[Identifying the Importance of MT-3 Expression for Neuroblastoma Cells]. / Identifikace významu exprese MT-3 pro bunky neuroblastomu.

BACKGROUND: Resistance of cancer cells to cytostatics is caused by a number of mechanisms that are often combined. These include reduced cell entry or increased efflux, increased DNA repair, defects of, apoptotic pathways, increased cytostatic degradation as well as elevated levels of intracellular thiols of glutathione and metallothioneins (MT). It has been reported that high concentrations of thiol groups in the cytoplasm bind platinum alkylation derivatives and chemorezistence is due to the transfer of platinum from the cytostatic to MT, which inactivates them. Because we have shown an increase in MT levels in resistant neuroblastoma (NB) lines, but not in sensitive lines after incubation with platinum cytostatics, we have considered MT-3 for NB cells in our previous studies. METHOD: SiMa NB cell lines transfected with vector containing human MT-3 and GFP or GFP only (control). Expression Microarray Human Cancer 3711 ElectraSense medium density 4 × 2k array slides with 1,609 DNA probes (Custom Array, Bothell, WA, USA), MT-3 expression and most expressed genes validated by real-time polymerase chain reaction. Sensitivity to CDDP (cisplatin) - MTT assay, clonogenicity test, Western blott caspase cleavage and free oxygen radicals fluorescence microscopy after CellROX Deep Red Reagent staining. Levels of MT-3 mRNA in 23 samples of high-risk NB, normal human cortex and bovine adrenal glands were investigated by reverse transcription polymerase chain reaction. RESULTS: Expression microarray showed downregulation 3 and overexpression of 19 genes in MT-3 transfected NB cells. Using gene ontology, over-expressed genes have been shown to drive senescence-induced oncogenes (CDKN2B and ANAPC5), and the genes of glutathione S-transferase M3, caspase 4 and DNAJB6 (chaperone neuronal proteins) were also expressed. We have demonstrated a reduced sensitivity of MT-3 transfected cells to CDDP (24h IC50 of 7.48 ± 0.97 and 19.81 ± 1.2 µg/ml), a higher number of colonies after incubation with CDDP, reduced caspase 3 after incubation with CDDP and lower free oxygen radicals after induction of CDDP. High-grade NB cells expressed MT-3 significantly more than non-tumoral adrenal cells but failed to show a clear relationship to disease course. CONCLUSION: We have demonstrated the relationship between MT-3 and senescence-induced oncogene genes and some other genes relevant to cell fate (glutathione S-transferase M3, caspase 4 and DNAJB6) and a significant proportion of MT-3 on CDDP resistance. High levels of MT-3 in high-risk NB could be one of the causes of frequent relapses in this tumor.Key words: neuroblastoma - metallothionein 3 - chemoresistance The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.This work was supported by AZV CR grant 15- 28334A. Submitted: 17. 2. 2018Accepted: 16. 4. 2018.

[Glycine-N-methyltransferase and Malignant Diseases of the Prostate]. / Glycin-N-metyltransferáza a nádorová onemocnení prostaty.

BACKGROUND: Prostate cancer (PC) constitutes a heterogeneous group of diseases with high prevalence rates that are still increasing, particularly in western countries. Since 1980, prostate specific antigen (PSA) and other diagnostic approaches have been used for PC screening; however, some of these approaches are often deemed painful and cause invasive damage of tissue. Therefore, molecular approaches to PC diagnosis are attracting increasing attention, potentially providing patients with less stressful situations and providing better diagnoses and even prognostic information. Recent metabolomic and genomic studies have suggested that biomolecules can be used as diagnostic or prognostic markers or as targets for the development of novel therapeutic modalities. One of these molecules is glycine-N-methyltransferase (GNMT), an enzyme that plays a pivotal role in the biochemical conversion of glycine to sarcosine. The link between this molecule (encoded by homonymous gene - GNMT) and PC has been confirmed at several levels, and thus GNMT can be considered a promising target for the development of advanced diagnostic and/or prognostic approaches. AIM: The aim of this study was to analyse the physiological role of GNMT and to examine in greater detail its connection with PC at different levels, including gene structure, gene expression, and metabolism, in which GNMT plays an important role, not only in controlling the methylation status of cells, but also the metabolism of folic acid and methionine. Last but not least, we discuss the importance of cellular methylation processes and the link between their aberrations and PC development.Key words: glycine - folic acid - metabolism - methylation - sarcosineThis work was supported by GA CR 16-18917S, League against Cancer Prague (project 2022015) and Czech Ministry of Health - RVO, UH Motol 00064203.The authors declare they have no potential confl icts of interest concerning drugs, products, or services used in the study.The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 9. 2. 2016Accepted: 20. 3. 2016.

[Modern Nanomedicine in Treatment of Lung Carcinomas]. / Moderní nanomedicína v lécbe karcinomu plic.

BACKGROUNDS: Despite the fast development of new effective cytostatics and targeted therapy, the treatment efficiency of lung cancer is still insufficient. The systemic administration of drugs results in a decrease in drug concentrations in tumor site, particularly due to specific extracellular environment in lungs. Nanotransporters could serve as a platform, protecting a drug against these undesired effects, which may enhance its therapeutic index and reduce side effects of a drug. Moreover, nanotechnologies possess the potential to improve the diagnostics of lung cancer, and thus increase a survival rate of oncologic patients. AIM: The presented study is aimed to demonstrate the possibilities provided by nanotechnologies in the field of treatment and diagnostic of lung cancers and discuss the obstacles, which complicate a translation into clinical practice.