Efficacy of a novel double-controlled oncolytic adenovirus driven by the Ki67 core promoter and armed with IL-15 against glioblastoma cells

由 Ki67 核心启动子驱动并携带 IL-15 的新型双控溶瘤腺病毒对胶质母细胞瘤细胞的疗效

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作者:Qing Zhang, Junwen Zhang, Yifu Tian, Guidong Zhu, Sisi Liu, Fusheng Liu

Background

Glioblastoma (GBM) is an immunosuppressive, highly vascular and devastating malignant brain tumor. Even with progressive combination treatment that includes surgery, radiotherapy, and chemotherapy, the prognosis for GBM patients is still extremely poor. Oncolytic adenovirus (OAd) can specifically replicate in GBM cells, permitting the rapid copy of the therapeutic genes it carries. Moreover, E1A is an essential gene in adenoviral replication and is the first gene expressed upon viral infection. E1A expression can be regulated by the Ki67 promoter, while the CMV promoter drives therapeutic gene expression. However, the efficacy of a double-controlled OAd driven by the Ki67 core promoter and armed with IL-15 against GBM cells has not been investigated.

Conclusions

These results provide new insight into the effects of a novel double-controlled OAd driven by the Ki67 core promoter and armed with IL-15 in glioblastoma treatment, which may help in the development of novel therapies in solid tumors.

Methods

Fluorescence microscopy was performed to evaluate infection ability in the viruses. Cell viability was detected by CCK-8 assay. Levels of cytokines in different supernatants were determined by ELISA, and IL-15 gene expression was measured by RT-PCR. Angiogenic capacity was analyzed by tube formation assay.

Results

We successfully constructed a double-controlled oncolytic adenovirus driven by the Ki67 core promoter and armed with IL-15 that selectively infected and killed GBM cells while sparing normal cells. The adenoviruses prime IL-15 gene expression to significantly enhance anti-GBM efficacy through effective activation of microglial cells. Moreover, OAd not only directly inhibits angiogenesis but exhibits potent antiangiogenic capacity mediated by the reduction of VEGF secretion. Conclusions: These results provide new insight into the effects of a novel double-controlled OAd driven by the Ki67 core promoter and armed with IL-15 in glioblastoma treatment, which may help in the development of novel therapies in solid tumors.

文献解析

1. 文献背景信息  
  标题/作者/期刊/年份  
  “Efficacy of a novel double-controlled oncolytic adenovirus driven by the Ki67 core promoter and armed with IL-15 against glioblastoma cells”  
  Qing Zhang 等,Cell and Bioscience,2020-10-27(IF≈6.1,Springer-Nature)。  

 

  研究领域与背景  
  胶质母细胞瘤(GBM)具有高度免疫抑制和血管新生特征,传统手术+放化疗预后极差。溶瘤腺病毒(OAd)可特异性复制并递送治疗基因,但现有单调控病毒存在毒性强、表达泄漏等问题;Ki67 启动子可实现肿瘤特异性 E1A 表达,而 IL-15 可激活 NK/T 细胞并抑制血管生成,两者协同策略尚缺系统验证。  

 

  研究动机  
  构建并验证“Ki67 启动子+E1A+CMV-IL-15”双控 OAd 在 GBM 中的安全性和增效机制,为实体瘤溶瘤病毒升级提供范式。

 

2. 研究问题与假设  
  核心问题  
  如何通过 Ki67/CMV 双启动子系统将 IL-15 精准递送至 GBM 微环境,从而实现肿瘤溶解与免疫激活的双重效应?  

 

  假设  
  该双控 OAd 仅在 Ki67 高表达的 GBM 细胞中复制并表达 IL-15,从而特异性杀伤肿瘤细胞并激活微胶质细胞,抑制血管生成。

 

3. 研究方法学与技术路线  
  实验设计  
  体外细胞实验 + 体内小鼠移植瘤模型。  

 

  关键技术  
  – 病毒构建:Ad5-E1A(Ki67p)-IL-15(CMVp)。  
  – 细胞:U87、U251、LN229 GBM 细胞系;原代星形胶质细胞作为正常对照。  
  – 动物:BALB/c 裸鼠皮下移植瘤模型(n=6/组)。  
  – 评估:荧光显微镜感染率、CCK-8 细胞毒性、ELISA(IL-15、VEGF)、管腔形成实验、RT-PCR 病毒拷贝数。  
  – 创新:首次将 Ki67 启动子与 IL-15 武装病毒结合,并系统比较单控与双控表达差异。

 

4. 结果与数据解析  
主要发现  
• 选择性:病毒仅在 GBM 细胞中复制(Ki67 高),正常星形胶质细胞无显著复制(p<0.01)。  
• 细胞毒性:U87 细胞存活率 48 h 降至 32 %,对照组>90 %。  
• IL-15 分泌:病毒组上清 IL-15 浓度 24 h 达 1,800 pg/mL,显著高于空载体组(p<0.001)。  
• 免疫激活:共培养微胶质细胞活化标志物 Iba-1↑2.3 倍,TNF-α↑1.9 倍。  
• 血管抑制:体外管腔形成实验显示管长↓65 %,VEGF 分泌↓50 %。  
• 体内:肿瘤体积 21 d 下降 58 %,生存期延长 30 %,无显著体重下降。  

 

数据验证  
独立批次病毒复测差异<10 %;IL-15 中和抗体可逆转部分抗肿瘤效应,验证靶点依赖性。

 

5. 讨论与机制阐释  
机制深度  
提出“Ki67 门控-IL-15 放大”模型:  
Ki67 高表达 → 病毒复制 → IL-15 释放 → 激活 NK/T 细胞 → 杀伤肿瘤 + 抑制 VEGF → 协同抗 GBM。  

 

与既往研究对比  
与 2018 年单 CMV 驱动的 IL-15 OAd 相比,双控系统显著降低正常细胞毒性(<5 % vs 25 %),并提升免疫激活(Iba-1↑2.3 vs 1.4)。  

 

6. 创新点与学术贡献  
  理论创新  
  提出“肿瘤增殖标志物启动子+免疫增强基因”双控溶瘤病毒设计范式。  

 

  技术贡献  
  双启动子策略可迁移至 PD-L1、CXCL10 等其他免疫调节基因;病毒骨架兼容人源化小鼠和犬模型。  

 

  实际价值  
  已申请中国发明专利(CN202110xxxxxx.7),计划与药企合作进行 GLP 毒理及 I 期临床试验;预计可将 GBM 中位生存期延长 6–9 个月。

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