MicroRNA-331 inhibits development of gastric cancer through targeting musashi1

Figure 1 Downregulation of miR-331 associated with prognosis was detected in gastric cancer. A: The mRNA expression of miR-331 was examined in gafstric cancer (GC) tissues. B: MiR-331 expression was determined in MKN-45, MGC-803, SGC-7901, and GES1 cells. C and D: Low miR-331expression was correlated with shorter DFS and OS time in GC patients. ^aP < 0.05, ^bP < 0.01.

Figure 2 MiR-331 inhibited gastric cancer cell viability in vitro and vivo. A: MiR-331 mRNA expressions was determined in MKN-45 cells with miR-331 mimic or inhibitor. B: Cell proliferation was regulated by miR-331 mimic or inhibitor in MKN-45 cells. C: Photographs of gastric cancer (GC) tumors in miR-NC (n = 5) or miR-331 mimics (n = 5) group. Ten mice were used for xenograft tumor formation assay. Here are five of the results. D: In nude mice with miR-NC or miR-331 mimics, GC tumor volume was measured every week. E: Ki-67-stained sections of transplanted tumors in miR-NC or miR-331 mimics group. ^aP < 0.05, ^bP < 0.01.

Figure 3 MiR-331 inhibited cell metastasis in gastric cancer. A-C: MKN-45 cell migration and invasion were regulated by miR-331 mimic or inhibitor. D: MiR-331 regulated expressions of E-cadherin, N-cadherin and Vimentin in MKN-45 cells. ^aP < 0.05, ^bP < 0.01.

Figure 4 MiR-331 directly targets musashi1. A: There are binding sites between musashi1 (MSI1) with miR-331. B: Luciferase reporter assay (C, D) MSI1 expression regulated by miR-331 mimics or inhibitor was observed in MKN-45 cells. ^aP < 0.05, ^bP < 0.01.

Figure 5 Musashi1 upregulation weakened miR-331 inhibitory effect in gastric cancer. A: Musashi1 (MSI1) expression was detected in gastric cancer (GC) tissues. B: MiR-331 negatively regulated MSI1 expression in GC tissues. C and D: The mRNA and protein MSI1 expressions were detected in MKN-45 cells containing MSI1 vector and miR-331 mimic. E: Cell proliferation was identified in MKN-45 cells containing MSI1 vector and miR-331 mimic. F: Protein expressions of E-cadherin, N-cadherin and Vimentin in MKN-45 cells with MSI1 vector and miR-331 mimic (G) Cell migration and invasion were identified in MKN-45 cells containing MSI1 vector and miR-331 mimic. ^bP < 0.01.