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Biomedical subjects

I J Fidler

Publications and source records attributed to I J Fidler.

At least 37 records · Page 2Linked to original sources
PubMed2000

Induction of angiogenesis by hyperplastic colonic mucosa adjacent to colon cancer.

We determined whether hyperplastic mucosa adjacent to colon cancer contributes to neoplastic angiogenesis. Surgical specimens of human colon cancer (40 Dukes' stage B and 34 Dukes' stage C) were analyzed by immunohistochemistry for expression of proliferative and angiogenic molecules. The mucosa adjacent to Dukes' stage C tumors (but not Dukes' stage B tumors) had a higher Ki-67 labeling index and a higher expression of epidermal growth factor receptor and transforming growth factor-alpha than distant mucosa. The expression levels of vascular endothelial growth factor, basic fibroblast growth factor, interleukin-8, and the vascular density in the adjacent mucosa were similar to those in the tumor lesions and significantly higher than those in the distant mucosa. The expression of interferon-beta inversely correlated with the level of pro-angiogenic molecules and the vascular density. The injection of metastatic human colon cancer cells and murine colon cancer cells into the cecal wall of mice induced hyperplastic changes in the adjacent mucosa which expressed higher levels of epidermal growth factor receptor, basic fibroblast growth factor, and vascular endothelial growth factor, and lower levels of interferon-beta than did the control mucosa, which directly correlated with the degree of hyperplasia. These data suggest that metastatic human colon cancer cells can induce hyperplasia in the adjacent mucosa, which in turn produces angiogenic molecules that contribute to neoplastic angiogenesis.

Animals↗
PubMed2000

Production of experimental malignant pleural effusions is dependent on invasion of the pleura and expression of vascular endothelial growth factor/vascular permeability factor by human lung cancer cells.

We determined the molecular mechanisms that regulate the pathogenesis of malignant pleural effusion (PE) associated with advanced stage of human, non-small-cell lung cancer. Intravenous injection of human PC14 and PC14PE6 (adenocarcinoma) or H226 (squamous cell carcinoma) cells into nude mice yielded numerous lung lesions. PC14 and PC14PE6 lung lesions invaded the pleura and produced PE containing a high level of vascular endothelial growth factor (VEGF)-localized vascular hyperpermeability. Lung lesions produced by H226 cells were confined to the lung parenchyma with no PE. The level of expression of VEGF mRNA and protein by the cell lines directly correlated with extent of PE formation. Transfection of PC14PE6 cells with antisense VEGF165 gene did not inhibit invasion into the pleural space but reduced PE formation. H226 cells transfected with either sense VEGF 165 or sense VEGF 121 genes induced localized vascular hyperpermeability and produced PE only after direct implantation into the thoracic cavity. The production of PE was thus associated with the ability of tumor cells to invade the pleura, a property associated with expression of high levels of urokinase-type plasminogen activator and low levels of TIMP-2. Collectively, the data demonstrate that the production of malignant PE requires tumor cells to invade the pleura and express high levels of VEGF/VPF.

Adenocarcinoma↗
PubMed2000

Differential regulation of type IV collagenases and metalloelastase in murine macrophages by the synthetic bacterial lipopeptide JBT 3002.

We determined whether the expression of matrix metalloproteinases (MMP) and tissue inhibitors of MMPs (TIMP) in murine macrophages is regulated by the novel synthetic bacterial lipopeptide JBT 3002. Multilamellar liposomes (MLV) encapsulating JBT 3002 (MLV-JBT 3002) stimulated the production of 72-kDa and 92-kDa (gelatinase A and B) type IV collagenase and inhibited the production of murine metalloelastase (MME) in a dose-dependent manner in murine peritoneal macrophages. MLV-JBT 3002 also induced production of TIMP-1. MLV-JBT 3002 did not induce collagenase production in tumor cells. Priming murine macrophages with interferon-gamma (IFN-gamma) inhibited JBT 3002-stimulated production of both MMP-9 and MMP-2 and further inhibited production of MME by a mechanism involving nitric oxide (NO). This conclusion is based on data showing that IFN-gamma failed to inhibit production of MMP in the presence of L-methyl arginine or in macrophages from inducible nitric oxide synthase knockout mice. These data suggest that JBT 3002 differentially regulates the production of various MMPs and TIMP in macrophages.

Adjuvants, Immunologic↗
PubMed2000

Mekk3 is essential for early embryonic cardiovascular development.

The early development of blood vessels consists of two phases, vasculogenesis and angiogenesis, which involve distinct and also overlapping molecular regulators, but the intracellular signal transduction pathways involved in these processes have not been well defined. We disrupted Map3k3 (also known as Mekk3), which encodes Mekk3, a member of the Mekk/Ste11 family, in mice. Map3k3-/- embryos died at approximately embryonic day (E) 11, displaying disruption of blood vessel development and the structural integrity of the yolk sac. Angiogenesis was blocked at approximately E9.5 in mutant embryos. Map3k3 disruption did not alter the expression of the genes encoding Vegf-1, angiopoietin or their receptors. The development of embryonic, but not maternal, blood vessels in the placentas of Map3k3-/- embryos was impaired, revealing an intrinsic defect in Map3k3-/- endothelial cells. Moreover, Mekk3 activated myocyte-specific enhancer factor 2C (Mef2c), a transcription factor crucial for early embryonic cardiovascular development through the p38 mitogen-activated protein kinase (Mapk) cascade. We conclude that Mekk3 is necessary for blood vessel development and may be a possible target for drugs that control angiogenesis.

Animals↗
PubMed2000

Level of interleukin-8 expression by metastatic human melanoma cells directly correlates with constitutive NF-kappaB activity.

The purpose of this study was to determine whether constitutive NF-kappaB activity regulates the expression level of interleukin-8 (IL-8) in metastatic human melanoma cells. Cultures of metastatic human A375 melanoma cells expressed higher levels of IL-8 mRNA and protein than nonmetastatic A375 human melanoma cells. No discernible differences in IL-8 half-life were found between metastatic and nonmetastatic cells, but cells that overexpressed IL-8 had a higher transcription rate and increased IL-8 promoter activity. Analysis of the IL-8 promoter using deletion mutants revealed that the region within -133 was essential for constitutive IL-8 promoter activity and that mutation of NF-kappaB binding sites eliminated the constitutive IL-8 promoter activity. The activation of constitutive IL-8 transcription directly correlated with the level of constitutive NF-kappaB activity. Transfection of melanoma cells with a dominant-negative mutant IkappaBalpha expression vector (pLXSN-IkappaBalphaM) significantly decreased the level of constitutive NF-kappaB activity and expression of IL-8, demonstrating that constitutive NF-kappaB/relA activities contribute to overexpression of IL-8 in highly metastatic human melanoma cells.

Base Sequence↗
PubMed2000

Interleukin 8: an autocrine growth factor for human ovarian cancer.

We determined whether interleukin-8 (IL-8) plays a direct role in the progressive growth of ovarian cancer cells by isolating high- and low-IL-8-producing clones from the parental Hey-A8 human ovarian cancer cell line and compared their proliferative activity and tumorigenicity in nude mice. The effect of exogenous IL-8 and mouse antihuman IL-8 neutralizing antibody on ovarian cancer cell proliferation was investigated. Finally, we studied the modulation of IL-8 production in ovarian cancer cells by sense and antisense IL-8 expression vector transfection and its effect on proliferation. The Hey-A8(H) clone was selected for its overexpression of IL-8. It has a significantly higher proliferation rate than the low-IL-8-producing clone, Hey-A8(L). Recombinant IL-8 (50 ng/ml) caused a significant increase in proliferation of Hey-A8(L) clones, and 10 microg/ml neutralizing antibody against IL-8 significantly decreased proliferative activity of both Hey-A8(H) and Hey-A8(L) clones. Enforced IL-8 expression by IL-8 expression vector transfection in Hey-A8(L) clones significantly increased tumor cell proliferation, microvessel density, and hence, tumorigenicity. We conclude that IL-8 has a direct and indirect growth-potentiating activity in human ovarian cancer cells.

Animals↗
PubMed2000

Inhibition of malignant ascites and growth of human ovarian carcinoma by oral administration of a potent inhibitor of the vascular endothelial growth factor receptor tyrosine kinases.

We determined whether inhibition of the catalytic tyrosine kinase activity of the receptors for vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) inhibits the formation of malignant ascites and the progressive growth of human ovarian carcinoma cells implanted into the peritoneal cavity of nude mice. The novel protein tyrosine inhibitor PTK 787 was evaluated in two models of human ovarian cancer: Hey-A8 cells, which express low levels of VEGF/VPF and grow as solid tumor foci on the surface of peritoneal organs, and SKOV3 i.p.1 cells, which express high levels of VEGF/VPF and grow as solid peritoneal tumors and ascites. Treatment of nude mice by daily oral administration of 50 mg/kg PTK 787 was not effective against Hey-A8 tumors. In sharp contrast, it significantly inhibited growth of SKOV3 i.p.1 cells and formation of ascites, significantly increasing survival of mice with the implants. Tumor-induced vascular hyperpermeability in the peritoneum of tumor-bearing mice was inhibited by PTK 787, which accounted for its inhibition of ascites formation. Our results suggest that blockade of the VEGF/VPF receptor may be an efficient strategy to inhibit formation of malignant ascites and growth of VEGF/VPF-dependent human ovarian carcinomas.

Administration, Oral↗
PubMed2000

Site-specific expression of transferrin receptor by human colon cancer cells directly correlates with eradication by antitransferrin recombinant immunotoxin.

We determined the efficacy of HB21(Fv)PE40, a single-chain immunotoxin made by fusing the variable regions of a monoclonal antibody directed at the human transferrin receptor (TfR) with a truncated mutant of Pseudomonas exotoxin (PE), against metastatic human colon carcinoma KM12L4 cells growing in the liver or subcutis of nude mice. Organ-specific modulation of TfR expression was examined by immunohistochemistry and flow cytometry using anti-human CD71 antibody. KM12L4 cells expressed human TfR and were lysed in vitro by HB21(Fv)PE40 but not LMB-7 (a control immunotoxin specific for a Lewis Y-related carbohydrate antigen). KM12L4 cells growing in the liver expressed higher levels of TfR than cells growing s.c. Systemic administration of HB21(Fv)PE40 eliminated KM12L4 liver metastasis, whereas administration of LMB-7 did not. Treatment of mice with HB21(Fv)PE40 only delayed the growth of s.c. tumors. KM12L4 cells recovered from liver metastases, expressed higher levels of TfR, and were more sensitive to lysis by HB21(Fv)PE40 than KM12L4 cells recovered from s.c. tumors. Indeed, collectively, the data show that the expression level of the TfR by human colon cancer cells is modulated by the organ microenvironment which can be advantageous for the use of therapeutic immunotoxins.

Animals↗
PubMed2000

Differential expression of E-cadherin and type IV collagenase genes predicts outcome in patients with stage I non-small cell lung carcinoma.

Because routine histopathological examination of primary non-small cell lung cancer does not predict disease outcome, we correlated disease outcome with the expression level of multiple genes that regulate distinct steps of the metastatic process in 60 formalin-fixed, paraffin-embedded, archival specimens of stage I lung carcinoma from patients undergoing curative surgery at the M. D. Anderson Cancer Center. The expression of E-cadherin (related to cell cohesion), type IV collagenase [matrix metalloproteinase (MMP)-2 and MMP-9, related to invasion], and three angiogenic molecules, basic fibroblast growth factor, vascular endothelial growth factor/vascular permeability factor, and interleukin 8, were examined by a colorimetric in situ mRNA hybridization technique. The expression levels of the individual genes analyzed by a Cox univariate analysis were not prognostic. In contrast, the ratio between expression of type IV collagenases (mean of the expression of MMP-2 and MMP-9) and E-cadherin, the MMP:E-cadherin ratio (measured at the periphery of each tumor), was significantly higher in patients with recurrent disease than in patients who remained disease free (P = 0.00003). Longer overall survival and reduced disease recurrence rates were significantly associated with a lower MMP:E-cadherin ratio (<2) by a Kaplan-Meier survival analysis (P = 0.0002 and P = 0.0001, respectively). Multiple covariate analyses of overall and disease-free survival also concluded that the MMP:E-cadherin ratio was a significant prognostic factor when corrected for age (P = 0.0001). Determination of this gene expression ratio in individual human lung cancers might therefore be used to direct tailored treatment for individual patients with resectable lung cancer.

Adult↗
PubMed2000

Treatment for malignant pleural effusion of human lung adenocarcinoma by inhibition of vascular endothelial growth factor receptor tyrosine kinase phosphorylation.

Malignant pleural effusion (PE) is associated with advanced human lung cancer. We found recently, using a nude mouse model, that vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) is responsible for PE induced by non-small cell human lung carcinoma cells. The purpose of this study was to determine the therapeutic potential of a VEGF/VPF receptor tyrosine kinase phosphorylation inhibitor, PTK 787, against PE formed by human lung adenocarcinoma (PC14PE6) cells. PTK 787 did not affect the in vitro proliferation of PC14PE6 cells, whereas it specifically inhibited proliferation of human dermal microvascular endothelial cells stimulated by VEGF/VPF. A specific platelet-derived growth factor receptor tyrosine kinase inhibitor, CGP57148 (used as a control because PTK 787 also inhibits platelet-derived growth factor receptor tyrosine kinases), had no effect on proliferation of PC14PE6 or human dermal microvascular endothelial cells. i.v. injection of PC14PE6 cells into nude mice produced lung lesions and a large volume of PE containing a high level of VEGF/VPF. Oral treatment with CGP57148 had no effect on PE or lung metastasis. In contrast, oral treatment with PTK 787 significantly reduced the formation of PE but not the number of lung lesions. Furthermore, treatment with PTK 787 significantly suppressed vascular hyperpermeability of PE-bearing mice but did not affect the VEGF/VPF level in PE or expression of VEGF/VPF protein and mRNA in the lung tumors of PC14PE6 cells in vivo. These findings indicate that PTK 787 reduced PE formation mainly by inhibiting vascular permeability, suggesting that this VEGF/VPF receptor tyrosine kinase inhibitor could be useful for the control of malignant PE.

Adenocarcinoma↗
PubMed2000

Angiogenesis and cancer metastasis.

The growth and spread of neoplasms depends on the establishment of an adequate blood supply, that is, angiogenesis. The onset of angiogenesis involves a change in the local equilibrium between proangiogenic and antiangiogenic regulators that are produced by tumor cells, surrounding stromal cells, and infiltrating leukocytes. In most normal tissues, factors that inhibit angiogenesis predominate, whereas in rapidly dividing tissues, the balance of angiogenic molecules favors stimulation of the process. A potent inhibitor of angiogenesis is interferon-alpha or -beta, shown to down-regulate transcription and protein production of basic fibroblast growth factor, collagenase type IV, and interleukin-8. The daily systemic administration of low (but not high) dose of interferon-alpha can produce significant inhibition of angiogenesis and, hence, regression of human tumors implanted orthotopically in nude mice. The recent elucidation of the interaction among proangiogenic molecules during physiological processes and the apparent disruption of this balance in neoplasia should allow the design of potent antiangiogenic therapies against primary cancers and metastases.

Animals↗
PubMed2000

Relative expression of type IV collagenase, E-cadherin, and vascular endothelial growth factor/vascular permeability factor in prostatectomy specimens distinguishes organ-confined from pathologically advanced prostate cancers.

The tumor grade (Gleason score) in the biopsy and pretherapy prostate-specific antigen level do not accurately predict disease outcome of individual patients' prostate cancer. We used a rapid colorimetric in situ hybridization technique to evaluate the expression level of E-cadherin (which affects cell cohesion); matrix metalloproteinases (MMPs) types 2 and 9 (which affect invasion); and vascular endothelial growth factor/vascular permeability factor (which affects angiogenesis) in archival prostatectomy specimens from 40 patients. Intratumoral heterogeneity for gene expression (edge versus center versus perineural area) was more pronounced in advanced cancers than in those that were organ confined. Regardless of Gleason score, the highest expression level for E-cadherin was found in the center or perineural area of the tumors, whereas the highest expression levels for MMP-2 and MMP-9 were associated with the invasive edge. The relationship between advancing pathological stage and expression of all four metastasis-related genes was highly significant. Decreased expression of E-cadherin and increased expression of MMP-2, MMP-9, and vascular endothelial growth factor/vascular permeability factor were associated with the Gleason score of the tumors. Irrespective of serum prostate-specific antigen level or Gleason score, the ratio between expression of MMPs and E-cadherin at the invasive edge of tumors exhibited the strongest association with nonorgan-confined prostate cancer. These data suggest that the relative expression of metastasis-related genes in radical prostatectomy specimens can distinguish between organ-confined and advanced prostate cancers and provides the rationale for a prospective study correlating gene expression in pretherapy core biopsies with outcome.

Biopsy↗
PubMed2000

Nuclear factor-kappaB activity correlates with growth, angiogenesis, and metastasis of human melanoma cells in nude mice.

The purpose of this study was to determine the role of nuclear factor (NF)-kappaB/relA activity in the induction of angiogenesis and production of metastasis by human melanoma cells. Highly metastatic melanoma variant cells expressed high levels of constitutive NF-kappaB activity. Transfection of highly metastatic human melanoma variant cells with a dominant-negative mutant inhibitor of nuclear factor-kappaB alpha (Ikappabeta alpha) expression vector (Ikappabeta alphaM) decreased the level of constitutive NF-kappaB activity, inhibited s.c. tumor growth, and prevented lung metastasis in nude mice. Furthermore, the slow-growing s.c. tumors formed by the IkappaB alphaM-transfected cells exhibited a decrease in microvessel density (angiogenesis), which correlated with a decrease in the level of interleukin-8 expression. Collectively, these results demonstrate that NF-kappaB/reLA activity significantly contributes to tumorigenicity, angiogenesis, and metastasis of human melanoma cells implanted in nude mice.

Animals↗
PubMed2000

Regulation of disease-progression genes in human gastric carcinoma cells by interleukin 8.

The expression of interleukin 8 (IL-8) by human gastric carcinomas directly correlates with tumor vascularity and disease progression. To determine whether IL-8 can act in an autocrine manner to regulate the expression of other disease-progression genes, we examined the expression of IL-8 receptors IL-8RA (CXCR1) and IL-8RB (CXCR2) in six different human gastric carcinoma cell lines and 38 surgical specimens of human gastric carcinomas. All of the gastric carcinoma cell lines expressed mRNA and protein for IL-8RA and IL-8RB protein. In all surgical specimens, the majority of the tumor cells and small vessel endothelial cells stained positive for IL-8RA and IL-8RB protein. In vitro treatment of human gastric cancer MKN-1 cells with exogenous IL-8 enhanced the expression of epidermal growth factor receptor, type IV collagenase (metalloproteinase-9), vascular endothelial growth factor, and IL-8 mRNA. In contrast, treatment with exogenous IL-8 decreased expression of E-cadherin mRNA. IL-8 treatment increased invasive capacity of MKN-1 cells, which was associated with activity of metalloproteinase-9. Collectively, these results demonstrate that human gastric carcinoma cells express receptors for IL-8 and that IL-8 may play a role in the progressive growth of human gastric carcinoma by autocrine/paracrine mechanisms.

Cell Membrane↗
PubMed1999

Hypoxia-induced elevation in interleukin-8 expression by human ovarian carcinoma cells.

The expression level of interleukin-8 (IL-8) directly correlates with the progression of human ovarian carcinomas implanted into the peritoneal cavity of nude mice, but the mechanism of induction is unknown. Because hypoxia induces expression of vascular endothelial growth factor/vascular permeability factor, which, like IL-8, is an angiogenesis-regulating molecule, we determined whether hypoxic conditions could regulate the expression of IL-8. Surgical specimens of human ovarian carcinomas were prepared for immunohistochemical and in situ hybridization analysis. Elevated levels of IL-8 mRNA and protein were found in tumor cells adjacent to necrotic zones. In vitro exposure of human ovarian carcinoma cell lines SKOV3 i.p.1 and Hey-A8 to hypoxia resulted in a time-dependent increase in steady-state levels of IL-8 mRNA (Northern blot) and in increased production and secretion of IL-8 protein (ELISA). Hypoxia-mediated transient induction of IL-8 expression could be ascribed to both an increase in IL-8 mRNA stability and transcriptional activation of the IL-8 gene promoter. Detailed functional analysis of the IL-8 promoter revealed that the sequence between -133 and -98 bp relative to the transcription initiation site was primarily responsible for IL-8 gene transcriptional activation by hypoxia. Point-mutated luciferase reporter studies indicated that AP-1 and NF-kappaB-like factor binding elements were mainly responsible for hypoxia-induced increase in IL-8 gene expression in human ovarian cancer cells, and that IL-8 transcription activation by hypoxia required the cooperation of NF-kappaB and AP-1 binding sites.

Binding, Competitive↗