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（通过应用程序提供）：几项III期临床试验已验证了对高温治疗的使用来适应放射治疗。热疗感应哺乳动物细胞对电离辐射。因此，如果更好地理解热触觉激素化的分子机制，则在临床中使用热量的潜在益处可能会最大化。辐射会诱导DNA双链断裂（DSB）的形成，并且据信热放射敏化是由于对辐射诱导的DSB的抑制作用引起的。通常，辐射诱导的DSB修复被认为是通过两种途径进行的：非同理末端连接（NHEJ）和同源重组（HR）。 MRE11复合物已暗示在这两种途径中起作用。我们的初步数据表明，热疗会影响MRELL，RADSO和NBSL的变化，即完成MRE11复合物的蛋白质。我们还表明，热量诱导了这些蛋白质从细胞核到细胞质的转运。热诱导的改变或对MRE11复合物组件的重新分布可能会导致DSB修复效率的降低和辐射诱导的细胞杀伤的潜力。我们将测试以下方法：热射态敏化是由热诱导的改变或重新分布MRE11 DSB修复复合物引起的。我们将确定MRE11和RAD50在热触觉敏化中的作用，并确定这些蛋白质的改变是否会导致DSB修复效率的抑制或降低，而细胞后DSB修复的效率和热触觉敏感性暴露于中等温度（41.5¿C）高热度治疗。使用蛋白质印迹和共聚焦显微镜，我们将表征热诱导的热损害或重新定位MRE11，RADSO和NBSL，并试图识别发生这些改变的机制。我们还将使用靶向技术或条件突变体在特定NHEJ或HR蛋白中的有条件突变体靶向HR在热射敏化中的作用。

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