Theoretical basis for the activity of thalidomide

Thalidomide-induced limb malformations: an update and reevaluation

Historically, thalidomide-induced congenital malformations have served as an important example of the enhanced susceptibility of developing embryos to chemical perturbation. The compound produced a wide variety of congenital malformations in humans, which were initially detected by an association with a relatively rare limb defect labeled phocomelia. Although true phocomelia in the most severe form is a transverse defect with intercalary absence of limb regions, it is proposed that thalidomide produces a longitudinal limb phenotype in humans under usual circumstances that can become transverse in severe cases with a preferential sensitivity of forelimb over hindlimb, preaxial over postaxial, and left more impacted than the corresponding non-autopod limb bones on the right. The thalidomide-induced limb phenotype in humans is described and followed by a hierarchical comparison with various laboratory animal species. Mechanistic studies have been hampered by the fact that only non-human primates and rabbits have malformations that are anatomically similar to humans. Included in this review are unpublished data on limb malformations produced by thalidomide in rhesus monkeys from experiments performed more than 50 years ago. The critical period in gestation for the induction of phocomelia may initiate prior to the development of the embryonic limb bud, which contrasts with other chemical and physical agents that are known to produce this phenotype. The importance of toxicokinetic parameters is reviewed including dose, enantiomers, absorption, distribution, and both non-enzymatic and enzymatic biotransformations. The limb embryopathy mechanism that provides a partial explanation of the limb phenotype is that cereblon binds to thalidomide creating a protein complex that ubiquitinates protein substrates (CRL4CRBN) that are not targets for the complex in the absence of the thalidomide. One of these neosubstrates is SALL4 which when mutated causes a syndrome that phenocopies aspects of thalidomide embryopathy. Other candidate neosubstrates for the complex that have been found in non-human species may contribute to an understanding of the limb defect including PLZF, p63, and various zinc finger transcription factors. It is proposed that it is important to consider the species-specificity of the compound when considering potential mechanistic pathways and that some of the more traditional mechanisms for explaining the embryopathy, such as anti-angiogenesis and redox perturbation, may contribute to a full understanding of this teratogen.

Efficacy of Thalidomide in Discoid Lupus Erythematosus: Insights into the Molecular Mechanisms

BACKGROUND

Thalidomide has been used successfully in a variety of chronic refractory inflammatory dermatological conditions with underlying autoimmune or infectious pathogenesis. It was first used for refractory discoid lupus erythematosus (DLE) in 1983 and has steadily grown since then.

METHOD

In this review, we describe the therapeutic benefits of thalidomide for DLE treatment and its biological properties. We explain how new discoveries in DLE pathogenesis are relevant to understand thalidomide's mechanism of action and the need to find an alternative safe drug with similar therapeutic effects.

SUMMARY

Thalidomide's efficacy in DLE patients is significant, with 80-90% reaching clinical remission according to different studies. However, thalidomide's use is still limited by serious adverse effects such as teratogenicity, neurotoxicity, and thrombosis. In addition, there is a frequent rate of relapse and many patients require a long-term low dose of thalidomide as maintenance. The achievement of clinical response within weeks is key to avoid irreversible DLE fibrotic sequelae, making it critical to introduce thalidomide earlier in the DLE treatment algorithm. Recently, microarray and miRNA screenings demonstrated a significant CD4+ T enrichment and T-helper 1 response predom-inance with a dysregulation of regulatory T cell (Treg) expression in DLE lesions that induced high levels of proinflammatory, chemotaxis, and apoptotic proteins that induce the chronic inflammation response. Thalidomide's anti-inflammatory, antiangiogenic, and T-cell co-stimulatory effects may be beneficial for DLE since it promotes cytokine inhibition, inhibits macrophage activation, regulates Treg responses, inhibits angiogenesis, modulates T cells, and promotes NK cell-mediated cytotoxicity.

Thalidomide (THD) alleviates radiation induced lung fibrosis (RILF) via down-regulation of TGF-β/Smad3 signaling pathway in an Nrf2-dependent manner

Radiation-induced lung fibrosis (RILF) is a complication of radiotherapy in thoracic cancer patients. Thalidomide (THD) has a therapeutic effect on fibrotic and inflammatory disorders. The purpose of the current study was to investigate the therapeutic effect of THD on RILF in mice and better understand the underlying regulatory mechanisms of the therapeutic effect. We found that THD mitigated the fibrosis caused by irradiation in mice. The action of THD on RILF was related to the elevation of low levels reactive oxygen species (ROS), which inhibited the transforming growth factor‑β (TGF‑β)/Smad3 signaling pathway through activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Analysis of the therapeutic effect of THD using Nrf2-/- mouse model confirmed the role of Nrf2 in vivo. In addition, no radioprotective effect of THD on thoracic cancer cell lines was observed. In conclusion, these data showed that THD attenuated RILF in mice, which was mediated by Nrf2-dependent down-regulation of the TGF-β/Smad3 pathway, suggesting THD as a potential novel agent for RILF prevention.

Neuro-ophthalmologic Manifestations of Sarcoidosis

The first-line treatment for the neuro-ophthalmologic manifestations of sarcoidosis is corticosteroid therapy. Prednisone, 0.5 to 1 mg/kg/day, is initially prescribed for 2 to 4 weeks, before a slow taper is begun as the patient's symptoms and examination are monitored. Patients frequently require adjunct therapy, which can be in the form of immunomodulatory drugs such as pentoxyfillin, hydroxychloroquine, or thalidomide, or immunosuppressive drugs such as mycophenolate mofetil, azathioprine, methotrexate, and cyclophosphamide. Individuals with profound visual compromise or progressive disease may benefit from high-dose intravenous methylprednisolone or tumor necrosis factor-alpha antagonists such as infliximab. Attention to the overall medical status of the patient is essential to ensure that an optimal clinical status is achieved.

Metabolism of thalidomide by human liver microsome cytochrome CYP2C19 is required for its antimyeloma and antiangiogenic activities in vitro

In this study, we used a system of human liver microsomes to investigate the antimyeloma and antiangiogenic activities of thalidomide. Myeloma cells and human umbilical vein endothelial cells (HUVECs) were treated with thalidomide alone or thalidomide incubated with human liver microsomal protein. We found that thalidomide alone had no direct effect on several multiple myeloma cell lines (U266, NCI-H929, RPMI 8226, LP-1, CZ-1) or on HUVECs in vitro. However, when incubated with human liver microsomal protein, thalidomide (100 µg/ml) caused a decrease of 34.9-46.7% in cell viability in myeloma cells and 12% in HUVECs. Cell cycle analysis and apoptosis detection indicated that the decreases in cell viability were correlated with the induction of apoptosis. Thalidomide incubated with microsomal protein also influenced HUVEC migration and tube formation. These effects were partially reversed by omeprazole (10 µmol/l), a potent inhibitor of CYP2C19, suggesting that CYP2C19 is required for thalidomide to exhibit its antimyeloma and antiangiogenic activities.

Efficacy of thalidomide in a girl with inflammatory calcinosis, a severe complication of juvenile dermatomyositis

We report a 14-year-old girl with juvenile dermatomyositis (JDM) complicated by severe inflammatory calcinosis successfully treated with thalidomide. She was diagnosed as JDM when she was 4 years old after a few months of increasing lethargy, muscle pain, muscle weakness, and rash. During three months, clinical manifestations and abnormal laboratory findings were effectively treated with oral prednisolone. However, calcinosis was recognized 18 months after disease onset. Generalized calcinosis rapidly progressed with high fever, multiple skin/subcutaneous inflammatory lesions, and increased level of CRP. Fifty mg/day (1.3 mg/kg day) of oral thalidomide was given for the first four weeks, and then the dose was increased to 75 mg/day. Clinical manifestations subsided, and inflammatory markers had clearly improved. Frequent high fever and local severe pain with calcinosis were suppressed. The levels of FDP-E, IgG, and tryglyceride, which were all elevated before the thalidomide treatment, were gradually returned to the normal range. Over the 18 months of observation up to the present, she has had no inflammatory calcinosis, or needed any hospitalization, although established calcium deposits still remain. Her condition became painless, less extensive and less inflammatory with the CRP level below 3.08 mg/dL. Recent examination by whole-body 18F-FDG-PET-CT over the 15 months of thalidomide treatment demonstrated fewer hot spots around the subcutaneous calcified lesions.

Targeted therapy in melanoma

Malignant melanoma is a highly lethal disease unless detected early. Single-agent chemotherapy is well tolerated but is associated with very low response rates. Combination chemotherapy and biochemotherapy may improve objective response rates but do not prolong survival and are associated with greater toxicity. Immunotherapeutic approaches such as highdose interleukin-2 are associated with durable responses in a small percentage of patients, but are impractical for many patients due to accessibility and toxicity issues. Elucidations of the molecular mechanisms of carcinogenesis in melanoma have expanded the horizon of opportunity to alter the natural history of the disease. Multiple signal transduction pathways seem to be aberrant and drugs that target them have been and continue to be in development. In this review we present data on the most promising targeted agents in development, including B-raf inhibitors and other signal transduction inhibitors, oligonucleotides, proteasome inhibitors, as well as inhibitors of angiogenesis. Most agents are in early phase trials although some have already reached phase III evaluation. As knowledge and experience with targeted therapy advance, new challenges appear to be arising particularly in terms of resistance and appropriate patient selection.

Thalidomide suppresses sclerosing encapsulating peritonitis in a rat experimental model

Peritoneal dialysis is an alternative treatment of patients with end-stage renal disease. Sclerosing encapsulating peritonitis is a life-threatening complication of continuous ambulatory peritoneal dialysis. The aim of the present study was to evaluate the effect of thalidomide, which is used for the treatment of various inflammatory and autoimmune diseases, on the development of sclerosing encapsulating peritonitis induced by chlorhexidine gluconate (CG). A peritoneal fibrosis model was established using rats treated intraperitoneally with injections of CG. Thalidomide was administered orally at a dose of 100 mg/kg three times per week. When compared with CG-treated rats, thalidomide (100 mg/kg orally)-treated mice subjected to CG-induced peritoneal fibrosis experienced a significantly lower rate in the extent and severity of histological signs of peritoneal injury. Thalidomide also caused a substantial reduction of 1) the rise in myeloperoxidase activity (mucosa); 2) the expression in the tissue of TNF-alpha, IL-1beta, transforming growth factor-beta, and vascular endothelial growth factor; 3) the increase in staining (immunohistochemistry) for nitrotyrosine and for poly(ADP ribose), as well as 4) the nuclear factor-kappaB activation caused by CG in the peritoneum. Thus, thalidomide treatment reduces the degree of peritoneal fibrosis caused by CG. We propose that this evidence may help clarify the potential therapeutic actions of thalidomide in patients with peritoneal fibrosis.

A phase II study of thalidomide in patients with brain metastases from malignant melanoma

INTRODUCTION

Brain metastases develop in nearly half of the patients with advanced melanoma and in 15 to 20% of these patients CNS is the first site of relapse. Overall median survival is short, ranging from 2 to 4 months. Thalidomide has antiangiogenic and immunomodulatory effects. Results obtained in prior trials indicate that Thalidomide acts as a cytostatic agent in metastatic melanoma. We evaluated single agent antitumour activity and toxicity of Thalidomide in a phase II setting in patients with brain metastases associated with metastatic melanoma.

MATERIAL AND METHODS

Patients with measurable metastatic melanoma in progression and with PS < or = 2 were enrolled in the study. Thalidomide was given orally. Dose was escalated over 4 weeks from 100 mg/day to 400 mg/day. Primary objective of the study was to determine response rate, according to RECIST. Secondary objectives were to estimate time to progression, overall survival and to evaluate tolerability of the regimen.

RESULTS

Twenty five men and 11 women were enrolled in the study, median age 48 years. Among 36 eligible patients 35 were evaluable for response. None of the patients obtained a response in brain metastases. Three patients obtained a partial response in extracranial lesions. Toxicity was acceptable and manageably. Median time to progression and overall survival time was 1.7 and 3.1 months, respectively.

CONCLUSION

There were no objective responses in the brain but single agent Thalidomide has some activity in melanoma patients with brain metastases. It has encouraged us to investigate Thalidomide in combination with Temozolomide, a very lipophilic agent, in this group of patients.

Effect of thalidomide on signal transduction pathways and secondary damage in experimental spinal cord trauma

TNF-alpha seems to play a central role in the inflammatory process of spinal cord injury. We tested the neuroprotective effects of thalidomide, an immunomodulatory agent that inhibits TNF-alpha production, which have not been investigated so far. The aim of our study was to evaluate the therapeutic efficacy of thalidomide in an experimental model of spinal cord trauma, which was induced by the application of vascular clips (force of 24 g) to the dura via a 4-level T5 to T8 laminectomy. Spinal cord injury in mice resulted in severe trauma characterized by edema, neutrophil infiltration, and cytokine production that is followed by recruitment of other inflammatory cells, production of a range of inflammation mediators, tissue damage, apoptosis, and disease. Thalidomide treatment significantly reduced the degree of: 1) spinal cord inflammation and tissue injury (histological score); 2) neutrophil infiltration (myeloperoxidase evaluation); 3) iNOS, nitrotyrosine, lipid peroxidation, and cytokine expression (TNF-alpha and IL-1beta); 4) apoptosis (terminal deoxynucleotidyltransferase-mediated UTP end labeling staining, and Bax and Bcl-2 expression); and 5) nuclear factor-kappaB activation. In a separate set of experiments, we have also clearly demonstrated that thalidomide significantly ameliorated the recovery of limb function (evaluated by motor recovery score). Taken together, our results clearly demonstrate that treatment with thalidomide reduces the development of inflammation and tissue injury events associated with spinal cord trauma.

A phase II study of thalidomide and temozolomide in patients with brain metastases from malignant melanoma: lymphopenia correlates with response

Background:

Central nervous system (CNS) metastases develop in nearly half of patients with advanced melanoma and in 15–20% CNS is the first site of relapse. Median overall survival is short, ranging from two to four months, and one-year survival rate is only 10–15%. THA has been shown to have both anti-angiogenetic and immuno-modulating effects. TMZ is an oral alkylating agent with an excellent oral bioavailability and it is highly lipophillic with an ability to penetrate the blood–brain barrier. TMZ and THA in combination were tested in patients with brain metastases from malignant melanoma.

Methods:

Between June 2004 and February 2007 patients with measurable metastatic melanoma in progression and PS ≤ 1 received TMZ in a dose of 150 mg/m² qd for seven days, followed by seven days off therapy and THA in 200 mg qd, both orally administered. Concomitant treatment with steroids was allowed. PBMCs were collected from the last 14 consecutive patients for evaluation of immune parameters.

Results:

Forty screened patients were eligible and evaluable for response, and 39 were evaluable for toxicity. 25 patients had asymptomatic and 15 symptomatic brain metastases. The toxicity was primarily grade 1–2 with no grade 4 or treatment-related deaths. Four patients had thromboembolic events grade 3. One patient obtained a CR and five a PR in the CNS, while two had CR and four had PR outside CNS. Overall response rate was 17.5%. We found a significant positive correlation between lymphopenia and objective response.

Conclusions:

The combination treatment was well tolerated but with more frequent thromboembolic events compared to single drug TMZ or THA. The treatment demonstrated activity in CNS as well as outside CNS. The correlation between lymphopenia and objective response needs further investigation.

Small molecule intercalation with double stranded DNA: implications for normal gene regulation and for predicting the biological efficacy and genotoxicity of drugs and other chemicals

The binding of small molecules to double stranded DNA including intercalation between base pairs has been a topic of research for over 40 years. For the most part, however, intercalation has been of marginal interest given the prevailing notion that binding of small molecules to protein receptors is largely responsible for governing biological function. This picture is now changing with the discovery of nuclear enzymes, e.g. topoisomerases that modulate intercalation of various compounds including certain antitumor drugs and genotoxins. While intercalators are classically flat, aromatic structures that can easily insert between base pairs, our laboratories reported in 1977 that a number of biologically active compounds with greater molecular thickness, e.g. steroid hormones, could fit stereospecifically between base pairs. The hypothesis was advanced that intercalation was a salient feature of the action of gene regulatory molecules. Two parallel lines of research were pursued: (1) development of technology to employ intercalation in the design of safe and effective chemicals, e.g. pharmaceuticals, nutraceuticals, agricultural chemicals; (2) exploration of intercalation in the mode of action of nuclear receptor proteins. Computer modeling demonstrated that degree of fit of certain small molecules into DNA intercalation sites correlated with degree of biological activity but not with strength of receptor binding. These findings led to computational tools including pharmacophores and search engines to design new drug candidates by predicting desirable and undesirable activities. The specific sequences in DNA into which ligands best intercalated were later found in the consensus sequences of genes activated by nuclear receptors implying intercalation was central to their mode of action. Recently, the orientation of ligands bound to nuclear receptors was found to match closely the spatial locations of ligands derived from intercalation into unwound gene sequences suggesting that nuclear receptors may be guiding ligands to DNA with remarkable precision. Based upon multiple lines of experimental evidence, we suggest that intercalation in double stranded DNA is a ubiquitous, natural process and a salient feature of the regulation of genes. If double stranded DNA is proven to be the ultimate target of genomic drug action, intercalation will emerge as a cornerstone of the future discovery of safe and effective pharmaceuticals.

Reversal effect of thalidomide on established hepatic cirrhosis in rats via inhibition of nuclear factor-kappaB/inhibitor of nuclear factor-kappaB pathway

BACKGROUND

Suppression of nuclear factor-kappaB (NF-kappaB)/inhibitor of nuclear factor-kappaB (IkappaB) signaling pathway is a potential property of thalidomide. This study was designed to investigate the effects of thalidomide on expressions of NF-kappaB, IkappaB and intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule (VCAM-1) in established rat liver cirrhosis.

METHODS

Rat liver cirrhosis was achieved by IP injection of carbon tetrachloride (CCl4) three times weekly for 8 weeks. CCl4 was then discontinued and thalidomide (100 mg/kg) or its vehicle was administered daily by gavage for 6 weeks. Hydroxyproline (HYP) content in liver was detected by biochemical assay. NF-kappaBp65, ICAM-1, VCAM-1 and alpha-smooth muscle actin (alpha-SMA) protein in the liver, IkappaBalpha protein in cytoplasm and NF-kappaBp65 protein in nucleus and ICAM-1, VCAM-1 mRNA levels in the liver were studied using immunohistochemistry, Western blot, and reverse transcriptase polymerase chain reaction, respectively.

RESULTS

Compared with the spontaneous recovery of cirrhosis, the histopathology of liver of rats given thalidomide was significantly improved. HYP content in liver, the expressions of ICAM-1, VCAM-1 mRNA and protein, NF-kappaBp65 and alpha-SMA protein were decreased significantly and IkappaBalpha protein in liver was elevated significantly in this group.

CONCLUSIONS

Thalidomide may exert its effect on downregulation of NF-kappaB-induced adhesion molecules and activation of hepatic stellate cell via inhibition of degradation of IkappaB to reverse established rat hepatic cirrhosis.

Cutaneous sarcoidosis therapy updated

The widely accepted standard therapy for cutaneous sarcoidosis includes corticosteroids, antimalarials, and methotrexate. However, a better understanding of the basic immunopathogenic properties of sarcoidosis has elucidated a number of steps critical to the persistence and progression of disease that may be vulnerable to treatment by targeted therapy. This article reviews both standard and newer therapeutic options for cutaneous sarcoidosis.

Thalidomide prevents rat liver cirrhosis via inhibition of oxidative stress

This study investigated the effect of thalidomide on oxidative stress in rat liver cirrhosis. The cirrhosis of rat was induced by intraperitoneal injection of carbon tetrachloride thrice weekly; meanwhile, thalidomide (10mg/kg or 100mg/kg) was given daily by intragastric administration for 8 weeks. The content of oxidative stress parameters, including superoxide dismutase, glutathione peroxidase, and malondialdehyde, in the liver was detected by biochemical assay. Immunohistochemistry revealed alpha-smooth muscle actin (alpha-SMA), desmin, and tissue inhibitor of metalloproteinase-1 (TIMP-1) protein in the liver. Nuclear factor kappa B p65 (NF-kappaBp65) protein in nucleus and transforming growth factor beta1 (TGF-beta1) protein in cytoplasm were detected by Western blot. NF-kappaBp65, TGF-beta1, and TIMP-1 mRNA levels in the liver were studied using reverse transcriptase polymerase chain reaction. Liver histopathology was significantly improved in rats given high doses of thalidomide. The content of oxidative stress parameters and the expressions of NF-kappaBp65, TGF-beta1 and TIMP-1 protein, and mRNA were significantly decreased in these animals. The expressions of alpha-SMA and Desmin protein were also significantly decreased in them. Thalidomide might exert an effect on the inhibition of oxidative stress via downregulation of NF-kappaB signaling pathway to prevent the progression of liver cirrhosis.

Thalidomide in Rat Liver Cirrhosis: Blockade of Tumor Necrosis Factor-α via Inhibition of Degradation of an Inhibitor of Nuclear Factor-κB

BACKGROUND/AIMS

Thalidomide inhibited tumor necrosis factor-alpha (TNF-alpha) effectively in many trials. The aim of this study was to investigate the effect of thalidomide on the expression of nuclear factor-kappaB (NF-kappaB), inhibitor of NF-kappaB (IkappaB) and TNF-alpha in a rat model of liver cirrhosis.

METHODS

Liver cirrhosis was achieved by intraperitoneal injection of carbon tetrachloride thrice weekly, and thalidomide (10 or 100 mg/kg/day) was given daily by intragastric route for 8 weeks. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), prealbumin (PA), hyaluronic acid (HA) and laminin (LN), and hydroxyproline (HYP), NF-kappaBp65, alpha-smooth muscle actin (alpha-SMA) protein and TNF-alpha mRNA were studied in the liver, IkappaBalpha and TNF-alpha protein in the cytoplasm and NF-kappaBp65 protein in the nucleus.

RESULTS

Compared with nontreated cirrhotic rats, the histopathology of rats given thalidomide (100 mg/kg) was significantly better. Serum ALT, AST, HA and LN and HYP content in the liver were significantly decreased and PA was elevated (p < 0.01) in this group; the expression of TNF-alpha mRNA and protein, NF-kappaBp65 and alpha-SMA were significantly decreased and IkappaBalpha protein was also elevated (p < 0.01).

CONCLUSION

Thalidomide downregulates NF-kappaB-induced TNF-alpha and activates hepatic stellate cells (HSC) via inhibition of IkappaB degradation to prevent liver cirrhosis.

Treatment of chronic hepatitis C in non-responsive patients with pegylated interferon associated with ribavirin and thalidomide: report of six cases of total remission

Hepatitis C virus (HCV) infection is an important public health issue worldwide. It is estimated that over 170 million people are infected with the virus. The present study reports six cases in which patients did not respond to combination therapy with pegylated interferon and ribavirin. However, after the addition of thalidomide to the therapy, the patients presented negative RNA PCR. The use of thalidomide combined with pegylated interferon and ribavirin for the treatment of hepatitis C is described here for the first time in the related literature.

Effects of thalidomide on the expression of adhesion molecules in rat liver cirrhosis

This study was to evaluate the effects of thalidomide on expression of adhesion molecules in liver cirrhosis. The cirrhosis was induced in Wistar rats by intraperitoneal injection of CCl(4), and thalidomide (10 mg/kg/day or 100 mg/kg/day) was given by intragastric administration for 8 weeks. Liver histopathology and immunohistochemistry were significantly improved and the expressions of ICAM-1, VCAM-1, E-selectin, and TNF-alpha mRNA and protein were decreased significantly in rats treated with a high dose of thalidomide. Close positive correlation was observed in the expression of the TNF-alpha mRNA and that of ICAM-1, VCAM-1, and E-selectin mRNA, respectively. These results indicate that thalidomide exerts its effect on the downregulation of adhesion molecules via TNF-alpha signaling pathway to inhibit liver fibrosis.

Thalidomide does not interact with P-glycoprotein

BACKGROUND

There is growing clinical interest in thalidomide for the treatment of various disorders due to its anti-inflammatory, immunomodulatory, and anti-angiogenic properties. In numerous clinical trials thalidomide is used as an adjunct to standard therapy. Therefore, clinicians should be aware of all possible drug-drug interactions that might occur with this drug. P-glycoprotein (P-gp), a drug efflux transporter that is expressed in many tissues, is the cause of several drug-drug interactions. P-gp induction or inhibition can lead to ineffective therapy or side-effects. In this study, we investigated thalidomide's potential to cause drug-drug interactions on the level of P-gp.

METHODS

LS180 cells were incubated with thalidomide for 72 h in order to determine P-gp induction using real-time RT-PCR. A human leukaemia cell line over-expressing MDR1 (CCRF-CEM/MDR1) was used to measure uptake of rhodamine 123, a P-gp substrate, in the presence of thalidomide. Dose-dependent and bi-directional transport of thalidomide through Caco-2 cell monolayers was performed to assess site-directed permeability. Transport rates were determined using HPLC including chiral separation of the thalidomide enantiomers.

RESULTS

Thalidomide did not induce P-gp expression in LS180 cells. The uptake of rhodamine 123 in CCRF cells over-expressing MDR1 was not influenced by co-incubation with thalidomide. The transport through Caco-2 monolayers was linear and the permeability was similar for both directions. No differences between the thalidomide enantiomers were observed.

CONCLUSIONS

Our study indicates that thalidomide is neither a substrate, nor an inhibitor or an inducer of P-gp. Therefore, P-gp-related drug-drug interactions with thalidomide are not likely.

Effects of thalidomide on angiogenesis and tumor growth and metastasis of human hepatocellular carcinoma in nude mice

AIM: To investigate the effects of thalidomide on angiogenesis, tumor growth and metastasis of hepatocellular carcinoma in nude mice.

METHODS: Twenty-four nude mice were randomly divided into therapy group and control group, 12 mice in each group. Thalidomide dissolved in 0.5% sodium carboxyl methyl cellulose (CMC) suspension was administered intraperitoneally once a day at the dose of 200 mg/kg in therapy group, and an equivalent volume of 0.5% CMC in control group. Mice were sacrificed on the 30^th d, tumor size and weight and metastases in liver and lungs were measured. CD34 and VEGF mRNA in tumor tissue were detected by immunohistochemistry and semi-quantitative RT-PCR respectively and microvessel density (MVD) was counted. Serum concentrations of TNF-α and ALT and AFP were also tested.

RESULTS: MVD and VEGF mRNA in therapy group were less than those in control group (31.08±16.23 vessels/HP vs 80.00±26.27 vessels/HP, 0.0538±0.0165 vs 0.7373±0.1297, respectively, P<0.05). No statistical difference was observed in tumor size and weight and metastases in liver and lungs. TNF-α was significantly lower in therapy group than in control group (28.64±4.64 ng/L vs 42.69±6.99 ng/L, P<0.05). No statistical difference in ALT and AFP was observed between groups.

CONCLUSION: Thalidomide can significantly inhibit angiogenesis and metastasis of hepatocellular carcinoma. It also has inhibitory effects on circulating TNF-α.

Inhibiting cytokines of the interleukin-12 family: recent advances and novel challenges

Interleukin-12 (IL-12) and the more recently discovered IL-23 and IL-27 constitute a unique family of structurally related, heterodimeric cytokines that regulate cell-mediated immune responses and T helper 1 (Th1)-type inflammatory reactions. Not surprisingly, the potentiality of treating conditions such as multiple sclerosis (MS) and rheumatoid arthritis (RA) through pharmacological interference with IL-12 pathways has received widespread attention. In this review we have examined over 50 substances with reported IL-12 inhibitory effects. We demonstrate that a majority of these belong to a limited number of major functional classes, each of which targets discrete events in the IL-12 biological pathway. Thus, most IL-12 inhibitory substances appear to work either through inhibition of transcription factor NF-kappa B activation, up-regulation of intracellular cAMP, blockage of posttranslational processing or interference with signal transduction pathways. In addition, cyclophilin-binding drugs, and generic inhibitors of nuclear histone deacetylases, and of ion channels, pumps and antiporters are emerging as potential leads to novel targets for interference with IL-12 production. Many inhibitors of NF-kappa B and of IL-12 signal transduction have been proven effective in limiting or preventing disease in experimental autoimmune encephalomyelitis (EAE) models of MS. The sharing of the p40 subunit, the IL-12R beta 1 and components of the signal transduction pathways between IL-12 and IL-23 raises the question as to whether the beneficial effects of various drugs previously ascribed to inhibition of IL-12 may, in fact, have been due to concurrent blockage of both cytokines, or of IL-23, rather than IL-12. Moreover, the homodimeric beta(2)-form of IL-12, though originally considered to display only antagonistic effects, is now emerging as a pronounced agonist in a variety of inflammatory processes. Reassessment of IL-12 inhibitory compounds is therefore needed to scrutinize their effects on IL-12 alpha beta, beta(2) and IL-23 formation. This is likely to open exciting perspectives to the identification of drugs that target these cytokines either indiscriminately or selectively. The functional diversity of presently available inhibitors should facilitate an unprecedented flexibility in designing future trials for the treatment of IL-12- and IL-23-mediated disorders.

Neurological complications of sarcoidosis

PURPOSE OF REVIEW

The neurological manifestations of sarcoidosis, which occur in 5% of patients with the condition, present in a variety of ways that can be assigned to several broad categories. A comprehensive approach to the diagnosis and management of neurosarcoidosis involves an appreciation of the strategies to confirm a diagnosis of sarcoidosis and neurosarcoidosis and the available therapeutic options.

RECENT FINDINGS

In addition to traditional approaches to the diagnosis of sarcoidosis, positron emission tomography can be used to identify otherwise occult sites of systemic inflammation which can be targeted for biopsy. Although corticosteroids remain the mainstay of treatment, other immunosuppressive and immunomodulatory agents can be used in the multi-modality therapy of sarcoidosis.

SUMMARY

Neurosarcoidosis can be 'staged' with the use of neurodiagnostic testing and diagnosed with varying degrees of certainty. Treatment should be approached within the context of the anticipated clinical course of the patient, avoidance of adverse drug effects, and, as necessary, from the perspective of the comprehensive management of a chronic disease.

Thalidomide

Despite its history as a human teratogen, thalidomide is emerging as a treatment for cancer and inflammatory diseases. Although the evolution of its clinical application could not have been predicted from the tragedy associated with its misuse in the past, its history serves as a lesson in drug development that underscores the need to understand the molecular pharmacology of a compound's activity, including associated toxicities. Here, we summarise the applications for thalidomide with an emphasis on clinical trials published over the past 10 years, and consider our knowledge of the molecular pharmacology of the drug in the context of clinical trial data, attempting to provide a mechanism-guided understanding of its activity.

Anti-angiogenic effect of silymarin on colon cancer LoVo cell line

OBJECTIVE

This study was designed to evaluate the anti-angiogenic effect of silymarin (SM) and its major pure component silibinin (SB), and also thalidomide (TH).

MATERIALS AND METHODS

A modified in vitro system using a coculture of endothelial (EA.hy 926) and colon cancer (LoVo) cell lines was adopted in this study.

RESULTS

In cytotoxicity assay, SM/SB/TH concentrations causing 20% (IC(20)) inhibition of cellular growth were 41.8 microg/ml/0.22 mM/0.088 mM for EA.hy 926 cells, and 16.1 microg/ml/0.12 mM/0.099 mM for LoVo cells, respectively. All 3 drugs showed concentration dependent inhibition of migration and differentiation assay. The IC(50) inhibiting chemotaxis migration of EA.hy 926 towards LoVo by SM/SB/TH was 1.15 microg/ml/0.66 microM/1.98 microM, respectively. In differentiation assay, SM/SB/TH inhibited in vitro capillary tube formation by 50% at 1.25 microg/ml/2.6 micro/6.3 microM, respectively. In an analysis of vascular endothelial growth factor secreted by LoVo cells, SM/SB/TH decreased 50% secretion at 6.52 microg/ml/6.6 microM/131.7 microM, respectively.

CONCLUSION

SM/SB has a strong anti-angiogenesis effect on the colon cancer cell line, and this might provide an alternative treatment option for anti-cancer treatment.

Advances in molecular therapies in patients with brain tumors

BACKGROUND

We are witnessing the development of new treatment modalities for primary brain tumors. An area under intense investigation is the use of small molecules targeting intracellular signaling pathways that interfere with growth, invasion, and metastasis of high-grade gliomas.

METHODS

We review clinical trials of small molecules in adults with brain tumors. This search included electronic databases, specialty journals, textbooks, proceedings, and Web sites of the National Cancer Institute and other cooperative brain tumor groups in Europe and the United States.

RESULTS

Several drugs with the ability to down-regulate the growth and invasion of malignant gliomas are at various stages of testing. Most of these focus on interfering with oncogenic and tumor survival pathways. Examples include inhibitors of tyrosine kinases, farnesyltransferases, and matrix metalloproteinases. These molecules are at different stages of testing, and a conclusive picture of which drug is most effective, either alone or in combination, needs better definition. The metalloproteinase inhibitor marimastat with temozolomide has given the best results to date in phase II trials, increasing the rate of 6-month progression-free survival for recurrent glioblastoma multiforme and anaplastic gliomas.

CONCLUSIONS

As our understanding of the biology of gliomas increases and new drugs targeting specific molecular pathways enter well-designed cooperative trials, the control and prognosis of these tumors should improve.

A case of refractory Henoch-Schönlein purpura treated with thalidomide

Henoch-Schönlein purpura is an acute, self-limited vasculitis syndrome which shows characteristic skin, joint, renal and gastrointestinal manifestations. It is common in childhood and may also occur in adults with fatal complications such as nephritis and gastrointestinal bleeding. We experienced a case of a 20-year-old woman who presented with palpable purpura and severe arthritis. The histopathologic examination of the skin revealed leukocytoclastic vasculitis with perivascular deposition of IgA and she was diagnosed with Henoch-Schönlein purpura. Despite treatment with prednisolone for one month, she had more aggravated purpura and fatal gastrointestinal bleeding. The symptoms were improved shortly by cyclophosphamide pulse therapy with plasmapheresis but symptoms were aggravated and symmetric mononeuropathy of the ulnar nerve developed. She was treated with 400 mg/day of thalidomide and symptoms were improved. We herein report a case of Henoch-Schönlein purpura successfully treated with thalidomide which was refractory to prednisolone, immunosuppressive drugs and plasmapheresis.

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.

New developments in the treatment of inflammatory bowel disease

Therapy of inflammatory bowel disease (IBD) is rapidly changing with the advent of new discoveries in disease pathogenesis. The need for targeted therapies against the uncontrolled immuno-inflammatory reaction in IBD together with a prerequisite for minimal side effects is driving improvement in old medicines and is leading to the development of new drugs. This review introduces emerging changes in IBD treatment, such as improvements in conventional IBD medications or their use. Balsalazide, budesonide and changes in the use of 5-aminosalicylate (5-ASA) products and purine analogues, such as azathioprine, are discussed. Additionally, studies examining the role of drugs newly introduced into IBD therapy, such as mycophenolate mofetil (MMF), thalidomide and heparin, are stated. Emerging biological therapies, such as therapies against TNF, therapies to enhance anti-inflammatory cytokines, therapeutic manoeuvres to disrupt immune cell trafficking, anti-oxidant therapies, as well as non-conventional treatments, such as diet therapies, prebiotics and probiotics, and helminth therapies are discussed.