Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, 301 Middle Yanchang Road, Shanghai, 200072, China.
Int J Med Sci. 2020 Jun 5;17(10):1415-1427. doi: 10.7150/ijms.41980. eCollection 2020.
: Doxorubicin (DOX) is one of the widely used anti-cancer drugs, whereas it can induce irreversible cardiac injury in a dose-dependent manner which limits its utility in clinic. Our study aimed to investigate the relationship between miR-25 and DOX-induced cardiac injury and its underlying mechanism. : Mice and H9c2 cells were exposed to DOX. The overexpressed or knockdown of miR-25 in H9c2 cells was achieved by miR-25 mimic or inhibitor and the efficiency of transfection was identified by qRT-PCR or Western blotting. Cell viability, apoptotic cell rate, and levels of apoptosis-related proteins were determined by CCK-8, flow cytometry, and Western blotting, respectively. Furthermore, Western blotting and immunofluorescence staining (IF) were performed to assess the expression levels of reactive oxygen species and degree of DNA damage. : As a result, DOX significantly upregulated miR-25 expression in mice and H9c2 cells and reduced cell viability and increased cell apoptosis and . miR-25 overexpression expedited cell injury induced by DOX in H9c2 cells demonstrated by the increased cell apoptosis and reactive oxygen species (ROS) production, whereas miR-25 inhibition attenuated the cell injury. Furthermore, miR-25 negatively controlled the expression of phosphatase and tensin homolog deleted on chromosome 10 (PTEN). Intervention the expression of PTEN using si-PTEN reversed the beneficial effects of miR-25 inhibition on DOX-injured H9c2 cells. : In conclusion, this study demonstrated that miR-25 is involved in DOX-induced cell damage through the regulation of PTEN expression.
多柔比星（DOX）是一种广泛应用的抗癌药物，但它会导致剂量依赖性的不可逆心脏损伤，从而限制了其在临床中的应用。本研究旨在探讨 miR-25 与 DOX 诱导的心脏损伤之间的关系及其潜在机制。
将小鼠和 H9c2 细胞暴露于 DOX 中。通过 miR-25 模拟物或抑制剂实现 H9c2 细胞中 miR-25 的过表达或敲低，并通过 qRT-PCR 或 Western blot 鉴定转染效率。通过 CCK-8、流式细胞术和 Western blot 分别测定细胞活力、凋亡细胞率和凋亡相关蛋白水平。此外，通过 Western blot 和免疫荧光染色（IF）评估活性氧（ROS）水平和 DNA 损伤程度。
结果，DOX 显著上调了小鼠和 H9c2 细胞中的 miR-25 表达，并降低了细胞活力，增加了细胞凋亡。miR-25 过表达加速了 DOX 诱导的 H9c2 细胞损伤，表现为细胞凋亡和 ROS 产生增加，而 miR-25 抑制则减轻了细胞损伤。此外，miR-25 负调控磷酸酶和张力蛋白同源物缺失的染色体 10（PTEN）的表达。使用 si-PTEN 干预 PTEN 的表达逆转了 miR-25 抑制对 DOX 损伤的 H9c2 细胞的有益作用。
综上所述，本研究表明，miR-25 通过调节 PTEN 的表达参与 DOX 诱导的细胞损伤。
