Fig. 2

Exogenetic expression of miR-449a suppresses hepatocellular carcinoma cell invasion in vitro and reduces metastasis in vivo. a Effect of miR-449a on colony formation of the HCC cell line. Two hundred or 500 miR-124-infected Huh7 and LM9 cells were plated and a colony formation assay carried out. Representative results of colony formation of mock, miR-control-lentivirus-infected, miR-449a-lentivirus-infected Huh7 and LM9 cells. The results were reproducible in three independent experiments. b The wound-healing assay showed different cell motilities in miR-control-LM9, miR-449a-LM9, miR-control-Huh7 and miR-449a-Huh7 cells. The ectopic expression of miR-449a obviously inhibited the migration of LM9 and Huh7 cells. c Cell invasion was evaluated using a Matrigel invasion chamber. LM9 and Huh7 cells were infected by miR-control-lentivirus and miR-449a-lentivirus, respectively. All cells were subjected to a Matrigel invasion assay with fetal bovine serum as chemoattractant. Invasive cells were fixed and stained with crystal violet. The inserts were treated with 10 % acetic acid and the absorbance was measured. Both overexpression of miR-449a clearly inhibited the invasion of LM9 and Huh7 cells. Data are the means ± SD of three independent experiments. *p < 0.05, **p < 0.01. Scale bar: 100 mm. d Up, representative liver, treatments indicated. Down, the sizes of primary tumours in livers of mice, thirty-eight days after implantation of miR-control-Huh7 cells (average size, ± SE, 6.199 ± 1.63 mm) and miR-449a-Huh7 cells (average size, ± SE, 2.50 ± 0.79 mm). e The restoration of miR-449a inhibited the pulmonary metastases of HCC cells in vivo. miR-449a-Huh7 (Huh7 cells with stable expression of miR-449a) and miR-control-Huh7(control cells) were inoculated under the capsules of the left hepatic lobes of nude mice. Hematoxylin-eosin (HE) staining was performed on the serial sections of paraffin-embedded lung tissues (left and middle panels). Scale bar, ×100