In response to DNA damage, the histone PARylation factor 1 (HPF1) regulates PARP1/2 activity, facilitating serine ADP-ribosylation of chromatin-associated factors. While PARP1/2 are known for their role in DNA single-strand break repair (SSBR), the significance of HPF1 in this process remains unclear. Here, we investigated the impact of HPF1 deficiency on cellular survival and SSBR following exposure to various genotoxins. We found that HPF1 loss did not generally increase cellular sensitivity to agents that typically induce DNA single-strand breaks (SSBs) repaired by PARP1. SSBR kinetics in HPF1-deficient cells were largely unaffected, though its absence partially influenced the accumulation of SSB intermediates after exposure to specific genotoxins in certain cell lines, likely due to altered ADP-ribosylation of chromatin. Despite reduced serine mono-ADP-ribosylation, HPF1-deficient cells maintained robust poly-ADP-ribosylation at SSB sites, possibly reflecting PARP1 auto-poly-ADP-ribosylation at non-serine residues. Notably, poly-ADP-ribose chains were sufficient to recruit the DNA repair factor XRCC1, which may explain the relatively normal SSBR capacity in HPF1-deficient cells. These findings suggest that HPF1 and histone serine ADP-ribosylation are largely dispensable for PARP1-dependent SSBR in response to genotoxic stress, highlighting the complexity of mechanisms that maintain genomic stability and chromatin remodeling.

• MeSH
• buněčné linie MeSH
• chromatin metabolismus   MeSH
• DNA vazebné proteiny metabolismus   genetika   MeSH
• histony metabolismus   MeSH
• jaderné proteiny metabolismus   genetika   MeSH
• jednořetězcové zlomy DNA * MeSH
• lidé MeSH
• oprava DNA * MeSH
• poly-ADP-ribosylace MeSH
• poly(ADP-ribosa)polymerasa 1 * metabolismus   genetika   MeSH
• poly(ADP-ribosa)polymerasy metabolismus   genetika   MeSH
• protein XRCC1 metabolismus   genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Nonspecific structural chromosomal aberrations (CAs) can be found at around 1% of circulating lymphocytes from healthy individuals but the frequency may be higher after exposure to carcinogenic chemicals or radiation. The frequency of CAs has been measured in occupational monitoring and an increased frequency of CAs has also been associated with cancer risk. Alterations in DNA damage repair and telomere maintenance are thought to contribute to the formation of CAs, which include chromosome type of aberrations and chromatid type of aberrations. In the present study, we used the result of our published genome-wide association studies to extract data on 153 DNA repair genes from 866 nonsmoking persons who had no known occupational exposure to genotoxic substances. Considering an arbitrary cut-off level of P< 5 × 10-3, single nucleotide polymorphisms (SNPs) tagging 22 DNA repair genes were significantly associated with CAs and they remained significant at P < 0.05 when adjustment for multiple comparisons was done by the Binomial Sequential Goodness of Fit test. Nucleotide excision repair pathway genes showed most associations with 6 genes. Among the associated genes were several in which mutations manifest CA phenotype, including Fanconi anemia, WRN, BLM and genes that are important in maintaining genome stability, as well as PARP2 and mismatch repair genes. RPA2 and RPA3 may participate in telomere maintenance through the synthesis of the C strand of telomeres. Errors in NHEJ1 function may lead to translocations. The present results show associations with some genes with known CA phenotype and suggest other pathways with mechanistic rationale for the formation of CAs in healthy nonsmoking population.

• MeSH
• běloši genetika   MeSH
• celogenomová asociační studie MeSH
• chromozomální aberace * MeSH
• DNA vazebné proteiny genetika   MeSH
• dospělí MeSH
• enzymy opravy DNA genetika   MeSH
• helikasy RecQ genetika   MeSH
• helikáza Wernerova syndromu genetika   MeSH
• jednonukleotidový polymorfismus * MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nekuřáci * MeSH
• oprava chybného párování bází DNA genetika   MeSH
• oprava DNA genetika   MeSH
• počítačová simulace MeSH
• poly(ADP-ribosa)polymerasy genetika   MeSH
• replikační protein A genetika   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• zdraví dobrovolníci pro lékařské studie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Slovenská republika MeSH

Accurate copying of DNA during S phase is essential for genome stability and cell viability. During genome duplication, the progression of the DNA replication machinery is challenged by limitations in nucleotide supply and physical barriers in the DNA template that include naturally occurring DNA lesions and secondary structures that are difficult to replicate. To ensure correct and complete replication of the genome, cells have evolved several mechanisms that protect DNA replication forks and thus maintain genome integrity and stability during S phase. One class of enzymes that have recently emerged as important in this process, and therefore as promising targets in anticancer therapy, are the poly(ADP-ribose) polymerases (PARPs). We review here the roles of these enzymes during DNA replication as well as their impact on genome stability and cellular viability in normal and cancer cells.

• MeSH
• aktivace enzymů MeSH
• cílená molekulární terapie MeSH
• lidé MeSH
• multigenová rodina MeSH
• náchylnost k nemoci MeSH
• nestabilita genomu MeSH
• oprava DNA MeSH
• PARP inhibitory farmakologie   terapeutické užití   MeSH
• poly(ADP-ribosa)polymerasy genetika   metabolismus   MeSH
• poškození DNA MeSH
• proliferace buněk MeSH
• protinádorové látky farmakologie   terapeutické užití   MeSH
• replikace DNA MeSH
• S fáze fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Poly(ADP-ribose) is synthesized by PARP enzymes during the repair of stochastic DNA breaks. Surprisingly, however, we show that most if not all endogenous poly(ADP-ribose) is detected in normal S phase cells at sites of DNA replication. This S phase poly(ADP-ribose) does not result from damaged or misincorporated nucleotides or from DNA replication stress. Rather, perturbation of the DNA replication proteins LIG1 or FEN1 increases S phase poly(ADP-ribose) more than 10-fold, implicating unligated Okazaki fragments as the source of S phase PARP activity. Indeed, S phase PARP activity is ablated by suppressing Okazaki fragment formation with emetine, a DNA replication inhibitor that selectively inhibits lagging strand synthesis. Importantly, PARP activation during DNA replication recruits the single-strand break repair protein XRCC1, and human cells lacking PARP activity and/or XRCC1 are hypersensitive to FEN1 perturbation. Collectively, our data indicate that PARP1 is a sensor of unligated Okazaki fragments during DNA replication and facilitates their repair.

• MeSH
• "flap" endonukleasy metabolismus   MeSH
• buněčné linie MeSH
• DNA vazebné proteiny metabolismus   MeSH
• DNA-ligasa ATP metabolismus   MeSH
• DNA genetika   metabolismus   MeSH
• lidé MeSH
• oprava DNA MeSH
• poly(ADP-ribosa)polymerasa 1 metabolismus   MeSH
• poly(ADP-ribosa)polymerasy genetika   metabolismus   MeSH
• polyadenosindifosfátribosa metabolismus   MeSH
• poškození DNA MeSH
• protein XRCC1 metabolismus   MeSH
• replikace DNA fyziologie   MeSH
• S fáze fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• Klíčová slova
• cílená biologická terapie,
• MeSH
• ascites farmakoterapie   terapie   MeSH
• bevacizumab aplikace a dávkování   škodlivé účinky   terapeutické užití   MeSH
• biologická terapie * metody   trendy   využití   MeSH
• financování organizované MeSH
• geny BRCA1 účinky léků   MeSH
• geny BRCA2 účinky léků   MeSH
• gynekologické chirurgické výkony metody   využití   MeSH
• hormony terapeutické užití   MeSH
• lidé MeSH
• mutace genetika   imunologie   účinky léků   MeSH
• nádory vaječníků * farmakoterapie   genetika   chirurgie   MeSH
• PARP inhibitory terapeutické užití   MeSH
• poly(ADP-ribosa)polymerasy genetika   terapeutické užití   účinky léků   MeSH
• protilátky bispecifické terapeutické užití   MeSH
• radioterapie metody   využití   MeSH
• statistika jako téma MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• přehledy 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

Based on a series of basic, preclinical and clinical studies, the Poly (ADP-ribose) Polymerase 1 (PARP1) inhibitor, olaparib, has recently been approved for use in ovarian cancer patients with BRCA1 or BRCA2 mutations. By identifying novel predictive biomarkers of tumour cell sensitivity to olaparib, it is possible that the utility of PARP inhibitors could be extended beyond this patient subgroup. Many of the known genetic determinants of PARP inhibitor response have key roles in DNA damage response (DDR) pathways. Although protein ubiquitylation is known to play an important role in regulating the DDR, the exact mechanisms by which this occurs are not fully understood. Using two parallel RNA interference-based screening approaches, we identified the E3 ubiquitin ligase, CBLC, as a candidate biomarker of response to olaparib. We validated this observation by demonstrating that silencing of CBLC causes increased sensitivity to olaparib in breast cancer cell line models and that defective homologous recombination (HR) DNA repair is the likely cause. This data provides an example of how defects in the ubiquitin machinery have the potential to influence the response of tumour cells to PARP inhibitors.

• MeSH
• časové faktory MeSH
• ftalaziny farmakologie   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nádory prsu farmakoterapie   enzymologie   genetika   patologie   MeSH
• oprava DNA MeSH
• PARP inhibitory farmakologie   MeSH
• piperaziny farmakologie   MeSH
• poly(ADP-ribosa)polymerasy genetika   metabolismus   MeSH
• posttranslační úpravy proteinů MeSH
• protein BRCA2 genetika   metabolismus   MeSH
• protoonkogenní proteiny c-cbl genetika   metabolismus   MeSH
• regulace genové exprese u nádorů MeSH
• rekombinace genetická MeSH
• RNA interference MeSH
• signální transdukce účinky léků   MeSH
• transfekce MeSH
• ubikvitinace MeSH
• viabilita buněk účinky léků   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Vztah zárodečných BRCA-mutací k incidenci ovariálního karcinomu je dobře znám. Celoživotní riziko vzniku karcinomu vaječníků činí u nosiček mutace genu BRCA1 60 % a nosiček mutace genu BRCA2 přibližně 10–20 %. Geny BRCA1 a BRCA2 patří mezi reparační geny, účastní se opravy zlomů dvojité šroubovice DNA prostřednictvím homologní rekombinace. Při jejich mutaci dochází k poruše reparace DNA. Ovariální tumory u pacientek s mutací BRCA mají relativně uniformní chování charakterizované vyšší odpovědí na chemoterapii založenou na platině v první i dalších liniích léčby, delším celkovým přežitím a obvykle i histologií, nejčastěji v podobě high-grade serózního karcinomu. Díky specifiku mutace v BRCA genech 1 a 2 se dostávají u pacientek s ovariálním karcinomem, ale i karcinomem prsu do popředí nové molekuly, a to především inhibitory poly(ADP-ribose) polymerázy (PARP). Inhibice PARP u nádorových buněk s mutacemi BRCA vede k potlačení schopnosti opravy DNA a zlepšení efektu cytotoxické léčby, jsou však účinné i v monoterapii.

Relationship BRCA germline mutations to the incidence of ovarian cancer is well known. The lifetime risk of deve­lopment ovarian cancer is among BRCA1 gene mutation carriers 60 % and of BRCA2 gene mutation carriers around 10–20 %. The genes BRCA1 and BRCA2 belong to group of reparation genes, which participates in the repair of the DNA strand breaks by homologous recombination. Mutation in these cases leads to failure of DNA repair. Ovarian tumors in patients with BRCA mutations are relatively uniform behavior, characterized by higher response rates to platinum-based chemotherapy in the first as well as the other lines of treatment, longer survival, and usually high-grade serous carcinoma histology. In patients with ovarian or breast cancer, due to particularity of mutations in the BRCA genes 1 and 2, new molecules especially inhibitors of poly (ADP- ribose) polymerase (PARP), gets to forefront of the treatment. Inhibition of PARP activity in tumor cells with BRCA mutations leads to the suppression of the ability of DNA repair and improves the effect of cytotoxic treatment, but PARP inhibitors are also effective in monotherapy.

• MeSH
• buněčná smrt genetika   MeSH
• cílená genová oprava MeSH
• dvojitá slepá metoda MeSH
• fyziologie buňky MeSH
• geny BRCA1 * účinky léků   MeSH
• geny BRCA2 * účinky léků   MeSH
• histologie MeSH
• klinické zkoušky, fáze II jako téma MeSH
• kombinovaná farmakoterapie MeSH
• lidé MeSH
• mutace MeSH
• nádory vaječníků * patofyziologie   terapie   MeSH
• PARP inhibitory MeSH
• poly(ADP-ribosa)polymerasy * aplikace a dávkování   genetika   terapeutické užití   MeSH
• poruchy opravy DNA MeSH
• přežití MeSH
• randomizované kontrolované studie jako téma MeSH
• recidiva MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• práce podpořená grantem MeSH

• Klíčová slova
• kaspáza-3, prokaspáza-3, Bax, Bcl-2, PARP, kancerogeneze,
• MeSH
• apoptóza genetika   MeSH
• dospělí MeSH
• financování organizované MeSH
• kaspasa 3 genetika   MeSH
• lidé MeSH
• nádory endometria diagnóza   genetika   patofyziologie   MeSH
• poly(ADP-ribosa)polymerasy analýza   genetika   MeSH
• protein X asociovaný s bcl-2 genetika   MeSH
• testy karcinogenity MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• ženské pohlaví MeSH

Vaccinia virus (VV) is considered to cause lytic infection of most cells, with lysis being regarded equivalent to necrosis. Activation of caspases has not been associated with necrosis. However, we observed the activation and activity of caspases in epithelial cells HeLa G and BSC-40 lytically infected with VV. Using three different flow-cytometric approaches, we characterized the distinct stages of caspase cascade in VV-infected cells: a cleaved, activated form of caspases detected using a fluorescent pan-caspase inhibitor; caspase activity assayed by cleavage of a non-fluorescent substrate into a fluorescent product; caspase-specific cleavage of death substrates characterized by a fluorescent antibody detecting a neo-epitope in cytokeratin-18. All of these approaches yielded an increased fluorescent signal in VV-infected cells compared to mock-infected controls. Additionally, the signal was decreased by the expression of Bcl-2. The cleavage of cytokeratin-18 was confirmed by western blotting, but another key protein involved in apoptosis, PARP, was not cleaved in VV-infected lytic cells. The necrotic phenotype of the cells was confirmed by increased cell membrane permeability and/or decreased mitochondrial membrane potential. In conclusion, our data suggest that VV infection of the epithelial cells HeLa G and BSC-40 initiates the apoptotic program, however, apoptosis is not completed and switches into necrosis.

• MeSH
• aktiny genetika   metabolismus   MeSH
• aktivace enzymů MeSH
• apoptóza MeSH
• Cercopithecus aethiops MeSH
• cytopatogenní efekt virový MeSH
• epitelové buňky cytologie   fyziologie   virologie   MeSH
• fenotyp MeSH
• financování organizované MeSH
• HeLa buňky MeSH
• kaspasy genetika   metabolismus   MeSH
• keratin-18 genetika   metabolismus   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nekróza MeSH
• permeabilita buněčné membrány MeSH
• poly(ADP-ribosa)polymerasy genetika   metabolismus   MeSH
• protoonkogenní proteiny c-bcl-2 genetika   metabolismus   MeSH
• vakcínie patofyziologie   virologie   MeSH
• virus vakcinie fyziologie   růst a vývoj   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH