Department of Respiratory Medicine, the First Affiliated Hospital of Soochow University, Suzhou, 215006, China.
Suzhou Key Laboratory for Respiratory Diseases, Suzhou, 215006, China.
J Exp Clin Cancer Res. 2020 May 11;39(1):84. doi: 10.1186/s13046-020-01585-z.
The Ecotropic viral integration site 5 (EVI5), an important protein in regulating cell cycle, cytokinesis and cellular membrane traffic, functions as a stabilizing factor maintaining anaphase-promoting complex/cyclosome (APC/C) inhibitor Emi1 in S/G2 phase. However, the mechanism by which EVI5 promotes malignant transformation of non-small cell lung cancer (NSCLC) remains unknown. In the present study, we addressed the role of EVI5 in NSCLC by regulating tumor growth, migration and invasion.
The expression levels of EVI5 and miR-486-5p in NSCLC tissues and cells were measured by real-time PCR. Meanwhile, EVI5 and its associated protein expression were analyzed by western blot and co-immunoprecipitation assay. Flow cytometry was performed to determine cell proliferation and apoptosis. CCK-8 and clonogenic assays were used to analyze cell viability. Wound healing, transwell migration and matrigel invasion assays were utilized to assess the motility of tumor cells. To investigate the role of EVI5 in vivo, lung carcinoma xenograft mouse model was applied..
EVI5 was upregulated in NSCLC tissues and cell lines when compared with that in normal tissues and cell line. Knockdown of EVI5 in vitro inhibited tumor cell proliferation, migration and invasion in NSCLC cells. Further, inoculation of EVI5-deficient tumor cells into nude mice suppressed tumor proliferation and metastasis compared to control mice inoculated with unmanipulated tumor cells. These data indicated that EVI5 promote the proliferation of NSCLC cells which was consistent with our previous results. Additionally, we showed that EVI5 was directly regulated by miR-486-5p, and miR-486-5p-EVI5 axis affected the NSCLC migration and invasion through TGF-β/Smad signaling pathway by interacting with TGF-β receptor II and TGF-β receptor I.
Based on these results, we demonstrated a new post-transcriptional mechanism of EVI5 regulation via miR-486-5p and the protumoral function of EVI5 in NSCLC by interacting with Emi1 and/or TGF-β receptors, which provides a new insight into the targeted therapy of NSCLC.
嗜同性病毒整合位点 5（EVI5）是调节细胞周期、胞质分裂和细胞膜运输的重要蛋白，作为稳定因子发挥作用，维持有丝分裂促进复合物/周期蛋白体（APC/C）抑制剂 Emi1 在 S/G2 期。然而，EVI5 促进非小细胞肺癌（NSCLC）恶性转化的机制尚不清楚。在本研究中，我们通过调节肿瘤生长、迁移和侵袭来研究 EVI5 在 NSCLC 中的作用。
通过实时 PCR 测量 NSCLC 组织和细胞中 EVI5 和 miR-486-5p 的表达水平。同时，通过 Western blot 和免疫共沉淀分析检测 EVI5 及其相关蛋白的表达。通过流式细胞术测定细胞增殖和凋亡。CCK-8 和集落形成实验用于分析细胞活力。划痕愈合、Transwell 迁移和 Matrigel 侵袭实验用于评估肿瘤细胞的迁移能力。为了研究 EVI5 在体内的作用，应用了肺癌异种移植小鼠模型。
与正常组织和细胞系相比，EVI5 在 NSCLC 组织和细胞系中上调。体外敲低 EVI5 抑制 NSCLC 细胞的肿瘤细胞增殖、迁移和侵袭。此外，与接种未处理的肿瘤细胞的对照小鼠相比，接种缺乏 EVI5 的肿瘤细胞的裸鼠抑制了肿瘤的增殖和转移。这些数据表明，EVI5 促进了 NSCLC 细胞的增殖，这与我们之前的结果一致。此外，我们表明 EVI5 被 miR-486-5p 直接调节，并且 miR-486-5p-EVI5 轴通过与 TGF-β 受体 II 和 TGF-β 受体 I 相互作用，通过 TGF-β/Smad 信号通路影响 NSCLC 的迁移和侵袭。
基于这些结果，我们通过 miR-486-5p 证明了 EVI5 调节的新的转录后机制，以及通过与 Emi1 和/或 TGF-β 受体相互作用，EVI5 在 NSCLC 中的原癌功能，为 NSCLC 的靶向治疗提供了新的见解。
