Dataset Information

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

ABSTRACT: 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.

SUBMITTER: Kanthou C

PROVIDER: S-EPMC4131915 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundDifferent isoforms of VEGF-A (mainly VEGF₁₂₁, VEGF₁₆₅ and VEGF189) have been shown to display particular angiogenic properties in the generation of a functional tumor vasculature. Recently, a novel class of VEGF-A isoforms, designated as VEGF(xxx)b, generated through alternative splicing, have been described. Previous studies have suggested that these isoforms may inhibit angiogenesis. In the present work we have produced recombinant VEGF₁₂₁/₁₆₅b proteins in the yeast Pichia pastoris and constructed vectors to overexpress these isoforms and assess their angiogenic potential.ResultsRecombinant VEGF₁₂₁/₁₆₅b proteins generated either in yeasts or mammalian cells activated VEGFR2 and its downstream effector ERK1/2, although to a lesser extent than VEGF₁₆₅. Furthermore, treatment of endothelial cells with VEGF₁₂₁/₁₆₅b increased cell proliferation compared to untreated cells, although such stimulation was lower than that induced by VEGF₁₆₅. Moreover, in vivo angiogenesis assays confirmed angiogenesis stimulation by VEGF₁₂₁/₁₆₅b isoforms. A549 and PC-3 cells overexpressing VEGF₁₂₁b or VEGF₁₆₅b (or carrying the PCDNA3.1 empty vector, as control) and xenotransplanted into nude mice showed increased tumor volume and angiogenesis compared to controls. To assess whether the VEGF(xxx)b isoforms are differentially expressed in tumors compared to healthy tissues, immunohistochemical analysis was conducted on a breast cancer tissue microarray. A significant increase (p < 0.05) in both VEGF(xxx)b and total VEGF-A protein expression in infiltrating ductal carcinomas compared to normal breasts was observed. A positive significant correlation (r = 0.404, p = 0.033) between VEGF(xxx)b and total VEGF-A was found.ConclusionsOur results demonstrate that VEGF₁₂₁/₁₆₅b are not anti-angiogenic, but weakly angiogenic isoforms of VEGF-A. In addition, VEGF(xxx)b isoforms are up-regulated in breast cancer in comparison with non malignant breast tissues. These results are to be taken into account when considering a possible use of VEGF₁₂₁/₁₆₅b-based therapies in patients.

Project description:Mesenchymal stem cells (MSCs) affect diverse aspects of tumor progression, such as angiogenesis, tumor growth and metastasis. Bone marrow MSCs (BM?MSCs) are fibroblast?like cells with multipotent differentiation ability, that localize to areas of tissue damage, including wounds and solid tumors. The tumor suppressor gene, p53, is functionally involved in cell cycle control, apoptosis and genomic stability, and is mutated and inactivated in most human cancers. The present study aimed to investigate the role of p53 in the biology of BM?MSCs. In the present study, p53 wild?type (p53+/+), knockdown (p53+/?) and knockout (p53?/?) mouse BM?MSCs (mBM?MSCs) were observed to be similar in appearance and in the expression of cell surface biomarkers, but expressed differential p53 protein levels. The p53+/? and p53?/? mBM?MSCs demonstrated an increased proliferation rate compared with mBM?MSCs derived from p53+/+ mice. mBM?MSCs from all three groups, representing distinct p53 statuses, were unable to form tumors over a 3?month period in vivo. The adipogenic and osteogenic differentiation of mBM?MSCs was increased in the absence of p53. The colony formation and migratory abilities of p53+/? and p53?/? mBM?MSCs were markedly enhanced, and the expression levels of stem cell?associated proteins were significantly increased compared with p53+/+. The expression levels of microRNA (miR)?3152 and miR?337 were significantly increased in p53+/? and p53?/? mBM?MSCs, whereas the expression levels of miR?221, miR?155, miR?1288 and miR?4669 were significantly decreased. The expression levels of tumor necrosis factor?? and interferon???inducible protein?10 were significantly upregulated in the supernatant of p53+/? and p53?/? mBM?MSCs. Ubiquitin protein ligase E3 component n?recognin 2, RING?finger protein 31 and matrix metalloproteinase 19 were highly expressed in p53+/? and p53?/? mBM?MSCs. The results of the present study indicated that p53 may serve an important role in the biology of mBM?MSCs, and may provide novel insights into the role of cells with different p53 statuses in cancer progression.

Dataset Information

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

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets