新型17-AAG复合型纳米药物在辐射防护中的生物作用及其调控机制的研究

Heat shock protein 90 (Hsp90) is an ubiquitous molecular chaperone protein, which is involved in folding, activation and assembly of many proteins. Hsp90 is also the key mediators of signal transduction, cell-cycle control, cellular growth, differentiation, apoptosis and transcriptional regulation. 17-allylamino-17-demethoxygeldanamycin (17-AAG) is an Hsp90 inhibitor that protected of normal cells from irradiation and selectively enhanced the raidiosensitivity of tumor cells by blocking the formation of multi-chaperone complexes of Hsp90. Our previous study found the copolymers consisting of monomethoxy poly(ethylene glycol) and alkylamine-grafted poly(L-aspartic acid) that was assembled with carbocyanine dyes (Cypate) into theranostic micelles, plays an important role in killing cancer cell by releasing free radicals. On the basis of this finding, we further reconstruct the new micelles complexes, which was assembled with 17-AAG and Cypate, and study the micelles that exhibit the radiosensitizing effects on tumor cells while had no effects on normal cells. The mecelles will be measured with the parameters, like particle size, polydispersity index (PDI), entrapment efficiency and drug-loading. The radiosensitivity relevant to the cell growth signal pathway and DNA damage repair pathway will be investigated. Other concerning mechanisms will be explored through the technique of lncRNA microarray. Our study aims to explain the molecular mechanisms of enhanced radiosenitivity with the new micelles complexes and provide evidence for the usage in the future..

热休克蛋白HSP90是细胞分子伴护蛋白，维持基因稳定，调控细胞生长，分化和凋亡等生物过程。17-AAG阻断HSP90复合体形成对正常细胞起到辐射防护的同时，增强肿瘤细胞辐射敏感性。我们发现吲哚菁绿的羧基衍生物Cypate纳米胶束作为光热治疗剂的同时，释放自由基杀伤细胞。通过对聚氧乙烯-b-聚氨基酸嵌段的修饰，将17-AAG，Cypate包载构成新型功能复合型聚合物胶束。本课题主要研究纳米聚合物胶束17-AAG/Cypate对正常细胞辐射防护的同时，对肿瘤细胞辐射敏感性的影响及其调控机制。首先以纳米粒径，包封率和载药量等指标对纳米聚合物胶束进行优化，观察药物对细胞辐射防护/敏感性的影响；其次探讨相关生存信号通路，DNA修复通路的变化；进而通过lncRNA基因芯片技术研究诱导细胞辐射生物变化的其它调控基因，全面了解17AAG/Cypate聚合物胶束相关的辐射防护与增敏机制，为临床应用提供依据。

热休克蛋白HSP90是细胞分子伴护蛋白，维持基因稳定，调控细胞生长，分化和凋亡等生物过程。17-AAG阻断HSP90复合体形成对正常细胞起到辐射防护的同时，增强肿瘤细胞辐射敏感性。我们发现吲哚菁绿的羧基衍生物Cypate纳米胶束作为光热治疗剂的同时，释放自由基杀伤细胞。通过对聚氧乙烯-b-聚氨基酸嵌段的修饰，将17-AAG，Cypate包载构成新型功能复合型聚合物胶束。本课题主要研究纳米聚合物胶束17-AAG/Cypate对正常细胞辐射防护的同时，对肿瘤细胞辐射敏感性的影响及其调控机制。首先以纳米粒径，包封率和载药量等指标对纳米聚合物胶束进行优化，观察药物对细胞辐射防护/敏感性的影响；其次探讨相关生存信号通路，DNA修复通路的变化；进而通过miRNA基因芯片技术，lncRNA基因芯片技术和蛋白质芯片技术进而研究诱导细胞辐射生物变化的其它调控基因，全面了解17AAG/Cypate聚合物胶束相关的辐射防护与增敏机制。我们首先以纳米粒径，包封率和载药量等指标对17-AAG/Cypate复合性纳米聚合物胶束进行优化，测定细胞对聚合物胶束摄取量，观察纳米药物对正常细胞辐射防护的保护作用，同时比较17AAG，17AAG单包胶束和17AAG/Cypate聚合物胶束对在X射线照射，联合激光照射下，对肿瘤辐射敏感性的影响；实验结果显示：17-AAG对正常细胞抵抗辐射有一定的防护作用；但相较于其他包载形式，17-AAG/Cypate复合性纳米聚合物胶束对肿瘤细胞具有显著的辐射增敏作用；主要通过诱导细胞凋亡，调控细胞周期，抑制DNA损伤修复机制，诱导细胞老化，阻碍血管新生影响肿瘤细胞内微环境等联合作用，达到辐射增敏效应。在miRNA基因芯片数据分析中，筛选出可能影响辐射增敏作用的4组miRNA，进行进一步的研究论证。课题旨在全面了解与新型复合性纳米聚合物胶束17AAG-Cypate相关的辐射防护和辐射增敏机制，为临床应用提供依据。