HEAT SHOCK PROTEINS AND CELL RESISTANCE TO HYPERTHERMIA

这项研究的目标是了解细胞如何抵抗热致死。 以及它们如何在存活后提高耐热性水平 体温过低。在韦伯和兰德里之间的一个合作项目中 实验室，我们发现了人类编码27 kDa热休克的基因 蛋白质在啮齿动物细胞中结构性表达，并产生热量 抗性表型。使用针对人类Hsp27蛋白的特异性抗体， 我们发现人类HSP27的数量与稳定的 转化仓鼠和小鼠细胞系及受热程度 抵抗。这些细胞系将在本研究中用于学习 HSP27在无其他热休克时是否过表达 蛋白质可以抑制形成或加速特定损伤的修复 在细胞功能和结构上，已知是由热引起的。这些 包括抑制转录、RNA加工、翻译、增加 蛋白质分解代谢和细胞骨架结构的改变。 我们还将研究hsp27的磷酸化的重要性。 蛋白质在决定对热保护的耐热性中的作用 和热敏剂。蛋白质中的磷酸化部位 将被确定以及每个地点对于热防护的意义 热休克后将通过定点突变进行评估 学习。最后，人类Hsp27基因的高构成活性 在啮齿动物细胞中将被用于开发转化的细胞系 过表达编码不同热休克蛋白的其他基因和cDNA。 每种类型的细胞系的表型将被研究 耐热性和对已知热致损伤的保护。细胞 还将培育过表达多种热休克蛋白的品系 以测试不同蛋白质之间的功能相互作用。 从这项研究中获得的信息将提供更好的理解 细胞如何应对高温，这可能导致更理性的 热疗在癌症治疗中的应用。

The goal of this study is to understand how cells resist killing by heat and how they develop increased levels of thermotolerance after surviving hypothermia. In a collaborative project between the Weber and Landry laboratories, we have found that human gene encoding the 27 kDa heat shock protein is expressed constitutively in rodent cells and produces a heat resistant phenotype. Using specific antibody to the human hsp27 protein, we find a good correlation between the amount of human hsp27 in stably transformed hamster and mouse cell lines and the degree of thermal resistance. These cell lines will be used in the present study to learn whether overexpression of hsp27 in the absence of the other heat shock proteins can inhibit formation of accelerate the repair of specific lesions in cell function and structure that are known to be caused by heat. These include inhibition of transcription, RNA processing, translation, increased protein catabolism, and alterations in the structure of the cytoskeleton. We will also investigate the importance of phosphorylation of he hsp27 protein in determining thermal resistance in response to thermoprotecting and thermosensitizing agents. The sites of phosphorylation in the protein will be determined and the significance of each site for thermoprotection following heat shock will be evaluated by site-directed mutagenesis studies. Finally, the high constitutive activity of the human hsp27 gene in rodent cells will be used to develop transformed cell lines that overexpress other genes and cDNAs encoding different heat shock proteins. The phenotype of each type cell line will be studied with respect to thermoresistance and protection from known heat induced lesions. Cell lines that overexpress multiple heat shock proteins will also be developed to test for functional interactions between the different proteins. Information obtained from this study will provide a better understanding of how cells respond the hyperthermia which could lead to more rational approaches to thermotherapy in cancer treatment.