Tumor Cell-Associated IL-1α Affects Breast Cancer Progression and Metastasis in Mice through Manipulation of the Tumor Immune Microenvironment.

IL-1α is a dual function cytokine that affects inflammatory and immune responses and plays a pivotal role in cancer. The effects of intracellular IL-1α on the development of triple negative breast cancer (TNBC) in mice were assessed using the CRISPR/Cas9 system to suppress IL-1α expression in 4T1 breast cancer cells. Knockout of IL-1α in 4T1 cells modified expression of multiple genes, including downregulation of cytokines and chemokines involved in the recruitment of tumor-associated pro-inflammatory cells. Orthotopical injection of IL-1α knockout (KO) 4T1 cells into BALB/c mice led to a significant decrease in local tumor growth and lung metastases, compared to injection of wild-type 4T1 (4T1/WT) cells. Neutrophils and myeloid-derived suppressor cells were abundant in tumors developing after injection of 4T1/WT cells, whereas more antigen-presenting cells were observed in the tumor microenvironment after injection of IL-1α KO 4T1 cells. This switch correlated with increased infiltration of CD3+CD8+ and NKp46+cells. Engraftment of IL-1α knockout 4T1 cells into immunodeficient NOD.SCID mice resulted in more rapid tumor growth, with increased lung metastasis in comparison to engraftment of 4T1/WT cells. Our results suggest that tumor-associated IL-1α is involved in TNBC progression in mice by modulating the interplay between immunosuppressive pro-inflammatory cells vs. antigen-presenting and cytotoxic cells.

Salmonella manipulates the host to drive pathogenicity via induction of interleukin 1ß.

Acute gastrointestinal infection with intracellular pathogens like Salmonella Typhimurium triggers the release of the proinflammatory cytokine interleukin 1ß (IL-1ß). However, the role of IL-1ß in intestinal defense against Salmonella remains unclear. Here, we show that IL-1ß production is detrimental during Salmonella infection. Mice lacking IL-1ß (IL-1ß -/-) failed to recruit neutrophils to the gut during infection, which reduced tissue damage and prevented depletion of short-chain fatty acid (SCFA)-producing commensals. Changes in epithelial cell metabolism that typically support pathogen expansion, such as switching energy production from fatty acid oxidation to fermentation, were absent in infected IL-1ß -/- mice which inhibited Salmonella expansion. Additionally, we found that IL-1ß induces expression of complement anaphylatoxins and suppresses the complement-inactivator carboxypeptidase N (CPN1). Disrupting this process via IL-1ß loss prevented mortality in Salmonella-infected IL-1ß -/- mice. Finally, we found that IL-1ß expression correlates with expression of the complement receptor in patients suffering from sepsis, but not uninfected patients and healthy individuals. Thus, Salmonella exploits IL-1ß signaling to outcompete commensal microbes and establish gut colonization. Moreover, our findings identify the intersection of IL-1ß signaling and the complement system as key host factors involved in controlling mortality during invasive Salmonellosis.

Gene deletion of Interleukin-1α reduces ER stress-induced CHOP expression in macrophages and attenuates the progression of atherosclerosis in apoE-deficient mice.

The pathophysiology of atherosclerosis initiation and progression involves many inflammatory cytokines, one of them is interleukin (IL)-1α that has been shown to be secreted by activated macrophages. We have previously shown that IL-1α from bone marrow-derived cells is critical for early atherosclerosis development in mice. It is known that endoplasmic reticulum (ER) stress in macrophages is involved in progression to more advanced atherosclerosis, but it is still unknown whether this effect is mediated through cytokine activation or secretion. We previously demonstrated that IL-1α is required in ER stress-induced activation of inflammatory cytokines in hepatocytes and in the associated induction of steatohepatitis. In the current study, we aimed to examine the potential role of IL-1α in ER stress-induced activation of macrophages, which is relevant to progression of atherosclerosis. First, we demonstrated that IL-1α is required for atherosclerosis development and progression in the apoE knockout (KO) mouse model of atherosclerosis. Next, we showed that ER stress in mouse macrophages results in the protein production and secretion of IL-1α in a dose-dependent manner, and that IL-1α is required in ER stress-induced production of the C/EBP homologous protein (CHOP), a critical step in ER stress-mediated apoptosis. We further demonstrated that IL-1α-dependent CHOP production in macrophages is specifically mediated through the PERK-ATF4 signaling pathway. Altogether, these findings highlight IL-1α as a potential target for prevention and treatment of atherosclerotic cardiovascular disease.

Tryptophol Acetate and Tyrosol Acetate, Small-Molecule Metabolites Identified in a Probiotic Mixture, Inhibit Hyperinflammation.

Probiotic fermented foods are perceived as contributing to human health; however, solid evidence for their presumptive therapeutic systemic benefits is generally lacking. Here we report that tryptophol acetate and tyrosol acetate, small-molecule metabolites secreted by the probiotic milk-fermented yeast Kluyveromyces marxianus, inhibit hyperinflammation (e.g., "cytokine storm"). Comprehensive in vivo and in vitro analyses, employing LPS-induced hyperinflammation models, reveal dramatic effects of the molecules, added in tandem, on mice morbidity, laboratory parameters, and mortality. Specifically, we observed attenuated levels of the proinflammatory cytokines IL-6, IL-1α, IL-1ß, and TNF-α and reduced reactive oxygen species. Importantly, tryptophol acetate and tyrosol acetate did not completely suppress proinflammatory cytokine generation, rather brought their concentrations back to baseline levels, thus maintaining core immune functions, including phagocytosis. The anti-inflammatory effects of tryptophol acetate and tyrosol acetate were mediated through downregulation of TLR4, IL-1R, and TNFR signaling pathways and increased A20 expression, leading to NF-kB inhibition. Overall, this work illuminates phenomenological and molecular details underscoring anti-inflammatory properties of small molecules identified in a probiotic mixture, pointing to potential therapeutic avenues against severe inflammation.

Pathogenetic role and clinical significance of interleukin-1ß in cancer.

In recent years, pro-oncogenic mechanisms of the tumour microenvironment (ТМЕ) have been actively discussed. One of the main cytokines of the TМЕ is interleukin-1 beta (IL-1ß), which exhibits proinflammatory properties. Some studies have shown an association between an increase in IL-1ß levels and tumour progression. The purpose of this review is to analyse the pathogenic mechanisms induced by IL-1ß in the TМЕ, as well as the diagnostic significance of the presence of IL-1ß in patients with cancer and the efficacy of treatment with IL-1ß inhibitors. According to the literature, IL-1ß can induce an increase in tumour angiogenesis due to its effects on the differentiation of epithelial cells, pro-angiogenic molecule secretion and expression of adhesion molecules, thus increasing tumour growth and metastasis. IL-1ß is also involved in the suppression of anti-tumour immune responses. The expression and secretion of IL-1ß has been noted in various types of tumours. In some clinical studies, an elevated level of IL-1ß was found to be associated with low efficacy of anti-cancer therapy and a poor prognosis. In most experimental and clinical studies, the use of IL-1ß inhibitors contributed to a decrease in tumour mass and an increase in the response to anti-tumour drugs.

Subcapsular Sinus Macrophages Promote Melanoma Metastasis to the Sentinel Lymph Nodes via an IL1α-STAT3 Axis.

During melanoma metastasis, tumor cells originating in the skin migrate via lymphatic vessels to the sentinel lymph node (sLN). This process facilitates tumor cell spread across the body. Here, we characterized the innate inflammatory response to melanoma in the metastatic microenvironment of the sLN. We found that macrophages located in the subcapsular sinus (SS) produced protumoral IL1α after recognition of tumoral antigens. Moreover, we confirmed that the elimination of LN macrophages or the administration of an IL1α-specific blocking antibody reduced metastatic spread. To understand the mechanism of action of IL1α in the context of the sLN microenvironment, we applied single-cell RNA sequencing to microdissected metastases obtained from animals treated with the IL1α-specific blocking antibody. Among the different pathways affected, we identified STAT3 as one of the main targets of IL1α signaling in metastatic tumor cells. Moreover, we found that the antitumoral effect of the anti-IL1α was not mediated by lymphocytes because Il1r1 knockout mice did not show significant differences in metastasis growth. Finally, we found a synergistic antimetastatic effect of the combination of IL1α blockade and STAT3 inhibition with stattic, highlighting a new immunotherapy approach to preventing melanoma metastasis.

Life-extended glycosylated IL-2 promotes Treg induction and suppression of autoimmunity.

IL-2 is the master-regulator cytokine for T cell dependent responses and is crucial for proliferation and survival of T cells. However, IL-2-based treatments remained marginal, in part due to short half-life. Thus, we aimed to extend IL-2 half-life by flanking the IL-2 core with sequences derived from the extensively glycosylated hinge region of the NCR2 receptor. We termed this modified IL-2: "S2A". Importantly, S2A blood half-life was extended 14-fold compared to the clinical grade IL-2, Proleukin. Low doses inoculation of S2A significantly enhanced induction of Tregs (CD4+ Regulatory T cells) in vivo, as compared to Proleukin, while both S2A and Proleukin induced low levels of CD8+ T cells. In a B16 metastatic melanoma model, S2A treatment was unable to reduce the metastatic capacity of B16 melanoma, while enhancing induction and recruitment of Tregs, compared to Proleukin. Conversely, in two autoimmune models, rheumatoid arthritis and DSS-induced colitis, S2A treatment significantly reduced the progression of disease compared to Proleukin. Our results suggest new avenues for generating long-acting IL-2 for long-standing treatment and a new technique for manipulating short-life proteins for clinical and research uses.

Interleukin-1α dependent survival of cardiac fibroblasts is associated with StAR/STARD1 expression and improved cardiac remodeling and function after myocardial infarction.

AIMS: One unaddressed aspect of healing after myocardial infarction (MI) is how non-myocyte cells that survived the ischemic injury, keep withstanding additional cellular damage by stress forms typically arising during the post-infarction inflammation. Here we aimed to determine if cell survival is conferred by expression of a mitochondrial protein novel to the cardiac proteome, known as steroidogenic acute regulatory protein, (StAR/STARD1). Further studies aimed to unravel the regulation and role of the non-steroidogenic cardiac StAR after MI. METHODS AND RESULTS: Following permanent ligation of the left anterior descending coronary artery in mouse heart, timeline western blot analyses showed that StAR expression corresponds to the inflammatory response to MI. Following the identification of StAR in mitochondria of cardiac fibroblasts in culture, confocal microscopy immunohistochemistry (IHC) identified StAR expression in left ventricular (LV) activated interstitial fibroblasts, adventitial fibroblasts and endothelial cells. Further work with the primary fibroblasts model revealed that interleukin-1α (IL-1α) signaling via NF-κB and p38 MAPK pathways efficiently upregulates the expression of the Star gene products. At the functional level, IL-1α primed fibroblasts were protected against apoptosis when exposed to cisplatin mimicry of in vivo apoptotic stress; yet, the protective impact of IL-1α was lost upon siRNA mediated StAR downregulation. At the physiological level, StAR expression was nullified during post-MI inflammation in a mouse model with global IL-1α deficiency, concomitantly resulting in a 4-fold elevation of apoptotic fibroblasts. Serial echocardiography and IHC studies of mice examined 24 days after MI revealed aggravation of LV dysfunction, LV dilatation, anterior wall thinning and adverse tissue remodeling when compared with loxP control hearts. CONCLUSIONS: This study calls attention to overlooked aspects of cellular responses evolved under the stress conditions associated with the default inflammatory response to MI. Our observations suggest that LV IL-1α is cardioprotective, and at least one mechanism of this action is mediated by induction of StAR expression in border zone fibroblasts, which renders them apoptosis resistant. This acquired survival feature also has long-term ramifications on the heart recovery by diminishing adverse remodeling and improving the heart function after MI.

Proinflammatory Macrophages Promote Multiple Myeloma Resistance to Bortezomib Therapy.

Multiple myeloma (MM) is a plasma cell neoplasia commonly treated with proteasome inhibitors such as bortezomib. Although bortezomib has demonstrated enhanced survival benefit, some patients relapse and subsequently develop resistance to such therapy. Here, we investigate the mechanisms underlying relapse and refractory MM following bortezomib treatment. We show that bortezomib-exposed proinflammatory macrophages promote an enrichment of MM-tumor-initiating cells (MM-TIC) both in vitro and in vivo. These effects are regulated in part by IL1ß, as blocking the IL1ß axis by a pharmacologic or genetic approach abolishes bortezomib-induced MM-TIC enrichment. In MM patients treated with bortezomib, high proinflammatory macrophages in the bone marrow negatively correlate with survival rates (HR, 1.722; 95% CI, 1.138-2.608). Furthermore, a positive correlation between proinflammatory macrophages and TICs in the bone marrow was also found. Overall, our results uncover a protumorigenic cross-talk involving proinflammatory macrophages and MM cells in response to bortezomib therapy, a process that enriches the MM-TIC population. IMPLICATIONS: Our findings suggest that proinflammatory macrophages in bone marrow biopsies represent a potential prognostic biomarker for acquired MM resistance to bortezomib therapy.

Blocking IL-1ß reverses the immunosuppression in mouse breast cancer and synergizes with anti-PD-1 for tumor abrogation.

Interleukin-1ß (IL-1ß) is abundant in the tumor microenvironment, where this cytokine can promote tumor growth, but also antitumor activities. We studied IL-1ß during early tumor progression using a model of orthotopically introduced 4T1 breast cancer cells. Whereas there is tumor progression and spontaneous metastasis in wild-type (WT) mice, in IL-1ß-deficient mice, tumors begin to grow but subsequently regress. This change is due to recruitment and differentiation of inflammatory monocytes in the tumor microenvironment. In WT mice, macrophages heavily infiltrate tumors, but in IL-1ß-deficient mice, low levels of the chemokine CCL2 hamper recruitment of monocytes and, together with low levels of colony-stimulating factor-1 (CSF-1), inhibit their differentiation into macrophages. The low levels of macrophages in IL-1ß-deficient mice result in a relatively high percentage of CD11b+ dendritic cells (DCs) in the tumors. In WT mice, IL-10 secretion from macrophages is dominant and induces immunosuppression and tumor progression; in contrast, in IL-1ß-deficient mice, IL-12 secretion by CD11b+ DCs prevails and supports antitumor immunity. The antitumor immunity in IL-1ß-deficient mice includes activated CD8+ lymphocytes expressing IFN-γ, TNF-α, and granzyme B; these cells infiltrate tumors and induce regression. WT mice with 4T1 tumors were treated with either anti-IL-1ß or anti-PD-1 Abs, each of which resulted in partial growth inhibition. However, treating mice first with anti-IL-1ß Abs followed by anti-PD-1 Abs completely abrogated tumor progression. These data define microenvironmental IL-1ß as a master cytokine in tumor progression. In addition to reducing tumor progression, blocking IL-1ß facilitates checkpoint inhibition.

Inflammation in the pleural cavity following injection of multi-walled carbon nanotubes is dependent on their characteristics and the presence of IL-1 genes.

Upon inhalation, multi-walled carbon nanotubes (MWCNTs) may reach the subpleura and pleural spaces, and induce pleural inflammation and/or mesothelioma in humans. However, the mechanisms of MWCNT-induced pathology after direct intrapleural injections are still only partly elucidated. In particular, a role of the proinflammatory interleukin-1 (IL-1) cytokines in pleural inflammation has so far not been published. We examined the MWCNT-induced pleural inflammation, gene expression abnormalities, and the modifying role of IL-1α and ß cytokines following intrapleural injection of two types of MWCNTs (CNT-1 and CNT-2) compared with crocidolite asbestos in IL-1 wild-type (WT) and IL-1α/ß KO (IL1-KO) mice. Histopathological examination of the pleura 28 days post-exposure revealed mesothelial cell hyperplasia, leukocyte infiltration, and fibrosis occurring in the CNT-1 (Mitsui-7)-exposed group. The pleura of these mice also showed the greatest changes in mRNA and miRNA expression levels, closely followed by CNT-2. In addition, the CNT-1-exposed group also presented the greatest infiltrations of leukocytes and proliferation of fibrous tissue. WT mice were more prone to development of sustained inflammation and fibrosis than IL1-KO mice. Prominent differences in genetic and epigenetic changes were also observed between the two genotypes. In conclusion, the fibrotic response to MWCNTs in the pleura depends on the particles' physico-chemical properties and on the presence or absence of the IL-1 genes. Furthermore, we found that CNT-1 was the most potent inducer of inflammatory responses, followed by CNT-2 and crocidolite asbestos.

Microglial Activation Is Modulated by Captopril: in Vitro and in Vivo Studies.

The renin-angiotensin system (RAS) is an important peripheral system involved in homeostasis modulation, with angiotensin II (Ang II) serving as the main effector hormone. The main enzyme involved in Ang II formation is angiotensin-converting enzyme (ACE). ACE inhibitors (ACEIs) such as captopril (Cap) are predominantly used for the management of hypertension. All of the components of the RAS have also been identified in brain. Centrally located hormones such as Ang II can induce glial inflammation. Moreover, in Alzheimer's disease (AD) models, where glial inflammation occurs and is thought to contribute to the propagation of the disease, increased levels of Ang II and ACE have been detected. Interestingly, ACE overexpression in monocytes, migrating to the brain was shown to prevent AD cognitive decline. However, the specific effects of captopril on glial inflammation and AD remain obscure. In the present study, we investigated the effect of captopril, given at a wide concentration range, on inflammatory mediators released by lipopolysaccharide (LPS)-treated glia. In the current study, both primary glial cells and the BV2 microglial cell line were used. Captopril decreased LPS-induced nitric oxide (NO) release from primary mixed glial cells as well as regulating inducible NO synthase (iNOS) expression, NO, tumor necrosis factor-α (TNF-α) and induced interleukin-10 (IL-10) production by BV2 microglia. We further obtained data regarding intranasal effects of captopril on cortical amyloid ß (Aß) and CD11b expression in 5XFAD cortex over three different time periods. Interestingly, we noted decreases in Aß burden in captopril-treated mice over time which was paralleled by increased microglial activation. These results thus shed light on the neuroprotective role of captopril in AD which might be related to modulation of microglial activation.

Interleukin 1α-Deficient Mice Have an Altered Gut Microbiota Leading to Protection from Dextran Sodium Sulfate-Induced Colitis.

Inflammatory bowel diseases (IBD) are a group of chronic inflammatory disorders of the intestine, with as-yet-unclear etiologies, affecting over a million people in the United States alone. With the emergence of microbiome research, numerous studies have shown a connection between shifts in the gut microbiota composition (dysbiosis) and patterns of IBD development. In a previous study, we showed that interleukin 1α (IL-1α) deficiency in IL-1α knockout (KO) mice results in moderate dextran sodium sulfate (DSS)-induced colitis compared to that of wild-type (WT) mice, characterized by reduced inflammation and complete healing, as shown by parameters of weight loss, disease activity index (DAI) score, histology, and cytokine expression. In this study, we tested whether the protective effects of IL-1α deficiency on DSS-induced colitis correlate with changes in the gut microbiota and whether manipulation of the microbiota by cohousing can alter patterns of colon inflammation. We analyzed the gut microbiota composition in both control (WT) and IL-1α KO mice under steady-state homeostasis, during acute DSS-induced colitis, and after recovery using 16S rRNA next-generation sequencing. Additionally, we performed cohousing of both mouse groups and tested the effects on the microbiota and clinical outcomes. We demonstrate that host-derived IL-1α has a clear influence on gut microbiota composition, as well as on severity of DSS-induced acute colon inflammation. Cohousing both successfully changed the gut microbiota composition and increased the disease severity of IL-1α-deficient mice to levels similar to those of WT mice. This study shows a strong and novel correlation between IL-1α expression, microbiota composition, and clinical outcomes of DSS-induced colitis. IMPORTANCE Here, we show a connection between IL-1α expression, microbiota composition, and clinical outcomes of DSS-induced colitis. Specifically, we show that the mild colitis symptoms seen in IL-1α-deficient mice following administration of DSS are correlated with the unique gut microbiota compositions of the mice. However, when these mice are exposed to WT microbiota by cohousing, their gut microbiota composition returns to resemble that of WT mice, and their disease severity increases significantly. As inflammatory bowel diseases are such common diseases, with limited effective treatments to date, there is a great need to better understand the interactions between microbiota composition, the immune system, and colitis. This study shows correlation between microbiota composition and DSS resistance; it may potentially lead to the development of improved probiotics for IBD treatment.

Candesartan ameliorates brain inflammation associated with Alzheimer's disease.

AIMS: Alzheimer's disease (AD) pathology is associated with brain inflammation involving microglia and astrocytes. The renin-angiotensin system contributes to brain inflammation associated with AD pathology. This study aimed to investigate the role of candesartan, an angiotensin II type 1 receptor blocker, in modulation of glial functions associated with AD. METHODS: Focusing on the role of candesartan in glial inflammation, we evaluated inflammatory mediators' levels, secreted by lipopolysaccharide-induced microglia following candesartan treatment. Also, short-term intranasal candesartan effects on amyloid burden and microglial activation were investigated in 5 familial AD mice. RESULTS: Candesartan showed anti-inflammatory effects and shifted microglial activation toward a more neuroprotective phenotype. Candesartan decreased the lipopolysaccharide-induced nitric oxide synthase and cyclooxygenase-2 expression levels, which was accompanied by an induction of arginase-1 expression levels and enhanced Aß1-42 uptake by microglia. Moreover, intranasally administered candesartan to AD mice model significantly reduced the amyloid burden and microglia activation in the hippocampus. CONCLUSIONS: These results thus shed light on the neuroprotective role of candesartan in the early stage of AD, which might relate to modulation of microglial activation states.

Targeting the Tumor Microenvironment by Intervention in Interleukin-1 Biology.

The importance of anti-tumor immunity in the outcome of cancer is now unequivocally established and recent achivements in the field have stimulated the development of new immunotherapeutical approaches. In invasive tumors, widespread inflammation promotes invasiveness and concomitantly also inhibits anti-tumor immune responses. We suggest that efficient tumor treatment should target both the malignant cells and the tumor microenvironment. Interleukin-1 (IL-1) is a pro-inflammatory as well as an immunostimulatory cytokine that is abundant in the tumor microenvironment. Manipulation of IL-1 can thus serve as an immunotherapeutical approach to reduce inflammation/immunosuppression and thus enhance anti-tumor immunity. The two major IL-1 agonistic molecules are IL-1α and IL-1ß, which bind to the same IL-1 signaling receptor and induce the same array of biological activities. The IL-1 receptor antagonist (IL-Ra) is a physiological inhibitor of IL-1 that binds to its receptor without transmition of activation signals and thus serves as a decoy target. We have demonstrated that IL-1α and IL-1ß are different in terms of the producing cells and their compartmentalization and the amount. IL-1α is mainly expressed intracellularly, in the cytosol, in the nucleus or exposed on the cell membrane, however, it is rarely secreted. IL-1ß is active only as a secreted molecule that is mainly produced by activated myeloid cells. We have shown different functions of IL-1α and IL-1ß in the malignant process. Thus, in its membrane- associated form, IL-1α is mainly immunostimulatory, while IL-1ß that is secreted into the tumor microenvironment is mainly pro-inflammatory and promotes tumorigenesis, tumor invasiveness and immunosuppression. These distinct functions of the IL-1 agonistic molecules are mainly manifested in early stages of tumor development and the patterns of their expression dictate the direction of the malignant process. Here, we suggest that IL-1 modulation can serve as an effective mean to tilt the balance between inflammation and immunity in tumor sites, towards the latter. Different agents that neutralize IL-1, mainly the IL-Ra and specific antibodies, exist. They are safe and FDA-approved. The IL-1Ra has been widely and successfully used in patients with Rheumatoid arthritis, autoinflammatory diseases and various other diseases that have an inflammatory component. Here, we provide the rationale and experimental evidence for the use of anti-IL-1 agents in cancer patients, following first line therapy to debulk the major tumor's mass. The considerations and constraints of using anti-IL-1 treatments in cancer are also discussed. We hope that this review will stimulate studies that will fasten the application of IL-1 neutralization at the bedside of cancer patients.

Immunotherapeutic approaches of IL-1 neutralization in the tumor microenvironment.

IL-1 is a pleiotropic cytokine that controls inflammation, immunity, and hemopoiesis. The major IL-1 agonistic molecules are IL-1α and IL-1ß, which bind to IL-1R type I (IL-1R1) and induce similar biologic functions. The IL-1R antagonist (IL-1Ra) is a physiologic inhibitor of IL-1R1 signaling. In the tumor microenvironment, IL-1 is expressed by malignant, stromal, and infiltrating cells and supports tumor invasiveness and progression. We have shown that in the tumor microenvironment, the IL-1 agonistic molecules act different as a result of their local amounts and their compartmentalization within the producing cells. IL-1ß is produced mainly by myeloid cells upon inflammatory stimulation and is active as a mature, secreted molecule. The precursor of IL-1α (ProIL-1α) is biologically active; it is constitutively expressed in diverse tissue cells in basal levels, and its expression increases during stress or inflammation. ProIL-1α is mainly located in the cytosol or it is membrane associated. ProIL-1α also translocates into the nucleus and binds to chromatin. ProIL-1α is rarely actively secreted but is released from necrotizing tissues and serves as "alarmin" for initiation of inflammation. In the tumor microenvironment, IL-1ß promotes tumorigenesis, tumor invasiveness, and immunosuppression. On the other hand, membrane-associated forms of IL-1α support the development of anti-tumor immunity. In cancer patients, both IL-1 agonistic molecules coexist and interact with each other. Here, we discuss the role of IL-1 agonistic molecules in tumor progression and their potential to serve as targets in anti-tumor immunotherapeutic approaches. Our notion on the optimal conditions for IL-1 manipulation is also discussed.

Alarmins: Feel the Stress.

Over the last decade, danger-associated molecular pattern molecules, or alarmins, have been recognized as signaling mediators of sterile inflammatory responses after trauma and injury. In contrast with the accepted passive release models suggested by the "danger hypothesis," it was recently shown that alarmins can also directly sense and report damage by signaling to the environment when released from live cells undergoing physiological stress, even without loss of subcellular compartmentalization. In this article, we review the involvement of alarmins such as IL-1α, IL-33, IL-16, and high-mobility group box 1 in cellular and physiological stress, and suggest a novel activity of these molecules as central initiators of sterile inflammation in response to nonlethal stress, a function we denote "stressorins." We highlight the role of posttranslational modifications of stressorins as key regulators of their activity and propose that targeted inhibition of stressorins or their modifiers could serve as attractive new anti-inflammatory treatments for a broad range of diseases.

MABp1 as a novel antibody treatment for advanced colorectal cancer: a randomised, double-blind, placebo-controlled, phase 3 study.

BACKGROUND: MABp1, an antibody that targets interleukin 1α, has been associated with antitumour activity and relief of debilitating symptoms in patients with advanced colorectal cancer. We sought to establish the effect of MABp1 with a new primary endpoint in patients with advanced colorectal cancer. METHODS: Eligible patients for the double-blind phase of this ongoing, placebo-controlled, randomised, phase 3 trial, had metastatic or unresectable disease, Eastern Cooperative Oncology Group performance status score 1 or 2, systemic inflammation, weight loss, and other disease-related morbidities associated with poor prognosis, and were refractory to oxaliplatin and irinotecan. Patients were randomly assigned 2:1 to receive either MABp1 or placebo. Randomisation codes were obtained from a centrally held list via an interactive web response system. Patients received an intravenous infusion of 7·5 mg/kg MABp1 or placebo given every 2 weeks for 8 weeks. The primary endpoint was assessed in patients who received at least one dose of MABp1 or placebo (modified intention-to-treat population), and was a composite of stable or increased lean body mass and stability or improvement in two of three symptoms (pain, fatigue, or anorexia) at week 8 compared with baseline measurements. This study is registered with ClinicalTrials.gov, number NCT02138422. FINDINGS: Patients were enrolled between May 20, 2014, and Sept 2, 2015. The double-blind phase of the study was completed on Nov 3, 2015. Of 333 patients randomly assigned treatment, 207 received at least one dose of MABp1 and 102 at least one dose of placebo. 68 (33%) and 19 (19%) patients, respectively, achieved the primary endpoint (relative risk 1·76, 95% CI 1·12-2·77, p=0·0045). The most common grade 3-4 adverse events in the MABp1 group compared with in the placebo group were anaemia (eight [4%] of 207 vs five [5%] of 102 patients), increased concentration of alkaline phosphatase (nine [4%] vs two [2%]), fatigue (six [3%] vs seven [7%]), and increased concentration of aspartate aminotransferase (six [3%] vs two [2%]). After 8 weeks, 17 (8%) patients in the MABp1 group and 11 (11%) in the placebo group had died, but no death was judged to be related to treatment. The incidence of serious adverse events was not significantly different in the MABp1 group and placebo groups (47 [23%] vs 33 [32%], p=0·07). INTERPRETATION: The primary endpoint was a useful means of measuring clinical performance in patients. MABp1 might represent a new standard in the management of advanced colorectal cancer. FUNDING: XBiotech.