Du Jiang, Zhong Hong, Ma Binlin
Department of Breast and Thyroid Surgery, The 3rd Affiliated Teaching Hospital of Xinjiang Medical University (Affiliated Cancer Hospital), Suzhou East Street No. 789, Xinshi District, Urumqi, 830011, Xinjiang, China.
Cancer Cell Int. 2021 Mar 31;21(1):186. doi: 10.1186/s12935-021-01885-0.
To our knowledge, LncRNA SNHG15 exerted its tumor-promoting effects to facilitate the development of breast cancer (BC), but there still needed more data to elucidate the potential underlying mechanisms.
We examined genes expression status by performing Real-Time qPCR and Western Blot analysis, and cellular functions, including cell proliferation, viability, apoptosis, mobility, were measured by using the CCK-8 assay, colony formation assay, trypan blue staining assay, flow cytometer (FCM), transwell assay and wound scratch assay, respectively. The predicted targeting sites in LncRNA SNHG15, miR-451 and c-Myc 3'UTR were validated by dual-luciferase reporter gene system assay. Finally, we established the tumor-bearing mice models, and the expression status, including its enrichment and cellular localization were examined by immunohistochemistry (IHC) assay.
Our data indicated LncRNA SNHG15 upregulated c-Myc to facilitate BC progression by sponging miR-451 in a competing endogenous RNA (ceRNA)-dependent manner in vitro and in vivo. Specifically, LncRNA SNHG15 and c-Myc were upregulated, while miR-451 was downregulated in BC cells and clinical tissues, compared to their normal counterparts. In addition, miR-451 negatively correlated with LncRNA SNHG15 and c-Myc, and LncRNA SNHG15 was positively relevant to c-Myc in BC tissues. Next, we validated that LncRNA SNHG15 sponged miR-451 to upregulate c-Myc in BC cells. Further gain- and loss-of-function experiments evidenced that LncRNA SNHG15 promoted, while miR-451 inhibited malignant phenotypes, including cell proliferation, viability, migration, invasion and epithelial-mesenchymal transition (EMT) in BC cells. Interestingly, the inhibiting effects of LncRNA SNHG15 ablation on BC progression were abrogated by both silencing miR-451 and overexpressing c-Myc.
We concluded that targeting the LncRNA SNHG15/miR-451/c-Myc signaling cascade was novel to hamper BC progression, which broadened our knowledge in this field, and provided potential biomarkers for BC diagnosis and treatment.
据我们所知，长链非编码RNA SNHG15发挥其促肿瘤作用以促进乳腺癌（BC）的发展，但仍需要更多数据来阐明潜在的机制。
我们通过实时定量聚合酶链反应（Real-Time qPCR）和蛋白质免疫印迹分析检测基因表达状态，并分别使用细胞计数试剂盒-8（CCK-8）检测法、集落形成检测法、台盼蓝染色检测法、流式细胞仪（FCM）、Transwell检测法和划痕实验检测细胞功能，包括细胞增殖、活力、凋亡、迁移能力。通过双荧光素酶报告基因系统检测法验证长链非编码RNA SNHG15、miR-451和c-Myc 3'非翻译区（UTR）中的预测靶向位点。最后，我们建立了荷瘤小鼠模型，并通过免疫组织化学（IHC）检测法检测其表达状态，包括其富集情况和细胞定位。
我们的数据表明，长链非编码RNA SNHG15在体外和体内通过以竞争性内源RNA（ceRNA）依赖的方式吸附miR-451来上调c-Myc，从而促进BC进展。具体而言，与正常对照相比，BC细胞和临床组织中长链非编码RNA SNHG15和c-Myc上调，而miR-451下调。此外，在BC组织中，miR-451与长链非编码RNA SNHG15和c-Myc呈负相关，长链非编码RNA SNHG15与c-Myc呈正相关。接下来，我们验证了长链非编码RNA SNHG15在BC细胞中吸附miR-451以上调c-Myc。进一步的功能获得和丧失实验证明，长链非编码RNA SNHG15促进，而miR-451抑制BC细胞中的恶性表型，包括细胞增殖、活力、迁移、侵袭和上皮-间质转化（EMT）。有趣的是，沉默miR-451和过表达c-Myc均消除了长链非编码RNA SNHG15缺失对BC进展的抑制作用。
我们得出结论，靶向长链非编码RNA SNHG15/miR-451/c-Myc信号级联对于阻碍BC进展是新的发现，这拓宽了我们在该领域的知识，并为BC的诊断和治疗提供了潜在的生物标志物。
