Phase I evaluation of recombinant tumor necrosis factor given in combination with recombinant interferon-gamma

Antisense oligonucleotides against TNFR1 prevent toxicity of TNF/IFNγ treatment in mouse tumor models

Tumor necrosis factor (TNF) has remarkable antitumor effects, but its systemic therapeutic use is prevented by its lethal inflammatory effects. TNFR1 (P55) is essential for both the antitumor and toxic effects because both of them are absent in P55-deficient mice. In previous work we demonstrated that P55+/- mice are completely resistant to TNF toxicity, while the antitumor effects induced by TNF combined with interferon gamma (IFNγ) remain fully functional in these mice. Hence, a high dose of TNF/IFNγ has an excellent therapeutic potential when P55 levels are reduced, because TNF induces tumor regression without systemic toxicity. Here, we provide proof of principle for therapeutic application of this approach by using antisense oligonucleotides (ASOs). Treatment of mice with ASOs targeting P55 resulted in a strong reduction in P55 protein levels in liver, small intestine and blood mononuclear cells. This P55 downregulation was associated with significant protection of mice against acute TNF toxicity as measured by hypothermia, systemic inflammation and lethality. This treatment also protected mice against toxicity of TNF/IFNγ treatment in several cancer models: B16Bl6, Lewis lung carcinoma and a lung colony model. Our results confirm the therapeutic value of this strategy, which could lead to the development of a safer and more effective TNF/IFNγ antitumor therapy.

Safe TNF-based antitumor therapy following p55TNFR reduction in intestinal epithelium

TNF has remarkable antitumor activities; however, therapeutic applications have not been possible because of the systemic and lethal proinflammatory effects induced by TNF. Both the antitumor and inflammatory effects of TNF are mediated by the TNF receptor p55 (p55TNFR) (encoded by the Tnfrsf1a gene). The antitumor effect stems from an induction of cell death in tumor endothelium, but the cell type that initiates the lethal inflammatory cascade has been unclear. Using conditional Tnfrsf1a knockout or reactivation mice, we found that the expression level of p55TNFR in intestinal epithelial cells (IECs) is a crucial determinant in TNF-induced lethal inflammation. Remarkably, tumor endothelium and IECs exhibited differential sensitivities to TNF when p55TNFR levels were reduced. Tumor-bearing Tnfrsf1a⁺⁺/⁻ or IEC-specific p55TNFR-deficient mice showed resistance to TNF-induced lethality, while the tumor endothelium remained fully responsive to TNF-induced apoptosis and tumors regressed. We demonstrate proof of principle for clinical application of this approach using neutralizing anti-human p55TNFR antibodies in human TNFRSF1A knockin mice. Our results uncover an important cellular basis of TNF toxicity and reveal that IEC-specific or systemic reduction of p55TNFR mitigates TNF toxicity without loss of antitumor efficacy.

Interactions between rnacrophage cytokines and eicosanoids in expression of antitumour activity

Cytokines and eicosanoid products of macrophages play an essential role in expression of antitumour activity of macrophages either in a cell-to-cell contact system between the effector and the target cell or as cell-free soluble products. In this review the relationship between three main monokines, namely TNF-α, IL-1 and IL-6 and the interrelationship between these monokines and eicosanoids (PGE₂, PGI₂, LTB₄, LTC₄) in their production and in expression of antitumour activity is discussed. Emphasis is given to the effect of tumour burden on production of the monokines and of the eicosanoids and on the production of these compounds by the tumour cells. Finally, the therapeutic implications drawn from animal studies and clinical trials is discussed.

Systemic use of tumor necrosis factor alpha as an anticancer agent

Tumor necrosis factor-α (TNF-α) has been discussed as a potential anticancer agent for many years, however initial enthusiasm about its clinical use as a systemic agent was curbed due to significant toxicities and lack of efficacy. Combination of TNF-α with chemotherapy in the setting of hyperthermic isolated limb perfusion (ILP), has provided new insights into a potential therapeutic role of this agent. The therapeutic benefit from TNF-α in ILP is thought to be not only due to its direct anti-proliferative effect, but also due to its ability to increase penetration of the chemotherapeutic agents into the tumor tissue. New concepts for the use of TNF-α as a facilitator rather than as a direct actor are currently being explored with the goal to exploit the ability of this agent to increase drug delivery and to simultaneously reduce systemic toxicity.

This review article provides a comprehensive overview on the published previous experience with systemic TNF-α. Data from 18 phase I and 10 phase II single agent as well as 18 combination therapy studies illustrate previously used treatment and dose schedules, response data as well as the most prominently observed adverse effects. Also discussed, based on recent preclinical data, is a potential future role of systemic TNF-α in combination with liposomal chemotherapy to facilitate increased drug uptake into tumors.

Interleukin-1 beta-induced anorexia is reversed by ghrelin

Interleukins, in particular interleukin-1beta (IL-1beta), reduce food intake after peripheral and central administration, which suggests that they contribute to anorexia during various infectious, neoplastic, and autoimmune diseases. On the other hand, ghrelin stimulates food intake by acting on the central nervous system (CNS) and is considered an important regulator of food intake in both rodents and humans. In the present study, we investigated if ghrelin could reverse IL-1beta-induced anorexia. Intracerebroventricular (i.c.v.) injection of 15, 30 or 45 ng/microl of IL-1beta caused significant suppression of food intake in 20 h fasting animals. This effect lasted for a 24h period. Ghrelin (0.15 nmol or 1.5 nmol/microl) produced a significant increase in cumulative food intake in normally fed animals. However, it did not alter food intake in 20 h fasting animals. Central administration of ghrelin reduced the anorexic effect of IL-1beta (15 ng/microl). The effect was observed 30 min after injection and lasted for the next 24h. This study provides evidence that ghrelin is an orexigenic peptide capable of antagonizing IL-1beta-induced anorexia.

New approaches for mesothelioma: biologics, vaccines, gene therapy, and other novel agents

Although malignant mesothelioma is not a classically immunogenic cancer, there is abundant evidence for immune recognition. The relative ease of obtaining tumor tissue makes mesothelioma ideal for studying surrogate biomarkers such as lymphocytic infiltration or expression of transduced genes. There is evidence that malignant mesothelioma patients as well as asbestos-exposed persons without mesothelioma have impaired immune responsiveness. Substantial progress has been made in animal models using several biological and immunological techniques, but clinical application has been problematic. Systems studied have included lysis by interleukin-2 (IL-2)-activated lymphokine-activated killer (LAK) cells, tumor necrosis factor-alpha (TNF-alpha), a p16-expressing adenovirus vector, suicide gene therapy using the herpes simplex virus-tyrosine kinase (HSV-tk) followed by ganciclovir, and immunomodulatory gene therapy with IL-2, IL-4, interferon-gamma (IFN-gamma), IFN-alpha, TNF-alpha, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6, and IL-1beta transfected into tumors. Vaccinia virus has been studied as a vector for cytokine gene transfer. Suicide gene therapy has been combined with a tumor vaccine. The University of Western Australia is initiating a pilot study of autologous vaccination in malignant mesothelioma. Novel agents under study include the angiogenesis inhibitors SU5416, bevacizumab, and thalidomide. ZD1839, an orally administered, highly selective inhibitor of the epidermal growth factor receptor (EGFR) tyrosine kinase, is being tested in a phase II trial. Since platelet-derived growth factor (PDGF) is thought to be an autocrine growth factor for mesothelioma STI-571 (Gleevec; Novartis, Basel, Switzerland), a highly selective inhibitor of the PDGF receptor tyrosine kinase, is being tested in a phase II trial. The development of more active cytotoxic combinations in this disease should facilitate further studies of chemoimmunotherapy. It seems likely that no single treatment modality will be effective by itself.

Elevated, sustained peroxynitrite levels as the cause of chronic fatigue syndrome

The etiology of chronic fatigue syndrome (CFS) has been both obscure and highly contentious, leading to substantial barriers to both clear diagnosis and effective treatment. I propose here a novel hypothesis of CFS in which either viral or bacterial infection induces one or more cytokines, IL-1beta IL-6, TNF-alpha and IFN-gamma. These induce nitric oxide synthase (iNOS), leading to increased nitric oxide levels. Nitric oxide, in turn, reacts with superoxide radical to generate the potent oxidant peroxynitrite. Multiple amplification and positive feedback mechanisms are proposed by which once peroxynitrite levels are elevated, they tend to be sustained at a high level. This proposed mechanism may lower the HPA axis activity and be maintained by consequent lowered glucocorticoid levels. Similarities are discussed among CFS and autoimmune and other diseases previously shown to be associated with elevated peroxynitrite. Multiple pharmacological approaches to the treatment of CFS are suggested by this hypothesis.

Molecular design of hybrid tumour necrosis factor-alpha. II: The molecular size of polyethylene glycol-modified tumour necrosis factor-alpha affects its anti-tumour potency

To design hybrid tumour necrosis factor-alpha (TNF-alpha) applicable to systemic anti-tumour therapeutic use, we assessed the relationships among the molecular size of hybrid TNF-alpha, in vitro bioactivity and in vivo anti-tumour potency. Natural human TNF-alpha was covalently modified with polyethylene glycol (PEG) of various number-average molecular weights (Mn = 2000, 5000, 12,000). The in vitro bioactivity of PEG-modified TNF-alpha s decreased with an increase in the degree of PEG modification, irrespective of the molecular weight of PEG. This decrease in the specific bioactivity markedly increased with an increase in the molecular weight of the attached PEG. The in vivo anti-tumour effects of the hybrid TNF-alpha s with a molecular size from 100 to 110 kDa, which had more than 50% of specific bioactivity of native TNF-alpha, were significantly superior to other PEG-TNF-alpha s. These hybrid TNF-alpha s showed over ten times greater anti-tumour effects than native TNF-alpha. Thus, the molecular size, which was determined by the degree of PEG modification and PEG molecular weight, influences the specific activity and anti-tumour effects of hybrid TNF-alpha.

[Nephropathies caused by interferon alpha: apropos of 2 cases]

Two cases reports of interferon alpha-associated nephropathy are reported. The first observation is a membranoproliferative glomerulonephritis and the second a renal microangiopathy. The different cases in the literature are reviewed and the pathophysiology is discussed.

Dipyridamole combined with tumor necrosis factor-alpha enhances inhibition of proliferation in human tumor cell lines

In the search for cytokines whose antiproliferative action could be enhanced by combination with dipyridamole, 2,6-bis(diethanolamino)-4,8-dipiperidinopyrimido[5,4-d]pyrim idine, the combination of tumor necrosis factor-alpha (TNF-alpha) with this agent was evaluated in various human tumor cell lines. Inhibition of the proliferation of human melanoma cell lines MM-1CB and HMV-1 by TNF-alpha (1-10(2) U/ml) was enhanced in culture dishes by combination treatment with dipyridamole (0.1-10 microM). The enhancement effect was also detected in other tumor cell lines: T98 (glioma), SCC-1CB (squamous cell carcinoma), HAC-2 (ovarian clear-cell carcinoma), HLE (hepatoma), HEC-1 (endometrial adenocarcinoma) and HOC-21 (ovarian serous cystadenocarcinoma). The incorporation of [14C]amino acids and [3H]uridine into acid-insoluble cell materials in the combination-treated cells was not significantly different from that in cells treated with TNF-alpha or dipyridamole. However, the incorporation of [3H]thymidine was specifically inhibited in all cell lines examined after more than 12 h of the TNF-alpha and dipyridamole combination treatment, although neither agent alone inhibited this incorporation. On the other hand, the growth of tumors induced by the injection of MM-1CB and HMV-1 cells into nude mice was more markedly inhibited by the subcutaneous administration of TNF-alpha in combination with orally administered dipyridamole than by either agent alone. The results presented suggested that dipyridamole is beneficial in assuring the effectiveness of anti-cancer cytokine therapy.

Cytokine combinations in immunotherapy for solid tumors: a review

The use of cytokines alone or in combination with other cytokines or cytotoxic drugs has had a profound effect upon widely metastatic disease in many cases. However, despite the encouraging results in early trials, there is much room for improvement. Few responses to these combinations are complete, and toxicity has in some cases been quite severe. Changes in dose, route, or schedule of administration of the drugs, or the development of cytokine analogs may lead to more efficacious and less toxic regimens. In addition, new cytokines such as interleukin(IL)-7 and IL-12 are currently under investigation for potential use in future immunotherapy trials. These prospects and the use of cytokine combinations are promising advances in the treatment of human cancer.

Adoptive immunotherapy of cancer: biological response modifiers and cytotoxic cell therapy

Immunotherapy has been developed for the treatment of metastatic cancers refractory to conventional therapies. Immunotherapy utilizes immune cells and/or biological response modifiers (BRMs) to induce an anti-tumor response mediated by the patient's immune system. BRMs, including lymphokines and cytokines, are used as single agents or in combination for cancer therapy. Some BRMs, particularly interleukin 2 (IL-2), can activate and expand in vitro lymphocytes with anti-tumor reactivity which will be adoptively transferred to the patient. To enhance the therapeutic effect of immunotherapy, gene therapy is currently under investigation and involves the insertion of cytokine genes in immune cells or in tumor cells. The development and future of cancer immunotherapy will be discussed in this review.

Evaluation of basic procedures for adoptive immunotherapy for gastric cancer

Peripheral blood lymphocytes (PBL) of gastric cancer patients in advanced stages showed lymphokine activated killer (LAK) activities comparable to those of healthy donors, suggesting potential applicability of LAK cells induced from PBL stimulated with recombinant interleukin-2 (rIL-2) in adoptive immunotherapy (AIT) for gastric cancer. In order to generate a large number of LAK cells from PBL, lymphocytes were cultured with both rIL-2 and phytohemagglutinin (PHA). In this culture, the numbers of cells increased to a greater extent than those in culture with rIL-2 alone but cytotoxic activity did not augment, thus suggesting that this procedure would not afford sufficient clinical effects. On the other hand, a large number of LAK cells with high anti-tumor activities were efficiently induced from spleen cells of the patients by culture of rIL-2; hence clinical usefulness of these LAK cells is anticipated. In regional lymph node lymphocytes (RLNL) cultured with rIL-2, the cytotoxic activities were lower than in those induced in PBL, and a characteristic increase of CD8 + CD11 + suppressor T cells was observed after incubation with rIL-2. Nevertheless, an increase of CD4 + 4B4 + helper inducer T cells was also observed in RLNL after the culture with rIL-2. Furthermore, high cytotoxic activities were induced in RLNL in some cases in which metastasis to the regional lymph nodes was not detected. When gastric cancer patients were pretreated with biological response modifiers (BRM), especially with Lentinan, LAK cells from PBL showed higher NK and LAK activities as compared with those of patients without BRM pretreatment.