Characterisation of the interaction of heterodimeric αvβ6 integrin with urokinase plasminogen activator receptor (uPAR) — ASN Events
  1. Schedule
  2. Lunch & Poster Session One
  3. Characterisation of the interaction of heterodimeric αvβ6 integrin with urokinase plasminogen activator receptor (uPAR)

Characterisation of the interaction of heterodimeric αvβ6 integrin with urokinase plasminogen activator receptor (uPAR) (#118)

Seong B Ahn 1 , Samyuktha Anand 2 , Abidali Mohamedali 2 , Harish Cheruku 1 , Debra Birch 2 , Gopichandran Sowmya 2 , David I Cantor 1 , Shoba Ranganathan 2 , David W Inglis 3 , Ronald Frank 4 , Miachael Agrez 5 , Edouard C Nice 6 , Mark S Baker 1
  1. Australian School of Advanced Medicine, Macquarie University, North Ryde, NSW, Australia
  2. Chemistry and Biomolecular Sciences, Macquarie University, North Ryde, NSW, Australia
  3. Department of Engineering, Macquarie University, North Ryde, NSW, Australia
  4. Department of Chemical Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
  5. Division of Surgery, John Hunter Hospital, Newcastle, NSW , Australia
  6. Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia

Urokinase plasminogen activator receptor (uPAR) and the epithelial integrin αvβ6 play critical roles in cancer metastasis. Importantly, both these interacting molecules have been implicated in epithelial-mesenchymal transition (EMT) changes that facilitate escape of metastatic cells from tissue barriers. This study aims to characterise the uPAR•αvβ6 in ovarian and colon cancer cells.

The study uses orthogonal in cellulo and in vitro approaches to characterise the uPAR•αvβ6 interaction on OVCA429 (ovarian cancer cell line) and four different colon cancer cell lines with modified β6 subunit expression (SW480Mock, SW480β6OE, HT29Mock and HT29β6AS). Proximity ligation assays (PLA) was used to confirm the previously identified uPAR•αvβ6 interaction site. Peptide arrays were used to identify the specific sites of interaction which also validates our PLA studies. In silico structural analysis was then used to identify the most likely uPAR•αvβ6 interaction sites based on the peptide array data.

PLA study confirmed the uPAR•αvβ6 interaction in our cell lines. PLA studies were further validated using peptide arrays to identify potential physical sites of uPAR•αvβ6 interaction and as well as interactions with other known uPAR partners (e.g., uPA and vitronectin) and individual integrin subunits (i.e., αv, β1, β3 and β6). Our data suggests that interaction with uPAR requires expression of the complete αβ heterodimer rather than either individual subunits (i.e., αv, β1, β3 or β6). Finally, from the in silico structural analysis, it appears the most likely unique site/s of interaction of αvβ6 with uPAR are located in uPAR domain II and domain III. Functional consequences of disrupting uPAR•αvβ6 as a novel therapeutic target to ablate metastasis are explored. (Pubmed ID: 25318615)