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Query: UMLS:C1519670 (tumor angiogenesis)
6,052 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human prostatic cancer cells have a remarkably low rate of proliferation even when they have metastasized to the bone and have become androgen independent (Berges et al., Clin. Cancer Res., 1:473-480, 1995). Due to this low proliferation, patients with such androgen-independent metastatic prostatic cancer cells are rarely treated successfully with the presently available chemotherapeutic agents. Therefore, new approaches are urgently needed which are not dependent on the rate of cancer cell proliferation for their effectiveness. One such approach is to inhibit the angiogenic response within localized and metastatic cancer deposits, since the resultant hypoxia-induced tumor cell death does not require cell proliferation. We have previously demonstrated that the quinoline-3-carboxamide, linomide, is an p.o. active agent which inhibits tumor angiogenesis and thus blood flow in a variety of rat prostatic cancers independent of their growth rate, androgen sensitivity, or metastatic ability. Because of its antiangiogenic effects, linomide treatment induces the hypoxic death of rat prostatic cancer cells, thus inhibiting their net growth and metastases. To determine whether human prostatic cancer cells are similarly sensitive to hypoxia-induced death caused by linomide inhibition of tumor angiogenesis, androgen-independent TSU and PC-3 human prostatic cancer cells were xenotransplanted into SCID mice that were either untreated or treated p.o. with linomide. These studies demonstrated that linomide treatment decreases microvessel density in both androgen-independent human prostatic cancers. Microvessel density was decreased from 1.8 +/- 0.4% of the total area in control tumors to 1.0 +/- 0.2% in linomide-treated TSU tumors [i.e., a 44% decrease in microvessel density (P < 0.05)]. Similarly, a 56% decrease (P < 0.05) was observed in the microvessel density of PC-3 tumors (i.e., 2.7 +/- 0.8% of the area in control tumor versus 1.2 +/- 0.2% in the linomide-treated tumors). This inhibition of angiogenesis increased cell death in both TSU and PC-3 cancer cells. This is reflected in both an increase in the area of necrosis and an increase in the apoptotic index in non-necrotic areas. In untreated TSU tumors, 40 +/- 2% of tumor volume was necrotic. Linomide treatment increased this necrotic percentage to 59 +/- 2% [i.e., 48% increase (P < 0.05)]. Linomide therapy also increased apoptotic cell death in non-necrotic tumor areas. In the untreated TSU tumors, 2.9 +/- 0.6% of tumor cells were apoptotic in the non-necrotic areas, and in the linomide-treated TSU tumors this percentage increased to 3.6 +/- 0.4% [i.e., 24% increase (P < 0.05)].(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Human prostatic cancer cells are sensitive to programmed (apoptotic) death induced by the antiangiogenic agent linomide. 754 15

The regulation of tumor growth by cytokine-induced alterations in host effector cell recruitment and activation is intimately associated with leukocyte adhesion and angiogenic modulation. In the present study, we have developed a novel tumor model to investigate this complex series of events in response to cytokine administration. Gelatin sponges containing recombinant human basic fibroblast growth factor (rhFGFb) and B16F10 melanoma cells were implanted onto the serosal surface of the left lateral hepatic lobe in syngeneic C57BL/6 mice. The tumor model was characterized by progressive tumor growth initially localized within the sponge and the subsequent development of peritoneal carcinomatosis. Microscopic examination of the sponge matrix revealed well developed tumor-associated vascular structures and areas of endothelial cell activation as evidenced by leukocyte margination. Treatment of mice 3 days after sponge implantation with a therapeutic regimen consisting of pulse recombinant human interleukin-2 (rhIL-2) combined with recombinant murine interleukin-12 (rmIL-12) resulted in a marked hepatic mononuclear infiltrate and inhibition of tumor growth. In contrast to the control group, sponges from mice treated with rhIL-2/rmIL-12 demonstrated an overall lack of cellularity and vascular structure. The regimen of rhIL-2 in combination with rmIL-12 was equally effective against gelatin sponge implants of rhFGFb/B16F10 melanoma in SCID mice treated with anti-asialo-GM1 in the absence of a mononuclear infiltration, suggesting that T, B, and/or NK cells were not the principal mediators of the anti-tumor response in this tumor model. The absence of vascularity within the sponge after treatment suggests that a potential mechanism of rhIL-2/rmIL-12 anti-tumor activity is the inhibition of neovascular growth associated with the establishment of tumor lesions. This potential mechanism could be dissociated from the known activities of these two cytokines to induce the recruitment and activation of host effector cells. Moreover, this model provides a unique opportunity to study the cellular and molecular mechanism(s) underlying both tumor angiogenesis and leukocyte recruitment to metastatic lesions.
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PMID:Regulation of local host-mediated anti-tumor mechanisms by cytokines: direct and indirect effects on leukocyte recruitment and angiogenesis. 913 9

In this study, we investigated the effects of human type I consensus interferon (IFN-con1) (Amgen) gene transfer into body cavity-based lymphomas (BCBL)-1 cells, which are latently infected with Kaposi's sarcoma-associated herpesvirus (KSHV) human herpesvirus-8 (HHV-8). Both the basal and 12-O-tetradecanoyl phorbol-13-acetate (TPA)-stimulated production of KSHV/HHV-8 mature virions was strongly inhibited in genetically modified IFN-producing BCBL-1 cells as compared with parental or control transduced counterparts. A similar inhibition was obtained on treatment of parental BCBL-1 cells with exogenous IFN-con1. The reduction in KSHV/HHV-8 production was associated with a decrease in the basal and TPA-stimulated intracellular amount of the linear form of the viral genome. Interestingly, 25%40% of the IFN-producing BCBL-1 cell population underwent spontaneous apoptosis in vitro. TPA treatment, which did not significantly affect the viability of the parental and control BCBL-1 cells, resulted in the apoptotic death of up to 70% of the IFN-producing cell population. Addition of exogenous IFN-con1 to parental BCBL-1 cells produced similar effects, although less intense. Injection of either parental or control-transduced BCBL-1 cells into SCID mice resulted in progressively growing tumors characterized by an unusually high level of tumor angiogenesis. In contrast, complete tumor regression was observed in all the mice injected either subcutaneously (s.c.) or intraperitoneally (i.p.) with the IFN-producing BCBL-1 cells. These results represent the first evidence that type I IFN can counteract the activation of a productive herpesvirus infection in latently infected tumor cells by the induction of apoptosis, providing an interesting link between the antiviral and antitumor activities of this cytokine. These data suggest the possible advantages of strategies of type I IFN gene transfer (with respect to the use of the exogenous cytokine) for the treatment of patients with some HHV-8-induced malignancies.
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PMID:Type I consensus IFN (IFN-con1) gene transfer into KSHV/HHV-8-infected BCBL-1 cells causes inhibition of viral lytic cycle activation via induction of apoptosis and abrogates tumorigenicity in sCID mice. 1057 24

Interleukin-18 (IL-18), also called interferon-gamma (IFN-gamma)-inducing factor, has recently been characterized as a potent IFN-gamma-inducing cytokine. We now report that IL-18 is a novel antiangiogenic and antitumor cytokine. In vitro, IL-18 specifically inhibits fibroblast growth factor-2-stimulated proliferation of capillary endothelial cells. In vivo, IL-18 is sufficiently potent to suppress the fibroblast growth factor-induced corneal neovascularization by systemic administration in mice. This cytokine also inhibits embryonic angiogenesis in the chick chorioallantoic membrane assay. Systemic and intralesional administrations of IL-18 produce a significant suppression of the growth of murine T241 fibrosarcoma in syngeneic C57Bl6/J and immunodeficient SCID mice. The antitumor effect appears to be potent because an average of >75% inhibition of primary tumor growth was observed at a dose of 50 microg/kg/day. In cell culture, murine T241 fibrosarcoma cells are insensitive to recombinant IL-18 at concentrations that significantly inhibit endothelial cell proliferation. Immunohistochemical studies of tumor tissues reveal hypovascularization of the IL-18-treated tumors. These results suggest that IL-18 may participate in the regulation of a switch of tumor angiogenesis.-Cao, R., Farnebo, J., Kurimoto, M., Cao, Y. Interleukin-18 acts as an angiogenesis and tumor suppressor.
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PMID:Interleukin-18 acts as an angiogenesis and tumor suppressor. 1059 67

Interleukin 12 (IL-12) is a heterodimeric cytokine that exerts a potent antitumor effect through its pleiotropic actions. It was recently reported that IL-12 has also a potent antiangiogenic effect through the induction of IFN-gamma, which triggers the production of chemokines such as IP-10 that has been shown to have antiangiogenesis properties. In this study we transfected the IL-12 gene into a human pancreatic adenocarcinoma cell line (PK-1). PK-1 cells transfected with the green fluorescence protein (gfp) gene were used as positive controls. The in vitro growth curve and in vivo tumor growth of transfectants (IL-12/PK-1 and gfp/PK-1) were compared with those of parental cells. The SCID mice used in this study were administered antiasialo GM-1 Ab (100 microg, i.p., twice weekly) to deplete the remaining immunoeffector cells, NK cells. Using a skinfold chamber model, we observed and recorded tumor angiogenesis by intravital microscopy. In vitro growth of IL-12/PK-1 and gfp/PK-1 cells was not different from that of wild-type PK-1 cells (wt/PK-1). However, IL-12 transfected PK-1 cells did not develop into tumors as did the wt/PK-1 cells after subcutaneous inoculation in antiasialo GM-1 Ab administered SCID mice. The growth of IL-12/PK-1 tumors was restored in mice treated with anti-IL-12 antibody. We found that IL-12/PK-1, in contrast to gfp/PK-1 and wt/PK-1, failed to initiate an angiogenic response, as observed in the skinfold chamber model. These results indicate that the antiangiogenesis effect of IL-12 alone, without immune system involvement, is sufficient to block the growth of human pancreatic cancer.
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PMID:The antiangiogenesis effect of interleukin 12 during early growth of human pancreatic cancer in SCID mice. 1076 47

Progressive growth and metastasis of solid tumors require angiogenesis, or the formation of new blood vessels. Endostatin is a 20-kDa carboxy-terminal fragment of collagen XVIII that has been shown to inhibit endothelial cell proliferation and tumor angiogenesis. Replication-deficient recombinant adenovirus (rAd) vectors were constructed, which encoded secreted forms of human and mouse endostatin (HECB and MECB, respectively), and, as a control, human alkaline phosphatase (APCB). Accumulation of endostatin was demonstrated in supernatants of cultured cells infected with the endostatin rAds. These supernatants disrupted tubule formation, inhibited migration and proliferation, and induced apoptosis in human dermal vascular endothelial cells or human vascular endothelial cells. Endostatin-containing supernatants had no effect on the proliferation of MidT2-1 mouse mammary tumor cells in vitro. A pharmacokinetic study of MECB in immunocompetent FVB mice demonstrated a 10-fold increase of serum endostatin concentrations 3 days after intravenous administration of 1x10(10) particles of this rAd (215-257 ng/mL compared to 12-38 ng/mL in control rAd-treated mice). Intravenous administration of MECB reduced b-FGF stimulated angiogenesis into Matrigel plugs by 38%. Intratumoral MECB inhibited growth of MidT2-1 syngeneic mammary tumors in FVB mice, but had minimal impact on the growth of MDA-MB-231 human breast tumors in SCID mice. Intravenous therapy with MECB also initially inhibited growth of MidT2-1 tumors, but this activity was subsequently blocked by induced anti-rAd antibodies. In summary, endostatin gene therapy effectively suppressed angiogenic processes in vitro and in vivo in several model systems.
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PMID:Evaluation of endostatin antiangiogenesis gene therapy in vitro and in vivo. 1178 61

Platelet endothelial cell adhesion molecule (PECAM)-1 has been implicated in angiogenesis, but a number of issues remain unsettled, including the independent involvement of human PECAM-1 (huPECAM-1) in tumor angiogenesis and the mechanisms of its participation in vessel formation. We report for tumors grown in human skin transplanted on severe combined immunodeficiency mice that antibodies against huPECAM-1 (without simultaneous treatment with anti-VE-cadherin antibody) decreased the density of human, but not murine, vessels associated with the tumors. Anti-huPECAM-1 antibody also inhibited tube formation by human umbilical vein endothelial cells (HUVEC) and the migration of HUVEC through Matrigel-coated filters or during the repair of wounded cell monolayers. The involvement of huPECAM-1 in these processes was confirmed by the finding that expression of huPECAM-1 in cellular transfectants induced tube formation and enhanced cell motility. These data provide evidence of a role for PECAM-1 in human tumor angiogenesis (independent of VE-cadherin) and suggest that during angiogenesis PECAM-1 participates in adhesive and/or signaling phenomena required for the motility of endothelial cells and/or their subsequent organization into vascular tubes.
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PMID:Involvement of human PECAM-1 in angiogenesis and in vitro endothelial cell migration. 1194 May 33

Paclitaxel is an alkaloid that inhibits endothelial cell proliferation, motility, and tube formation at nanomolar concentrations. Cationic liposome preparations have been shown to target blood vessels. We wished to explore the possibility that paclitaxel encapsulated in cationic liposomes carries paclitaxel to blood vessels and thereby provides an antiangiogenic effect. We used a humanized SCID mouse melanoma model, which allowed us to analyze tumor growth and tumor angiogenesis in an orthotopic tumor model. Here, human melanoma cells grow on human dermis and are in part nourished by human vessels. We show that paclitaxel encapsulated in liposomes prevents melanoma growth and invasiveness and improves survival of mice. Moreover, liposome-encapsulated paclitaxel reduces vessel density at the interface between the tumor and the human dermis and reduces endothelial cell mitosis to background levels. In contrast, equimolar concentrations of paclitaxel solubilized in Cremophor EL(R) had only insignificant effects on tumor growth and did not reduce the mitotic index of endothelium in vivo, although the antiproliferative effect of solubilized paclitaxel in Cremophor EL(R)in vitro was identical to that seen with liposome-coupled paclitaxel. In conclusion, we present a model of how to exploit cytotoxic effects of compounds to prevent tumor growth by using cationic liposomes for targeting an antiproliferative drug to blood vessels.
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PMID:Paclitaxel encapsulated in cationic liposomes diminishes tumor angiogenesis and melanoma growth in a "humanized" SCID mouse model. 1260 62

Platelet endothelial cell adhesion molecule (PECAM-1/CD31), a member of the immunoglobulin superfamily expressed at high levels on endothelial cells, has been recently implicated in angiogenesis. Although antagonism of PECAM-1 inhibited neovascularization in two different animal models of growth factor/chemokine-induced angiogenesis, its participation in tumor angiogenesis has not been established. We therefore investigated its involvement in models of tumor angiogenesis in mice. An antibody against murine PECAM-1 that was shown to block in vitro murine endothelial tube formation inhibited the subcutaneous growth and tumor vascularity of three tumors in mice: A549 human non-small cell lung cancer in SCID mice, B16 murine melanoma in C57BL/6 mice and AB12 murine mesothelioma in Balb/c mice. These studies suggest a possible role for PECAM-1 in the complex process of tumor angiogenesis and provide additional evidence of the importance of endothelial cell adhesion molecules to the formation of new vessels.
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PMID:Antibody against murine PECAM-1 inhibits tumor angiogenesis in mice. 1451 36

Breast cancer is significantly less prevalent among Asian women, whose diets contain high intake of soy products and tea. The objective of our present study was to identify the combined effects of dietary soy phytochemicals and tea components on breast tumor progression in a clinically relevant in vivo model of MCF-7 androgen-dependent human breast tumor in female SCID mice. MCF-7 tumor growth, tumor cell proliferation and apoptosis, microvessel density, and expressions of tumor estrogen receptors were compared in mice treated with genistin-rich soy isoflavones (GSI), soy phytochemical concentrate (SPC), black tea (BT), green tea (GT), SPC/BT combination and SPC/GT combination. GSI and SPC led to dose-dependent inhibition of MCF-7 tumor growth via inhibition of cancer cell proliferation in vivo. GT showed more potent anti-breast tumor activity than BT. GT infusion at 1.5 g tealeaf/100 mL water produced significant (p < 0.05) reductions of 56% in final tumor weight. GT plus SPC at 0.1% of the diet further reduced final tumor weight by 72% (p < 0.005). Analysis of serum and tumor biomarkers showed that the combined effects of SPC and GT inhibited tumor angiogenesis, and reduced estrogen receptor (ER)-alpha and serum levels of insulin-like growth factor (IGF)-I. Our study suggests that dietary SPC plus GT may be used as a potential effective dietary regimen for inhibiting progression of estrogen-dependent breast cancer.
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PMID:Combined inhibition of estrogen-dependent human breast carcinoma by soy and tea bioactive components in mice. 1461 9


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