Shanghai Key Laboratory of Gastric Neoplasms, Department of Surgery, Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Rui Jin Road, Shanghai 200025, People's Republic of China.
BMC Cancer. 2014 Jan 21;14:34. doi: 10.1186/1471-2407-14-34.
Emerging evidence has shown that microRNAs are involved in gastric cancer development and progression. Here we examine the role of miR-133b in gastric cancer.
Quantitative real-time PCR analysis was performed in 140 patient gastric cancer tissues and 8 gastric cancer cell lines. The effects of miR-133b in gastric cancer cells metastasis were examined by scratch assay, transwell migration and matrigel invasion. In vivo effects of miR-133b were examined in an intraperitoneal mouse tumor model. Targets of miR-133b were predicted by bioinformatics tools and validated by luciferase reporter analyses, western blot, and quantitative real-time PCR.
MiR-133b was significantly downregulated in 70% (98/140) of gastric cancer patients. Expression of miR-133b was negatively correlated with lymph node metastasis of gastric cancer in patients. Similarly, the expression of miR-133b was significantly lower in seven tested gastric cancer cell lines than in the immortalized non-cancerous GES-1 gastric epithelial cells. Overexpression of miR-133b markedly inhibited metastasis of gastric cancer cells in vitro and in vivo. Moreover, the transcriptional factor Gli1 was identified as a direct target for miR-133b. Level of Gli1 protein but not mRNA was decreased by miR-133b. Activity of luciferase with Gli1 3'-untranslated region was markedly decreased by miR-133b in gastric cancer cells. Gli1 target genes, OPN and Zeb2, were also inhibited by miR133b.
MiR-133b is frequently decreased in gastric cancer. Overexpression of miR-133b inhibits cell metastasis in vitro and in vivo partly by directly suppressing expression of Gli1 protein. These results suggested that miR-133b plays an important role in gastric cancer metastasis.
新出现的证据表明，miRNAs 参与了胃癌的发生和发展。在这里，我们研究了 miR-133b 在胃癌中的作用。
在 140 例胃癌患者组织和 8 种胃癌细胞系中进行了定量实时 PCR 分析。通过划痕试验、Transwell 迁移和 Matrigel 侵袭试验检测 miR-133b 在胃癌细胞转移中的作用。在腹腔小鼠肿瘤模型中检测 miR-133b 的体内作用。通过生物信息学工具预测 miR-133b 的靶标，并通过荧光素酶报告分析、Western blot 和定量实时 PCR 进行验证。
miR-133b 在 70%（98/140）的胃癌患者中显著下调。miR-133b 的表达与胃癌患者的淋巴结转移呈负相关。同样，在七种测试的胃癌细胞系中，miR-133b 的表达明显低于永生化非癌性 GES-1 胃上皮细胞。miR-133b 的过表达显著抑制了胃癌细胞的体外和体内转移。此外，转录因子 Gli1 被鉴定为 miR-133b 的直接靶标。miR-133b 降低了 Gli1 蛋白而不是 mRNA 的水平。miR-133b 显著降低了胃癌细胞中Gli1 3'-非翻译区的荧光素酶活性。Gli1 靶基因 OPN 和 Zeb2 也被 miR133b 抑制。
miR-133b 在胃癌中经常下调。miR-133b 的过表达在体外和体内均抑制细胞转移，部分原因是直接抑制 Gli1 蛋白的表达。这些结果表明，miR-133b 在胃癌转移中发挥重要作用。
