长非编码RNA HOTAIR调控胃癌细胞SGC-7901来源肿瘤干细胞样细胞

肿瘤干细胞样细胞具有自我更新、无限增殖和多向分化能力，且受到长非编码RNA（long non-coding RNAs, lncRNAs）的调控。长非编码RNA HOTAIR在人胃癌细胞中表达升高，且具有调控功能。但目前对其在胃癌干细胞样细胞中的功能尚无研究。本研究的目的是探讨胃癌肿瘤干细胞中HOTAIR对肿瘤恶性行为的调控作用。本研究采用无血清培养基在补充细胞因子条件下培养SGC-7901细胞，获得悬浮生长的肿瘤干细胞样细胞微球，检测微球细胞的表面特征因子CD44、CD24及HOTAIR的表达量变化；并通过CCK-8、流式细胞分析及ELISA等技术探讨了HOTAIR对肿瘤干细胞样细胞功能调控作用。结果表明，无血清培养基中获得的肿瘤干细胞样细胞具有自我更新能力，其可连续传代细胞微球的比率为4.75%±0.76%；RT-qPCR检测显示，相对于SGC-7901细胞，肿瘤干细胞样细胞中的HOTAIR表达量明显升高；通过慢病毒干扰技术发现，HOTAIR干扰抑制了HLA-G蛋白分泌、促进肿瘤干细胞样细胞的细胞周期推进、细胞增殖和自我更新能力维持。本研究提示，胃癌细胞系SGC-7901中的肿瘤干细胞样细胞中HOTAIR表达量升高，并可能通过促进肿瘤干细胞样细胞干性调控肿瘤恶性行为。

The Long Non-Coding RNA HOTAIR Regulates Cancer Stem-Like Cells Isolated from Gastric Cancer SGC-7901 Cells

Cancer stem-like cells (CSCs) are characterized by their capacity of self-renewal, proliferation and differentiation, which is tightly regulated by long non-coding RNAs (lncRNAs). HOTAIR is upregulated in gastric cancer cells and exerts regulatory roles. However, the function of HOTAIR in CSCs derived from gastric cancer is still unknown. Here we aim to study the potential regulatory effects of HOTAIR on malignant behaviors of CSCs isolated from gastric cancer. First we isolated CSCs spheres by incubating SGC-7901 cells in the serum-free medium (SFM). The CSCs shows self-renewal capacity and the sphere-forming rate is about 4.75%±0.76%. Then we performed semiquantitative-Western blotting and detected the biomarker for CSCs-CD24 and CD44. Next, RT-qPCR results demonstrated that HOTAIR was significantly upregulated in CSCs compared with SGC-7901. We also utilized lentivirus-packed shRNA targeting HOTAIR and observed that the expression of HLA-G was inhibited. Finally, the CCK-8 assay, flow cytometry and ELISA assay demonstrated that HOTAIR knockdown promoted cell cycle entry, proliferation and self-renewal capacity. Taken together, CSCs isolated from SGC-7901 cells upregulated HOTAIR levels, which is positively associated with the malignant behaviors of CSCs.