
Lesari S, Leclercq I, Joudiou N, Komuta M, Daumerie A, Ambroise J, Dili A, Feza-Bingi N, Xhema D, Bouzin C, Gallez B, Pisani F, Bonaccorsi-Riani E, Gianello P. Selective HIF stabilization alleviates hepatocellular steatosis and ballooning in a rodent model of 70% liver resection. Clin Sci (Lond). 2021;135:2285-2305.
*Zampieri LX, Sboarina M, Cacace A, Grasso D, Thabault L, Hamalin L, Vazeille T, Dumon E, Rossignol R, Frédérick R, Sonveaux E, Lefranc F, Sonveaux P. Olaparib is a mitochondrial Complex I inhibitor that kills temozolomide-resistant human glioblastoma cells. Int. J. Mol. Sci. 2021;22:11938.
Cappellesso F, Orban MP, Shirgaonkar N, Berardi E, Serneels J, Neveu MA, Di Molfetta D, Piccapane F, Caroppo R, Debellis L, Ostyn T, Joudiou N, Mignion L, Richiardone E, Jordan BF, Gallez B, Corbet C, Roskams T, DasGupta R, Tejpar S, Di Matteo M, Taverna D, Reshkin SJ, Topal B, Virga F, Mazzone M. Targeting the bicarbonate transporter SLC4A4 overcomes immunosuppression and immunotherapy resistance in pancreatic cancer. Nat Cancer. 2022;3:1464-1483.
Vander Veken L, Dechambre D, Sterpin E, Souris K, Van Ooteghem G, Aldo Lee J, Geets X. Incorporation of tumor motion directionality in margin recipe: the directional MidP strategy. Phys Med. 2021;91:43-53.
2022
*Thabault L, Brustenga C, Savoyen P, Van Gysel M, Wouters J, Sonveaux P, Frederick R, Liberelle M. Discovery of small molecules interacting at lactate dehydrogenases tetrameric interface using a biophysical screening cascade. Eur. J. Med. Chem. 2022;230:114102.
*Ippolito L, Sonveaux P, Chiarugi P. Unconventional roles of lactate along the tumor and immune landscape. Trends Endocrinol. Metabol. 2022;33(4):231-235.
Kemps H, Dessy C, Dumas L, Sonveaux P, Alders L, Van Broeckhoven J, Perez Font L, Lambrichts S, Foulquier S, Hendrix S, Brone B, Lemmens R, Bronckaers A. Extremely low frequency electromagnetic stimulation reduces ischemic stroke volume by improving central collateral blood flow. J. Cereb. Blood Flow Metab. 2022;42:979-996.
*Capeloa T, Krzystyniak J, d’Hose D, Canas Rodriguez A, Payen VL, Zampieri LX, Van de Velde J, Benyahia Z, Pranzini E, Vazeille T, Fransolet M, Bouzin C, Brusa D, Michiels C, Gallez B, Murphy MP, Porporato PE, Sonveaux P. MitoQ inhibits human breast cancer cell migration, invasion and clonogenicity. Cancers 2022;14:1516.
*Capeloa T, Krzystyniak J, Canas Rodriguez A, Payen VL, Zampieri LX, Pranzini E, Derouane F, Vazeille T, Bouzin C, Duhoux FP, Murphy MP, Porporato PE, Sonveaux P. MitoQ prevents human breast cancer recurrence and lung metastasis in mice. Cancers 2022;14:1488.
Macchi C, Moregola A, Greco MF, Svecla M, Bonacina F, Dhup S, Dadhich RK, Audano M, Sonveaux P, Mauro C, Mitro N, Ruscica M, Norata GD. Monocarboxylate transporter 1 deficiency impacts CD8 + T lymphocytes proliferation and recruitment to adipose tissue during obesity. iScience 2022;25(6):104435.
Weber DD, Aminzadeh-Gohari S, Thapa M, Redtenbacher AS, Catalano L, Capeloa T, Vazeille T, Emberger M, Felder TK, Feichtinger RG, Koelblinger P, Dallmann G, Sonveaux P, Lang R, Kofler B. Ketogenic diets slow melanoma growth in vivo regardless of tumor genetics and metabolic plasticity. Cancer Metab. 2022;10(1):12.
Blackman MCN, Capeloa T, Rondeau JD, Zampieri LX, Benyahia Z, Van de Velde J, Fransolet M, Daskalopoulos EP, Michiels C, Beauloye C, Sonveaux P. Mitochondrial protein Cox7b is a metabolic sensor driving brain-specific metastasis of human breast cancer cells. Cancers 2022;14:4371.
*D’Hose D, Mathieu B, Mignion L, Hardy M, Ouari O, Jordan BF, Sonveaux P, Gallez B. EPR Investigations to study the impact of mito-metformin on the mitochondrial function of prostate cancer cells. Molecules 2022;27(18):5872.
*D’Hose Donatienne, Mignion Lionel, Hamelin L, Sonveaux P, Jordan BF, Gallez B. Statins alleviate tumor hypoxia in prostate cancer models by decreasing oxygen consumption: an opportunity for radiosensitization? Biomolecules 2022;12(10):1418.
*Capeloa T, Van de Velde J, d’Hose D, Lipari SG, Derouane F, Hamelin L, Bedin M, Vazeille T, Duhoux FP, Murphy MP, Porporato PE, Gallez B, Sonveaux P. Inhibition of mitochondrial redox signaling with mitoQ prevents metastasis of human pancreatic cancer in mice. Cancers 2022;14(19):4918.
*Farah C, Neveu MA, Yelek C, Bouzin C, Gallez B, Baurain JF, Mignion L, Jordan BF. Combined HP 13C pyruvate and 13C-glucose fluxomic as a potential marker of response to targeted therapies in YUMM1.7 melanoma xenografts. Biomedicines 2022;10:717.
Gossuin Y, Gallez B. Editorial for "Phase I Randomized Trial of 17 O-Labeled Water: Safety and Feasibility Study of Indirect Proton MRI for the Evaluation of Cerebral Water Dynamics": old concepts, new applications. J Magn Reson Imaging. 2022;56:1883-1884.
Buyse C, Joudiou N, Warscotte A, Richiardone E, Minion L, Corbet C, Gallez B. Evaluation of syrosingopine, an MCT inhibitor, as potential modulator of tumor metabolism and extracellular acidification. Metabolites 2022 Jun 17;12(6):557.
d'Hose D, Gallez B. Measurement of mitochondrial (dys)function in cellular systems using electron Paramagnetic Resonance (EPR): Oxygen Consumption Rate and Superoxide Production. Methods Mol Biol 2022;2497:83-95.
Gallez B. The role of imaging biomarkers to guide pharmacological interventions targeting tumor hypoxia. Front Pharmacol. 2022;13:853568.
Saade G, Bogaerts E, Chiavassa S, Blain G, Delpon G, Evin M, Ghannam Y, Haddad F, Haustermans K, Koumeir C, Macaeva E, Maigne L, Mouchard Q, Servagent N, Sterpin E, Supiot S, Potiron V. Ultrahigh-dose-rate proton irradiation elicits reduced toxicity in zebrafish embryos. Adv Radiat Oncol. 2022;8:101124.
*Terwagne M, Nicolas E, Hespeels B, Herter L, Virgo J, Demazy C, Heuskin AC, Hallet B, Van Doninck K. DNA repair during nonreductional meiosis in the asexual rotifer Adineta vaga. Sci Adv. 2022;8:eadc8829.
Borderías-Villarroel E, Taasti V, Van Elmpt W, Teruel-Rivas S, Geets X, Sterpin E. Evaluation of the clinical value of automatic online dose restoration for adaptive proton therapy of head and neck cancer. Radiother Oncol. 2022;170:190-197.
Barragán-Montero A, Bibal A, Dastarac MH, Draguet C, Valdés G, Nguyen D, Willems S, Vandewinckele L, Holmström M, Löfman F, Souris K, Sterpin E, Lee JA. Towards a safe and efficient clinical implementation of machine learning in radiation oncology by exploring model interpretability, explainability and data-model dependency. Phys Med Biol. 2022;67:11TR01.
van der Heyden B, Heymans SV, Carlier B, Collado-Lara G, Sterpin E, D'hooge J. Deep learning for dose assessment in radiotherapy by the super-localization of vaporized nanodroplets in high frame rate ultrasound imaging. Phys Med Biol. 2022;67:115015.
Toumia Y, Pullia M, Domenici F, Facoetti A, Ferrarini M, Heymans SV, Carlier B, Van Den Abeele K, Sterpin E, D'hooge J, D'Agostino E, Paradossi G. Ultrasound-assisted carbon ion dosimetry and range measurement using injectable polymer-shelled phase-change nanodroplets: in vitro study. Sci Rep. 2022;12:8012.
Wuyckens S, Saint-Guillain M, Janssens G, Zhao L, Li X, Ding X, Sterpin E, Lee JA, Souris K. Treatment planning in arc proton therapy: Comparison of several optimization problem statements and their corresponding solvers. Comput Biol Med. 2022;148:105609.
Elhamiasl M, Salvo K, Poels K, Defraene G, Lambrecht M, Geets X, Sterpin E, Nuyts J. Low-dose CT allows for accurate proton therapy dose calculation and plan optimization. Phys Med Biol. 2022;67:195015.
Draguet C, Barragán-Montero AM, Vera MC, Thomas M, Populaire P, Defraene G, Haustermans K, Lee JA, Sterpin E. Automated clinical decision support system with deep learning dose prediction and NTCP models to evaluate treatment complications in patients with esophageal cancer. Radiother Oncol. 2022;176:101-107.
Wuyckens S, Zhao L, Saint-Guillain M, Janssens G, Sterpin E, Souris K, Ding X, Lee JA. Bi-criteria Pareto optimization to balance irradiation time and dosimetric objectives in proton arc therapy. Phys Med Biol. 2022;67(24):245017.
Badiu V, Souris K, Buti G, Villarroel EB, Lambrecht M, Sterpin E. Improved healthy tissue sparing in proton therapy of lung tumors using statistically sound robust optimization and evaluation. Phys Med. 2022;96:62-69.
2023
Buti G, Shusharina N, Ajdari A, Sterpin E, Bortfeld T. Exploring trade-offs in treatment planning for brain tumor cases with a probabilistic definition of the clinical target volume. Med Phys. 2023;50:410-423.
Ternad I, Penninckx S, Lecomte V, Vangijzegem T, Conrard L, Lucas S, Heuskin AC, Michiels C, Muller RN, Stanicki D, Laurent S. Advances in the mechanistic understanding of iron oxide nanoparticles' radiosensitizing properties. Nanomaterials (Basel). 2023;13:201.
*Gallez B, Mathieu B, Sonveaux P. About metformin and its action on the mitochondrial respiratory chain in prostate cancer. Transl Androl Urol 2023;13:909-914.
Borderias-Villarroel E, Fredriksson A, Cvilic S, Di Perri D, Longton E, Pierrard J, Geets X, Sterpin E. Dose mimicking based strategies for online adaptive proton therapy of head and neck cancer. Phys Med Biol. 2023;68(10):105002.
Borderias-Villarroel E, Huet Dastarac M, Barragán-Montero AM, Helander R, Holmstrom M, Geets X, Sterpin E. Machine learning-based automatic proton therapy planning: Impact of post-processing and dose-mimicking in plan robustness. Med Phys. 2023;50(7):4480-4490.
Deffet S, Hamaide V, Sterpin E. Definition of dose rate for FLASH pencil-beam scanning proton therapy: A comparative study. Med Phys. 2023;50(9):5784-5792.
2024
*Rondeau JD, Lipari S, Mathieu B, Beckers C, Van de Velde JA, Mignion L, Da Silva Morais M, Kreuzer M, Colauzzi I, Capeloa T, Pruschy M, Gallez B, Sonveaux P. Mitochondria-targeted antioxidant MitoQ radiosensitizes tumors by decreasing mitochondrial oxygen consumption. Cell Death Discov 2024;10(1):514.
*Rondeau JD, Van de Velde JA, Bouidida Y, Sonveaux P. Subclinical dose irradiation triggers human breast cancer migration via mitochondrial reactive oxygen species. Cancer Metab. 2024;12(1):20.
Scarmelotto A, Delprat V, Michiels C, Lucas S, Heuskin AC. The oxygen puzzle in FLASH radiotherapy: A comprehensive review and experimental outlook. Clin Transl Radiat Oncol. 2024 ;49:100860.
Daisne JF, Isebaert S, Geets X, Donnay L, Sterpin E. Protontherapy : principles, advantages, limitations, indications, perspectives...and some Belgian peculiarities. Rev Med Liege. 2024;79(S1):9-15.
Conq J, Joudiou N, Préat V, Gallez B. Exploring the impact of irradiation on glioblastoma blood-brain-barrier permeability: Insights from dynamic-contrast-enhanced-MRI and histological analysis. Biomedicines. 2024;12(5):1091.
2025
*Mathieu B, Rondeau JD, Mignion L, Sonveaux P, Gallez B. Noninvasive in vivo discrimination between mitochondrial ROS and global ROS production in solid tumors using EPR spectroscopy. Redox Biol 2025;87:103871.
*De Meester ME, Paulus H, Michiels C, Heuskin AC, Debacq-Chainiaux F. Senescence under the lens: X-ray vs. proton irradiation at conventional and ultra-high dose rate. Radiat Res. 2025;204(5):467-476.
Capeloa T, Van de Velde JA, Pranzini E, Ippolito L, Zampieri LX, Tardy M, Vazeille T, Provito A, Carrà G, Scalera A, Payen VL, Porporato PE, Sonveaux P. Mitochondrial ROS inhibition prevents doxorubicin-induced breast cancer cell migration and invasion. iScience 2025;28(8):113031.
Bogaerts E, Saade G, Macaeva E, Chiavassa S, Evin M, Haddad F, Isebaert S, Koumeir C, Mouchard Q, Potiron V, Servagent N, Supiot S, Sterpin E, Haustermans K. A comprehensive mechanistic study on the proton FLASH sparing effect in zebrafish embryos: From DNA damage to developmental abnormalities. Radiother Oncol. 2025;207:110848.
*Gallez B. Electron paramagnetic resonance (EPR) meets drug delivery and biomaterials: a magnetic love story. Drug Deliv Transl Res. 2025 (in press: https://doi.org/10.1007/s13346-025-01992-9).
Patents applications: 2