Genomic instability is a characteristic of a majority of human malignancies. Chromosomal instability is a common form of genomic instability that can be caused by defects in mitotic checkpoint genes. Chromosomal aberrations in peripheral blood are also indicative of genotoxic exposure and potential cancer risk. We evaluated associations between inherited genetic variants in 33 mitotic checkpoint genes and the frequency of chromosomal aberrations (CAs) in the presence and absence of environmental genotoxic exposure. Associations with both chromosome and chromatid type of aberrations were evaluated in two cohorts of healthy individuals, namely an exposed and a reference group consisting of 607 and 866 individuals, respectively. Binary logistic and linear regression analyses were performed for the association studies. Bonferroni-corrected significant p-value was 5 × 10-4 for 99 tests based on the number of analyzed genes and phenotypes. In the reference group the most prominent associations were found with variants in CCNB1, a master regulator of mitosis, and in genes involved in kinetochore function, including CENPH and TEX14, whereas in the exposed group the main association was found with variants in TTK, also an important gene in kinetochore function. How the identified variants may affect the fidelity of mitotic checkpoint remains to be investigated, however, the present study suggests that genetic variation may partly explain interindividual variation in the formation of CAs.

• MeSH
• chromozomální aberace * MeSH
• chromozomální proteiny, nehistonové genetika   MeSH
• cyklin B1 genetika   MeSH
• cyklin-dependentní kinasy genetika   MeSH
• dospělí MeSH
• frekvence genu MeSH
• jednonukleotidový polymorfismus * MeSH
• kinetochory metabolismus   MeSH
• kohortové studie MeSH
• kontrolní body M fáze buněčného cyklu genetika   MeSH
• kultivované buňky MeSH
• lidé MeSH
• lineární modely MeSH
• odds ratio MeSH
• transkripční faktory genetika   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH

The role of hydrogen sulfide (H2S) is addressed in Xenopuslaevis oocytes. Three enzymes involved in H2S metabolism, cystathionine β-synthase, cystathionine γ-lyase, and 3-mercaptopyruvate sulfurtransferase, were detected in prophase I and metaphase II-arrested oocytes and drove an acceleration of oocyte meiosis resumption when inhibited. Moreover, meiosis resumption is associated with a significant decrease in endogenous H2S. On another hand, a dose-dependent inhibition was obtained using the H2S donor, NaHS (1 and 5 mM). NaHS impaired translation. NaHS did not induce the dissociation of the components of the M-phase promoting factor (MPF), cyclin B and Cdk1, nor directly impacted the MPF activity. However, the M-phase entry induced by microinjection of metaphase II MPF-containing cytoplasm was diminished, suggesting upstream components of the MPF auto-amplification loop were sensitive to H2S. Superoxide dismutase and catalase hindered the effects of NaHS, and this sensitivity was partially dependent on the production of reactive oxygen species (ROS). In contrast to other species, no apoptosis was promoted. These results suggest a contribution of H2S signaling in the timing of amphibian oocytes meiosis resumption.

• MeSH
• apoptóza účinky léků   MeSH
• cyklin B metabolismus   MeSH
• cystathionin-beta-synthasa antagonisté a inhibitory   metabolismus   MeSH
• cystathionin-gama-lyasa antagonisté a inhibitory   metabolismus   MeSH
• cytoplazma metabolismus   MeSH
• faktor podporující zrání metabolismus   MeSH
• fosfatasy cdc25 metabolismus   MeSH
• katalasa metabolismus   MeSH
• meióza účinky léků   MeSH
• metafáze účinky léků   MeSH
• oocyty chemie   enzymologie   metabolismus   MeSH
• profáze meiózy I účinky léků   MeSH
• proteinkinasy metabolismus   MeSH
• proteiny buněčného cyklu metabolismus   MeSH
• proteiny Xenopus metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• sulfan metabolismus   MeSH
• sulfidy metabolismus   farmakologie   MeSH
• sulfurtransferasy antagonisté a inhibitory   metabolismus   MeSH
• superoxiddismutasa metabolismus   MeSH
• viabilita buněk účinky léků   MeSH
• Xenopus laevis MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Double-stranded DNA breaks activate a DNA damage checkpoint in G2 phase to trigger a cell cycle arrest, which can be reversed to allow for recovery. However, damaged G2 cells can also permanently exit the cell cycle, going into senescence or apoptosis, raising the question how an individual cell decides whether to recover or withdraw from the cell cycle. Here we find that the decision to withdraw from the cell cycle in G2 is critically dependent on the progression of DNA repair. We show that delayed processing of double strand breaks through HR-mediated repair results in high levels of resected DNA and enhanced ATR-dependent signalling, allowing p21 to rise to levels at which it drives cell cycle exit. These data imply that cells have the capacity to discriminate breaks that can be repaired from breaks that are difficult to repair at a time when repair is still ongoing.

• MeSH
• ATM protein genetika   metabolismus   MeSH
• buněčné linie MeSH
• časosběrné zobrazování metody   MeSH
• cyklin B1 genetika   metabolismus   MeSH
• fluorescenční mikroskopie MeSH
• HEK293 buňky MeSH
• inhibitor p21 cyklin-dependentní kinasy genetika   metabolismus   MeSH
• kontrolní body fáze G2 buněčného cyklu genetika   MeSH
• lidé MeSH
• oprava DNA genetika   MeSH
• poškození DNA * MeSH
• signální transdukce genetika   MeSH
• stárnutí buněk genetika   MeSH
• zelené fluorescenční proteiny genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• cyklin B MeSH
• dítě MeSH
• Ewingův sarkom genetika   patologie   MeSH
• fúzní onkogenní proteiny genetika   MeSH
• imunohistochemie metody   MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nádorové biomarkery genetika   MeSH
• protoonkogenní proteiny genetika   MeSH
• represorové proteiny genetika   MeSH
• retrospektivní studie MeSH
• sarkom * epidemiologie   genetika   patologie   MeSH
• transkripční faktory genetika   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• práce podpořená grantem MeSH

Auxin steers numerous physiological processes in plants, making the tight control of its endogenous levels and spatiotemporal distribution a necessity. This regulation is achieved by different mechanisms, including auxin biosynthesis, metabolic conversions, degradation, and transport. Here, we introduce cis-cinnamic acid (c-CA) as a novel and unique addition to a small group of endogenous molecules affecting in planta auxin concentrations. c-CA is the photo-isomerization product of the phenylpropanoid pathway intermediate trans-CA (t-CA). When grown on c-CA-containing medium, an evolutionary diverse set of plant species were shown to exhibit phenotypes characteristic for high auxin levels, including inhibition of primary root growth, induction of root hairs, and promotion of adventitious and lateral rooting. By molecular docking and receptor binding assays, we showed that c-CA itself is neither an auxin nor an anti-auxin, and auxin profiling data revealed that c-CA does not significantly interfere with auxin biosynthesis. Single cell-based auxin accumulation assays showed that c-CA, and not t-CA, is a potent inhibitor of auxin efflux. Auxin signaling reporters detected changes in spatiotemporal distribution of the auxin response along the root of c-CA-treated plants, and long-distance auxin transport assays showed no inhibition of rootward auxin transport. Overall, these results suggest that the phenotypes of c-CA-treated plants are the consequence of a local change in auxin accumulation, induced by the inhibition of auxin efflux. This work reveals a novel mechanism how plants may regulate auxin levels and adds a novel, naturally occurring molecule to the chemical toolbox for the studies of auxin homeostasis.

• MeSH
• Arabidopsis účinky léků   růst a vývoj   MeSH
• cinnamáty chemie   metabolismus   farmakologie   MeSH
• cyklin B genetika   metabolismus   MeSH
• geneticky modifikované rostliny MeSH
• isomerie MeSH
• kořeny rostlin účinky léků   růst a vývoj   metabolismus   MeSH
• kyseliny indoloctové metabolismus   MeSH
• mechy účinky léků   růst a vývoj   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• proteiny Qa-SNARE genetika   metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• Selaginellaceae účinky léků   růst a vývoj   MeSH
• signální transdukce MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Hypoxia is a prominent feature of solid tumors, dramatically remodeling microtubule structures and cellular pathways and contributing to paclitaxel resistance. Peloruside A (PLA), a microtubule-targeting agent, has shown promising anti-tumor effects in preclinical studies. Although it has a similar mode of action to paclitaxel, it binds to a distinct site on β-tubulin that differs from the classical taxane site. In this study, we examined the unexplored effects of PLA in hypoxia-conditioned colorectal HCT116 cancer cells. METHODS: Cytotoxicity of PLA was determined by cell proliferation assay. The effects of a pre-exposure to hypoxia on PLA-induced cell cycle alterations and apoptosis were examined by flow cytometry, time-lapse imaging, and western blot analysis of selected markers. The hypoxia effect on stabilization of microtubules by PLA was monitored by an intracellular tubulin polymerization assay. RESULTS: Our findings show that the cytotoxicity of PLA is not altered in hypoxia-conditioned cells compared to paclitaxel and vincristine. Furthermore, hypoxia does not alter PLA-induced microtubule stabilization nor the multinucleation of cells. PLA causes cyclin B1 and G2/M accumulation followed by apoptosis. CONCLUSIONS: The cellular and molecular effects of PLA have been determined in normoxic conditions, but there are no reports of PLA effects in hypoxic cells. Our findings reveal that hypoxia preconditioning does not alter the sensitivity of HCT116 to PLA. GENERAL SIGNIFICANCE: These data report on the cellular and molecular effects of PLA in hypoxia-conditioned cells for the first time, and will encourage further exploration of PLA as a promising anti-tumor agent.

• MeSH
• apoptóza účinky léků   MeSH
• bicyklické sloučeniny heterocyklické farmakologie   MeSH
• buňky HT-29 MeSH
• cyklin B1 metabolismus   MeSH
• HCT116 buňky MeSH
• hypoxie buňky * MeSH
• kontrolní body buněčného cyklu účinky léků   MeSH
• laktony farmakologie   MeSH
• lidé MeSH
• mikrotubuly účinky léků   MeSH
• paclitaxel farmakologie   MeSH
• proliferace buněk účinky léků   MeSH
• protinádorové látky farmakologie   MeSH
• vinkristin farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In response to DNA damage, a cell can be forced to permanently exit the cell cycle and become senescent. Senescence provides an early barrier against tumor development by preventing proliferation of cells with damaged DNA. By studying single cells, we show that Cdk activity persists after DNA damage until terminal cell cycle exit. This low level of Cdk activity not only allows cell cycle progression, but also promotes cell cycle exit at a decision point in G2 phase. We find that residual Cdk1/2 activity is required for efficient p21 production, allowing for nuclear sequestration of Cyclin B1, subsequent APC/CCdh1 -dependent degradation of mitotic inducers and induction of senescence. We suggest that the same activity that triggers mitosis in an unperturbed cell cycle enforces senescence in the presence of DNA damage, ensuring a robust response when most needed.

• MeSH
• analýza jednotlivých buněk MeSH
• buněčné linie MeSH
• chinoliny farmakologie   MeSH
• cyklin B1 genetika   metabolismus   MeSH
• cyklin-dependentní kinasa 2 antagonisté a inhibitory   genetika   metabolismus   MeSH
• epitelové buňky cytologie   účinky léků   enzymologie   MeSH
• etoposid farmakologie   MeSH
• inhibitor p21 cyklin-dependentní kinasy genetika   metabolismus   MeSH
• kadheriny genetika   metabolismus   MeSH
• kontrolní body fáze G2 buněčného cyklu účinky léků   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• osteoblasty cytologie   účinky léků   enzymologie   MeSH
• poškození DNA MeSH
• proteinkinasa CDC2 antagonisté a inhibitory   genetika   metabolismus   MeSH
• pteridiny farmakologie   MeSH
• puriny farmakologie   MeSH
• regulace genové exprese MeSH
• retinální pigmentový epitel cytologie   účinky léků   enzymologie   MeSH
• signální transdukce MeSH
• stárnutí buněk účinky léků   MeSH
• thiazoly farmakologie   MeSH
• velikost buňky MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

We determined expression of 83 long non-coding RNAs (lncRNAs) and identified ZFAS1 to be significantly up-regulated in colorectal cancer (CRC) tissue. In cohort of 119 CRC patients we observed that 111 cases displayed at least two-times higher expression of ZFAS1 in CRC compared to paired normal colorectal tissue (P < 0.0001). By use of CRC cell lines (HCT116+/+, HCT116-/- and DLD-1) we showed, that ZFAS1 silencing decreases proliferation through G1-arrest of cell cycle, and also tumorigenicity of CRC cells. We identified Cyclin-dependent kinase 1 (CDK1) as interacting partner of ZFAS1 by pull-down experiment and RNA immunoprecipitation. Further, we have predicted by bioinformatics approach ZFAS1 to sponge miR-590-3p, which was proved to target CDK1. Levels of CDK1 were not affected by ZFAS1 silencing, but cyclin B1 was decreased in both cell lines. We observed significant increase in p53 levels and PARP cleavage in CRC cell lines after ZFAS1 silencing indicating increase in apoptosis. Our data suggest that ZFAS1 may function as oncogene in CRC by two main actions: (i) via destabilization of p53 and through (ii) interaction with CDK1/cyclin B1 complex leading to cell cycle progression and inhibition of apoptosis. However, molecular mechanisms behind these interactions have to be further clarified.

• MeSH
• apoptóza genetika   MeSH
• buňky HT-29 MeSH
• Caco-2 buňky MeSH
• cyklin B1 genetika   metabolismus   MeSH
• dospělí MeSH
• HCT116 buňky MeSH
• Kaplanův-Meierův odhad MeSH
• kolorektální nádory genetika   metabolismus   patologie   MeSH
• kontrolní body fáze G1 buněčného cyklu genetika   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nádorový supresorový protein p53 genetika   metabolismus   MeSH
• poly(ADP-ribosa)polymerasy genetika   metabolismus   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• proteinkinasa CDC2 genetika   metabolismus   MeSH
• regulace genové exprese u nádorů MeSH
• RNA dlouhá nekódující genetika   metabolismus   MeSH
• RNA interference MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• vazba proteinů MeSH
• western blotting MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Meiotické delenie cicavčích oocytov je fyziologicky zastavené v profáze prvého meiotického delenia (blok v profáze I). Návrat do meiózy sa nazýva znovuzahájenie meiózy. U oocytov je kontrolované cyklín‑dependentnou kinázou 1 (CDK1). Aktivita CDK1 je negatívne regulovaná fosforyláciou na treoníne 14 a tyrozíne 15. Počas bloku v profáze I je CDK1 inaktivovaná, pretože tieto aminokyseliné zvyšky sú fosforylované prostredníctvom Wee1B/Myt1 kináz. Pre znovuzahájenie meiózy musí byť CDK1 aktivovaná a aminokyselinové zvyšky defosforylované pomocou CDC25 fosfatáz. Aktivácia/inaktivácia CDK1 závisí na aktivite regulačných kináz a fosfatáz a rovnako aj ich lokalizácii v oocyte.

Meiotic division in mammalian oocytes is physiologically arrested in prophase of the first meiotic division (prophase I arrest). The reactivation of meiosis is called meiosis resumption. In oocytes it is controlled by cyclin‑dependent kinase 1 (CDK1). Activity of CDK1 is negatively regulated by phosphorylation on threonine 14 and tyrosine 15. During prophase I arrest CDK1 is inactivated, because these amino residues are phosphorylated by Wee1B/Myt1 kinases. For meiosis resumption CDK1 has to be activated and amino residues dephosphorylated by the activation of CDC25 phosphatases. Activation/deactivation of CDK1 depends on activity as well as localization of these regulating kinases and phosphatases in oocytes

• MeSH
• cyklin B1 MeSH
• cyklin-dependentní kinasy MeSH
• lidé MeSH
• meióza * fyziologie   MeSH
• myši MeSH
• oocyty * fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH

Regulation of mRNA translation by cytoplasmic polyadenylation is known to be important for oocyte maturation and further development. This process is generally controlled by phosphorylation of cytoplasmic polyadenylation element binding protein 1 (CPEB1). The aim of this study is to determine the role of Aurora kinase A in CPEB1 phosphorylation and the consequent CPEB1-dependent polyadenylation of maternal mRNAs during mammalian oocyte meiosis. For this purpose, we specifically inhibited Aurora kinase A with MLN8237 during meiotic maturation of porcine oocytes. Using poly(A)-test PCR method, we monitored the effect of Aurora kinase A inhibition on poly(A)-tail extension of long and short cyclin B1 encoding mRNAs as markers of CPEB1-dependent cytoplasmic polyadenylation. Our results show that inhibition of Aurora kinase A activity impairs neither cyclin B1 mRNA polyadenylation nor its translation and that Aurora kinase A is unlikely to be involved in CPEB1 activating phosphorylation.

• MeSH
• aurora kinasa A metabolismus   MeSH
• cyklin B1 genetika   MeSH
• faktory štěpení a polyadenylace mRNA chemie   metabolismus   MeSH
• fosforylace MeSH
• meióza * MeSH
• messenger RNA metabolismus   MeSH
• oocyty enzymologie   metabolismus   MeSH
• polyadenylace MeSH
• Sus scrofa metabolismus   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH