PURPOSE miR-491 functions as a tumor suppressor in several types of cancer. However, its function and mechanism in gastric cancer proliferation and metastasis have not been well defined. The aim of this study was to explore the role and regulatory mechanism of miR-491 in cell proliferation and migration in gastric cancer. METHODS Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was used to detect the expression pattern of miR-491 in gastric cancer tissues. miR-491 overexpression vector, miR-491 inhibitor, and siHMGA2 were used; and MTT, wound healing, and transwell assays were employed to examine proliferation and migration for BGC-823 cells. A dual-luciferase reporter gene was used to measure the target relationship between miR-491 and HMGA2. RESULTS Most gastric cancer patients exhibit decreased miR-491 expression. miR-491 overexpression inhibited cell proliferation and migration, whereas miR-491 inhibitor treatment produced the opposite effect. Mechanistically, HMGA2 was identified as a direct target of miR-491. Moreover, HMGA2 knockdown inhibited cell proliferation and migration, which was similar to the effect of miR-491 overexpression. HMGA2 was decreased after transfection of the miR-491 vector and increased after transfection of the miR-491 inhibitor. CONCLUSION Our results suggest that miR-491 suppressed cell proliferation and cell motility in gastric cancer by targeting HMGA2. Silencing HMGA2 produced a similar effect to miR-491 overexpression on cell proliferation and migration. miR-491/HMGA2 signaling may be a potential therapeutic target for gastric cancer patients with decreased miR-491 expression.

中文翻译：

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miR-491 通过靶向 HMGA2 抑制 BGC-823 细胞迁移。

目的 miR-491 在几种类型的癌症中充当肿瘤抑制因子。然而，其在胃癌增殖和转移中的作用和机制尚未明确。本研究旨在探讨miR-491在胃癌细胞增殖和迁移中的作用及调控机制。方法采用定量逆转录聚合酶链反应（qRT-PCR）检测胃癌组织中miR-491的表达模式。使用了miR-491过表达载体、miR-491抑制剂和siHMGA2；和 MTT、伤口愈合和 transwell 测定用于检查 BGC-823 细胞的增殖和迁移。使用双荧光素酶报告基因来测量 miR-491 和 HMGA2 之间的靶标关系。结果 大多数胃癌患者表现出 miR-491 表达降低。miR-491 过表达抑制细胞增殖和迁移，而 miR-491 抑制剂处理产生相反的效果。从机制上讲，HMGA2 被鉴定为 miR-491 的直接靶标。此外，HMGA2 敲低抑制细胞增殖和迁移，这与 miR-491 过表达的作用相似。HMGA2 在转染 miR-491 载体后减少，在转染 miR-491 抑制剂后增加。结论 我们的研究结果表明，miR-491 通过靶向 HMGA2 抑制胃癌细胞增殖和细胞运动。沉默 HMGA2 对细胞增殖和迁移产生与 miR-491 过表达类似的效果。miR-491/HMGA2 信号转导可能是 miR-491 表达降低的胃癌患者的潜在治疗靶点。