Prevalence of major depressive disorder in 51,658 otherwise healthy adult Danes: Sex differences in symptomatology and prediction of future anti-depressive medication.

Major Depressive Disorder (MDD) is a heterogeneous disease, which displays sex differences in symptomatology. This study aimed to assess point prevalence of MDD in undiagnosed, healthy adults as well as sex differences in symptomatology and clarify if specific symptoms increased the later need for anti-depressive medication. The study included 51,658 blood donors. Depressive symptoms were assessed according to ICD-10 using the Major Depression Inventory. Demographics, previous MDD, anti-depressive medication were collected from questionnaires and population registers. Descriptive, Logistic and Cox regression analyses were conducted. In total, 1.15% participants met the criteria for MDD. Women were significantly more likely to experience "increased appetite" and less likely to experience "a feeling of life not worth living", compared to men. MDD significantly associated with an increased hazard of later receiving a prescription for anti-depressive medication. The risk increased proportionally with increasing MDD severity. The two symptoms, "feeling that life is not worth living" and "trouble sleeping" were the strongest individual predictive symptoms of future anti-depressive medication in women and men, respectively. The results confirm findings in MDD patient groups. The diagnostic and prognostic value should be investigated further to address their potential as part of the clinical assessment.

Early Laboratory Diagnosis of COVID-19 by Antigen Detection in Blood Samples of the SARS-CoV-2 Nucleocapsid Protein.

The purpose of this study was to characterize the diagnostic performance of a newly developed enzyme-linked immunosorbent assay (ELISA) for detection of SARS-CoV-2 nucleocapsid protein (NP) in blood. Blood samples were collected during hospitalization of 165 inpatients with PCR-confirmed SARS-CoV-2 infection and from 505 outpatients predominantly with relevant symptoms of COVID-19 simultaneously with PCR testing. For the 143 inpatients who had their first blood sample collected within 2 weeks after PCR-confirmed infection, the diagnostic sensitivity of the ELISA was 91.6%. The mean NP concentration of the 131 ELISA-positive blood samples was 1,734 pg/ml (range, 10 to 3,840 pg/ml). An exponential decline in NP concentration was observed for 368 blood samples collected over the first 4 weeks after PCR-confirmed SARS-CoV-2 infection, and all blood samples taken later had an NP concentration below the 10-pg/ml diagnostic cutoff. The diagnostic sensitivity of the ELISA was 81.4% for the 43 blood samples collected from outpatients with a simultaneous positive PCR test, and the mean NP concentration of the 35 ELISA-positive samples was 157 pg/ml (range, 10 to 1,377 pg/ml). For the 462 outpatients with a simultaneous negative PCR test, the diagnostic specificity of the ELISA was 99.8%. In conclusion, the SARS-CoV-2 NP ELISA is a suitable laboratory diagnostic test for COVID-19, particularly for hospitals, where blood samples are readily available and screening of serum or plasma by ELISA can facilitate prevention of nosocomial infections and reduce the requirement for laborious swab sampling and subsequent PCR analysis to confirmatory tests only.

The impact of health-related quality of life and depressive symptoms on blood donor career-Results from the Danish blood donor study.

BACKGROUND: Blood donors report better health-related quality of life (HRQL) than non-donors. Likewise, donors reporting good health are less likely to stop donating and have a higher donation frequency. This is evidence of the healthy donor effect (HDE). This study is the first to investigate the impact of HRQL and depressive symptoms on subsequent donor career. STUDY DESIGN AND METHODS: Prospective cohort study includes 102,065 participants from the Danish Blood Donor Study applying the 12-item short-form health survey (SF-12) measuring a mental (MCS) and a physical component score (PCS) and the Major Depression Inventory (MDI). Poisson and Cox regression models were used to assess the effect of SF-12 and MDI scores on donation frequency and donor cessation. Higher MCS/PCS scores indicate good HRQL, while higher MDI score indicates higher experience of depressive symptoms. RESULTS: For both sexes, MCS was positively correlated with donation frequency for up to 5 years, and similarly for PCS among women. A negative correlation between MDI score and donation frequency in the year following assessment was observed only among men. No correlation was observed among women. An increase in both MCS and PCS was associated with a lower risk of donation cessation in both sexes, while an increase in MDI score was only associated with an increased risk of donation cessation in men. CONCLUSION: MCS, PCS, and MDI score affect donor career. Thus, adjusting for donation frequency may reduce HDE-bias in donor health research. However, because of the small effect sizes, other ways of quantifying HDE may be beneficial.

Cohort profile: Copenhagen Hospital Biobank - Cardiovascular Disease Cohort (CHB-CVDC): Construction of a large-scale genetic cohort to facilitate a better understanding of heart diseases.

PURPOSE: The aim of Copenhagen Hospital Biobank-Cardiovascular Disease Cohort (CHB-CVDC) is to establish a cohort that can accelerate our understanding of CVD initiation and progression by jointly studying genetics, diagnoses, treatments and risk factors. PARTICIPANTS: The CHB-CVDC is a large genomic cohort of patients with CVD. CHB-CVDC currently includes 96 308 patients. The cohort is part of CHB initiated in 2009 in the Capital Region of Denmark. CHB is continuously growing with ~40 000 samples/year. Patients in CHB were included in CHB-CVDC if they were above 18 years of age and assigned at least one cardiovascular diagnosis. Additionally, up-to 110 000 blood donors can be analysed jointly with CHB-CVDC. Linkage with the Danish National Health Registries, Electronic Patient Records, and Clinical Quality Databases allow up-to 41 years of medical history. All individuals are genotyped using the Infinium Global Screening Array from Illumina and imputed using a reference panel consisting of whole-genome sequence data from 8429 Danes along with 7146 samples from North-Western Europe. Currently, 39 539 of the patients are deceased. FINDINGS TO DATE: Here, we demonstrate the utility of the cohort by showing concordant effects between known variants and selected CVDs, that is, >93% concordance for coronary artery disease, atrial fibrillation, heart failure and cholesterol measurements and 85% concordance for hypertension. Furthermore, we evaluated multiple study designs and the validity of using Danish blood donors as part of CHB-CVDC. Lastly, CHB-CVDC has already made major contributions to studies of sick sinus syndrome and the role of phytosterols in development of atherosclerosis. FUTURE PLANS: In addition to genetics, electronic patient records, national socioeconomic and health registries extensively characterise each patient in CHB-CVDC and provides a promising framework for improved understanding of risk and protective variants. We aim to include other measurable biomarkers for example, proteins in CHB-CVDC making it a platform for multiomics cardiovascular studies.

A Retrospective Chart Review Study of Real-World Use of Talimogene Laherparepvec in Unresectable Stage IIIB-IVM1a Melanoma in Four European Countries.

INTRODUCTION: Talimogene laherparepvec (T-VEC; IMLYGIC®, Amgen Inc.) is an oncolytic immunotherapy approved in Europe for the treatment of unresectable metastatic melanoma (stage IIIB-IVM1a). This study characterised real-world use of T-VEC in four European countries. METHODS: Data on demographics, treatment pattern, safety, and clinical effectiveness were examined in a retrospective chart review of patients with stage IIIB-IVM1a unresectable melanoma treated with T-VEC in surgical (the Netherlands) and medical (Austria, Germany, UK) oncology settings. RESULTS: Overall, 66 patients were included (the Netherlands: n = 31; Austria, Germany, UK: n = 35). The median age was 69 years and 59.1% were female. At the time of T-VEC initiation, 47 patients (71.2%) had stage IIIB/C disease; of these, 30 were from the Netherlands. Although 72.7% patients overall received T-VEC as first-line therapy, this was higher in the Netherlands than the other countries (93.5% vs 54.3%). Of the 47 patients who discontinued T-VEC, 26 (55.3%) had no remaining injectable lesions (potentially indicating complete response); 20/26 of these patients were from the Netherlands. One patient discontinued T-VEC due to toxicity. CONCLUSION: This study is the first comprehensive multinational evaluation of the use of T-VEC to treat unresectable stage IIIB/C-IVM1a melanoma in real-world clinical practice in Europe. The differences between European countries were apparent, with physicians in the Netherlands using T-VEC in patients with earlier advanced disease stage and in the first-line setting compared with other countries.

Real-World Use of Talimogene Laherparepvec in German Patients with Stage IIIB to IVM1a Melanoma: A Retrospective Chart Review and Physician Survey.

INTRODUCTION: Talimogene laherparepvec is a first-in-class oncolytic immunotherapy for intratumoral injection with proven efficacy and tolerability in patients with unresectable early metastatic melanoma (stage IIIB-IVM1a) in the pivotal phase III OPTiM study. The objective was to characterize melanoma patients treated with talimogene laherparepvec in routine clinical practice in Germany. METHODS: A retrospective chart review was conducted in unresectable stage IIIB-IVM1a melanoma patients. Data on demographics, disease and medical history, and use of talimogene laherparepvec were collected. A survey was also conducted to understand physician treatment decisions. RESULTS: Data for 27 patients who initiated talimogene laherparepvec between June 2016 and July 2017 were analyzed (median age 68; stage IIIB/C disease 56%). All patients had prior surgery, and over half had repeated resections for recurrent disease (median 3). Overall, 48% of patients received at least one prior local treatment, mainly radiation therapy or electrochemotherapy. Talimogene laherparepvec was first-line systemic therapy in 63% of patients. The most frequent prior systemic treatment was immunotherapy (7/27 patients). At end of follow-up, 13 patients were still on talimogene laherparepvec and 14 patients had discontinued treatment. Among those who discontinued, 8 (57%) did not receive subsequent systemic therapy. Only one patient receiving first-line talimogene laherparepvec received a subsequent systemic therapy. Three patients stopped treatment because of no remaining injectable lesions. Median treatment duration was 22.1 weeks overall and 27.9 weeks in stage IIIB/C disease patients. Nearly all cutaneous lesions (93%) were injected with talimogene laherparepvec compared to subcutaneous (83%) and nodal lesions (77%). No new safety signals were reported. The main reasons given in the physician survey for treating with talimogene laherparepvec were good tolerability, overall efficacy, and lack of contraindications. CONCLUSION: Talimogene laherparepvec is now included as a routine treatment option for unresectable early metastatic melanoma in Germany. This study characterizes the first patients treated with talimogene laherparepvec in Europe and confirms the good tolerability observed in clinical trials. TRIAL REGISTRATION: EUPAS registry, EUPAS17410. FUNDING: Amgen Inc.

Global Distribution of Human-Associated Fecal Genetic Markers in Reference Samples from Six Continents.

Numerous bacterial genetic markers are available for the molecular detection of human sources of fecal pollution in environmental waters. However, widespread application is hindered by a lack of knowledge regarding geographical stability, limiting implementation to a small number of well-characterized regions. This study investigates the geographic distribution of five human-associated genetic markers (HF183/BFDrev, HF183/BacR287, BacHum-UCD, BacH, and Lachno2) in municipal wastewaters (raw and treated) from 29 urban and rural wastewater treatment plants (750-4 400 000 population equivalents) from 13 countries spanning six continents. In addition, genetic markers were tested against 280 human and nonhuman fecal samples from domesticated, agricultural and wild animal sources. Findings revealed that all genetic markers are present in consistently high concentrations in raw (median log10 7.2-8.0 marker equivalents (ME) 100 mL-1) and biologically treated wastewater samples (median log10 4.6-6.0 ME 100 mL-1) regardless of location and population. The false positive rates of the various markers in nonhuman fecal samples ranged from 5% to 47%. Results suggest that several genetic markers have considerable potential for measuring human-associated contamination in polluted environmental waters. This will be helpful in water quality monitoring, pollution modeling and health risk assessment (as demonstrated by QMRAcatch) to guide target-oriented water safety management across the globe.

Prognostic factors and outcomes in metastatic uveal melanoma treated with programmed cell death-1 or combined PD-1/cytotoxic T-lymphocyte antigen-4 inhibition.

BACKGROUND: Uveal melanoma (UM) is an ocular malignancy with high potential for metastatic spread. In contrast to cutaneous melanoma, immunotherapy has not yet shown convincing efficacy in patients with UM. Combined immune checkpoint blockade with checkpoint programmed cell death-1 (PD-1) and checkpoint cytotoxic T-lymphocyte antigen-4 (CTLA-4) inhibition has not been systematically assessed for UM to date. PATIENTS AND METHODS: Patients with metastatic UM treated with either PD-1 inhibitor monotherapy or combined PD-1 inhibitor and ipilimumab (an anti-CTLA-4 monoclonal antibody) were included from 20 German skin cancer centres. Records from 96 cases were analysed for treatment outcomes. Clinical and blood parameters associated with overall survival (OS) or treatment response were identified with multivariate Cox regression and binary logistic regression. RESULTS: Eighty-six patients were treated with PD-1 inhibitors only (n = 54 for pembrolizumab, n = 32 for nivolumab) with a centrally confirmed response rate of 4.7%. Median OS was 14 months for pembrolizumab-treated and 10 months for nivolumab-treated patients (p = 0.765). Fifteen patients were treated with combined immune checkpoint blockade with partial response observed in two cases. Median OS was not reached in this group. Multivariate Cox regression identified Eastern Cooperative Oncology Group (ECOG) performance status (p = 0.002), elevated serum levels of lactate dehydrogenase (LDH) (p = 0.002) and C-reactive protein (CRP) (p = 0.001), and a relative eosinophil count (REC) <1.5% (p = 0.002) as independent risk factors for poor survival. Patients with elevated CRP and LDH and a REC <1.5% were at highest risk for disease progression and death (p = 0.001). CONCLUSIONS: Blood markers predict survival in metastatic UM treated with immune checkpoint blockade. Normal serum levels of LDH and CRP and a high REC may help identify patients with better prognosis.

Ferritin-stimulated lipid peroxidation, lysosomal leak, and macroautophagy promote lysosomal "metastability" in primary hepatocytes determining in vitro cell survival.

Several pathologies are associated with elevated levels of serum ferritin, for which growth inhibitory properties have been reported; however, the underlying mechanisms are still poorly defined. Previously we have described cytotoxic properties of isoferritins released from primary hepatocytes in vitro, which induce apoptosis in an iron and oxidative stress-dependent mode. Here we show that this ferritin species stimulates endosome clustering and giant endosome formation in primary hepatocytes accompanied by enhanced lysosomal membrane permeability (LMP). In parallel, protein modification by lipid peroxidation-derived 4-hydroxynonenal (HNE) is strongly promoted by ferritin, the HNE-modified proteins (HNE-P) showing remarkable aggregation. Emphasizing the prooxidant context, GSH is rapidly depleted and the GSH/GSSG ratio is substantially declining in ferritin-treated cells. Furthermore, ferritin triggers a transient upregulation of macroautophagy which is abolished by iron chelation and apparently supports HNE-P clearance. Macroautophagy inhibition by 3-methyladenine strongly amplifies ferritin cytotoxicity in a time- and concentration-dependent mode, suggesting an important role of macroautophagy on cellular responses to ferritin endocytosis. Moreover, pointing at an involvement of lysosomal proteolysis, ferritin cytotoxicity and lysosome fragility are aggravated by the protease inhibitor leupeptin. In contrast, EGF which suppresses ferritin-induced cell death attenuates ferritin-mediated LMP. In conclusion, we propose that HNE-P accumulation, lysosome dysfunction, and macroautophagy stimulated by ferritin endocytosis provoke lysosomal "metastability" in primary hepatocytes which permits cell survival as long as in- and extrinsic determinants (e.g., antioxidant availability, damage repair, EGF signaling) keep the degree of lysosomal destabilization below cell death-inducing thresholds.

Performance characteristics of qPCR assays targeting human- and ruminant-associated bacteroidetes for microbial source tracking across sixteen countries on six continents.

Numerous quantitative PCR assays for microbial fecal source tracking (MST) have been developed and evaluated in recent years. Widespread application has been hindered by a lack of knowledge regarding the geographical stability and hence applicability of such methods beyond the regional level. This study assessed the performance of five previously reported quantitative PCR assays targeting human-, cattle-, or ruminant-associated Bacteroidetes populations on 280 human and animal fecal samples from 16 countries across six continents. The tested cattle-associated markers were shown to be ruminant-associated. The quantitative distributions of marker concentrations in target and nontarget samples proved to be essential for the assessment of assay performance and were used to establish a new metric for quantitative source-specificity. In general, this study demonstrates that stable target populations required for marker-based MST occur around the globe. Ruminant-associated marker concentrations were strongly correlated with total intestinal Bacteroidetes populations and with each other, indicating that the detected ruminant-associated populations seem to be part of the intestinal core microbiome of ruminants worldwide. Consequently tested ruminant-targeted assays appear to be suitable quantitative MST tools beyond the regional level while the targeted human-associated populations seem to be less prevalent and stable, suggesting potential for improvements in human-targeted methods.

NF-kappaB promotes epithelial-mesenchymal transition, migration and invasion of pancreatic carcinoma cells.

The transcription factor NF-kappaB is constitutively active in pancreatic adenocarcinoma. Here we explore the contribution of NF-kappaB to the malignant phenotype of pancreatic cancer cells in addition to its anti-apoptotic role. Block of NF-kappaB signalling by non-destructible IkappaBalpha rendered cells resistant to TGF-beta-induced epithelial-mesenchymal transition (EMT). In contrast, NF-kappaB activation by TNF-alpha or expression of constitutively active IKK2 induced an EMT-phenotype with up-regulation of vimentin and ZEB1, and down-regulation of E-cadherin. EMT could also be induced in cells with defective TGF-beta signalling. Functional assays demonstrated reduced or strongly enhanced migration and invasion upon NF-kappaB inhibition or activation, respectively.

BI 5700, a Selective Chemical Inhibitor of IκB Kinase 2, Specifically Suppresses Epithelial-Mesenchymal Transition and Metastasis in Mouse Models of Tumor Progression.

Increasing evidence suggests that processes termed epithelial-mesenchymal transitions (EMTs) play a key role in therapeutic resistance, tumor recurrence, and metastatic progression. NF-κB signaling has been previously identified as an important pathway in the regulation of EMT in a mouse model of tumor progression. However, it remains unclear whether there is a broad requirement for this pathway to govern EMT and what the relative contribution of IKK family members acting as upstream NF-κB activators is toward promoting EMT and metastasis. To address this question, we have used a novel, small-molecule inhibitor of IκB kinase 2 (IKK2/IKKß), termed BI 5700. We investigated the role of IKK2 in a number of mouse models of EMT, including TGFß-induced EMT in the mammary epithelial cell line EpRas, CT26 colon carcinoma cells, and 4T1 mammary carcinoma cells. The latter model was also used to evaluate in vivo activities of BI 5700.We found that BI 5700 inhibits IKK2 with an IC(50) of 9 nM and was highly selective as compared to other IKK family members (IKK1, IKKε, and TBK1) and other kinases. BI 5700 effectively blocks NF-κB activity in EpRas cells and prevents TGFß-induced EMT. In addition, BI 5700 reverts EMT in mesenchymal CT26 cells and prevents EMT in the 4T1 model. Oral application of BI 5700 significantly interferes with metastasis after mammary fat-pad injection of 4T1 cells, yielding fewer, smaller, and more differentiated metastases as compared to vehicle-treated control animals. We conclude that IKK2 is a key regulator of both the induction and maintenance of EMT in a panel of mouse tumor progression models and that the IKK2 inhibitor BI 5700 constitutes a promising candidate for the treatment of metastatic cancers.

Multiple Scalp Lesions in a Patient with Keratitis, Ichthyosis and Deafness Syndrome Mimicking Metastatic Squamous Cell Carcinoma on 18F-FDG PET/CT.

We report the case of a 17-year-old girl with keratitis, ichthyosis, and deafness (KID) syndrome. As a complication of her KID syndrome she developed squamous cell carcinoma at the left index finger. Additional clinical features were multiple soft tissue lesions over the scalp mimicking metastatic disease on 18F-FDG PET/CT. To our knowledge, this is the first case report about the uptake pattern of KID syndrome associated skin lesions on whole body PET/CT with 18F-FDG.

Cell-free protein synthesis for analysis by NMR spectroscopy.

Cell-free protein synthesis offers fast and inexpensive access to selectively isotope labeled proteins that can be measured by NMR spectroscopy in the presence of all the unlabeled proteins in the reaction mixture. No chromatographic purification is required. Using an extract from Escherichia coli in a simple dialysis system, the target protein can be prepared at a typical concentration of about 1 mg/ml, which is sufficient for subsequent analysis by NMR. This chapter describes in detail the protocol used in the authors' laboratory.

Surface movement in water of splendipherin, the aquatic male sex pheromone of the tree frog Litoria splendida.

The aquatic sex pheromone splendipherin (GLVSSIGKALGGLLADVVKSKGQPA-OH) of the male green tree frog Litoria splendida moves across the surface of water to reach the female. Surface pressure and X-ray reflectometry measurements confirm that splendipherin is a surface-active molecule, and are consistent with it having an ordered structure, whereby the hydrophilic portion of the peptide interacts with the underlying water and the hydrophobic region is adjacent to the vapour phase. The movement of splendipherin over the surface of water is caused by a surface pressure gradient. In order to better define the structure of splendipherin at the water/air interface we used 2D NMR studies of the pheromone with the solvent system trifluoroethanol/water (1 : 1 v/v). In this solvent system, splendipherin adopts a bent alpha helix from residues V3 to K21. The bending of the helix occurs in the centre of the peptide in the vicinity of G11 and G12. The region of splendipherin from V3 to G11 has well-defined amphipathicity, whereas the amphipathicity from G12 to A25 is reduced by K19 and P24 intruding into the hydrophobic and hydrophilic regions respectively. A helical structure is consistent with X-ray reflectometry data.

Cupiennin 1a, an antimicrobial peptide from the venom of the neotropical wandering spider Cupiennius salei, also inhibits the formation of nitric oxide by neuronal nitric oxide synthase.

Cupiennin 1a (GFGALFKFLAKKVAKTVAKQAAKQGAKYVVNKQME-NH2) is a potent venom component of the spider Cupiennius salei. Cupiennin 1a shows multifaceted activity. In addition to known antimicrobial and cytolytic properties, cupiennin 1a inhibits the formation of nitric oxide by neuronal nitric oxide synthase at an IC50 concentration of 1.3 +/- 0.3 microM. This is the first report of neuronal nitric oxide synthase inhibition by a component of a spider venom. The mechanism by which cupiennin 1a inhibits neuronal nitric oxide synthase involves complexation with the regulatory protein calcium calmodulin. This is demonstrated by chemical shift changes that occur in the heteronuclear single quantum coherence spectrum of 15N-labelled calcium calmodulin upon addition of cupiennin 1a. The NMR data indicate strong binding within a complex of 1 : 1 stoichiometry.

Management of refractory early-stage cutaneous T-cell lymphoma.

Cutaneous T-cell lymphoma (CTCL) is a heterogeneous group of non-Hodgkin's lymphomas that manifest primarily in the skin. Mycosis fungoides is recognized as the most common type of CTCL. Patients with early-stage CTCL usually have a benign and chronic disease course. However, although there is a wide array of therapeutic options for early-stage CTCL, not all patients respond to these individual therapies, resulting in refractory cutaneous disease over time. Refractory early-stage CTCL poses an important therapeutic challenge, as one of the principal treatment goals is to keep the disease confined to the skin, thereby preventing disease progression. Much of the focus of current research has been on the evaluation of already available skin-directed therapies and biologic response modifiers and combination regimens thereof, such as the combination of psoralen and UVA (PUVA) with interferon-alpha or retinoids. Recent novel developments include oral bexarotene, a retinoid X receptor-selective retinoid that has activity in all stages of CTCL and has been shown to be effective in patients with refractory early-stage disease as well as advanced-stage disease. Likewise, the topical gel formulation of bexarotene has proved to be an important therapeutic option in patients with refractory or relapsed lesions. Oral bexarotene and topical bexarotene have been approved by the US FDA for the treatment of refractory CTCL. Systemic chemotherapy is typically reserved for advanced-stage CTCL and is usually not recommended for early-stage, skin-limited disease. However, recent exploratory studies indicate that low-dose methotrexate may represent an overall well tolerated therapy in a subset of patients with refractory early-stage CTCL, as may pegylated liposomal doxorubicin, which is currently being investigated in this specific clinical setting. Another recently FDA-approved therapy is the interleukin-2 fusion toxin denileukin diftitox, which is now well established to play a role in the treatment of refractory CTCL, including early-stage extensive plaque disease. The value of other agents, such as topical tazarotene, topical methotrexate, and topical imiquimod, and of novel immunomodulatory approaches including monoclonal antibodies, still needs to be assessed for refractory early-stage CTCL.

Expression of stromal cell markers in distinct compartments of human skin cancers.

BACKGROUND: The importance of changes in the supporting tumor stroma for cancer initiation and progression is well established. The characteristics of an activated tumor stroma, however, are not completely understood. In an effort to better characterize the desmoplastic response to human skin tumors, we evaluated the expression pattern of three stromal cell markers, fibroblast-activation protein (FAP), endoglyx-1, and endosialin, in a series of melanocytic and epithelial skin tumors. METHODS: Immunohistochemistry using antibodies against FAP, endoglyx-1, and endosialin was carried out in skin samples obtained from 43 patients. Furthermore, microarray data from an independent set of human skin cancers were analyzed. RESULTS: FAP-positive fibroblasts were detected in all tumor tissues tested, including cases of melanocytic nevi, melanoma metastases, basal cell carcinomas, and squamous cell carcinomas. In cutaneous melanoma metastases, we identified different compartments within the stromal response on the basis of the regions of FAP expression. Endoglyx-1 expression was confined to normal and tumor blood vessel endothelium including 'hot spots' of neoangiogenesis within the cutaneous melanoma metastases. Endosialin was selectively induced in subsets of small- and medium-sized tumor blood vessels in melanoma metastases and squamous cell carcinomas. CONCLUSIONS: These data describe novel aspects of stromal marker expression in distinct compartments of human skin tumors and may point to potential targets for novel therapeutic strategies aimed at the tumor stroma.