Telomere length and TERT polymorphisms as biomarkers in asbestos-related diseases.

BACKGROUND: Asbestos exposure has been proposed as a risk factor for shorter telomere length. The aim of our study was to investigate whether telomere length in leukocytes and hTERT genetic polymorphisms may serve as potential biomarkers for the risk of developing asbestos-related diseases and as biomarkers of progression and chemotherapy response rate in malignant mesothelioma (MM). SUBJECTS AND METHODS: We conducted two retrospective studies. In the first study, a case-control study, telomere length and hTERT polymorphisms were determined in patients with MM, subjects with pleural plaques and controls without the asbestos related disease, who were occupationally exposed to asbestos. In the second study, a longitudinal observational study, telomere length was also determined in samples from MM patients before and after chemotherapy. Telomere length was determined by monochromatic multiplex quantitative polymerase chain reaction (PCR), while competitive allele-specific PCR was used to genotype hTERT rs10069690, rs2736100 and rs2736098. Logistic regression and survival analysis were used in statistical analysis. RESULTS: Patients with MM had shorter telomere length than subjects with pleural plaques (p < 0.001). After adjustment for age, rs2736098 CT, and rs10069690 TT and CT+TT genotypes were significantly associated with a higher risk of MM (padj = 0.023; padj = 0.026 and padj = 0.017), while rs2736100 AA and CA+AA genotypes conferred to a lower risk for MM compared to all other subjects (padj = 0.017, and padj = 0.026). Telomere length was not associated with a response to chemotherapy (p > 0.05) or time to disease progression (p > 0.05). Carriers of one or two polymorphic rs10069690 T alleles had a good response to chemotherapy (p = 0.039, and p = 0.048), these associations remained statistically significant after adjustment for age (padj = 0.019; padj = 0.017). Carriers of two polymorphic rs2736100 A alleles had a longer time to disease progression (p = 0.038). CONCLUSIONS: Shorter telomere length and hTERT polymorphisms may serve as a biomarker for the risk of developing MM. Additionally, rs10069690 and rs2736100 polymorphisms, but not telomere length, were associated with a chemotherapy response or MM progression.

The association of genetic factors with serum calretinin levels in asbestos-related diseases.

BACKGROUND: Asbestos exposure is associated with different asbestos-related diseases, including malignant mesothelioma (MM). MM diagnosis is confirmed with immunohistochemical analysis of several markers, including calretinin. Increased circulating calretinin was also observed in MM. The aim of the study was to determine if CALB2 polymorphisms or polymorphisms in genes that can regulate calretinin expression are associated with serum calretinin levels or MM susceptibility. SUBJECTS AND METHODS: The study included 288 MM patients and 616 occupationally asbestos-exposed subjects without MM (153 with asbestosis, 380 with pleural plaques and 83 without asbestos-related disease). Subjects were genotyped for seven polymorphisms in CALB2, E2F2, MIR335, NRF1 and SEPTIN7 genes using competitive allele-specific polymerase chain reaction (PCR). Serum calretinin was determined with ELISA in 545 subjects. Nonparametric tests, logistic regression and receiver operating characteristic (ROC) curve analysis were used for statistical analysis. RESULTS: Carriers of at least one polymorphic CALB2 rs889704 allele had lower calretinin levels (P = 0.036). Carriers of two polymorphic MIR335 rs3807348 alleles had higher calretinin (P = 0.027), while carriers of at least one polymorphic NRF1 rs13241028 allele had lower calretinin levels (P = 0.034) in subjects without MM. Carriers of two polymorphic E2F2 rs2075995 alleles were less likely to develop MM (odds ratio [OR] = 0.64, 95% confidence interval [CI] = 0.43-0.96, P = 0.032), but the association was no longer significant after adjustment for age (P = 0.093). Optimal serum calretinin cut-off values differentiating MM patients from other subjects differed according to CALB2, NRF1, E2F2, and MIR335 genotypes. CONCLUSIONS: The results of presented study suggest that genetic variability could influence serum calretinin levels. These findings could contribute to a better understanding of calretinin regulation and potentially to earlier MM diagnosis.

Serum Calretinin and Genetic Variability as a Prognostic and Predictive Factor in Malignant Mesothelioma.

Calretinin is a promising diagnostic biomarker for malignant mesothelioma (MM), but less is known about its prognostic role. Our aim was to evaluate the association between serum calretinin concentration or genetic factors and the survival or outcome of cisplatin-based chemotherapy in MM. Our study included 265 MM patients. Serum calretinin concentration was determined using ELISA. Patients were genotyped for seven polymorphisms in CALB2, E2F2, MIR335, NRF1, and SEPTIN7 using competitive allele-specific PCR. Nonparametric tests, logistic regression, and survival analysis were used for statistical analysis. Higher serum calretinin concentration was associated with shorter progression-free (PFS) (HR = 1.18 (1.02-1.37), p = 0.023) and overall survival (OS) (HR = 1.20 (1.03-1.41), p = 0.023), but the association was not significant after adjusting for clinical factors (HR = 1.05 (0.85-1.31), p = 0.653 and HR = 1.06 (0.84-1.34), p = 0.613, respectively). SEPTIN7 rs3801339 and MIR335 rs3807348 were associated with survival even after adjustment (HR = 1.76 (1.17-2.64), p = 0.007 and HR = 0.65 (0.45-0.95), p = 0.028, respectively). Calretinin concentration was higher in patients who progressed after treatment with cisplatin-based chemotherapy (1.68 vs. 0.45 ng/mL, p = 0.001). Calretinin concentration above 0.89 ng/mL was associated with shorter PFS and OS from the start of chemotherapy (HR = 1.88 (1.28-2.77), p = 0.001 and HR = 1.91 (1.22-2.97), p = 0.004, respectively), even after adjusting for clinical factors (p < 0.05). MIR335 rs3807348 was associated with a better response to chemotherapy (OR = 2.69 (1.17-6.18), p = 0.020). We showed that serum calretinin is associated with survival and chemotherapy treatment outcomes in MM and could serve as a predictive biomarker.

Dynamic contrast-enhanced MRI in malignant pleural mesothelioma: prediction of outcome based on DCE-MRI measurements in patients undergoing cytotoxic chemotherapy.

BACKGROUND: The malignant pleural mesothelioma (MPM) response rate to chemotherapy is low. The identification of imaging biomarkers that could help guide the most effective therapy approach for individual patients is highly desirable. Our aim was to investigate the dynamic contrast-enhanced (DCE) MR parameters as predictors for progression-free (PFS) and overall survival (OS) in patients with MPM treated with cisplatin-based chemotherapy. METHODS: Thirty-two consecutive patients with MPM were enrolled in this prospective study. Pretreatment and intratreatment DCE-MRI were scheduled in each patient. The DCE parameters were analyzed using the extended Tofts (ET) and the adiabatic approximation tissue homogeneity (AATH) model. Comparison analysis, logistic regression and ROC analysis were used to identify the predictors for the patient's outcome. RESULTS: Patients with higher pretreatment ET and AATH-calculated Ktrans and ve values had longer OS (P≤.006). Patients with a more prominent reduction in ET-calculated Ktrans and kep values during the early phase of chemotherapy had longer PFS (P =.008). No parameter was identified to predict PFS. Pre-treatment ET-calculated Ktrans was found to be an independent predictive marker for longer OS (P=.02) demonstrating the most favourable discrimination performance compared to other DCE parameters with an estimated sensitivity of 89% and specificity of 78% (AUC 0.9, 95% CI 0.74-0.98, cut off > 0.08 min-1). CONCLUSIONS: In the present study, higher pre-treatment ET-calculated Ktrans values were associated with longer OS. The results suggest that DCE-MRI might provide additional information for identifying MPM patients that may respond to chemotherapy.

Serum Calretinin as a Biomarker in Malignant Mesothelioma.

The early diagnosis of malignant mesothelioma (MM) could improve the prognosis of MM patients. To confirm an MM diagnosis, an immunohistochemical analysis of several tumor tissue markers, including calretinin, is currently required. Our aim is to evaluate serum calretinin as a potential biomarker in asbestos-related diseases, especially in MM. Our study includes 549 subjects: 164 MM patients, 117 subjects with asbestosis, 195 subjects with pleural plaques and 73 occupationally asbestos-exposed subjects without asbestos-related diseases. The serum calretinin concentration was determined with a commercially available enzyme immunoassay. Data on the soluble mesothelin-related peptides (SMRP) concentration are available from previous studies. MM patients had a significantly higher calretinin concentration than subjects without disease, subjects with pleural plaques or subjects with asbestosis (all p < 0.001). The histological type was significantly associated with serum calretinin: patients with sarcomatoid MM had lower calretinin than patients with the epithelioid type (p = 0.001). In a ROC curve analysis, the area under the curve for calretinin concentration predicting MM was 0.826 (95% CI = 0.782-0.869; p < 0.001). At the cutoff value of 0.32 ng/mL, sensitivity was 0.683, while specificity was 0.886. The combination of calretinin and SMRP had the highest predictive value. Calretinin is a useful biomarker that can distinguish MM from other asbestos-related diseases and could, therefore, contribute to an earlier non-invasive diagnosis of MM.

Extracellular Vesicle Enriched miR-625-3p Is Associated with Survival of Malignant Mesothelioma Patients.

Malignant mesothelioma (MM) is characterized by poor prognosis and short survival. Extracellular vesicles (EVs) are membrane-bound particles released from cells into various body fluids, and their molecular composition reflects the characteristics of the origin cell. Blood EVs or their miRNA cargo might serve as new minimally invasive biomarkers that would enable earlier detection of MM or treatment outcome prediction. Our aim was to evaluate miRNAs enriched in serum EVs as potential prognostic biomarkers in MM patients in a pilot longitudinal study. EVs were isolated from serum samples obtained before and after treatment using ultracentrifugation on 20% sucrose cushion. Serum EV-enriched miR-103-3p, miR-126-3p and miR-625-3p were quantified using qPCR. After treatment, expression of miR-625-3p and miR-126-3p significantly increased in MM patients with poor treatment outcome (p = 0.012 and p = 0.036, respectively). A relative increase in miR-625-3p expression after treatment for more than 3.2% was associated with shorter progression-free survival (7.5 vs. 19.4 months, HR = 3.92, 95% CI = 1.20-12.80, p = 0.024) and overall survival (12.5 vs. 49.1 months, HR = 5.45, 95% CI = 1.06-28.11, p = 0.043) of MM patients. Bioinformatic analysis showed enrichment of 33 miR-625-3p targets in eight biological pathways. Serum EV-enriched miR-625-3p could therefore serve as a prognostic biomarker in MM and could contribute to a more personalized treatment.

The role of polymorphisms in glutathione-related genes in asbestos-related diseases.

BACKGROUND: The study investigated the influence of GCLC, GCLM, GSTM1, GSTT1 and GSTP1 polymorphisms, as well as the influence of interactions between polymorphism and interactions between polymorphisms and asbestos exposure, on the risk of developing pleural plaques, asbestosis and malignant mesothelioma (MM). SUBJECTS AND METHODS: The cross sectional study included 940 asbestos-exposed subjects, among them 390 subjects with pleural plaques, 147 subjects with asbestosis, 225 subjects with MM and 178 subjects with no asbestos-related disease. GCLC rs17883901, GCLM rs41303970, GSTM1 null, GSTT1 null, GSTP1 rs1695 and GSTP1 rs1138272 genotypes were determined using PCR based methods. In statistical analysis, logistic regression was used. RESULTS: GSTT1 null genotype was associated with the decreased risk for pleural plaques (OR = 0.63; 95% CI = 0.40-0.98; p = 0.026) and asbestosis (OR = 0.51; 95% CI = 0.28-0.93; p = 0.028), but not for MM. A positive association was found between GSTP1 rs1695 AG + GG vs. AA genotypes for MM when compared to pleural plaques (OR = 1.39; 95% CI = 1.00-1.94; p = 0.049). The interactions between different polymorphisms showed no significant influence on the risk of investigated asbestos-related diseases. The interaction between GSTT1 null polymorphism and asbestos exposure decreased the MM risk (OR = 0.17; 95% CI = 0.03-0.85; p = 0.031). CONCLUSIONS: Our findings suggest that GSTT1 null genotype may be associated with a decreased risk for pleural plaques and asbestosis, may modify the association between asbestos exposure and MM and may consequently act protectively on MM risk. This study also revealed a protective effect of the interaction between GSTP1 rs1695 polymorphism and asbestos exposure on MM risk.

The influence of genetic variability in IL1B and MIR146A on the risk of pleural plaques and malignant mesothelioma.

Background 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 polymorphisms in IL1B and MIR146A genes on the risk of developing pleural plaques and MM. Subjects and methods 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. Results 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). Conclusions Our findings suggest that genetic variability of inflammatory mediator IL-1ß could contribute to the risk of developing MM, but not pleural plaques.

NLRP3 and CARD8 polymorphisms influence risk for asbestos-related diseases.

BACKGROUND: This study aimed to investigate the association between NLRP3 rs35829419 and CARD8 rs2043211 polymorphisms and the risk of developing pleural plaques, asbestosis, and malignant mesothelioma (MM), and to study the influence of the interactions between polymorphisms and asbestos exposure on the risk of developing these diseases. METHODS: The case-control study included 416 subjects with pleural plaques, 160 patients with asbestosis, 154 subjects with MM and 149 subjects with no asbestos disease. The NLRP3 rs35829419 and CARD8 rs2043211 polymorphisms were determined using real-time PCR-based methods. In the statistical analysis, standard descriptive statistics was followed by univariate and multivariate logistic regression modelling. RESULTS: Asbestos exposure (medium and high vs low) was associated with the risk for each studied asbestos-related disease. An increased risk of pleural plaques was found for CARD8 rs2043211 at + TT genotypes (OR = 1.48, 95% CI 1.01-2.16, p = 0.042). When the analysis was performed for MM patients as cases, and pleural plaques patients as controls, a decreased MM risk was observed for carriers of CARD8 rs2043211 TT genotype (OR = 0.52, 95% CI 0.27-1.00, p = 0.049). The interactions between NLRP3 rs35829419 and CARD8 rs2043211 genotypes did not influence the risk of any asbestos-related disease. However, when testing interactions with asbestos exposure, a decreased risk of asbestosis was found for NLRP3 CA+AA genotypes (OR = 0.09, 95% CI 0.01-0.60, p = 0.014). CONCLUSIONS: The results of our study suggest that NLRP3 and CARD8 polymorphisms could affect the risk of asbestos-related diseases.

Evaluation of soluble mesothelin-related peptides and MSLN genetic variability in asbestos-related diseases.

Background 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. Our primary objective was to investigate 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. Subjects and methods 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. Results 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). Conclusions MSLN genetic variability affects serum SMRP levels and was associated with shorter survival of MM patients. Combination of genetic and serum factors could therefore serve as a better diagnostic or prognostic biomarker in MM patients.