Enhancing the Bystander and Abscopal Effects to Improve Radiotherapy Outcomes de Araújo Farias, Virgínea Tovar Gálvez, María Isabel García Morales, María Del Rosario O´Valle, Francisco Expósito Hernández, José Oliver, Francisco Javier Ruiz De Almodóvar Rivera, José Mariano experimental radiotherapy cell loss mesenchymal cells In this paper, we summarize published articles and experiences related to the attempt to improve radiotherapy outcomes and, thus, to personalize the radiation treatment according to the individual characteristics of each patient. The evolution of ideas and the study of successively published data have led us to envisage new biophysical models for the interpretation of tumor and healthy normal tissue response to radiation. In the development of the model, we have shown that when mesenchymal stem cells (MSCs) and radiotherapy are administered simultaneously in experimental radiotherapy on xenotumors implanted in a murine model, the results of the treatment show the existence of a synergic mechanism that is able to enhance the local and systemic actions of the radiation both on the treated tumor and on its possible metastasis. We are convinced that, due to the physical hallmarks that characterize the neoplastic tissues, the physical–chemical tropism of MSCs, and the widespread functions of macromolecules, proteins, and exosomes released from activated MSCs, the combination of radiotherapy plus MSCs used intratumorally has the effect of counteracting the pro-tumorigenic and pro-metastatic signals that contribute to the growth, spread, and resistance of the tumor cells. Therefore, we have concluded that MSCs are appropriate for therapeutic use in a clinical trial for rectal cancer combined with radiotherapy, which we are going to start in the near future. 2024-11-25T12:27:12Z 2024-11-25T12:27:12Z 2020-01-08 journal article de Araújo Farias, V. et. al. Front. Oncol. 9:1381. [https://doi.org/10.3389/fonc.2019.01381] https://hdl.handle.net/10481/97339 10.3389/fonc.2019.01381 eng http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional Frontiers Media