Cytokines and proteases in invasive processes: molecular similarities between inflammation and cancer

The Role of Cytokines in Cholesterol Accumulation in Cells and Atherosclerosis Progression

Atherosclerosis is the most common cardiovascular disease and is the number one cause of death worldwide. Today, atherosclerosis is a multifactorial chronic inflammatory disease with an autoimmune component, accompanied by the accumulation of cholesterol in the vessel wall and the formation of atherosclerotic plaques, endothelial dysfunction, and chronic inflammation. In the process of accumulation of atherogenic lipids, cells of the immune system, such as monocytes, macrophages, dendritic cells, etc., play an important role, producing and/or activating the production of various cytokines—interferons, interleukins, chemokines. In this review, we have tried to summarize the most important cytokines involved in the processes of atherogenesis.

Overview of Evidence-Based Chemotherapy for Oral Cancer: Focus on Drug Resistance Related to the Epithelial-Mesenchymal Transition

The increasing incidence of resistance to chemotherapeutic agents has become a major issue in the treatment of oral cancer (OC). Epithelial-mesenchymal transition (EMT) has attracted a great deal of attention in recent years with regard to its relation to the mechanism of chemotherapy drug resistance. EMT-activating transcription factors (EMT-ATFs), such as Snail, TWIST, and ZEB, can activate several different molecular pathways, e.g., PI3K/AKT, NF-κB, and TGF-β. In contrast, the activated oncological signal pathways provide reciprocal feedback that affects the expression of EMT-ATFs, resulting in a peritumoral extracellular environment conducive to cancer cell survival and evasion of the immune system, leading to resistance to multiple chemotherapeutic agents. We present an overview of evidence-based chemotherapy for OC treatment based on the National Comprehensive Cancer Network (NCCN) Chemotherapy Order Templates. We focus on the molecular pathways involved in drug resistance related to the EMT and highlight the signal pathways and transcription factors that may be important for EMT-regulated drug resistance. Rapid progress in antitumor regimens, together with the application of powerful techniques such as high-throughput screening and microRNA technology, will facilitate the development of therapeutic strategies to augment chemotherapy.

Immunomodulatory nanosystems for treating inflammatory diseases

Inflammatory disease (ID) is an umbrella term encompassing all illnesses involving chronic inflammation as the central manifestation of pathogenesis. These include, inflammatory bowel diseases, hepatitis, pulmonary disorders, atherosclerosis, myocardial infarction, pancreatitis, arthritis, periodontitis, psoriasis. The IDs create a severe burden on healthcare and significantly impact the global socio-economic balance. Unfortunately, the standard therapies that rely on a combination of anti-inflammatory and immunosuppressive agents are palliative and provide only short-term relief. In contrast, the emerging concept of immunomodulatory nanosystems (IMNs) has the potential to address the underlying causes and prevent reoccurrence, thereby, creating new opportunities for treating IDs. The IMNs offer exquisite ability to precisely modulate the immune system for a therapeutic advantage. The nano-sized dimension of IMNs allows them to efficiently infiltrate lymphatic drainage, interact with immune cells, and subsequently to undergo rapid endocytosis by hyperactive immune cells (HICs) at inflamed sites. Thus, IMNs serve to restore dysfunctional or HICs and alleviate the inflammation. We identified that different IMNs exert their immunomodulatory action via either of the seven mechanisms to modulate; cytokine production, cytokine neutralization, cellular infiltration, macrophage polarization, HICs growth inhibition, stimulating T-reg mediated tolerance and modulating oxidative-stress. In this article, we discussed representative examples of IMNs by highlighting their rationalization, design principle, and mechanism of action in context of treating various IDs. Lastly, we highlighted technical challenges in the application of IMNs and explored the future direction of research, which could potentially help to overcome those challenges.

Expression and function of interleukin-1β is required for hamster blastocyst hatching: Involvement of hatching-associated cathepsin proteases

In mammals, the phenomenon of blastocyst hatching is an essential prerequisite for successful implantation. Blastocyst hatching is regulated by various molecules. Of them, cytokines, expressed by preimplantation embryos, are thought to be functionally important in blastocyst development and hatching, but their mechanistic roles are not clearly understood. Here, we examined the involvement of two cytokines, namely, interleukin-1β (IL-1β) and its natural antagonist, IL-1ra, in blastocyst hatching in the golden hamster. Blastocysts expressed both cytokines and their receptor, IL-1rt1. Supplementation of IL-1β to cultured eight-cell embryos improved blastocyst hatching (84.1% ± 4.2% vs. 66.6% ± 6.8%; treated vs. control). This improvement was diminished by IL-1ra treatment (23.6% ± 12.9% vs. 76.4% ± 12.9%; treated vs. control). Interestingly, IL-1β-treated embryos showed increased messenger RNA expression of zonalytic proteases, that is, cathepsin-L and -B by 1.9 ± 0.5- and 3.5 ± 0.1-folds, respectively. This was accompanied by their increased enzyme activities; cathepsin-L by 2.8 ± 0.7 fold and -B by 2.3 ± 0.7-fold. Strikingly, proteases and IL-1β were intensely colocalized to trophectodermal projections of hatching blastocysts. This is the first report to show the involvement of embryonic IL-1β in regulating hatching-associated proteases required for blastocyst hatching.

Trigger-responsive engineered-nanocarriers and image-guided theranostics for rheumatoid arthritis

Rheumatoid Arthritis (RA), one of the leading causes of disability due to progressive autoimmune destruction of synovial joints, affects ∼1% of the global population. Standard therapy helps in reducing inflammation and delaying the progression of RA but is limited by non-responsiveness on long-term use and several side-effects. The conventional nanocarriers (CNCs), to some extent, minimize toxicity associated with free drug administration while improving the therapeutic efficacy. However, the uncontrolled release of the encapsulated drug even at off-targeted organs limits the application of CNCs. To overcome these challenges, trigger-responsive engineered nanocarriers (ENCs) have been recently explored for RA treatment. Unlike CNCs, ENCs enable precise control over on-demand drug release due to endogenous triggers in arthritic paws like pH, enzyme level, oxidative stress, or exogenously applied triggers like near-infrared light, magnetic field, ultrasonic waves, etc. As the trigger is selectively applied to the inflamed joint, it potentially reduces toxicity at off-target locations. Moreover, ENCs have been strategically coupled with imaging probe(s) for simultaneous monitoring of ENCs inside the body and facilitate an 'image-guided-co-trigger' for site-specific action in arthritic paws. In this review, the progress made in recently emerging 'trigger-responsive' and 'image-guided theranostics' ENCs for RA treatment has been explored with emphasis on the design strategies, mechanism, current status, challenges, and translational perspectives.

MMP-10 and TIMP-1 as indicators of severe sepsis in adult hematological patients with febrile neutropenia

Commonly used indicators of sepsis are nonspecific and insufficient for predicting the course of febrile neutropenia (FN) in hematological patients. We analyzed data from 91 adult FN patients who received intensive chemotherapy for acute myeloid leukemia or autologous stem cell transplantation. Compared to patients with non-severe sepsis, patients with severe sepsis had significantly higher serum levels of tissue inhibitor of metalloproteinases-1 on the day of first occurrence of fever (day 0: 172 vs. 112 µg/L, p= .002) and for the two following days (day 1: 219 vs. 128 µg/L, p< .001; day 2: 443 vs. 128 µg/L, p= .001), and significantly higher serum levels of matrix metalloproteinase-10 on day 1 (1975 vs. 876 ng/L, p= .001) and day 2 (2020 vs. 841 ng/L, p< .001). We conclude that the measurement of these biomarkers may be useful in predicting the severity of sepsis in FN patients.

MMP Inhibitors: Experimental and Clinical Studies

Matrix metalloproteases (MMPs) are a family of structurally related enzymes that are capable of degrading proteins of the extracellular matrix. These enzymes play a role in tissue remodelling associated with both physiological and pathogenic processes. A high expression of MMPs is associated with cancer malignancy: it is related to the tumor's ability to metastasize and to the process of angiogenesis. Treatment with MMP inhibitors alone or in combination with cytotoxic therapy is an interesting novel approach to control tumor progression. The expected mechanism of action of these compounds and the difference in side effects compared to cytotoxic drugs make the definition of endpoints and the assessment of response difficult. Furthermore, it is not yet clear whether tumor vascularization or, more specifically, MMP expression/activation should be a criterion of eligibility for this kind of treatment. This review provides an overview of the characteristics of MMPs and their role in tumor progression, metastasis and angiogenesis. Preclinical and clinical studies with synthetic MMP inhibitors are described. The presence of MMPs in biological fluids of patients and their use in prognostic evaluation and in determining the efficacy of treatment with MMP inhibitors is discussed.

Application of Sodium Selenite in the Prevention and Treatment of Cancers

Selenium is an essential trace element that occurs in nature, in both inorganic and organic forms. This element participates in numerous biochemical processes, including antioxidant potential, but the mechanism of its anti-cancer action is still not well known. It should be noted that the anti-cancer properties of selenium depends on its chemical form, therapeutic doses, and the tumor type. Higher nutritional doses of selenium can stimulate human immune system. There are several hypotheses concerning the anticancer activity of selenium, including oxidation of sulfhydryl groups in proteins causing their conformational alterations. Conformational changes in proteins have the ability to weaken the activity of enzymes involved in the metabolism of cancer cells. In case of human fibrinogen sodium selenite, but not selenate, it inhibits protein disulfide exchange reactions, thus preventing formation of a hydrophobic polymer termed parafibrin, circulatory accumulation, of which is associated with numerous degenerative diseases. Parafibrin can specifically form a protein coat around tumor cells that is completely resistant to degradation induced with lymphocyte protease. In this way, cancer cells become protected against destruction by the organism's immune system. Other possible mechanisms of anticancer action of selenium are being still investigated.

Epigenetic regulation of metalloproteinases and their inhibitors in rotator cuff tears

Rotator cuff tear is a common orthopedic condition. Metalloproteinases (MMP) and their inhibitors (TIMP) seem to play a role in the development of joint injuries and in the failure of tissue healing. However, the mechanisms of regulation of gene expression in tendons are still unknown. Epigenetic mechanisms, such as DNA methylation and microRNAs regulation, are involved in the dynamic control of gene expression. Here, the mRNA expression and DNA methylation status of MMPs (MMP1, MMP2, MMP3, MMP9, MMP13, and MMP14) and TIMPs (TIMP1-3) and the expression of miR-29 family members in ruptured supraspinatus tendons were compared with non-injured tendons of individuals without this lesion. Additionally, the gene expression and methylation status at the edge of the ruptured tendon were compared with macroscopically non-injured rotator cuff tendon samples from the anterior and posterior regions of patients with tendon tears. Moreover, the possible associations between the molecular alterations and the clinical and histologic characteristics were investigated. Dysregulated expression and DNA methylation of MMP and TIMP genes were found across the rotator cuff tendon samples of patients with supraspinatus tears. These alterations were influenced at least in part by age at surgery, sex, smoking habit, tear size, and duration of symptoms. Alterations in the studied MMP and TIMP genes may contribute to the presence of microcysts, fissures, necrosis, and neovascularization in tendons and may thus be involved in the tendon healing process. In conclusion, MMPs and their inhibitors are regulated by epigenetic modifications and may play a role in rotator cuff tears.

Stimulation of hepatocarcinogenesis by neutrophils upon induction of oncogenic kras expression in transgenic zebrafish

BACKGROUND & AIMS

Chronic inflammation is a major etiological factor for hepatocellular carcinoma (HCC), but how immune cells respond in the initiation of hepatocarcinogenesis remains uncharacterized. This study aims to investigate the response and roles of neutrophils in early hepatocarcinogenesis.

METHODS

By inducible expression of oncogenic kras(V12) in hepatocytes in transgenic zebrafish combined with live imaging of neutrophils in transparent larvae, the response of neutrophils to oncogenic liver was characterized and their roles investigated by pharmaceutical and genetic manipulations.

RESULTS

We found a rapid recruitment of neutrophils to the liver upon induction of kras(V12) expression. Pharmaceutical stimulation of neutrophils resulted in further increases of neutrophils in oncogenic livers, liver size and tumor severity, while inhibition of neutrophils caused decreases of liver-associated neutrophils and liver size. Time-lapse video indicated that neutrophils had a stagnant migratory pattern meandering along the tumor edge but became relatively stationary upon entering the kras(V12)-expressing liver. Both oncogenic hepatocytes and tumor-associated neutrophils (TANs) were isolated via fluorescence-activated cell sorting. Molecular analyses indicated a pro-inflammatory microenvironment, as marked by increased tgfβ1a expression in kras(V12)-expressing hepatocytes and a loss of anti-tumor activities in TANs. Depletion of Tgf-β significantly reduced the number of TANs and the size of oncogenic liver.

CONCLUSIONS

An inflammatory cue from oncogenic hepatocytes upon induction of kras(V12) expression causes a rapid recruitment of neutrophils to oncogenic liver and the neutrophils play a promoting role in early hepatocarcinogenesis.

Oncostatin M binds to extracellular matrix in a bioactive conformation: implications for inflammation and metastasis

Oncostatin M (OSM) is an interleukin-6-like inflammatory cytokine reported to play a role in a number of pathological processes including cancer. Full-length OSM is expressed as a 26 kDa protein that can be proteolytically processed into 24 kDa and 22 kDa forms via removal of C-terminal peptides. In this study, we examined both the ability of OSM to bind to the extracellular matrix (ECM) and the activity of immobilized OSM on human breast carcinoma cells. OSM was observed to bind to ECM proteins collagen types I and XI, laminin, and fibronectin in a pH-dependent fashion, suggesting a role for electrostatic bonds that involves charged amino acids of both the ECM and OSM. The C-terminal extensions of 24 kDa and 26 kDa OSM, which contains six and thirteen basic amino acids, respectively, enhanced electrostatic binding to ECM at pH 6.5-7.5 when compared to 22 kDa OSM. The highest levels of OSM binding to ECM, though, were observed at acidic pH 5.5, where all forms of OSM bound to ECM proteins to a similar extent. This indicates additional electrostatic binding properties independent of the OSM C-terminal extensions. The reducing agent dithiothreitol also inhibited the binding of OSM to ECM suggesting a role for disulfide bonds in OSM immobilization. OSM immobilized to ECM was protected from cleavage by tumor-associated proteases and maintained activity following incubation at acidic pH for extended periods of time. Importantly, immobilized OSM remained biologically active and was able to induce and sustain the phosphorylation of STAT3 in T47D and ZR-75-1 human breast cancer cells over prolonged periods, as well as increase levels of STAT1 and STAT3 protein expression. Immobilized OSM also induced epithelial-mesenchymal transition-associated morphological changes in T47D cells. Taken together, these data indicate that OSM binds to ECM in a bioactive state that may have important implications for the development of chronic inflammation and tumor metastasis.

A high M1/M2 ratio of tumor-associated macrophages is associated with extended survival in ovarian cancer patients

BACKGROUND

Tumor-associated macrophages (TAMs) are classified into two major phenotypes, M1 and M2. M1 TAMs suppress cancer progression, while M2 TAMs promote it. However, little is known regarding the role of TAMs in the development of ovarian cancer. Here, we investigated the relationship between TAM distribution patterns (density, microlocalization, and differentiation) and ovarian cancer histotypes, and we explored whether altered TAM distribution patterns influence long-term outcomes in ovarian cancer patients.

METHODS

A total of 112 ovarian cancer patients were enrolled in this study, and the subjects were divided into two groups according to their survival (< 5 years vs. ≥ 5 years). Immunohistochemistry and immunofluorescence were used to determine the density, microlocalization, and differentiation status of TAMs in ovarian cancer tissues for each histotype. Kaplan-Meier survival and multivariate Cox regression analyses were used to evaluate the prognostic significance of TAM-related parameters in ovarian cancer.

RESULTS

TAMs most frequently infiltrated into the cancer tissue of the serous histotype, followed by mucinous, undifferentiated, endometrioid, and clear cell histotypes (p = 0.049). The islet/stroma ratio of total TAMs varied among the cancer histotypes, with mucinous and undifferentiated cancers displaying the lowest and highest ratios, respectively (p = 0.005). The intratumoral TAM density significantly increased with increasing cancer stage and grade (p = 0.023 and 0.006, respectively). However, the overall M1/M2 TAM ratio decreased as the cancer stage increased (p = 0.012). In addition, the intra-islet M1/M2 ratio inversely correlated with the residual site size (p = 0.004). Among the TAM-related parameters, only the increased overall and intra-islet M1/M2 TAM ratios displayed prognostic significance in both the Kaplan-Meier survival and multivariate Cox regression analyses; however, the values of these two parameters did not differ significantly among the cancer histotypes.

CONCLUSIONS

The patients with increased overall or intra-islet M1/M2 TAM ratios presented with an improved 5-year prognosis. Nevertheless, the TAM distribution patterns did not influence the overall outcomes of different ovarian cancer histotypes.

Screening of serine protease inhibitors with antimicrobial activity using iron oxide nanoparticles functionalized with dextran conjugated trypsin and in silico analyses of bacterial serine protease inhibition

Plants produce a variety of proteins and peptides which are involved in their defense against pathogens. Serine protease inhibitors are a well-established class of inhibitors correlated with plant defense. Increased levels of protease inhibitors delay cell damage and expand the cell's life-span. Recently, the rapid emergence of antibiotic-resistant microbial pathogens has prompted immense interest in purifying novel antimicrobial proteins or peptides from plant sources. Usually, the purification of protease inhibitors is accomplished by salt-extraction, ultrafiltration and affinity chromatography. Here, we developed a novel approach based on iron oxide nanoparticles conjugated to dextran functionalized with trypsin beads that accelerate the quick screening and purification of antimicrobial peptides with serine protease inhibitor activity. The method described here also works for screening other inhibitors using particular protein kinases, and it is therefore a novel tool for use as the leading method in the development of novel antimicrobial agents with protease inhibitory activity. Finally, and no less important, molecular modelling and dynamics studies of a homologous inhibitor studied here with Escherichia coli trypsin and chymotrypsin are provided in order to shed some light on inhibitor-enzyme interactions.

Victory and defeat in the induction of a therapeutic response through vaccine therapy for human and canine brain tumors: a review of the state of the art

Anti-tumor immunotherapy using tumor lysate-based vaccines has made great advances over recent decades. Cancer vaccines aim to elicit adaptive immune responses through various pathways by providing tumor and tumor-associated antigens with an immune stimulant or adjuvant. These anti-tumor vaccines are therefore developed as personalized treatments. Utilizing tumors as a source of vaccine antigens in immunotherapy has demonstrated promising results with minimal toxicity. However, to date, researchers have failed to overcome the overpowering immune suppressive effects within the tumor microenvironment. Immune suppression occurs naturally via multiple mechanisms. These mechanisms serve an important homeostatic role restoring a normal tissue microenvironment following an inflammatory response. Due to these suppressive mechanisms and the inherent heterogeneity of tumors, it is imperative to then elicit and maintain a specific tumoricidal response if vaccine therapy or some other combination of reagents is chosen. In this review, we focus on the historical use of tumors as a source of antigens to elicit a tumoricidal response and the limitations encountered that prevent greater success in immunotherapy. We describe the advantages and disadvantages of various vaccines and their ineffectiveness due to tumor-induced immune suppression.

Design, syntheses, and characterization of pharmacophore based chemokine receptor CCR5 antagonists as anti prostate cancer agents

Accumulating evidence has shown multiple roles that chemokine receptor CCR5 may play to promote the progression of several types of cancer. The mechanism of such promotion is believed to involve chronic inflammation that creates a microenvironment which enhances tumor survival. Therefore, blocking CCR5 function with an antagonist may provide a novel treatment of cancers such as prostate cancer. Currently, several CCR5 antagonists are available, but all have been optimized for their inhibitory activity on HIV-1 cellular membrane invasion process rather than inhibition on cytoplasmic signaling pathways. Thus, there is need to develop CCR5 antagonists focusing on blockage of CCR5 downstream signaling and inhibition of CCR5 related prostate cancer proliferation and progression. In this report, a pharmacophore analysis was conducted based on docking studies of several known CCR5 antagonists in a CCR5 homology model. A unique structural skeleton for CCR5 antagonist was constructed and functionalized, resulting in a new series of small molecules to be synthesized and characterized. A combination of CCR5 calcium flux inhibition, anti prostate cancer cell proliferation, basal cytotoxicity, and in vivo animal model studies were applied to screen the newly synthesized compounds. Results from this study provided a potential lead compound for future CCR5 antagonist development focusing on prostate cancer therapy.

Inflammatory breast cancer: New factors contribute to disease etiology: A review

Inflammatory breast cancer (IBC) is a highly metastatic and fatal form of breast cancer. In fact, IBC is characterized by specific morphological, phenotypic, and biological properties that distinguish it from non-IBC. The aggressive behavior of IBC being more common among young women and the low survival rate alarmed researchers to explore the disease biology. Despite the basic and translational studies needed to understand IBC disease biology and identify specific biomarkers, studies are limited by few available IBC cell lines, experimental models, and paucity of patient samples. Above all, in the last decade, researchers were able to identify new factors that may play a crucial role in IBC progression. Among identified factors are cytokines, chemokines, growth factors, and proteases. In addition, viral infection was also suggested to participate in the etiology of IBC disease. In this review, we present novel factors suggested by different studies to contribute to the etiology of IBC and the proposed new therapeutic insights.

Thymoquinone suppresses metastasis of melanoma cells by inhibition of NLRP3 inflammasome

The inflammasome is a multi-protein complex which when activated regulates caspase-1 activation and IL-1β and IL-18 secretion. The NLRP3 (NACHT, LRR, and pyrin domain-containing protein 3) inflammasome is constitutively assembled and activated in human melanoma cells. We have examined the inhibitory effect of thymoquinone (2-isopropyl-5-methylbenzo-1,4-quinone), a major ingredient of black seed obtained from the plant Nigella sativa on metastatic human (A375) and mouse (B16F10) melanoma cell lines. We have assessed whether thymoquinone inhibits metastasis of melanoma cells by targeting NLRP3 subunit of inflammasomes. Using an in vitro cell migration assay, we found that thymoquinone inhibited the migration of both human and mouse melanoma cells. The inhibitory effect of thymoquinone on metastasis was also observed in vivo in B16F10 mouse melanoma model. The inhibition of migration of melanoma cells by thymoquinone was accompanied by a decrease in expression of NLRP3 inflammasome resulting in decrease in proteolytic cleavage of caspase-1. Inactivation of caspase-1 by thymoquinone resulted in inhibition of IL-1β and IL-18. Treatment of mouse melanoma cells with thymoquinone also inhibited NF-κB activity. Furthermore, inhibition of reactive oxygen species (ROS) by thymoquinone resulted in partial inactivation of NLRP3 inflammasome. Thus, thymoquinone exerts its inhibitory effect on migration of human and mouse melanoma cells by inhibition of NLRP3 inflammasome. Thus, our results indicate that thymoquinone can be a potential immunotherapeutic agent not only as an adjuvant therapy for melanoma, but also, in the control and prevention of metastatic melanoma.

Special issue commentary: the changing face of inflammation in the brain

The study of inflammation in the brain has been extended to include a wide range of conditions, but there remains plenty of argument over semantics and the precise definition of what constitutes inflammation in these pathologies. In this special issue, we sought to highlight the diversity of what is considered to be inflammation in the brain, and we have accepted that the presence of microglia cells with altered morphology remains a useful starting point. However, it is clear that whatever is the molecular expression profile that accompanies an activated microglial cell, it is not static and it is influenced by factors both intrinsic and extrinsic to the brain. This article is part of a Special Issue entitled 'Neuroinflammation in neurodegeneration and neurodysfunction'.

Protective Effect of Stachybotrys microspora Triprenyl Phenol-7on the Deposition of IgA to the Glomerular Mesangium in Nivalenol-induced IgA Nephropathy Using BALB/c Mice

Activators of tissue proteolysis including Stachybotrys microspora triprenyl phenol (SMTP)-7 are a new class of agents that are expected to be effective for amelioration of chronic tissue destructive diseases. The present study was performed to examine whether SMTP-7 is effective for the amelioration or protection of early-stage IgA nephropathy (IgAN) induced by nivalenol (NIV) in female BALB/c mice. In Experiment 1, mice were administered NIV at 24 ppm in diet for 8 weeks, and during the NIV treatment, they were intraperitoneally injected with SMTP-7 (10 mg/kg) three times a week. In Experiment 2, mice were injected similarly with SMTP-7 during the last 4 weeks of a 16-week NIV treatment. Immunofluorescence analysis revealed an inhibitory effect of SMTP-7 on the glomerular deposition of IgA in Experiment 1; however, it was ineffective in Experiment 2. On the other hand, SMTP-7 did not affect the serum concentration of IgA in both experiments. These results suggest that SMTP-7 has a potential to decrease the progression of IgAN induced by NIV through inhibition of local accumulation of IgA in the glomerular mesangium, while it was ineffective for suppression of IgA production. On the other hand, SMTP-7 was found to be ineffective for already deposited IgA, suggesting that SMTP-7 may not be effective for ameliorating advanced IgAN.

Structure activity relationship studies of natural product chemokine receptor CCR5 antagonist anibamine toward the development of novel anti prostate cancer agents

Recent studies have indicated that the CCR5 chemokine receptor may be a potential target for treating prostate cancer. Thus, development of CCR5 antagonists may provide novel prostate cancer therapy. Anibamine, a novel pyridine quaternary alkaloid isolated from Aniba sp., was found to effectively compete with (125)I-gp120 in binding to the chemokine receptor CCR5, with an IC(50) = 1 μM. Anibamine is the first natural product reported as a CCR5 antagonist, and thus provides a novel structural skeleton unique from other lead compounds that have generally been identified from high-throughput screening efforts. In order to refine the lead compound's structure and improve the therapeutic index of anibamine derivatives as potential anti prostate cancer agents, the approach of "deconstruction-reconstruction-elaboration" was applied in the structure-activity relationship studies of this work. Here, we report the design, syntheses and anti prostate cancer activities of anibamine and 17 analogues. The results from the in vitro and in vivo studies described here show that this class of compounds has potential to provide novel leads as anti prostate cancer agents.

The potential role of anibamine, a natural product CCR5 antagonist, and its analogues as leads toward development of anti-ovarian cancer agents

Chemokines and their receptors play important roles in the development of primary tumors and their metastases. Particularly CC chemokine receptor 5 (CCR5) and its ligand CC chemokine ligand 5 (CCL5/RANTES) seem to be critical in proliferation and invasion of ovarian cancer, the leading cause of death from gynecological malignancies in the United States. Anibamine, the first natural product CCR5 antagonist, and its analogues were examined for their effects on proliferation of the OVCAR-3 ovarian cancer cells in order to validate their candidacy as leads to develop novel anti-ovarian cancer agents. Acting as CCR5 antagonists, anibamine and its analogues significantly suppressed CCL5-induced intracellular Ca(2+) flux. The compounds also inhibited the proliferation of OVCAR-3 at micromolar to submicromolar range. Moreover, anibamine and several analogues did not show significant cytotoxicity in NIH 3T3 cells at concentrations up to 20μM. Based on these results, anibamine and one of its synthetic analogues were defined as potential leads to develop novel agents against ovarian cancer.

On the dual roles and polarized phenotypes of neutrophils in tumor development and progression

Inconsistencies plague our understanding of the role of neutrophils in cancer and the literature provides evidence for a duality in neutrophil activity on the outcome of cancer. Here, the different effects of neutrophils during the multiple subprocesses of cancer development and progression are overviewed, in order to gain insight into the features of both antitumoral and protumoral tumor-associated neutrophils (TAN). Neutrophils can counteract the progression of malignancies through tumor cytotoxicity, tumor rejection and enhancement of antitumoral immune memory. These cells have recently been phenotypically denominated N1 neutrophils. Recent studies indicate that cytokines, such as TGF-β and IFN-β, are involved in directing neutrophil polarization by the tumor microenvironment. With the opposite polarity, N2 neutrophils may be detrimental for the host and beneficial for tumor growth, invasion and metastasis, e.g. through proteolysis of extracellullar matrix components, promotion of angiogenesis and mediation of immunosuppression.

The natural product CCR5 antagonist anibamine and its analogs as anti-prostate cancer agents

Prostate cancer is a leading cause of death among males in the United States. As the chemokine receptor CCR5 is over-expressed in more aggressive forms of prostate cancer, and is also a critical receptor in inflammation, chemokine receptor CCR5 antagonists could potentially act as anti-prostate cancer agents. Anibamine, a natural product CCR5 antagonist, provides a unique molecular scaffold for the generation of novel analogs with possible anti-prostate cancer activity. A series of analogs of anibamine were designed, synthesized and tested against several prostate cancer cell lines. The analogs all acted as CCR5 antagonists at micromolar range affinity to the receptor while their anti-proliferative activity varied depending on the cell line type and their chemical structural properties. Further basal cytotoxicity characterization on these compounds indicated some of them may be suitable for in vivo studies.

Anibamine, a natural product CCR5 antagonist, as a novel lead for the development of anti-prostate cancer agents

Accumulating evidence indicates that the chemokine receptor CCR5 and the chemokine CCL5 may be involved in the proliferation and metastasis of prostate cancer. Consequently, chemokine receptor CCR5 antagonists could potentially act as anti-prostate cancer agents. As the first natural product CCR5 antagonist, anibamine provides a novel chemical structural skeleton compared with other known antagonists identified through high-throughput screening. Our studies demonstrate that anibamine produces significant inhibition of prostate cancer cell proliferation at micromolar to submicromolar concentrations as well as suppressing adhesion and invasion of the highly metastatic M12 prostate cancer cell line. Preliminary in vivo studies indicate that anibamine also inhibits prostate tumor growth in mice. These findings indicate that anibamine may prove to be a novel lead compound for the development of prostate cancer therapeutic agents.

Chemokines and bone remodeling

Bone remodeling is characterized by spatial and temporal coupling of bone resorption and formation and is necessary for skeletal growth and normal bone structure maintenance. Imbalance of this process is related to metabolic bone disorders such as osteoporosis or rheumatoid arthritis. For this reason, bone remodeling is under the control of several local and systemic factors, including molecules of the immune system. The importance of the interplay of both the skeletal and immune systems is reflected by the emerging interdisciplinary research field, called osteoimmunology, focused on common aspects of osteology and immunology. This review focuses on the role of inflammatory mediators, such as cytokines in bone remodeling and, in particular, a subfamily of chemotactic cytokines or chemokines which are involved not only in several aspects of physiological bone remodeling but also in pathological bone disorders, such as rheumatoid arthritis or osteoporosis. Understanding the role of inflammation and chemokines will provide new insights for the treatment of diseases affecting both skeletal and immune systems, by the development of new therapeutic strategies targeting common inflammatory mediators.

Tumor versus tumor-associated macrophages: how hot is the link?

One of the functions of macrophages is to provide a defense mechanism against tumor cells. In contrast, tumor-associated macrophages (TAMs), which represent the major inflammatory component of the stroma of many tumors, are associated with tumor progression and metastasis. TAMs, in contrast with normal macrophages, exhibit the M2 phenotype, and thereby exhibit pro-tumoral functions, including angiogenesis and matrix remodeling. This review will discuss the role of TAMs in tumor progression and provide an overview of their significant part in tumor metastasis and angiogenesis.

Stachybotrydial selectively enhances fibrin binding and activation of Glu-plasminogen

Stachybotrydial, a triprenyl phenol metabolite from a fungus, has a plasminogen modulator activity selective to Glu-plasminogen. Stachybotrydial enhanced fibrin binding and activation of Glu-plasminogen (2- to 4-fold enhancement at 60-120 microM) but not of Lys-plasminogen. Approximately 1.2-1.6 moles of [3H]stachybotrydial bound to Glu-plasminogen to exert such effects. The selective modulation of the Glu-plasminogen function by stachybotrydial may be related to alteration of its conformational status.

Matrix metalloproteinase inhibitors as therapy for inflammatory and vascular diseases

Matrix metalloproteinases (MMPs) have outgrown the field of extracellular-matrix biology and have progressed towards being important regulatory molecules in cancer and inflammation. This rise in status was accompanied by the development of various classes of inhibitors. Although clinical trials with synthetic inhibitors for the treatment of cancer were disappointing, recent data indicate that the use of selective inhibitors might lead to new therapies for acute and chronic inflammatory and vascular diseases. In this Review, we compare the major classes of MMP inhibitors and advocate that future drug discovery should be based on crucial insights into the differential roles of specific MMPs in pathophysiology obtained with animal models, including knockout studies.

CEBPbeta, JunD and c-Jun contribute to the transcriptional activation of the metastasis-associated C4.4A gene

The glycosylphosphatidylinositol-anchored molecule C4.4A, which shares structural features with uPAR, is frequently expressed on carcinomas with upregulated expression during tumor progression. Moreover, rare expression on nontransformed epithelial cells is strongly increased during tissue remodeling, e.g., during wound healing. This strictly regulated expression prompted us to define transcriptional activation of the C4.4A gene. C4.4A transcription was analyzed in 2 syngenic rat tumor cell lines with low or high metastatic potential, respectively. Though genomic C4.4A DNA was present in both lines, C4.4A mRNA and transcription of a reporter construct containing the C4.4A promoter was only observed in the metastasizing subline. Deletions and point mutations in the C4.4A promoter-driven reporter construct revealed that activation of the TATA-less, GC-rich core promoter (-1 to -50 bp) does not suffice to initiate transcription that requires coactivation of a proximal response element (-71 to -88 bp) and can be further increased by more distal response elements (-89 to -133 bp). Mobility-shift and cotransfection studies showed that Sp3 binding enhances C4.4A transcription, whereas potential Sp1 binding sites were ineffective. C4.4A transcription essentially requires C/EBPbeta binding to a TRE/CCAAT composite element (-71 to -88 bp) as measured by ChIP assay. C4.4A transcription is strikingly enhanced by cotransfection with JunD or c-Jun, such that C4.4A is most strongly transcribed even in the C4.4A-negative tumor cell line after cotransfection with C/EBPbeta plus JunD or c-Jun. Thus, upregulation of C/EBPbeta during tumor progression and wound repair may well provide a sufficient trigger for transcription of the C4.4A gene.

Evaluation of serum procalcitonin and interleukin-6 levels as markers of liver metastasis

OBJECTIVES

Procalcitonin (PCT) and interleukin-6 (IL-6) are established markers of tissue inflammation and injury. The aim of the present study was to investigate the possible correlation of PCT and IL-6 with liver metastasis.

DESIGN AND METHODS

The study consisted of fifteen healthy controls (group A), twenty-one patients with solid tumors without metastases (group B), eleven patients with liver metastasis only (group C) and eleven patients with generalized metastatic disease (group D).

RESULTS

Serum PCT levels were significantly increased in group D compared to groups A (p<0.001) and B (p=0.004), but no difference was observed in PCT levels between groups C and B or C and D. IL-6 serum levels were markedly elevated in group C compared to group A (p<0.001) or to groups B (p<0.001) and D (p=0.02). A positive correlation was observed between PCT and IL-6 serum levels (r=0.357, p=0.019).

CONCLUSIONS

PCT levels are related to disease stage in cancer patients, whereas IL-6 concentration seems to be a more specific marker of liver metastasis.

Macrophage inflammatory protein (MIP)1alpha and MIP1beta differentially regulate release of inflammatory cytokines and generation of tumoricidal monocytes in malignancy

The C-C chemokines, macrophage inflammatory protein (MIP)1alpha and MIP1beta are potent chemoattractants for the monocytes, which form an important component of the stroma of tumor tissue and may regulate tumor growth and associated inflammation. We examined the role of MIP1alpha and MIP1beta in inducing the release of inflammatory cytokines and the generation of tumoricidal monocytes from the peripheral blood monocytes (PBM) of healthy women and patients with carcinoma of breast (CaBr). Interleukin-1 (IL-1) and tumor necrosis factor (TNF) alpha release by the PBM was markedly stimulated by MIP1alpha in CaBr patients, but only marginally so in healthy women. In contrast, MIP1beta stimulated the release of these cytokines by the PBM of healthy women, but failed to do so in CaBr patients. MIP1alpha, but not MIP1beta, synergized with LPS in inducing the release of IL-1 from the PBM of both healthy women and CaBr patients. Both MIP1alpha and MIP1beta augmented respiratory bursts in PBM and generated tumoricidal PBM that killed T24 cells, MIP1alpha being more effective in CaBr patients and MIP1beta in healthy women. IFN-gamma co-stimulated and IL-4 suppressed MIP1alpha and beta-induced cytotoxicity in PBM. The synergy of IFN-gamma was more marked with MIP1alpha than with MIP1beta. The differential effects of MIP1alpha and MIP1beta on the PBM of healthy women and CaBr patients co-related with the levels of expression of CCR1 and CCR5 in these monocytes. The expression of CCR5 was higher than that of CCR1 in the PBM of healthy women and the PBM of the CaBr patients showed overexpression of CCR1 and downregulation of CCR5.

Expression of chemokines and gelatinase B in sympathetic ophthalmia

PURPOSE

To examine the expression of gelatinase B (matrix metalloproteinase-9) and the chemokines monocyte chemotactic protein-1 (CCL2/MCP-1) and stromal cell-derived factor-1 (CXCL12/SDF-1) in sympathetic ophthalmia (SO).

METHODS

Five enucleated exciting eyes with a clinical diagnosis and typical histopathological findings of SO were studied by immunohistochemical techniques using a panel of monoclonal antibodies directed against gelatinase B, MCP-1, and SDF-1. In addition, a panel of monoclonal and polyclonal antibodies was used to characterize the composition of the inflammatory infiltrate.

RESULTS

In all cases, the extensive uveal inflammatory infiltrate was organized as a diffuse infiltrate and as large granulomas consisting of epithelioid cells and multinucleated giant cells. CD20(+) B lymphocytes predominated in the diffuse infiltrate and CD3(+) T lymphocytes were few. The monocyte/macrophage marker CD68 was expressed in scattered inflammatory mononuclear cells and within granulomas and Dalen-Fuchs nodules. Most of the inflammatory cells were HLA-DR(+). Immunoreactivity for gelatinase B, MCP-1, and SDF-1 was observed in cells within granulomas and in scattered epithelioid cells. Immunoreactivity for MCP-1 was noted in retinal pigment epithelial cells. Endothelial cells of choriocapillaries showed weak immunoreactivity for SDF-1.

CONCLUSIONS

Gelatinase B, MCP-1, and SDF-1 might have a pathogenic role in the recruitment of leucocytes into the eye in SO.

Adrenomedullin enhances invasion by trophoblast cell lines

We have tested the hypothesis that adrenomedullin (ADM), a multifunctional peptide hormone, works as a trophoblast proinvasion factor. Our results showed that ADM receptor components-the mRNA and proteins of calcitonin receptor-like receptor (CALCRL) and receptor activity modifying proteins (RAMPs)-were expressed by human choriocarcinoma JAr cells and first-trimester cytotrophoblast HTR-8/SV neo cells. ADM stimulates both JAr and HTR-8/SV neo cell proliferation. The invasion capabilities of JAr cells and HTR-8/SV neo cells were also enhanced by ADM, and this was associated with increased gelatinolytic activity and reduced plasminogen activator inhibitor-1 mRNA expression (SERPINE1). Our data support the notion that ADM may be involved in the human implantation process via regulating trophoblast proliferation and differentiation.

Bacillolysin MA, a Novel Bacterial Metalloproteinase That Produces Angiostatin-like Fragments from Plasminogen and Activates Protease Zymogens in the Coagulation and Fibrinolysis Systems

We isolated a novel protease that converts plasminogen to angiostatin-like fragments (BL-angiostatins) from a culture of Bacillus megaterium A9542 through a single-step chromatography on CM-cellulose. The protease, designated bacillolysin MA (BL-MA), belongs to a family of neutral metalloproteinases based on the nucleotide sequence of its gene. At an enzyme:substrate ratio of 1:540, BL-MA cleaved human plasminogen mainly at Ser441-Val442 to form BL-angiostatin and miniplasminogen with a K(m) of 3.0 +/- 0.8 microM and a k(cat) of 0.70 +/- 0.09 s(-1). The resulting BL-angiostatins inhibited the proliferation, migration, and tube formation of vascular endothelial cells at concentrations of 1-10 microg/ml. Although BL-MA failed to activate plasminogen, it increased urokinase-catalyzed activation of plasminogen caused by production of miniplasminogen, which is highly susceptible to activation. In addition, BL-MA was active in converting prourokinase, prothrombin, coagulation factor X, and protein C to their active forms. BL-MA enhanced both the clotting of human plasma and clot dissolution in the presence of prourokinase. Thus, BL-MA affects blood coagulation and fibrinolysis systems and can be used to produce angiostatin-like plasminogen fragments and active serine proteases of human plasma.

Proteolytic-antiproteolytic balance and its regulation in carcinogenesis

Cancer development is essentially a tissue remodeling process in which normal tissue is substituted with cancer tissue. A crucial role in this process is attributed to proteolytic degradation of the extracellular matrix (ECM). Degradation of ECM is initiated by proteases, secreted by different cell types, participating in tumor cell invasion and increased expression or activity of every known class of proteases (metallo-, serine-, aspartyl-, and cysteine) has been linked to malignancy and invasion of tumor cells. Proteolytic enzymes can act directly by degrading ECM or indirectly by activating other proteases, which then degrade the ECM. They act in a determined order, resulting from the order of their activation. When proteases exert their action on other proteases, the end result is a cascade leading to proteolysis. Presumable order of events in this complicated cascade is that aspartyl protease (cathepsin D) activates cysteine proteases (e.g., cathepsin B) that can activate pro-uPA. Then active uPA can convert plasminogen into plasmin. Cathepsin B as well as plasmin are capable of degrading several components of tumor stroma and may activate zymogens of matrix metalloproteinases, the main family of ECM degrading proteases. The activities of these proteases are regulated by a complex array of activators, inhibitors and cellular receptors. In physiological conditions the balance exists between proteases and their inhibitors. Proteolytic-antiproteolytic balance may be of major significance in the cancer development. One of the reasons for such a situation is enhanced generation of free radicals observed in many pathological states. Free radicals react with main cellular components like proteins and lipids and in this way modify proteolytic-antiproteolytic balance and enable penetration damaging cellular membrane. All these lead to enhancement of proteolysis and destruction of ECM proteins and in consequence to invasion and metastasis.

Chemokine-protease interactions in cancer

Solid tumour and leukemic cells expressing chemokine receptors, metastasize to chemokine-secreting organs. Chemokines indirectly affect tumour development by attracting immunocompetent cells with pro- or anti-tumoral activities. Various membrane-associated and soluble proteases selectively cleave specific chemokines. Precursor plasma chemokines (CXCL7, CCL14) need to be proteolytically processed to obtain receptor affinity. Angiogenic CXC chemokines (CXCL1, CXCL8) have increased CXCR1/CXCR2 affinity after limited NH2-terminal processing, whereas truncated angiostatic chemokines (CXCL10) show lower CXCR3 affinity without loss of angiostatic potential. NH2-terminally cleaved monocyte chemotactic proteins (CCL2, CCL7, CCL8) have impaired capacity to attract tumour-associated macrophages and function as receptor antagonists for intact CC chemokines. Migration of Th1/CCR5+ and Th2/CCR4+ effector lymphocytes toward CCR5 (CCL5, CCL3L1) and CCR4 (CCL22) ligands is affected by cleavage. Although proteolytical processing of chemokines is well studied in vitro, the direct or indirect effects on tumour invasion and metastasis are only poorly evaluated.

Impact of tumor-derived CCL2 on T cell effector function

To study the effects of tumor-derived monocyte chemoattractant protein-1 (MCP-1, CCL2) on the anti-tumor immune response we used the 4T1 murine mammary carcinoma which constitutively expresses CCL2. We generated 4T1 that do not express detectable levels of CCL2 and found that the T cell response to the tumors were altered. Lymph nodes draining the CCL2- tumor contained CD62Llo cells that produced greater levels of INF-gamma in response to the tumor than CD62Llo cells from lymph nodes draining a tumor that produced CCL2. Moreover, exposure of splenic T cells to recombinant CCL2 in vitro decreased the ability of the T cells to produce IFN-gamma. However, despite the enhanced effector function evident in the absence of CCL2, vaccination/challenge experiments failed to reveal an increase in immunogenicity of the CCL2 null cells relative to the CCL2+ cells. Collectively, these data indicate that tumor-derived CCL2 could decrease T cell effector function, yet not the overall immunogenicity of the tumor.

Chemokines and gelatinases in the aqueous humor of patients with active uveitis

PURPOSE

To investigate the involvement of the chemokines CXCL10/IP-10, CXCL11/I-TAC, CXCL8/1L-8, CXCL6/GCP-2, CCL3/MIP-1alpha, and CCL18/PARC, and gelatinases A and B in uveitis.

DESIGN

Prospective, experimental, case-control study.

METHODS

Aqueous humor samples from 30 patients with active uveitis, and 14 control patients and paired serum samples were assayed for chemokines with specific enzyme-linked immunosorbent assays (ELISAs) and for gelatinase levels by quantitative zymography.

RESULTS

In control AH, none of the chemokines was detected. Gelatinase A was detected in all samples, and gelatinase B was detected in only one sample. In patients with uveitis, IP-10 was detected in all AH samples, whereas I-TAC, IL-8, GCP-2, MIP-1alpha, and PARC were detected in three, 16, six, two, and 12 samples, respectively. IP-10 levels were significantly higher in AH samples than those of serum (P =.006). Gelatinase A was detected in 29 AH samples and gelatinase B was detected in 26 samples. Gelatinase A levels were significantly higher in AH samples from patients than those of controls (P <.0001). In 11 AH samples, gelatinase B was detected in complex with lipocalin (NGAL). Disease activity correlated significantly with the levels of IP-10 (r =.627; P <.0001), gelatinase A (r =.508; P =.002), gelatinase B (r =.685; P <.0001), and NGAL-gelatinase B complex (r =.595; P <.0001).

CONCLUSIONS

These data suggest a pathogenic role of the T lymphocyte chemoattractant IP-10 and gelatinases in the recruitment and activity of T cells into the eye in patients with uveitis and in the pathogenesis of uveitis.

Interleukin-6/soluble interleukin-6 receptor signaling attenuates proliferation and invasion, and induces morphological changes of a newly established pleomorphic malignant fibrous histiocytoma cell line

Pleomorphic malignant fibrous histiocytoma (MFH) is occasionally associated with inflammatory paraneoplastic syndrome (PNS). Recently, we reported that interleukin (IL)-6, one of the candidate cytokines, which induces such systemic inflammatory reaction, may be a tumor-associated factor involved in the pathogenesis and its clinical manifestations of MFH. In the local microenvironment, tumor-induced inflammatory reaction may play a role favoring tumor progression. To clarify the biological relevance of IL-6 in MFH, we established a human MFH cell line, named MIPS-2, derived from a resected specimen of a patient presenting with PNS. In this patient, the serum IL-6 level ran parallel to the disease course: elevated serum IL-6 concentration normalized immediately after radical surgery, and re-elevation occurred on tumor recurrence. MIPS-2 presented pleomorphic appearance, severe nuclear abnormalities with prominent nucleoli, and tumorigenesis in nude mice. MIPS-2 expressed IL-6, IL-6 receptor (IL-6R), and glycoprotein 130 (gp130) but lacked the soluble form of IL-6R (sIL-6R), as determined by flow cytometry and reverse transcriptase-polymerase chain reaction analyses. Stimulation of MIPS-2 with IL-6 combined with exogenous sIL-6R induced phosphorylation of both signal transducer and activator of transcription 3 (STAT3) and mitogen-activated protein kinase (MAPK), decreased cell proliferation, attenuated invasion, and induced morphological changes. Collectively, these data suggested that the IL-6/sIL-6R signaling pathway plays a pivotal role for proliferation, invasion, and morphology of MFH via STAT3 and MAPK pathway as autocrine and/or paracrine manner, and proposed the therapeutic potential for the use of both anti-growth factor and proinflammatory cytokine-targeting strategies to combat devastating MFH.

Reduction of excitotoxicity and associated leukocyte recruitment by a broad‐spectrum matrix metalloproteinase inhibitor

An important step in the cascade leading to neuronal cell death is degradation of laminin and other components of the brain extracellular matrix by microglia-derived proteases. Excitotoxic cell death of murine hippocampal neurones in vivo can be prevented by inhibitors of tissue plasminogen activator (tPA) or by inhibitors of plasmin. Plasmin is a potent activator of the matrix metalloproteinases (MMPs), which are made by resident and recruited leukocytes following CNS injury. In this study, we show, using Taqman RT-PCR, that MMP mRNAs, but not other calcium-dependent proteases such as calpain mRNAs, are acutely up-regulated after an excitotoxic challenge in vivo. alpha(2)-antiplasmin or BB-3103, a broad-spectrum inhibitor of the MMPs, co-injected with kainic acid into the striatum, inhibits excitotoxic cell death in the rat striatum, and reduces both the number of recruited macrophages and the size of the lesion. We also show that leukocyte populations differentially express MMPs, which may account, in part, for the expression profile we observe in the challenged brain. Our results show that inhibition of the MMPs in the rat will prevent kainic acid-induced cell death in the brain. These studies suggest that MMP inhibitors have therapeutic potential for use in stroke, and support the increasing evidence that microglial activation may contribute to neuronal cell death.

Identification of a carcinoembryonic antigen binding protein on monocytes

Tumor-associated monocyte/macrophage cells are important stromal components involved in tumor development. A protein on human monocyte is identified that binds to carcinoembryonic antigen (CEA), a glycoprotein overexpressed in colon tumors. This implicates a role for this protein in CEA processing and establishes a link between monocytes and colon tumor cells. In vitro uptake of 125I-labeled CEA with isolated monocytes showed time and temperature dependence. The binding of 125I-CEA was specific and saturable as it could be inhibited by an excess of unlabeled CEA. To identify the binding protein on monocyte, we used a radiolabeled photoactivable heterobifunctional crosslinking agent and demonstrated that CEA reacts with a 115kDa protein as determined by SDS-polyacrylamide gel electrophoresis and autoradiography. Treatment of human monocytes in vitro with CEA resulted in a several fold increase in the production of proinflammatory cytokines TNF-alpha, IL-1 beta, and IL-6 compared to untreated controls. Binding of CEA to the monocyte protein may have implications in colon tumorigenesis.

The fibroblast: sentinel cell and local immune modulator in tumor tissue

Development and progression of epithelial malignancies are frequently accompanied by complex phenotypic alterations of resident tissue fibroblasts. Some of these changes, such as myofibroblastic differentiation and an oncofetal extracellular matrix (ECM) expression profile, are also implicated in inflammation and tissue repair. Studies over the past decade revealed the relevance of reciprocal interactions between tumor cells and tumor-associated host fibroblasts (TAF) in the malignant process. In many tumors, a considerable fraction of the inflammatory infiltrate is located within the fibroblast- and ECM-rich stromal compartment. However, while fibroblasts are known as "sentinel cells" in various nonneoplastic diseases, where they often regulate the composition and function of recruited leucocytes, they are hardly considered active participants in the inflammatory host response in tumors. This article focuses on the functional impact of TAF on immune cells. The complex network of immune-modulating effects transduced by TAF and TAF-derived factors is highlighted, and recent reports that support the hypothesis that TAF are involved in the inflammatory response and immune suppression in tumors are reviewed. The role of TAF-dependent ECM remodeling and TAF-derived peptide growth factors, cytokines, and chemokines in the immune modulation is stressed and the idea of TAF as an important therapeutic target is emphasized.

Cytokine and cytokine receptor serum levels in adult bone sarcoma patients: Correlations with local tumor extent and prognosis

BACKGROUND AND OBJECTIVES

We analyzed the correlations between pretreatment serum levels of 11 cytokines and soluble cytokine receptors (interleukin 6 (IL-6); interleukin 8 (IL-8); interleukin 10 (IL-10); vascular endothelial growth factor (VEGF); basic fibroblast growth factor (bFGF); macrophage colony-stimulating factor (M-CSF); granulocyte colony-stimulating factor (G-CSF); interleukin 1 receptor antagonist (IL-1ra); sIL-2Ralpha; tumor necrosis factor receptor I (TNF RI), and TNF RII) with clinico-pathological features and survival of patients with bone sarcomas.

METHODS

Altogether, 72 patients with bone sarcomas without distant metastases before treatment (26 osteosarcomas-36%, 23 chondrosarcomas-32%, 13 Ewing's sarcomas/PNET-18%, 10 giant-cell tumors-14%), 22 patients with benign non-inflammatory bone tumors and 50 age-matched healthy controls were included into this prospective study.

RESULTS

Median serum levels of 9/11 cytokines, with the exception of sIL-2Ralpha and G-CSF, were significantly higher in sarcoma patients than in controls. Median serum levels of IL-6, IL-8, IL-1ra, TNF RI, and M-CSF were significantly higher in patients with bone sarcoma as compared to patients with benign bone tumors. In 45.9% of sarcoma patients, six or more cytokines and cytokine receptors, including those that are involved in bone destruction (e.g., IL-6 and IL-8) and bone formation (e.g., IL-1ra and TNFRI and TNFRII), were elevated in parallel. Serum levels of IL-6, IL-8, TNF RI, TNF RII, and VEGF correlated significantly with tumor size (<10 cm vs. >or=10 cm in diameter) and serum levels of IL-6, IL-8, TNF RI, and IL-1ra correlated significantly with local tumor extent (E2/4 vs. E5/6 according to the classification proposed by Spanier et al. 46). Moreover, serum levels of IL-1ra and IL-6 were significantly higher in patients with small tumors (<5 cm in diameter) infiltrating structures adjacent to the periosteum (E5/6) than in large tumors (>10 cm in diameter) but confined to the bone and periosteum (E < 4). The lowest median serum levels of 8/11 cytokines/cytokine receptors were found in patients with giant-cell tumors. In an univariate analysis, increased serum levels of IL-1ra, IL-6, IL-8, IL-10, sIL-2Ralpha, M-CSF, TNF RI, and TNF RII, the number of cytokines elevated, higher tumor grade, larger tumor size, greater local extent (E) and patients' age >35 years correlated with poor overall survival (OS) (P < 0.05). Similarly, high serum levels of IL-1ra, IL-6, TNF RI and TNF RII, tumor grade, tumor size, and tumor local extent (E) (P < 0.05) affected disease free survival (DFS) in univariate analysis. Multivariate analysis using Cox's proportional hazards model showed that high serum levels of IL-1ra (P = 0.039) and TNF RI (P = 0.048), the number of serum cytokines above normal cut-off values (0-1 vs. 2-5 vs. >or=6; P = 0.029), greater tumor local extent E (E2/4 vs. E5/6; P = 0.02) correlated significantly with shorter OS. Only E was found as an independent prognostic factor for DFS (P = 0.04).

CONCLUSIONS

These findings indicate that cytokines and soluble cytokine receptors, both physiologically involved in bone destruction and bone formation, have an essential role in the progression of malignant bone tumors.

Gelatinase B/MMP-9 and neutrophil collagenase/MMP-8 process the chemokines human GCP-2/CXCL6, ENA-78/CXCL5 and mouse GCP-2/LIX and modulate their physiological activities

On chemokine stimulation, leucocytes produce and secrete proteolytic enzymes for innate immune defence mechanisms. Some of these proteases modify the biological activity of the chemokines. For instance, neutrophils secrete gelatinase B (matrix metalloproteinase-9, MMP-9) and neutrophil collagenase (MMP-8) after stimulation with interleukin-8/CXCL8 (IL-8). Gelatinase B cleaves and potentiates IL-8, generating a positive feedback. Here, we extend these findings and compare the processing of the CXC chemokines human and mouse granulocyte chemotactic protein-2/CXCL6 (GCP-2) and the closely related human epithelial-cell derived neutrophil activating peptide-78/CXCL5 (ENA-78) with that of human IL-8. Human GCP-2 and ENA-78 are cleaved by gelatinase B at similar rates to IL-8. In addition, GCP-2 is cleaved by neutrophil collagenase, but at a lower rate. The cleavage of GCP-2 is exclusively N-terminal and does not result in any change in biological activity. In contrast, ENA-78 is cleaved by gelatinase B at eight positions at various rates, finally generating inactive fragments. Physiologically, sequential cleavage of ENA-78 may result in early potentiation and later in inactivation of the chemokine. Remarkably, in the mouse, which lacks IL-8 which is replaced by GCP-2/LIX as the most potent neutrophil activating chemokine, N-terminal clipping and twofold potentiation by gelatinase B was also observed. In addition to the similarities in the potentiation of IL-8 in humans and GCP-2 in mice, the conversion of mouse GCP-2/LIX by mouse gelatinase B is the fastest for any combination of chemokines and MMPs so far reported. This rapid conversion was also performed by crude neutrophil granule secretion under physiological conditions, extending the relevance of this proteolytic cleavage to the in vivo situation.

Potential of p38 MAP kinase inhibitors in the treatment of cancer

The involvement of chronic inflammation in tumor development and progression is reviewed. Based on the natural history of certain diseases and epidemiology studies, a strong association has been established between particular chronic inflammatory conditions and eventual tumor appearance. Solid tumors require a stroma for their growth and recruit macrophages to synthesize essential growth and angiogenic factors that they do not have the capacity to produce. The microenvironment of the local host tissue appears to be an active participant in exchanging cytokines and enzymes with tumor cells that modify the local extracellular matrix, stimulate migration, and promote tumor angiogenesis, proliferation and survival. The role of p38 MAP kinase as a therapeutic target for treating cancer is discussed.

Chemokines and antitumor immunity: walking the tightrope

Chemokines play an important role in the generation of the immune system and in virtually every aspect of an immune response. The role of chemokines in antitumor immunity has been less straightforward to discern. A dichotomy exists in the field. One area of research has focused on the impact of tumor-derived chemokines, implicating them in everything from metastases to immune suppression. Another area of research has been dedicated to the introduction of chemokines into tumor cells in order to facilitate immune cell recruitment. In this review these two areas of investigation will be explored.

Antagonistic effect of NK cells on alternatively activated monocytes: a contribution of NK cells to CTL generation

Natural killer (NK) cells fulfill essential accessory functions for the priming of antigen-specific cytotoxic T lymphocytes (CTLs). On the basis of a NKG2D-ligand-positive tumor model, we obtained results implicating NK-mediated regulatory as well as NK-mediated cytolytic activities in the initiation and persistence of CTL activity. Indeed, CD8(+) T-cell-dependent tumor rejection requires NK cell function in vivo, because tumors will progress both on depletion of NK cells or in the absence of optimal NK activity. Here we provide evidence that the absence of NK cells during subcutaneous tumor growth will abrogate generation of antitumor CTL responses and that this process can be linked to the expansion of alternatively activated monocytes. Indeed, our in vitro studies demonstrate that in splenic cultures from NK-deficient tumor-bearing mice, lack of type 1-associated cytokines correlates with the presence of type 2 (alternatively activated) monocytes and the production of type 2 cytokines. Furthermore, these type 2 monocyte-containing splenic adherent populations potently suppress subsequent memory CTL restimulation. We evaluated the role of NK lytic effector functions in the efficient switch of the immune system toward classical (type 1) activation by including differentially activated monocytic populations as targets in cytotoxicity assays. The results indicate that the accessory function of NK cells depends partially on the ability of activated NK cells to preferentially engage type 2 antigen-presenting cells. Thus, when the immune system tends to be type 2 oriented, NK cells can drive an efficient type 2 --> type 1 switch in the population of antigen-presenting cells to provide signaling for the generation of CTLs.