miRNAs as radio-response biomarkers for breast cancer stem cells Griñán Lisón, Carmen Olivares Urbano, María Auxiliadora Jiménez, Gema López Ruiz, Elena Val Muñoz, María Coral Del Morata-Tarifa, Cynthia Entrena, José Manuel González Ramírez, Amanda Rocío Boulaiz Tassi, Houria Zurita Herrera, Mercedes Núñez Torres, María Isabel Marchal Corrales, Juan Antonio Biomarkers Breast cancer miRNAs Radiotherapy Radiation In breast cancer (BC), the presence of cancer stem cells (CSCs) has been related to relapse, metastasis, and radioresistance. Radiotherapy (RT) is an extended BC treatment, but is not always effective. CSCs have several mechanisms of radioresistance in place, and some miRNAs are involved in the cellular response to ionizing radiation (IR). Here, we studied how IR affects the expression of miRNAs related to stemness in different molecular BC subtypes. Exposition of BC cells to radiation doses of 2, 4, or 6 Gy affected their phenotype, functional characteristics, pluripotency gene expression, and in vivo tumorigenic capacity. This held true for various molecular subtypes of BC cells (classified by ER, PR and HER-2 status), and for BC cells either plated in monolayer, or being in suspension as mammospheres. However, the effect of IR on the expression of eight stemness- and radioresistance-related miRNAs (miR-210, miR-10b, miR-182, miR-142, miR-221, miR-21, miR-93, miR-15b) varied, depending on cell line subpopulation and clinicopathological features of BC patients. Therefore, clinicopathological features and, potentially also, chemotherapy regimen should be both taken into consideration, for determining a potential miRNA signature by liquid biopsy in BC patients treated with RT. Personalized and precision RT dosage regimes could improve the prognosis, treatment, and survival of BC patients. 2020-03-03T08:49:22Z 2020-03-03T08:49:22Z 2019 info:eu-repo/semantics/article Griñán‐Lisón, C., Olivares‐Urbano, M. A., Jiménez, G., López‐Ruiz, E., del Val, C., Morata‐Tarifa, C., ... & Núñez, M. I. (2020). miRNAs as radio‐response biomarkers for breast cancer stem cells. Molecular Oncology. http://hdl.handle.net/10481/59942 10.1002/1878-0261.12635 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España FEBS Press