Ye Junfeng, Zhang Ruoyan, Du Xiaohong, Chai Wengang, Zhou Qiang
Department of Hepato-Biliary-Pancreatic Surgery, The First Hospital of Jilin University, Changchun City, Jilin Province, PR China.
Department of Hepatology, The First Hospital of Jilin University, Changchun City, Jilin Province, PR China,
Onco Targets Ther. 2019 Jan 4;12:415-422. doi: 10.2147/OTT.S175176. eCollection 2019.
Sorafenib is widely used for treatment of hepatocellular carcinoma (HCC), but the acquired resistance remains a major obstacle for its application. Thus it is of critical importance to elucidate the molecular mechanisms underlying sorafenib resistance in HCC. This study aimed to determine the roles of long noncoding RNA SNHG16 in sorafenib-resistant HCC cells.
HCC and matched adjacent normal liver tissue samples were obtained from 103 HCC patients. Sorafenib-resistant HepG2/SOR cell line was established from its parental HepG2 cells by exposure to increasing concentrations of sorafenib. SNHG16 and miR-140-5p expression levels in tissue samples and cells were detected by RT-qPCR analysis. The sensitivity of cells to sorafenib in vitro was evaluated by MTT assay, and the sensitivity of HepG2/SOR cells to sorafenib in vivo was estimated using the nude mouse-based xenograft model. The potential binding relation between SNHG16 and miR-140-5p was validated by dual luciferase reporter assay and biotinylated RNA pull-down assay.
The results showed that SNHG16 expression was remarkably increased in HCC tissues and cell lines, and its high expression was closely associated with aggressive clinicopathological features and poor prognosis of HCC patients. Further experiments showed that SNHG16 is upregulated in HepG2/SOR cells, whereas knockdown of SNHG16 increases the sensitivity of HepG2/SOR cells to sorafenib in vitro and in vivo. Further mechanistic study identified that SNHG16 functions as an endogenous sponge for miR-140-5p in HepG2 cells, and in HCC tissues, the expression of miR-140-5p is negatively correlated with SNHG16 expression. Moreover, miR-140-5p overexpression also increases the sensitivity of HepG2/SOR cells to sorafenib, and the effects of SNHG16 knockdown on sorafenib resistance could be blocked by miR-140-5p inhibitor.
Collectively, our findings demonstrated that knockdown of SNHG16 attenuated sorafenib resistance in HCC through sponging miR-140-5p, indicating that SNHG16 might be as a promising therapeutic target to boost the effectiveness of chemotherapy for HCC patients.
索拉非尼被广泛用于治疗肝细胞癌（HCC），但其获得性耐药仍然是其应用的主要障碍。因此，阐明HCC中索拉非尼耐药的分子机制至关重要。本研究旨在确定长链非编码RNA SNHG16在索拉非尼耐药HCC细胞中的作用。
从103例HCC患者中获取HCC及配对的癌旁正常肝组织样本。通过暴露于浓度递增的索拉非尼，从其亲本HepG2细胞建立索拉非尼耐药的HepG2/SOR细胞系。通过RT-qPCR分析检测组织样本和细胞中SNHG16和miR-140-5p的表达水平。通过MTT法评估细胞对索拉非尼的体外敏感性，并使用基于裸鼠的异种移植模型评估HepG2/SOR细胞对索拉非尼的体内敏感性。通过双荧光素酶报告基因检测和生物素化RNA下拉检测验证SNHG16与miR-140-5p之间的潜在结合关系。
结果显示，SNHG16在HCC组织和细胞系中表达显著增加，其高表达与HCC患者侵袭性临床病理特征及不良预后密切相关。进一步实验表明，HepG2/SOR细胞中SNHG16上调，而敲低SNHG16可增加HepG2/SOR细胞在体外和体内对索拉非尼的敏感性。进一步的机制研究发现，SNHG16在HepG2细胞中作为miR-140-5p的内源性海绵发挥作用，且在HCC组织中，miR-140-5p的表达与SNHG16表达呈负相关。此外，miR-140-5p过表达也增加了HepG2/SOR细胞对索拉非尼的敏感性，且miR-140-5p抑制剂可阻断敲低SNHG16对索拉非尼耐药的影响。
总体而言，我们的研究结果表明，敲低SNHG16通过吸附miR-140-5p减轻了HCC中的索拉非尼耐药，表明SNHG16可能是提高HCC患者化疗疗效的一个有前景的治疗靶点。
