Alexander Helm1, Walter Tinganelli1, Palma Simoniello2, Fuki Kurosawa3, Claudia Fournier1, Takashi Shimokawa3, Marco Durante4. 1. GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany. 2. Department of Science and Technology, Parthenope University of Naples, Naples, Italy; Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Naples, Italy. 3. National Institute of Radiological Sciences, National Institutes of Quantum and Radiological Science and Technology, Chiba, Japan. 4. GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany; Technische Universität Darmstadt, Institut für Festkörperphysik, Darmstadt, Germany. Electronic address: m.durante@gsi.de.
Abstract
PURPOSE: The combination of radiation therapy and immunotherapy is recognized as a very promising strategy for metastatic cancer treatment. The purpose of this work is to compare the effectiveness of x-ray and high-energy carbon ion therapy in combination with checkpoint inhibitors in a murine model. METHODS AND MATERIALS: We used an osteosarcoma mouse model irradiated with either carbon ions or x-rays in combination with 2 immune checkpoint inhibitors (anti-PD-1 and anti-CTLA-4). LM8 osteosarcoma cells were injected in both hind limbs of female C3H/He mice 7 days before exposure to carbon ions or x-rays. In experimental groups receiving irradiation, only the tumor on the left limb was exposed, whereas the tumor on the right limb served as an abscopal mimic. Checkpoint inhibitors were injected intraperitoneally 1 day before exposure as well as concomitant to and after exposure. Tumor growth was measured regularly up to day 21 after exposure, when mice were sacrificed. Both tumors as well as lungs were extracted. RESULTS: A reduced growth of the abscopal tumor was most pronounced after the combined protocol of carbon ions and the immune checkpoint inhibitors administered sequentially. Radiation or checkpoint inhibitors alone were not sufficient to reduce the growth of the abscopal tumors. Carbon ions alone reduced the number of lung metastases more efficiently than x-rays, and in combination with immunotherapy both radiation types essentially suppressed the metastasis, with carbon ions being again more efficient. Investigation of the infiltration of immune cells in the abscopal tumors of animals treated with combination revealed an increase in CD8+ cells. CONCLUSIONS: Combination of checkpoint inhibitors with high-energy carbon ion radiation therapy can be an effective strategy for the treatment of advanced tumors.
PURPOSE: The combination of radiation therapy and immunotherapy is recognized as a very promising strategy for metastatic cancer treatment. The purpose of this work is to compare the effectiveness of x-ray and high-energy carbon ion therapy in combination with checkpoint inhibitors in a murine model. METHODS AND MATERIALS: We used an osteosarcomamouse model irradiated with either carbon ions or x-rays in combination with 2 immune checkpoint inhibitors (anti-PD-1 and anti-CTLA-4). LM8osteosarcoma cells were injected in both hind limbs of female C3H/He mice 7 days before exposure to carbon ions or x-rays. In experimental groups receiving irradiation, only the tumor on the left limb was exposed, whereas the tumor on the right limb served as an abscopal mimic. Checkpoint inhibitors were injected intraperitoneally 1 day before exposure as well as concomitant to and after exposure. Tumor growth was measured regularly up to day 21 after exposure, when mice were sacrificed. Both tumors as well as lungs were extracted. RESULTS: A reduced growth of the abscopal tumor was most pronounced after the combined protocol of carbon ions and the immune checkpoint inhibitors administered sequentially. Radiation or checkpoint inhibitors alone were not sufficient to reduce the growth of the abscopal tumors. Carbon ions alone reduced the number of lung metastases more efficiently than x-rays, and in combination with immunotherapy both radiation types essentially suppressed the metastasis, with carbon ions being again more efficient. Investigation of the infiltration of immune cells in the abscopal tumors of animals treated with combination revealed an increase in CD8+ cells. CONCLUSIONS: Combination of checkpoint inhibitors with high-energy carbon ion radiation therapy can be an effective strategy for the treatment of advanced tumors.
Authors: Daria Boscolo; Daria Kostyleva; Mohammad Javad Safari; Vasiliki Anagnostatou; Juha Äystö; Soumya Bagchi; Tim Binder; Georgios Dedes; Peter Dendooven; Timo Dickel; Vasyl Drozd; Bernhard Franczack; Hans Geissel; Chiara Gianoli; Christian Graeff; Tuomas Grahn; Florian Greiner; Emma Haettner; Roghieh Haghani; Muhsin N Harakeh; Felix Horst; Christine Hornung; Jan-Paul Hucka; Nasser Kalantar-Nayestanaki; Erika Kazantseva; Birgit Kindler; Ronja Knöbel; Natalia Kuzminchuk-Feuerstein; Bettina Lommel; Ivan Mukha; Chiara Nociforo; Shunki Ishikawa; Giulio Lovatti; Munetaka Nitta; Ikechi Ozoemelam; Stephane Pietri; Wolfgang R Plaß; Andrej Prochazka; Sivaji Purushothaman; Claire-Anne Reidel; Heidi Roesch; Fabio Schirru; Christoph Schuy; Olga Sokol; Timo Steinsberger; Yoshiki K Tanaka; Isao Tanihata; Peter Thirolf; Walter Tinganelli; Bernd Voss; Uli Weber; Helmut Weick; John S Winfield; Martin Winkler; Jianwei Zhao; Christoph Scheidenberger; Katia Parodi; Marco Durante Journal: Front Oncol Date: 2021-08-19 Impact factor: 5.738