Salvarredi Leonardo, Agüero Héctor, Millan María Elisa, Marra María Fernanda, Callegari Eduardo, Castro Claudia, Lopez Luis
Nuclear Medicine School Foundation, Mendoza, Argentina.
National Commission of Atomic Energy (CNEA), Mendoza, Argentina.
Int J Radiat Biol. 2025;101(7):710-719. doi: 10.1080/09553002.2025.2505525. Epub 2025 May 21.
Senescence is a key cellular response to ionizing radiation. Senescent cells experience irreversible growth arrest while remaining metabolically active and secrete a distinct set of proteins, collectively referred to as the senescence-associated secretory phenotype (SASP). These secreted factors influence neighboring non-irradiated cells through a mechanism known as the bystander effect. This study aimed to investigate and characterize the bystander effect in a melanoma cell model.
Murine melanoma B16F0 cells were exposed to X-irradiation (10 Gy), and senescence was induced 3 days later. Conditioned media from the senescent cells was collected and used to culture non-irradiated B16F0 cells. Proliferation, viability, clonogenic capacity, DNA damage foci formation, apoptosis, and senescence were assessed. The composition of the senescence-associated secretory phenotype was analyzed using mass spectrometry and bioinformatics tools.
Conditioned media from senescent cells induced by radiation reduced growth and promoted senescence in tumor cell cultures not exposed to ionizing radiation. Mass spectrometry analysis revealed greater protein diversity and abundance in conditioned media from senescent cells compared to that from non-irradiated cells. Additionally, conditioned media from senescent cells contained higher concentrations of proteins related to immune response, cellular aging, and responses to oxidative stress.
Cells undergoing radiation-induced senescence promote bystander senescence by secreting soluble factors involved in the induction and maintenance of senescence.
衰老作为细胞对电离辐射的关键反应，衰老细胞虽经历不可逆的生长停滞，但仍保持代谢活性，并分泌一组独特的蛋白质，统称为衰老相关分泌表型（SASP）。这些分泌因子通过一种被称为旁观者效应的机制影响邻近未受辐射的细胞。本研究旨在探究并表征黑色素瘤细胞模型中的旁观者效应。
将小鼠黑色素瘤B16F0细胞暴露于X射线辐射（10 Gy），3天后诱导其衰老。收集衰老细胞的条件培养基，用于培养未受辐射的B16F0细胞。评估细胞增殖、活力、克隆形成能力、DNA损伤灶形成、凋亡和衰老情况。使用质谱和生物信息学工具分析衰老相关分泌表型的组成。
辐射诱导的衰老细胞的条件培养基可降低未暴露于电离辐射的肿瘤细胞培养物的生长并促进其衰老。质谱分析显示，与未受辐射细胞相比，衰老细胞的条件培养基中蛋白质多样性更高且丰度更大。此外，衰老细胞的条件培养基中含有更高浓度的与免疫反应、细胞衰老和氧化应激反应相关的蛋白质。
经历辐射诱导衰老的细胞通过分泌参与衰老诱导和维持的可溶性因子来促进旁观者衰老。
