The Role of the Mre11 Complex in Heat-radiosensitization

Mre11 复合物在热放射增敏中的作用

• 批准号: 7279131
• 负责人: JOSEPH R DYNLACHT
• 金额: $ 22.44万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7279131
• 关键词: Adjuvant; Back; Biological Assay; Cell Line; Cell Nucleus; Cells; Chemosensitization; Chronic; Clinic; Complex; Confocal Microscopy; Cytoplasm; DNA Double Strand Break; Data; Dose; Double Strand Break Repair; Fever; Heating; Induced Hyperthermia; Ionizing radiation; Kinetics; Lead; Mammalian Cell; Measures; Molecular; Nonhomologous DNA End Joining; Nuclear; Pathway interactions; Pattern; Phase III Clinical Trials; Play; Principal Investigator; Process; Protein translocation; Proteins; RNA Interference; Radiation; Radiation induced double strand break; Radiation therapy; Radiosensitization; Recovery; Repair Complex; Research; Role; Techniques; Technology; Temperature; Testing; Western Blotting; cell killing; clinically relevant; functional loss; homologous recombination; hyperthermia treatment; inhibitor/antagonist; insight; irradiation; mutant; programs; radiation effect; recombinational repair; repaired

DESCRIPTION (provided by applicant): Several phase III clinical trials have validated the use of hyperthermia as an adjuvant to radiation therapy. Hyperthermia sensitizes mammalian cells to ionizing radiation. Therefore, the potential benefit of using heat in the clinic may be maximized if the molecular mechanisms for heat-radiosensitization are better understood. Radiation induces the formation of DNA double strand breaks (DSBs), and thermal radiosensitization is believed to be caused by an inhibition of repair of radiation-induced DSBs by heat. Normally, radiationinduced DSB repair is believed to occur via two pathways: non-homologous end-joining (NHEJ) and homologous recombination (HR). The Mre11 complex has been implicated to function in both of these pathways. Our preliminary data suggest that hyperthermia induces alterations to Mrell, RadSO and Nbsl, the proteins comprising the Mre11 complex. We have also shown that heat induces the translocation of these proteins from the nucleus to the cytoplasm. Heat-induced alterations to, or redistribution of the components of the Mre11 complex could result in a decrease in DSB repair efficiency and potentiation of radiationinduced cell killing. We will test the-hypothesis that heat-radiosensitization is caused by heat-induced alterations to, or redistribution of proteins of the Mre11 DSB repair complex. We will determine the role of Mre11 and Rad50 in heat-radiosensitization, and determine whether alterations of these proteins lead to an inhibition or decrease in the efficiency of DSB repair and heat-radiosensitization after cells are exposed to moderate temperature (41.5¿C) hyperthermia treatments. Using Western blotting and confocal microscopy, we will characterize heat-induced thermal damage to, or relocalization of Mre11, RadSO, and Nbsl and attempt to identify the mechanisms by which these alterations occur. We will also determine the role of HR in heat-radiosensitization using silencing RNA (siRNA) targeting technology or conditional mutants deficient in specific NHEJ or HR proteins.

描述(由申请人提供)：几个III期临床试验已经证实了高温作为放射治疗的辅助手段的使用。高温使哺乳动物细胞对电离辐射敏感。因此，如果更好地了解热放射增敏的分子机制，在临床上使用热的潜在好处可能是最大的。辐射诱导DNA双链断裂(DSB)的形成，而热辐射增敏是由于热抑制辐射诱导的DSB的修复所致。通常认为，辐射诱导的DSB修复通过两条途径发生：非同源末端连接(NHEJ)和同源重组(HR)。Mre11复合体被认为在这两条通路中都有作用。我们的初步数据表明，高温导致Mrell、RadSO和Nbsl发生变化，这些蛋白质组成了Mre11复合体。我们还表明，热诱导这些蛋白质从细胞核到细胞质的移位。热诱导的Mre11复合体成分的改变或重分布可能导致DSB修复效率的降低和辐射诱导的细胞杀伤的增强。我们将检验这一假设，即热辐射增敏是由热诱导Mre11 DSB修复复合体的蛋白质改变或重新分布引起的。我们将确定Mre11和Rad50在热放射增敏中的作用，并确定在细胞暴露于中温(41.5℃)高温处理后，这些蛋白的变化是否会导致DSB修复和热放射增敏效率的抑制或降低。使用免疫印迹和共聚焦显微镜，我们将表征热诱导的热损伤或Mre11、RadSO和Nbs1的重新定位，并试图确定这些变化发生的机制。我们还将利用沉默RNA(SiRNA)靶向技术或缺乏特定NHEJ或HR蛋白的条件突变来确定HR在热辐射增敏中的作用。

项目成果

A tool for enhancement and scoring of DNA repair foci.

DNA 修复焦点增强和评分的工具。

• DOI: 10.1002/cyto.a.20653
• 发表时间: 2009
• 期刊: Cytometry. Part A : the journal of the International Society for Analytical Cytology
• 作者: Gerashchenko,BogdanI;Dynlacht,JosephR
• 通讯作者: Dynlacht,JosephR

Hyperthermia alters the interaction of proteins of the Mre11 complex in irradiated cells.

高温会改变受辐射细胞中 Mre11 复合体蛋白质的相互作用。

• DOI: 10.1002/cyto.a.20955
• 发表时间: 2010
• 期刊: Cytometry. Part A : the journal of the International Society for Analytical Cytology
• 作者: Gerashchenko,BogdanI;Gooding,Gerirose;Dynlacht,JosephR
• 通讯作者: Dynlacht,JosephR