The influence of thalidomide on the clinical and immunologic manifestation of erythema nodosum leprosum

Reshaping the tumor microenvironment: The versatility of immunomodulatory drugs in B-cell neoplasms

Immunomodulatory drugs (IMiDs) such as thalidomide, lenalidomide and pomalidomide are antitumor compounds that have direct tumoricidal activity and indirect effects mediated by multiple types of immune cells in the tumor microenvironment (TME). IMiDs have shown remarkable therapeutic efficacy in a set of B-cell neoplasms including multiple myeloma, B-cell lymphomas and chronic lymphocytic leukemia. More recently, the advent of immunotherapy has revolutionized the treatment of these B-cell neoplasms. However, the success of immunotherapy is restrained by immunosuppressive signals and dysfunctional immune cells in the TME. Due to the pleiotropic immunobiological properties, IMiDs have shown to generate synergetic effects in preclinical models when combined with monoclonal antibodies, immune checkpoint inhibitors or CAR-T cell therapy, some of which were successfully translated to the clinic and lead to improved responses for both first-line and relapsed/refractory settings. Mechanistically, despite cereblon (CRBN), an E3 ubiquitin ligase, is considered as considered as the major molecular target responsible for the antineoplastic activities of IMiDs, the exact mechanisms of action for IMiDs-based TME re-education remain largely unknown. This review presents an overview of IMiDs in regulation of immune cell function and their utilization in potentiating efficacy of immunotherapies across multiple types of B-cell neoplasms.

Thalidomide modulates renal inflammation induced by brain death experimental model

BACKGROUND

Brain death (BD) is characterized by a complex inflammatory response, resulting in dysfunction of potentially transplantable organs. This process is modulated by cytokines, which amplify graft immunogenicity. We have investigated the inflammatory response in an animal model of BD and analyzed the effects of thalidomide, a drug with powerful immunomodulatory properties.

METHODS

BD was induced in male Lewis rats. We studied three groups: Control (sham-operated rats) (n = 6), BD (rats subjected to brain death) (n = 6) and BD + Thalid (BD rats treated with one dose of thalidomide (200 mg/Kg), administered by gavage) (n = 6). Six hours after BD, serum levels of urea and creatinine, as well as systemic and renal tissue protein levels of TNF-α and IL-6, were analyzed. We also determined the mRNA expression of ET-1, and macrophage infiltration by immunohistochemistry.

RESULTS

BD induced a striking inflammatory status, demonstrated by a significant increase of plasma cytokines: TNF-α (2.8 ± 4.3 pg/mL [BD] vs. 9.4 ± 2.8 pg/mL [Control]), and IL-6 (6219.5 ± 1380.6 pg/mL [BD] vs. 1854.7 ± 822.6 pg/mL [Control]), and in the renal tissue: TNF-α (2.5 ± 0.3 relative expression [BD] vs. 1.0 ± 0.4 relative expression [Control]; p < 0.05), and IL-6 (4.0 ± 0.4 relative expression [BD] vs. 1.0 ± 0.3 relative expression [Control]; p < 0.05). Moreover, BD increased macrophages infiltration (2.47 ± 0.07 cells/field [BD] vs. 1.20 ± 0.05 cells/field [Control]; p < 0.05), and ET-1 gene expression (2.5 ± 0.3 relative expression [BD] vs. 1.0 ± 0.2 relative expression [Control]; p < 0.05). In addition, we have observed deterioration in renal function, characterized by an increase of urea (194.7 ± 25.0 mg/dL [BD] vs. 108.0 ± 14.2 mg/dL [Control]; p < 0.05) and creatinine (1.4 ± 0.04 mg/dL [BD] vs. 1.0 ± 0.07 mg/dL [Control]; p < 0.05) levels. Thalidomide administration significantly reduced plasma cytokines: TNF-α (5.1 ± 1.4 pg/mL [BD + Thalid] vs. BD; p < 0.05), and IL-6 (1056.5 ± 488.3 pg/mL [BD + Thalid] vs. BD; p < 0.05), as well as in the renal tissue: TNF-α (1.5 ± 0.2 relative expression [BD + Thalid] vs. BD; p < 0.05), and IL-6 (2.1 ± 0.3 relative expression [BD + Thalid] vs. BD; p < 0.05). Thalidomide treatment also induced a significant decrease in the expression of ET-1 (1.4 ± 0.3 relative expression [BD + Thalid] vs. BD; p < 0.05), and macrophages infiltration (1.17 ± 0.06 cells/field [BD + Thalid] vs. BD; p < 0.05). Also thalidomide prevented kidney function failure by reduced urea (148.3 ± 4.4 mg/dL [BD + Thalid] vs. BD; p < 0.05), and creatinine (1.1 ± 0.14 mg/dL [BD + Thalid] vs. BD; p < 0.05).

CONCLUSIONS

The immunomodulatory properties of thalidomide were effective in decreasing systemic and local immunologic response, leading to diminished renal damage, as reflected in the decrease of urea and creatinine levels. These results suggest that use of thalidomide may represent a potential strategy for treating in BD kidney organ donors.

A real-world study of low-dose thalidomide in severe erythema nodosum leprosum highlighting its mechanistic rationale in a resource-constrained target population

BACKGROUND

Corticosteroids remain the main therapy in erythema nodosum leprosum (ENL), and long-term usage in chronic or recurrent ENL is a cause of significant morbidity and mortality. Thalidomide exerts dramatic effect in controlling ENL and helps reduce the dose of steroids, but the cost is a hindrance to its usage.

METHODS

Patients of ENL (steroid naïve and steroid-dependent) were recruited over a 1-year period. An escalating dose of low-dose thalidomide with a reducing dose of prednisolone was titrated depending on the control of disease activity. The primary aim was to reduce the dose of steroids to the lowest effective dose, and the secondary aim was to stop.

RESULTS

Sixteen patients of ENL were studied (mean duration of ENL 22.1 months, 15 severe ENL), and a majority (11/16, 68%) were on steroids with a mean duration of 11.27 months. All patients had steroid-related side effects (cushingoid habitus 81.8%, weight gain 54.5%, diabetes mellitus 9%, hyperlipidemia 18.18%, cataract 18.1%, osteoporosis 36.3%, striae 36.3%, acneiform eruptions 18.1%, and myopathy 9%). Steroids could be tapered in a majority of patients (n = 9) within 3 months (mean 2.44 months) with a low dose of thalidomide (25-150 mg/day, mean 78.3 mg) achieving a significant reduction in prednisolone dose (33.16 mg at baseline; 4.28 mg at 3 months, P < 0.05). Steroids could be stopped in 92% of patients by 3.03 months, and both drugs could be stopped in 80% of cases by 5.83 months.

CONCLUSION

The rapid and effective control of ENL with low-dose thalidomide in our series is comparable to the historical efficacy of high-dose thalidomide regimens, making it an affordable therapy in resource-constrained settings and an excellent steroid-sparing agent. The rapid onset of disease control is likely attributable to its action via neutrophils.

Host-Related Laboratory Parameters for Leprosy Reactions

Leprosy reactions are acute inflammatory episodes that complicate the course of a Mycobacterium leprae infection and are the major cause of leprosy-associated pathology. Two types of leprosy reactions with relatively distinct pathogenesis and clinical features can occur: type 1 reaction, also known as reversal reaction, and type 2 reaction, also known as erythema nodosum leprosum. These acute nerve-destructive immune exacerbations often cause irreversible disabilities and deformities, especially when diagnosis is delayed. However, there is no diagnostic test to detect or predict leprosy reactions before the onset of clinical symptoms. Identification of biomarkers for leprosy reactions, which impede the development of symptoms or correlate with early-onset, will allow precise diagnosis and timely interventions to greatly improve the patients' quality of life. Here, we review the progress of research aimed at identifying biomarkers for leprosy reactions, including its correlation with not only immunity but also genetics, transcripts, and metabolites, providing an understanding of the immune dysfunction and inflammation that underly the pathogenesis of leprosy reactions. Nevertheless, no biomarkers that can reliably predict the subsequent occurrence of leprosy reactions from non-reactional patients and distinguish type I reaction from type II have yet been found.

Immunomodulatory effects of thalidomide in an experimental brain death liver donor model

Brain death is characterized by a generalized inflammatory response that results in multiorgan damage. This process is mainly mediated through cytokines, which amplify graft immunogenicity. We investigated the immunological response in a brain death liver donor model and analysed the effects of thalidomide, a drug with powerful immunomodulatory properties. Brain death was induced in male Lewis rats. We studied three groups: Control (sham-operated rats in which trepanation was performed without inserting the balloon catheter), BD (rats subjected to brain death by increasing intracranial pressure) and BD + Thalid (BD rats receiving thalidomide after brain death). After 6 h, serum levels of AST, ALT, LDH, and ALP as well as systemic and hepatic levels of TNF-α, IL1-β, IL-6, and IL-10 were analysed. We also determined the mRNA expression of MHC Class I and Class II, NF-κB, and macrophage infiltration. NF-κB was also examined by electrophoretic mobility shift assay. Thalidomide treatment significantly reduced serum levels of hepatic enzymes and TNF-α, IL-1-β, and IL-6. These cytokines were evaluated at either the mRNA expression or protein level in liver tissue. In addition, thalidomide administration resulted in a significant reduction in macrophages, MHC Class I and Class II, and NF-κB activation. This study reveals that thalidomide significantly inhibited the immunologic response and graft immunogenicity, possibly through suppression of NF-κB activation.

Role of innate immunity in chemotherapy-induced peripheral neuropathy

It has become increasingly clear that the innate immune system plays an essential role in the generation of many types of neuropathic pain including that which accompanies cancer treatment. In this article we review current findings of the role of the innate immune system in contributing to cancer treatment pain at the distal endings of peripheral nerve, in the nerve trunk, in the dorsal root ganglion and in the spinal dorsal horn.

Increased serum levels of interleukin-6 in erythema nodosum leprosum suggest its use as a biomarker

BACKGROUND

Erythema nodosum leprosum (ENL) is a frequent complication of multibacillary leprosy that can result in significant morbidity, including peripheral nerve damage and physical disability. The identification of possible serum markers could be a valuable tool for the early detection of ENL.

AIMS

The purpose of this study was to evaluate selected serum mediators involved in the innate and adaptive immune responses to identify possible immunomarkers for ENL.

METHODS

The levels of interleukin-2, interleukin-4, interleukin-6, interleukin-10, interleukin-17, interferon-γ, tumor necrosis factor, nitric oxide and anti-phenolic glycolipid-I antibodies were measured in the sera of leprosy patients with ENL [at the beginning of reaction (M0) and 1 month later (M1)], and then compared with the levels of the same markers in patients with untreated multibacillary leprosy without ENL (controls with leprosy: CTRL) and healthy individuals (healthy controls: CTRH).

RESULTS

Significantly higher levels of serum interleukin-6 were observed in M0 than in CTRL. In addition, pairwise comparisons showed higher levels of interleukin-6 in M0 compared to M1. Levels of tumor necrosis factor were higher in M0 than in CTRL, with no significant difference between M0 and M1. There were no differences in the levels of interleukin-2, interleukin-4, interleukin-10, interleukin-17 or interferon-γ between groups. The CTRL group had higher levels of nitric oxide compared to M0 and M1. High levels of anti-phenolic glycolipid-I were observed in M0, M1 and CTRL than in CTRH.

LIMITATIONS

Three patients were not assessed at M1, decreasing the number of evaluated patients from 14 to 11.

CONCLUSION

High-serum levels of interleukin-6 were observed during ENL, primarily in patients with more severe reactions; levels decreased after specific therapy, suggesting a role for this cytokine in pathogenesis and its utility as an ENL biomarker. Further studies should explore whether interleukin-6 could also be used as a predictive marker for ENL or as a specific target for its treatment.

Mechanism of Action and Novel IMiD-Based Compounds and Combinations in Multiple Myeloma

Over the last 2 decades, thalidomide analogs have induced significant antimyeloma effects via immune-modulation, antiangiogenesis and antiproliferative effects. While the exact molecular mechanism of the targets or the mediators of thalidomide activity were not known, a seminal discovery of cereblon as a thalidomide-binding protein led to explaining the mechanistic basis of antimyeloma activity for this class of agents. Identification of the mechanisms of resistance for immunomodulatory agents (IMiDs), which will have significant clinical implications, remains poorly understood. Newer cereblon modulators with differential effects and improved increased efficacy in cell lines resistant to the current IMiDs are in development with encouraging preclinical data. In this review, we have summarized the mechanisms of action of IMiDs, clinical development, and potential mechanisms of resistance. We also describe novel IMiD-based combinations and the newer cereblon modulators as well.

Thalidomide and Phosphodiesterase 4 Inhibitors as Host Directed Therapeutics for Tuberculous Meningitis: Insights From the Rabbit Model

Tuberculous meningitis (TBM) is the most devastating form of extrapulmonary Mycobacterium tuberculosis infection in humans. Severe inflammation and extensive tissue damage drive the morbidity and mortality of this manifestation of tuberculosis (TB). Antibiotic treatment is ineffective at curing TBM due to variable and incomplete drug penetration across the blood-brain barrier (BBB) and blood-cerebrospinal fluid (CSF) barriers. Adjunctive corticosteroid therapy, used to dampen the inflammation, and the pathologic manifestation of TBM, improves overall survival but does not entirely prevent the morbidity of the disease and has significant toxicities, including immune-suppression. The rabbit has served as a fit for purpose experimental model of human TBM since the early 1900s due to the similarity in the developmental processes of the brain, including neuronal development, myelination, and microglial functions between humans and rabbits. Consistent with the observations made in humans, proinflammatory cytokines, including TNF-α, play a critical role in the pathogenesis of TBM in rabbits focusing the attention on the utility of TNF-α inhibitors in treating the disease. Thalidomide, an inhibitor of monocyte-derived TNF-α, was evaluated in the rabbit model of TBM and shown to improve survival and reduce inflammation of the brain and the meninges. Clinical studies in humans have also shown a beneficial response to thalidomide. However, the teratogenicity and T-cell activation function of the drug limit the use of thalidomide in the clinic. Thus, new drugs with more selective anti-inflammatory properties and a better safety profile are being developed. Some of these candidate drugs, such as phosphodiesterase-4 inhibitors, have been shown to reduce the morbidity and increase the survival of rabbits with TBM. Future studies are needed to assess the beneficial effects of these drugs for their potential to improve the current treatment strategy for TBM in humans.

Neutrophil extracellular traps contribute to the pathogenesis of leprosy type 2 reactions

Up to 50% of patients with the multibacillary form of leprosy are expected to develop acute systemic inflammatory episodes known as type 2 reactions (T2R), thus aggravating their clinical status. Thalidomide rapidly improves T2R symptoms. But, due to its restricted use worldwide, novel alternative therapies are urgently needed. The T2R triggering mechanisms and immune-inflammatory pathways involved in its pathology remain ill defined. In a recent report, we defined the recognition of nucleic acids by TLR9 as a major innate immunity pathway that is activated during T2R. DNA recognition has been described as a major inflammatory pathway in several autoimmune diseases, and neutrophil DNA extracellular traps (NETs) have been shown to be a prime source of endogenous DNA. Considering that neutrophil abundance is a marked characteristic of T2R lesions, the objective of this study was to investigate NETs production in T2R patients based on the hypothesis that the excessive NETs formation would play a major role in T2R pathogenesis. Abundant NETs were found in T2R skin lesions, and increased spontaneous NETs formation was observed in T2R peripheral neutrophils. Both the M. leprae whole-cell sonicate and the CpG-Hlp complex, mimicking a mycobacterial TLR9 ligand, were able to induce NETs production in vitro. Moreover, TLR9 expression was shown to be higher in T2R neutrophils, suggesting that DNA recognition via TLR9 may be one of the pathways triggering this process during T2R. Finally, treatment of T2R patients with thalidomide for 7 consecutive days resulted in a decrease in all of the evaluated in vivo and ex vivo NETosis parameters. Altogether, our findings shed light on the pathogenesis of T2R, which, it is hoped, will contribute to the emergence of novel alternative therapies and the identification of prognostic reactional markers in the near future.

Leprosy is caused by a mycobacterium that has a predilection for skin and nerve cells. The chronic course of the disease may be interrupted by acute inflammatory episodes known as reactions, despite effective bacterial killing with antibiotics. Reactions aggravate the patient’s clinical status and may become a medical emergency. Type 2 reactions (T2R) only occur in patients with high bacterial burden and are treated with thalidomide and/or corticosteroids. We are interested in understanding how inflammation is triggered and amplified during T2R. In this study we investigated the potential role of extracellular DNA released by neutrophils (known as NETs) in T2R, since they have been shown to cause inflammation. Abundant NETs were found in T2R skin lesions, and increased spontaneous NETs formation was observed in neutrophils present in the blood of T2R patients. Moreover, bacterial constituents were able to induce NETs production. Finally, treatment of T2R patients with thalidomide resulted in decreased NET formation. Altogether, our findings shed light on the pathogenesis of T2R, which, it is hoped, will contribute to the identification of biomarkers for early diagnosis and emergence of novel alternative therapies in the near future.

Elevated Pentraxin-3 Concentrations in Patients With Leprosy: Potential Biomarker of Erythema Nodosum Leprosum

Background

Leprosy, the leading infectious cause of disability worldwide, remains a major public health challenge in the most severely affected countries despite the sharp decline in new cases in recent years. The search for biomarkers is essential to achieve a better understanding of the molecular and cellular mechanisms underlying the disease.

Methods

Pentraxin-3 (PTX3) analyses of sera from 87 leprosy patients with or without reactions were conducted via enzyme-linked immunosorbent assay. In situ identification of PTX3 in skin lesion was confirmed by quantitative reverse-transcription polymerase chain reaction, immunohistochemistry, and immunofluorescence assays.

Results

We found that PTX3 serum levels were higher in multibacillary patients when evaluated before the onset of acute erythema nodosum leprosum (ENL) and persistently elevated during reaction. Thalidomide treatment reduced PTX3 in the serum 7 days after starting treatment. In situ analyses have also demonstrated enhancement of PTX3 in ENL lesions and showed that treatment with thalidomide reduced its expression and the prominent neutrophilic infiltrate, a hallmark of the disease.

Conclusions

In summary, our study provides in vivo evidence that PTX3 is enhanced during ENL but not in reversal reaction and provides a new molecular target in ENL pathogenesis.

Neutrophils in Leprosy

Leprosy is an infectious disease caused by the intracellular bacillus Mycobacterium leprae that mainly affects the skin and peripheral nerves. One of the most intriguing aspects of leprosy is the diversity of its clinical forms. Paucibacillary patients are characterized as having less than five skin lesions and rare bacilli while the lesions in multibacillary patients are disseminated with voluminous bacilli. The chronic course of leprosy is often interrupted by acute episodes of an inflammatory immunological response classified as either reversal reaction or erythema nodosum leprosum (ENL). Although ENL is considered a neutrophilic immune-complex mediated condition, little is known about the direct role of neutrophils in ENL and leprosy disease overall. Recent studies have shown a renewed interest in neutrophilic biology. One of the most interesting recent discoveries was that the neutrophilic population is not homogeneous. Neutrophilic polarization leads to divergent phenotypes (e.g., a pro- and antitumor profile) that are dynamic subpopulations with distinct phenotypical and functional abilities. Moreover, there is emerging evidence indicating that neutrophils expressing CD64 favor systemic inflammation during ENL. In the present review, neutrophilic involvement in leprosy is discussed with a particular focus on ENL and the potential of neutrophils as clinical biomarkers and therapeutic targets.

Synthesis and Biological Evaluation of Thalidomide Derivatives as Potential Anti-Psoriasis Agents

Several thalidomide derivatives were synthesized and evaluated for their anti-inflammatory activity. Introduction of the benzyl group to the parent thalidomide is unfavorable in which 2-(1-benzyl-2,6-dioxopiperidin-3-yl)isoindoline-1,3-dione (4a) was inactivated. However, the inhibitory activities on TNF-α and IL-6 expression in HaCaT cells were improved by the substitution of a chloro- or methoxy- group at the phenyl position of 4a. The IL-6 inhibitory activity decreased in an order of 5c (69.44%) > 4c (48.73%) > 6c (3.19%) indicating the 3-substituted derivative is more active than the 4-substituted counterpart, which in turn is more active than the 2-substituted counterpart. Among them, 2-[1-(3-chlorobenzyl)-2,6-dioxopiperidin-3-yl]isoindoline-1,3-dione (5c) was found to inhibit TNF-α and IL-6 expression in HaCaT cells with a higher potency than thalidomide and no significant cell cytotoxicity was detected at 10 μM. In psoriasis, Compound 5c reduced IL-6, IL-8, IL-1β and IL-24 in imiquimod-stimulated models. Our results indicated that compound 5c is a potential lead of novel anti-psoriasis agents. Structural optimization of compound 5c and its in vivo assay are ongoing.

Erythema Nodosum Leprosum: Update and challenges on the treatment of a neglected condition

Erythema Nodosum Leprosum (ENL) occurs due to the immunological complication of multibacillary leprosy and is characterized by painful nodules and systemic compromising. It is usually recurrent and/or chronic and has both physical and economic impact on the patient, being a very important cause of disability. In addition, ENL is a major health problem in countries where leprosy is endemic. Therefore, adequate control of this condition is important. The management of ENL aims to control acute inflammation and neuritis and prevent the onset of new episodes. However, all currently available treatment modalities have one or two drawbacks and are not effective for all patients. Corticosteroid is the anti-inflammatory of choice in ENL but may cause dependence, especially for chronic patients. Thalidomide has a rapid action but its use is limited due the teratogenicity and neurotoxicity. Clofazimine and pentoxifylline have slow action and have important adverse effects. Finally, there is no pattern or guidelines for treating these patients, becoming more difficult to evaluate and to control this condition. This review aims to show the main drugs used in the treatment of ENL and the challenges in the management of the reaction.

Correlates of immune exacerbations in leprosy

Leprosy is still a considerable health threat in pockets of several low and middle income countries worldwide where intense transmission is witnessed, and often results in irreversible disabilities and deformities due to delayed- or misdiagnosis. Early detection of leprosy represents a substantial hurdle in present-day leprosy health care. The dearth of timely diagnosis has, however, particularly severe consequences in the case of inflammatory episodes, designated leprosy reactions, which represent the major cause of leprosy-associated irreversible neuropathy. There is currently no accurate, routine diagnostic test to reliably detect leprosy reactions, or to predict which patients will develop these immunological exacerbations. Identification of host biomarkers for leprosy reactions, particularly if correlating with early onset prior to development of clinical symptoms, will allow timely interventions that contribute to decreased morbidity. Development of a point-of-care (POC) test based on such correlates would be a definite game changer in leprosy health care. In this review, proteomic-, transcriptomic and metabolomic research strategies aiming at identification of host biomarker-based correlates of leprosy reactions are discussed, next to external factors associated with occurrence of these episodes. The vast diversity in research strategies combined with the variability in patient- and control cohorts argues for harmonisation of biomarker discovery studies with geographically overarching study sites. This will improve identification of specific correlates associated with risk of these damaging inflammatory episodes in leprosy and subsequent application to rapid field tests.

Innate Immune Responses in Leprosy

Leprosy is an infectious disease that may present different clinical forms depending on host immune response to Mycobacterium leprae. Several studies have clarified the role of various T cell populations in leprosy; however, recent evidences suggest that local innate immune mechanisms are key determinants in driving the disease to its different clinical manifestations. Leprosy is an ideal model to study the immunoregulatory role of innate immune molecules and its interaction with nervous system, which can affect homeostasis and contribute to the development of inflammatory episodes during the course of the disease. Macrophages, dendritic cells, neutrophils, and keratinocytes are the major cell populations studied and the comprehension of the complex networking created by cytokine release, lipid and iron metabolism, as well as antimicrobial effector pathways might provide data that will help in the development of new strategies for leprosy management.

Thalidomide attenuates development of morphine dependence in mice by inhibiting PI3K/Akt and nitric oxide signaling pathways

Morphine dependence and the subsequent withdrawal syndrome restrict its clinical use in management of chronic pain. The precise mechanism for the development of dependence is still elusive. Thalidomide is a glutamic acid derivative, recently has been reconsidered for its clinical use due to elucidation of different clinical effects. Phosphoinositide 3-kinase (PI3K) is an intracellular transducer enzyme which activates Akt which in turns increases the level of nitric oxide. It is well established that elevated levels of nitric oxide has a pivotal role in the development of morphine dependence. In the present study, we aimed to explore the effect of thalidomide on the development of morphine dependence targeting PI3K/Akt (PKB) and nitric oxide (NO) pathways. Male NMRI mice and human glioblastoma T98G cell line were used to study the effect of thalidomide on morphine dependence. In both models the consequent effect of thalidomide on PI3K/Akt and/or NO signaling in morphine dependence was determined. Thalidomide alone or in combination with PI3K inhibitor, Akt inhibitor or nitric oxide synthase (NOS) inhibitors significantly reduced naloxone induced withdrawal signs in morphine dependent mice. Also, the levels of nitrite in hippocampus of morphine dependent mice were significantly reduced by thalidomide in compared to vehicle treated morphine dependent mice. In T98G human glioblastoma cells, thalidomide alone or in combination with PI3K and Akt inhibitors significantly reduced iNOS expression in comparison to the morphine treated cells. Also, morphine-induced p-Akt was suppressed when T98G cells were pretreated with thalidomide. Our results suggest that morphine induces Akt, which has a crucial role in the induction of NOS activity, leading to morphine dependence. Moreover, these data indicate that thalidomide attenuates the development of morphine dependence in vivo and in vitro by inhibition of PI3K/Akt and nitric oxide signaling pathways.

Using Genome Sequence to Enable the Design of Medicines and Chemical Probes

Rapid progress in genome sequencing technology has put us firmly into a postgenomic era. A key challenge in biomedical research is harnessing genome sequence to fulfill the promise of personalized medicine. This Review describes how genome sequencing has enabled the identification of disease-causing biomolecules and how these data have been converted into chemical probes of function, preclinical lead modalities, and ultimately U.S. Food and Drug Administration (FDA)-approved drugs. In particular, we focus on the use of oligonucleotide-based modalities to target disease-causing RNAs; small molecules that target DNA, RNA, or protein; the rational repurposing of known therapeutic modalities; and the advantages of pharmacogenetics. Lastly, we discuss the remaining challenges and opportunities in the direct utilization of genome sequence to enable design of medicines.

Thalidomide and its analogues: A review of the potential for immunomodulation of fibrosis diseases and opthalmopathy

The US Food and Drug Administration approved thalidomide and its analogues for the treatment of erythema nodosum leprosum, in spite of the notoriety of reports of severe birth defects in the middle of the last century. As immunomodulatory drugs, thalidomide and its analogues have been used to effectively treat various diseases. In the present review, preclinical data about the effects of thalidomide and its analogues on the immune system are integrated, including the effects of cytokines on transdifferentiation, the anti-inflammatory effect, immune cell function regulation and angiogenesis. The present review also investigates the latest developments of thalidomide as a therapeutic option for the treatment of idiopathic pulmonary fibrosis, skin fibrosis, and ophthalmopathies.

Thalidomide is Associated With Increased T Cell Activation and Inflammation in Antiretroviral-naive HIV-infected Individuals in a Randomised Clinical Trial of Efficacy and Safety

Trial Design

Open-label, randomised, controlled, pilot proof-of-concept clinical trial.

Methods

Participants: Antiretroviral naïve adult males with CD4 count ≥ 350 cells/mm³.

Interventions: Patients were randomised to receive thalidomide 200 mg QD for 3 weeks (Thalidomide group) or not (Control group) and followed for 48 weeks.

Objective: We hypothesized that short-term Thalidomide use would reduce HIV related inflammation and HIV replication among antiretroviral naïve HIV infected individuals.

Outcome: Viral loads, CD4/CD8 counts, ultra-sensitive C-reactive protein (US-CRP), cell activation markers, and plasma lipopolysaccharide (LPS) were analyzed.

Randomisation: Unrestricted randomisation.

Blinding: No blinding was used.

Results

Numbers randomised: Thirty recruited individuals were randomised to Thalidomide (16 patients) or Control (14 patients) groups.

Recruitment: Patients were recruited from April 2011 to January 2013.

Outcome: Viral loads remained stable in both groups. During thalidomide treatment, a decrease in CD4/CD8 ratio (p = 0.04), a decrease in CD4 count (p = 0.04), an increase in cell activation calculated by the percentage of CD38 ⁺/HLA-DR⁺ CD8 cells (p < 0.05) and an increase in US-CRP (p < 0.01) were observed in the Thalidomide group, with all parameters returning to baseline levels after thalidomide interruption. We confirmed that thalidomide increased HIV replication in vitro of 6 of 7 samples from long-term antiretroviral suppressed individuals.

Harms: No class 3/4 adverse events occurred.

Conclusions

Short-term use of thalidomide led to an intense transient increase in T cell activation and inflammation, with a decrease in the CD4⁺ cell count without changes to the CD8⁺ cell count. We confirmed that thalidomide acts in vitro as a latency reversal agent and speculate that the in vivo results obtained were due to an increase in HIV replication.

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Short-term Thalidomide use lead to intense increase in inflammatory markers among HIV+ antiretroviral naïve individuals.

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Thalidomide use lead to a transitory decrease in CD4⁺ T cells and CD4/CD8 ratios.

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In vitro complementary studies revealed that Thalidomide acts as an HIV Latency Reversal Agent.

Thalidomide in general presents a potent anti-inflammatory effect, and is still being used for a number of inflammatory diseases and infection. Therefore, Thalidomide investigated here in a randomised clinical trial aiming to mitigate HIV related inflammation among antiretroviral naïve individuals. Surprisingly, the HIV related inflammation increased during Thalidomide use, and in vitro studies demonstrated that Thalidomide is efficient in interrupting HIV latency, one of the major's obstacles for the cure of HIV chronic infection.

A Systematic Review of Immunological Studies of Erythema Nodosum Leprosum

Erythema nodosum leprosum (ENL) is a painful inflammatory complication of leprosy occurring in 50% of lepromatous leprosy patients and 5-10% of borderline lepromatous patients. It is a significant cause of economic hardship, morbidity and mortality in leprosy patients. Our understanding of the causes of ENL is limited. We performed a systematic review of the published literature and critically evaluated the evidence for the role of neutrophils, immune complexes (ICs), T-cells, cytokines, and other immunological factors that could contribute to the development of ENL. Searches of the literature were performed in PubMed. Studies, independent of published date, using samples from patients with ENL were included. The search revealed more than 20,000 articles of which 146 eligible studies were included in this systematic review. The studies demonstrate that ENL may be associated with a neutrophilic infiltrate, but it is not clear whether it is an IC-mediated process or that the presence of ICs is an epiphenomenon. Increased levels of tumor necrosis factor-α and other pro-inflammatory cytokines support the role of this cytokine in the inflammatory phase of ENL but not necessarily the initiation. T-cell subsets appear to be important in ENL since multiple studies report an increased CD4⁺/CD8⁺ ratio in both skin and peripheral blood of patients with ENL. Microarray data have identified new molecules and whole pathophysiological pathways associated with ENL and provides new insights into the pathogenesis of ENL. Studies of ENL are often difficult to compare due to a lack of case definitions, treatment status, and timing of sampling as well as the use of different laboratory techniques. A standardized approach to some of these issues would be useful. ENL appears to be a complex interaction of various aspects of the immune system. Rigorous clinical descriptions of well-defined cohorts of patients and a systems biology approach using available technologies such as genomics, epigenomics, transcriptomics, and proteomics could yield greater understanding of the condition.

The influence of innate and adaptative immune responses on the differential clinical outcomes of leprosy

Leprosy is a chronic infectious disease caused by Mycobacterium leprae. According to official reports from 121 countries across five WHO regions, there were 213 899 newly diagnosed cases in 2014. Although leprosy affects the skin and peripheral nerves, it can present across a spectrum of clinical and histopathological forms that are strongly influenced by the immune response of the infected individuals. These forms comprise the extremes of tuberculoid leprosy (TT), with a M. leprae-specific Th1, but also a Th17, response that limits M. leprae multiplication, through to lepromatous leprosy (LL), with M. leprae-specific Th2 and T regulatory responses that do not control M. leprae replication but rather allow bacterial dissemination. The interpolar borderline clinical forms present with similar, but less extreme, immune biases. Acute inflammatory episodes, known as leprosy reactions, are complications that may occur before, during or after treatment, and cause further neurological damages that can cause irreversible chronic disabilities. This review discusses the innate and adaptive immune responses, and their interactions, that are known to affect pathogenesis and influence the clinical outcome of leprosy.

Thalidomide attenuates the development and expression of antinociceptive tolerance to μ-opioid agonist morphine through l-arginine-iNOS and nitric oxide pathway

Morphine is a μ-opioid analgesic drug which is used in the treatment and management of chronic pain. However, due to development of antinociceptive tolerance its clinical use is limited. Thalidomide is an old glutamic acid derivative which recently reemerged because of its potential to counteract a number of disorders including neurodegenerative disorders. The potential underlying mechanisms and effects of thalidomide on morphine-induced antinociceptive tolerance is still elusive. Hence, the present study was designed to explore the effect of thalidomide on the development and expression of morphine antinociceptive tolerance targeting l-arginine-nitric oxide (NO) pathway in mice and T98G human glioblastoma cell line. When thalidomide was administered in a dose of 17.5mg/kg before each dose of morphine chronically for 5days it prevented the development of antinociceptive tolerance. Also, a single dose of thalidomide 20mg/kg attenuated the expression phase of antinociceptive tolerance. The protective effect of thalidomide was augmented in development phase when co-administration with NOS inhibitors like L-NAME (non- selective NOS inhibitor; 2mg/kg) or aminoguanidine (selective inducible NOS inhibitor; 50mg/kg). Also, the reversal effect of thalidomide in expression phase was potentiated when concomitantly administrated with L-NAME (5mg/kg) or aminoguanidine (100mg/kg). Co-administration of ODQ (a guanylyl cyclase inhibitor) 10mg/kg in developmental phase or 20mg/kg in expression phase also progressively increased the pain threshold. In addition, thalidomide (20μM) also significantly inhibited the overexpression of iNOS gene induced by morphine (2.5μM) in T98G cell line. Hence, our findings suggest that thalidomide has protective effect both in the development and expression phases of morphine antinociceptive tolerance. It is also evident that this effect of thalidomide is induced by the inhibition of NOS enzyme predominantly iNOS.

Angiogenesis: Basic Mechanisms and Clinical Applications

The development and maintenance of an adequate vascular supply is critical for the viability of normal and neoplastic tissues. Angiogenesis, the development of new blood vessels from preexisting capillary networks, plays an important role in a number of physiologic and pathologic processes, including reproduction, wound repair, inflammatory diseases, and tumor growth. Angiogenesis involves sequential steps that are triggered in response to angiogenic growth factors released by inflammatory, mesenchymal, or tumor cells that act as ligands for endothelial cell receptor tyrosine kinases. Stimulated endothelial cells detach from neighboring cells and migrate, proliferate, and form tubes. The immature tubes are subsequently invested and stabilized by pericytes or smooth muscle cells. Angiogenesis depends upon complex interactions among various classes of molecules, including adhesion molecules, proteases, structural proteins, cell surface receptors, and growth factors. The therapeutic manipulation of angiogenesis targeted against ischemic and neoplastic diseases has been investigated in preclinical animal models and in clinical trials. Proangiogenic trials that have stimulated vessel growth in ischemic coronary or peripheral tissues through expression, delivery, or stimulated release of growth factors have shown efficacy in animal models and mixed results in human clinical trials. Antiangiogenic trials have used strategies to block the function of molecules critical for new vessel growth or maturation in the treatment of a variety of malignancies, mostly with results less encouraging than those seen in preclinical models. Pro-and antiangiogenic clinical trials demonstrate that strategies for optimal drug delivery, dosing schedules, patient selection, and endpoint measurements need further investigation and refinement before the therapeutic manipulation of angiogenesis will realize its full clinical potential.

Urticaria as a Cutaneous Sign of Adult-Onset Still's Disease

Background:

The cardinal signs and symptoms of adult-onset Still's disease (AOSD) include periodic fever, arthralgia and arthritis, lymphadenopathy, hepatosplenomegaly, an evanescent rash accompanied by neutrophilic granulocytosis, and a negative rheumatoid factor and antinuclear antibody test.

Objective:

To alert clinicians and dermatologists to internal diseases such as AOSD when assisting patients with urticarial eruptions and systemic symptoms.

Methods:

A case report of a 52-year-old white woman who received conventional therapy for urticaria for 3 years, with no improvement. Following this period, a diagnosis of AOSD was performed based on the presence of systemic symptoms.

Results:

The inflammatory activity markers decreased by the second month of methotrexate therapy; however, the cutaneous lesions failed to disappear. Thalidomide was initiated, and total improvement of the cutaneous lesions was observed after 2 weeks.

Conclusion:

Urticarial rash is an uncommon presentation of AOSD, and clinicians must be alert to the possibility of a misdiagnosis in these cases.

Thalidomide analogues: Tumor necrosis factor-alpha inhibitors and their evaluation as anti-inflammatory agents

A series of related thalidomide derivatives (2-9) were synthesized by microwave irradiation and evaluated for anti-inflammatory activity. Such activity was assessed in vivo and ex vivo. Compounds 2, 8 and 9 showed the highest levels of inhibition of TNF-α production. On rat paw edema and hyperalgesia assays, compound 9, (1,4-phthalazinedione) demonstrated the highest in vivo anti-inflammatory activity. Thus, compound 9 can be considered as a promising compound to be subjected to further modification to obtain new agents for the treatment of inflammatory diseases.

Malignant causes of fever of unknown origin

The presence of fever in malignancy usually indicates infection, though transfusion, thrombosis and drugs are also culprits. However, particularly in some tumour types, fever can also be a paraneoplastic syndrome, caused by the malignancy itself. This can be a difficult diagnosis to establish and presents a therapeutic challenge to the physician when the underlying malignancy is not easily treated.

Design, synthesis and structure-activity relationship of phthalimides endowed with dual antiproliferative and immunomodulatory activities

The present work reports the synthesis and evaluation of the antitumour and immunomodulatory properties of new phthalimides derivatives designed to explore molecular hybridization and bioisosterism approaches between thalidomide, thiosemicarbazone, thiazolidinone and thiazole series. Twenty-seven new molecules were assessed for their immunosuppressive effect toward TNFα, IFNγ, IL-2 and IL-6 production and antiproliferative activity. The best activity profile was observed for the (6a-f) series, which presents phthalyl and thiazolidinone groups.

Discovery and structure-activity relationship studies of N6-benzoyladenine derivatives as novel BRD4 inhibitors

Bromodomain and extra-terminal domain (BET) proteins are epigenetic readers that bind to acetylated lysines in histones. Among them, BRD4 is a candidate target molecule of therapeutic agents for diverse diseases, including cancer and inflammatory disease. As a part of our continuing structural development studies of thalidomide to obtain a broad spectrum of biological modifiers based on the 'multi-template' approach, in this work we focused on BRD4-inhibitory activity, and discovered that N6-benzoyladenine derivatives exhibit this activity. Structure-activity relationship studies led to N6-(2,4,5-trimethoxybenzoyl)adenine (29), which exhibits potent BRD4 bromodomain1 inhibitory activity with an IC50 value of 0.427μM. N6-Benzoyladenine appears to be a new chemical scaffold for development of BRD4 inhibitors.

Treatment of cachexia: an overview of recent developments

Body wasting in the context of chronic illness is associated with reduced quality of life and impaired survival. Recent clinical trials have investigated different approaches to improve patients' skeletal muscle mass and strength, exercise capacity, and survival in the context of cachexia and body wasting, many of them in patients with cancer. The aim of this article was to summarize clinical trials published over the past 2 years. Therapeutic approaches discussed include appetite stimulants, such as megestrol acetate, L-carnitine, or melatonin, anti-inflammatory drugs, such as thalidomide, pentoxyphylline, or a monoclonal antibody against interleukin-1α as well as ghrelin and the ghrelin agonist anamorelin; nutritional support, and anabolics, such as enobosarm and testosterone.

Mechanisms and treatment of cancer cachexia

According to a recent consensus, cachexia is a complex metabolic syndrome associated with underlying illness and characterised by loss of muscle with or without loss of fat mass. The prominent clinical feature of cachexia is weight loss. Cachexia occurs in the majority of terminal cancer patients and it is responsible for the deaths of 22% of cancer patients. Although body weight is, indeed, an important factor to be taken into consideration in any cachexia treatment, body composition, physical performance and quality of life should be monitored. From the results presented here, one can speculate that a single therapy may not be completely successful in the treatment of cachexia. From this point of view, treatments involving different combinations are more likely to be successful. The objectives of any therapeutical combination are two: an anticatabolic aim directed towards both fat and muscle catabolism and an anabolic objective leading to the synthesis of macromolecules such as contractile proteins.

Thalidomide corrects impaired mesenchymal stem cell function in inducing tolerogenic DCs in patients with immune thrombocytopenia

Thalidomide (THD) is an immunomodulatory agent used to treat immune-mediated diseases. Immune thrombocytopenia (ITP) is an autoimmune disorder in which impaired mesenchymal stem cells (MSCs) are potentially involved. We demonstrated that MSCs in ITP patients had reduced proliferative capacity and lost their immunosuppressive function, which could be corrected with THD treatment. According to the gene profile, the downregulation of caspase-8 and caspase-10, and upregulation of oct3/4 and tgf-β1, may be associated with THD modulation. Dendritic cells (DCs) played an important role in mediating the inhibitory activity of MSCs. To study the functional alteration of DCs elicited by MSCs, we sorted DCs after incubation with MSCs and performed T-lymphocyte reaction assays. The THD-modulated MSCs from ITP patients induced mature DCs to become tolerogenic DCs, whereas unmodulated MSCs had no effect. The induction of tolerogenicity in DCs by MSCs was dependent on the expression of TIEG1 in DCs. The study reveals the inability of MSCs from ITP patients to induce tolerogenic ability in DCs. THD could restore the regulatory effect of MSCs on DCs. These findings will help us understand the pathogenesis of ITP, and with appropriate safeguards, THD may benefit patients with ITP.

Thalidomide suppresses inflammation in adenine-induced CKD with uraemia in mice

BACKGROUND

Persistent systemic inflammation has been widely recognized in patients with chronic kidney disease (CKD), and is associated with increased risk of morbidity and mortality. Intervention therapies aiming for the blockade of inflammatory cytokines are considered attractive approaches for CKD patients with signs of chronic inflammation. In this context, thalidomide, due to its potent anti-inflammatory and immunomodulatory properties, may represent an alternative strategy of treatment. In the present study, we developed an experimental model of CKD with uraemia in mice, induced by a diet rich in adenine, which causes progressive renal dysfunction, resembling the human uraemic features. Inflammatory parameters were analysed in this model of CKD and the potential beneficial effects of thalidomide as an anti-inflammatory drug was also investigated.

METHODS

C57/BL-6 mice were fed with an adenine-containing diet during a period of 6 weeks. Thirty mice were divided into three groups: Control group (animals receiving normal diet), ADE group (mice receiving adenine-containing diet) and ADE + TLD group (CKD mice receiving thalidomide, 30 mg/kg/day, by gavage). Besides biochemical and histopathological changes, local and systemic inflammatory parameters were also analysed, including expression of cytokines interleukin (IL)-1β, tumour necrosis factor-α, IL-6, IL-4 and IL-10 in kidney samples by real-time RT-PCR and quantification of serum levels of cytokines. Finally, the electrophoretic mobility shift assay (EMSA) for NF-κB was also examined.

RESULTS

Adenine-fed mice developed advanced CKD characterized by a marked increase in serum urea, creatinine, phosphorus and intact parathyroid hormone (iPTH) levels. In addition, histological changes of tubulointerstitial injury, characterized by deposition of crystals in the kidney, accompanied by tubular dilatation, degeneration of proximal tubular epithelium with loss of the brush border, inflammatory cellular infiltration, foreign-body granuloma formation and interstitial fibrosis were also evident. By immunohistochemistry, Mac-2- and α-SMA-positive cells were identified in the tubulointerstitial compartment. Treatment with thalidomide significantly reduced serum urea, creatinine, phosphorus and iPTH levels and protected against tubulointerstitial injury. Local and systemic inflammation in the mice model of adenine-induced CKD was confirmed by the findings of significantly high expression of cytokine mRNA levels and NF-κB activation in the kidney tissue as well as marked increased serum levels of inflammatory cytokines. Thalidomide treatment significantly reduced gene expression of these cytokines and the activation of the NF-κB in the renal tissue and the circulating levels of cytokines.

CONCLUSIONS

Dietary adenine caused advanced CKD with uraemia in mice providing a useful experimental model to study molecular and morphological changes associated with this disease. The negative impact of inflammation in this CKD model was overcome by the marked anti-inflammatory effects of thalidomide, promoting renal protection.

Leprous neuropathy

Leprous neuropathy, which is due to infection of nerve cells by Mycobacterium leprae, still affects millions of people in many developing countries. The clinical and pathological manifestations are determined by the natural resistance of the host to invasion of M. Leprae. Failure of early detection of leprosy often leads to severe disability in spite of eradication of mycobacterium at a later date. In the lepromatous type, bacilli are easily found in the skin and in nerve cells including Schwann cells, endothelial cells, and macrophages. In the tuberculoid type, a strong cell-mediated immune reaction leads to formation of granulomas and destruction of cells harboring bacilli and neighboring nerve fibers. In many cases, treatment of patients with the multibacillary leprosy is complicated by reversal reaction and further nerve damage. Nerve lesions lead to a symmetrical, pseudo-polyneuritic pattern in most cases of lepromatous leprosy, which is usually associated with typical skin lesions, but pure neuritic forms occur in up to 10% of patients with lepromatous leprosy. In the pure neuropathic cases, only nerve biopsy permits diagnosis. The multifocal pattern is more common in tuberculoid leprosy. Treatment is currently based on multidrug therapy with dapsone, rifampicin, and clofazimine. The use of corticosteroids can reduce or prevent nerve damage in reversal reactions. It is important to remember that sequelae, especially sensory loss, are extremely common, which can lead to secondary trophic changes due to repeated trauma in painless areas.

Thalidomide: an old drug with new action

Thalidomide is a drug that, since its development, has made history in the world of medicine--having been withdrawn and now has returned with a boom as an anticancer and immunomodulatory drug. However, its mode of action in various diseases (i.e. different types of hematologic malignancies, solid tumors) as well as in various infections (i.e. pneumonia, tuberculosis, HIV infection etc.) and related inflammatory conditions is not well understood. As the immune system plays an important role in the pathogenesis of both infection-related as well as noninfectious (i.e. cancer) inflammatory diseases, much research has been done in the past few years to discover and design better immunomodulatory agents. Such immunomodulatory agents should be able to target the immune system in such a way that host suffers minimum damage and normal function of the immune system remains intact. In the present review an attempt is made to highlight the immunomodulatory action of thalidomide in various pathologic conditions.

Immunotherapies in infectious diseases

The development of an infection involves interplay between the host's immune system and the virulence of the infecting microorganism. The traditional treatment of an infection involves antimicrobial chemotherapy to kill the organism. The use of immunotherapies in infections includes treatment options that modulate the immune response and can lead to control of infections. These therapies are expected to become more important therapeutic options with the increase in infections due to multidrug-resistant organisms and the increasing number of immunocompromised patients.

Thalidomide modulates Mycobacterium leprae-induced NF-κB pathway and lower cytokine response

It is widely accepted that tumor necrosis factor alpha (TNF-α) plays a critical role in the development of tissue and nerve damage in leprosy and during the reactional episodes of acute inflammation. Thalidomide (N-α-phthalimidoglutarimide), a drug used to treat leprosy reaction, modulates immune response, inhibits inflammation and NF-κB activity. Here we investigated whether thalidomide inhibits NF-κB activation induced by Mycobacterium leprae, p38 and ERK1/2 MAPK activation. EMSA and supershift assays were performed to investigate NF-κB activation in response to M. leprae and its modulation following in vitro treatment with thalidomide. Luciferase assay was assayed in transfected THP-1 cells to determine NF-κB transcriptional activity. Flow cytometry and immunofluorescence were used to investigate p65 accumulation in the nucleus. Immunoblotting was used to investigate p38 and ERK1/2 phosphorylation. Following activation of PBMC and monocytes with M. leprae, the formation and nuclear localization of NF-κB complexes composed mainly of p65/p50 and p50/p50 dimers was observed. Induction of NF-κB activation and DNA binding activity was inhibited by thalidomide. The drug also reduced M. leprae-induced TNF-α production and inhibited p38 and ERK1/2 activation. Definition of the activation mechanisms in cells stimulated with M. leprae can lead to the development of new therapy applications to modulate NF-κB activation and to control the inflammatory manifestations due to enhanced TNF-α response as observed in leprosy and in leprosy reactions.

[IMiDs in hematology]

IMiDs belong to a new pharmalogical class, whose principal therapeutic agents are the thalidomide and the lenalidomide. They have immunomodulatory and antiangiogenic properties, as well as a direct effect on tumor cells. Thalidomide and lenalidomide were first approved for multiple myeloma, and in 5q-myelodysplastic syndrome for lenalidomide. Several studies have shown the efficacy of these drugs in others hematologic malignancies. A third component has been developed, the pomalidomide, which may be more effective in certain indications. Here we present an overview of IMiDs in hematology, including mechanisms of action and known significant side effects.

Anti-inflammatory therapies in cancer cachexia

Disease progression in cancer is dependent on the complex interaction between the tumor and the host inflammatory response. Indeed, both the tumor and the patient produce cytokines that act on multiple target sites such as bone marrow, myocytes, hepatocytes, adipocytes, endothelial cells and neurons, where they produce a complex cascade of biological responses leading to the wasting associated with cachexia. The cytokines that have been involved in this cachectic response are TNF-alpha, IL-1, IL-6 and interferon-gamma. Interestingly, these cytokines share the same metabolic effects and their activities are closely interrelated. In many cases these cytokines exhibit synergic effects when administered together. Therefore, therapeutic strategies - either nutritional or pharmacological - have been based on either blocking their synthesis or their action.

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.