Interleukin-32α promotes the proliferation of multiple myeloma cells by inducing production of IL-6 in bone marrow stromal cells

IL-32/NFκB/miR-205 loop sustains the high expression of IL-32 and enhances the motility of cervical cancer cells

Human papillomavirus (HPV) infection is a major contributor to cervical cancer. Persistent HPV infection can trigger the expression of IL-32, yet the precise role of IL-32 in the occurrence and development of cervical cancer remains elusive. To investigate this, qRT‒PCR and western blotting were utilized to measure the mRNA and protein expression levels; bioinformatics analysis was used to screen differentially expressed miRNAs; wound healing and transwell assays were conducted to evaluate cell migration and invasion capabilities. Comparative analysis revealed significantly elevated IL-32 expression in cervical cancer tissues and cell lines compared to control groups. In SiHa and/or HeLa, overexpression of IL-32 and IL-32 exposure markedly upregulated miR-205, whereas its knockdown resulted in a substantial downregulation of miR-205. Furthermore, miR-205 also could significantly regulate the expression of IL-32 in HeLa and SiHa cells. Upregulation and downregulation of IL-32 led to a significant increase or decrease in NFκB expression, respectively. Treatment with BAY11-7082 (an NFκB inhibitor) notably decreased miR-205 expression but had no effect on IL-32 levels. qRT‒PCR and western blotting analyses demonstrated that both overexpression and underexpression of IL-32 and miR-205 significantly enhanced or reduced MMP2 and MMP9 expression in cervical cancer cells, respectively. Knockdown of IL-32 significantly inhibited the migration and invasion of HeLa and SiHa; conversely, treatment with rIL-32α and rIL-32γ notably promoted their migration and invasion. In brief, IL-32 is highly expressed via the formation of a positive regulatory loop with NFκB/miR-205, contributing to the persistence of inflammation and promoting the progression of cervical cancer.

Role of interleukin‑32 in cancer progression (Review)

Interleukin (IL)-32 is induced by pro-inflammatory cytokines and promotes the release of inflammatory cytokines. Therefore, it can promote inflammatory responses. The present review article summarized the role of the receptors required for IL-32 action, the biological function of IL-32 and its mechanism of action in tumors. Moreover, it assessed the significance of aberrant IL-32 expression in associated diseases and analyzed the effects of IL-32 on four key types of cancer: Colorectal, gastric, breast and lung. However, the mechanism of action of IL-32 needs to be further demonstrated by assessing the role of this cytokine in cancer to elucidate novel and reliable targets for future cancer treatments.

The pro-tumorigenic cytokine IL-32 has a high turnover in multiple myeloma cells due to proteolysis regulated by oxygen-sensing cysteine dioxygenase and deubiquitinating enzymes

IL-32 is a pro-inflammatory cytokine expressed by several types of cancer cells and immune cells. Currently, no treatment targeting IL-32 is available, and its intracellular and exosomal localization make IL-32 less accessible to drugs. We previously showed that hypoxia promotes IL-32 expression through HIF1α in multiple myeloma cells. Here, we demonstrate that high-speed translation and ubiquitin-dependent proteasomal degradation lead to a rapid IL-32 protein turnover. We find that IL-32 protein half-life is regulated by the oxygen-sensing cysteine-dioxygenase ADO and that deubiquitinases actively remove ubiquitin from IL-32 and promote protein stability. Deubiquitinase inhibitors promoted the degradation of IL-32 and may represent a strategy for reducing IL-32 levels in multiple myeloma. The fast turnover and enzymatic deubiquitination of IL-32 are conserved in primary human T cells; thus, deubiquitinase inhibitors may also affect T-cell responses in various diseases.

Human IL-32θA94V mutant attenuates monocyte-endothelial adhesion by suppressing the expression of ICAM-1 and VCAM-1 via binding to cell surface receptor integrin αVβ3 and αVβ6 in TNF-α-stimulated HUVECs

Interleukin-32 (IL-32), first reported in 2005, and its isoforms have been the subject of numerous studies investigating their functions in virus infection, cancer, and inflammation. IL-32θ, one of the IL-32 isoforms, has been shown to modulate cancer development and inflammatory responses. A recent study identified an IL-32θ mutant with a cytosine to thymine replacement at position 281 in breast cancer tissues. It means that alanine was also replaced to valine at position 94 in amino acid sequence (A94V). In this study, we investigated the cell surface receptors of IL-32θA94V and evaluated their effect on human umbilical vein endothelial cells (HUVECs). Recombinant human IL-32θA94V was expressed, isolated, and purified using Ni-NTA and IL-32 mAb (KU32-52)-coupled agarose columns. We observed that IL-32θA94V could bind to the integrins αVβ3 and αVβ6, suggesting that integrins act as cell surface receptors for IL-32θA94V. IL-32θA94V significantly attenuated monocyte-endothelial adhesion by inhibiting the expression of Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in tumor necrosis factor (TNF)-α-stimulated HUVECs. IL-32θA94V also reduced the TNF-α-induced phosphorylation of protein kinase B (AKT) and c-jun N-terminal kinases (JNK) by inhibiting phosphorylation of focal adhesion kinase (FAK). Additionally, IL-32θA94V regulated the nuclear translocation of nuclear factor kappa B (NF-κB) and activator protein 1 (AP-1), which are involved in ICAM-1 and VCAM-1 expression. Monocyte-endothelial adhesion mediated by ICAM-1 and VCAM-1 is an important early step in atherosclerosis, which is a major cause of cardiovascular disease. Our findings suggest that IL-32θA94V binds to the cell surface receptors, integrins αVβ3 and αVβ6, and attenuates monocyte-endothelial adhesion by suppressing the expression of ICAM-1 and VCAM-1 in TNF-α-stimulated HUVECs. These results demonstrate that IL-32θA94V can act as an anti-inflammatory cytokine in a chronic inflammatory disease such as atherosclerosis.

Interleukin-32γ promotes macrophage-mediated chemoresistance by inducing CSF1-dependent M2 macrophage polarization in multiple myeloma

Macrophages (MΦs) are an abundant component in the multiple myeloma (MM) environment and contribute to MM drug resistance. We previously showed that interleukin-32 (IL-32) is highly expressed in MM patients and induces the immunosuppressive function of MΦs. The present study was designed to explore the role of IL-32 in MΦ-mediated MM drug resistance and the underlying mechanism. Our analysis revealed that IL-32 expression was upregulated in relapsed MM patients and associated with CD206⁺ M2 MΦ infiltration. Subsequently, we found that the most active isoform, IL-32γ, promoted MΦs to protect MM cells from drug-induced apoptosis both in vitro and in vivo. Furthermore, by evaluating many parameters, including surface markers, cytokines, metabolic enzymes and characteristic molecules, IL-32γ was verified to induce the polarization of M2 MΦs, a function that was partly dependent on increasing the expression of colony-stimulating factor 1 (CSF1). Taken together, the results of our study indicate that IL-32γ promotes MΦ-mediated MM drug resistance and modifies MΦs toward the M2 phenotype, providing a crucial theoretical basis for targeted MΦ immunotherapy.

Diverse and divergent functions of IL-32β and IL-32γ isoforms in the regulation of malignant pleural mesothelioma cell growth and the production of VEGF-A and CXCL8

In this study, we sought to elucidate the roles of the interleukin (IL)-32β and IL-32γ in mesothelioma cell growth, and vascular endothelial growth factor (VEGF)-A and C-X-C motif chemokine ligand 8 (CXCL8) expression. IL-32 elicited a growth-promoting effect against one of the six mesotheliomas lines and exerted diverse regulatory functions in VEGF-A and CXCL8 secretion from mesotheliomas stimulated with or without IL-17A. Retroviral-mediated transduction of mesothelioma lines with IL-32γ resulted in enhanced IL-32β expression, which facilitated or suppressed the in vitro growth, and VEGF-A and CXCL8 expression. Overexpressed IL-32β-augmented growth and VEGF-A and CXCL8 production were mainly mediated through the phosphatidylinositol-3 kinase (PI3K) signaling pathway. On the other hand, overexpressed IL-32β-deceased growth was mediated through mitogen-activated protein kinase (MAPK) pathway. NCI-H2373IL-32γ tumors grew faster than NCI-H2373Neo tumors in a xenograft model, which was associated with increased vascularity. These findings indicate that IL-32 are involved in the regulation of growth and angiogenic factor production in mesotheliomas.

IL-32 is induced by activation of toll-like receptors in multiple myeloma cells

Multiple myeloma (MM) is a hematological cancer characterized by accumulation of malignant plasma cells in the bone marrow. The patients are immune suppressed and suffer from recurrent and chronic infections. Interleukin-32 is a non-conventional, pro-inflammatory cytokine expressed in a subgroup of MM patients with a poor prognosis. IL-32 has also been shown to promote proliferation and survival of the cancer cells. Here we show that activation of toll-like receptors (TLRs) promotes expression of IL-32 in MM cells through NFκB activation. In patient-derived primary MM cells, IL-32 expression is positively associated with expression of TLRs. Furthermore, we found that several TLR genes are upregulated from diagnosis to relapse in individual patients, predominantly TLRs sensing bacterial components. Interestingly, upregulation of these TLRs coincides with an increase in IL-32. Taken together, these results support a role for IL-32 in microbial sensing in MM cells and suggest that infections can induce expression of this pro-tumorigenic cytokine in MM patients.

Impact of interleukin-32α on T helper cell-related cytokines, transcription factors, and proliferation in patients with type 2 diabetes mellitus

OBJECTIVE

The ability of interleukin (IL)-32α to induce T helper (Th) 1, Th17, and Treg cytokines (IFN-γ, IL-17, and IL-10, respectively), and transcription factors [(signal transducer and activator of transcription (STAT) 1 and T-box (T-bet) for Th1, STAT3 and retinoid-related orphan receptor (ROR)-γt for Th17, and STAT5 and forkhead box P3 (Foxp3) for Treg)] were investigated in type 2 diabetes mellitus (T2DM). IL-32α effects on Th cell proliferation and related factors including IL-2 and NF-κB were also explored.

METHODS

Serum levels of IL-32α in 31 patients and 31 healthy controls (HCs) were determined by ELISA assay. CD4⁺ T cells cultured with polyclonal activators in the presence and absence of recombinant IL-32α (rIL-32α). Gene expressions in cultured Th cells were assessed with real-time PCR. Cytokines in supernatants were measured with ELISA. Proliferation experiments were assessed by flow cytometry.

RESULTS

The patients showed significant increase in IL-32α levels compared with HCs and its levels were positively correlated with fasting plasma glucose and hemoglobin A1c. rIL-32α enhanced IL-17 and IL-2 production, increased ROR-γt and NF-κB expression, and enhanced Th proliferation in both patients and HCs. In patients, IL-17, ROR-γt, NF-κB, and proliferation levels were higher than those in HCs, in cultures with and without rIL-32α (rIL-32α⁺ and rIL-32α^-). IL-2 levels in rIL-32α⁺cultures of patients were significantly higher than the HCs, and it was positively correlated with proliferation rate and NF-κB expression.

CONCLUSIONS

Aberrant IL-32α levels are participated in T2DM pathogenesis. IL-32α potently induces Th17-related factors and amplifies the proliferative function of T cells.

A Paradoxical Effect of Interleukin-32 Isoforms on Cancer

IL-32 plays a contradictory role such as tumor proliferation or suppressor in cancer development depending on the cancer type. In most cancers, it was found that the high expression of IL-32 was associated with more proliferative and progression of cancer. However, studying the isoforms of IL-32 cytokine has placed its paradoxical role into a wide range of functions based on its dominant isoform and surrounding environment. IL-32β, for example, was found mostly in different types of cancer and associated with cancer expansion. This observation is legitimate since cancer exhibits some hypoxic environment and IL-32β was known to be induced under hypoxic conditions. However, IL-32θ interacts directly with protein kinase C-δ reducing NF-κB and STAT3 levels to inhibit epithelial-mesenchymal transition (EMT). This effect could explain the different functions of IL-32 isoforms in cancer. However, pro- or antitumor activity which is dependant on obesity, gender, and age as it relates to IL-32 has yet to be studied. Obesity-related IL-32 regulation indicated the role of IL-32 in cancer metabolism and inflammation. IL-32-specific direction in cancer therapy is difficult to conclude. In this review, we address that the paradoxical effect of IL-32 on cancer is attributed to the dominant isoform, cancer type, tumor microenvironment, and genetic background. IL-32 seems to have a contradictory role in cancer. However, investigating multiple IL-32 isoforms could explain this doubt and bring us closer to using them in therapy.

Interleukin-32 in Pathogenesis of Atopic Diseases: Proinflammatory or Anti-Inflammatory Role?

Atopic diseases, such as atopic dermatitis (AD), allergic asthma (AA), and allergic rhinitis (AR), are increasingly becoming a worldwide issue. This atopic triad originates at an early age and on a multifactorial basis, causing significant discomfort to susceptible individuals. The global case number is now reaching new highs, so exploring immune system regulation and its components is becoming critical. One cytokine, interleukin-32 (IL-32), is involved in inflammation and regulation of the immune system. It has nine isoforms that show varying degrees of expression, both intracellularly and extracellularly. IL-32 is secreted by immune cells, such as monocytes, macrophages, natural killer cells, and T cells, and by nonimmune cells, including fibroblasts, keratinocytes, and endothelial cells. Its production is regulated and augmented by microorganisms, mitogens, and other cytokines. Early studies demonstrated that IL-32 was an immune regulator that functioned to protect against inflammatory diseases, including AD, AA, and AR, and proposed a proinflammatory role for IL-32 in immune regulation and symptom exacerbation. However, several later reports suggested that IL-32 is downregulated in inflammatory diseases and exerts an anti-inflammatory effect. This review article focuses on recent findings regarding the detrimental and protective roles of IL-32 in development and management of inflammatory diseases. The exact role of IL-32 in AD, AA, and AR still remains to be elucidated. Future research should explore new avenues of IL-32 functionality in human inflammatory diseases.

Genetic program activity delineates risk, relapse, and therapy responsiveness in multiple myeloma

Despite recent advancements in the treatment of multiple myeloma (MM), nearly all patients ultimately relapse and many become refractory to multiple lines of therapies. Therefore, we not only need the ability to predict which patients are at high risk for disease progression but also a means to understand the mechanisms underlying their risk. Here, we report a transcriptional regulatory network (TRN) for MM inferred from cross-sectional multi-omics data from 881 patients that predicts how 124 chromosomal abnormalities and somatic mutations causally perturb 392 transcription regulators of 8549 genes to manifest in distinct clinical phenotypes and outcomes. We identified 141 genetic programs whose activity profiles stratify patients into 25 distinct transcriptional states and proved to be more predictive of outcomes than did mutations. The coherence of these programs and accuracy of our network-based risk prediction was validated in two independent datasets. We observed subtype-specific vulnerabilities to interventions with existing drugs and revealed plausible mechanisms for relapse, including the establishment of an immunosuppressive microenvironment. Investigation of the t(4;14) clinical subtype using the TRN revealed that 16% of these patients exhibit an extreme-risk combination of genetic programs (median progression-free survival of 5 months) that create a distinct phenotype with targetable genes and pathways.

Immunological Prognostic Factors in Multiple Myeloma

Multiple myeloma (MM) is a plasma cell neoplasm characterized by an abnormal proliferation of clonal, terminally differentiated B lymphocytes. Current approaches for the treatment of MM focus on developing new diagnostic techniques; however, the search for prognostic markers is also crucial. This enables the classification of patients into risk groups and, thus, the selection of the most optimal treatment method. Particular attention should be paid to the possible use of immune factors, as the immune system plays a key role in the formation and course of MM. In this review, we focus on characterizing the components of the immune system that are of prognostic value in MM patients, in order to facilitate the development of new diagnostic and therapeutic directions.

Myeloma-Modified Adipocytes Exhibit Metabolic Dysfunction and a Senescence-Associated Secretory Phenotype

Bone marrow adipocytes (BMAd) have recently been implicated in accelerating bone metastatic cancers, such as acute myelogenous leukemia and breast cancer. Importantly, bone marrow adipose tissue (BMAT) expands with aging and obesity, two key risk factors in multiple myeloma disease prevalence, suggesting that BMAds may influence and be influenced by myeloma cells in the marrow. Here, we provide evidence that reciprocal interactions and cross-regulation of myeloma cells and BMAds play a role in multiple myeloma pathogenesis and treatment response. Bone marrow biopsies from patients with multiple myeloma revealed significant loss of BMAT with myeloma cell infiltration of the marrow, whereas BMAT was restored after treatment for multiple myeloma. Myeloma cells reduced BMAT in different preclinical murine models of multiple myeloma and in vitro using myeloma cell-adipocyte cocultures. In addition, multiple myeloma cells altered adipocyte gene expression and cytokine secretory profiles, which were also associated with bioenergetic changes and induction of a senescent-like phenotype. In vivo, senescence markers were also increased in the bone marrow of tumor-burdened mice. BMAds, in turn, provided resistance to dexamethasone-induced cell-cycle arrest and apoptosis, illuminating a new possible driver of myeloma cell evolution in a drug-resistant clone. Our findings reveal that bidirectional interactions between BMAds and myeloma cells have significant implications for the pathogenesis and treatment of multiple myeloma. Targeting senescence in the BMAd or other bone marrow cells may represent a novel therapeutic approach for treatment of multiple myeloma. SIGNIFICANCE: This study changes the foundational understanding of how cancer cells hijack the bone marrow microenvironment and demonstrates that tumor cells induce senescence and metabolic changes in adipocytes, potentially driving new therapeutic directions.

Increased levels of interleukin-32 isoforms alpha, beta, gamma, and delta in the gingival crevicular fluid and plasma of the patients with periodontitis

BACKGROUND AND OBJECTIVE

Interleukin (IL)-32, which has been recently reported to be associated with periodontitis, has been suggested to have pleiotropic effect due to its 9 different isoforms. The aim of this study was to investigate the levels of IL-32α, IL-32β, IL-32γ, IL-32δ isoforms in gingival crevicular fluid (GCF) and plasma before and after non-surgical periodontal treatment in patients with periodontitis (P).

MATERIALS AND METHODS

Twenty-seven P and 27 periodontally healthy controls (C) were recruited in this study. Non-surgical periodontal treatment was performed to periodontitis patients. GCF and plasma sampling and clinical periodontal parameters were evaluated before and 1 month after treatment. Enzyme-linked immunosorbent assay was used to analyze the levels of IL-32α, IL-32β, IL-32γ, IL-32δ isoforms in GCF and plasma samples.

RESULTS

The levels of IL-32α, IL-32β, IL-32γ, and IL-32δ in plasma and GCF were significantly higher in patients with periodontitis than healthy controls (P < .001). In P group, plasma and GCF IL-32α, IL-32β, IL-32γ, and IL-32δ levels after non-surgical periodontal treatment were lower when compared to baseline (P < .001). Moreover, there was a positive correlation between GCF and plasma IL-32α, IL-32β, IL-32γ, and IL-32δ levels in all groups at baseline and after treatment (P < .05).

CONCLUSION

The study supported that there was a relationship between elevated levels of IL-32 isoforms and periodontitis. Also, our novel findings suggest that the pro-inflammatory role of IL-32 in the periodontitis may be originated from IL-32α, IL-32β, IL-32γ, and IL-32δ isoforms.

Molecular interactions and functions of IL-32

IL-32 is a multifaceted cytokine associated with several diseases and inflammatory conditions. Its expression is induced in response to cellular stress such as hypoxia, infections, and pro-inflammatory cytokines. IL-32 can be secreted from cells and can induce the production of pro-inflammatory cytokines from several cell types but are also described to have anti-inflammatory functions. The intracellular form of IL-32 is shown to play an important role in various cellular processes, including the defense against intracellular bacteria and viruses and in modulation of cell metabolism. In this review, we discuss current literature on molecular interactions of IL-32 with other proteins. We also review data on the role of intracellular IL-32 as a metabolic regulator and its role in antimicrobial host defense.

Gene Expression in Patient-Derived Neural Progenitors Implicates WNT5A Signaling in the Etiology of Schizophrenia

BACKGROUND

Genome-wide association studies of schizophrenia have demonstrated that variations in noncoding regions are responsible for most of the common variation heritability of the disease. It is hypothesized that these risk variants alter gene expression. Therefore, studying alterations in gene expression in schizophrenia may provide a direct approach to understanding the etiology of the disease. In this study we use cultured neural progenitor cells derived from olfactory neuroepithelium (CNON cells) as a genetically unaltered cellular model to elucidate the neurodevelopmental aspects of schizophrenia.

METHODS

We performed a gene expression study using RNA sequencing of CNON cells from 111 control subjects and 144 individuals with schizophrenia. Differentially expressed genes were identified with DESeq2 software, using covariates to correct for sex, age, library batches, and 1 surrogate variable component.

RESULTS

A total of 80 genes were differentially expressed (false discovery rate < 10%), showing enrichment in cell migration, cell adhesion, developmental process, synapse assembly, cell proliferation, and related Gene Ontology categories. Cadherin and Wnt signaling pathways were positive in overrepresentation test, and, in addition, many genes were specifically involved in WNT5A signaling. The differentially expressed genes were modestly, but significantly, enriched in the genes overlapping single nucleotide polymorphisms with genome-wide significant association from the Psychiatric Genomics Consortium genome-wide association study of schizophrenia. We also found substantial overlap with genes associated with other psychiatric disorders or brain development, enrichment in the same Gene Ontology categories as genes with mutations de novo in schizophrenia, and studies of induced pluripotent stem cell-derived neural progenitor cells.

CONCLUSIONS

CNON cells are a good model of the neurodevelopmental aspects of schizophrenia and can be used to elucidate the etiology of the disorder.

A Comprehensive Biological and Clinical Perspective Can Drive a Patient-Tailored Approach to Multiple Myeloma: Bridging the Gaps between the Plasma Cell and the Neoplastic Niche

There is a broad spectrum of diseases labeled as multiple myeloma (MM). This is due not only to the composite prognostic risk factors leading to different clinical outcomes and responses to treatments but also to the composite tumor microenvironment that is involved in a vicious cycle with the MM plasma cells. New therapeutic strategies have improved MM patients' chances of survival. Nevertheless, certain patients' subgroups have a particularly unfavorable prognosis. Biological stratification can be subdivided into patient, disease, or therapy-related factors. Alternatively, the biological signature of aggressive disease and dismal therapeutic response can promote a dynamic, comprehensive strategic approach, better tailoring the clinical management of high-risk profiles and refractoriness to therapy and taking into account the role played by the MM milieu. By means of an extensive literature search, we have reviewed the state-of-the-art pathophysiological insights obtained from translational investigations of the MM-bone marrow microenvironment. A good knowledge of the MM niche pathophysiological dissection is crucial to tailor personalized approaches in a bench-bedside fashion. The discussion in this review pinpoints two main aspects that appear fundamental in order to gain novel and definitive results from the biology of MM. A systematic knowledge of the plasma cell disorder, along with greater efforts to face the unmet needs present in MM evolution, promises to open a new therapeutic window looking out onto the plethora of scientific evidence about the myeloma and the bystander cells.

Expression of interleukin-32 in bone marrow of patients with myeloma and its prognostic significance

BACKGROUND

The guiding effect of prognostic stratification in multiple myeloma (MM) for treatment has been increasingly emphasized in recent years. The stratification of risk factors based on the International Staging System (ISS), Durie-Salmon (DS) staging and related indicators is affected by the renal function of patients, resulting in poor performance. This study assesses the relationship between interleukin-32 (IL-32) and related risk factors in 67 patients with MM and their clinical outcomes.

AIM

To investigate the feasibility of IL-32 in evaluating prognosis in patients with MM and the factors influencing prognosis.

METHODS

This was a pragmatic, prospective observational study of patients with MM at a single center. According to IL-32 level, patients were divided into two groups. The variables under consideration included age, blood β₂-microglobulin, albumin, C-reactive protein, serum calcium, serum creatinine, lactate dehydrogenase, M protein type, ISS stage, DS stage, and IL-32 levels and minimal residual disease (MRD) after induction treatment. The main outcomes were progression-free survival (PFS) and overall survival (OS).

RESULTS

IL-32 was an important factor affecting PFS and OS in patients with MM. Compared with patients with IL-32 levels ≥ 856.4 pg/mL, patients with IL-32 levels < 856.4 pg/mL had longer PFS (P = 0.0387) and OS (P = 0.0379); Univariate analysis showed that IL-32 level and MRD were significantly associated with OS and PFS (P < 0.05). Multivariate analysis showed that IL-32 levels ≥ 856.4 pg/mL and MRD positive were still independent risk factors for OS and PFS (P < 0.05).

CONCLUSION

IL-32 is valuable for assessing the prognosis of MM patients. IL-32 level combined with MRD may be a useful routine evaluation index for MM patients after treatment.

Interleukin 30 to Interleukin 40

Cytokines are important molecules that regulate the ontogeny and function of the immune system. They are small secreted proteins usually produced upon activation of cells of the immune system, including lymphocytes and myeloid cells. Many cytokines have been described, and several have been recognized as pivotal players in immune responses and in human disease. In fact, several anticytokine antibodies have proven effective therapeutics, especially in various autoimmune diseases. In the last 15 years, new cytokines have been described, and many remain poorly understood. Among the most recent cytokines discovered are interleukins-30 (IL-30) to IL-40. Several of these are members of other cytokine superfamilies, including several IL-1 superfamily members (IL-33, IL-36, IL-37, and IL-38) as well as several new members of the IL-12 family (IL-30, IL-35, and IL-39). The rest (IL-31, IL-32, IL-34, and IL-40) are encoded by genes that do not belong to any cytokine superfamily. Our aim of this review was to present a concise version of the information available on these novel cytokines to facilitate their understanding by members of the immunological community.

Non-lethal proteasome inhibition activates pro-tumorigenic pathways in multiple myeloma cells

Multiple myeloma (MM) is a haematological malignancy being characterized by clonal plasma cell proliferation in the bone marrow. Targeting the proteasome with specific inhibitors (PIs) has been proven a promising therapeutic strategy and PIs have been approved for the treatment of MM and mantle‐cell lymphoma; yet, while outcome has improved, most patients inevitably relapse. As relapse refers to MM cells that survive therapy, we sought to identify the molecular responses induced in MM cells after non‐lethal proteasome inhibition. By using bortezomib (BTZ), epoxomicin (EPOX; a carfilzomib‐like PI) and three PIs, namely Rub999, PR671A and Rub1024 that target each of the three proteasome peptidases, we found that only BTZ and EPOX are toxic in MM cells at low concentrations. Phosphoproteomic profiling after treatment of MM cells with non‐lethal (IC₁₀) doses of the PIs revealed inhibitor‐ and cell type‐specific readouts, being marked by the activation of tumorigenic STAT3 and STAT6. Consistently, cytokine/chemokine profiling revealed the increased secretion of immunosuppressive pro‐tumorigenic cytokines (IL6 and IL8), along with the inhibition of potent T cell chemoattractant chemokines (CXCL10). These findings indicate that MM cells that survive treatment with therapeutic PIs shape a pro‐tumorigenic immunosuppressive cellular and secretory bone marrow microenvironment that enables malignancy to relapse.

Multiple myeloma cell-derived IL-32γ increases the immunosuppressive function of macrophages by promoting indoleamine 2,3-dioxygenase (IDO) expression

The interaction of multiple myeloma (MM) cells with macrophages (MΦs) contributes to the pathophysiology of MM. We previously showed that IL-32 is overexpressed in MM patients. The present study was designed to explore the clinical significance of IL-32 in MM and to further elucidate the mechanisms underlying the IL-32-mediated immune function of MΦs. Our results showed that high IL-32 expression in MM patients was associated with more advanced clinical stage. RNA-sequencing revealed that IL-32γ significantly induced the production of the immunosuppressive molecule indoleamine 2,3-dioxygenase (IDO) in MΦs, and this effect was verified by qRT-PCR, western blotting, and immunofluorescence. Furthermore, MM cells with IL-32-knockdown showed a reduced ability to promote IDO expression. As a binding protein for IL-32, proteinase 3 (PR3) was universally expressed on the surfaces of MΦs, and knockdown of PR3 or inhibition of the STAT3 and NF-κB pathways hindered the IL-32γ-mediated stimulation of IDO expression. Finally, IDO-positive IL-32γ-educated MΦs inhibited CD4⁺ T cell proliferation and IL-2, IFN-γ, and TNF-α production. Taken together, our results indicate that IL-32γ derived from MM cells promotes the immunosuppressive function of MΦs and is a potential target for MM treatment.

Interleukin-32: its role in asthma and potential as a therapeutic agent

Interleukin (IL)-32, also named natural killer cell transcript 4 (NK4), has increasingly been described as an immunoregulator that controls cell differentiation and cell death and is involved in the stimulation of anti−/pro-inflammatory cytokines. Abnormal presence of IL-32 has been repeatedly noticed during the pathogenesis of allergic, infectious, cancerous, and inflammatory diseases. Of particular note was the observation of the anti-inflammatory property of IL-32 in a murine ovalbumin model of allergic asthma. Compared to wild-type mice, IL-32γ transgenic mice show decreased levels of inflammatory cells, recruited eosinophils, and lymphocytes in bronchoalveolar lavage fluid in a mouse model of acute asthma. To date, the molecular mechanism underlying the role of IL-32 in asthma remains to be elucidated. This review aims to summarize recent advances in the pathophysiology of asthma and describe the links to IL-32. The possibilities of using IL-32 as an airway inflammation biomarker and an asthma therapeutic agent are also evaluated.

Role of interleukin-32 in cancer biology

Interleukin-32 (IL-32), a novel proinflammatory cytokine, is highly expressed in various cancer tissues and in established cancer cell lines. IL-32 has been revealed to serve a crucial role in human cancer development, including tumour initiation, proliferation and maintenance. The expression of IL-32 is regulated by numerous factors, including genetic variations, hypoxia and acidosis in the tumour microenvironment. Understanding the underlying mechanisms of IL-32 expression and its function are critical for the discovery of novel therapeutic strategies that target IL-32. This is a review of the current literature on the regulation and function of IL-32 in cancer progression, focusing on the molecular pathways linking IL-32 and tumour development.