双模态纳米造影剂Au@MnO-Tf通过自噬介导的光、化疗协同增敏靶向诊疗前列腺癌的效应与机制研究

It is of great importance and also quite an effort to explore the noninvasive and sensitive prostate cancer (PCa) diagnostic methods, as well as the novel approaches to achieving effective hormone refractory prostate cancer (HRPC) therapy. Based on our previous publications, we have found that manganese oxide nanocrystals (MnO NCs) can efficiently to serve as an excellent T1 magnetic.resonance imaging (MRI) contrast agent and elicit autophagy-mediated chemotherapeutic cancer killing effect. Meanwhile, our latest study has originally revealed that gold nanorods (Au NRs) can also induce genuine autophagy and enhance the near-infrared light-based tumoricidal activity in prostate cancer cells. Thus, in the present project, we intend to integrate MnO NCs with Au NRs and also conjugate the active targeting motif transferrin (Tf) to them and eventually obtain the multifunctional nano-sized Au@MnO-Tf, which nanomaterials can obviously enhance the MRI and X-ray computed tomography (CT) dual-modal imaging contrast to diagnose prostate cancer. Simultaneously, Au@MnO-Tf can effectively achieve the targeted synergistic chemotherapeutic and photothermal sensitization effect to killing HRPC, based on the synergistic and reciprocally-enhanced autophagy induction elicited by MnO NCs and Au NRs. Furthermore, via the inhibitors administration and siRNA knockdown, we expect to elucidate the role of autophagy and molecular mechanism underlying modulation of the synergistic destruction of prostate cancer. In summary, the current proposal is designed to utilize cancer nanotechnology which integrates cancer imaging, cellular and molecular biology to illuminate the effects and correlated mechanisms of the targeted theragnosis to prostate cancer elicited by multifunctional nanomaterials Au@MnO-Tf in vitro and in vivo, which could shed light on some valuable ideas and feasible approaches for clinical theragnosis of prostate cancer and follow-up investigations.

探索前列腺癌(PCa)的无创、灵敏诊断方法及激素抵抗性前列腺癌(HRPC)的新疗法是当今该领域研究的重点与难点。申请人已发表论文显示纳米氧化锰(MnO)具有增强MRI对比度同时诱导自噬增强化疗杀伤的能力。同时，我们的前期研究揭示金纳米棒(AuNRs)可通过诱导自噬增强近红外光热对前列腺癌的杀伤。因此，本项目拟将MnO与Au复合并偶联靶向分子转铁蛋白(Tf)合成出纳米Au@MnO-Tf，在显著增强MRI/CT双模态成像对比度的同时，利用MnO和Au协同诱导自噬并交互增强的特性，有效实现对HRPC基于化疗、光疗的靶向协同增敏杀伤。最后，通过多种抑制剂及siRNA的使用，初步揭示自噬在其中扮演的重要角色及分子调控机制。综上，本项目拟综合运用涵盖了多个学科的癌症纳米技术，通过一系列体内外实验阐明Au@MnO-Tf实现PCa靶向协同诊疗一体化的效应与机制，有望为临床PCa诊疗及相关研究提供新的思路。

探索前列腺癌等癌症的无创、灵敏诊断方法及有效的治疗手段是当今该领域研究的重点与难点。本项目针对上述科学问题，设计合成了多种诊疗型纳米材料，并探讨了前列腺癌治疗过程中的瓶颈问题与相关分子生物学机制，具体取得了如下研究成果：①设计并合成出具有靶向前列腺癌能力的Au@MnO-Tf纳米材料，并实现了其基于Mn元素的靶向磁共振成像（MRI）造影对比增强以诊断前列腺癌，同时明确了其通过化疗、近红外光疗杀伤前列腺癌的增敏效应与自噬调控机制，评估了纳米Au@MnO-Tf靶向前列腺癌“诊疗一体化”的能力；②设计并合成出聚乙二醇与叶酸修饰的蛋黄样Fe3O4@Gd2O3纳米材料，证明其具有较临床上使用的造影剂组分更高的纵向弛豫率(r1)和横向弛豫率(r2)，有效实现了其对癌症的T1/T2双模态MRI造影对比增强，同时证实该纳米材料在载负抗癌药顺铂后，可在体内外水平实现对癌症的有效杀伤，最终达成对癌症的“诊疗一体化”；③设计并合成出MnFe2O4纳米颗粒，发现其可以通过泛素-蛋白酶体途径而非自噬-溶酶体途径增强前列腺癌相关雄激素受体结构蛋白多聚谷氨酰胺（Qn）的降解，有望为降解雄激素受体从而治疗前列腺癌提供新的思路；④总结分析出细胞自噬可能是前列腺癌抗雄激素治疗效果不佳的重要原因，人E3泛素蛋白连接酶（CHIP）可以在负向调控缺氧诱导因子-1α（HIF-1α）的同时，拮抗前列腺癌中通常表达升高的miR-21对细胞迁移的促进作用，为未来前列腺癌治疗提供了新的药物靶点。项目执行期间共发表论文13篇，其中SCI收录12篇；授权国家发明专利1项；项目负责人受邀作学术会议报告/优秀论文报告3次；获安徽省科技进步一等奖、中华医学科技二等奖各1项（均为第4完成人）、安徽医学科学技术一等奖1项（第六完成人）；协助培养博士研究生2名、硕士研究生3名。