PSMA靶向外泌体介导siRNA改善去势抵抗性前列腺癌谱系可塑性的实验研究

Advanced castration-resistant prostate cancer (CRPC) is the focus and difficulty of the final outcome and treatment of prostate cancer. Recent studies suggest that lineage plasticity is the key to its resistance. RNAi as a new technology for tumor treatment has broad prospects, but there are bottlenecks such as poor targeting of effect molecules, low transport efficiency and target selection. Recently, it has been confirmed that exosomes can be used as an effective delivery vehicle for siRNA. Based on the previous research on targeted therapy of prostate cancer, the research team directly transformed exosomes to have PSMA targeting, and delivered siRNA to CRPC cells for key genes affecting their epigenetic plasticity, and explored siRNA-exosome couples. The anti-CRPC effect and related mechanisms in vitro and in vivo. The advantage of this strategy is to utilize the natural characteristics of exosomes and the targeting of PSMA antibodies, and to deliver different functional siRNAs with low toxicity and high efficiency, in order to change the lineage plasticity of CRPC at epigenetic level, to reverse or prolong the process of hormone resistance transformation, Obtaining androgen sensitivity, thereby improving drug resistance and improving conventional efficacy. The aim is to use a new targeted, efficient and low-toxic siRNA delivery method for the clinical treatment of prostate cancer.

晚期去势抵抗型前列腺癌（CRPC）是前列腺癌的最终结局和治疗的重点及难点。最近研究提示谱系可塑性是造成其耐药的关键。RNAi作为肿瘤治疗新技术前景广阔，但存在效应分子靶向性差、转运效率低和靶点选择等瓶颈。而最新证实外泌体能作为siRNA的有效递送载体。课题组在前期对前列腺癌靶向治疗研究基础上，直接改造外泌体使之具有PSMA靶向性，向CRPC细胞输送针对影响其表观遗传塑性关键基因的siRNA，探索siRNA-外泌体偶联物在体内外抗CRPC作用和相关机制。该策略优势在于利用外泌体的天然特性和PSMA抗体的靶向性，低毒高效输送不同功能siRNA，以期在表观遗传学层面改变CRPC的谱系塑性，扭转或延长激素抗性转变过程，重获雄激素敏感性，从而改善耐药提高常规疗效。旨在用一种新的前列腺癌靶向、高效、低毒的siRNA递送方法，为去势抵抗前列腺癌的临床治疗寻找的新方法和开辟新途径。

晚期去势抵抗型前列腺癌（CRPC）是前列腺癌的最终结局和治疗的重点及难点。最近研究提示谱系可塑性是造成其耐药的关键。RNAi作为肿瘤治疗新技术前景广阔，但存在效应分子靶向性差、转运效率低和靶点选择等瓶颈。而最新证实外泌体能作为siRNA的有效递送载体。课题组在前期对前列腺癌靶向治疗研究基础上，直接改造外泌体使之具有PSMA靶向性，向CRPC细胞输送针对影响其表观遗传塑性关键基因的siRNA，探索siRNA-外泌体偶联物在体内外抗CRPC作用和相关机制。. 我们利用前期从人类天然scFv库中筛选出的最合适的高亲和力PSMA人源化单抗gy1，与外泌体的质膜表面蛋白 Lamp2b 用基因工程的方法进行融合，构建 PMSA-ScFv-Lamp2b 质粒，用慢病毒包装质粒后感染293t细胞，提取细胞上清外泌体PSMA-exo，体内外证实构建的靶向外泌体PSMA-exo可以靶向PSMA阳性的前列腺癌细胞和裸鼠体内肿瘤部位，靶向效果良好。用瞬时转染的方法，把EZH2-siRNA转染入PSMA-exo，构建携带EZH2siRNA的靶向外泌体PSMA-exo-EZH2siRNA，作用于激素非依赖的前列腺癌细胞，经CCK8, 划痕和transwell实验初步证实可以减缓肿瘤的增殖，迁移和侵袭作用。后期还将探讨PSMA-exo-EZH2siRNA处理的细胞是否能恢复AR的敏感性，以及和抗雄药物恩杂鲁胺联合作用后是否能提高药物的治疗效果同时低毒安全高效。. 该策略优势在于利用外泌体的天然特性和PSMA抗体的靶向性，低毒高效输送不同功能siRNA，以期在表观遗传学层面改变CRPC的谱系塑性，扭转或延长激素抗性转变过程，重获雄激素敏感性，从而改善耐药提高常规疗效。旨在用一种新的前列腺癌靶向、高效、低毒的siRNA递送方法，为去势抵抗前列腺癌的临床治疗寻找的新方法和开辟新途径。