Figure 2.

Effect of miR30a on cellular proliferation, migration and invasion, apoptosis, and metastasis. A, miR30a inhibits cellular proliferation. The effect of miR30a overexpression was determined in four ATC cell lines, 8505C, THJ-11T, THJ-16T, and SW1736, using a CyQUANT Cell Proliferation Assay and a clonogenic assay after transfection with 25 nmol/L of miR30a or miR-C. miR30a transfection significantly inhibited cell proliferation and colonies formation compared with miR-C. ^*, P < 0.05; ^**, P < 0.01; ^***, P < 0.001. B, representative images of ATC cells obtained using fluorescent microscopy. Viable cells exhibit green fluorescence (calcein-AM), whereas membrane-permeable, nonviable cells exhibit red fluorescence (ethidium homodimer-1). Cells are shown 72 hours after transfection. C, ectopic expression of miR30a increased caspase-3/7 activity. Data shown are from 72 hours after transfection. ^**, P < 0.01; ^***, P < 0.001. D, miR30a inhibits cellular migration and invasion. The Transwell assay showed that overexpression of miR30a markedly decreased invasion and migration in four ATC cell lines. These results are representative of at least three independent experiments. E, ectopic expression of miR30a reduces N-cadherin, vimentin, and CD44 expression compared with miR-C. F, effect of miR30a on tumor growth and metastasis in vivo. Nude mice were injected subcutaneously with 8505C-Luc cells expressing either miR-C or miR30a. Luciferase activity (mean±SD) was measured over time in flank xenograft (left) and metastatic (right) models. There was no significant difference in growth in the flank xenograft, but there was a significant difference in the number and volume of metastatic lesions in mice that had tail-vein injections of 8505C-Luc cells. Luciferase activity images of lung metastases in mice that received tail-vein injection of cells overexpressing miR30a (3 mice) or miR-C (3 mice). RFU, relative fluorescence unit. ^*, P < 0.05; ^**, P < 0.01; ^***, P < 0.001.