Prostate Cancer Stem Cells: Biology and Treatment Implications.

Stem cells differentiate into mature organ/tissue-specific cells at a steady pace under normal conditions, but their growth can be accelerated during the process of tissue healing or in the context of certain diseases. It is postulated that the proliferation and growth of carcinomas are sustained by the presence of a vital cellular compartment resembling stem cells residing in normal tissues: 'stem-like cancer cells' or cancer stem cells (CSCs). Mutations in prostate stem cells can lead to the formation of prostate cancer. Prostate CSCs (PCSCs) have been identified and partially characterized. These express surface markers include CD44, CD133, integrin α2ß1, and pluripotency factors like OCT4, NANOG, and SOX2. Several signaling pathways are also over-activated, including Notch, PTEN/Akt/PI3K, RAS-RAF-MEK-ERK and HH. Moreover, PCSCs appear to induce resistance to radiotherapy and chemotherapy, while their presence has been linked to aggressive cancer behavior and higher relapse rates. The development of treatment policies to target PCSCs in tumors is appealing as radiotherapy and chemotherapy, through cancer cell killing, trigger tumor repopulation via activated stem cells. Thus, blocking this reactive stem cell mobilization may facilitate a positive outcome through cytotoxic treatment.

REDD1/Autophagy Pathway Is Associated with Neutrophil-Driven IL-1ß Inflammatory Response in Active Ulcerative Colitis.

Infiltration of neutrophils into colonic mucosa has been associated with the severity of ulcerative colitis (UC). We investigated the effect of disease microenvironment on the release of neutrophil extracellular traps (NETs) as well as the involved mechanisms in NETosis and whether certain NET proteins are correlated with disease phenotype. Peripheral blood neutrophils, sera, and colonic tissue were collected from treatment-naive and mesalazine-treated patients with active UC, treatment-naive patients with active Crohn's disease, patients suffering from infectious colitis, or healthy individuals (controls). Analysis of colonic biopsy specimens and peripheral blood neutrophils for the presence of NET-related markers using immunofluorescence confocal microscopy, ELISA, immunoblotting, flow cytometry, and quantitative PCR were performed. In vitro cell and tissue culture systems were further deployed. The local inflammatory response in colon in UC, but not Crohn's disease, is characterized by the presence of NETs carrying bioactive IL-1ß and thrombogenic tissue factor. The inflammatory environment of UC is able to induce neutrophil activation, IL-1ß expression, and NET release, as shown both ex vivo and in vitro. REDD1 expression, as a mediator linking inflammation, autophagy, and NET release, was also specifically associated with the inflammatory response of UC. We show that neutrophil expression of REDD1 in colon tissue and the presence of IL-1ß in neutrophils/NETs provide candidate biomarkers for the differential diagnosis of inflammatory colitis and possible targets for the treatment of UC, suggesting that UC shares common features with autoinflammatory disorders.

REDD1/autophagy pathway promotes thromboinflammation and fibrosis in human systemic lupus erythematosus (SLE) through NETs decorated with tissue factor (TF) and interleukin-17A (IL-17A).

OBJECTIVES: The release of neutrophil extracellular traps (NETs) represents a novel neutrophil effector function in systemic lupus erythematosus (SLE) pathogenesis. However, the molecular mechanism underlying NET release and how NETs mediate end-organ injury in SLE remain elusive. METHODS: NET formation and NET-related proteins were assessed in the peripheral blood and biopsies from discoid lupus and proliferative nephritis, using immunofluorescence, immunoblotting, quantitative PCR and ELISA. Autophagy was assessed by immunofluorescence and immunoblotting. The functional effects of NETs in vitro were assessed in a primary fibroblast culture. RESULTS: Neutrophils from patients with active SLE exhibited increased basal autophagy levels leading to enhanced NET release, which was inhibited in vitro by hydroxychloroquine. NETosis in SLE neutrophils correlated with increased expression of the stress-response protein REDD1. Endothelin-1 (ET-1) and hypoxia-inducible factor-1α (HIF-1α) were key mediators of REDD1-driven NETs as demonstrated by their inhibition with bosentan and L-ascorbic acid, respectively. SLE NETs were decorated with tissue factor (TF) and interleukin-17A (IL-17A), which promoted thrombin generation and the fibrotic potential of cultured skin fibroblasts. Notably, TF-bearing and IL-17A-bearing NETs were abundant in discoid skin lesions and in the glomerular and tubulointerstitial compartment of proliferative nephritis biopsy specimens. CONCLUSIONS: Our data suggest the involvement of REDD1/autophagy/NET axis in end-organ injury and fibrosis in SLE, a likely candidate for repositioning of existing drugs for SLE therapy. Autophagy-mediated release of TF-bearing and IL-17A-bearing NETs provides a link between thromboinflammation and fibrosis in SLE and may account for the salutary effects of hydroxychloroquine.

Angiogenic regeneration defines loco-regional recurrence following pre-operative radio-chemotherapy for rectal cancer: a pilot study.

Previous studies from our group have brought forward the concept of angiogenic regeneration during radiotherapy (RT), as a major cause of RT failure. This process was examined herein in rectal cancer patients undergoing preoperative chemo-radiotherapy. Out of 25 patients with stage II/III rectal adenocarcinoma, 15 had incomplete response (pIR) after preoperative chemo-radiotherapy. The MIB1 proliferation index, the vascular density (VD) assessed with the anti-CD31 antibody and the Hypoxia Inducible Factor HIF1α was assessed. High VD before RT was related with poor local relapse free survival LRFS (p = 0.04), in cases with pIR. Pre-RT values of MIB1 and of HIF1α were not related with LRFS. High MIB1 index and intensification of VD beyond pre-treatment levels in post-RT samples, features indicative of angiogenic regeneration, defined poor LRFS (p = 0.04 and p = 0.0008, respectively). Angiogenic regeneration is strongly related to failure of RT and surgery to control loco-regional disease in rectal cancer patients. Addition of anti-angiogenic agents in the preoperative chemo-radiotherapy regimens may prove beneficial in subgroups of patients.

Interferon lambda1/IL-29 and inorganic polyphosphate are novel regulators of neutrophil-driven thromboinflammation.

Neutrophils and neutrophil-released meshwork structures termed neutrophil extracellular traps (NETs) are major mediators of thromboinflammation and emerging targets for therapy, yet the mechanisms and pathways that control the role of neutrophils in thromboinflammation remain poorly understood. Here, we explored the role of IFN-λ1/IL-29, a major antiviral cytokine recently shown to suppress the neutrophil migratory capacity, in prothrombotic and proNETotic functions of neutrophils. In an ex vivo human experimental setting of acute ST-segment elevation myocardial infarction (STEMI), we show that IFN-λ1/IL-29 hinders NET release and diminishes the amount of cytoplasmic TF in neutrophils. Since platelet-neutrophil interaction plays a major role in NET-induced thromboinflammation, we further studied how IFN-λ1/IL-29 may interrupt this interaction. In this context, we identified inorganic polyphosphate (polyP) as a platelet-derived NET inducer in STEMI. In arterial STEMI thrombi, polyP was present in platelets and in close proximity to NET remnants. PolyP release from activated platelets was dependent on thrombin present in infarcted artery plasma, resulting in NET formation by promoting mTOR inhibition and autophagy induction. The effect of polyP on mTOR inhibition was counteracted by IFN-λ1/IL-29 treatment, leading to inhibition of NET formation. Consistently, we show in an in vivo model of FeCl3 -induced arterial thrombosis that IFN-λ2/IL-28A exerts strong antithrombotic potential. Taken together, these findings reveal a novel function of IFN-λ1/IL-29 in the suppression of thromboinflammation. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Differential effect of hypoxia and acidity on lung cancer cell and fibroblast metabolism.

This study examined the metabolic response of lung cancer cells and normal lung fibroblasts to hypoxia and acidity. GLUT1 and HXKII mRNA/protein expression was up-regulated under hypoxia in the MRC5 fibroblasts and in the A549 and H1299 lung cancer cell lines, indicating intensified glucose absorption and glycolysis. Under hypoxia, the LDHA mRNA and LDH5 protein levels increased in the cancer cells but not in the fibroblasts. Acidity suppressed the above-mentioned hypoxia effect. PDH-kinase-1 (PDK1 mRNA and protein) and inactive phosphorylated-PDH protein levels were induced under hypoxia in the cancer cells, whereas these were reduced in the MRC5 lung fibroblasts. In human tissue sections, the prevalent expression patterns supported the contrasting metabolic behavior of cancer cells vs. tumor fibroblasts. The monocarboxylate/lactate transporter 1 (MCT1) was up-regulated in all the cell lines under hypoxic conditions, but it was suppressed under acidic conditions. The mitochondrial DNA (mtDNA) content per cell decreased significantly in the A549 cancer cell line under hypoxia, but it increased in the MRC5 fibroblasts. Taking into account these findings, we suggest that, under hypoxia, cancer cells intensify the anaerobic direction in glycolysis, while normal fibroblasts prefer to seek energy by intensifying the aerobic use of the available oxygen.

Expression of enzymes related to glucose metabolism in non-small cell lung cancer and prognosis.

Purpose/Aim: Cancer cells are addicted to glycolytic anaerobic pathways, in presence or in absence of a functional Krebs' cycle (phenomenon Warburg). This metabolic predilection relies on both extracellular (impaired vascularization and oxygenation) and intracellular (oncogenic activation of genes) causes. MATERIALS AND METHODS: We investigated the expression and prognostic relevance of enzymes involved in the glucose absorption and metabolism, monocarboxylate transporter (MCT) expression, MCT1 and MCT2, pentose pathway (Glucose-6-phospahte dehydrogenase G6PD), glycogene synthesis (glycogene synthase GYS1), glycolysis (Hexokinase HXKII, phosphofructokinase PFK1, fructose biphosphate aldolase), fate of pyruvate (pyruvate dehydrogenase PDH, phosphorylated pPDH, PDH kinase PDK1, lactate dehydrogenase LDH5 and LDH1) and key Kreb's cycle enzymes (citrate synthase CSynth and isocitrate dehydrogenase IDH). RESULTS: A strong overexpression of the above enzymes/proteins was noted in a varying percentage of cases examined. An interesting significant correlation between the enzymes involved in glycolysis and with the LDH5 was noted. Adenocarcinomas expressed higher levels of GLUT1 and MCT2 compared to other subtypes. Stage (p = 0.0001), aldolase (p = 0.004), LDH5 (p = 0.008), GLUT2 (p = 0.008), MCT2 (p = 0.009), GSYS1 (p = 0.04), and GLUT1 (p = 0.05) were significantly related with poor disease specific overall survival. In multivariate analysis stage (p = 0.001), LDH5 (p = 0.04), pPDH (p = 0.04), and aldolase (p = 0.04) were independent prognostic variables. CONCLUSION: It is concluded that an orchestrated activation of glucose absorption and metabolism towards anaerobic pathways characterize the majority of NSCLC, and this phenotype is strongly linked with an aggressive clinical behavior. This glycolytic addiction of lung cancer cell is revealed as a key therapeutic target.

Expression of functional tissue factor by neutrophil extracellular traps in culprit artery of acute myocardial infarction.

AIMS: Neutrophil extracellular traps (NETs) are chromatin filaments released by activated polymorphonuclear neutrophils (PMNs) and decorated with granule proteins with various properties. Several lines of evidence implicate NETs in thrombosis. The functional significance and the in vivo relevance of NETs during atherothrombosis in humans have not been addressed until now. METHODS AND RESULTS: Selective sampling of thrombotic material and surrounding blood from the infarct-related coronary artery (IRA) and the non-IRA was performed during primary percutaneous revascularization in 18 patients with ST-segment elevation acute myocardial infarction (STEMI). Thrombi isolated from IRA contained PMNs and NETs decorated with tissue factor (TF). Although TF was expressed intracellularly in circulating PMNs of STEMI patients, active TF was specifically exposed by NETs obtained from the site of plaque rupture. Treatment of NET structures with DNase I abolished TF functionality measurement. In vitro treatment of control PMNs with plasma obtained from IRA and non-IRA was further shown to induce intracellular up-regulation of TF but not NET formation. A second step consisting of the interaction between PMNs and thrombin-activated platelets was required for NET generation and subsequent TF exposure. CONCLUSION: The interaction of thrombin-activated platelets with PMNs at the site of plaque rupture during acute STEMI results in local NET formation and delivery of active TF. The notion that NETs represent a mechanism by which PMNs release thrombogenic signals during atherothrombosis may offer novel therapeutic targets.

Neutrophil extracellular traps promote differentiation and function of fibroblasts.

Neutrophil activation by inflammatory stimuli and the release of extracellular chromatin structures (neutrophil extracellular traps - NETs) have been implicated in inflammatory disorders. Herein, we demonstrate that NETs released by neutrophils treated either with fibrosis-related agents, such as cigarette smoke, magnesium silicate, bleomycin, or with generic NET inducers, such as phorbol 12-myristate 13-acetate, induced activation of lung fibroblasts (LFs) and differentiation into myofibroblast (MF) phenotype. Interestingly, the aforementioned agents or IL-17 (a primary initiator of inflammation/fibrosis) had no direct effect on LF activation and differentiation. MFs treated with NETs demonstrated increased connective tissue growth factor expression, collagen production, and proliferation/migration. These fibrotic effects were significantly decreased after degradation of NETs with DNase1, heparin or myeloperoxidase inhibitor, indicating the key role of NET-derived components in LF differentiation and function. Furthermore, IL-17 was expressed in NETs and promoted the fibrotic activity of differentiated LFs but not their differentiation, suggesting that priming by DNA and histones is essential for IL-17-driven fibrosis. Additionally, autophagy was identified as the orchestrator of NET formation, as shown by inhibition studies using bafilomycin A1 or wortmannin. The above findings were further supported by the detection of NETs in close proximity to alpha-smooth muscle actin (α-SMA)-expressing fibroblasts in biopsies from patients with fibrotic interstitial lung disease or from skin scar tissue. Together, these data suggest that both autophagy and NETs are involved not only in inflammation but also in the ensuing fibrosis and thus may represent potential therapeutic targets in human fibrotic diseases.

Tissue factor expression in neutrophil extracellular traps and neutrophil derived microparticles in antineutrophil cytoplasmic antibody associated vasculitis may promote thromboinflammation and the thrombophilic state associated with the disease.

OBJECTIVES: Antineutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) is characterised by neutrophil activation. An elevated prevalence of venous thromboembolic events has been reported in AAV. Because of the critical role of neutrophils in inflammation associated thrombosis, we asked whether neutrophil tissue factor (TF) may be implicated in the thrombotic diathesis in AAV. METHODS: Neutrophils from four patients and sera from 17 patients with ANCA associated vasculitis with active disease and remission were studied. TF expression was assessed by immunoblotting and confocal microscopy. Circulating DNA levels were evaluated. TF expressing microparticles (MPs) were measured by flow cytometry and thrombin-antithrombin complex levels by ELISA. RESULTS: Peripheral blood neutrophils from four patients with active disease expressed elevated TF levels and released TF expressing neutrophil extracellular traps (NETs) and MPs. TF positive NETs were released by neutrophils isolated from the bronchoalveolar lavage and were detected in nasal and renal biopsy specimens. Elevated levels of circulating DNA and TF expressing neutrophil derived MPs were further observed in sera from patients with active disease. Induction of remission attenuated the aforementioned effects. Control neutrophils treated with sera from patients with active disease released TF bearing NETs and MPs which were abolished after IgG depletion. Treatment of control neutrophils with isolated IgG from sera from patients with active disease also resulted in the release of TF bearing NETs. TF implication in MP dependent thrombin generation was demonstrated by antibody neutralisation studies. CONCLUSIONS: Expression of TF in NETs and neutrophil derived MPs proposes a novel mechanism for the induction of thrombosis and inflammation in active AAV.

Biomarker screen for efficacy of oncolytic virotherapy in patient-derived pancreatic cancer cultures.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a tumour entity with unmet medical need. To assess the therapeutic potential of oncolytic virotherapy (OVT) against PDAC, different oncolytic viruses (OVs) are currently investigated in clinical trials. However, systematic comparisons of these different OVs in terms of efficacy against PDAC and biomarkers predicting therapeutic response are lacking. METHODS: We screened fourteen patient-derived PDAC cultures which reflect the intra- and intertumoural heterogeneity of PDAC for their sensitivity to five clinically relevant OVs, namely serotype 5 adenovirus Ad5-hTERT, herpes virus T-VEC, measles vaccine strain MV-NIS, reovirus jin-3, and protoparvovirus H-1PV. Live cell analysis, quantification of viral genome/gene expression, cell viability as well as cytotoxicity assays and titration of viral progeny were conducted. Transcriptome profiling was employed to identify potential predictive biomarkers for response to OV treatment. FINDINGS: Patient-derived PDAC cultures showed individual response patterns to OV treatment. Twelve of fourteen cultures were responsive to at least one OV, with no single OV proving superior or inferior across all cultures. Known host factors for distinct viruses were retrieved as potential biomarkers. Compared to the classical molecular subtype, the quasi-mesenchymal or basal-like subtype of PDAC was found to be more sensitive to H-1PV, jin-3, and T-VEC. Generally, expression of viral entry receptors did not correlate with sensitivity to OV treatment, with one exception: Expression of Galectin-1 (LGALS1), a factor involved in H-1PV entry, positively correlated with H-1PV induced cell killing. Rather, cellular pathways controlling immunological, metabolic and proliferative signaling appeared to determine outcome. For instance, high baseline expression of interferon-stimulated genes (ISGs) correlated with relative resistance to oncolytic measles virus, whereas low cyclic GMP-AMP synthase (cGAS) expression was associated with exceptional response. Combination treatment of MV-NIS with a cGAS inhibitor improved tumour cell killing in several PDAC cultures and cells overexpressing cGAS were found to be less sensitive to MV oncolysis. INTERPRETATION: Considering the heterogeneity of PDAC and the complexity of biological therapies such as OVs, no single biomarker can explain the spectrum of response patterns. For selection of a particular OV, PDAC molecular subtype, ISG expression as well as activation of distinct signaling and metabolic pathways should be considered. Combination therapies can overcome resistance in specific constellations. Overall, oncolytic virotherapy is a viable treatment option for PDAC, which warrants further development. This study highlights the need for personalised treatment in OVT. By providing all primary data, this study provides a rich source and guidance for ongoing developments. FUNDING: German National Science Foundation (Deutsche Forschungsgemeinschaft, DFG), German Cancer Aid (Deutsche Krebshilfe), German National Academic Scholarship Foundation (Studienstiftung des deutschen Volkes), Survival with Pancreatic Cancer Foundation.

Neutrophil extracellular traps enriched with IL-1ß and IL-17A participate in the hepatic inflammatory process of patients with non-alcoholic steatohepatitis.

Neutrophil extracellular traps (NETs) are implicated in the pathogenesis of various non-infectious inflammatory and thrombotic diseases. We investigated the presence and possible associations of NETs with various histopathologic parameters in patients with non-alcoholic steatohepatitis (NASH). We retrospectively assessed 20 liver biopsy specimens from patients with non-alcoholic fatty liver disease (NAFLD), including 17 specimens with NASH, and 14 control specimens. NETs were identified with confocal microscopy as extracellular structures with co-localization of neutrophil elastase (NE) and citrullinated histone-3. Interleukin-1ß (IL-1ß) and IL-17A were assessed with the same methodology. Histologic features of NAFLD were semi-quantitatively evaluated, and correlated with presence of NETs, neutrophil density, and platelet density/aggregates (assessed by immunohistochemistry for NE and CD42b, respectively). NETs were identified in 94.1% (16/17) of the NASH biopsy specimens; they were absent from all other NAFLD and control specimens. The presence of NETs was strongly correlated with steatosis (p = 0.003), ballooning degeneration (p < 0.001), lobular inflammation (p < 0.001), portal inflammation (p < 0.001), NAS score (p = 0.001), stage (p = 0.001), and diagnosis of NASH (p < 0.001). NETs were decorated with IL-1ß and IL-17A. Platelet aggregates were much larger in NASH specimens, as compared to controls. In conclusion, NETs are implicated in the pathogenesis of NASH. Their associations with inflammation, ballooning degeneration (a hallmark of NASH), and stage emphasize their role in the disease process. In this setting, NETs provide a vehicle for IL-1ß and IL-17A. In addition, platelet aggregation in hepatic sinusoids implies a role for thromboinflammation in NASH, and may explain the low peripheral blood platelet counts reported in patients with NASH.

Angiotensin II triggers release of neutrophil extracellular traps, linking thromboinflammation with essential hypertension.

Innate immunity and chronic inflammation are involved in atherosclerosis and atherothrombosis, leading to target organ damage in essential hypertension (EH). However, the role of neutrophils in EH is still elusive. We investigated the association between angiotensin II (Ang II) and neutrophil extracellular traps (NETs) in pathogenesis of EH. Plasma samples, kidney biopsies, and surgical specimens of abdominal aortic aneurysms (AAAs) from patients with EH were used. Cell-based assays, NETs/human aortic endothelial cell cocultures, and in situ studies were performed. Increased plasma levels of NETs and tissue factor (TF) activity were detected in untreated, newly diagnosed patients with EH. Stimulation of control neutrophils with plasma from patients with untreated EH generated TF-enriched NETs promoting endothelial collagen production. Ang II induced NETosis in vitro via an ROS/peptidylarginine deiminase type 4 and autophagy-dependent pathway. Circulating NETs and thrombin generation levels were reduced substantially in patients with EH starting treatment with Ang II receptor blockers, whereas their plasma was unable to trigger procoagulant NETs. Moreover, TF-bearing NETotic neutrophils/remnants accumulated in sites of interstitial renal fibrosis and in the subendothelial layer of AAAs. These data reveal the important pathogenic role of an Ang II/ROS/NET/TF axis in EH, linking thromboinflammation with endothelial dysfunction and fibrosis.

Patterns of LC3A Autophagy Protein Expression in Keratoacanthomas.

To investigate the expression patterns of autophagy marker light chain protein 3 (LC3A) in keratoacanthoma (KA). KAs are generally regarded as benign but malignant behavior, including rare metastases, may occur. 85 KAs were assessed for the LC3A autophagic protein by immunohistochemistry. Diffuse cytoplasmic staining and a "stone-like structure" (SLS) characterized positive expression. Thirty-four out of 85 KAs (40%) had diffuse cytoplasmic LC3A immunostaining (percentage of positive cells ranging from 5 to 60%). In contrast, only 4 of the 85 KAs (4.7%) expressed SLSs. Only one SLS was detected per histologic section of each tumor. The p53 oncoprotein was encountered in all cases with expression ranging from 1 to 90% of cells (median 30%). The Ki-67 index was expressed in 63 cases (74% of cases; range 1-50% of cells; median value 5%). Neither of these two parameters nor diffuse cytoplasmic LC3A staining was significantly correlated with SLS expression or lack thereof. Expression of SLSs, a hallmark of malignancy, was found in 4.7% of KAs. Further study is necessary to determine whether this fraction represents the exceptional cases that harbor latent malignant potential.

Rheumatoid nodules in thyroid gland parenchyma as an expression of rheumatoid arthritis: a case report.

BACKGROUND: The rheumatoid nodule is the most common extra-articular manifestation of rheumatoid arthritis. When present, it is readily identified in conventional hematoxylin and eosin sections. CASE PRESENTATION: We report a case with several rheumatoid nodules in a thyroid gland of a 33-year-old Greek woman with a 3-year history of rheumatoid arthritis treated with methotrexate, after having total thyroidectomy for hypothyroidism. CONCLUSION: To the best of our knowledge, this is the first time that rheumatoid nodules have been encountered in the thyroid gland.

Co-occurrence of Dermatomyositis and Polycythemia Unveiling Rare de Novo Neuroendocrine Prostate Tumor.

We present a case of dermatomyositis together with polycythemia as initial manifestations of a particularly rare type of prostate cancer. A 69-year-old man was hospitalized for facial erythema and symptoms of fatigue. Physical evaluation, serum creatinine phosphokinase and electromyography were consistent with dermatomyositis. In parallel, the hemoglobin level was 18.5 g/dL, serum erythropoietin levels were low normal and no JAK2 mutation was found. Given a strong suspicion of a paraneoplastic syndrome the patient underwent abdominal computed tomography revealing a prostate mass, enlarged iliac lymph nodes and a fracture of L1 due to metastasis. The unusual paraneoplastic manifestations prompted a more thorough immunohistologic examination of the needle biopsy specimen taken from the prostate, which led to the diagnosis of large cell neuroendocrine prostate carcinoma. It is a most rare type of prostate cancer, carrying a poor prognosis. To our knowledge, this is the first case in the literature associating a neuroendocrine cancer of the prostate with dermatomyositis.

Mast cells co-expressing CD68 and inorganic polyphosphate are linked with colorectal cancer.

Inflammation is a hallmark of colorectal cancer (CRC). Neutrophils are well-known mediators in tumor biology but their role in solid tumors, including CRC, was redefined by neutrophil extracellular traps (NETs). Given that it was recently demonstrated that platelet-derived polyP primes neutrophils to release NETs, we examined surgical specimens from CRC to investigate the presence of polyP, as a possible NET inducer. Biopsies with adenomas, hyperplastic polyps, inflammatory bowel disease and healthy colon tissues were used as controls. In all cases, the presence of polyP was apparent, with the main source of polyP being the mast cells. In all CRC and all adenomas with high-grade dysplasia, a substantial number of mast cells, more than 50%, co-expressed intracellularly polyP with CD68 surface antigen (CD68+), but this was not the case in the other examined disorders. PolyP-expressing mast cells were detected in close proximity with tumor cells and neutrophils, suggesting polyP expression by CD68+ mast cells among the stimuli which prime neutrophils to release NETs, in CRC. Moreover, the detection of CD68+ polyP-expressing mast cells could represent a potential prognostic marker in colorectal adenomas and/or carcinomas.

NETopathies? Unraveling the Dark Side of Old Diseases through Neutrophils.

Neutrophil extracellular traps (NETs) were initially described as an antimicrobial mechanism of neutrophils. Over the last decade, several lines of evidence support the involvement of NETs in a plethora of pathological conditions. Clinical and experimental data indicate that NET release constitutes a shared mechanism, which is involved in a different degree in various manifestations of non-infectious diseases. Even though the backbone of NETs is similar, there are differences in their protein load in different diseases, which represent alterations in neutrophil protein expression in distinct disorder-specific microenvironments. The characterization of NET protein load in different NET-driven disorders could be of significant diagnostic and/or therapeutic value. Additionally, it will provide further evidence for the role of NETs in disease pathogenesis, and it will enable the characterization of disorders in which neutrophils and NET-dependent inflammation are of critical importance.

Gradient Infiltration of Neutrophil Extracellular Traps in Colon Cancer and Evidence for Their Involvement in Tumour Growth.

BACKGROUND: The role of neutrophils in tumour biology is largely unresolved. Recently, independent studies indicated either neutrophil extracellular traps (NETs) or Tissue Factor (TF) involvement in cancer biology and associated thrombosis. However, their individual or combined role in colonic adenocarcinoma is still unexplored. METHODS: Colectomy tissue specimens and variable number of draining lymph nodes were obtained from ten patients with adenocarcinoma of the colon. NETs deposition and neutrophil presence as well as TF expression were examined by immunostaining. The effect of NETs on cancer cell growth was studied in in vitro co-cultures of Caco-2 cell line and acute myeloid leukemia primary cells. Proliferation and apoptosis/necrosis of cancer cells were analyzed by flow cytometry. RESULTS: TF-bearing NETs and neutrophil localization were prominent in tumour sections and the respective metastatic lymph nodes. Interestingly, neutrophil infiltration and NETs concentration were gradually reduced from the tumour mass to the distal margin. The in vitro-generated NETs impeded growth of cancer cell cultures by inducing apoptosis and/or inhibiting proliferation. CONCLUSIONS: These data support further the role of neutrophils and NETs in cancer biology. We also suggest their involvement on cancer cell growth.