Journal: Oncotarget

Article Title: Fendiline inhibits proliferation and invasion of pancreatic cancer cells by interfering with ADAM10 activation and β-catenin signaling.

doi: 10.18632/oncotarget.5933

Figure Lengend Snippet: Figure 8: PDAC tumor tissue array show enhanced expression of ADAM10: A.-C. Tumor tissue array containing normal, islet cell tumor and Grade I, II and III PDAC tissue samples were immunostained using an ADAM10 antibody A. and intensity of the stained sections were measured by Dr. Coppola, Senior Pathologist at Moffitt Cancer Center. The stain was semiquantitatively scored based on the intensity of the stain as negative (0), weak (1), moderate (2) and strong (3). In all cases at least 34% of the tumor was positive, which is shown in B. The bargraph in C. shows that ADAM10 levels are increased in tumor tissues, with Grade 1 tumors showing a significant increase. D.-J. Expression of vimentin, c-Myc and ADAM10 are significantly increased in PDAC: PDAC tissue samples and samples from normal pancreas were analyzed by western blot using vimentin (D. and H.), c-Myc (E. and I.) and ADAM10 (F. and J.) antibodies and blots were reprobed with GAPDH antibody for normalization of proteins. K. Graph plotted using the data derived from TCGA portal show that PDAC human samples show increased alterations, especially amplification and/or mutation, in ADAM10, β-catenin (CTNNB1), cyclin D1 (CCND1), CD44, Myc (MYC) and vimentin (VIM). L. Proposed signaling mechanisms by which calcium dysregulation enhances ADAM10-mediated tumor progression: Based on our data with fendiline we hypothesize that calcium influx induces ADAM10 activation, leading to enhanced cadherin cleavage, release of β-catenin, its nuclear translocation and activation of TCF/LEF containing promoters. This enhances expression of genes associated with proliferation, epithelial mesenchymal transition and metastasis of cancers such as c-Myc, cyclin D1 and CD44. Additionally, β-catenin/TCF signaling has been shown to enhance ADAM10 expression thereby playing a feed-forward role in ADAM10-mediated downstream signaling and promotion of oncogenic cycle. In addition to this indirect activation of β-catenin-TCF signaling, ADAM10-mediated cleavage of substrates such as cadherins and CD44 allow detachment of cell-cell and cell-substratum adhesions, migration and invasion of cancer cells. Our data indicate that inhibitors of calcium channels prevent ADAM10- dependent signaling and expression of c-Myc, cyclin D1 and CD44, by stabilizing cadherin-catenin interaction at the cell membrane, enhancing adherens junction formation, subsequently reducing p-catenin-TCF/LEF signaling and target gene expression.

Article Snippet: Immunohistochemical analysis of human PDAC tissue tumor microarray The PDAC tissue array was purchased from amsbio (Cambridge, MA).

Techniques: Expressing, Staining, Western Blot, Derivative Assay, Amplification, Mutagenesis, Activation Assay, Translocation Assay, Migration, Membrane, Targeted Gene Expression