Department of Gastroenterology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, No 100, Haining Rd, Shanghai, 200080, China.
J Exp Clin Cancer Res. 2021 Jan 9;40(1):26. doi: 10.1186/s13046-020-01825-2.
Increasing evidence has demonstrated that long noncoding RNAs (lncRNAs) have regulatory functions in hepatocellular carcinoma (HCC). The link between lincSCRG1 and HCC remains unclear.
To explore the lincSCRG1 regulation axis, bioinformatics, RIP and luciferase reporter assay were performed. The expressions of lincSCRG1-miR26a-SKP2 were detected in HCC tissues and cell lines through qPCR and western blot. The functions of HCC cells were investigated through in vitro assays (MTT, colony formation, transwell and flow cytometry) and the inner effect of lincSCRG1-miR26a in vivo was evaluated by xenografts and liver metatstatic nude mice models.
LincSCRG1 was found to be strongly elevated in human HCC tissues and cell lines. MiR26a and S phase kinase-related protein 2 (SKP2) were predicted as the target miRNA for lincSCRG1 and the target gene for miR26a with direct binding sites, respectively. LincSCRG1 was verified as a competing endogenous RNA (ceRNA) via negative regulation of miR26a and derepression of SKP2 in HCC cells. Both overexpression of lincSCRG1 (ov-lincSCRG1) and inhibition of miR26a (in-miR26a) obviously stimulated cellular viability, colony formation, migration and proliferation of S phase cells and also significantly increased the protein levels of cyclinD1, CDK4, MMP2/3/9, Vimentin, and N-cadherin or inhibited the protein level of E-cadherin of HCC cells, while knockdown of lincSCRG1 (sh-lincSCRG1) and upregulation of miR26a (mi-miR26a) had the opposite effects on HCC cells. Cotransfection of in-miR26a or overexpression of SKP2 (ov-SKP2) with sh-lincSCRG1 could rescue the anticancer functions of sh-lincSCRG1, including suppressing proliferation and migration of HCC cells. Additionally, sh-lincSCRG1 could effectively inhibit the growth of subcutaneous xenograft tumours and lung metastasis, while the anticancer effect of sh-lincSCRG1 could be reversed by cotransfection of in-miR26a.
LincSCRG1 acts as a ceRNA of miR26a to restrict its ability to derepress SKP2, thereby inducing the proliferation and migration of HCC cells in vitro and in vivo. Depletion of lincSCRG1 could be used as a potential therapeutic approach in HCC.
越来越多的证据表明，长链非编码 RNA（lncRNA）在肝细胞癌（HCC）中具有调节功能。lincSCRG1 与 HCC 之间的联系尚不清楚。
为了探讨 lincSCRG1 的调控轴，我们进行了生物信息学、RIP 和荧光素酶报告基因检测。通过 qPCR 和 Western blot 检测 HCC 组织和细胞系中 lincSCRG1-miR26a-SKP2 的表达。通过体外实验（MTT、集落形成、transwell 和流式细胞术）研究 HCC 细胞的功能，并通过异种移植和肝转移裸鼠模型评估 lincSCRG1-miR26a 的内在作用。
我们发现 lincSCRG1 在人 HCC 组织和细胞系中强烈上调。miR26a 和 S 期激酶相关蛋白 2（SKP2）分别被预测为 lincSCRG1 的靶 miRNA 和 miR26a 的靶基因，具有直接结合位点。通过负调控 miR26a 和去抑制 HCC 细胞中的 SKP2，lincSCRG1 被证实为一种竞争性内源 RNA（ceRNA）。过表达 lincSCRG1（ov-lincSCRG1）和抑制 miR26a（in-miR26a）均明显刺激 HCC 细胞的活力、集落形成、迁移和 S 期细胞增殖，并显著增加 HCC 细胞中细胞周期蛋白 D1、CDK4、MMP2/3/9、波形蛋白和 N-钙黏蛋白的蛋白水平，或抑制 E-钙黏蛋白的蛋白水平，而敲低 lincSCRG1（sh-lincSCRG1）和上调 miR26a（mi-miR26a）对 HCC 细胞则有相反的作用。与 sh-lincSCRG1 共转染 in-miR26a 或过表达 SKP2（ov-SKP2）可挽救 sh-lincSCRG1 的抗癌作用，包括抑制 HCC 细胞的增殖和迁移。此外，sh-lincSCRG1 可有效抑制皮下异种移植瘤和肺转移的生长，而过表达 miR26a 可逆转 sh-lincSCRG1 的抗癌作用。
lincSCRG1 作为 miR26a 的 ceRNA 发挥作用，限制其去抑制 SKP2 的能力，从而在体外和体内诱导 HCC 细胞的增殖和迁移。耗竭 lincSCRG1 可作为 HCC 的一种潜在治疗方法。
