Inducer-specific bidirectional regulation of endothelial interleukin-8 production by thalidomide

Thalidomide: mechanisms of action

The classification of thalidomide as an orphan drug with anti-inflammatory actions has led to its off-label use in conditions refractory to other medications. Although the observed clinical effects of thalidomide suggest it to have immunomodulatory capabilities, the mechanism of action is unclear. Here we review both the positive and negative studies of thalidomide at the bench in order to improve our understanding of the possible mechanisms of this drug in treating a variety of diseases at the bedside. Studies on the effects of thalidomide on the innate and adaptive immune system as well as tumorigenesis and angiogenesis are discussed.

Thalidomide suppressed interleukin-6 but not tumor necrosis factor-alpha in volunteers with experimental endotoxemia

An early rationale for using thalidomide to treat erythema nodosum leprosum had been based on some reports that it suppresses tumor necrosis factor-alpha (TNF-alpha). However, in vivo and in vitro studies have yielded variable results, having shown that thalidomide can either enhance or suppress TNF-alpha. Since the course of circulating cytokines like TNF-alpha after infusion of endotoxin into volunteers is reproducible and characteristic, we investigated the effect of thalidomide on endotoxin-induced synthesis of TNF-alpha, interleukin (IL)-6, and IL-8. The cytokine response from 18 placebo-treated subjects who had undergone the endotoxin challenge were pooled with a placebo-treated subject from the current study and were compared with 4 subjects who received thalidomide (100 mg) every 6 h for 5 doses before endotoxin challenge. Thirty minutes after the last dose of thalidomide or placebo, volunteers were infused with 4-ng/kg endotoxin. Plasma was collected and assayed for cytokines by enzyme-linked immunosorbent assay. Endotoxin evoked the synthesis of the cytokines in all volunteers. The peak response for TNF-alpha was 1.5 h, 2.5 h for IL-8, and 3.0 h for IL-6. Thalidomide did not significantly delay the release of cytokines into the circulating blood. At the peak response, thalidomide reduced the concentration of the cytokines in the plasma. Using the area under the dose response curve (AUC(0 to 24) h), thalidomide reduced the AUC for IL-6 by 56%, for IL-8 by 30%, and TNF-alpha by 32%. In this model, thalidomide did not suppress TNF-alpha or IL-8, but it did suppress IL-6 at 4-h postinfusion with lipopolysaccharide (P=0.004), at 6 h (P=0.014), at 12 h (P=0.001), and at 16 h (P=0.012).

Thalidomide in multiple myeloma

Multiple myeloma is an incurable bone marrow cancer, the treatment of which is notoriously difficult. Only modest advances have been achieved using complex polychemotherapeutic regimens, transplant strategies and supportive therapy. In 1999, when new drugs for myeloma were urgently needed, thalidomide was introduced and opened up a completely new line of therapy for the disease. Although the mechanism of action is not yet completely understood, thalidomide has demonstrated efficacy in patients with refractory, relapsed myeloma, even in late-stage cases. This article reviews the current knowledge of thalidomide in myeloma treatment, focusing especially on the possible mechanisms of action, clinical results and adverse events of this drug.

Thalidomide : mécanismes d'action et indications en hématologie

Purpose. - Thalidomide, a major teratogen drug, was rehabilitated mainly in malignant hemopathy. Current knowledge and key points. - Thalidomide-mechanisms of action are well known, multiple, they combine immunomodulatory, antiangiogenic properties, and the modulation of cytokines, particularly tumour necrosis factor-alpha. Multiple trials are ongoing, however, the main indication remain multiple myeloma with a response rate of 30% in relapsed patients. Future prospects and projects. - New structural analogues of the thalidomide which priviligiate some of the thalidomide-specific mechanisms of action, the selected cytokine inhibitory drugs (SelCIDS) and the immunomodulatory drugs (IMiDs) family are under evaluation. The IMiDs, which mechanism is based on stimulation of T lymphopoiesis rather than inhibition of tumour necrosis factor-alpha, are under clinical trials in multiple myeloma with interesting results.

Tumor-associated macrophages: the double-edged sword in cancer progression

PURPOSE

Inflammation plays a critical role in cancer progression. In this study we investigate the pro-tumorigenic activities and gene expression profiles of lung cancer cells after interaction with macrophages.

MATERIALS AND METHODS

We measured intratumoral microvessel counts and macrophage density in 41 lung cancer tumor specimens and correlated these with the patients' clinical outcome. The interaction between macrophages and cancer cell lines was assessed using a transwell coculture system. The invasive potential was evaluated by in vitro invasion assay. The matrix-degrading activity was assayed by gelatin zymography. The microarray was applied to a large-scale analysis of the genes involved in the interaction, as well as to monitor the gene expression profiles of lung cancer cells responding to anti-inflammatory drugs in cocultures.

RESULTS

The macrophage density positively correlated with microvessel counts and negatively correlated with patient relapse-free survival (P < .05). After coculture with macrophages, lung cancer cell lines exhibited higher invasive potentials and matrix-degrading activities. We identified 50 genes by microarray that were upregulated more than two-fold in cancer cells after coculture. Northern blot analyses confirmed some gene expression such as interleukin-6, interleukin-8, and matrix metalloproteinase 9. The two-dimensional hierarchical clustering also demonstrated that the gene expression profiles of lung cancer cells responding to various anti-inflammatory drugs in cocultures are distinct.

CONCLUSION

The interaction of lung cancer cells and macrophages can promote the invasiveness and matrix-degrading activity of cancer cells. Our results also suggest that a great diversity of gene expression occurs in this interaction, which may assist us in understanding the process of cancer metastasis.

Effects of thalidomide on parameters involved in angiogenesis: an in vitro study

In an attempt to elucidate the mechanism(s) of action of thalidomide, a reportedly antiangiogenic molecule recently tested in the treatment of relapsing malignant gliomas, we performed an in vitro study on the following parameters: (a) effect of thalidomide on proliferation of endothelial cells; (b) effect of thalidomide on expression of alpha(v)beta3 integrin on the surface of endothelial cells; (c) effect of thalidomide on the release by endothelial cells of MMP-2, IL-8 and TNF-alpha. The results show that thalidomide inhibits endotelial cell proliferation induced by bFGF and VEGF, more so if the cells are grown on vitronectin; moreover, treatment with thalidomide reduces the release of MMP-2 and IL-8 by endothelial cells, suggesting a further pathway for the antiangiogenic activity of drug. On the other hand, thalidomide does not modify expression of alpha(v)beta3 on endothelial cells.

Thalidomide in cancer treatment: a potential role in the elderly?

There is increased interest in the treatment of cancer with thalidomide because of its antiangiogenic, immunomodulating and sedative effects. In animal models, the antitumour activity of thalidomide is dependent on the species, route of administration and coadministration of other drugs. For example, thalidomide has shown antitumour effects as a single agent in rabbits, but not in mice. In addition, the antitumour effects of the conventional cytotoxic drug cyclophosphamide and the tumour necrosis factor inducer 5,6-dimethylxanthenone-4-acetic acid (DMXAA) were found to be potentiated by thalidomide in mice bearing colon 38 adenocarcinoma tumours. Further studies have revealed that thalidomide upregulates intratumoral production of tumour necrosis factor-alpha 10-fold over that induced by DMXAA alone. Coadministration of thalidomide also significantly reduced the plasma clearance of DMXAA and cyclophosphamide. All these effects of thalidomide may contribute to the enhanced antitumour activity. Recent clinical trials of thalidomide have indicated that it has minimal anticancer activity for most patients with solid tumours when used as a single agent, although it was well tolerated. However, improved responses have been reported in patients with multiple myeloma. Palliative effects of thalidomide on cancer-related symptoms have also been observed, especially for geriatric patients with prostate cancer. Thalidomide also eliminates the dose-limiting gastrointestinal toxic effects of irinotecan. There is preliminary evidence indicating that the clearance of thalidomide may be reduced in the elderly. The exact role of thalidomide in the treatment of cancer and cancer cachexia in the elderly remains to be elucidated. However, it may have some value as part of a multimodality anticancer therapy, rather than as a single agent.

Theoretical basis for the activity of thalidomide

The revival of thalidomide began shortly after the drug was withdrawn from the market because of its teratogenic properties. Therapeutic effects of thalidomide were found accidentally in leprosy patients with erythema nodosum leprosum (ENL). Subsequent research widened the understanding of the activity of thalidomide, and with improved methodology and the augmented background knowledge of immunology it was possible to interpret the properties of thalidomide more coherently. Effects on tumour necrosis factor-alpha (TNFalpha) release play an important role in the ability of thalidomide to affect the immune system. Alteration of synthesis and release of cytokines such as interleukin (IL)-1, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12 and interferon-gamma is involved in the complex mechanisms of thalidomide. Thalidomide targets leucocytes, endothelial cells and keratinocytes, affecting them in a different manner and at different cellular levels. Changes in the density of adhesion molecules alter leucocyte extravasation and the inflammatory response in the tissue involved. Several mechanisms for the teratogenic action of thalidomide are currently under review, but this mode of action of the drug still remains unclear and we review evidence-based hypotheses for the teratogenicity of thalidomide. Thalidomide shows significant clinical impact in several diseases such as ENL in lepromatous leprosy, chronic graft-versus-host disease, systemic lupus erythematosus, sarcoidosis, aphthous lesions in HIV infection, wasting syndrome in chronic illness, inflammatory bowel disease, multiple myeloma and some solid tumours. In 1998 the US Food and Drug Administration approved thalidomide exclusively for the treatment of ENL, and strict conditions were stipulated for its use in order to prevent teratogenic adverse effects. However, despite the promising findings of thalidomide at the molecular level, namely its anti-TNFalpha properties and its intercalation with DNA, and activity in clinical trials, there is still a great need for more intensive research.

Thalidomide impairment of trinitrobenzene sulphonic acid-induced colitis in the rat - role of endothelial cell-leukocyte interaction

1. Immune response-modulating drugs such as thalidomide may be of therapeutic value in the treatment of chronic inflammatory bowel diseases including Crohn's disease (CD). In the present study, we have investigated whether thalidomide exerts this effect by impairing endothelial cell-leukocyte interaction through down-regulation of the expression of pro-inflammatory gene products in these cells. 2. Transient CD-like colitis was induced in male Wistar rats by single enema with trinitrobenzene sulphonic acid (TNBS) in ethanol followed by macroscopic scoring, histology, intravital microscopy, RT - PCR and immunohistochemistry (IHC) analyses. Thalidomide or its analogue supidimide were administered in olive oil by intragastric instillation 6 h prior to the induction of colitis and then daily for one week. 3. Both thalidomide and supidimide (200 mg kg(-1) d(-1)) significantly attenuated TNBS-induced colitis as compared to vehicle-treated control animals (44 and 37% inhibition, respectively), and this effect persisted for 7 days post cessation of thalidomide treatment (46% inhibition). 4. Moreover, thalidomide significantly reduced leukocyte sticking to postcapillary venular endothelial cells in the submucosa (by 45%), improved functional capillary density and perfusion, and attenuated endothelial interleukin-8 expression, as judged by IHC analysis. According to RT - PCR analysis, both thalidomide and supidimide also significantly reduced vascular cell adhesion molecule-1 mRNA expression in the affected part of the descending colon. 5. These findings suggest that thalidomide and one of its derivatives impairs CD-like TNBS-induced colitis in the rat by down-regulating endothelial adhesion molecule and chemokine expression and, as a consequence, the interaction of these cells with circulating leukocytes.