Abstract
Radiotherapy is a front treatment for many types of cancer. One of its advantages is to target specific tumor site, however under some condition, there are still risks to induce complications in the surrounding normal tissues. The mechanisms of radiation-induced normal tissue damage are complicated and involve different tissue components such as epithelial cell, stromal cells, inflammatory and immune responses. Our previous studies have found induction of pro-inflammatory are involved in early phases of normal tissue responses to radiation. The purpose of this study is to extend our previous observation and compare the short-term induction of pro-inflammatory cytokines in different organs following whole body irradiation. We used C57BL/6J mice as an animal model and analyzed gene expression of pro-inflammatory cytokine in eight organs (brain, lung, liver, kidney, spleen, intestine, bladder and prostate) at different time following whole body irradiation. LPS was used as a positive control for the expression pattern of cytokine genes in a variety of organs following inflammatory stimulation. Among these organs examined, kidney, bladder and prostate did not show induction of pro-inflammatory cytokine genes following irradiation. The other organs including brain, lung, liver, spleen and intestine showed different pattern of TNF-alpha, IL-1alpha, INF-gamma, IL-1beta and IL-6 gene induction, and increase of IL-1beta expression was found in all of these five organs. Our studies clearly showed that, in terms of early pro-inflammatory response, different organs respond to radiation damage in a different pattern in their type of cytokine genes, time of expression and intensity of expression. These results provide important information in our understanding radiation-induced early pro-inflammatory responses in different normal tissues.