Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China.
Movement System Injury and Repair Research Center, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China.
Int J Nanomedicine. 2021 Apr 20;16:2949-2963. doi: 10.2147/IJN.S304515. eCollection 2021.
Prostate cancer (PCa) is one of the most common malignancies in males. Despite the success of immunotherapy in many malignant cancers, strategies are still needed to improve therapeutic efficacy in PCa. This study aimed to investigate the effects of -derived extracellular vesicles (-EVs) on PCa and elucidate the underlying immune-related mechanism.
-EVs were isolated by ultracentrifugation and intravenously injected to treat syngeneic PCa-bearing immune-competent mice. Immunophenotypic changes in immune cells, such as cytotoxic T lymphocytes and macrophages, were measured via flow cytometry analysis. Histological examination was used to detect morphological changes in major organs after -EVs treatments. In vitro, flow cytometry was performed to confirm the effects of -EVs on the activation of CD8 T cells. Quantitative PCR and immunofluorescence staining were carried out to test the impact of -EVs on macrophage polarization. Cell counting kit-8 (CCK-8) analysis, colony formation assays, and scratch wound healing assays were conducted to assess the effects of -EVs-treated macrophages on the proliferation and invasion of PCa cells. CCK-8 assays also confirmed the impact of -EVs on the viability of normal cells.
Intravenous injection of -EVs in immune-competent mice reduced the tumor burden of PCa without inducing obvious toxicity in normal tissues. This treatment elevated the proportion of granzyme B-positive (GZMB) and interferon γ-positive (IFN-γ) lymphocytes in CD8 T cells and caused macrophage recruitment, with increased tumor-killing M1 macrophages and decreased immunosuppressive M2 macrophages. In vitro, -EVs increased the number of GZMBCD8 and IFN-γCD8 T cells and M1-like macrophages. In addition, conditioned medium from -EVs-treated macrophages suppressed the proliferation and invasion of prostate cells. Furthermore, the effective dose of -EVs was well-tolerated in normal cells.
Our study revealed the promising prospects of -EVs as an efficient and biocompatible immunotherapeutic agent for PCa treatment.
前列腺癌（PCa）是男性最常见的恶性肿瘤之一。尽管免疫疗法在许多恶性肿瘤中取得了成功，但仍需要策略来提高 PCa 的治疗效果。本研究旨在探讨 -衍生的细胞外囊泡（-EVs）对 PCa 的影响，并阐明其潜在的免疫相关机制。
通过超速离心法分离 -EVs，并静脉注射治疗同源性 PCa 荷瘤免疫功能正常的小鼠。通过流式细胞术分析测量免疫细胞（如细胞毒性 T 淋巴细胞和巨噬细胞）的免疫表型变化。组织学检查用于检测 -EVs 治疗后主要器官的形态变化。在体外，通过流式细胞术证实 -EVs 对 CD8 T 细胞激活的影响。实时定量 PCR 和免疫荧光染色用于检测 -EVs 对巨噬细胞极化的影响。细胞计数试剂盒-8（CCK-8）分析、集落形成实验和划痕愈合实验用于评估 -EVs 处理的巨噬细胞对 PCa 细胞增殖和侵袭的影响。CCK-8 分析还证实了 -EVs 对正常细胞活力的影响。
在免疫功能正常的小鼠中静脉注射 -EVs 可减轻 PCa 的肿瘤负担，而不会在正常组织中引起明显的毒性。这种治疗方法增加了 CD8 T 细胞中颗粒酶 B 阳性（GZMB）和干扰素 γ 阳性（IFN-γ）淋巴细胞的比例，并引起巨噬细胞募集，增加了杀伤肿瘤的 M1 巨噬细胞，减少了免疫抑制的 M2 巨噬细胞。在体外，-EVs 增加了 GZMB+CD8 和 IFN-γ+CD8 T 细胞和 M1 样巨噬细胞的数量。此外，来自 -EVs 处理的巨噬细胞的条件培养基抑制了前列腺细胞的增殖和侵袭。此外，-EVs 的有效剂量在正常细胞中具有良好的耐受性。
本研究揭示了 -EVs 作为治疗 PCa 的有效且生物相容的免疫治疗剂的广阔前景。
