Data on the inhibition of cell proliferation and invasion by the D2A-Ala peptide derived from the urokinase receptor.

The data presented in this article are connected to our research article entitled "D2A-Ala peptide derived from the urokinase receptor exerts anti-tumoural effects in vitro and in vivo" (Furlan et al., 2018). These data further extend our understanding of the inhibitory effects of D2A-Ala peptide. Dose-response curve using a wide range of concentrations of D2A-Ala shows that this peptide has no effects per se on proliferation of rat smooth muscle cells (RSMC). However, D2A-Ala dose-dependently inhibits epidermal growth factor (EGF)-induced RSMC proliferation. Kinetics lasting up to seven days revealed that D2A-Ala peptide completely blocked EGF-promoted RSMC proliferation. Moreover, D2A-Ala peptide inhibited invasion of HT 1080 cells towards RSMC.

D2A sequence of the urokinase receptor induces cell growth through αvß3 integrin and EGFR.

The urokinase receptor (uPAR) stimulates cell proliferation by forming a macromolecular complex with αvß3 integrin and the epidermal growth factor receptor (EGFR, ErbB1 or HER1) that we name the uPAR proliferasome. uPAR transactivates EGFR, which in turn mediates uPAR-initiated mitogenic signal to the cell. EGFR activation and EGFR-dependent cell growth are blocked in the absence of uPAR expression or when uPAR activity is inhibited by antibodies against either uPAR or EGFR. The mitogenic sequence of uPAR corresponds to the D2A motif present in domain 2. NMR analysis revealed that D2A synthetic peptide has a particular three-dimensional structure, which is atypical for short peptides. D2A peptide is as effective as EGF in promoting EGFR phosphorylation and cell proliferation that were inhibited by AG1478, a specific inhibitor of the tyrosine kinase activity of EGFR. Both D2A and EGF failed to induce proliferation of NR6-EGFR-K721A cells expressing a kinase-defective mutant of EGFR. Moreover, D2A peptide and EGF phosphorylate ERK demonstrating the involvement of the MAP kinase signalling pathway. Altogether, this study reveals the importance of sequence D2A of uPAR, and the interdependence of uPAR and EGFR.

D2A-Ala peptide derived from the urokinase receptor exerts anti-tumoural effects in vitro and in vivo.

D2A-Ala is a synthetic peptide that has been created by introducing mutations in the original D2A sequence, 130IQEGEEGRPKDDR142 of human urokinase receptor (uPAR). In vitro, D2A-Ala peptide displays strong anti-tumoural properties inhibiting EGF-induced chemotaxis, invasion and proliferation of a human fibrosarcoma cell line, HT 1080, and a human colorectal adenocarcinoma cell line, HT 29. D2A-Ala exerts its effects by preventing EGF receptor (EGFR) phosphorylation. To test D2A-Ala in vivo, this peptide was PEGylated generating polyethyleneglycol (PEG)-D2A-Ala peptide. PEGylation did not alter the inhibitory properties of D2A-Ala. Human tumour xenografts in the immunodeficient nude mice using HT 1080 and HT 29 cell lines showed that PEG-D2A-Ala significantly prevents tumour growth decreasing size, weight and density of tumours. The most efficient doses of the peptide were 5 and 10 mg/kg, thereby relevant for possible development of the peptide into a drug against cancer in particular tumours expressing EGFR.