Wang Xintong, An Dianzheng, Liu Xiaomeng, Wang Xinlei, Li Baosheng
Department of Radiation Oncology, Shandong Cancer Hospital Affiliated to Shandong University, Shandong University, Jinan, Shandong, People's Republic of China.
Department of Oncology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, People's Republic of China.
Onco Targets Ther. 2019 Jul 23;12:5967-5977. doi: 10.2147/OTT.S197456. eCollection 2019.
Accumulating evidence suggests that microRNAs (miRNAs) possess diverse cellular regulatory roles in radiation responses. In this study, we aimed to identify the role of miR-27a in esophageal squamous cell carcinoma (ESCC) radiosensitivity by exploring the relationship between miR-27a and heat shock protein 90 (Hsp90).
We performed quantitative real-time polymerase chain reaction (qRT-PCR) to detect miR-27a expression in the plasma of ESCC patients and healthy volunteers. The expression of Hsp90 and its key client proteins associated with radioresistance were analyzed by Western blotting. Then, the effects of miR-27a on proliferation, apoptosis, cell cycle and radiosensitivity in ESCC cell lines were determined by CCK-8, flow cytometry, and clonogenic survival assay. We also generated subcutaneous tumors to explore whether miR-27a enhanced radiosensitivity in vivo.
In our current study, we found that miR-27a expression was downregulated in the plasma of ESCC patients compared with that of healthy volunteers. Overexpression of miR-27a in ESCC cell lines caused a reduction of Hsp90 mRNA and protein. We also demonstrated that upregulation of miR-27a induced degradation of Hsp90 key client proteins associated with radioresistance. In related functional experiments, miR-27a significantly inhibited growth, increased radiation-induced apoptosis, induced cell cycle arrest in G/G phase and enhanced ESCC radiosensitivity both in vitro and in vivo.
From these findings, we concluded that miR-27a may contribute to radiosensitivity by modulating Hsp90 expression. Moreover, miR-27a-based therapy utilized to target Hsp90 could be contemplated as a compelling alternative for sensitize ESCC to radiotherapy with fewer side effects.
越来越多的证据表明，微小RNA（miRNA）在辐射反应中具有多种细胞调节作用。在本研究中，我们旨在通过探索miR-27a与热休克蛋白90（Hsp90）之间的关系，确定miR-27a在食管鳞状细胞癌（ESCC）放射敏感性中的作用。
我们进行了定量实时聚合酶链反应（qRT-PCR），以检测ESCC患者和健康志愿者血浆中miR-27a的表达。通过蛋白质印迹分析Hsp90及其与放射抗性相关的关键客户蛋白的表达。然后，通过CCK-8、流式细胞术和克隆形成存活试验，确定miR-27a对ESCC细胞系增殖、凋亡、细胞周期和放射敏感性的影响。我们还生成了皮下肿瘤，以探讨miR-27a在体内是否增强放射敏感性。
在我们目前的研究中，我们发现与健康志愿者相比，ESCC患者血浆中miR-27a的表达下调。ESCC细胞系中miR-27a的过表达导致Hsp90 mRNA和蛋白减少。我们还证明，miR-27a的上调诱导了与放射抗性相关的Hsp90关键客户蛋白的降解。在相关功能实验中，miR-27a在体外和体内均显著抑制生长、增加辐射诱导的凋亡、诱导细胞周期停滞在G/G期并增强ESCC放射敏感性。
从这些发现中，我们得出结论，miR-27a可能通过调节Hsp90表达来促进放射敏感性。此外，以Hsp90为靶点的基于miR-27a的治疗方法可被视为一种有吸引力的替代方案，用于使ESCC对放疗敏感且副作用更少。
