A phase 1 trial of recombinant human IL-21 in combination with cetuximab in patients with metastatic colorectal cancer.

Background: Pre-clinical data indicate enhanced anti-tumour activity when combining recombinant human interleukin-21 (rIL-21), a class 1 cytokine, with cetuximab, a monoclonal antibody, targeting the epidermal growth factor receptor. This phase 1 trial assessed the safety and tolerability of escalating doses of rIL-21 in combination with cetuximab in chemo-naïve patients with stage IV colorectal cancer.

Patients And Methods: Sequential cohorts of PS 0-1, asymptomatic patients, were treated weekly with cetuximab 250 mg m(-2) intravenously (i.

Immunolymphoscintigraphy for metastatic sentinel nodes: test of a model.

Aim. To develop a method and obtain proof-of-principle for immunolymphoscintigraphy for identification of metastatic sentinel nodes. Methods.

Non-invasive imaging of combretastatin activity in two tumor models: Association with invasive estimates.

Introduction: The efficacy of the vascular disrupting agent combretastatin A-4 phosphate (CA4P) depends on several factors including tumor size, nitric oxide level, interstitial fluid pressure, and vascular permeability. These factors vary among tumor types. The aim of this study was to investigate all these factors in two tumor models that respond differently to CA4P.

Clinical and biological efficacy of recombinant human interleukin-21 in patients with stage IV malignant melanoma without prior treatment: a phase IIa trial.

Purpose: Human interleukin-21 (IL-21) is a class I cytokine that mediates activation of CD8(+) T cells, natural killer (NK) cells, and other cell types. We report final clinical and biological results of a phase II study of recombinant human IL-21 (rIL-21) in patients with metastatic melanoma.

Experimental Design: Open-label, single-arm, two-stage trial.

Hypoxia-induced secretion of macrophage migration-inhibitory factor from MCF-7 breast cancer cells is regulated in a hypoxia-inducible factor-independent manner.

The cytokine MIF is over-expressed in tumors and is associated with tumor proliferation, angiogenesis and metastasis. Hypoxia, a hallmark feature of tumors, increases MIF expression from tumor cells. We examined the role of hypoxia-inducible transcription factors on MIF secretion from MCF-7 breast carcinoma cells.

Aerobic glycolysis in cancers: implications for the usability of oxygen-responsive genes and fluorodeoxyglucose-PET as markers of tissue hypoxia.

The hypoxia-responsiveness of the glycolytic machinery may allow pretreatment identification of hypoxic tumors from HIF-1 targets (e.g., Glut-1) or [18F]-fluorodeoxyglucose positron emission tomography but results have been mixed.

Increase in neurogenesis and behavioural benefit after chronic fluoxetine treatment in Wistar rats.

Objective: Disturbances in hippocampal neurogenesis may be involved in the pathophysiology of depression and it has been argued that an increase in the generation of new nerve cells in the hippocampus is involved in the mechanism of action of antidepressants.

Materials And Methods: Adult Wistar rats were treated with fluoxetine (10 mg/kg) 1 h, daily for 5 (subchronic) or 28 days (chronic) before the Novelty Suppressed Feeding test was performed. Cell proliferation and neurogenesis were analysed using the markers 5-bromo-deoxy-2'-uridine, Ki-67, and doublecortin.

Interleukin-21 signaling: functions in cancer and autoimmunity.

Interleukin-21 (IL-21) is a cytokine with structural and sequence homology to IL-2 and IL-15, yet possesses several biological properties distinct from these cytokines. IL-21 is produced mainly by activated CD4(+) T cells and natural killer T cells and mediates its activity by binding to the IL-21 receptor (IL-21R), consisting of an IL-21-specific alpha chain (IL-21Ralpha; JAK/STAT) that heterodimerizes with the common gamma chain (CD132). Intracellular signaling occurs through the Janus-activated kinase/signal transducer and activator of transcription pathways.

Early effects of combretastatin-A4 disodium phosphate on tumor perfusion and interstitial fluid pressure.

Combretastatin-A4 disodium phosphate (CA4DP) is a vascular-disruptive agent that causes an abrupt decrease in tumor blood flow. The direct actions of CA4DP include increases in vascular permeability and destabilization of the endothelial cytoskeleton, which are thought to contribute to occlusion of the tumor vasculature. It has been proposed that increased permeability causes a transient increase in interstitial fluid pressure (IFP), which in turn could collapse intratumoral blood vessels.

Interleukin 21 therapy increases the density of tumor infiltrating CD8+ T cells and inhibits the growth of syngeneic tumors.

Interleukin (IL)-21 is a recently discovered cytokine in early clinical development, which has shown anti-tumor activity in various animal models. In the present study, we examine the anti-tumor activity of IL-21 protein therapy in two syngeneic tumor models and its effect on the density of tumor infiltrating T cells. We treated mice bearing established subcutaneous B16 melanomas or RenCa renal cell carcinomas with intraperitoneal (i.

Angiopoietin-4 inhibits angiogenesis and reduces interstitial fluid pressure.

Angiopoietins (Ang) are involved in the remodeling, maturation, and stabilization of the vascular network. Ang-4 was discovered more recently; thus, its effect on angiogenesis and its interplay with other angiogenic factors have not been equivocally established. The role of Ang-4 in angiogenesis was tested in Matrigel chambers implanted into the subcutaneous space of nude mice.

How few cancer cells can be detected by positron emission tomography? A frequent question addressed by an in vitro study.

Purpose: Positron emission tomography (PET) has gained widespread use in cancer diagnosis and treatment, but how many malignant cells are required for a tumour to be detected by PET?

Methods: Three human cancer cell lines [glioblastoma and two subtypes of small cell lung cancer (SCLC)] in concentrations from 10(4) to 10(7) were seeded on six-well plates or plastic tubes and treated with [(18)F]fluorodeoxy-glucose (FDG) in vitro. FDG retention was measured in a PET/CT scanner and in a calibrated well counter. The clinical situation was simulated using a cylinder phantom with a background concentration of FDG.

Interactions between HIF-1 and Jab1: balancing apoptosis and adaptation. Outline of a working hypothesis.

When cells experience hypoxia, they either die by apoptosis or adapt to the hypoxic conditions by a series of compensatory mechanisms. Hypoxia inducible factor-1 (HIF-1) is a transcription factor involved in both processes, but the exact mechanisms regulating whether the cells survive (adapt) or perish by apoptosis are largely unknown. We hypothesize that the balancing between apoptosis and adaptation is governed by a triangular feedback system involving the alpha-subunit of HIF-1, p53, and jun activating binding protein 1 (Jab1).

Antitumor efficacy of a urokinase activation-dependent anthrax toxin.

Previously, we have generated a potent prodrug consisting of modified anthrax toxins that is activated by urokinase plasminogen activator (uPA). The cytotoxicity of the drug, PrAg-U2 + FP59, is dependent on the presence of receptor-associated uPA activity. Local intradermal administration of PrAg-U2 + FP59 adjacent to the tumor nodules in mice with transplanted solid tumors had a potent antitumor effect.

Combining etoposide and dexrazoxane synergizes with radiotherapy and improves survival in mice with central nervous system tumors.

Purpose: The treatment of patients with brain metastases is presently ineffective, but cerebral chemoradiotherapy using radiosensitizing agents seems promising. Etoposide targets topoisomerase II, resulting in lethal DNA breaks; such lesions may increase the effect of irradiation, which also depends on DNA damage. Coadministration of the topoisomerase II catalytic inhibitor dexrazoxane in mice allows for more than 3-fold higher dosing of etoposide.

Augmenting tumor sensitivity to topotecan by transient hypoxia.

We examined how the effect of topotecan is modulated by transient hypoxia in three different tumor lines, Lewis lung carcinoma (LLC), U87 human glioblastoma and DMS273 human small cell lung cancer. Four groups of tumor bearing mice were treated with saline or a single dose of topotecan, immediately followed by 6-h or 72-h exposure to a hypoxic environment (10% O(2)) or normal air. Topotecan + hypoxia resulted in significantly greater suppression of tumor growth than normoxic topotecan or hypoxia alone.

Expression of YKL-40 by peritumoral macrophages in human small cell lung cancer.

YKL-40 is a 40 kDa protein with possible involvement in tissue remodeling, cell proliferation and angiogenesis. Elevated serum YKL-40 levels in patients with metastatic cancers (including small cell lung cancer (SCLC)) are associated with poor prognosis. The aim of this study was to identify the cellular source of YKL-40 in SCLC patient biopsies and in a panel of 20 human SCLC lines cultured in vitro and in vivo in nude mice.

Regulation of YKL-40 expression during genotoxic or microenvironmental stress in human glioblastoma cells.

YKL-40 is a 40 kDa secreted glycoprotein belonging to the family of 'mammalian chitinase-like proteins', but without chitinase activity. YKL-40 has a proliferative effect on fibroblasts, chondrocytes and synoviocytes, and chemotactic effect on endothelium and vascular smooth muscle cells. Elevated YKL-40 levels are found in serum of patients with diseases characterized by inflammation, fibrosis and tissue remodeling.

Angiogenic synergy of bFGF and VEGF is antagonized by Angiopoietin-2 in a modified in vivo Matrigel assay.

A murine modification of the Matrigel chamber assay originally developed for use on rats is presented. This modified assay permits improved quantification due to subcutaneous Matrigel implants of constant shape and volume. We have quantitatively assessed the angiogenic potential of the growth factors basic fibroblast growth factor (bFGF), VEGF, and Angiopoietin-2 (Ang-2) with special emphasis on their mutual interactions.

Differential regulation of VEGF, HIF1alpha and angiopoietin-1, -2 and -4 by hypoxia and ionizing radiation in human glioblastoma.

We examined how ionizing radiation (IR) delivered under either severe hypoxia (< 0.1% O2) or normoxia affects the expression of hypoxia inducible factor 1alpha (HIF-1alpha) and the angiogenic factors vascular endothelial growth factor (VEGF) and angiopoietins 1, 2 and 4 in U87 human glioblastoma cells. IR was delivered as single doses of 0, 2, 5, 10 and 20 Gy after 6-hr hypoxic incubation and in normoxic controls.

X-ray-induced oxidative stress: DNA damage and gene expression of HO-1, ERCC1 and OGG1 in mouse lung.

Effects of X-ray induced oxidative stress in mouse lungs were studied in terms of DNA damage and expression of antioxidant defense and DNA repair genes. Lung samples were collected immediately after, and 3, 6, and 22 h after irradiation with 1, 3, 10 or 30 Gy X-rays of the thorax. The levels of strand breaks (SB), formamidopyrimidine DNA glycosylase (FPG) and endonuclease III (ENDOIII) sensitive sites, detected by the comet assay, were increased dose-dependently immediately after irradiation, whereas 8-oxo-7,8-dihydro-2'-deoxyguanosine analyzed by HPLC-EC was unaltered, possibly due to a relatively high background level (2.

Arrested neuronal proliferation and impaired hippocampal function following fractionated brain irradiation in the adult rat.

The generation of new neurons in the adult mammalian brain has been documented in numerous recent reports. Studies undertaken so far indicate that adult hippocampal neurogenesis is related in a number of ways to hippocampal function.Here, we report that subjecting adult rats to fractionated brain irradiation blocked the formation of new neurons in the dentate gyrus of the hippocampus.

Expression and regulation patterns of hyaluronidases in small cell lung cancer and glioma lines.

Hyaluronan and hyaluronidases have been proposed to be involved in tumor angiogenesis and invasion. Three hyaluronidases, HYAL1, HYAL2 and HYAL3, are located at the chromosomal region 3p21. In most small cell lung cancer (SCLC) lines the 3p21 region is part of a homozygote or heterozygote deletion.

Improved effect of an antiangiogenic tyrosine kinase inhibitor (SU5416) by combinations with fractionated radiotherapy or low molecular weight heparin.

The effect of combining SU5416 with fractionated radiotherapy or with low molecular weight (LMW) heparin (dalteparin) was studied in U87 human glioblastoma xenografts in nude mice. SU5416 is antiangiogenic by a specific inhibition of the vascular endothelial growth factor receptor 2 (VEGFR-2), and heparins are assumed to bind VEGF. Both SU5416 (100 mg/kg every second day in 5 days) and 3 Gyx5 produced moderate, yet significant, growth inhibition.

Reduction of vascular and permeable regions in solid tumors detected by macromolecular contrast magnetic resonance imaging after treatment with antiangiogenic agent TNP-470.

Purpose: The availability of noninvasive techniques to detect the effects of antiangiogenic agents is critically important for optimizing treatment of cancer with these agents. Magnetic resonance imaging (MRI) is one such noninvasive technique that is routinely used clinically.

Experimental Design: In this study, we have evaluated the use of MRI of the intravascular contrast agent albumin-GdDTPA to detect the effects of the antiangiogenic agent TNP-470 on the vascular volume and permeability of the MatLyLu prostate cancer model.