The role of interleukin-1 beta in the pathogenesis of multiple myeloma

IL1B Polymorphism (rs1143634) and IL-1β Plasma Concentration as Predictors of Nutritional Disorders and Prognostic Factors in Multiple Myeloma Patients

BACKGROUND

Multiple myeloma (MM) is a hematological neoplasm of the early precursor of B-cells. The most characteristic symptoms observed during MM include hypocalcemia, anemia, bacterial infections, and renal damage. Nutritional disorders, especially malnutrition, are noted in about 35-71% of MM patients. Interleukin 1 beta (IL-1β) is a proinflammatory cytokine responsible for muscle atrophy and lipolysis during malnutrition and cachexia. This study aimed to evaluate the usefulness of the IL1B single-nucleotide polymorphism (SNP) (rs1143634) and plasma concentration of IL-1β in the assessment of the risk of nutritional disorders and prognosis in patients with MM.

METHODS

In our study, 93 patients with the de novo MM were enrolled. The real-time PCR with specific TaqMan probes method was used in genotyping. The IL-1β ELISA kit was used to determine IL-1β concentration in plasma samples.

RESULTS

Patients with the CC genotype, compared to the carriers of the other variants of the IL1B, demonstrated significantly higher concentrations of IL-1β in plasma (7.56 vs. 4.97 pg/mL), a significantly higher risk of cachexia (OR = 5.11), and a significantly higher risk of death (HR = 2.03). Moreover, high IL-1β plasma level was related to a significantly higher risk of cachexia (OR = 7.76); however, it was not significantly associated with progression-free survival (PFS) or overall survival (OS).

CONCLUSIONS

Determination of the IL1B SNP (rs1143634) and plasma concentration of IL-1β may be useful in the assessment of the risk of cachexia and prognosis in patients with MM.

Unraveling the Role of the NLRP3 Inflammasome in Lymphoma: Implications in Pathogenesis and Therapeutic Strategies

Inflammasomes are multimeric protein complexes, sensors of intracellular danger signals, and crucial components of the innate immune system, with the NLRP3 inflammasome being the best characterized among them. The increasing scientific interest in the mechanisms interconnecting inflammation and tumorigenesis has led to the study of the NLRP3 inflammasome in the setting of various neoplasms. Despite a plethora of data regarding solid tumors, NLRP3 inflammasome's implication in the pathogenesis of hematological malignancies only recently gained attention. In this review, we investigate its role in normal lymphopoiesis and lymphomagenesis. Considering that lymphomas comprise a heterogeneous group of hematologic neoplasms, both tumor-promoting and tumor-suppressing properties were attributed to the NLRP3 inflammasome, affecting neoplastic cells and immune cells in the tumor microenvironment. NLRP3 inflammasome-related proteins were associated with disease characteristics, response to treatment, and prognosis. Few studies assess the efficacy of NLRP3 inflammasome therapeutic targeting with encouraging results, though most are still at the preclinical level. Further understanding of the mechanisms regulating NLRP3 inflammasome activation during lymphoma development and progression can contribute to the investigation of novel treatment approaches to cover unmet needs in lymphoma therapeutics.

NLRP3 and cancer: Pathogenesis and therapeutic opportunities

More than a decade ago IL-1 blockade was suggested as an add-on therapy for the treatment of cancer. This proposal was based on the overall safety record of anti-IL-1 biologics and the anti-tumor properties of IL-1 blockade in animal models of cancer. Today, a new frontier in IL-1 activity regulation has developed with several orally active NLRP3 inhibitors currently in clinical trials, including cancer. Despite an increasing body of evidence suggesting a role of NLRP3 and IL-1-mediated inflammation driving cancer initiation, immunosuppression, growth, and metastasis, NLRP3 activation in cancer remains controversial. In this review, we discuss the recent advances in the understanding of NLRP3 activation in cancer. Further, we discuss the current opportunities for NLRP3 inhibition in cancer intervention with novel small molecules.

Therapeutic effect of trace elements on multiple myeloma and mechanisms of cancer process

In the human body, trace elements and other micronutrients play a vital role in growth, health and immune system function. The trace elements are Iron, Manganese, Copper, Iodine, Zinc, Cobalt, Fluoride, and Selenium. Estimating the serum levels of trace elements in hematologic malignancy patients can determine the severity of the tumor. Multiple myeloma (MM) is a hematopoietic malignancy and is characterized by plasma cell clonal expansion in bone marrow. Despite the advances in treatment methods, myeloma remains largely incurable. In addition to conventional medicine, treatment is moving toward less expensive noninvasive alternatives. One of the alternative treatments is the use of dietary supplements. In this review, we focused on the effect of three trace elements including iron, zinc and selenium on important mechanisms such as the immune system, oxidative and antioxidant factors and cell cycle. Using some trace minerals in combination with approved drugs can increase patients' recovery speed. Trace elements can be used as not only a preventive but also a therapeutic tool, especially in reducing inflammation in hematological cancers such as multiple myeloma. We hope that the prospect of the correct use of trace element supplements in the future could be promising for the treatment of diseases.

β2-microglobulin triggers NLRP3 inflammasome activation in tumor-associated macrophages to promote multiple myeloma progression

As substantial constituents of the multiple myeloma (MM) microenvironment, pro-inflammatory macrophages have emerged as key promoters of disease progression, bone destruction, and immune impairment. We identify beta-2-microglobulin (β2m) as a driver in initiating inflammation in myeloma-associated macrophages (MAMs). Lysosomal accumulation of phagocytosed β2m promotes β2m amyloid aggregation in MAMs, resulting in lysosomal rupture and ultimately production of active interleukin-1β (IL-1β) and IL-18. This process depends on activation of the NLRP3 inflammasome after β2m accumulation, as macrophages from NLRP3-deficient mice lack efficient β2m-induced IL-1β production. Moreover, depletion or silencing of β2m in MM cells abrogates inflammasome activation in a murine MM model. Finally, we demonstrate that disruption of NLRP3 or IL-18 diminishes tumor growth and osteolytic bone destruction normally promoted by β2m-induced inflammasome signaling. Our results provide mechanistic evidence for β2m's role as an NLRP3 inflammasome activator during MM pathogenesis. Moreover, inhibition of NLRP3 represents a potential therapeutic approach in MM.

Interleukin-1β is a potential therapeutic target for periodontitis: a narrative review

Interleukin(IL)-1β, a pro-inflammatory cytokine, was elevated and participates in periodontitis. Not only the link between IL-1β and periodontitis was proved by clinical evidence, but also the increased IL-1β triggers a series of inflammatory reactions and promotes bone resorption. Currently, IL-1β blockage has been therapeutic strategies for autoimmune and autoinflammatory diseases such as rheumatoid arthritis, cryopyrin-associated periodic syndromes, gout and type II diabetes mellitus. It is speculated that IL-1β be a potential therapeutic target for periodontitis. The review focuses on the production, mechanism, present treatments and future potential strategies for IL-1β in periodontitis.

Inflammasome inhibitors: promising therapeutic approaches against cancer

Inflammation has long been accepted as a key component of carcinogenesis. During inflammation, inflammasomes are potent contributors to the activation of inflammatory cytokines that lead to an inflammatory cascade. Considering the contributing role of inflammasomes in cancer progression, inflammasome inhibitors seem to have a promising future in cancer treatment and prevention. Here, we summarize the structures and signaling pathways of inflammasomes and detail some inflammasome inhibitors used to treat various forms of cancer, which we expect to be used in novel anticancer approaches. However, the practical application of inflammasome inhibitors is limited in regard to specific types of cancer, and the associated clinical trials have not yet been completed. Therefore, additional studies are required to explore more innovative and effective medicines for future clinical treatment of cancer.

The emerging roles of inflammasome-dependent cytokines in cancer development

In addition to the genomic alterations that occur in malignant cells, the immune system is increasingly appreciated as a critical axis that regulates the rise of neoplasms and the development of primary tumours and metastases. The interaction between inflammatory cell infiltrates and stromal cells in the tumour microenvironment is complex, with inflammation playing both pro- and anti-tumorigenic roles. Inflammasomes are intracellular multi-protein complexes that act as key signalling hubs of the innate immune system. They respond to cellular stress and trauma by promoting activation of caspase-1, a protease that induces a pro-inflammatory cell death mode termed pyroptosis along with the maturation and secretion of the pro-inflammatory cytokines interleukin (IL)-1β and IL-18. Here, we will briefly introduce inflammasome biology with a focus on the dual roles of inflammasome-produced cytokines in cancer development. Despite emerging insight that inflammasomes may promote and suppress cancer development according to the tumour stage and the tumour microenvironment, much remains to be uncovered. Further exploration of inflammasome biology in tumorigenesis should enable the development of novel immunotherapies for cancer patients.

Treatment of Inflammatory Diseases with IL-1 Blockade

Background

Autoinflammatory diseases are distinct from autoimmune diseases. Whereas autoinflammatory diseases are due to dysfunctional T-cells and B-cells, autoinflammatory diseases are due to overproduction of macrophage cytokines particularly interleukin-1 beta (IL-1β). A causative role for IL-1 in autoinflammatory diseases is derived from clinical studies blocking the IL-1 receptor or neutralizing monoclonal antibodies or soluble receptors.

Methods

A review was performed of clinical trials in autoinflammatory diseases using the IL-1 receptor antagonist (anakinra), the soluble IL-1 receptor (rilonacept), antibodies to IL-1β (canakinumab, gevokizumab) and anti-IL-1α (xilonix).

Findings

Anakinra blocks the IL-1 Receptor type 1 (IL-1R1) and therefore blocks the activities of both IL-1α and IL-1β. Off-label use of anakinra is common for a broad spectrum of inflammatory diseases. Neutralization of IL-1β is used to treat hereditary autoinflammatory diseases but also atherosclerosis. Rilonacept reduces arterial wall inflammation in patients with chronic kidney disease. Neutralization of IL-1α has prolonged life in patients with advanced metastatic colorectal cancer. Compared to other cytokine blocking therapies, reducing the activities of IL-1 has an excellent safety record.

Conclusions

Blocking IL-1 therapies can be used to treat a wide-spectrum of acute and chronic inflammatory diseases.

Serum Levels of Leptin in Multiple Myeloma Patients and Its Relation to Angiogenic and Inflammatory Cytokines

Background

Leptin, apart from the regulation of food intake, has been implicated in hematopoiesis, the immune response and angiogenesis. Leptin has been found to be decreased in various hematological malignancies. In the present study leptin was measured in multiple myeloma (MM) patients before and after treatment and correlated with other angiogenic molecules and markers of disease activity.

Methods

Serum leptin, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (b-FGF), interleukin-1 beta (IL-1β), beta 2 microglobulin (β2M) and C-reactive protein (CRP) were measured in 62 newly diagnosed MM patients, 22 of whom obtaining disease stabilization after treatment. The same parameters were measured in 20 healthy controls. Disease stage was defined according to the Durie-Salmon criteria.

Results

Leptin, VEGF, b-FGF, IL-1β, and β2M were significantly higher in newly diagnosed MM patients than in controls (p<0.05). VEGF, b-FGF, IL-1β, β2M, CRP but not leptin increased with advancing stage of disease (p<0.01). All parameters decreased significantly following treatment (p<0.001). Although IL-1β correlated positively with VEGF, β2M, b-FGF and CRP, leptin did not correlate with any of the measured parameters.

Conclusion

Leptin serum levels do not reflect disease severity in MM. However, there seems to be a decrease in leptin following treatment, which may be associated with an alteration in the metabolic state or the chemokine milieu.

Overview of the IL-1 family in innate inflammation and acquired immunity

The interleukin-1 (IL-1) family of cytokines and receptors is unique in immunology because the IL-1 family and Toll-like receptor (TLR) families share similar functions. More than any other cytokine family, the IL-1 family is primarily associated with innate immunity. More than 95% of living organisms use innate immune mechanisms for survival whereas less than 5% depend on T- and B-cell functions. Innate immunity is manifested by inflammation, which can function as a mechanism of host defense but when uncontrolled is detrimental to survival. Each member of the IL-1 receptor and TLR family contains the cytoplasmic Toll-IL-1-Receptor (TIR) domain. The 50 amino acid TIR domains are highly homologous with the Toll protein in Drosophila. The TIR domain is nearly the same and present in each TLR and each IL-1 receptor family. Whereas IL-1 family cytokine members trigger innate inflammation via IL-1 family of receptors, TLRs trigger inflammation via bacteria, microbial products, viruses, nucleic acids, and damage-associated molecular patterns (DAMPs). In fact, IL-1 family member IL-1a and IL-33 also function as DAMPs. Although the inflammatory properties of the IL-1 family dominate in innate immunity, IL-1 family member can play a role in acquired immunity. This overview is a condensed update of the IL-1 family of cytokines and receptors.

Interleukins 1 and 6 as Main Mediators of Inflammation and Cancer

The idea of a potential link between cancer and inflammation was first proposed by R. Virchow in the nineteenth century. However, clear evidence regarding a key role of inflammation in oncogenesis appeared only during the last decade. Now the tumor microenvironment is commonly considered as an obligatory and significant component of almost all types of cancer, and the cells infiltrating such microenvironment are a source of inflammatory cytokines. Such cytokines play a key role in regulating inflammation during both normal immune response and developing cancer. In this review, we explore the role of two inflammatory cytokines interleukin 1 and interleukin 6 in cancer development. These cytokines have pleiotropic effects on various cell types in the tumor microenvironment, particularly being able to regulate pro-oncogenic transcription factors NF-κB and STAT3. For this reason, such cytokines influence key parameters of oncogenesis, increasing cell resistance to apoptosis, proliferation of cancer cells, angiogenesis, invasion and malignancy as well as the ability of tumor cells to respond to anticancer therapy. Here we summarize novel experimental data regarding mechanisms underlying the interaction between chronic inflammation and malignant neoplasms.

The evaluation of NT-proCNP, C-reactive protein and serum amyloid A protein concentration in patients with multiple myeloma undergoing stem cell transplantation

The importance of proinflamatory cytokines and acute phase proteins in pathogenesis and progression of MM is well known. However, there are any studies evaluating the role of NT-proCN in management and treatment of MM. The aim of our study was to evaluate the concentration of NT-proCNP and acute phase proteins in patients with MM before and after stem cell transplantation. We involved 40 newly diagnosed MM patients in stage III according to the Durie-Salmon classification and treated with high dose of melphalan (200mg/m2) prior to ASCT. Concentration of NT-proCNP, hs-CRP and SAA were measured before conditioning treatment and every 4days until the 24th day after stem cell infusion. We observed low NT-proCNP levels before conditioning treatment (0.121±0.04pmol/l), the higher in day on ASCT (0.28±0.14pmol/l). Further we showed significant gradual increase concentration of NT-proCNP up to 12days after stem cells infusion (1.07±0.72pmol/l). The kinetics of hs-CRP and SAA levels were similar to NT-proCNP. We showed positive correlation between NT-proCNP levels and absolute neutrophil and platelets count in patients after ASCT. NT-proCNP can be useful parameter to assess effectiveness of treatment and monitoring of hematopoetic recovery time in patients with MM after stem cell transplantations.

Gaucher iPSC-derived macrophages produce elevated levels of inflammatory mediators and serve as a new platform for therapeutic development

Gaucher disease (GD) is an autosomal recessive disorder caused by mutations in the acid β-glucocerebrosidase (GCase; GBA) gene. The hallmark of GD is the presence of lipid-laden Gaucher macrophages, which infiltrate bone marrow and other organs. These pathological macrophages are believed to be the sources of elevated levels of inflammatory mediators present in the serum of GD patients. The alteration in the immune environment caused by GD is believed to play a role in the increased risk of developing multiple myeloma and other malignancies in GD patients. To determine directly whether Gaucher macrophages are abnormally activated and whether their functional defects can be reversed by pharmacological intervention, we generated GD macrophages by directed differentiation of human induced pluripotent stem cells (hiPSC) derived from patients with types 1, 2, and 3 GD. GD hiPSC-derived macrophages expressed higher levels of tumor necrosis factor α, IL-6, and IL-1β than control cells, and this phenotype was exacerbated by treatment with lipopolysaccharide. In addition, GD hiPSC macrophages exhibited a striking delay in clearance of phagocytosed red blood cells, recapitulating the presence of red blood cell remnants in Gaucher macrophages from bone marrow aspirates. Incubation of GD hiPSC macrophages with recombinant GCase, or with the chaperones isofagomine and ambroxol, corrected the abnormal phenotypes of GD macrophages to an extent that reflected their known clinical efficacies. We conclude that Gaucher macrophages are the likely source of the elevated levels of inflammatory mediators in the serum of GD patients and that GD hiPSC are valuable new tools for studying disease mechanisms and drug discovery.

Pulmonary hypertension complicating multiple myeloma

Pulmonary hypertension (PH) is an infrequently reported complication of multiple myeloma (MM). PH has been more commonly associated with amyloidosis, myeloproliferative diseases, and the POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes) syndrome. PH in MM is typically mild to moderate and may be secondary to a variety of conditions, which include left ventricular dysfunction, high-output cardiac failure, chronic kidney disease, treatment-related toxicities, and precapillary involvement. We describe 3 patients with MM and severe PH. Each patient underwent right heart catheterization. All patients demonstrated elevated pulmonary pressures, transpulmonary gradients, and pulmonary vascular resistance. Each patient was ultimately treated with pulmonary vasodilator therapy with improvement in cardiopulmonary symptoms. Additional studies are needed to define the prevalence, prognosis, and pathogenesis of PH in this complex population and to help clarify who may benefit from targeted PH therapy.

Immunomodulatory effects of the Agaricus blazei Murrill-based mushroom extract AndoSan in patients with multiple myeloma undergoing high dose chemotherapy and autologous stem cell transplantation: a randomized, double blinded clinical study

Forty patients with multiple myeloma scheduled to undergo high dose chemotherapy with autologous stem cell support were randomized in a double blinded fashion to receive adjuvant treatment with the mushroom extract AndoSan, containing 82% of Agaricus blazei Murrill (19 patients) or placebo (21 patients). Intake of the study product started on the day of stem cell mobilizing chemotherapy and continued until the end of aplasia after high dose chemotherapy, a period of about seven weeks. Thirty-three patients were evaluable for all study endpoints, while all 40 included patients were evaluable for survival endpoints. In the leukapheresis product harvested after stem cell mobilisation, increased percentages of Treg cells and plasmacytoid dendritic cells were found in patients receiving AndoSan. Also, in this group, a significant increase of serum levels of IL-1ra, IL-5, and IL-7 at the end of treatment was found. Whole genome microarray showed increased expression of immunoglobulin genes, Killer Immunoglobulin Receptor (KIR) genes, and HLA genes in the Agaricus group. Furthermore, AndoSan displayed a concentration dependent antiproliferative effect on mouse myeloma cells in vitro. There were no statistically significant differences in treatment response, overall survival, and time to new treatment. The study was registered with Clinicaltrials.gov NCT00970021.

An expanding role for interleukin-1 blockade from gout to cancer

There is an expanding role for interleukin (IL)-1 in diseases from gout to cancer. More than any other cytokine family, the IL-1 family is closely linked to innate inflammatory and immune responses. This linkage is because the cytoplasmic segment of all members of the IL-1 family of receptors contains a domain, which is highly homologous to the cytoplasmic domains of all toll-like receptors (TLRs). This domain, termed "toll IL-1 receptor (TIR) domain," signals as does the IL-1 receptors; therefore, inflammation due to the TLR and the IL-1 families is nearly the same. Fundamental responses such as the induction of cyclo-oxygenase type 2, increased surface expression of cellular adhesion molecules and increased gene expression of a broad number of inflammatory molecules characterizes IL-1 signal transduction as it does for TLR agonists. IL-1β is the most studied member of the IL-1 family because of its role in mediating autoinflammatory disease. However, a role for IL-1α in disease is being validated because of the availability of a neutralizing monoclonal antibody to human IL-1α. There are presently three approved therapies for blocking IL-1 activity. Anakinra is a recombinant form of the naturally occurring IL-1 receptor antagonist, which binds to the IL-1 receptor and prevents the binding of IL-1β as well as IL-1α. Rilonacept is a soluble decoy receptor that neutralizes primarily IL-1β but also IL-1α. Canakinumab is a human monoclonal antibody that neutralizes only IL-1β. Thus, a causal or significant contributing role can be established for IL-1β and IL-1α in human disease.

Increased osteoclastogenesis in mice lacking the carcinoembryonic antigen-related cell adhesion molecule 1

Alterations in bone remodeling are a major public health issue, as therapeutic options for widespread bone disorders such as osteoporosis and tumor-induced osteolysis are still limited. Therefore, a detailed understanding of the regulatory mechanism governing bone cell differentiation in health and disease are of utmost clinical importance. Here we report a novel function of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), a member of the immunoglobulin superfamily involved in inflammation and tumorigenesis, in the physiologic regulation of bone remodeling. Assessing the expression of all members of the murine Ceacam family in bone tissue and marrow, we found CEACAM1 and CEACAM10 to be differentially expressed in both bone-forming osteoblasts and bone-resorbing osteoclasts. While Ceacam10-deficient mice displayed no alteration in structural bone parameters, static histomorphometry demonstrated a reduced trabecular bone mass in mice lacking CEACAM1. Furthermore, cellular and dynamic histomorphometry revealed an increased osteoclast formation in Ceacam1-deficient mice, while osteoblast parameters and the bone formation rate remained unchanged. In line with these findings, we detected accelerated osteoclastogenesis in Ceacam1-deficient bone marrow cells, while osteoblast differentiation, as determined by mineralization and alkaline phosphatase assays, was not affected. Therefore, our results provide in vivo and in vitro evidence for a physiologic role of CEACAM1 in the regulation of osteoclastogenesis.

TPL2 kinase regulates the inflammatory milieu of the myeloma niche

Targeted modulation of microenvironmental regulatory pathways may be essential to control myeloma and other genetically/clonally heterogeneous cancers. Here we report that human myeloma-associated monocytes/macrophages (MAM), but not myeloma plasma cells, constitute the predominant source of interleukin-1β (IL-1β), IL-10, and tumor necrosis factor-α at diagnosis, whereas IL-6 originates from stromal cells and macrophages. To dissect MAM activation/cytokine pathways, we analyzed Toll-like receptor (TLR) expression in human myeloma CD14(+) cells. We observed coregulation of TLR2 and TLR6 expression correlating with local processing of versican, a proteoglycan TLR2/6 agonist linked to carcinoma progression. Versican has not been mechanistically implicated in myeloma pathogenesis. We hypothesized that the most readily accessible target in the versican-TLR2/6 pathway would be the mitogen-activated protein 3 (MAP3) kinase, TPL2 (Cot/MAP3K8). Ablation of Tpl2 in the genetically engineered in vivo myeloma model, Vκ*MYC, led to prolonged disease latency associated with plasma cell growth defect. Tpl2 loss abrogated the "inflammatory switch" in MAM within nascent myeloma lesions and licensed macrophage repolarization in established tumors. MYC activation/expression in plasma cells was independent of Tpl2 activity. Pharmacologic TPL2 inhibition in human monocytes led to dose-dependent attenuation of IL-1β induction/secretion in response to TLR2 stimulation. Our results highlight a TLR2/6-dependent TPL2 pathway as novel therapeutic target acting nonautonomously through macrophages to control myeloma progression.

A novel human anti-interleukin-1β neutralizing monoclonal antibody showing in vivo efficacy

The pro-inflammatory cytokine interleukin (IL)-1β is a clinical target in many conditions involving dysregulation of the immune system; therapeutics that block IL-1β have been approved to treat diseases such as rheumatoid arthritis (RA), neonatal onset multisystem inflammatory diseases, cryopyrin-associated periodic syndromes, active systemic juvenile idiopathic arthritis. Here, we report the generation and engineering of a new fully human antibody that binds tightly to IL-1β with a neutralization potency more than 10 times higher than that of the marketed antibody canakinumab. After affinity maturation, the derived antibody shows a>30-fold increased affinity to human IL-1β compared with its parent antibody. This anti-human IL-1β IgG also cross-reacts with mouse and monkey IL-1β, hence facilitating preclinical development. In a number of mouse models, this antibody efficiently reduced or abolished signs of disease associated with IL-1β pathology. Due to its high affinity for the cytokine and its potency both in vitro and in vivo, we propose that this novel fully human anti-IL-1β monoclonal antibody is a promising therapeutic candidate and a potential alternative to the current therapeutic arsenal.

Arsenic trioxide and other arsenical compounds inhibit the NLRP1, NLRP3, and NAIP5/NLRC4 inflammasomes

Inflammasomes are large cytoplasmic multiprotein complexes that activate caspase-1 in response to diverse intracellular danger signals. Inflammasome components termed nucleotide-binding oligomerization domain-like receptor (NLR) proteins act as sensors for pathogen-associated molecular patterns, stress, or danger stimuli. We discovered that arsenicals, including arsenic trioxide and sodium arsenite, inhibited activation of the NLRP1, NLRP3, and NAIP5/NLRC4 inflammasomes by their respective activating signals, anthrax lethal toxin, nigericin, and flagellin. These compounds prevented the autoproteolytic activation of caspase-1 and the processing and secretion of IL-1β from macrophages. Inhibition was independent of protein synthesis induction, proteasome-mediated protein breakdown, or kinase signaling pathways. Arsenic trioxide and sodium arsenite did not directly modify or inhibit the activity of preactivated recombinant caspase-1. Rather, they induced a cellular state inhibitory to both the autoproteolytic and substrate cleavage activities of caspase-1, which was reversed by the reactive oxygen species scavenger N-acetylcysteine but not by reducing agents or NO pathway inhibitors. Arsenicals provided protection against NLRP1-dependent anthrax lethal toxin-mediated cell death and prevented NLRP3-dependent neutrophil recruitment in a monosodium urate crystal inflammatory murine peritonitis model. These findings suggest a novel role in inhibition of the innate immune response for arsenical compounds that have been used as therapeutics for a few hundred years.

Treating inflammation by blocking interleukin-1 in humans

IL-1 is a master cytokine of local and systemic inflammation. With the availability of specific IL-1 targeting therapies, a broadening list of diseases has revealed the pathologic role of IL-1-mediated inflammation. Although IL-1, either IL-1α or IL-1β, was administered to patients in order to improve bone marrow function or increase host immune responses to cancer, these patients experienced unacceptable toxicity with fever, anorexia, myalgias, arthralgias, fatigue, gastrointestinal upset and sleep disturbances; frank hypotension occurred. Thus it was not unexpected that specific pharmacological blockade of IL-1 activity in inflammatory diseases would be beneficial. Monotherapy blocking IL-1 activity in a broad spectrum of inflammatory syndromes results in a rapid and sustained reduction in disease severity. In common conditions such as heart failure and gout arthritis, IL-1 blockade can be effective therapy. Three IL-1blockers have been approved: the IL-1 receptor antagonist, anakinra, blocks the IL-1 receptor and therefore reduces the activity of IL-1α and IL-1β. A soluble decoy receptor, rilonacept, and a neutralizing monoclonal anti-interleukin-1β antibody, canakinumab, are also approved. A monoclonal antibody directed against the IL-1 receptor and a neutralizing anti-IL-1α are in clinical trials. By specifically blocking IL-1, we have learned a great deal about the role of this cytokine in inflammation but equally important, reducing IL-1 activity has lifted the burden of disease for many patients.

Solitary Plasmacytoma in the Setting of Langerhans Cell Histiocytosis

Langerhans cell histiocytosis (LCH) is an intriguing disorder characterized by the accumulation of specialized dendritic cells called Langerhans cells in several diverse tissues and body sites. It has been cited in numerous case reports to be associated with a wide variety of malignant neoplasms. Although many hypotheses have been suggested, the basis for such associations remains essentially unknown. We describe another association here that to our knowledge has not been reported thus far: a solitary plasmacytoma occurring at a site of previous involvement by LCH. This constitutes a new addition to the now fairly lengthy list of malignant neoplasms that have been reported to occur in the setting of LCH. The possible reasons for such an association are discussed along with a brief review of LCH.

Adenosine regulates bone metabolism via A1, A2A, and A2B receptors in bone marrow cells from normal humans and patients with multiple myeloma

Multiple myeloma (MM) is characterized by osteolytic bone lesions with uncoupled bone remodeling. In this study, we examined the effects of adenosine and its receptors (A1R, A2AR, A2BR, and A3R) on osteoblast and osteoclast differentiation of cells derived from patients with MM and healthy control subjects. Mesenchymal stem cells and bone marrow-derived mononuclear cells were isolated from bone marrow and differentiated into osteoblasts and osteoclasts, respectively. A1R antagonist rolofylline and A2BR agonist BAY60-6583 inhibit osteoclast differentiation of cells from patients with MM in a dose-dependent manner, as shown by TRAP staining (IC50: 10 and ∼10 nM, respectively). BAY60-6583 and dipyridamole, a nucleoside transport inhibitor, stimulate osteoblast differentiation of cells from patients with MM, as measured by ALP activity at d 14 and Alizarin Red staining at d 21 (by 1.57±0.03- and 1.71±0.45-fold, respectively), which can be blocked by A2BR antagonist MRS1754. Consistently, real-time PCR showed a significant increase of mRNA of osteocalcin and osterix at d 14. The effect of adenosine and its receptors is consistent in patients with MM and healthy subjects, suggesting an intrinsic mechanism that is important in both MM bone metabolism and normal physiology. Furthermore, the effect of dipyridamole on osteoblast differentiation is diminished in both A2BR- and CD39-knockout mice. These results indicate that adenosine receptors may be useful targets for the treatment of MM-induced bone disease.

Treating inflammation by blocking interleukin-1 in a broad spectrum of diseases

Interleukin-1 (IL-1) is a highly active pro-inflammatory cytokine that lowers pain thresholds and damages tissues. Monotherapy blocking IL-1 activity in autoinflammatory syndromes results in a rapid and sustained reduction in disease severity, including reversal of inflammation-mediated loss of sight, hearing and organ function. This approach can therefore be effective in treating common conditions such as post-infarction heart failure, and trials targeting a broad spectrum of new indications are underway. So far, three IL-1-targeted agents have been approved: the IL-1 receptor antagonist anakinra, the soluble decoy receptor rilonacept and the neutralizing monoclonal anti-IL-1β antibody canakinumab. In addition, a monoclonal antibody directed against the IL-1 receptor and a neutralizing anti-IL-1α antibody are in clinical trials.

A clinical perspective of IL-1β as the gatekeeper of inflammation

An expanding spectrum of acute and chronic non-infectious inflammatory diseases is uniquely responsive to IL-1β neutralization. IL-1β-mediated diseases are often called "auto-inflammatory" and the dominant finding is the release of the active form of IL-1β driven by endogenous molecules acting on the monocyte/macrophage. IL-1β activity is tightly controlled and requires the conversion of the primary transcript, the inactive IL-1β precursor, to the active cytokine by limited proteolysis. Limited proteolysis can take place extracellularly by serine proteases, released in particular by infiltrating neutrophils or intracellularly by the cysteine protease caspase-1. Therefore, blocking IL-1β resolves inflammation regardless of how the cytokine is released from the cell or how the precursor is cleaved. Endogenous stimulants such as oxidized fatty acids and lipoproteins, high glucose concentrations, uric acid crystals, activated complement, contents of necrotic cells, and cytokines, particularly IL-1 itself, induce the synthesis of the inactive IL-1β precursor, which awaits processing to the active form. Although bursts of IL-1β precipitate acute attacks of systemic or local inflammation, IL-1β also contributes to several chronic diseases. For example, ischemic injury, such as myocardial infarction or stroke, causes acute and extensive damage, and slowly progressive inflammatory processes take place in atherosclerosis, type 2 diabetes, osteoarthritis and smoldering myeloma. Evidence for the involvement of IL-1β and the clinical results of reducing IL-1β activity in this broad spectrum of inflammatory diseases are the focus of this review.

Role of IL-1 beta in the development of human T(H)17 cells: lesson from NLPR3 mutated patients

BACKGROUND

T helper 17 cells (T(H)-17) represent a lineage of effector T cells critical in host defence and autoimmunity. In both mouse and human IL-1β has been indicated as a key cytokine for the commitment to T(H)-17 cells. Cryopyrin-associated periodic syndromes (CAPS) are a group of inflammatory diseases associated with mutations of the NLRP3 gene encoding the inflammasome component cryopyrin. In this work we asked whether the deregulated secretion of IL-1β secondary to mutations characterizing these patients could affect the IL-23/IL-17 axis.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 11 CAPS, 26 systemic onset juvenile idiopathic arthritis (SoJIA) patients and 20 healthy controls were analyzed. Serum levels of IL-17 and IL-6 serum were assessed by ELISA assay. Frequency of T(H)17 cells was quantified upon staphylococcus enterotoxin B (SEB) stimulation. Secretion of IL-1β, IL-23 and IL-6 by monocyte derived dendritic cells (MoDCs), were quantified by ELISA assay. A total of 8 CAPS and 11 SoJIA patients were also analysed before and after treatment with IL-1β blockade. Untreated CAPS patients showed significantly increased IL-17 serum levels as well as a higher frequency of T(H)17 compared to control subjects. On the contrary, SoJIA patients displayed a frequency of T(H)17 similar to normal donors, but were found to have significantly increased serum level of IL-6 when compared to CAPS patients or healthy donors. Remarkably, decreased IL-17 serum levels and T(H)17 frequency were observed in CAPS patients following in vivo IL-1β blockade. On the same line, MoDCs from CAPS patients exhibited enhanced secretion of IL-1β and IL-23 upon TLRs stimulation, with a reduction after anti-IL-1 treatment.

CONCLUSION/SIGNIFICANCE

These findings further support the central role of IL-1β in the differentiation of T(H)17 in human inflammatory conditions.

Histone deacetylase inhibitors for treating a spectrum of diseases not related to cancer

This issue of Molecular Medicine contains 14 original research reports and state-of-the-art reviews on histone deacetylase inhibitors (HDACi's), which are being studied in models of a broad range of diseases not related to the proapoptotic properties used to treat cancer. The spectrum of these diseases responsive to HDACi's is for the most part due to several antiinflammatory properties, often observed in vitro but importantly also in animal models. One unifying property is a reduction in cytokine production as well as inhibition of cytokine postreceptor signaling. Distinct from their use in cancer, the reduction in inflammation by HDACi's is consistently observed at low concentrations compared with the higher concentrations required for killing tumor cells. This characteristic makes HDACi's attractive candidates for treating chronic diseases, since low doses are well tolerated. For example, low oral doses of the HDACi givinostat have been used in children to reduce arthritis and are well tolerated. In addition to the antiinflammatory properties, HDACi's have shown promise in models of neurodegenerative disorders, and HDACi's also hold promise to drive HIV-1 out of latently infected cells. No one molecular mechanism accounts for the non-cancer-related properties of HDACi's, since there are 18 genes coding for histone deacetylases. Rather, there are mechanisms unique for the pathological process of specific cell types. In this overview, we summarize the preclinical data on HDACi's for therapy in a wide spectrum of diseases unrelated to the treatment of cancer. The data suggest the use of HDACi's in treating autoimmune as well as chronic inflammatory diseases.

Blocking interleukin-1β in acute and chronic autoinflammatory diseases

An expanding spectrum of acute and chronic inflammatory diseases is considered 'autoinflammatory' diseases. This review considers autoinflammatory diseases as being distinct from 'autoimmune' diseases. Autoimmune diseases are associated with dysfunctional T cells and treated with 'biologicals', including antitumour necrosis factorα, CTLA-Ig, anti-IL-12/23, anti-CD20, anti-IL-17 and anti-IL-6 receptor. In contrast, autoinflammatory diseases are uniquely attributed to a dysfunctional monocyte caspase 1 activity and secretion of IL-1β; indeed, blocking IL-1β results in a rapid and sustained reduction in the severity of most autoinflammatory diseases. Flares of gout, type 2 diabetes, heart failure and smouldering multiple myeloma are examples of seemingly unrelated diseases, which are uniquely responsive to IL 1β neutralization.

Why not treat human cancer with interleukin-1 blockade?

The clinical successes of targeting angiogenesis provide a basis for trials of interleukin-1 (IL-1) blockade and particularly anti-IL-1beta as an add-on therapy in human metastatic disease. In animal studies for over 20 years, IL-1 has been demonstrated to increase adherence of tumor cells to the endothelium in vitro, and administration of IL-1 to mice increases the number of metastatic colonies and tumor growth. Importantly, reducing endogenous IL-1 activity, particularly IL-1beta, with the naturally occurring IL-1 receptor antagonist (IL-1Ra) reduces both metastasis as well as tumor burden. Inhibition of IL-1 activity prevents in vivo blood vessel formation induced by products released from hypoxic macrophages or vascular endothelial cell growth factor itself. Mice deficient in IL-1beta do not form blood vessels in matrigels embedded with vascular endothelial cell growth factor or containing products of macrophages. Recombinant IL-1Ra (anakinra) has been administered to over 1,000 patients with septic shock resulting in a consistent reduction in all-cause 28-day mortality. Approved for treatment of rheumatoid arthritis, anakinra has a remarkable safety record. Anakinra resulted in decreased blood vessels in the pannus of affected joints in patients with rheumatoid arthritis. Neutralizing monoclonal antibodies to IL-1beta and a soluble receptor to IL-1 are approved for treating chronic inflammatory diseases. Given the availability of three therapeutic agents for limiting IL-1 activity, the safety of blocking IL-1, and the clear benefit of blocking IL-1 activity in animal models of metastasis and angiogenesis, clinical trials of IL-1 blockade should be initiated, particularly as an add-on therapy of patients receiving antiangiogenesis-based therapies.

Tumor cell-specific bioluminescence platform to identify stroma-induced changes to anticancer drug activity

Conventional anticancer drug screening is typically performed in the absence of accessory cells of the tumor microenvironment, which can profoundly alter antitumor drug activity. To address this limitation, we developed the tumor cell-specific in vitro bioluminescence imaging (CS-BLI) assay. Tumor cells (for example, myeloma, leukemia and solid tumors) stably expressing luciferase are cultured with nonmalignant accessory cells (for example, stromal cells) for selective quantification of tumor cell viability, in presence versus absence of stromal cells or drug treatment. CS-BLI is high-throughput scalable and identifies stroma-induced chemoresistance in diverse malignancies, including imatinib resistance in leukemic cells. A stroma-induced signature in tumor cells correlates with adverse clinical prognosis and includes signatures for activated Akt, Ras, NF-kappaB, HIF-1alpha, myc, hTERT and IRF4; for biological aggressiveness; and for self-renewal. Unlike conventional screening, CS-BLI can also identify agents with increased activity against tumor cells interacting with stroma. One such compound, reversine, shows more potent activity in an orthotopic model of diffuse myeloma bone lesions than in conventional subcutaneous xenografts. Use of CS-BLI, therefore, enables refined screening of candidate anticancer agents to enrich preclinical pipelines with potential therapeutics that overcome stroma-mediated drug resistance and can act in a synthetic lethal manner in the context of tumor-stroma interactions.

Thrombopoietic cytokine and P-selectin levels in patients with multiple myeloma undergoing autologous stem cell transplantation: decrease in posttransplantation P-selectin levels might predict the degree of maximum response

PURPOSE

This study was designed to determine the pretransplantation levels of thrombopoietic cytokines, which have a fundamental role in both megakaryopoiesis and myeloma pathogenesis and P-selectin in patients with multiple myeloma undergoing autologous hematopoietic stem cell transplantation (AHSCT) and to correlate the cytokine levels with time to platelet recovery. The effect of AHSCT on the levels of the cytokines and its correlation with maximum disease response was also investigated.

PATIENTS AND METHODS

The levels of thrombopoietin, interleukin (IL)-6, IL-11, IL-1beta, and P-selectin was measured before and 30 days after AHSCT in 32 patients with a median age of 55 years. The median time to platelet recovery was day +11 (range, 0-14 days) without any significant correlation with pretransplantation cytokine levels.

RESULTS

No significant change was observed in thrombopoietic cytokines after AHSCT, whereas serum P-selectin levels showed a significant decrease after AHSCT (P = .001). The decrease in P-selectin was found to be significant in patients who achieved complete remission (P1 = .008) and partial remission (P2 = .018) early after AHSCT. Our data suggest that the level of thrombopoietic cytokines does not have a role in time to platelet recovery.

CONCLUSION

The change in P-selectin levels early after transplantation could be a surrogate marker in determining the maximum posttransplantation response.

Induction of a chronic disease state in patients with smoldering or indolent multiple myeloma by targeting interleukin 1{beta}-induced interleukin 6 production and the myeloma proliferative component

OBJECTIVE

To conduct in vitro studies as well as a phase 2 clinical trial in patients with smoldering or indolent multiple myeloma to determine if interleukin 1 (IL-1) inhibitors can delay or prevent active myeloma.

PATIENTS AND METHODS

Stromal cells were cocultured with IL-1beta-expressing myeloma cells in the presence of dexamethasone, IL-1 receptor antagonist (IL-1Ra), or both. Levels of interleukin 6 (IL-6) and of apoptosis were also quantified. Between November 19, 2002, and May 24, 2007, 47 patients were enrolled in the study and subsequently treated with IL-1Ra. In 25 (53%) of the 47 study patients, low-dose dexamethasone (20 mg/wk) was added. The primary end point was progression-free survival (PFS).

RESULTS

In vitro, IL-1Ra was superior to dexamethasone at inhibiting IL-6 production; maximal IL-6 inhibition and apoptosis induction were achieved by addition of both IL-1Ra and dexamethasone. In the clinical trial, 3 patients achieved a minor response to IL-1Ra alone; 5 patients achieved a partial response and 4 patients a minor response after addition of dexamethasone. Seven patients showed a decrease in the plasma cell labeling index that paralleled a decrease in high-sensitivity C-reactive protein (hs-CRP) levels. The median overall PFS was 37.5 months. The median PFS for patients without (n=12) or with (n=35) a greater than 15% decrease in 6-month vs baseline hs-CRP levels was 6 months and more than 3 years, respectively (P=.002). Disease stability was maintained in 8 patients who received therapy for more than 4 years.

CONCLUSION

In patients with smoldering or indolent multiple myeloma who were at risk of progression to active myeloma, treatment with IL-1 inhibitors decreased the myeloma proliferative rate and hs-CRP levels in those who responded, leading to a chronic disease state and an improved PFS.

TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT00635154.

The malignant clone and the bone-marrow environment

Multiple myeloma (MM) is characterized by the clonal expansion of monoclonal immunoglobulin-secreting plasma cells within the bone marrow (BM). It has become clear that the intimate reciprocal relationship between the tumor cell clone and the niches of the BM microenvironment plays a pivotal pathophysiologic role in MM. We and others have identified several new molecular targets and derived novel therapies which induce cytotoxicity against MM cells in the BM milieu, including thalidomide, bortezomib, and lenalidomide. Importantly, these agents induce tumor-cell death, as well as inhibit MM-cell-BM-stromal-cell (BMSC) adhesion and related tumor-cell growth, survival, and migration. Moreover, they block both constitutive and MM-cell binding-induced growth factor and cytokine secretion in BMSCs. Further, they also block tumor angiogenesis and can augment anti-MM immunity. Although all three of these agents are now FDA-approved to treat MM, patients inevitably relapse, and further improvements remain urgently needed. Here we review our current knowledge of the MM cell clone, as well as the impact of the BM microenvironment on tumor-cell growth, survival, migration and drug resistance. Delineating the mechanisms and sequelae of the reciprocal relationship between the MM cell clone, distinct BM extracellular matrix proteins, and accessory cell compartments may provide the basis for new effective therapeutic strategies to re-establish BM homeostasis and thereby improve MM patient outcome.

Preclinical studies of novel targeted therapies

The bone marrow (BM) milieu confers drug resistance in multiple myeloma (MM) cells to conventional therapies. Novel biologically based therapies are therefore needed. Preclinical studies have identified and validated molecular targeted therapeutics in MM. In particular, recognition of the biologic significance of the BM microenvironment in MM pathogenesis and as a potential target for novel therapeutics has already derived several promising approaches. Thalidomide, lenalidomide (Revlimid), and bortezomib (Velcade) are directed not only at MM cells but also at the BM milieu and have moved rapidly from the bench to the bedside and United States Food and Drug Administration approval to treat MM.

Complications of multiple myeloma

Multiple myeloma, also known as myeloma or plasma cell myeloma, is a progressive hematologic disease. Complications of multiple myeloma include renal insufficiency, hematologic complications (anemia, bone marrow failure, bleeding disorders), infections, bone complications (pathologic fractures, spinal cord compression, hyercalcemia), and neurologic complications (spinal cord and nerve root compression, intracranial plasmacytomas, leptomeningeal involvement, among others). This article reviews these various complications connected to multiple myeloma, examining their various causes and possible treatment.

Mayo clinic consensus statement for the use of bisphosphonates in multiple myeloma

Bisphosphonates are effective in the prevention and treatment of bone disease in multiple myeloma (MM). Osteonecrosis of the jaw is Increasingly recognized as a serious complication of long-term bisphosphonate therapy. Issues such as the choice of bisphosphonate and duration of therapy have become the subject of intense debate given patient safety concerns. We reviewed available data concerning the use of bisphosphonates in MM. Guidelines for the use of bisphosphonates in MM were developed by a multidisciplinary panel consisting of hematologists, dental specialists, and nurses specializing in the treatment of MM. We conclude that intravenous pamidronate and intravenous zoledronic acid are equally effective and superior to placebo in reducing skeletal complications. Pamidronate is favored over zoledronic acid until more data are available on the risk of complications (osteonecrosis of the jaw). We recommend discontinuing bisphosphonates after 2 years of therapy for patients who achieve complete response and/or plateau phase. For patients whose disease is active, who have not achieved a response, or who have threatening bone disease beyond 2 years, therapy can be decreased to every 3 months. These guidelines were developed in the Interest of patient safety and will be reexamined as new data emerge regarding risks and benefits.

Targeting signalling pathways for the treatment of multiple myeloma

Multiple myeloma (MM) is characterised by the expansion of monoclonal immunoglobulin-secreting plasma cells. Despite recent advances in systemic and supportive therapy, it remains incurable, with a median survival of about three years. Development of MM is a multistep process associated with an increasing frequency of chromosomal abnormalities and complex translocations, which induce mutations in several proto-oncogenes and tumour suppressor genes. Furthermore, differentiation, maintenance, expansion and drug resistance of MM cells are dependent on multiple growth factors, cytokines, and chemokines, secreted by tumour cells, bone marrow stromal cells, and non-haematopoietic organs; as well as on direct tumour cell-stromal cell contact. Therefore, signalling pathways initiated by both mutated genes in MM cells as well as signals originating in the bone marrow microenvironment represent potential targets for intervention. Close collaboration between basic researchers and clinicians will be required to further improve our knowledge of MM pathophysiologically in order to translate advances from the bench to the bedside and improve patient outcome.

Evidence-based recommendations for monitoring bone disease and the response to enzyme replacement therapy in Gaucher patients

BACKGROUND

Bone disease is a serious complication of Gaucher disease. Untreated, it can result in pain, permanent bone damage and disability. Enzyme replacement therapy reverses many of the clinical signs of Gaucher bone disease but early assessment and treatment, and regular monitoring, are essential in optimising outcomes.

SCOPE

In September 2005, a group of European experts met to review current knowledge and identify best practice and unmet needs in the monitoring of Gaucher bone disease and the response to enzyme replacement therapy.

METHODS

Medline searches of peer-reviewed literature (no date restrictions) were conducted and supplemented by additional information considered relevant by panellists to furthering discussions.

FINDINGS AND CONCLUSIONS

The group's recommendations included: currently used biochemical bone markers are not clinically practical or reliable; plain X-rays should not be the sole method of assessing bone disease; MRI is the most sensitive method for monitoring bone marrow infiltration by Gaucher cells; semi-quantitative methods for assessing bone marrow infiltration in routine clinical practice should use readily available technology, include an assessment of Gaucher cell infiltration in the lumbar spine and femur, and be validated for inter-rater reliability and in comparison to other methods; a multidisciplinary approach is required for the treatment of Gaucher patients; all Gaucher patients should receive a comprehensive initial radiologic evaluation for bone disease and ongoing radiological monitoring at least once every 2 years.

Genomic instability and tissue expression of angiogenic growth factors in sporadic colorectal cancer

BACKGROUND

Chromosomal instability evidenced by a loss of heterozygosity (LOH) is implicated as a predictor of poor survival in patients with colorectal cancer, whereas microsatellite instability (MSI) is associated with improved survival rates. We investigated the relationship between tumor expression of angiogenic growth factors and genomic alterations in colorectal cancer.

METHODS

Two genotypes, LOH and MSI, determined by microsatellite markers in the 4 cancer-related chromosomes 2p, 3p, 17p, and 18q, were analyzed in 73 patients with colorectal cancer. The tumor-specific expression of vascular endothelial growth factor and hepatocyte growth factor (HGF) were quantified, and the interleukin-6 network also was evaluated.

RESULTS

MSI-positive neoplasms showed a lesser expression of both tumor growth factors and interleukin-6. In contrast, LOH-positive neoplasms showed a greater expression of HGF and a lesser expression of interleukin-1-receptor antagonist. MSI neoplasms were correlated with favorable prognosis in agreement with previous findings.

CONCLUSIONS

The suppressed production of angiogenic growth factors in MSI cancers partly might explain the better prognosis in MSI-positive patients. The interleukin-6 network, which upregulates production of vascular endothelial growth factor and HGF, might be involved in this mechanism.

Identification of Two Groups of Smoldering Multiple Myeloma Patients Who Are Either High or Low Producers of Interleukin-1

Interleukin-1beta (IL-1beta) is abnormally expressed by the plasma cells obtained from myeloma patients, and it is a potent inducer of the important myeloma growth factor, IL-6. We investigated whether levels of IL-1beta biologic activity might distinguish different groups of patients with smoldering multiple myeloma (SMM). We measured the ability of IL-6 production by bone marrow stromal cells to serve as a surrogate marker for IL-1beta biologic activity. Using this IL-1beta bioassay, we found that it is sensitive at < 1 pg/ml of recombinant IL-1beta and that IL-1beta biologic activity is detectable with either mature or pro-IL-1beta-transduced myeloma cell lines. Patients with active myeloma induced quantitatively higher levels of stromal cell IL-6 production when compared with those with monoclonal gammopathy of undetermined significance (MGUS). The bioassay distinguished two groups of SMM patients, those who were high producers, similar to patients with active MM, and those who were low producers, comparable to MGUS patients. IL-1 antagonists inhibited the paracrine IL-6 production by > or = 90% in the majority of patients with an elevated IL-6 level. Based on such studies, it may be possible to predict patients that will progress to active MM and to delay or prevent this progression with IL-1 antagonists.

Serum proinflammatory mediators at different periods of therapy in patients with multiple myeloma

Multiple myeloma (MM) is a malignant disease characterized by the clonal proliferation of plasma cells within the bone marrow. Several cytokines have been demonstrated to be involved in the control of growth, progression, and dissemination of MM. We determined serum levels of interleukin-1β (IL-1β), soluble interleukin-2 receptor (sIL-2R), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) in 14 newly diagnosed MM patients. The median age of the patients was 63.4 ± 10.8 years and all of the patients were stage III (classified according to the Durie-Salmon classification). The same parameters were measured in 15 healthy controls. In addition, we also examined the effects of vincristine-adriamycin-dexamethasone (VAD) therapy on the same parameters and mediators as well as the relationship among the parameters in the same patient groups. The serum concentrations of TNF-α, IL-1β, sIL-2R, IL-6, IL-8, and CRP (18.6 ± 3.7 pg/mL, 10.1 ± 2.8 pg/mL, 730 ± 220 U/mL, 11.4 ± 3.3 pg/mL, 23.9 ± 8.3 pg/mL, and 49.9 ± 19.5 mg/dL, resp) were significantly higher in newly diagnosed MM patients than in healthy controls (P < .0001). All of the parameters were found to be significantly reduced after chemotherapy. In conclusion, we found that after the VAD therapy, the level of these cytokines which are thought to play an important role in the pathogenesis of MM was significantly suppressed. This is the first study demonstrating strong impact of VAD treatment on circulating mediators of sIL-2R and IL-8 levels parameters.

Inhibitors of histone deacetylases as anti-inflammatory drugs

This review addresses the issue of histone deacetylase (HDAC) inhibitors as developed for the treatment of cancer and for the investigation of the inhibition of inflammation. The review focuses on both in vitro and in vivo models of inflammation and autoimmunity. Of particular interest is the inhibition of pro-inflammatory cytokines. Although the reduction in cytokines appears paradoxical at first, upon examination, some genes that are anti-inflammatory are upregulated by inhibition of HDAC. Whether skin diseases will be affected by inhibitors of HDAC remains to be tested.

Monoclonal Gammopathy of Undetermined Significance

Monoclonal gammopathy of undetermined significance (MGUS) is characterized by the presence of a monoclonal protein (M-protein) without evidence of multiple myeloma (MM), Waldenstrom's macroglobulinemia (WM), amyloidosis (AL), or a related plasma cell proliferative disorder. Agarose gel electrophoresis followed by immunofixation is recommended for recognition of an M-protein. Monoclonal gammopathy of undetermined significance is found in approximately 3% of persons > 70 years of age and in about 1% of those > 50 years old. In a series of 1384 patients from Southeastern Minnesota in whom MGUS was diagnosed at Mayo Clinic from 1960 through 1994, the risk of progression was 1% per year. This risk of progression continued even after > or = 25 years of a stable M-protein. The risk for developing MM, WM, or AL was increased 25-fold, 46-fold, and 8.4-fold, respectively. The concentration of the serum M-protein, abnormal serum free light-chain ratio, and the presence an immunoglobulin (Ig)M or an IgA M-protein were risk factors for progression. The presence of a urine M-protein or the reduction of > or = 1 uninvolved immunoglobulins was not a risk factor for disease progression. Patients must be monitored for progressive disease throughout their lives. Variants of MGUS consist of IgM MGUS, biclonal gammopathies, triclonal gammopathies, idiopathic Bence Jones (light-chain) proteinuria, and IgD MGUS. Monoclonal gammopathy of undetermined significance may be associated with many disorders, including lymphoproliferative diseases, leukemia, von Willebrand's disease, connective tissue diseases, and neurologic disorders. Epidemiologic and statistical methods must be used to evaluate these associations.

MIP-1 alpha and myeloma bone disease

Figure 5 is a proposed model for MIP-1alpha's effects on myeloma bone disease. MIP-1alpha is produced by myeloma cells and directly stimulates OCL formation. In addition MIP-1alpha enhances adhesive interactions between myeloma cells and marrow stromal cells increasing expression of RANKL and IL-6, which further increase bone destruction and tumor burden. The recent evidence from our group and others lead to the conclusion that MIP-1alpha is an important mediator in the debilitating bone destruction in multiple myeloma. Blocking MIP-1alpha expression may have profound effects on myeloma cell growth, homing, and bone destruction in this in vivo model of myeloma. These data suggest that antagonists that decrease MIP-1alpha activity in vivo or blocking MIP-1alpha signaling by neutralizing its receptor may provide therapeutic alternatives for treating patients with myeloma to decrease both their tumor burden and bone destruction.