Search results for " Pathologic"
showing 10 items of 285 documents
Angiogenesis-related prognosis in patients with oral squamous cell carcinoma-role of the VEGF +936 C/T polymorphism.
2014
BACKGROUND: The aim of the study was the immunohistological assessment of VEGF-single nucleotide polymorphism (SNP)-related angiogenic activity in oral squamous cell carcinoma (OSCC) in correlation with prognosis. METHODS: Fifty OSCC samples were immunostained with CD31-antibodies. Mean microvessel density (MVD) and staining intensity were determined and associated with clinicopathological/prognostic features as well as with the VEGF +936C/T SNP. RESULTS: A significant higher MVD could be seen for T3 and T4 compared with T1 and T2, N > 0 vs. N0 as well as G3–G4 vs. G1–G2 OSCCs (all: P < 0.05). A higher MVD was also associated with increased and earlier rates of local relapses, more metastas…
Endothelial VEGFR-3 expression in colorectal carcinomas is associated with hematogenous metastasis
2009
Vascular endothelial growth factor receptor 3 (VEGFR-3) is a major inducer of lymphangiogenic signalling and seems to be involved also in angiogenesis. Since both processes are closely linked with tumor metastasis this study investigated the expression of VEGFR-3 in tumor-associated vessels in colorectal carcinomas and evaluated its relevance for lymphogenous and hematogenous metastasis. In a comparative study between microvascular endothelial cells isolated from the tumor (HCTEC) and the corresponding non-neoplastic tissue (HCMEC) from five patients with colorectal cancer VEGFR-3 expression was measured using a specific ELISA. The expression pattern was individually different, with cases s…
Implanted neonatal human dermal fibroblasts influence the recruitment of endothelial cells in mice
2012
The vascularization of new tissue within a reasonable time is a crucial prerequisite for the success of different cell- and material-based strategies. Considering that angiogenesis is a multi-step process involving humoral and cellular regulatory components, only in vivo assays provide the adequate information about vessel formation and the recruitment of endothelial cells. The present study aimed to investigate if neonatal human dermal fibroblasts could influence in vivo neovascularization. Results obtained showed that fibroblasts were able to recruit endothelial cells to vascularize the implanted matrix, which was further colonized by murine functional blood vessels after one week. The ve…
Role of exosomes released by chronic myelogenous leukemia cells in angiogenesis
2012
The present study is designed to assess if exosomes released from Chronic Myelogenous Leukemia (CML) cells may modulate angiogenesis. We have isolated and characterized the exosomes generated from LAMA84 CML cells and demonstrated that addition of exosomes to human vascular endothelial cells (HUVEC) induces an increase of both ICAM-1 and VCAM-1 cell adhesion molecules and interleukin-8 expression. The stimulation of cell-cell adhesion molecules was paralleled by a dose-dependent increase of adhesion of CML cells to a HUVEC monolayer. We further showed that the treatment with exosomes from CML cells caused an increase in endothelial cell motility accompanied by a loss of VE-cadherin and β-ca…
Tumor Hypoxia: Causative Factors, Compensatory Mechanisms, and Cellular Response
2004
Abstract Learning Objectives After completing this course, the reader will be able to: Explain the effect of hypoxia on resistance to treatment. Describe the causes of tumor hypoxia. Characterize cellular response to hypoxia. Access and take the CME test online and receive 1 hour of AMA PRA category 1 credit at CME.TheOncologist.com Hypoxia is a characteristic feature of locally advanced solid tumors resulting from an imbalance between oxygen (O2) supply and consumption. Major causative factors of tumor hypoxia are abnormal structure and function of the microvessels supplying the tumor, increased diffusion distances between the nutritive blood vessels and the tumor cells, and reduced O2 tra…
Bortezomib: a new pro-apoptotic agent in cancer treatment.
2010
Bortezomib is a proteasome inhibitor. It targets the ubiquitin-proteasome pathway with subsequent inhibition of the degradation of proteins involved in cell cycle regulation and cancer cell survival. The best known molecular mechanism concerns the inhibition of IkappaB breakdown and the related stabilization of NFkappaB, thus preventing its translocation to the nucleus for the activation of downstream pathways. Bortezomib is the only drug in this class which has been approved for clinical use. It has shown an efficient antitumor effect in a phase III clinical trial (APEX) involving relapsed multiple myeloma patients. Response rate, time to progression and overall survival have been improved…
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…
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…