乳腺组织是对射线敏感的组织之一，因此研究调控乳腺组织的辐射敏感性相关基因，阐明这些基因与乳腺组织辐射敏感性的关系及详细机制,对乳腺组织辐射防护的作用具有重要意义。我们前期研究结果发现提高BTG1表达,可增加乳腺细胞MCF-10A的放射敏感性;而降低BTG1表达,可减弱乳腺上皮细胞MCF-10A的辐射敏感性。本课题旨在已有研究基础上进一步从分子水平阐述BTG1调控乳腺组织辐射敏感性的作用机制:BTG1的哪个功能域和哪些关键分子相互作用发挥调控辐射敏感性的作用，并通过体内实验验证改变BTG1表达水平对乳腺组织辐射敏感性的影响。这些研究将为阐明BTG1调控乳腺组织的辐射敏感性的机制提供新的线索，为乳腺组织的辐射防护提供新的理论依据和新的分子靶点。

Breast tissue is one of the radiosensitive organs, so it is meaningful to explore the genes, which are important in regulating the sensitivity of breast tissue against ionizing radiation, and their function mechanisms for reducing the side effect of ionizing radiation on normal breast tissues. Our preliminary data suggest that the sensitivity of breast epithelial cells MCF-10A to ionizing radiation was enhanced, however, the sensitivity of breast epithelial cells MCF-10A to ionizing radiation was significantly decreased while down-regulating the expression of BTG1 in this cell line. In this project, we try to extensively explore the molecular mechanisms of BTG1 in regulating the sensitivity of breast tissue against ionizing radiation, which function domain is pivotal for this function, and which molecules will interact with this BTG1 function domain, and finally regulateing the sensitivity of breast tissue against ionizing radiation. We also try to examine this function by down-regulating or up-regulating the expression of BTG1 in vivo. Finally, these studies will provide a new clue for elucidating the mechanisms of BTG1 regulating breast tissue radiosensitivity, and supply theory evidence and a new molecular target for enhancing the radiation protection of normal breast tissue