Human plasma is increasingly used for studies of extracellular vesicles (EV) as potential biomarkers. Our aim was to find a simple EV-enrichment method for reliable quantification of EVs in plasma to be used as biomarker of disease. Plasma of ten healthy subjects was processed using sedimentation rate- (sucrose cushion ultracentrifugation-sUC) and size- (size exclusion chromatography-SEC) based methods. According to nanoparticle tracking analysis (NTA), asymmetrical flow field-flow fractionation coupled to detectors (AF4-UV-MALS), transmission electron microscopy, enzyme-linked immunosorbent assay and EV specific miRNA quantification, enrichment of EVs from plasma with sUC method lead to high purity of EVs in the samples. Additionally, sUC EV-enrichment method linked to quantification with NTA or AF4-UV-MALS is repeatable, as the relative standard deviation of EV size measured in independently processed samples from the same plasma source was 5.4% and 2.1% when analyzed by NTA or AF4-UV-MALS, respectively. In conclusion, the sUC EV-enrichment method is compatible with reliable measurement of concentration and size of EVs from plasma and could be used on larger cohorts for biomarker discovery in different diseases.
COBISS.SI-ID: 41337603
Asbestos exposure is associated with the development of pleural plaques as well as malignant mesothelioma (MM). Asbestos fibres activate macrophages, leading to the release of inflammatory mediators including interleukin 1 beta (IL-1ß). The expression of IL-1ß may be influenced by genetic variability of IL1B gene or regulatory microRNAs (miRNAs). This study investigated the effect of IL1B and MIR146A polymorphisms on the risk of developing pleural plaques and MM. In total, 394 patients with pleural plaques, 277 patients with MM, and 175 healthy control subjects were genotyped for IL1B and MIR146A polymorphisms. Logistic regression was used in statistical analysis. We found no association between MIR146A and IL1B genotypes, and the risk of pleural plaques. MIR146A rs2910164 was significantly associated with a decreased risk of MM (OR = 0.31, 95% CI = 0.13-0.73, p = 0.008). Carriers of two polymorphic alleles had a lower risk of developing MM, even after adjustment for gender and age (OR = 0.34, 95% CI = 0.14-0.85, p = 0.020). Among patients with known asbestos exposure, carriers of at least one polymorphic IL1B rs1143623 allele also had a lower risk of MM in multivariable analysis (OR = 0.50, 95% CI = 0.28-0.92, p = 0.025). The interaction between IL1B rs1143623 and IL1B rs1071676 was significantly associated with an increased risk of MM (p = 0.050). Our findings suggest that genetic variability of inflammatory mediator IL-1ß could contribute to the risk of developing MM, but not pleural plaques.
COBISS.SI-ID: 31426819
Malignant mesothelioma (MM) is a rare, but fatal disease with few treatment options. The diagnosis and treatment response are challenging in MM. Therefore, the search for novel diagnostic and prognostic biomarkers is ongoing. The aim of our study was to investigate matrix metalloproteinase 9 (MMP9) as a potential serum biomarker of treatment response and survival in MM. We also investigated the influence of genetic polymorphisms on MMP9 serum levels. We included 110 patients with MM that have been previously genotyped for common MMP9 polymorphisms. Serum samples were collected before treatment, at the end of chemotherapy, and at the time of progression. MMP9 serum levels were measured using enzyme-linked immunosorbent assay kits. The role of serum MMP9 and MMP9 polymorphisms in treatment response was determined using the nonparametric tests and logistic or Cox regression. Median serum MMP9 was 706.7 (499.6-1224.9) ng/ml before treatment, 440.5 (255.9-685.2) ng/ml after chemotherapy, and 502.8 (307.2-851.4) ng/ml at disease progression. After chemotherapy, 87 (79.8%) patients had lower serum MMP9, with the median change of -286.3 (-607.3 to -70.2) ng/ml (P ( 0.001). At disease progression, 47 (65.3%) patients had lower serum MMP9 compared to pretreatment values, with the median change of -163.7 (-466.6 to 108.6) ng/ml (P = 0.001). Patients with higher performance status had higher serum MMP9 before treatment (P = 0.010). Among investigated polymorphisms, only rs17576 was associated with serum MMP9 levels before treatment (P = 0.041). In conclusion, median serum MMP9 levels differed significantly before and after treatment of MM, but failed to reach significance as a standalone biomarker. The contribution of MMP9 serum levels and MMP9 polymorphisms to a composite diagnostic and prognostic biomarker should be further tested.
COBISS.SI-ID: 3235963
Asbestos exposure is associated with increased risk of several diseases, including malignant mesothelioma (MM). Cell surface glycoprotein mesothelin is overexpressed in MM and serum soluble mesothelin-related peptides (SMRP) were already proposed as a diagnostic or prognostic biomarker in MM. However, interindividual variability in serum SMRP levels limits the clinical usefulness. We investigated the influence of MSLN rs1057147 on serum SMRP levels in asbestos-exposed subjects and patients with asbestos-related diseases as well as on survival in MM. Among 782 asbestos-exposed subjects and patients with asbestos-related diseases, 154 had MM. Serum SMRP levels were determined using sandwich enzyme-linked immunosorbent assay. All subjects were genotyped for MSLN rs1057147 polymorphism using competitive allele-specific polymerase chain reaction. Nonparametric tests, logistic and Cox regression were used in statistical analysis to compare different subject groups. MM patients had significantly higher SMRP levels than all other subjects (p(0.001). Compared to wild-type MSLN rs1057147 genotype, both heterozygotes and carriers of two polymorphic alleles had significantly higher SMRP levels among subjects without MM (p(0.001), but not in MM patients (p=0.424). If genotype information was included, specificity of SMRP increased from 88.5% to 92.7% for the optimal cutoff value. Overall survival was significantly shorter in MM patients carrying at least one polymorphic rs1057147 allele (HR=1.72, 95% CI=1.15-2.55, p=0.008). In conclusion, MSLN genetic variability affects serum SMRP levels and is associated with survival of MM patients. Combination of genetic and serum factors could therefore serve as a better diagnostic or prognostic biomarker in MM patients.
COBISS.SI-ID: 34748377
Large interindividual differences in treatment outcome are observed in cancer patients undergoing chemotherapy. Our aim was to develop and validate clinical-pharmacogenetic prediction models of gemcitabine/cisplatin or pemetrexed/cisplatin treatment outcome and develop an algorithm for genotype-based treatment recommendations in malignant mesothelioma (MM). We genotyped 189?MM patients for polymorphisms in gemcitabine, pemetrexed and cisplatin metabolism, transport and drug target genes and DNA repair pathways. To build respective clinical-pharmacogenetic models, pharmacogenetic scores were assigned by rounding regression coefficients. Gemcitabine/cisplatin model was based on training group of 71 patients and included CRP, histological type, performance status, RRM1 rs1042927, ERCC2 rs13181, ERCC1 rs3212986, and XRCC1 rs25487. Patients with higher score had shorter progression-free (PFS) and overall survival (P?(?0.001). This model’s sensitivity was 0.615 and specificity 0.812. In independent validation group of 66 patients the sensitivity and specificity were 0.667 and 0.641, respectively. Pemetrexed/cisplatin model was based on 57 patients and included CRP, MTHFD1 rs2236225, and ABCC2 rs2273697. Patients with higher score had worse response and shorter PFS (P?(?0.001). This model’s sensitivity was 0.750 and specificity 0.607. In independent validation group of 20 patients the sensitivity and specificity were 0.889 and 0.500, respectively. The proposed algorithm based on these models could enable the choice of the most effective chemotherapy for 85.5% of patients and lead to improved treatment outcome in MM.
COBISS.SI-ID: 2641275