Cílem projektu je studium interakce platinových cytostatik s DNA získané z lidských nádorových buněk (buněčné linie včetně chemorezistentních linií, vzorky nádorů získané od pacientů) a studium vlivu metalothioneninů (MT) na tuto interakci. Množství platiny vázané na DNA ovlivňuje účinnost protinádorového účinku platinových cytostatik. K analýze komplexů Pt-DNA a Pt-MT plánujeme využít nově vyvinuté elektrochemické metody. Dále připravíme liposomální transportéry nesoucí platinová cytostatika a rovněž MT nebo zinkové ionty, které ovlivňují odpověď nádorových buněk na platinová cytostatika. Tyto transportéry budeme testovat in vitro a in vivo. Předpokládáme, že naše výsledky a nově vyvinuté techniky zlepší použití platinových cytostatik a přispějí k objasnění mechanismů rezistence k těmto cytostatikům. Dalším přínosem bude zavedení nových elektrochemických metod ke stanovení Pt a její interakce s DNA a MT, které bude použitelné pro klinickou praxi.; The objective of the project is to study the binding of platinum cytostatics to DNA of human tumor cells (cell lines including chemoresistant ones, tumor samples obtained from patients) and the influences of metallothionein (MT) on this interaction. Amounts of platinum bound to DNA influence successfulness of their anticancer effect. Newly developed electrochemical methods, will be used as an analytical tool for study of Pt-DNA and Pt-MT complexes. Liposome based transporter carrying platinum cytostatics, as well as carrying MTs and/or zinc ions that can modulate the response of cancer cells to treatment with platinum cytostatics will be prepared and tested in vitro and in vivo. We assume that our results and developed techniques will improve usage of platinum cytostatics and will help to reveal the mechanisms of resistance to those cytostatics. Another benefit will be the introduction of new electrochemical method for determination of Pt and its interaction with DNA and MT that may be helpful for clinical practice.

• MeSH
• chemorezistence MeSH
• cytostatické látky MeSH
• DNA MeSH
• elektrochemické techniky MeSH
• lidé MeSH
• lyzozomy MeSH
• metalothionein MeSH
• nádory genetika   MeSH
• nanočástice MeSH
• protinádorové látky MeSH
• sloučeniny platiny MeSH
• Check Tag
• lidé MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• onkologie
• genetika, lékařská genetika
• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

Self-propelled microrobots are seen as the next step of micro- and nanotechnology. The biomedical and environmental applications of these robots in the real world need their motion in the confined environments, such as in veins or spaces between the grains of soil. Here, self-propelled trilayer microrobots have been prepared using electrodeposition techniques, coupling unique properties of green bismuth (Bi) with a layered crystal structure, magnetic nickel (Ni), and a catalytic platinum (Pt) layer. These Bi-based microrobots are investigated as active self-propelled platforms that can load, transfer, and release both doxorubicin (DOX), as a widely used anticancer drug, and arsenic (As) and chromium (Cr), as hazardous heavy metals. The significantly high loading capability for such variable cargoes is due to the high surface area provided by the rhombohedral layered crystal structure of bismuth, as well as the defects introduced through the oxide layer formed on the surface of bismuth. The drug release is based on an ultrafast electroreductive mechanism in which the electron injection into microrobots and consequently into the loaded objects causes an electrostatic repulsion between them and thus an ultrafast release of the loaded cargos. Remarkably, we have presented magnetic control of the Bi-based microrobots inside a microfluidic system equipped with an electrochemical setup as a proof-of-concept to demonstrate (i) heavy metals/DOX loading, (ii) a targeted transport system, (iii) the on-demand release mechanism, and (iv) the recovery of the robots for further usage.

• MeSH
• bismut * chemie   toxicita   MeSH
• chrom chemie   toxicita   MeSH
• doxorubicin * chemie   MeSH
• lidé MeSH
• nádory * farmakoterapie   patologie   MeSH
• nanotechnologie trendy   MeSH
• platina chemie   toxicita   MeSH
• protinádorové látky chemie   terapeutické užití   MeSH
• těžké kovy chemie   toxicita   MeSH
• uvolňování léčiv MeSH
• uzavřené prostory MeSH
• Check Tag
• lidé MeSH

Background: Iron oxide nanoparticles (IONs) have been increasingly utilized in a wide spectrum of biomedical applications. Surface coatings of IONs can bestow a number of exceptional properties, including enhanced stability of IONs, increased loading of drugs or their controlled release. Methods: Using two-step sonochemical protocol, IONs were surface-coated with polyoxyethylene stearate, polyvinylpyrrolidone or chitosan for a loading of two distinct topo II poisons (doxorubicin and ellipticine). The cytotoxic behavior was tested in vitro against breast cancer (MDA-MB-231) and healthy epithelial cells (HEK-293 and HBL-100). In addition, biocompatibility studies (hemotoxicity, protein corona formation, binding of third complement component) were performed. Results: Notably, despite surface-coated IONs exhibited only negligible cytotoxicity, upon tethering with topo II poisons, synergistic or additional enhancement of cytotoxicity was found in MDA-MB-231 cells. Pronounced anti-migratory activity, DNA fragmentation, decrease in expression of procaspase-3 and enhancement of p53 expression were further identified upon exposure to surface-coated IONs with tethered doxorubicin and ellipticine. Moreover, surface-coated IONs nanoformulations of topo II poisons exhibited exceptional stability in human plasma with no protein corona and complement 3 binding, and only a mild induction of hemolysis in human red blood cells. Conclusion: The results imply a high potential of an efficient ultrasound-mediated surface functionalization of IONs as delivery vehicles to improve therapeutic efficiency of topo II poisons.

• MeSH
• biokompatibilní potahované materiály chemie   MeSH
• buněčná smrt účinky léků   MeSH
• buněčné linie MeSH
• DNA-topoisomerasy typu II metabolismus   MeSH
• doxorubicin farmakologie   MeSH
• hojení ran účinky léků   MeSH
• inhibitory topoisomerasy II farmakologie   MeSH
• kinetika MeSH
• lidé MeSH
• nanočástice chemie   MeSH
• pohyb buněk účinky léků   MeSH
• povrchové vlastnosti MeSH
• statická elektřina MeSH
• uvolňování léčiv * MeSH
• vibrace ultrazvukové metody   MeSH
• železité sloučeniny chemie   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

The efficiency of cisplatin (CDDP) is significantly hindered by the development of resistance during the treatment course. To gain a detailed understanding of the molecular mechanisms underlying the development of cisplatin resistance, we comparatively analyzed established a CDDP-resistant neuroblastoma cell line (UKF-NB-4CDDP) and its susceptible parental cells (UKF-NB-4). We verified increased chemoresistance of UKF-NB-4CDDP cells by analyzing the viability, induction of apoptosis and clonal efficiency. To shed more light on this phenomenon, we employed custom cDNA microarray (containing 2234 probes) to perform parallel transcriptomic profiling of RNA and identified that 139 genes were significantly up-regulated due to CDDP chemoresistance. The analyses of molecular pathways indicated that the top up-regulation scoring functions were response to stress, abiotic stimulus, regulation of metabolic process, apoptotic processes, regulation of cell proliferation, DNA repair or regulation of catalytic activity, which was also evidenced by analysis of molecular functions revealing up-regulation of genes encoding several proteins with a wide-spectrum of enzymatic activities. Functional analysis using lysosomotropic agents chloroquine and bafilomycin A1 validated their potential to re-sensitize UKF-NB-4CDDP cells to CDDP. Taken together, the identification of alterations in specific genes and pathways that contribute to CDDP chemoresistance may potentially lead to a renewed interest in the development of novel rational therapeutics and prognostic biomarkers for the management of CDDP-resistant neuroblastoma.

• Publikační typ
• časopisecké články MeSH

Cisplatin (CDDP) is a widely used agent in the treatment of neuroblastoma. Unfortunately, the development of acquired chemoresistance limits its clinical use. To gain a detailed understanding of the mechanisms underlying the development of such chemoresistance, we comparatively analyzed established cisplatin-resistant neuroblastoma cell line (UKF-NB-4CDDP) and its sensitive counterpart (UKF-NB-4). First, using viability screenings, we confirmed the decreased sensitivity of tested cells to cisplatin and identified a cross-resistance to carboplatin and oxaliplatin. Then, the proteomic signatures were analyzed using nano liquid chromatography with tandem mass spectrometry. Among the proteins responsible for UKF-NB-4CDDP chemoresistance, ion channels transport family proteins, ATP-binding cassette superfamily proteins (ATP = adenosine triphosphate), solute carrier-mediated trans-membrane transporters, proteasome complex subunits, and V-ATPases were identified. Moreover, we detected markedly higher proteasome activity in UKF-NB-4CDDP cells and a remarkable lysosomal enrichment that can be inhibited by bafilomycin A to sensitize UKF-NB-4CDDP to CDDP. Our results indicate that lysosomal sequestration and proteasome activity may be one of the key mechanisms responsible for intrinsic chemoresistance of neuroblastoma to CDDP.

• MeSH
• apoptóza účinky léků   MeSH
• chemorezistence genetika   MeSH
• cisplatina škodlivé účinky   farmakologie   MeSH
• lidé MeSH
• lyzozomy genetika   MeSH
• nádorové buněčné linie MeSH
• neuroblastom farmakoterapie   genetika   patologie   MeSH
• proliferace buněk účinky léků   MeSH
• proteasomový endopeptidasový komplex genetika   MeSH
• proteomika * MeSH
• regulace genové exprese u nádorů genetika   MeSH
• transkriptom genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Human metallothionein-3 (hMT-3), also known as growth inhibitory factor, is predominantly expressed in the central nervous system. hMT-3 is presumed to participate in the processes of heavy metal detoxification, regulation of metabolism and protection against oxidative damage of free radicals in the central nervous system; thus, it could play important neuromodulatory and neuroprotective roles. However, the primary functions of hMT-3 and the mechanism underlying its multiple functions in neuroblastoma have not been elucidated so far. First, we confirmed relatively high expression of hMT-3 encoding mRNA in biopsies (n= 23) from high-risk neuroblastoma subjects. Therefore, we focused on investigation of the impact of hMT-3 up-regulation inN-Mycamplifying neuroblastoma cells. The differentially up-regulated genes involved in biological pathways related to cellular senescence and cell cycle were identified using electrochemical microarray with consequent bioinformatic processing. Further, as experimental verification of microarray data, the cytotoxicity of the cisplatin (CDDP) was examined in hMT-3 and mock cells by MTT and clonogenic assays. Overall, our data strongly suggest that up-regulation of hMT-3 positively correlates with the genes involved in oncogene-induced senescence (CDKN2BandANAPC5) or apoptosis (CASP4). Moreover, we identified a significant increase in chemoresistance to cisplatin (CDDP) due to hMT-3 up-regulation (24IC50: 7.5vs. 19.8 μg/ml), indicating its multipurpose biological significance.

• Publikační typ
• časopisecké články MeSH

BACKGROUND: Metallothioneins (MTs) constitute a family of evolutionary conserved low molecular weight proteins with small variations in their amino acid sequences. They play a role in the regulation of trace metals metabolism, in the detoxification of heavy metal ions and in mechanisms controlling growth, differentiation and proliferation of cells. OBJECTIVES: The aim of this study was to evaluate the human and rabbit MTs purity and characterization using advanced analytical approaches. Due to the common use of MT from rabbit liver as a model protein, the properties of the rabbit and human MTs were compared. MATERIAL AND METHODS: Capillary electrophoresis (CE), matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and Brdicka reaction were used for human and rabbit MTs characterization. RESULTS: In chip CE analysis, changes in the range of 5-8 kDa corresponding to the MT monomer, as well as some peaks of 13-14 kDa corresponding to dimers in both species, were observed. Using MALDI-MS, rabbit (MT-2D) and human (MT-1A, MT-1G, MT-1G + Cd and MT-2A) MTs were identified. In the Brdicka reaction analysis, a lower concentration of MTs from both organisms coincided with a decrease in the signal corresponding to MT level (Cat2). However, human MT gave higher Cat2 peak than the same concentration (0.025 mg/mL) of rabbit MT. CONCLUSIONS: The applied methods allowed for the characterization of MTs and gave complementary information about MT isoforms. Altered electrochemical activity of human and rabbit MTs, despite the same number of -sulfhydryl (-SH) groups, was observed, which may be due to different availability of MT cysteinyl groups.

• MeSH
• elektroforéza kapilární metody   MeSH
• králíci MeSH
• lidé MeSH
• metalothionein analýza   MeSH
• protein - isoformy MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice metody   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH

Metallothioneins (MTs) belong to a group of small cysteine-rich proteins that are ubiquitous throughout all kingdoms. The main function of MTs is scavenging of free radicals and detoxification and homeostating of heavy metals. In humans, 16 genes localized on chromosome 16 have been identified to encode four MT isoforms labelled by numbers (MT-1-MT-4). MT-2, MT-3 and MT-4 proteins are encoded by a single gene. MT-1 comprises many (sub)isoforms. The known active MT-1 genes are MT-1A, -1B, -1E, -1F, -1G, -1H, -1M and -1X. The rest of the MT-1 genes (MT-1C, -1D, -1I, -1J and -1L) are pseudogenes. The expression and localization of individual MT (sub)isoforms and pseudogenes vary at intra-cellular level and in individual tissues. Changes in MT expression are associated with the process of carcinogenesis of various types of human malignancies, or with a more aggressive phenotype and therapeutic resistance. Hence, MT (sub)isoform profiling status could be utilized for diagnostics and therapy of tumour diseases. This review aims on a comprehensive summary of methods for analysis of MTs at (sub)isoforms levels, their expression in single tumour diseases and strategies how this knowledge can be utilized in anticancer therapy.

• MeSH
• epigeneze genetická MeSH
• lidé MeSH
• metalothionein metabolismus   MeSH
• nádory farmakoterapie   genetika   metabolismus   MeSH
• protein - isoformy MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

• Publikační typ
• abstrakt z konference MeSH

Metallothionein (MT) plays the important role in the detoxification of heavy metals, protection against oxidative compounds and as a prognostic marker in the development of tumors. It is important to find selective, stable and sensitive tools and probes to evaluate the presence of MT in biological fluids or tissues. QDs linked with ligands such as peptides or small molecules are a promising tool for selective, fast, and sensitive tagging and imaging in medicine. In previous findings, the authors proved the possibility of interaction with QDs (particularly with CdTe) and analyzed the stability of the formed complexes between CdTe and MT during incubation over time. Following that, an initial analysis of the interactions between CdTe quantum dots (QDs) and human metallothionein (MT) was performed. Complexes of mercaptosuccinic acid-covered CdTe QDs + MT were investigated using fluorescence intensity changes along a timeline, quenching analysis, stability interpretation based on zeta potential, and quenching intensity. Based on the preliminary results, it appears as though the possible interactions depend on the size of the CdTe QDs. Additionally, the formation of complexes between CdTe and human MT likely depends mostly on structural changes and conformational reorganization rather than on electrostatic interactions. Both types of interactions are responsible for complex creation and stabilization.

• MeSH
• fluorescence MeSH
• fluorescenční spektrometrie MeSH
• kvantové tečky chemie   MeSH
• lidé MeSH
• metalothionein chemie   MeSH
• povrchové vlastnosti MeSH
• sloučeniny kadmia chemie   MeSH
• telur chemie   MeSH
• velikost částic MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH