Julija Hmeljak

The influence of gemcitabine pathway polymorphisms on treatment outcome in patients with malignant mesothelioma.

Objective Identification of biomarkers that could predict gemcitabine efficacy and toxicity is a key issue in the development of individualized therapy. The aim of our study was to evaluate the influence of gemcitabine pathway polymorphisms on treatment outcome in patients with malignant mesothelioma (MM). Methods In total, 107 patients with MM, treated with gemcitabine-platinum chemotherapy, were genotyped for 11 polymorphisms in deoxycytidine kinase, ribonucleotide reductase M1 (RRM1), and cytidine deaminase genes using KASPar assays. Binary logistic regression was used to evaluate the influence of selected polymorphisms on tumor response and occurrence of treatment-related toxicity, while their influence on survival was estimated by Cox proportional hazards model. A haplotype analysis was carried out to assess the combined effect of RRM1 polymorphisms. Results Deoxycytidine kinase and cytidine deaminase polymorphisms did not influence treatment outcome in patients with MM. In multivariable analysis, RRM1 2927A>C polymorphism significantly decreased overall survival probability [hazard ratio (HR)=2.02; 95% confidence interval (CI)=1.11–3.65; P=0.021]. Two promoter polymorphisms, RRM1 −524T>C and −37C>A, decreased the odds of nausea/vomiting grade≥2 occurrence [odds ratio (OR)=0.25; 95% CI=0.10–0.60; P=0.002 and OR=0.26; 95% CI=0.11–0.63; P=0.003, respectively]. RRM1 TTCCA haplotype was associated with worse tumor response (OR=16.67; 95% CI=2.38–100.00; P=0.004) and worse overall survival (HR=2.97; 95% CI=1.46–6.06; P=0.003) compared with the most frequent TTCAA haplotype, while TCACA haplotype influenced nausea/vomiting grade≥2 occurrence (OR=0.27; 95% CI=0.12–0.60; P=0.001). Conclusion RRM1 polymorphisms as well as haplotypes showed an association with gemcitabine treatment efficacy and toxicity; therefore, they should be validated as potential markers for the prediction of clinical outcome in patients with MM.

The influence of platinum pathway polymorphisms on the outcome in patients with malignant mesothelioma

BACKGROUND Platinum-based therapy is widely used in the treatment of malignant mesothelioma (MM); however, the efficacy and toxicity of platinum agents vary greatly between patients. The aim of our study was to evaluate the influence of platinum pathway polymorphisms on treatment outcome in patients with MM. PATIENTS AND METHODS In total, 133 patients with MM treated with (n = 97) or without (n = 36) platinum-based therapy were genotyped for common XPD, ERCC1, and GSTP1 polymorphisms, as well as for GSTM1 and GSTT1 gene deletion. Haplotype analysis was carried out to assess the combined effect of nucleotide excision repair (NER) polymorphisms. RESULTS GST polymorphisms were not associated with treatment outcome in patients with MM. In the group of platinum-treated patients with MM, ERCC1 8092C/C wild-type genotype significantly influenced progression-free survival (PFS) in multivariable analysis accounting for clinical variables (P = 0.034). XPD 312Asp/Asp and ERCC1 8092C/C wild-type genotypes also increased the odds of treatment-related toxic effects in univariable as well as multivariable analysis. The association of wild-type NER genotypes with better PFS and higher susceptibility to treatment-related toxic effects was confirmed in haplotype analysis. CONCLUSIONS Our results suggest that polymorphisms in NER pathway influence platinum-treatment efficacy and toxicity; therefore, these should be further evaluated as potential markers for the prediction of clinical outcome in patients with MM.

DNA Repair Polymorphisms and Treatment Outcomes of Patients with Malignant Mesothelioma Treated with Gemcitabine-Platinum Combination Chemotherapy

Introduction: Genetic polymorphisms that affect DNA repair capacity can modulate the efficacy and toxicity of cytotoxic agents. Therefore, the aim of our study was to evaluate the influence of genetic variability in DNA repair genes on treatment outcome in patients with malignant mesothelioma (MM) treated with gemcitabine-platinum combination chemotherapy. Methods: In total, 109 patients with MM were genotyped for 10 polymorphisms in XRCC1, NBN, RAD51, and XRCC3 genes. The influence of selected polymorphisms on tumor response and occurrence of treatment-related toxicity was determined by logistic regression analysis, whereas their influence on survival was estimated by Cox proportional hazards model. Results: There were no associations between the investigated polymorphisms and tumor response, but we observed a significant association between XRCC1 399Gln allele and reduced overall survival (hazards ratio = 1.70; 95% confidence interval [CI] 1.06–2.73; p = 0.028). Interaction between XRCC1 399Gln allele and C-reactive protein levels revealed that carriers of at least one XRCC1 399Gln allele with C-reactive protein levels above median had significantly shorter overall survival time compared with other patients (12.9 months versus 25.3 months, log-rank p < 0.001). We also observed an association between XRCC1 399Gln and lower frequency of leukopenia (odds ratio [OR] = 0.25; 95% CI 0.09–0.67; p = 0.006), neutropenia (OR = 0.24; 95% CI 0.09–0.68; p = 0.007), and thrombocytopenia (OR = 0.27; 95% CI 0.09–0.84; p = 0.024). In addition, NBN 3474A>C, XRCC3 -316A>G, and Thr241Met polymorphisms showed significant associations with treatment-related toxicity. Conclusions: Our results support the hypothesis that DNA repair gene polymorphisms, particularly XRCC1 Arg399Gln, may modify the response to gemcitabine-platinum combination chemotherapy and, for the first time, show this effect in patients with MM.

No implication of Simian virus 40 in pathogenesis of malignant pleural mesothelioma in Slovenia

BACKGROUND AND AIM Malignant mesothelioma is predominantly caused by asbestos exposure, although the association of Simian virus 40 in its pathogenesis is currently still under debate. Simian virus 40, a DNA rhesus monkey virus with oncogenic properties, accidentally contaminated early batches of polio vaccine in the 1960s. In the 1990s, viral sequences and proteins were discovered in several human tumors, which triggered research to find a link between Simian virus 40 and human cancers, especially malignant mesothelioma. The aim of our study was to establish an effective laboratory procedure for Simian virus 40 detection and to investigate the presence of Simian virus 40 DNA and small t antigen in mesothelioma samples from Slovenian patients. METHODS AND STUDY DESIGN Paraffin-embedded malignant pleural mesothelioma specimens from 103 Slovenian patients were collected and used for total DNA isolation and real-time polymerase chain reaction for Simian virus 40 small t and large T DNA analysis. Special attention was devoted to primer design, good laboratory practice and polymerase chain reaction contamination prevention. Polymerase chain reaction products were sequenced and BLAST aligned. One 5 microm thick paraffin section from each patients tissue block was stained with hematoxylin and eosin for histological typing and one for immunohistochemical detection of Simian virus 40 small t antigen using a monoclonal antibody against Simian virus 40 (Pab280). SV40-expressing Wi-38 cells were used as positive control in both PCR and immunohistochemistry. RESULTS In real-time polymerase chain reaction analyses, only 4 samples gave products with primer pairs amplifying small t antigen and were inconsistent and poorly reproducible. BLAST alignment showed no homology with any deposited SV40 sequences. No immunopositive staining for SV40 small t antigen was found in any of the samples. CONCLUSIONS We found no evidence of SV40 presence in tissue samples from 103 Slovenian patients with malignant pleural mesothelioma. Asbestos exposure remains the main risk factor for malignant pleural mesothelioma in Slovenia.

Hyaluronic acid stimulates the formation of calcium phosphate on CoCrMo alloy in simulated physiological solution

The behaviour of CoCrMo alloy has been studied in two simulated physiological solutions—NaCl and Hanks’ solutions—each containing the sodium salt of hyaluronic acid. Hyaluronic acid is a component of synovial joint fluid, so the behaviour of orthopaedic alloys in its presence needs to be assessed. Electrochemical methods, X-ray photoelectron spectroscopy and scanning electron microscopy have been used to analyse the composition, thickness and morphology of any layers formed on the alloy. The addition of hyaluronic acid shifts the corrosion potential and increases the value of polarization resistance. The presence of hyaluronic acid in simulated Hanks’ physiological solution stimulates the formation of a calcium phosphate layer, opening up the possibility for tailoring the surface properties of CoCrMo alloy. The viability of human osteoblast-like was determined using the Alamar® Blue Assay, while the osteogenic activity was evaluated by alkaline phosphatase activity. The presence of hyaluronic acid affects the alkaline phosphatase activity.

Presence and role of Simian Virus 40 (SV40) in malignant pleural mesothelioma

Presence and role of Simian Virus 40 (SV40) in malignant pleural mesothelioma Background. Evidence of a possible role of viruses in cancer first emerged in the early 1900s and was confirmed after the discovery of Epstein-Barr virus (EBV) in Burkitts lymphoma cells. Thereafter, several oncogenic viruses and retroviruses were characterised. It is estimated that 15% of human malignancies are of viral aetiology. Oncogenic viruses use different proteins to interfere dramatically with the cellular cell cycle and affect many signalling pathways and checkpoints, causing genomic instability, immunoresistance and immortality. Conclusions. Simian virus 40 (SV40) is a small DNA virus from the genus polyomavirus, closely related to human polyomaviruses John Cunningham virus (JCV) and BK virus (BKV) and is highly oncogenic for rodents. The virus accidentally entered the human population through contaminated early batches of polio vaccine in the 1960s. After the discovery of SV40-like DNA sequences in mesothelioma samples in 1994, a new wave of research started, focusing on the role of SV40 in malignant pleural mesothelioma and human cancer in general. Although the virus is not considered a cancer causing agent for humans, it is thought to have a (not yet defined) role in the development of the malignancy. Further research to better understand the interactions between the virus and the mesothelial cell is still ongoing.

Is survivin expression prognostic or predictive in malignant pleural mesothelioma

Malignant pleural mesothelioma is an incurable cancer strongly associated with asbestos exposure and characterised by poor response to treatment. The inhibitor-of-apoptosis protein family member survivin is involved in apoptosis and proliferation and is expressed in cancer cells only. The aims of the present study were to elucidate whether survivin expression is associated with tumour cell apoptosis and proliferation and to assess the prognostic and predictive value of survivin expression in malignant pleural mesothelioma. Archival pleural mesothelioma tissue samples from 101 patients were immunohistochemically analysed for nuclear expression of survivin, for proliferation with the use of Ki-67 as marker and for apoptosis using active caspase-3 as a marker. Staining results and clinical data were included in a survival analysis. Survivin was highly expressed in tumour cell nuclei in all samples and this correlated positively with both apoptosis and proliferation, but did not have a significant prognostic value. We found significantly higher survivin expression in patients who responded to chemotherapy compared to patients with progressive disease. Survivin expression might contribute to treatment response prediction, but survivin expression in malignant pleural mesothelioma did not have prognostic significance.

Current and Future Management of Malignant Mesothelioma: A Consensus Report from the National Cancer Institute Thoracic Malignancy Steering Committee, International Association for the Study of Lung Cancer, and Mesothelioma Applied Research Foundation

&NA; On March 28–29, 2017, the National Cancer Institute (NCI) Thoracic Malignacy Steering Committee, International Association for the Study of Lung Cancer, and Mesothelioma Applied Research Foundation convened the NCI–International Association for the Study of Lung Cancer–Mesothelioma Applied Research Foundation Mesothelioma Clinical Trials Planning Meeting in Bethesda, Maryland. The goal of the meeting was to bring together lead academicians, clinicians, scientists, and the U.S. Food and Drug Administration to focus on the development of clinical trials for patients in whom malignant pleural mesothelioma has been diagnosed. In light of the discovery of new cancer targets affecting the clinical development of novel agents and immunotherapies in malignant mesothelioma, the objective of this meeting was to assemble a consensus on at least two or three practice‐changing multimodality clinical trials to be conducted through NCIs National Clinical Trials Network.

The Central Role of Survivin in Proliferation and Apoptosis of Malignant Pleural Mesothelioma

Malignant pleural mesothelioma is the most common mesothelial malignancy, which arises from the malignant transformation of mesothelial cells that line the pleural cavity. Malignant pleural mesothelioma is a highly invasive disease with a very long latency and treatment is rarely effective, since only few patients survive more than one year after diagnosis (Carbone et al., 2007). Asbestos, a fibrous mineral widely used throughout the 20th century, has been acknowledged to being the main causative agent (Wagner, 1979).