Differentiating iron-loading anemias using a newly developed and analytically validated ELISA for human serum erythroferrone.

Erythroferrone (ERFE), the erythroid regulator of iron metabolism, inhibits hepcidin to increase iron availability for erythropoiesis. ERFE plays a pathological role during ineffective erythropoiesis as occurs in X-linked sideroblastic anemia (XLSA) and β-thalassemia. Its measurement might serve as an indicator of severity for these diseases.

Phosphoserine aminotransferase 1 is associated to poor outcome on tamoxifen therapy in recurrent breast cancer.

In a previous study, we detected a significant association between phosphoserine aminotransferase 1 (PSAT1) hyper-methylation and mRNA levels to outcome to tamoxifen treatment in recurrent disease. We here aimed to study the association of PSAT1 protein levels to outcome upon tamoxifen treatment and to obtain more insight in its role in tamoxifen resistance. A cohort of ER positive, hormonal therapy naïve primary breast carcinomas was immunohistochemically (IHC) stained for PSAT1.

Quantification of patient-specific assay interference in different formats of enzyme-linked immunoassays for therapeutic monoclonal antibodies.

Background: The use of therapeutic monoclonal antibodies for clinical purposes has significantly increased in recent years, and so has the need to monitor antibody concentrations. This may be achieved using the well-established enzyme linked immunoassay (ELISA) methods; however, these assays are subject to a variety of interferences.

Methods: In the present study, the authors have tested the ELISA methods for quantifying bevacizumab (BVZ) to investigate this interference.

Stromal cell-associated expression of kallikrein-related peptidase 6 (KLK6) indicates poor prognosis of ovarian cancer patients.

Several members of the human kallikrein-related peptidase family, including KLK6, are up-regulated in ovarian cancer. High KLK6 mRNA or protein expression, measured by quantitative polymerase chain reaction and enzyme-linked immunoassay, respectively, was previously found to be associated with a shortened overall and progression-free survival (OS and PFS, respectively). In the present study, we aimed at analyzing KLK6 protein expression in ovarian cancer tissue by immunohistochemistry.

TRIB3 protein denotes a good prognosis in breast cancer patients and is associated with hypoxia sensitivity.

Background: Tribbles homolog 3 (TRIB3) is a pseudokinase involved in the regulation of several signaling pathways involved in cell survival and/or cell stress. Here, we determined the correlation between breast cancer prognosis and TRIB3 protein levels and established the role of TRIB3 in cell survival after hypoxia and/or radiotherapy.

Material And Methods: TRIB3 mRNA and protein were quantified in a new independent breast cancer patient cohort using QPCR and a new specific avian antibody against TRIB3.

Immunochemical and mass-spectrometry-based serum hepcidin assays for iron metabolism disorders.

Background: Hepcidin is an iron-regulatory peptide hormone that consists of 3 isoforms: bioactive hepcidin-25, and inactive hepcidin-22 and hepcidin-20. Hepcidin is instrumental in the diagnosis and monitoring of iron metabolism disorders, but reliable methods for its quantification in serum are sparse, as is knowledge of their relative analytical strengths and clinical utility.

Methods: We developed a competitive (c)-ELISA and an immunocapture TOF mass-spectrometry (IC-TOF-MS) assay.

Activation of human pro-urokinase by unrelated proteases secreted by Pseudomonas aeruginosa.

Pathogenic bacteria, including Pseudomonas aeruginosa, interact with and engage the host plasminogen (Plg) activation system, which encompasses the urokinase (uPA)-type Plg activator, and is involved in extracellular proteolysis, including matrilysis and fibrinolysis. We hypothesized that secreted bacterial proteases might contribute to the activation of this major extracellular proteolytic system, thereby participating in bacterial dissemination. We report that LasB, a thermolysin-like metalloprotease secreted by Ps.

Polyclonal antibodies against kallikrein-related peptidase 4 (KLK4): immunohistochemical assessment of KLK4 expression in healthy tissues and prostate cancer.

KLK4 is a member of the human kallikrein-related peptidase family of (chymo)trypsin-like serine proteases. The aim of the present study was to generate polyclonal antibodies (pAb) directed against KLK4 for the analysis of KLK4 by immunohistochemistry in human tissues. Recombinantly expressed human mature KLK4 was used for immunization of chickens.

Kallikrein-related peptidase 4: a new activator of the aberrantly expressed protease-activated receptor 1 in colon cancer cells.

Certain serine proteases are considered to be signaling molecules that act through protease-activated receptors (PARs). Our recent studies have implicated PAR1 and PAR4 (thrombin receptors) and PAR2 (trypsin receptor) in human colon cancer growth. Here we analyzed the expression of KLK4, a member of the kallikrein-related peptidase (KLK) family of serine proteases and explored whether this member can activate PAR1 and PAR2 in human colon cancer cells.

High-sensitive radioimmunoassay for human serum hepcidin.

The hepatic peptide hormone hepcidin plays a central role in body iron metabolism. Despite its promise as a biomarker, the availability of high-sensitive hepcidin assays is still limited. We developed and validated a RadioImmunoAssay (RIA) to measure hepcidin quantitatively in human serum.

Components of the plasminogen activator system and their complexes in renal cell and bladder cancer: comparison between normal and matched cancerous tissues.

Objective: To analyse and compare the concentration of plasminogen activator (PA), urokinase-type PA (uPA), tissue-type PA (tPA), PA inhibitor (PAI)-1 and PAI-2, and the complexes uPA-PAI-1 and tPA-PAI-1 and calculated uPA and tPA uncomplexed with PAI-1 ('free') in urothelial cell carcinoma and matched benign urothelium, and in renal cell carcinoma (RCC) and matched benign renal tissue.

Patients And Methods: Tissue samples were obtained during cystectomy (33 patients) and nephrectomy (55), and specific enzyme-linked immunosorbent assays were used to assess the PA components in extracts of these tissues.

Results: Tissue levels of uPA-PAI-1 and tPA-PAI-1, but also PAI-1 itself, were greater in tumorous bladder and kidney tissue than in matched normal tissue (by 1.

Association between high levels of blood macrophage migration inhibitory factor, inappropriate adrenal response, and early death in patients with severe sepsis.

Background: Identification of new therapeutic targets remains an imperative goal to improve the morbidity and mortality associated with severe sepsis and septic shock. Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine and counterregulator of glucocorticoids, has recently emerged as a critical mediator of innate immunity and experimental sepsis, and it is an attractive new target for the treatment of sepsis.

Methods: Circulating concentrations of MIF were measured in 2 clinical trial cohorts of 145 pediatric and adult patients who had severe sepsis or septic shock caused predominantly by infection with Neisseria meningitidis or other gram-negative bacteria, to study the kinetics of MIF during sepsis, to analyze the interplay between MIF and other mediators of sepsis or stress hormones (adrenocorticotropic hormone and cortisol), and to determine whether MIF is associated with patient outcome.

Development of a sensitive ELISA for the quantification of human tumour necrosis factor-alpha using 4 polyclonal antibodies.

Despite the availability of many assays to measure concentrations of tumour necrosis factor alpha (TNF-alpha) in body fluids, these assays often lack specificity or sensitivity and are often of questionable reliability, resulting in inconsistent results. Therefore, we have developed an ELISA that is sensitive, reliable and not susceptible to disturbances by interfering substances such as heterophilic antibodies. The assay involves a combination of four polyclonal antibodies.

The prognostic value of BCAR1 in patients with primary breast cancer.

Purpose: BCAR1, the human homologue of the rat p130Cas protein, was identified in a functional screen for human breast cancer cell proliferation resistant to antiestrogen drugs. Here, we study the prognostic value of quantitative BCAR1 levels in a large series of breast cancer specimens.

Experimental Design: A specific ELISA was developed to measure BCAR1 protein levels in 2593 primary breast tumor cytosols.

Development of an ELISA for measurement of BCAR1 protein in human breast cancer tissue.

Background: High concentrations of breast cancer anti-estrogen resistance 1 (BCAR1) protein measured by Western blotting in primary breast tumor cytosols are associated with early disease progression and failure of tamoxifen therapy. The aim of the present study was to develop an ELISA to measure BCAR1 quantitatively in extracts of human breast cancer tissue.

Methods: A recombinant fragment of BCAR1 (the human homolog of murine p130Cas) was produced in bacterial M15 cells, purified, and injected into chickens and rabbits.

Complex of urokinase-type plasminogen activator with its type 1 inhibitor predicts poor outcome in 576 patients with lymph node-negative breast carcinoma.

Background: The ability of a solid tumor to grow and metastasize has a significant dependence on protease systems, such as the plasminogen activation system. The plasminogen activation system includes the urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1), among other molecules. Both uPA and PAI-1 are established prognostic factors for patients with breast carcinoma.

The complex between urokinase-type plasminogen activator (uPA) and its type-1 inhibitor (PAI-I) independently predicts response to first-line endocrine therapy in advanced breast cancer.

It has been shown that urokinase-type plasminogen activator (uPA) and its main inhibitor (PAI-I) have predictive value for therapy success in advanced breast cancer. Levels of the complex between uPA and PAI-I, formed when both molecules are in their active form, might have superior predictive power. Here, we investigate the association between levels of uPA:PAI-I complex and rate of response to first-line systemic therapy for advanced breast cancer.

Predictive impact of urokinase-type plasminogen activator: plasminogen activator inhibitor type-1 complex on the efficacy of adjuvant systemic therapy in primary breast cancer.

One of the most thoroughly studied systems in relation to its prognostic relevance in patients with breast cancer, is the plasminogen activation system. This system comprises of, among others, the urokinase-type plasminogen activator (uPA) and its main inhibitor (PAI-1). In this study we investigated whether the uPA:PAI-1 complex is associated with the responsiveness of patients with primary breast cancer to adjuvant systemic therapy.

Combined vascular endothelial growth factor and TP53 status predicts poor response to tamoxifen therapy in estrogen receptor-positive advanced breast cancer.

Purpose: In recent studies, we showed that TP53 gene mutation or high levels of cytosolic vascular endothelial growth factor (VEGF) in estrogen receptor (ER)-alpha-positive primary breast tumors predict a poor disease outcome for patients treated with first-line tamoxifen for advanced disease. Mutant TP53 may up-regulate VEGF, whereas, on the other hand, wild-type TP53 may decrease VEGF production.

Experimental Design: In the present study, we aimed to assess the combined predictive value of TP53 gene mutation and VEGF status of 160 advanced breast cancer patients with ER-positive tumors who were treated with tamoxifen (median follow-up from start of tamoxifen treatment, 64 months).