Blood-based detection of lung cancer using cysteine-rich angiogenic inducer 61 (CYR61) as a circulating protein biomarker: a pilot study

Lung cancer is the most often diagnosed cancer and the main cause of cancer deaths in the world compared with other tumor entities. To date, the only screening method for high‐risk lung cancer patients is low‐dosed computed tomography which still suffers from high false‐positive rates and overdiagnosis. Therefore, there is an obvious need to identify biomarkers for the detection of lung cancer that could be used to guide the use of low‐dosed computed tomography or other imaging procedures. We aimed to assess the performance of the protein cysteine‐rich angiogenic inducer 61 (CYR61) as a circulating biomarker for the detection of lung cancer. CYR61 concentrations in plasma were significantly elevated in 87 lung cancer patients (13.7 ± 18.6 ng·mL⁻¹) compared with 150 healthy controls (0.29 ± 0.22 ng·mL⁻¹). Subset analysis stratified by sex revealed increased CYR61 concentrations for adenocarcinoma and squamous cell carcinoma in men compared with women. For male lung cancer patients versus male healthy controls, the sensitivity was 84% at a specificity of 100%, whereas for females, the sensitivity was 27% at a specificity of 99%. The determination of circulating CYR61 protein in plasma might improve the detection of lung cancer in men. The findings of this pilot study support further verification of CYR61 as a biomarker for lung cancer detection in men. Additionally, CYR61 is significantly elevated in women but sensitivity and specificity for CYR61 are too low for the improvement of the detection of lung cancer in women.

Re-evaluation of potential predictors of calretinin and mesothelin in a population-based cohort study using assays for the routine application in clinical medicine

OBJECTIVES

Calretinin and mesothelin are molecular markers for the detection of malignant mesothelioma at early stages. Our objective was the re-evaluation of factors influencing calretinin and mesothelin concentrations in plasma of cancer-free men in order to minimise false-positive tests when using commercial assays approved for clinical diagnostics.

SETTING

This re-evaluation used data and archived blood samples of the population-based Heinz Nixdorf Recall Study (HNRS) collected from 2011 to 2014.

PARTICIPANTS

The present analysis comprised of 569 cancer-free men at the time of blood sampling (median age 70 years) from HNRS.

PRIMARY AND SECONDARY OUTCOMES

Mesothelin plasma concentration was determined using ELISA and CLEIA (chemiluminescent enzyme immunoassay). Calretinin plasma concentration was assessed using ELISA.

RESULTS

Compared with the previous determination of concentrations, we detected less false-positive tests using the commercial assays. In this analysis, we found nine false-positive calretinin tests using the ELISA (specificity 98.4%, 95% CI 97.0% to 99.2%) and 24 false-positive mesothelin tests using both ELISA and CLEIA (specificity 95.8%, 95% CI 93.8% to 97.2%). We confirmed renal dysfunction as major predictor of elevated marker concentrations. Mesothelin was additionally affected by bronchitis. Furthermore, elevated inflammation values and hypertension only affected the mesothelin concentration determined by ELISA.

CONCLUSIONS

The newly available assays of calretinin and mesothelin approved for clinical diagnostics showed high specificities in the population-based cohort of elderly men without a malignant disease. The current evaluation provides a basis to consider influencing factors in order to further improve the diagnostic procedure.

Sensitive Blood-Based Detection of Asbestos-Associated Diseases Using Cysteine-Rich Angiogenic Inducer 61 as Circulating Protein Biomarker

BACKGROUND

Detection of asbestos-associated diseases like asbestosis or mesothelioma is still challenging. We sought to improve the diagnosis of benign asbestos-associated disease (BAAD) by detection of the protein cysteine-rich angiogenic inducer 61 (Cyr61) in human plasma.

METHODS

Plasma Cyr61 was quantified using an enzyme-linked immunosorbent assay. Plasma samples from males diagnosed with BAAD, but without a malignant disease (n = 101), and malignant mesothelioma (n = 21; 15 males, 6 females), as well as nonasbestos-exposed healthy control participants (n = 150; 58 males, 92 females) were analyzed. Clinical sensitivity and specificity of Cyr61 were determined by receiver operating characteristic analysis.

RESULTS

The median plasma Cyr61 concentration for healthy control participants was 0.27 ng/mL. Cytoplasmic Cyr61 in peripheral blood mononuclear cells from healthy control participants was evenly distributed, as detected by immunofluorescent staining. The increase in plasma Cyr61 concentrations in the BAAD study group was statistically significant compared to the healthy control participants (P < 0.0001). For the detection of BAAD vs male healthy control participants, clinical sensitivity was 88% and clinical specificity 95% with an area under the curve of 0.924 at maximal Youden Index. For a predefined clinical specificity of 100%, the clinical sensitivity was 76%. For male mesothelioma patients vs male healthy control participants, the clinical sensitivity at maximal Youden Index was 95% with a clinical specificity of 100% (area under the curve, 0.997) and for a predefined clinical specificity of 100%, the clinical sensitivity was 93%.

CONCLUSIONS

In our study, plasma Cyr61 protein concentrations showed to be a new biomarker for asbestos-associated diseases like BAAD and mesothelioma in men, which deserves further investigation in large-scale cohort studies.

Determinants of plasma calretinin in patients with malignant pleural mesothelioma

Objective

Calretinin is a well-known immunohistochemical tissue marker in the diagnosis of malignant mesothelioma. Promising results also indicate the use in early detection. In the present cross-sectional survey, correlations of calretinin plasma levels with clinical features were investigated.

Plasma samples of 60 patients with malignant pleural mesothelioma (MPM) and 111 cancer-free controls formerly exposed to asbestos were compared. Calretinin concentrations were determined in plasma using an enzyme-linked immunosorbent assay (ELISA).

Results

The median concentration was higher in MPM patients than in controls (0.79 vs. 0.23 ng/ml; p < 0.0001). Patients with epithelioid MPM or biphasic MPM had higher calretinin plasma levels than patients with sarcomatoid MPM. Strong expression of calretinin in the tumor tissue was associated with higher plasma levels. Preoperative patients showed higher levels of calretinin than patients after thoracic surgery (1.20 vs. 0.67 ng/ml; p = 0.096). The suitability of plasma calretinin has been confirmed as a tumor marker in the differential diagnosis of epithelioid MPM. The value of plasma calretinin for therapy monitoring or as a prognostic marker should be further investigated.

Circulating long non-coding RNA GAS5 (growth arrest-specific transcript 5) as a complement marker for the detection of malignant mesothelioma using liquid biopsies

Background

For the detection of malignant mesothelioma additional markers are needed besides the established panel consisting of calretinin and mesothelin. The aim of this study was the identification and verification of long non-coding RNAs (lncRNAs) as complementing circulating markers.

Methods

Candidate lncRNAs were identified in silico using previously published RNA expression profiles and verified using quantitative PCR (qPCR) in mesothelioma cell lines as well as human plasma samples from mesothelioma patients and asbestos-exposed controls.

Results

GAS5 (growth arrest-specific transcript 5) as a single marker is marked by a low sensitivity of 14%, but the combination of GAS5 with calretinin and mesothelin increased the panel’s sensitivity from 64 to 73% at a predefined specificity of 97%. Circulating GAS5 is not affected by pleurectomy before blood collection, age, or smoking status.

Conclusions

GAS5 is verified as an appropriate circulating marker for the supplement of calretinin and mesothelin to detect malignant mesothelioma. Although the sensitivity of GAS5 is too low for the use as a single marker, the addition of GAS5 as a third marker improves the performance of the established marker panel. The benefit of GAS5 for the detection of malignant mesothelioma at early stages needs to be validated in a prospective study.

Evaluation of a New Survivin ELISA and UBC® Rapid for the Detection of Bladder Cancer in Urine

Urine-based biomarkers for non-invasive diagnosis of bladder cancer are urgently needed. No single marker with sufficient sensitivity and specificity has been described so far. Thus, a combination of markers appears to be a promising approach. The aim of this case-control study was to evaluate the performance of an in-house developed enzyme-linked immunosorbent assay (ELISA) for survivin, the UBC^®Rapid test, and the combination of both assays. A total of 290 patients were recruited. Due to prior bladder cancer, 46 patients were excluded. Urine samples were available from 111 patients with bladder cancer and 133 clinical controls without urologic diseases. Antibodies generated from recombinant survivin were utilized to develop a sandwich ELISA. The ELISA and the UBC^®Rapid test were applied to all urine samples. Receiver operating characteristic (ROC) analysis was used to evaluate marker performance. The survivin ELISA exhibited a sensitivity of 35% with a specificity of 98%. The UBC^®Rapid test showed a sensitivity of 56% and a specificity of 96%. Combination of both assays increased the sensitivity to 66% with a specificity of 95%. For high-grade tumors, the combination showed a sensitivity of 82% and a specificity of 95%. The new survivin ELISA and the UBC^®Rapid test are both able to detect bladder cancer, especially high-grade tumors. However, the performance of each individual marker is moderate and efforts to improve the survivin assay should be pursued. A combination of both assays confirmed the benefit of using marker panels. The results need further testing in a prospective study and with a high-risk population.

Biomarkers for Predicting Malignant Pleural Mesothelioma in a Mexican Population

Background: Diagnosis of malignant pleural mesothelioma (MPM) remains a challenge, especially when resources in pathology are limited. The study aimed to evaluate cost-effective tumor markers to predict the probability of MPM in plasma samples in order to accelerate the diagnostic workup of the tissue of potential cases. Methods: We conducted a case-control study stratified by gender, which included 75 incident cases with MPM from three Mexican hospitals and 240 controls frequency-matched by age and year of blood drawing. Plasma samples were obtained to determine mesothelin, calretinin, and thrombomodulin using enzyme-linked immunosorbent assays (ELISAs). We estimated the performance of the markers based on the area under the curve (AUC) and predicted the probability of an MPM diagnosis of a potential case based on the marker concentrations. Results: Mesothelin and calretinin, but not thrombomodulin were significant predictors of a diagnosis of MPM with AUCs of 0.90 (95% CI: 0.85-0.95), 0.88 (95% CI: 0.82-0.94), and 0.51 (95% CI: 0.41-0.61) in males, respectively. For MPM diagnosis in men we estimated a true positive rate of 0.79 and a false positive rate of 0.11 for mesothelin. The corresponding figures for calretinin were 0.81 and 0.18, and for both markers combined 0.84 and 0.11, respectively. Conclusions: We developed prediction models based on plasma concentrations of mesothelin and calretinin to estimate the probability of an MPM diagnosis. Both markers showed a good performance and could be used to accelerate the diagnostic workup of tissue samples in Mexico.

Assessment of potential predictors of calretinin and mesothelin to improve the diagnostic performance to detect malignant mesothelioma: results from a population-based cohort study

OBJECTIVES

Mesothelin and calretinin are blood-based markers for malignant mesothelioma. The objective of this study was to analyse the markers in plasma samples from cancer-free men and to identify factors influencing their concentrations to minimise false-positive test results when using these markers for the early detection of malignant mesothelioma.

SETTING

The present analyses used data and archived blood samples of the population-based Heinz Nixdorf Recall Study among elderly people collected from 2011 to 2014.

PARTICIPANTS

A total of 569 men (median age 70 years) without a malignant disease at the time of blood sampling were selected for these analyses.

PRIMARY AND SECONDARY OUTCOME

Mesothelin and calretinin concentration in plasma samples.

RESULTS

We observed 24 mesothelin concentrations ≥1.5 nM (specificity 95.8%, 95% CI 93.8% to 97.2%) and 34 calretinin concentrations ≥1.0 ng/mL (specificity 94.0%, 95% CI 91.7% to 95.7%). Only five men had both markers above these cut-offs. Renal dysfunction and hypertension were major predictors of elevated mesothelin in addition to age. Regarding calretinin, the effect of renal dysfunction was slightly weaker and hypertension was not associated with increased concentrations. However, a diagnosis of cancer after blood collection and bronchial asthma were associated with positive calretinin results.

CONCLUSIONS

The combined determination of mesothelin and calretinin results in only few false-positive marker tests. Both markers are mainly influenced by renal dysfunction. The determination of cystatin C concentrations may be informative when interpreting the test results.

Calretinin as a blood-based biomarker for mesothelioma

Background

Malignant mesothelioma (MM) is a deadly cancer mainly caused by previous exposure to asbestos. With a latency period up to 50 years the incidence of MM is still increasing, even in countries that banned asbestos. Secondary prevention has been established to provide persons at risk regular health examinations. An earlier detection with tumor markers might improve therapeutic options. Previously, we have developed a new blood-based assay for the protein marker calretinin. Aim of this study was the verification of the assay in an independent study population and comparison with the established marker mesothelin.

Methods

For a case-control study in men, a total of 163 cases of pleural MM and 163 controls were available from Australia, another 36 cases and 72 controls were recruited in Germany. All controls had asbestosis and/or plaques. Calretinin and mesothelin were determined by ELISA (enzyme-linked immunosorbent assay) in serum or plasma collected prior to therapy. We estimated the performance of both markers and tested factors potentially influencing marker concentrations like age, sample storage time, and MM subtype.

Results

Calretinin was able to detect all major subtypes except for sarcomatoid MM. Calretinin showed a similar performance in Australian and German men. At a pre-defined specificity of 95% the sensitivity of calretinin reached 71% and that of mesothelin 69%, when excluding sarcomatoid MM. At 97% specificity, the combination with calretinin increased the sensitivity of mesothelin from 66% to 75%. Sample storage time did not influence the results. In controls the concentrations of calretinin increased 1.87-fold (95% CI 1.10–3.20) per 10 years of age and slightly more for mesothelin (2.28, 95% CI 1.30–4.00).

Conclusions

Calretinin could be verified as a blood-based marker for MM. The assay is robust and shows a performance that is comparable to that of mesothelin. Retrospective analyses would not be limited by storage time. The high specificity supports a combination of calretinin with other markers. Calretinin is specific for epithelioid and biphasic MM but not the rarer sarcomatoid form. Molecular markers like calretinin and mesothelin are promising tools to improve and supplement the diagnosis of MM and warrant further validation in a prospective study.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3375-5) contains supplementary material, which is available to authorized users.

A recombinant polypeptide of the megakaryocyte potentiating factor is a potential biomarker in plasma for the detection of mesothelioma

Malignant mesothelioma (MM) is a fatal disease mostly associated with asbestos exposure and difficult to detect by non-invasive methods. This study aimed to use recombinant fragments of the megakaryocyte potentiating factor (MPF) for the development of cost-effective MPF ELISAs. Three polypeptides spanning the MPF region (MPF_1-148, MPF _34-288, MPF/MSLN_254-400) were produced in E.coli as maltose-binding protein hybrids. After isolation, Factor Xa digest, and purification, the polypeptides were used for the generation of rabbit antibodies and development of ELISAs. Forty-one MM patients with known histological subtype before tumor-specific treatment and 70 asbestos-exposed individuals free of any cancer were matched according to age, gender, and smoking. Plasma of all subjects was tested with the three newly developed polyclonal antibody-based ELISAs and a commercial mesothelin assay (MESOMARK™). The latter differentiated patients (median concentration 1.95 nM) from controls (median 1.07 nM, p < 0.0001) and showed an area under curve (AUC) of 0.77 in receiver operating characteristics (ROC) analysis. Of the MPF variants, exclusively the ELISA based on antibodies against the MPF_34-288 fragment displayed significantly (p = 0.0002) higher values in patients than in controls (median 1.61 nM versus 0.88 nM; AUC = 0.72). The combination of the MPF_34-288 and mesothelin displayed an improved ROC performance (AUC = 0.80). The MPF_34-288 ELISA could be a cost-effective and minimal-invasive contribution to support a diagnosis of mesothelioma, especially in regions with a limited medical care.

Combination of MiR-103a-3p and mesothelin improves the biomarker performance of malignant mesothelioma diagnosis

Background

For the detection of malignant mesothelioma no single biomarker with reasonable sensitivity and specificity has been described so far. Mesothelin, the most prominent blood-based biomarker, is characterized by high specificity but low sensitivity. It might be reasonable to combine biomarkers of different molecular classes in order to improve the overall performance. The aim of this study was to assess the performance of the combination of mesothelin and miR-103a-3p as blood-based biomarker for mesothelioma.

Methods/Principal Findings

Mesothelin concentration in plasma and miR-103a-3p levels in the cellular blood fraction were analyzed in 43 male mesothelioma patients and 52 male controls formerly exposed to asbestos. For the discrimination of epithelioid and biphasic mesothelioma from asbestos-exposed controls mesothelin and miR-103a-3p showed 74% and 89% sensitivity and 85% and 63% specificity, respectively. For the combination of mesothelin and miR-103a-3p a sensitivity of 95% and a specificity of 81% were calculated.

Conclusions/Significance

The results of this study show that the combination of mesothelin and miR-103a-3p improves the diagnostic performance of individual blood-based biomarker to detect malignant mesothelioma. The obtained results indicate that the use of biomarkers of different molecular classes might be a reasonable approach to assemble a biomarker panel.

Cross-contamination of a UROtsa stock with T24 cells--molecular comparison of different cell lines and stocks

BACKGROUND

UROtsa is an authentic, immortalized human urothelial cell line that is used to study the effects of metals and other toxic substances, mostly in the context of bladder cancer carcinogenesis. Unusual properties on the molecular level of a provided UROtsa cell line stock prompted us to verify its identity.

METHODS

UROtsa cell line stocks from different sources were tested on several molecular levels and compared with other cell lines. MicroRNA and mRNA expression was determined by Real-Time PCR. Chromosome numbers were checked and PCR of different regions of the large T-antigen was performed. DNA methylation of RARB, PGR, RASSF1, CDH1, FHIT, ESR1, C1QTNF6, PTGS2, SOCS3, MGMT, and LINE1 was analyzed by pyrosequencing and compared with results from the cell lines RT4, T24, HeLa, BEAS-2B, and HepG2. Finally, short tandem repeat (STR) profiling was applied.

RESULTS

All tested UROtsa cell line stocks lacked large T-antigen. STR analysis unequivocally identified our main UROtsa stock as the bladder cancer cell line T24, which was different from two authentic UROtsa stocks that served as controls. Analysis of DNA methylation patterns and RNA expression confirmed their differences. Methylation pattern and mRNA expression of the contaminating T24 cell line showed moderate changes even after long-term culture of up to 56 weeks, whereas miRNAs and chromosome numbers varied markedly.

CONCLUSIONS

It is important to check the identity of cell lines, especially those that are not distributed by major cell banks. However, for some cell lines STR profiles are not available. Therefore, new cell lines should either be submitted to cell banks or at least their STR profile determined and published as part of their initial characterization. Our results should help to improve the identification of UROtsa and other cells on different molecular levels and provide information on the use of urothelial cells for long-term experiments.

Development of an enzyme-linked immunosorbent assay for the detection of human calretinin in plasma and serum of mesothelioma patients

Background

Calretinin is one of the well-established immunohistochemical markers in the diagnostics of malignant mesothelioma (MM). Its utility as a diagnostic tool in human blood, however, is scarcely investigated. The aim of this study was to develop an enzyme-linked immunosorbent assay (ELISA) for human calretinin in blood and to assess its usefulness as a potential minimally invasive diagnostic marker for MM.

Methods

Initially, attempts were made to establish an assay using commercially available antibodies and to optimize it by including a biotin-streptavidin complex into the assay protocol. Subsequently, a novel ELISA based on polyclonal antibodies raised in rabbit immunized with human recombinant calretinin was developed. The assay performance in human serum and plasma (EDTA/heparin) and the influence of calcium concentrations on antibody recognition were studied. Stability of spiked-in calretinin in EDTA plasma under different storage conditions was also examined. In preliminary studies serum and plasma samples from 97 healthy volunteers, 35 asbestos-exposed workers, and 42 MM patients were analyzed.

Results

The mean detection range of the new ELISA was 0.12 to 8.97 ng/ml calretinin. The assay demonstrated markedly lower background and significantly higher sensitivity compared to the initially contrived assay that used commercial antibodies. Recovery rate experiments confirmed dependence of calretinin antibody recognition on calcium concentration. Calcium adjustment is necessary for calretinin measurement in EDTA plasma. Spiked-in calretinin revealed high stability in EDTA plasma when stored at room temperature, 4°C, or after repeated freeze/thaw cycles. Median calretinin values in healthy volunteers, asbestos workers, and MM patients were 0.20, 0.33, and 0.84 ng/ml, respectively (p < 0.0001 for healthy vs. MM, p = 0.0036 for healthy vs. asbestos-exposed, p < 0.0001 for asbestos-exposed vs. MM). Median values in patients with epithelioid and biphasic MM were similar. No influence of age, gender, smoking status, or type of medium (plasma/serum) on calretinin values was found.

Conclusions

The novel assay is highly sensitive and applicable to human serum and plasma. Calretinin appears to be a promising marker for the blood-based detection of MM and might complement other markers. However, further studies are required to prove its usefulness in the diagnosis of MM patients.

A multicentre evaluation of the CA 15-3 assay, CA 19-9 assay and CA 125 II assay on the Bayer Immuno 1 System

The analytical performance of the tumour markers CA 15-3 assay, CA 19-9 assay and Ca 125 II assay on the Bayer Immuno I System was studied according to a revised version of the ECCLS guidelines (Haeckel R. In: Evaluation methods in laboratory medicine, Weinheim, VCH Verlag 1993:47-69) in a multicentre evaluation involving five laboratories. Determination of the 3 analytes generated more than 6000 data. On the Bayer Immuno I System, the imprecisions of the CA 15-3 assay, CA 19-9 assay and CA 125 II assay were better than those found for comparison methods. The median recovery over all five laboratories of system assigned values in control sera was within the 1-s range for the three tumour marker assays. No deviation of linearity could be detected experimentally for all assays. Results for patients' samples showed acceptable agreement between the Bayer Immuno 1 system and several different comparison methods in most cases. One exception was the CA 15-3 assay in comparison with the MCA assay from Roche Diagnostic Systems, where the large difference in values is due to the use of different antibodies and calibrators in the two assays. No carry-over effects could be detected. The selective Bayer Immuno 1 system is fully automated; its practicability was rated as high.