Fig. 5: Inhibition of dysplastic behaviors of Meta4 organoids by MEK inhibition.

a–d Inhibitory effect of Selumetinib treatment in soft agar culture for 2 weeks. a Phase contrast images show that colony formation was diminished by the treatment with Selumetinib (1 μM). Scale bars indicate 2 mm. b Colony diameter histogram shows the distribution of colony sizes. Mean value of diameters; DMSO vehicle treated Meta4 = 150.13 ± 47.2 μm and Selumetinib treated Meta4 = 133.13 ± 41.8 μm. c Graph shows a decrease in the number of colonies by Selumetinib treatment. Colonies over 100 μm in size were counted using a Gelcounter. Data are presented as mean values with standard deviation (n = 9). P-values were calculated using two-tailed Welch’s test. *P = 0.04. d Paraffin embedded sections of Meta4 organoids treated with either DMSO vehicle or Selumetinib at 2 weeks after in soft agar culture were examined by H&E staining. Scale bars indicate 20 μm. e Immunostaining for Cortactin (red) and an apical membrane marker, phospho-Ezrin (pEzrin, green) in Meta4 organoids at 10 or 28 days after 3D culture in Matrigel, or Meta4 treated with either DMSO vehicle or Selumetinib (1 μM) for 3 days. Nuclei were counterstained with DAPI (blue). Dotted boxes indicate enlarged area. Scale bars indicate 100 μm. f Immunostaining for Cortactin (red) and apical membrane markers, F-actin (blue) and pEzrin (green) in 2D monolayer cultured Meta4 treated with either DMSO vehicle or Selumetinib (1 μM) for 3 days. Nuclei were counterstained with DAPI (gray). Arrows indicate lamellipodia and dotted boxes indicate enlarged area. Scale bars indicate 20 μm. Source data are provided as a Source Data file.