Ionizing radiation: molecular mechanisms, biological effects, and therapeutic targets.

Radiation-induced injury remains a significant challenge in the radiotherapy of cancer patients. Ionizing radiation causes various cellular and molecular damages, leading to both acute and chronic organ dysfunction. Its impact extends beyond interrupting standard treatment protocols and adversely affects the quality of life. Therefore, understanding the mechanisms underlying radiation-induced injury and identifying effective treatment strategies are crucial. In this review, we summarize the recent advances in the molecular and cellular mechanisms of radiation-induced injury across various organs and systems, particularly in the lung, gastrointestinal system, brain, skin, and bone. We highlight the roles of oxidative stress, DNA damage response, mitochondrial dysfunction, and epigenetics in radiation pathology, and summarize the relevant signaling pathways and cellular responses involved in radiation damage. Additionally, we discuss the common symptoms, risk factors, and current diagnostic strategies of radiation-induced injuries. Furthermore, this article provides an in-depth review of effective clinical treatments, elucidates their mechanisms of action, and highlights emerging therapeutic approaches, such as stem cell therapy, nanomedicine, and exosome-based interventions, in clinical practice. Despite significant advances in understanding radiation-induced injury, challenges remain in translating molecular insights into effective therapies. The review concludes with a call for integrated, precision medicine-based approaches to better manage radiation-induced injuries and improve patient outcomes.