D.H., Jung Y.J., Bae J.-H., Kim Y.K., Shin H.-C., Jeung Supplementary Material for: HER2 Regulates Cancer Stem Cell Activities via the Wnt Signaling Pathway in Gastric Cancer Cells <b><i>Introduction:</i></b> Human epidermal growth factor 2 (<i>HER2</i>) gene overexpression in breast carcinoma cell lines has been shown to drive mammary carcinogenesis and tumor growth and invasion through its effects on mammary stem cells. <b><i>Objective:</i></b> Therefore, we investigated the mechanism by which HER2 regulates cancer stem cell (CSC) activity in gastric cancer cells. <b><i>Methods:</i></b> <i>HER2</i> was transfected into MKN28 gastric cancer cells, and its role in regulating CSC activity was determined by characterizing the HER2-overexpressing cells. <b><i>Results:</i></b> The sphere formation assay revealed that the sphere sizes and frequency of sphere formation were significantly greater for the HER2-overexpressing cells than for the MKN28 control cells. The CSC markers Oct-4 and BMI1 were more highly expressed in the HER2-overexpressing cells, as were the EMT markers. This was accompanied by a significant enhancement in cellular invasion of the Matrigel and migration. The E-cadherin level was significantly downregulated, and the mesenchymal marker Snail upregulated, in the <i>HER2</i>-transfected cells. HER2 overexpression activated the well-characterized CSC-associated Wnt/β-catenin signaling pathway, as shown by the luciferase assay. After treatment of these cells with the Wnt signal inhibitor PRI-724, the BMI1 and Oct-4 levels were decreased for 24 h and Snail was also downregulated. Immunofluorescence staining revealed the significant restoration of E-cadherin levels in the <i>HER2</i>-transfected cells after PRI-724 treatment. <b><i>Conclusions:</i></b> These results established a role for HER2 in regulating gastric CSC activity, with Wnt/β-catenin signaling being mediated via a HER2-dependent pathway. In summary, HER2-overexpressing gastric cancer cells exhibited increased stemness and invasiveness and were regulated by Wnt/β-catenin signaling. HER2;Gastric cancer;Cancer stem cell;Epithelial-to-mesenchymal transition;Wnt 2019-09-24
    https://karger.figshare.com/articles/dataset/Supplementary_Material_for_HER2_Regulates_Cancer_Stem_Cell_Activities_via_the_Wnt_Signaling_Pathway_in_Gastric_Cancer_Cells/9897278
10.6084/m9.figshare.9897278.v1