RADIATION SENSITIVITY OF QUIESCENT TUMOR CELLS

该项目的目标是确定放射生物学和分子生物学 调节静止细胞（G-0）进入 细胞周期的增殖阶段。 静止细胞通常构成 大部分的肿瘤细胞群体，并保持克隆形成 放射治疗后。 因此，测量生长分数和 将静止细胞募集到增殖区室中的研究 对于了解肿瘤对放射治疗的反应至关重要。 使用针对增殖相关核 抗原，PCNA和Ki-67，我们建议确定1）动力学 辐射引起的静止细胞的重新分布，以及2） PLD和SLD修复后的细胞从静止到募集 增殖的隔间 特异性反义RNA的作用 对PCNA mRNA和失活蛋白质合成的影响将被评估， 确定PCNA是否是静止细胞进展为 增殖周期 这些研究将通过引入 反义RNA转染细胞，检测其对PCNA表达的影响 蛋白质和mRNA，并对细胞从静止到 增殖的隔间 随后测量PCNA蛋白和 来自被照射的静止细胞的mRNA将决定PCNA是否参与了细胞增殖。 辐射诱导静止细胞的募集。 PCNA抑制 将进行使用反义寡核苷酸的合成以确定 PCNA表达是否是辐射损伤有效修复所必需的 引发了潜在的致命伤害 我们还计划克隆cDNA并表达 人肿瘤特异性、增殖相关的核转录因子的mRNA Ki-67抗原 使用该试剂盒进行北方杂交和蛋白质印迹分析 将使用从Ki-67全长克隆cDNA制备的探针 为了评估转录和翻译调控对 辐射诱导人肿瘤中静止细胞的募集。

The goal of this project is to determine radiobiological and molecular mechanisms that regulate the entry of quiescent cells (G-0) into proliferative phases of the cell cycle. Quiescent cells often constitute a large portion of the total tumor cell population and remain clonogenic after radiation treatment. Thus, measurement of growth fraction and the study of recruitment of quiescent cells into proliferation compartment is essential for understanding the responses of tumors to radiation therapy. Using monoclonal antibodies made to proliferation associated nuclear antigens, PCNA and Ki-67, we propose to determine 1) the kinetics of radiation induced redistribution of quiescent cells, and 2) the changes in PLD and SLD repair following the recruitment of cells from quiescent to proliferating compartments. The role of specific antisense RNA that binds to the PCNA mRNA and inactivates the protein synthesis will be evaluated to determine if PCNA is required for the progression of quiescent cells into proliferating cycle. These studies will be performed by introducing antisense RNA to the cells, and then measure its effects on level of PCNA protein and mRNA, and on progression of cells from quiescent to proliferating compartments. Subsequent measurement of PCNA protein and mRNA from irradiated quiescent cells will determine if PCNA is involved in the radiation induced recruitment of quiescent cells. Suppression of PCNA synthesis using an antisense oligonucleotide will be performed to determine whether PCNA expression is necessary for efficient repair of radiation induced potentially lethal damage. We also plan to clone cDNA and express the mRNA for a human tumor specific, proliferation associated nuclear antigen, Ki-67. Northern hybridization and Western blot analysis using the probe prepared from the full length cloned cDNA of Ki-67 will be performed to evaluate the transcriptional and translational regulation on the radiation induced recruitment of quiescent cells in human tumors.