DNA Repair, radiations and innovative cancer therapies

Team Publications

Year of publication 2021

Alexandre Leduc, Samia Chaouni, Frédéric Pouzoulet, Ludovic De Marzi, Frédérique Megnin-Chanet, Erwan Corre, Dinu Stefan, Jean-Louis Habrand, François Sichel, Carine Laurent (2021 Mar 13)

Differential normal skin transcriptomic response in total body irradiated mice exposed to scattered versus scanned proton beams.

Scientific reports : 11 : 5876 : DOI : 10.1038/s41598-021-85394-0 Learn more

Proton therapy allows to avoid excess radiation dose on normal tissues. However, there are some limitations. Indeed, passive delivery of proton beams results in an increase in the lateral dose upstream of the tumor and active scanning leads to strong differences in dose delivery. This study aims to assess possible differences in the transcriptomic response of skin in C57BL/6 mice after TBI irradiation by active or passive proton beams at the dose of 6 Gy compared to unirradiated mice. In that purpose, total RNA was extracted from skin samples 3 months after irradiation and RNA-Seq was performed. Results showed that active and passive delivery lead to completely different transcription profiles. Indeed, 140 and 167 genes were differentially expressed after active and passive scanning compared to unirradiated, respectively, with only one common gene corresponding to RIKEN cDNA 9930021J03. Moreover, protein-protein interactions performed by STRING analysis showed that 31 and 25 genes are functionally related after active and passive delivery, respectively, with no common gene between both types of proton delivery. Analysis showed that active scanning led to the regulation of genes involved in skin development which was not the case with passive delivery. Moreover, 14 ncRNA were differentially regulated after active scanning against none for passive delivery. Active scanning led to 49 potential mRNA-ncRNA pairs with one ncRNA mainly involved, Gm44383 which is a miRNA. The 43 genes potentially regulated by the miRNA Gm44393 confirmed an important role of active scanning on skin keratin pathway. Our results demonstrated that there are differences in skin gene expression still 3 months after proton irradiation versus unirradiated mouse skin. And strong differences do exist in late skin gene expression between scattered or scanned proton beams. Further investigations are strongly needed to understand this discrepancy and to improve treatments by proton therapy.

Fold up

Year of publication 2020

Andreas Schüller, Sophie Heinrich, Charles Fouillade, Anna Subiel, Ludovic De Marzi, Francesco Romano, Peter Peier, Maria Trachsel, Celeste Fleta, Rafael Kranzer, Marco Caresana, Samuel Salvador, Simon Busold, Andreas Schönfeld, Malcolm McEwen, Faustino Gomez, Jaroslav Solc, Claude Bailat, Vladimir Linhart, Jan Jakubek, Jörg Pawelke, Marco Borghesi, Ralf-Peter Kapsch, Adrian Knyziak, Alberto Boso, Veronika Olsovcova, Christian Kottler, Daniela Poppinga, Iva Ambrozova, Claus-Stefan Schmitzer, Severine Rossomme, Marie-Catherine Vozenin (2020 Nov 12)

The European Joint Research Project UHDpulse – Metrology for advanced radiotherapy using particle beams with ultra-high pulse dose rates.

Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB) : 134-150 : DOI : S1120-1797(20)30236-2 Learn more

UHDpulse – Metrology for advanced radiotherapy using particle beams with ultra-high pulse dose rates is a recently started European Joint Research Project with the aim to develop and improve dosimetry standards for FLASH radiotherapy, very high energy electron (VHEE) radiotherapy and laser-driven medical accelerators. This paper gives a short overview about the current state of developments of radiotherapy with FLASH electrons and protons, very high energy electrons as well as laser-driven particles and the related challenges in dosimetry due to the ultra-high dose rate during the short radiation pulses. We summarize the objectives and plans of the UHDpulse project and present the 16 participating partners.

Fold up
Sofia Ferreira, Chloe Foray, Alberto Gatto, Magalie Larcher, Sophie Heinrich, Mihaela Lupu, Joel Mispelter, François D Boussin, Célio Pouponnot, Marie Dutreix (2020 Sep 9)

AsiDNA Is a Radiosensitizer with no Added Toxicity in Medulloblastoma Pediatric Models.

Clinical cancer research : an official journal of the American Association for Cancer Research : 5735-5746 : DOI : 10.1158/1078-0432.CCR-20-1729 Learn more

Medulloblastoma is an important cause of mortality and morbidity in pediatric oncology. Here, we investigated whether the DNA repair inhibitor, AsiDNA, could help address a significant unmet clinical need in medulloblastoma care, by improving radiotherapy efficacy without increasing radiation-associated toxicity.

Fold up
Pierre-Marie Girard, Nathalie Berthault, Maria Kozlac, Sofia Ferreira, Wael Jdey, Srividya Bhaskara, Sergey Alekseev, Frederic Thomas, Marie Dutreix (2020 Aug 22)

Evolution of tumor cells during AsiDNA treatment results in energy exhaustion, decrease in responsiveness to signal, and higher sensitivity to the drug.

Evolutionary applications : 1673-1680 : DOI : 10.1111/eva.12949 Learn more

It is increasingly suggested that ecological and evolutionary sciences could inspire novel therapies against cancer but medical evidence of this remains scarce at the moment. The Achilles heel of conventional and targeted anticancer treatments is intrinsic or acquired resistance following Darwinian selection; that is, treatment toxicity places the surviving cells under intense evolutionary selective pressure to develop resistance. Here, we review a set of data that demonstrate that Darwinian principles derived from the “smoke detector” principle can instead drive the evolution of malignant cells toward a different trajectory. Specifically, long-term exposure of cancer cells to a strong alarm signal, generated by the DNA repair inhibitor AsiDNA, induces a stable new state characterized by a down-regulation of the targeted pathways and does not generate resistant clones. This property is due to the original mechanism of action of AsiDNA, which acts by overactivating a “false” signaling of DNA damage through DNA-PK and PARP enzymes, and is not observed with classical DNA repair inhibitors such as the PARP inhibitors. Long-term treatment with AsiDNA induces a new “alarm down” state in the tumor cells with decrease in NAD level and reactiveness to it. These results suggest that agonist drugs such as AsiDNA could promote a state-dependent tumor cell evolution by lowering their ability to respond to high “danger” signal. This analysis provides a compelling argument that evolutionary ecology could help drug design development in overcoming fundamental limitation of novel therapies against cancer due to the modification of the targeted tumor cell population during treatment.

Fold up
Rudi Labarbe, Lucian Hotoiu, Julie Barbier, Vincent Favaudon (2020 Jun 15)

A physicochemical model of reaction kinetics supports peroxyl radical recombination as the main determinant of the FLASH effect.

Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology : 303-310 : DOI : S0167-8140(20)30308-X Learn more

FLASH radiotherapy, a technique based on delivering large doses in a single fraction at the micro/millisecond timescale, spares normal tissues from late radiation-induced toxicity, in an oxygen-dependent process, whilst keeping full anti-tumor efficiency. We present a theoretical model taking into account the kinetics of formation and decay of reactive oxygen species, in particular of organic peroxyl radicals ROO formed by addition of O to primary carbon-centred radicals R and known to play a major role at the origin radio-induced complications.

Fold up
Jan Schuemann, Alexander F Bagley, Ross Berbeco, Kyle Bromma, Karl T Butterworth, Hilary L Byrne, B Devika Chithrani, Sang Hyun Cho, Jason R Cook, Vincent Favaudon, Yaser H Gholami, Elisabetta Gargioni, James F Hainfeld, Félicien Hespeels, Anne-Catherine Heuskin, Udoka M Ibeh, Zdenka Kuncic, Sijumon Kunjachan, Sandrine Lacombe, Stéphane Lucas, François Lux, Stephen McMahon, Dmitry Nevozhay, Wilfred Ngwa, J Donald Payne, Sébastien Penninckx, Erika Porcel, Kevin M Prise, Hans Rabus, Sharif M Ridwan, Benedikt Rudek, Léon Sanche, Bijay Singh, Henry M Smilowitz, Konstantin V Sokolov, Srinivas Sridhar, Yaroslav Stanishevskiy, Wonmo Sung, Olivier Tillement, Needa Virani, Wassana Yantasee, Sunil Krishnan (2020 May 8)

Roadmap for metal nanoparticles in radiation therapy: current status, translational challenges, and future directions.

Physics in medicine and biology : 21RM02 : DOI : 10.1088/1361-6560/ab9159 Learn more

This roadmap outlines the potential roles of metallic nanoparticles (MNPs) in the field of radiation therapy. MNPs made up of a wide range of materials (from Titanium, Z = 22, to Bismuth, Z = 83) and a similarly wide spectrum of potential clinical applications, including diagnostic, therapeutic (radiation dose enhancers, hyperthermia inducers, drug delivery vehicles, vaccine adjuvants, photosensitizers, enhancers of immunotherapy) and theranostic (combining both diagnostic and therapeutic), are being fabricated and evaluated. This roadmap covers contributions from experts in these topics summarizing their view of the current status and challenges, as well as expected advancements in technology to address these challenges.

Fold up
Debora Grasso, Hyllana C D Medeiros, Luca X Zampieri, Vanesa Bol, Pierre Danhier, Marike W van Gisbergen, Caroline Bouzin, Davide Brusa, Vincent Grégoire, Hubert Smeets, Alphons P M Stassen, Ludwig J Dubois, Philippe Lambin, Marie Dutreix, Pierre Sonveaux (2020 Apr 2)

Fitter Mitochondria Are Associated With Radioresistance in Human Head and Neck SQD9 Cancer Cells.

Frontiers in pharmacology : 263 : DOI : 10.3389/fphar.2020.00263 Learn more

The clinical management of head and neck squamous cell carcinoma (HNSCC) commonly involves chemoradiotherapy, but recurrences often occur that are associated with radioresistance. Using human SQD9 laryngeal squamous cell carcinoma cancer cells as a model, we aimed to identify metabolic changes associated with acquired radioresistance. In a top-down approach, matched radiosensitive and radioresistant SQD9 cells were generated and metabolically compared, focusing on glycolysis, oxidative phosphorylation (OXPHOS) and ROS production. The cell cycle, clonogenicity, tumor growth in mice and DNA damage-repair were assessed. Mitochondrial DNA (mtDNA) was sequenced. In a bottom-up approach, matched glycolytic and oxidative SQD9 cells were generated using FACS-sorting, and tested for their radiosensitivity/radioresistance. We found that acquired radioresistance is associated with a shift from a glycolytic to a more oxidative metabolism in SQD9 cells. The opposite was also true, as the most oxidative fraction isolated from SQD9 wild-type cells was also more radioresistant than the most glycolytic fraction. However, neither reduced hexokinase expression nor OXPHOS were directly responsible for the radioresistant phenotype. Radiosensitive and radioresistant cells had similar proliferation rates and were equally efficient for ATP production. They were equally sensitive to redox stress and had similar DNA damage repair, but radioresistant cells had an increased number of mitochondria and a higher mtDNA content. Thus, an oxidative switch is associated with but is not responsible for acquired radioresistance in human SQD9 cells. In radioresistant cells, more abundant and fitter mitochondria could help to preserve mitochondrial functions upon irradiation.

Fold up

Year of publication 2019

Charles Fouillade, Sandra Curras-Alonso, Lorena Giuranno, Eddy Quelennec, Sophie Heinrich, Sarah Bonnet-Boissinot, Arnaud Beddok, Sophie Leboucher, Hamza Umut Karakurt, Mylène Bohec, Sylvain Baulande, Marc Vooijs, Pierre Verrelle, Marie Dutreix, Arturo Londoño-Vallejo, Vincent Favaudon (2019 Dec 5)

FLASH Irradiation Spares Lung Progenitor Cells and Limits the Incidence of Radio-induced Senescence.

Clinical cancer research : an official journal of the American Association for Cancer Research : DOI : 10.1158/1078-0432.CCR-19-1440 Learn more

One of the main limitations to anticancer radiotherapy lies in irreversible damage to healthy tissues located within the radiation field. “FLASH” irradiation at very high dose-rate is a new treatment modality that has been reported to specifically spare normal tissue from late radiation-induced toxicity in animal models and therefore could be a promising strategy to reduce treatment toxicity.

Fold up
Nirmitha I Herath, Nathalie Berthault, Sylvain Thierry, Wael Jdey, Marie-Christine Lienafa, Françoise Bono, Patricia Noguiez-Hellin, Jian-Sheng Sun, Marie Dutreix (2019 Nov 30)

Preclinical Studies Comparing Efficacy and Toxicity of DNA Repair Inhibitors, Olaparib, and AsiDNA, in the Treatment of Carboplatin-Resistant Tumors.

Frontiers in oncology : 1097 : DOI : 10.3389/fonc.2019.01097 Learn more

Carboplatin is used to treat many cancers, but occurrence of drug resistance and its high toxicity remain a clinical hurdle limiting its efficacy. We compared the efficacy and toxicity of DNA repair inhibitors olaparib or AsiDNA administered alone or in combination with carboplatin. Olaparib acts by inhibiting PARP-dependent repair pathways whereas AsiDNA inhibits double-strand break repair by preventing recruitment of enzymes involved in homologous recombination and non-homologous end joining. Mice with MDA-MB-231 tumors were treated with carboplatin or/and olaparib or AsiDNA for three treatment cycles. Survival and tumor growth were monitored. Toxicities of treatments were assayed in C57BL/6 immunocompetent mice. Circulating blood hematocrits, bone marrow cells, and organs were analyzed 10 and 21 days after end of treatment using flow cytometry and microscopy analysis. Resistance occurrence was monitored after cycles of treatments with combination of AsiDNA and carboplatin in independent BC227 cell cultures. Olaparib or AsiDNA monotherapies decreased tumor growth and increased mean survival of grafted animals. The combination with carboplatin further increased survival. Carboplatin toxicity resulted in a decrease of most blood cells, platelets, thymus, and spleen lymphocytes. Olaparib or AsiDNA monotherapies had no toxicity, and their combination with carboplatin did not increase toxicity in the bone marrow or thrombocytopenia. All animals receiving carboplatin combined with olaparib developed high liver toxicity with acute hepatitis at 21 days. , carboplatin resistance occurs after three cycles of treatment in all six tested cultures, whereas only one became resistant (1/5) after five cycles when carboplatin was associated to low doses of AsiDNA. All selected carboplatin-resistant clones retain sensitivity to AsiDNA. DNA repair inhibitor treatments are efficient in the platinum resistant model, MDA-MB-231. The combination with carboplatin improves survival. The association of carboplatin with olaparib is associated with high liver toxicity, which is not observed with AsiDNA. AsiDNA could delay resistance to carboplatin without increasing its toxicity.

Fold up
Julian Biau, Emmanuel Chautard, Pierre Verrelle, Marie Dutreix (2019 Oct 26)

Altering DNA Repair to Improve Radiation Therapy: Specific and Multiple Pathway Targeting.

Frontiers in oncology : 1009 : DOI : 10.3389/fonc.2019.01009 Learn more

Radiation therapy (RT) is widely used in cancer care strategies. Its effectiveness relies mainly on its ability to cause lethal damage to the DNA of cancer cells. However, some cancers have shown to be particularly radioresistant partly because of efficient and redundant DNA repair capacities. Therefore, RT efficacy might be enhanced by using drugs that can disrupt cancer cells’ DNA repair machinery. Here we review the recent advances in the development of novel inhibitors of DNA repair pathways in combination with RT. A large number of these compounds are the subject of preclinical/clinical studies and target key enzymes involved in one or more DNA repair pathways. A totally different strategy consists of mimicking DNA double-strand breaks via small interfering DNA (siDNA) to bait the whole DNA repair machinery, leading to its global inhibition.

Fold up
Wael Jdey, Maria Kozlak, Sergey Alekseev, Sylvain Thierry, Pauline Lascaux, Pierre-Marie Girard, Françoise Bono, Marie Dutreix (2019 Jul 31)

AsiDNA Treatment Induces Cumulative Antitumor Efficacy with a Low Probability of Acquired Resistance.

Neoplasia (New York, N.Y.) : 863-871 : DOI : S1476-5586(19)30213-1 Learn more

The Achilles heel of anticancer treatments is intrinsic or acquired resistance. Among many targeted therapies, the DNA repair inhibitors show limited efficacy due to rapid emergence of resistance. We examined evolution of cancer cells and tumors treated with AsiDNA, a new DNA repair inhibitor targeting all DNA break repair pathways. Effects of AsiDNA or Olaparib were analyzed in various cell lines. Frequency of AsiDNA- and olaparib-resistant clones was measured after 2 weeks of continuous treatment in KBM7 haploid cells. Cell survivals were also measured after one to six cycles of 1-week treatment and 1-week recovery in MDA-MB-231 and NCI-H446. Transcriptomes of cell populations recovering from cyclic treatments or mock treatment were compared. MDA-MB-231 xenografted models were treated with three cycles of AsiDNA to monitor the effects of treatment on tumor growth and transcriptional modifications. No resistant clones were selected after AsiDNA treatment (frequency < 3×10) in treatment conditions that generate resistance to olaparib at a frequency of 7.2×10 resistant clones per treated cell. Cyclic treatments promote cumulative sensitivity characterized by a higher mortality of cells having undergone previous treatment cycles. This sensitization was stable, and transcriptome analysis revealed a major gene downregulation with a specific overrepresentation of genes coding for targets of DNA-PK. Such changes were also detected in tumor models which showed impaired growth after cycles of AsiDNA treatment.

Fold up
Julian Biau, Emmanuel Chautard, Nathalie Berthault, Leanne de Koning, Frank Court, Bruno Pereira, Pierre Verrelle, Marie Dutreix (2019 Jul 6)

Combining the DNA Repair Inhibitor Dbait With Radiotherapy for the Treatment of High Grade Glioma: Efficacy and Protein Biomarkers of Resistance in Preclinical Models.

Frontiers in oncology : 549 : DOI : 10.3389/fonc.2019.00549 Learn more

High grade glioma relapses occur often within the irradiated volume mostly due to a high resistance to radiation therapy (RT). Dbait (which stands for DNA strand break bait) molecules mimic DSBs and trap DNA repair proteins, thereby inhibiting repair of DNA damage induced by RT. Here we evaluate the potential of Dbait to sensitize high grade glioma to RT. First, we demonstrated the radiosensitizer properties of Dbait in 6/9 tested cell lines. Then, we performed animal studies using six cell derived xenograft and five patient derived xenograft models, to show the clinical potential and applicability of combined Dbait+RT treatment for human high grade glioma. Using a RPPA approach, we showed that Phospho-H2AX/H2AX and Phospho-NBS1/NBS1 were predictive of Dbait efficacy in xenograft models. Our results provide the preclinical proof of concept that combining RT with Dbait inhibition of DNA repair could be of benefit to patients with high grade glioma.

Fold up

Year of publication 2018

Annalisa Patriarca, Charles Fouillade, Michel Auger, Frédéric Martin, Frédéric Pouzoulet, Catherine Nauraye, Sophie Heinrich, Vincent Favaudon, Samuel Meyroneinc, Rémi Dendale, Alejandro Mazal, Philip Poortmans, Pierre Verrelle, Ludovic De Marzi (2018 Nov 1)

Experimental set-up for FLASH proton irradiation of small animals using a clinical system

International Journal of Radiation Oncology • Biology • Physics : 102 : 619-626 : DOI : 10.1016/j.ijrobp.2018.06.403 Learn more


Recent in vivo investigations have shown that short pulses (FLASH) of electrons are less harmful to healthy tissues, but just as efficient as conventional dose-rate radiation to inhibit tumor growth. In view of the potential clinical value of FLASH and the availability of modern proton therapy infrastructures to achieve this goal, we herein describe a series of technological developments required to investigate the biology of FLASH irradiation, using a commercially available clinical proton therapy system.

Methods and materials

Numerical simulations and experimental dosimetric characterization of a modified clinical proton beamline, upstream from the isocenter were performed with Monte Carlo toolkit and different detectors. A single scattering system was optimized together with a ridge filter and a high current monitoring system. In addition, a submillimetric set-up protocol based on image-guidance using a digital camera and an animal positioning system was also developed.


The dosimetric properties of the resulting beam and monitoring system were characterized: linearity with dose rate and homogeneity for a 12×12 mm2 field size were assessed. Dose rates exceeding 40 Gy/s at energies between 138 and 198 MeV were obtained, enabling uniform irradiation for radiobiology investigations on small animals in a modified clinical proton beam line.


This approach will enable us to conduct FLASH proton therapy experiments on small animals, specifically for mouse lung irradiation. Dose rates exceeding 40 Gy/s were achieved, which was not possible with the conventional clinical mode of the existing beamline.

Fold up
Marie-Catherine Vozenin, Pauline De Fornel, Kristoffer Petersson, Vincent Favaudon, Maud Jaccard, Jean-François Germond, Benoit Petit, Marco Burki, Gisèle Ferrand, David Patin, Hanan Bouchaab, Mahmut Ozsahin, François Bochud, Claude Bailat, Patrick Devauchelle, Jean Bourhis (2018 Jun 8)

The Advantage of FLASH Radiotherapy Confirmed in Mini-pig and Cat-cancer Patients.

Clinical cancer research : an official journal of the American Association for Cancer Research : 35-42 : DOI : 10.1158/1078-0432.CCR-17-3375 Learn more

Previous studies using FLASH radiotherapy (RT) in mice showed a marked increase of the differential effect between normal tissue and tumors. To stimulate clinical transfer, we evaluated whether this effect could also occur in higher mammals.

Fold up

Year of publication 2017

Sylvain Thierry, Wael Jdey, Solana Alculumbre, Vassili Soumelis, Patricia Noguiez-Hellin, Marie Dutreix (2017 Sep 27)

The DNA repair inhibitor Dbait is specific for malignant hematologic cells in blood.

Molecular cancer therapeutics : DOI : molcanther.0405.2017 Learn more

Hematologic malignancies are rare cancers that develop refractory disease upon patient relapse, resulting in decreased life expectancy and quality of life. DNA repair inhibitors are promising strategy to treat cancer but are limited by their hematologic toxicity in combination with conventional chemotherapies. Dbait are large molecules targeting the signaling of DNA damage and inhibiting all the double-strand DNA break pathways. Dbait have been shown to sensitize resistant solid tumors to radiotherapy and Platinium salts. Here, we analyze the efficacy and lack of toxicity of AsiDNA, a cholesterol form of Dbait, in hematologic malignancies. We show that AsiDNA, enters cells via LDL receptors and activates its molecular target, the DNA dependent protein kinase (DNA-PKcs) in 10 lymphoma and leukemia cell lines (Jurkat-E6.1, MT-4, MOLT-4, 174xCEM.T2, Sup-T1, HuT-78, Raji, IM-9, THP-1 and U-937) and in normal primary human PBMCs, resting or activated T-cells, and CD34+ progenitors. The treatment with AsiDNA induced necrotic and mitotic cell death in most cancer cell lines and had no effect on blood or bone marrow cells, including immune activation, proliferation or differentiation. Sensitivity to AsiDNA was independent of p53 status. Survival to combined treatment with conventional therapies (etoposide, cyclophosphamides, vincristine, or radiotherapy) was analyzed by isobolograms and combination index. AsiDNA synergized with all treatments, except vincristine, without increasing their toxicity to normal blood cells. AsiDNA is a novel, potent, and wide range drug with the potential to specifically increase DNA damaging treatment toxicity in tumor without adding toxicity in normal hematologic cells or inducing immune dysregulation.

Fold up