The secretory proprotein convertases furin, PC5, and PC7 activate VEGF-C to induce tumorigenesis
Geraldine Siegfried, … , Nabil G. Seidah, Abdel-Majid Khatib
Geraldine Siegfried, … , Nabil G. Seidah, Abdel-Majid Khatib
Published June 1, 2003
Citation Information: J Clin Invest. 2003;111(11):1723-1732. https://doi.org/10.1172/JCI17220.
View: Text | PDF
Article Oncology Article has an altmetric score of 6

The secretory proprotein convertases furin, PC5, and PC7 activate VEGF-C to induce tumorigenesis

Abstract

The secretory factor VEGF-C has been directly implicated in various physiological processes during embryogenesis and human cancers. However, the importance of the conversion of its precursor proVEGF-C to mature VEGF-C in tumorigenesis, and vessel formation and the identity of the protease(s) that regulate these processes is/are not known. The intracellular processing of proVEGF-C that occurs within the dibasic motif HSIIRR227SL suggests the involvement of the proprotein convertases (PCs) in this process. In addition, furin and VEGF-C were found to be coordinately expressed in adult mouse tissues. Cotransfection of the furin-deficient colon carcinoma cell line LoVo with proVEGF-C and different PC members revealed that furin, PC5, and PC7 are candidate VEGF-C convertases. This finding is consistent with the in vitro digestions of an internally quenched synthetic fluorogenic peptide mimicking the cleavage site of proVEGF-C (220Q-VHSIIRR↓SLP230). The processing of proVEGF-C is blocked by the inhibitory prosegments of furin, PC5, and PACE4, as well as by furin-motif variants of α2-macroglobulin and α1-antitrypsin. Subcutaneous injection of CHO cells stably expressing VEGF-C into nude mice enhanced angiogenesis and lymphangiogenesis, but not tumor growth. In contrast, expression of proVEGF-C obtained following mutation of the cleavage site (HSIIRR227SL to HSIISS227SL) inhibits angiogenesis and lymphangiogenesis as well as tumor growth. Our findings demonstrate the processing of proVEGF-C by PCs and highlight the potential use of PC inhibitors as agents for inhibiting malignancies induced by VEGF-C.

Authors

Geraldine Siegfried, Ajoy Basak, James A. Cromlish, Suzanne Benjannet, Jadwiga Marcinkiewicz, Michel Chrétien, Nabil G. Seidah, Abdel-Majid Khatib

×

Figure 2

Options: View larger image (or click on image) Download as PowerPoint
In vitro digestions of Q-h-VEGF-C with recombinant furin, PC5, and PC7. ...
In vitro digestions of Q-h-VEGF-C with recombinant furin, PC5, and PC7. (a) RP-HPLC chromatogram of the crude digest following 4 hours of incubation at 37°C of 20 μg of QVEGF-C with furin, PC5, or PC7 in 25 mM Tris, 25 mM Mes, and 2.5 mM CaCl2, pH 7.4. The elution of the peaks was monitored on-line by UV absorbance at 214 nm as well as by fluorescence detectors (λex, 320 nm; λem, 420 nm). (b) MALDI-ToF mass spectra of the crude digests following 24 hours of incubation at 37°C of 20 μg of QVEGF-C with furin, PC5, and PC7 in 25 mM Tris, 25 mM Mes, and 2.5 mM CaCl2, pH 7.4. Note the absence of the peak at m/z 1,703 suggesting complete cleavage of QVEGF-C. The peaks at m/z 1,129 and 595 were attributed to the highly fluorescent N-terminal (NT) (Abz-Q-VHSIIRR-OH) and the nonfluorescent C-terminal (CT) [SLP(NO2)-A-CONH2] fragments, respectively. The peaks at m/z 972 and 663 are not PC-dependent since they are also present in the crude digest of QVEGF-C by wild-type medium (data not shown). NT-R, the N-terminal sequence without Arginine residue.