Effect of MUC1/β-catenin interaction on the tumorigenic capacity of pancreatic CD133+cells.
Despite the fact that the biological function of cluster of differentiation (CD)133 remains unclear, this glycoprotein is currently used in the identification and isolation of tumor-initiating cells from certain malignant tumors, including pancreatic cancer. In the present study, the involvement of mucin 1 (MUC1) in the signaling pathways of a highly tumorigenic CD133+ cellular subpopulation sorted from the pancreatic cancer cell line HPAF-II was evaluated. The expression of MUC1-cytoplasmic domain (MUC1-CD) and oncogenic signaling transducers (epidermal growth factor receptor, protein kinase C delta, glycogen synthase kinase 3 beta and growth factor receptor-bound protein 2), as well as the association between MUC1 and β-catenin, were characterized in HPAF-II CD133+ and CD133low cell subpopulations and in tumor xenografts generated from these cells. Compared with HPAF CD133lowcells, HPAF-II CD133+ cancer cells exhibited increased tumorigenic potential in immunocompromised mice, which was associated with overexpression of MUC1 and with the accordingly altered expression profile of MUC1-associated signaling partners. Additionally, MUC1-CD/β-catenin interactions were increased both in the HPAF-II CD133+ cell subpopulation and derived tumor xenografts compared with HPAF CD133lowcells. These results suggest that, in comparison with HPAF CD133lowcells, CD133+ cells exhibit higher expression of MUC1, which contributes to their tumorigenic phenotype through increased interaction between MUC1-CD and β-catenin, which in turn modulates oncogenic signaling cascades.
Institute of Research and Innovation in Health, University of Porto, Porto 4200-135, Portugal; Institute of Molecular Pathology and Immunology of the University of Porto, Porto 4200-135, Portugal.
Andreia Mota
AM
Sousa
Institute of Research and Innovation in Health, University of Porto, Porto 4200-135, Portugal.
Margarida
M
Rei
Institute of Research and Innovation in Health, University of Porto, Porto 4200-135, Portugal.
Rita
R
Freitas
Institute of Research and Innovation in Health, University of Porto, Porto 4200-135, Portugal; Institute of Molecular Pathology and Immunology of the University of Porto, Porto 4200-135, Portugal; Faculty of Medicine of the University of Porto, Porto 4200-319, Portugal.
Sara
S
Ricardo
Eppley Institute for Research in Cancer and Allied Disease, University of Nebraska Medical Center, Omaha, NE 68198-5950, USA.
Thomas
T
Caffrey
Institute of Research and Innovation in Health, University of Porto, Porto 4200-135, Portugal; Institute of Molecular Pathology and Immunology of the University of Porto, Porto 4200-135, Portugal; Faculty of Medicine of the University of Porto, Porto 4200-319, Portugal.
Leonor
L
David
Institute of Research and Innovation in Health, University of Porto, Porto 4200-135, Portugal; Institute of Molecular Pathology and Immunology of the University of Porto, Porto 4200-135, Portugal; Faculty of Medicine of the University of Porto, Porto 4200-319, Portugal; Faculty of Sciences of the University of Porto, Porto 4169-007, Portugal.
Raquel
R
Almeida
Eppley Institute for Research in Cancer and Allied Disease, University of Nebraska Medical Center, Omaha, NE 68198-5950, USA.
Michael Anthony
MA
Hollingsworth
Institute of Research and Innovation in Health, University of Porto, Porto 4200-135, Portugal; Institute of Molecular Pathology and Immunology of the University of Porto, Porto 4200-135, Portugal; Faculty of Medicine of the University of Porto, Porto 4200-319, Portugal.
Filipe
F
Santos-Silva
MUC1; cancer stem cells; cell signaling; pancreatic cancer