【作者】 贺亮；

【导师】 王春喜；

【作者基本信息】 吉林大学 ， 泌尿外科， 2018， 博士

【摘要】 研究背景:前列腺癌是男性泌尿系统的重要恶性肿瘤之一,随着我国人口老龄化发展,人们生活方式的改变等原因,前列腺癌的发病率呈逐年提高的趋势。雄激素剥夺治疗(Androgen deprivation therapy,ADT)是前列腺癌的重要治疗方式之一。目前临床上应用于ADT的药物主要为促性腺激素释放激素(Gonadotropin releasing hormone,GnRh)类似物,抑那通(Enantone,ENT)是临床上主要应用的ADT药物之一,它能使雄激素一过性的提高,从而达到长时间的雄激素抑制效果。然而,激素敏感性前列腺癌常常会转变为去势抵抗性前列腺癌(Castration resistant prostate cancer,CRPC)并对雄激素剥夺治疗产生耐受。在前列腺癌由激素敏感性转为CRPC后,ADT无法取得有效的治疗效果。此时化学药物治疗作为重要的治疗方法,在CRPC的治疗中开始扮演重要的角色。蒽醌类药物如米托蒽醌(Mitoxantrone,MTO)是前列腺癌临床常用化疗药物之一。但是由于化疗药物有骨髓抑制作用、生殖系统毒性及心肝肾器官损害等许多副作用,导致其成为一种双刃剑。近年来,针对单纯雄激素剥夺治疗与化疗药物的不足,临床上进行了许多雄激素剥夺药物与化疗药物联合应用疗法试验。即针对高负荷的雄激素敏感前列腺癌患者,在治疗的开始就联合应用化疗药物与ADT药物。这种化学激素疗法可以明显延长前列腺癌患者的生存时间,并且减缓肿瘤的进展速度。基于这种化学激素疗法的基本理念,如何更有效联合两种治疗方式的优点,提高药物缓释与靶向效果,并降低这种治疗方式带来的副作用将是未来研究的关键。生物可降解纳米材料运载药物体系由于其较好的控制缓释效果、智能靶向肿瘤组织以及减少药物的副作用等良好性能,在近年来得到了广泛的研究。因此,将生物可降解纳米材料与化学激素疗法相结合是我们本课题设计的基本理念。实验目的:探究环境响应性生物降解材料辅助化学激素疗法的抗肿瘤效果。实验方法:首先,我们设计了酸性响应性的聚乙二醇聚谷氨酸(mPEG-b-PLG)纳米胶束(PM),用其装载MTO形成PM/MTO胶束化药物,与ENT联合治疗PCa。我们对PM/MTO进行了材料表征(质子核磁共振谱、红外光谱表征、粒径大小、释放情况)、细胞毒性实验、细胞内吞实验、药物组织分布及药代动力学实验,并联合ENT进行体内抑瘤实验。随后,我们设计了聚乙二醇-丙氨酸(mPEG-PLALa)温敏性凝胶,用其装亮丙瑞林(LEU)药物替代ENT的功能。同时我们还合成了还原敏感聚乙二醇-苯丙氨酸-胱氨酸(mPEG-Cys-Phe)纳米凝胶共载阿霉素(Doxorubicin,DOX)与比卡鲁胺(Bicalutamide,BCL)药物。我们对这两种纳米凝胶材料进行了材料表征(质子核磁共振谱、红外光谱表征、粒径检测及药物释放检测)、细胞实验表征(还原敏感细胞毒性实验与细胞内吞实验)、动物体内实验(温敏凝胶降解实验、药代动力学检测、药物组织分布检测、联合应用温敏型凝胶与还原敏感纳米凝胶体内PCa抑制实验)。实验结果:我们发现,pH敏感的纳米胶束可以提高PM/MTO药物在血液中的缓释效果,PM/MTO在PCa荷瘤鼠模型中明显提高了肿瘤组织中的药物分布浓度。并且与游离MTO药物相比,PM/MTO延长了1.8倍的半衰期,从而提高了循环系统中的药物浓度。在PM/MTO联合ENT治疗PCa荷瘤鼠实验中,PM/MTO与ENT联合应用可以显著抑制肿瘤的进展、降低荷瘤鼠雄激素水平并减轻MTO化疗药物的副作用。同时我们还发现,温敏型凝胶可以在生理环境下稳定降解、并且很好的在体内与体外缓释LEU药物,起到降低雄激素水平的作用。而还原敏感凝胶有着稳定的纳米粒径(半径~50 nm),并且可以高效地装载DOX与BCL药物。这种还原敏感凝胶可以很好的提高药物在荷瘤鼠肿瘤2组织中的蓄积浓度,延长体内半衰期并降低药物的清除率。这种还原敏感凝胶可以通过DOX的细胞毒性作用与BCL的雄激素受体拮抗作用抑制PCa的进展。而在动物实验中,这种系统整体化的纳米材料辅助化学激素疗法在荷瘤鼠体内PCa抑制实验中可以明显的抑制肿瘤生长、降低PCa的转移率、显著降低雄激素水平并将其维持在较低水平、降低药物副作用并提高实验鼠的生存率。实验结论:1、环境响应性高分子纳米材料对前列腺癌化学激素疗法有着明显的提高作用。2、高分子纳米材料将化学治疗与激素治疗相结合的治疗理念,将在未来为PCa的化学激素治疗提供更多的策略。更多还原

【Abstract】 Background:Prostate cancer(PCa)is one of the most important maligancies in male urinary system.With the development of the aging population in our country and changes in people’s lifestyles,the incidence of PCa is increasing year by year.Clinically,the main treatment methods for PCa are: surgical treatment,radiation therapy,endocrine therapy and chemotherapy.Androgen deprivation therapy(ADT is the first choice for PCa patients.The currently clinical drugs used for ADT are mainly Gonadotropin releasing hormone(GnRH)analogues,which can regulate the production of androgens in hypothalamic-pituitary-testosterone pathway.GnRH can reduce the body’s androgen level.which can cause transient increase of androgen and achieve long-term androgen suppression.However,the clinically hormone-sensitive prostate cancer often turns into castration resistant prostate cancer(CRPC)and develops resistance to ADT.When the PCa progresses to CRPC,ADT was unable to obtain effective outcomes for PCa patients.Then,chemotherapy begins to play an important role in the treatment of CRPC.Paclitaxel drugs such as docetaxel(DTX),anthracyclines such as Mitoxantrone(MTO)and Doxorubicin(DOX)are commonly used in clinical chemotherapy for PCa.However,chemotherapy drugs have many side effects,such as myelosuppression,reproductive system toxicity,and damages to organs.In recent years,the combinations of ADT and chemotherapy have been researched clinically.For patients with high-burdern androgen-sensitive PCa,chemotherapy drugs and ADT drugs are combined at the beginning of treatment.The chemohormonal therapy can significantly prolong the survival of PCa patients,and slow the progression and metastasis of PCa.Based on the concept of this chemohormonal therapy,how to more effectively combine the advantages of the two treatment,improve the drug’s sustained release,enhance the targeting effects,and reduce the side effects of this treatment will be the key in future research.The biodegradable nanomaterial delivery drug system has been widely studied recently due to its good control of slow release effect,intelligent targeting of tumor tissues,and reduction of side effects of chemotherapy drugs.Therefore,the combination of biodegradable nanomaterials and chemohormonal therapy is the basic idea of this topic.ObjectiveInvestigate the anti-PCa effect by environment-responsive nanocarriers assisted chemohormonal therapy.MethodsFirst,we designed an acid-responsive mPEG-b-PLG nanomicelle(PM),which was loaded with MTO to form a PM/MTO micelle drug and combined with ENT to treat PCa.We performed material characterization(proton nuclear magnetic resonance spectroscopy,FT-IR spectroscopy,particle size distribution,and in vitro release),cytotoxicity experiments,endocytosis,drug biodistribution,and pharmacokinetics of PM/MTO,Then,we performed in vivo anti-PCa experiments by PM/MTO and ENT.Subsequently,we designed a mPEG-PLALa thermo-responsive gel loaded leuprolide(LEU)to replace the ENT.At the same time,we also synthesized reduced-sensitive PEG-Cys-Phe NGs containing Doxorubicin(DOX)and Bicalutamide(BCL).We characterized these two nanogels by material characterization(proton nuclear magnetic resonance spectroscopy,FT-IR spectroscopy,particle size detection,and drug releasing experiment),cell experiments(reduction-responsive cytotoxicity and endocytosis),and animal studies(thermal-sensitive gel degradation test,pharmacokinetics detection,drug biodistribution detection,combined application of temperature-sensitive gel and reduction-sensitive nano-gel in vivo PCa inhibition test).ResultsIn the first part,we combined pH-sensitive nanomicelles with commercial LEU microspheres.These pH-sensitive nanomicelles can increase the sustained release of MTO drugs in the blood and increase the drug concentration in tumor tissues.And significant reduce the side effects.In the second part,we designed and synthesized two kinds of nanogels,PEG-b-ALA thermo-sensitive gel and PEG-Cys-Phe reduction-sensitive NGs.Thermal-sensitive gel can release LEU drugs in vivo,and reduce androgen levels.The reduction-sensitive NGs can effectively carry DOX and BCL drugs,and inhibit the progression of PCa by cellular cytotoxicity and androgen receptor antagonism.This systemetic nanomaterial-assisted chemohormonal therapy can significantly inhibit tumor growth and decrease androgen levels in PCa tumor allografted mice models.Conclusion 1.The environment-responsive polymer nano materials has a significant effect on the improvement of prostate cancer chemohormonal therapy.2.This therapeutic idea of using polymer nanomaterials to combine chemotherapy with hormone therapy will provide more strategies for PCa’s treatment of chemohormonal therapy in the future.更多还原