Search results for "Neovascularization"
showing 10 items of 351 documents
Osteosarcoma cell-derived exosomes affect tumor microenvironment by specific packaging of microRNAs
2018
Abstract Bone microenvironment provides growth and survival signals essential for osteosarcoma (OS) initiation and progression. OS cells regulate communications inside tumor microenvironment through different ways and, among all, tumor-derived exosomes support cancer progression and metastasis. To define the contribution of OS-derived exosomes inside the microenvironment, we investigated the effects induced in bone remodeling mechanism and tumor angiogenesis. We demonstrated that exosomes promoted osteoclasts differentiation and bone resorption activity. Furthermore, exosomes potentiated tube formation of endothelial cells and increased angiogenic markers expression. We therefore investigat…
Antitumor effect of B16 melanoma cells genetically modified with the angiogenesis inhibitor rnasin.
2001
The growth of new blood vessels is an essential condition for the development of tumors with a diameter greater than 1-2 mm and also for their metastatic dissemination. RNasin, the placental ribonuclease inhibitor, is known to have antiangiogenic activity through the inhibition of angiogenin and basic fibroblast growth factor. Nevertheless, the administration of the recombinant form of a protein poses several limitations; as a result, we have studied the antitumor effect of RNasin in a murine gene therapy model. RNasin cDNA was subcloned into the pcDNA3 expression vector, and the resulting recombinant plasmid was used to transfect the B16 murine melanoma cell line. An RNasin inverted constr…
Angiogenesis in neuroblastoma: relationship to survival and other prognostic factors in a cohort of neuroblastoma patients.
2000
PURPOSE: To study angiogenesis in neuroblastoma, using morphometric and computerized image analysis, and correlate the results with survival and other prognostic factors. PATIENTS AND METHODS: Sixty-nine patients from the Spanish Cooperative Study for Neuroblastoma were studied. Tumoral angiogenesis was studied using an avidin-biotin immunoperoxidase technique with an anti-CD34 antibody. Vascular parameters (VPs) were analyzed by a computerized system. Statistical analysis was also performed. RESULTS: Sixty-six samples had adequate tumoral tissue, and their tumoral vessels were counted. Endothelial cells were more prominent in pure neuroblastomas than in maturing and more mature tumors. VP…
Adnectin CT-322 inhibits tumor growth and affects microvascular architecture and function in Colo205 tumor xenografts
2010
Antiangiogenesis has become a promising pillar in modern cancer therapy. This study investigates the antiangiogenic effects of the PEGylated Adnectin™, CT-322, in a murine Colo-205 xenograft tumor model. CT-322 specifically binds to and blocks vascular endothelial growth factor receptor (VEGFR-2). Adnectins are a novel class of targeted biologics engineered from the 10th domain of human fibronectin. CT-322 treated tumors exhibited a significant reduction in tumor growth of 69%, a 2.8 times lower tumor surface area and fewer necrotic areas. Control tumors showed a 2.36-fold higher microvessel density (MVD) and a 2.42 times higher vessel volume in corrosion casts. The vascular architecture in…
PDGFRβ and FGFR2 mediate endothelial cell differentiation capability of triple negative breast carcinoma cells
2014
Triple negative breast cancer (TNBC) is a very aggressive subgroup of breast carcinoma, still lacking specific markers for an effective targeted therapy and with a poorer prognosis compared to other breast cancer subtypes. In this study we investigated the possibility that TNBC cells contribute to the establishment of tumor vascular network by the process known as vasculogenic mimicry, through endothelial cell differentiation. Vascular-like functional properties of breast cancer cell lines were investigated in vitro by tube formation assay and in vivo by confocal microscopy, immunofluorescence or immunohistochemistry on frozen tumor sections. TNBCs express endothelial markers and acquire th…
Vascularity, perfusion rate and local tissue oxygenation of tumors derived from ras-transformed fibroblasts.
2007
Tumors derived from ras-transformed rat fibroblasts were investigated in order to gain insight into possible interrelationships between oncogenic transformations and therapeutically relevant parameters of the metabolic micromilieu of solid tumors in vivo. Tumors grew in nude mice after injection of in vitro-passaged cells. Growth rates, early stages of angiogenesis, perfusion and tissue oxygenation were assessed. Compared with the parental cell line, both ras transformants grew very rapidly and exhibited an early onset of angiogenesis. Perfusion rates of one ras-transformed tumor line were similar to those of the parental tumors whereas reduced flow values were detected in tumors of the oth…
Identification and validation of novel ERBB2 (HER2, NEU) targets including genes involved in angiogenesis.
2005
V-erb-b2 erythroblastic leukemia viral oncogene homolog 2 (ERBB2; synonyms HER2, NEU) encodes a transmembrane glycoprotein with tyrosine kinase-specific activity that acts as a major switch in different signal-transduction processes. ERBB2 amplification and overexpression have been found in a number of human cancers, including breast, ovary and kidney carcinoma. Our aim was to detect ERBB2-regulated target genes that contribute to its tumorigenic effect on a genomewide scale. The differential gene expression profile of ERBB2-transfected and wild-type mouse fibroblasts was monitored employing DNA microarrays. Regulated expression of selected genes was verified by RT-PCR and validated by West…
Tumor and its microenvironment: a synergistic interplay.
2013
The mutual and interdependent interaction between tumor and its microenvironment is a crucial topic in cancer research. Recently, it was reported that targeting stromal events could improve efficacies of current therapeutics and prevent metastatic spreading. Tumor microenvironment is a "complex network" of different cell types, soluble factors, signaling molecules and extracellular matrix components, which orchestrate the fate of tumor progression. As by definition, cancer stem cells (CSCs) are proposed to be the unique cell type able to maintain tumor mass and survive outside the primary tumor at metastatic sites. Being exposed to environmental stressors, including reactive oxygen species …
Tumor-intrinsic and -extrinsic roles of c-Kit: mast cells as the primary off-target of tyrosine kinase inhibitors.
2011
c-Kit tyrosine kinase receptor and its ligand stem cell factor have multiple functions during development, whereas in adulthood they are mostly needed for stem cell (SC) maintenance and mast cell (MC) biology. c-Kit plays an essential tumor-cell-intrinsic role in many types of cancer, either providing the tumorigenic force when aberrantly activated or conferring stem-like features characterizing the most aggressive variants. A tumor-cell-extrinsic role occurs through c-Kit-dependent accessory cells (such as MCs) that infiltrate tumors and deeply influence their progression. c-Kit-targeted therapy with tyrosine kinase inhibitors (TKIs) may ideally work against both tumor and stromal cells. H…
Induction of apoptosis and inhibition of cell growth in human hepatocellular carcinoma cells by COX-2 inhibitors
2005
The aim of the present study was to examine the effects of nonselective (indomethacin) and selective cyclooxygenase-2 (COX-2) inhibitors (NS-398, nimesulide, and CAY10404) on cell growth, cell cycle distribution, and apoptosis in three human hepatocellular carcinoma cell lines (HepG2, HuH-6, and HA22T/VGH) with different characteristics of differentiation and biological behavior. The four COX inhibitors showed a dose-dependent growth-inhibitory effect in all the cell lines. No substantial arrests in the progression of the cells through the cell cycle were observed after treatment of HuH-6 or HA22T/VGH for 48 h with the various inhibitors. On the other hand, there were significant increases …