Cellular mechanisms underlying tumor and normal tissue radiosensitivity

Chaves-Campos, F A; Ortiz-Morales, F; Vásquez-Cerdas, M

Abstract:

This review aims to provide an overview of the main cellular mechanisms that in昀氀uence the response of healthy and tumor tissues to radiation and, thus, their radiosensitivity. Knowledge of the biological mechanisms that de昀椀ne individual radiosensitivity is the initial path for establishing assays aimed at predicting responses to treatment and is essential to achieve the application of personalized medicine in RT procedures. In this sense, the interest in studying radiosensitivity in the clinical setting is the determination of 1) the individual risk of developing adverse effects to IR treatment (clinical or normal tissue radiosensitivity) and 2) the possible therapeutic bene昀椀t of IR (tumor radiosensitivity). The authors conducted an extensive review of articles and resources on radiation biology and cellular mechanisms that affect the response of both normal and cancerous tissues to ionizing radiation (IR) treatment. The review primarily focuses on materials published from 2000 to March 2023 while incorporating select older articles to enrich the discussion. To gather these articles from popular electronic databases such as PubMed, ScienceDirect, Google Scholar, and Cochrane, the authors utilized a search strategy that employed Boolean “AND” and “OR” logic. The different combinations of keywords searched included the following terms: “radiosensitivity”, “cellular”, “radiation sensitivity”, “radioresistance”, “ionizing radiation”, “radiotherapy”, “biological effects”, “tumor”, “normal tissues”, “cellular mechanisms”, “oxidative stress”, “DNA repair”, “immune response”, “cell death”, “radio induced effects”. Conclusions: Radiation therapy (RT) is one of the primary treatment modalities in oncology, along with surgery, chemotherapy, and immunotherapy. RT delivers a precise and suf昀椀cient dose to tumor tissues, inducing cell death. However, individual response to IR exposure varies based on the type of therapy used (i.e., external RT, radiosurgery, brachytherapy, among others) and the intrinsic heterogeneity between tumor types and subtypes. In addition, variants in genes controlling the cellular response to DNA damage, oxidative stress, cell cycle control, cell death, and the immune response would lead to a spectrum of radiosensitivity. Understanding how radiation impacts normal and tumor cells at a cellular level is essential to develop effective treatment options that account for biological differences among individuals. While many people experience moderate sensitivity to radiation therapy regarding side effects and tumor response, there may be variations in sensitivity. Therefore, acquiring this knowledge is essential to achieve the best clinical outcomes.

Year:

2024

Type of Publication:

Article

Journal:

J Health Med Sci

Volume:

10

Number:

1

Pages:

37-49