Department of Oral and Maxillofacial Surgery, Ehime University Graduate School of Medicine, Toon, Japan.
Cancer Sci. 2020 May;111(5):1645-1651. doi: 10.1111/cas.14359. Epub 2020 Mar 18.
MicroRNAs (miRNAs) can act not only as tumor suppressor genes but also as oncogenes. Oncogenic miRNAs (oncomiRs) could therefore provide opportunities for the treatment of human malignancies. Here, we aimed to identify oncomiRs present in oral squamous cell carcinoma (OSCC) and addressed whether targeting these miRNAs might be useful in treatment for cancer. Functional screening for oncomiRs in a human OSCC cell line (GFP-SAS) was carried out using the miRCURY LNA microRNA Knockdown Library - Human version 12.0. We identified a locked nucleic acid (LNA)/DNA antisense oligonucleotide against miR-361-3p (LNA-miR-361-3p) which showed the largest degree of growth inhibition of GFP-SAS cells. Transfection with a synthetic mimic of mature miR-361-3p resulted in an approximately 20% increase in the growth of GFP-SAS cells. We identified odd-skipped related 2 (OSR2) as a miR-361-3p target gene. Transfection of GFP-SAS cells with LNA-miR-361-3p caused a significant increase in the expression levels of OSR2. Cotransfection of a OSR2 3'-UTR luciferase reporter plasmid and LNA-miR-361-3p into GFP-SAS cells produced higher levels of luciferase activity than in cells cotransfected with the LNA-nontarget. We assessed the effect of LNA-miR-361-3p on the in vivo growth of GFP-SAS cells. We found that LNA-miR-361-3p significantly reduced the size of s.c. xenografted GFP-SAS tumors, compared to the control group treated with LNA-NT. Finally, we observed that miR-361-3p is overexpressed in OSCC tissues. These results suggest that miR-361-3p supports the growth of human OSCC cells both in vitro and in vivo and that targeting miR-361-3p could be a useful therapeutic approach for patients with OSCC.
微小 RNA（miRNA）不仅可以作为肿瘤抑制基因，也可以作为癌基因。因此，致癌 miRNA（oncomiR）可能为人类恶性肿瘤的治疗提供机会。在这里，我们旨在鉴定口腔鳞状细胞癌（OSCC）中存在的 oncomiR，并探讨针对这些 miRNA 是否可能对癌症治疗有用。使用 mirCURY LNA microRNA Knockdown Library - Human version 12.0 在人 OSCC 细胞系（GFP-SAS）中进行了 oncomiR 的功能筛选。我们鉴定了针对 miR-361-3p 的锁定核酸（LNA）/DNA 反义寡核苷酸（LNA-miR-361-3p），其对 GFP-SAS 细胞的生长抑制程度最大。转染成熟 miR-361-3p 的合成模拟物可使 GFP-SAS 细胞的生长增加约 20%。我们鉴定出 odd-skipped related 2（OSR2）是 miR-361-3p 的靶基因。转染 GFP-SAS 细胞的 LNA-miR-361-3p 导致 OSR2 的表达水平显著增加。将 OSR2 3'-UTR 荧光素酶报告质粒与 LNA-miR-361-3p 共转染 GFP-SAS 细胞产生的荧光素酶活性比共转染 LNA-非靶细胞更高。我们评估了 LNA-miR-361-3p 对 GFP-SAS 细胞体内生长的影响。我们发现，与用 LNA-NT 处理的对照组相比，LNA-miR-361-3p 显著降低了 GFP-SAS 皮下移植瘤的大小。最后，我们观察到 miR-361-3p 在 OSCC 组织中过表达。这些结果表明，miR-361-3p 支持体外和体内人 OSCC 细胞的生长，针对 miR-361-3p 可能是 OSCC 患者的一种有用的治疗方法。
