Imaging Therapies and Cancer Group, Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, King's College London, London, United Kingdom.
Department of Physics, King's College London, London, United Kingdom.
Front Immunol. 2023 Jun 8;14:1180233. doi: 10.3389/fimmu.2023.1180233. eCollection 2023.
MicroRNAs are small non-coding RNAs and represent key players in physiology and disease. Aberrant microRNA expression is central to the development and progression of cancer, with various microRNAs proposed as potential cancer biomarkers and drug targets. There is a need to better understand dynamic microRNA expression changes as cancers progress and their tumor microenvironments evolve. Therefore, spatiotemporal and non-invasive microRNA quantification in tumor models would be highly beneficial.
We developed an microRNA detector platform in which the obtained signals are positively correlated to microRNA presence, and which permitted stable expression in cancer cells as needed for long-term experimentation in tumor biology. It exploits a radionuclide-fluorescence dual-reporter for quantitative imaging of a microRNA of choice by radionuclide tomography and fluorescence-based downstream ex vivo tissue analyses. We generated and characterized breast cancer cells stably expressing various microRNA detectors and validated them .
We found the microRNA detector platform to report on microRNA presence in cells specifically and accurately, which was independently confirmed by real-time PCR and through microRNA modulation. Moreover, we established various breast tumor models in animals with different levels of residual immune systems and observed microRNA detector read-outs by imaging. Applying the detector platform to the progression of a triple-negative breast cancer model, we found that miR-155 upregulation in corresponding tumors was dependent on macrophage presence in tumors, revealing immune-mediated phenotypic changes in these tumors as they progressed.
While applied to immunooncology in this work, this multimodal microRNA detector platform will be useful whenever non-invasive quantification of spatiotemporal microRNA changes in living animals is of interest.
microRNAs 是小的非编码 RNA，是生理和疾病中的关键参与者。microRNA 表达异常是癌症发生和发展的核心，各种 microRNA 被提议作为潜在的癌症生物标志物和药物靶点。需要更好地了解癌症进展和肿瘤微环境演变过程中动态的 microRNA 表达变化。因此，肿瘤模型中时空和非侵入性的 microRNA 定量将非常有益。
我们开发了一种 microRNA 检测平台，该平台获得的信号与 microRNA 的存在呈正相关，并且在肿瘤生物学的长期实验中需要稳定表达在癌细胞中。它利用放射性核素-荧光双重报告分子，通过放射性核素断层扫描和基于荧光的体外组织分析对所选 microRNA 进行定量成像。我们生成并表征了稳定表达各种 microRNA 检测分子的乳腺癌细胞，并对其进行了验证。
我们发现 microRNA 检测平台能够特异性和准确地报告细胞中 microRNA 的存在，这一点通过实时 PCR 和 microRNA 调节得到了独立验证。此外，我们在具有不同残留免疫系统的动物中建立了各种乳腺癌模型，并通过成像观察到 microRNA 检测读数。将检测平台应用于三阴性乳腺癌模型的进展，我们发现相应肿瘤中 miR-155 的上调依赖于肿瘤中巨噬细胞的存在，揭示了这些肿瘤在进展过程中免疫介导的表型变化。
虽然本工作将该多模式 microRNA 检测平台应用于免疫肿瘤学，但无论何时需要在活体动物中对时空 microRNA 变化进行非侵入性定量，该平台都将非常有用。
