Tumour cells expressing single VEGF isoforms display distinct growth, survival and migration characteristics

• Published in: PloS one Vol. 9; no. 8; p. e104015
• Main Authors: Kanthou, Chryso, Dachs, Gabi U, Lefley, Diane V, Steele, Andrew J, Coralli-Foxon, Claudia, Harris, Sheila, Greco, Olga, Dos Santos, Sofia A, Reyes-Aldasoro, Constantino C, English, William R, Tozer, Gillian M
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 13-08-2014; Public Library of Science (PLoS)
• Subjects: AKT protein; Angiogenesis; Animals; Apoptosis; Biology and life sciences; Biomarkers; Cancer; Carcinogenesis - genetics; Cell Adhesion; Cell growth; Cell Line, Tumor; Cell migration; Cell Movement - genetics; Cell Proliferation - genetics; Cell survival; Cell Survival - genetics; Collagen; Contractility; Cyclin-dependent kinase; Cyclin-dependent kinase inhibitor p27; Elongation; Enzyme inhibitors; Extracellular signal-regulated kinase; Fibroblasts; Fibrosarcoma; Fibrosarcoma - metabolism; Fibrosarcoma - pathology; Forkhead protein; Gene Expression Regulation, Neoplastic; Growth; Isoforms; Kinases; Localization; Medical prognosis; Medical research; Medicine; Medicine and Health Sciences; Mesenchyme; Metastases; Metastasis; Mice; Motility; Neoplasm Metastasis - genetics; Oncology; Overexpression; Protein Isoforms - chemistry; Protein Isoforms - metabolism; Protein-tyrosine kinase receptors; Proteins; Receptor mechanisms; Receptors; Receptors, Vascular Endothelial Growth Factor - metabolism; Rodents; Sarcoma; Signaling; Stat3 protein; Stem cells; Transgenic animals; Tumors; Tyrosine; Vascular endothelial growth factor; Vascular Endothelial Growth Factor A - chemistry; Vascular Endothelial Growth Factor A - metabolism; United Kingdom > UK
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0104015

Vascular endothelial growth factor-A (VEGF) is produced by most cancer cells as multiple isoforms, which display distinct biological activities. VEGF plays an undisputed role in tumour growth, vascularisation and metastasis; nevertheless the functions of individual isoforms in these processes remain poorly understood. We investigated the effects of three main murine isoforms (VEGF188, 164 and 120) on tumour cell behaviour, using a panel of fibrosarcoma cells we developed that express them individually under endogenous promoter control. Fibrosarcomas expressing only VEGF188 (fs188) or wild type controls (fswt) were typically mesenchymal, formed ruffles and displayed strong matrix-binding activity. VEGF164- and VEGF120-producing cells (fs164 and fs120 respectively) were less typically mesenchymal, lacked ruffles but formed abundant cell-cell contacts. On 3D collagen, fs188 cells remained mesenchymal while fs164 and fs120 cells adopted rounded/amoeboid and a mix of rounded and elongated morphologies respectively. Consistent with their mesenchymal characteristics, fs188 cells migrated significantly faster than fs164 or fs120 cells on 2D surfaces while contractility inhibitors accelerated fs164 and fs120 cell migration. VEGF164/VEGF120 expression correlated with faster proliferation rates and lower levels of spontaneous apoptosis than VEGF188 expression. Nevertheless, VEGF188 was associated with constitutively active/phosphorylated AKT, ERK1/2 and Stat3 proteins. Differences in proliferation rates and apoptosis could be explained by defective signalling downstream of pAKT to FOXO and GSK3 in fs188 and fswt cells, which also correlated with p27/p21 cyclin-dependent kinase inhibitor over-expression. All cells expressed tyrosine kinase VEGF receptors, but these were not active/activatable suggesting that inherent differences between the cell lines are governed by endogenous VEGF isoform expression through complex interactions that are independent of tyrosine kinase receptor activation. VEGF isoforms are emerging as potential biomarkers for anti-VEGF therapies. Our results reveal novel roles of individual isoforms associated with cancer growth and metastasis and highlight the importance of understanding their diverse actions.