Iron oxide nanoparticles (IONPs) have a great potential with regard to cell labelling, cell tracking, cell separation, magnetic resonance imaging, magnetic hyperthermia, targeted drug and gene delivery. However, a growing body of research has raised concerns about the possible unwanted adverse cytotoxic effects of IONPs. In the present study, the in vitro cellular uptake, antiproliferative activity, cytotoxicity, genotoxicity, prooxidant, microtubule-disrupting and apoptosis-inducing effect of Fe3O4@SiO2 and passivated Fe3O4@SiO2-NH2 nanoparticles on human renal proximal tubule epithelial cells (HK-2) have been studied. Both investigated silica coated IONPs were found to have cell growth-inhibitory activity in a time- and dose-dependent manner. Determination of cell cycle phase distribution by flow cytometry demonstrated a G1 and G2/M phase accumulation of HK-2 cells. A tetrazolium salt cytotoxicity assay at 24 h following treatment demonstrated that cell viability was reduced in a dose-dependent manner. Microscopy observations showed that both Fe3O4@SiO2 and Fe3O4@SiO2-NH2 nanoparticles accumulated in cells and appeared to have microtubule-disrupting activity. Our study also revealed that short term 1 h exposure to 25 and 100 μg/mL of silica coated IONPs causes genotoxicity. Compared with vehicle control cells, a significantly higher amount of γH2AX foci correlating with an increase in DNA double-strand breaks was observed in Fe3O4@SiO2 and Fe3O4@SiO2-NH2-treated and immunestained HK-2 cells. The investigated nanoparticles did not trigger significant ROS generation and apoptosis-mediated cell death. In conclusion, these findings provide new insights into the cytotoxicity of silica coated IONPs that may support their further safer use.

• MeSH
• apoptóza účinky léků   MeSH
• buněčné linie MeSH
• buněčný cyklus účinky léků   MeSH
• dvouřetězcové zlomy DNA MeSH
• epitelové buňky účinky léků   MeSH
• geny p53 MeSH
• histony genetika   MeSH
• lidé MeSH
• magnetické nanočástice toxicita   MeSH
• mikrotubuly účinky léků   MeSH
• oxid křemičitý toxicita   MeSH
• oxid železnato-železitý toxicita   MeSH
• poškození DNA * MeSH
• povrchové vlastnosti MeSH
• proximální tubuly ledvin cytologie   MeSH
• reaktivní formy kyslíku MeSH
• testy genotoxicity MeSH
• virová transformace buněk MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Most of the phosphatases of human fungal pathogens Candida albicans and C. parapsilosis have never been experimentally characterised, although dephosphorylation reactions are central to many biological processes. PHO15 genes of these yeasts have been annotated as the sequences encoding 4-nitrophenyl phosphatase, on the basis of homology to PHO13 gene from the bakers' yeast Saccharomyces cerevisiae. To examine the real function of these potential phosphatases from Candida spp., CaPho15p and CpPho15p were prepared using expression in Escherichia coli and characterised. They share the hallmark motifs of the haloacid dehalogenase superfamily, readily hydrolyse 4-nitrophenyl phosphate at pH 8-8.3 and require divalent cations (Mg2+, Mn2+ or Co2+) as cofactors. CaPho15p and CpPho15p did not dephosphorylate phosphopeptides, but rather hydrolysed molecules related to carbohydrate metabolism. The preferred substrate for the both phosphatases was 2-phosphoglycolate. Among the other molecules tested, CaPho15 showed preference for glyceraldehyde phosphate and ß-glycerol phosphate, while CpPho15 dephosphorylated mainly 1,3-dihydroxyacetone phosphate. This type of substrate specificity indicates that CaPho15 and CpPho15 may be a part of metabolic repair system of C. albicans and C. parapsilosis.

• MeSH
• aminokyselinové motivy MeSH
• biotransformace MeSH
• Candida albicans enzymologie   MeSH
• Candida parapsilosis enzymologie   MeSH
• Escherichia coli genetika   metabolismus   MeSH
• exprese genu MeSH
• fosfatasy genetika   metabolismus   MeSH
• fungální proteiny genetika   metabolismus   MeSH
• glykoláty metabolismus   MeSH
• klonování DNA MeSH
• koenzymy analýza   MeSH
• rekombinantní proteiny genetika   metabolismus   MeSH
• substrátová specifita MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: The search for new anticancer compounds is a crucial element of natural products research. PURPOSE: In this study the effects of naturally occurring homochelidonine in comparison to chelidonine on cell cycle progression and cell death in leukemic T-cells with different p53 status are described. METHODS: The mechanism of cytotoxic, antiproliferative, apoptosis-inducing effects and the effect on expressions of cell cycle regulatory proteins was investigated using XTT assay, Trypan blue exclusion assay, flow cytometry, Western blot analysis, xCELLigence, epi-fluorescence and 3D super resolution microscopy. A549 cells were used for xCELLigence, clonogenic assay and for monitoring microtubule stability. RESULTS: We found that homochelidonine and chelidonine displayed significant cytotoxicity in examined blood cancer cells with the exception of HEL 92.1.7 and U-937 exposed to homochelidonine. Unexpectedly, homochelidonine and chelidonine-induced cytotoxicity was more pronounced in Jurkat cells contrary to MOLT-4 cells. Homochelidonine showed an antiproliferative effect on A549 cells but it was less effective compared to chelidonine. Biphasic dose-depended G1 and G2/M cell cycle arrest along with the population of sub-G1 was found after treatment with homochelidonine in MOLT-4 cells. In variance thereto, an increase in G2/M cells was detected after treatment with homochelidonine in Jurkat cells. Treatment with chelidonine induced cell cycle arrest in the G2/M cell cycle in both MOLT-4 and Jurkat cells. MOLT-4 and Jurkat cells treated with homochelidonine and chelidonine showed features of apoptosis such as phosphatidylserine exposure, a loss of mitochondrial membrane potential and an increase in the caspases -3/7, -8 and -9. Western blots indicate that homochelidonine and chelidonine exposure activates Chk1 and Chk2. Studies conducted with fluorescence microscopy demonstrated that chelidonine and homochelidonine inhibit tubulin polymerization in A549 cells. CONCLUSION: Collectively, the data indicate that chelidonine and homochelidonine are potent inducers of cell death in cancer cell lines, highlighting their potential relevance in leukemic cells.

• MeSH
• apoptóza účinky léků   MeSH
• benzofenantridiny farmakologie   MeSH
• berberinové alkaloidy farmakologie   MeSH
• Chelidonium chemie   MeSH
• Jurkat buňky MeSH
• kaspasy metabolismus   MeSH
• kontrolní body buněčného cyklu účinky léků   MeSH
• lidé MeSH
• membránový potenciál mitochondrií účinky léků   MeSH
• nádorové buněčné linie účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH