Expression of miR-101-3p in Gastric Cancer and Its Effects on Invasion, Metastasis, and Angiogenesis of Gastric Cancer Cells by Targeting STC-1 Gene to Regulate PI3K/AKT Signaling Pathway / 肿瘤防治研究

ABSTRACT

Objective To explore the expression of miR-101-3p in gastric cancer and its mechanism on the invasion, metastasis, and angiogenesis of gastric cancer cells by targeting the STC-1 gene to regulate the PI3K/AKT signaling pathway. Methods qRT-PCR was used to detect the expression of miR-101-3p and STC-1 mRNA in gastric cancer tissues and BGC-823 cell and analyze the relationship between miR-101-3p expression and patients' clinical pathological factors. The cells were transfected with miRNA mimics and plasmids separately or in combination with LipofectamineTM 2000. TargetScanHuman prediction and dual-luciferase assay were used to verify the targeted regulation of miR-101-3p on STC-1. The effect and possible mechanism of miR-101-3p targeting the STC-1 gene on the invasion, metastasis, and angiogenesis of cancer cells were verified by scratch test, Transwell chamber test, Matrigel in vitro tube forming test, and Western blot assay. The development of the transplanted tumor was detected by nude mouse tumorigenicity test. Results The expression of STC-1 in gastric cancer tissues was higher than that in normal tissues. Compared with normal gastric tissues and GES-1 cells, miR-101-3p was down-regulated, and STC-1 mRNA was up-regulated in gastric cancer tissues and BGC-823 cell. The level of miR-101-3p was negatively correlated with the level of STC-1, and significantly correlated with the degree of tumor differentiation, TNM stage, and lymph node metastasis (P < 0.05). miR-101-3p directly targeted STC-1. The overexpression of miR-101-3p inhibited STC-1 expression and downregulated the expression of p-PI3K/PI3K, p-AKT/AKT, MMP-2, MMP-9, VEGF, and Ang2, consequently, inhibited tumor cell invasion, metastasis, and angiogenesis and reduced the size and weight of the transplanted tumors (P < 0.05). Conclusion miR-101-3p is down-regulated in gastric cancer and can target the STC-1 gene to regulate the PI3K/AKT signaling pathway and inhibit the invasion, metastasis, and angiogenesis of BGC-823 gastric cancer cells and the development of transplanted tumors in vivo.