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Tytuł:
Prognostic significance of p53 protein accumulation in cancer cells obtained from selected group of patients with sporadic colorectal cancer
Autorzy:
Paluszkiewicz, P
Karski, J.
Berbec, H.
Pawlowska-Wakowicz, B.
Cybulski, M.
Karski, M.
Paszkowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/2043897.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
patient
cancer cell
monoclonal antibody
p53 protein
cancer prognosis
immunohistochemistry
sporadic colorectal cancer
accumulation
colorectal cancer
Źródło:
Journal of Applied Genetics; 1999, 40, 2; 135-144
1234-1983
Pojawia się w:
Journal of Applied Genetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
p53 codon 72 polymorphism in cervical cancer patients and healthy women from Poland.
Autorzy:
Dybikowska, Aleksandra
Dettlaff, Agnieszka
Konopa, Krzysztof
Podhajska, Anna
Powiązania:
https://bibliotekanauki.pl/articles/1044272.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
p53 gene
codon 72 polymorphism
cervical carcinoma
Opis:
A polymorphism at codon 72 of gene p53 results in the presence of either arginine or proline at this position. We investigated the distribution of p53 codon 72 polymorphism in cervical cancer patients and a control group of healthy women from Poland. Our results do not confirm the hypothesis that the p53 codon polymorphism could play a role as a factor for squamous carcinoma of the cervix.
Źródło:
Acta Biochimica Polonica; 2000, 47, 4; 1179-1182
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Family with Li-Fraumeni syndrome and no evidence of a germline mutation of the p53 gene or chromosomal aberrations
Autorzy:
Sikorska, A
Traczyk, Z.
Konopka, L.
Fiszer-Maliszewska, L.
Wojciechowska, B.
Pienkowska-Grela, B.
Rygier, J.
Woroniecka, R.
Witkowska, A.
Rusin, M.
Powiązania:
https://bibliotekanauki.pl/articles/2041808.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
germline mutation
Li-Fraumeni syndrome
brain tumour
carcinoma
child
chromosome aberration
cancer
p53 gene
young adult
Źródło:
Journal of Applied Genetics; 2001, 42, 3; 379-384
1234-1983
Pojawia się w:
Journal of Applied Genetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of G arrest on the cytotoxicity of DNA topoisomerase inhibitors toward human carcinoma cells with different p53 status.
Autorzy:
Bozko, Przemyslaw
Larsen, Annette
Raymond, Eric
Skladanowski, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/1043815.pdf
Data publikacji:
2002
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
cytotoxicity
UCN-01
p53
DNA topoisomerase inhibitors
G2 arrest
Opis:
We here report the influence of the cell cycle abrogator UCN-01 on RKO human colon carcinoma cells differing in p53 status following exposure to two DNA damaging agents, the topoisomerase inhibitors etoposide and camptothecin. Cells were treated with the two drugs at the IC90 concentration for 24 h followed by post-incubation in drug-free medium. RKO cells expressing wild-type, functional p53 arrested the cell cycle progression in both the G1 and G2 phases of the cell cycle whereas the RKO/E6 cells, which lack functional p53, only arrested in the G2 phase. Growth-arrested cells did not resume proliferation even after prolonged incubation in drug-free medium (up to 96 h). To evaluate the importance of the cell cycle arrest on cellular survival, a non-toxic dose of UCN-01 (100 nM) was added to the growth-arrested cells. The addition of UCN-01 was accompanied by mitotic entry as revealed by the appearance of condensed chromatin and the MPM-2 phosphoepitope, which is characteristic for mitotic cells. G2 exit and mitotic transit was accompanied by a rapid activation of caspase-3 and apoptotic cell death. The influence of UCN-01 on the long-term cytotoxic effects of the two drugs was also determined. Unexpectedly, abrogation of the G2 arrest had no influence on the overall cytotoxicity of either drug. In contrast, addition of UCN-01 to cisplatin-treated RKO and RKO/E6 cells greatly increased the cytotoxic effects of the alkylating agent. These results strongly suggest that even prolonged cell cycle arrest in the G2 phase of the cell cycle is not necessarily coupled to efficient DNA repair and enhanced cellular survival as generally believed.
Źródło:
Acta Biochimica Polonica; 2002, 49, 1; 109-119
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Advantage of a baculovirus expression system for protein-protein interaction studies. Involvement of posttranslational phosphorylation in the interaction between wt p53 protein and poly(ADP-ribose) polymerase-1
Autorzy:
Schmid, Gerald
Wojciechowski, Jacek
Węsierska-Gądek, Józefa
Powiązania:
https://bibliotekanauki.pl/articles/1041382.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
nucleocytoplasmic shuttling
NES
p53 isomers
p53 stability
cell cycle arrest
2D-PAGE
p53 nuclear export
FACS analysis
p53 pull-down assay
p53 phosphorylation
Opis:
We recently observed an interaction between poly(ADP-ribose) polymerase-1 (PARP-1) and the tumor suppressor p53 protein. However, more extensive studies on both proteins, especially those on characterization of their domains involved in the interaction were difficult due to very low expression levels of p53 in mammalian cells. Therefore, we generated recombinant proteins for such studies. To clarify which domains of human PARP-1 and of human wild-type (wt) p53 were involved in this protein-protein interaction, we generated baculoviral constructs encoding full length or distinct functional domains of both proteins. Full length PARP-1 was simultaneously coexpressed in insect cells with full length wt p53 protein or its distinct truncated fragments and vice versa. Reciprocal immunoprecipitation of Sf9 cell lysates revealed that the central and carboxy-terminal fragments of p53 each were sufficient to confer binding to PARP-1, whereas the amino-terminal part harbouring the transactivation functional domain was dispensable. On the other hand, the amino-terminal and central fragments of PARP-1 were both necessary for complex formation with p53 protein. Since the most important features of p53 protein are regulated by phosphorylation, we addressed the question whether its phosphorylation is essential for the binding between the two proteins. Baculovirally expressed wt p53 was post-translationally modified. At least six distinct p53 isomers were resolved by immunoblotting following two-dimensional separation of baculovirally expressed wt p53 protein. Using specific phospho-serine antibodies, we identified phosphorylation of baculovirally expressed p53 protein at five distinct sites. To define the role of p53 phosphorylation, pull-down assays using untreated and dephosphorylated p53 protein were performed. Dephosphorylated p53 failed to bind PARP-1, indicating that complex formation between the two proteins was regulated by phosphorylation of p53. The marked phosphorylation of p53 at Ser392 observed in unstressed cells suggests that the phosphorylated carboxy-terminal part of p53 undergoes complex formation with PARP-1 resulting in masking of the NES and thereby preventing its export.
Źródło:
Acta Biochimica Polonica; 2005, 52, 3; 713-719
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of aging and oxidative/genotoxic stress on poly(ADP-ribose) polymerase-1 activity in rat brain
Autorzy:
Strosznajder, Robert
Jesko, Henryk
Adamczyk, Agata
Powiązania:
https://bibliotekanauki.pl/articles/1041342.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
aging
poly(ADP-ribosyl)ation
brain
p53 protein
PARP-1
genotoxic stress
oxidative stress
Opis:
Poly(ADP-ribose) polymerase-1 (PARP-1, EC 2.4.2.30), a DNA-bound enzyme, plays a key role in genome stability, but after overactivation can also be responsible for cell death. The aim of the present study was to investigate PARP-1 activity in the hippocampus, brain cortex, striatum and cerebellum in adult (4 months) and aged (24 months) specific pathogen free Wistar rats and to correlate it with PARP-1 protein level and p53 expression. Moreover, the response of PARP-1 in adult and aged hippocampus to oxidative/genotoxic stress was evaluated. Our data indicated a statistically significant enhancement of PARP-1 activity in aged hippocampus and cerebral cortex comparing to adults without statistically significant changes in PARP-1 protein level. The expression of p53 mRNA was elevated in all aged brain parts with the exception of the cerebral cortex. Our data suggest that enhancement of PARP-1 activity and p53 expression in aged brain may indicate higher DNA damage. Our data also indicate that during excessive oxidative/genotoxic stress there is no response of PARP-1 activity in aged hippocampus in contrast to a significant enhancement of PARP-1 activity in adults which may have important consequences for the physiology and pathology of the brain.
Źródło:
Acta Biochimica Polonica; 2005, 52, 4; 909-914
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prospects for p53-based cancer therapy.
Autorzy:
Stokłsa, Tomasz
Gołąb, Jakub
Powiązania:
https://bibliotekanauki.pl/articles/1041406.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
missense mutations
cancer
p53
stress response
small molecule inhibitors
tumor suppressor
Opis:
The p53 tumor suppressor plays the role of a cellular hub which gathers stress signals such as damage to DNA or hypoxia and translates them into a complex response. p53 exerts its action mainly as a potent transcription factor. The two major outcomes of p53 activity are highlighted: cell cycle arrest and apoptosis. During malignant transformation p53 or p53-pathway related molecules are disabled extremely often. Mutations in p53 gene are present in every second human tumor. A mutant form of p53 may not only negate the wild type p53 function but may play additional role in tumor progression. Therefore p53 represents a relatively unique and specific target for anticancer drug design. Current approaches include several different molecules able to restore p53 wild-type conformation and activity. Such small molecule drugs hold great promise in treating human tumors with dysfunction of p53 pathway in the near future.
Źródło:
Acta Biochimica Polonica; 2005, 52, 2; 321-328
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantitative analysis of the level of p53 and p21WAF1 mRNA in human colon cancer HT-29 cells treated with inositol hexaphosphate
Autorzy:
Węglarz, Ludmiła
Molin, Izabela
Orchel, Arkadiusz
Parfiniewicz, Beata
Dzierżewicz, Zofia
Powiązania:
https://bibliotekanauki.pl/articles/1041248.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
p21WAF1
inositol hexaphosphate
RT-PCR
HT-29 cells
p53
Opis:
The aim of this study was to analyze the molecular mechanism of inositol hexaphosphate (InsP6) action through which it may inhibit proliferation of colon cancer cells and cell cycle progression. A kinetic study of p53 and p21WAF1 mRNA increase was performed on human colon cancer HT-29 cells after treatment with 1, 5 and 10 mM InsP6 for 6, 12, 24 and 48 h. Real-time-QPCR based on TaqMan methodology was applied to analyze quantitatively the transcript levels of these genes. The transcription of β-actin and GAPDH genes was assessed in parallel to select the control gene with least variability. The 2-ΔΔCt method was used to analyze the relative changes in gene transcription. InsP6 stimulated p53 and p21WAF1 expression at the mRNA level, with the highest increase in p21WAF1 mRNA occurring at 24 h, i.e., following the highest increase in p53 mRNA observed at 12 h. Based on these studies it may be concluded that the ability of InsP6 to arrest the cell cycle may be mediated by the transcriptional up-regulation of the p53-responsive p21WAF1 gene.
Źródło:
Acta Biochimica Polonica; 2006, 53, 2; 349-356
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rola komórek macierzystych w etiopatogenezie nowotworów ośrodkowego układu nerwowego
Autorzy:
Rieske, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/1061281.pdf
Data publikacji:
2006
Wydawca:
Medical Communications
Tematy:
APC
P53
SHH
WNT
tumor stem cells
nowotworowe komórki macierzyste
Opis:
The paper presents current views concerning the role of stem cells in neoplasia, with particular emphasis of CNS tumors. First, some arguments are presented supporting the thesis that at the first stage of neoplasia, the cellular target for carcinogens are normal stem cells or progenitor cells. Also, discussed are important problems associated with attempts at identification of cellular sources of neoplasms. One of these is the difficulty encountered with distinguishing stem cells and non-differentiated cells. Second, data are presented allowing the conclusion that within neoplastic tissue exist neoplastic stem cells - cells enabling regeneration of this pathological tissue. In the context of discussion concerning the role of stem cells in the pathogenesis of neoplasms, a new theory about physiologic and pathologic role of normal and damaged proteins, e.g. APC, SUFU, EGFR, c-MYC, P53 is presented. Discussed is also the role of proteins controlling modification of chromatin, e.g. the Polycomb protein. These proteins are extremely important for the differentiation process. The paper presents also own preliminary experience with the role of stem cells in the pathogenesis of CNS tumors. Finally, presented are premises providing hope for application of knowledge concerning neoplastic stem cells in designing novel modalities of oncologic therapies. Development of such therapies may be based on the search for chemotherapeutic agents which would selectively eliminate neoplastic stem cells. It is also possible to use normal but genetically modified stem cells to detect neoplastic stem cells and to eliminate them.
W artykule przedstawiono aktualne poglądy na temat udziału komórek macierzystych w nowotworzeniu, ze szczególnym uwzględnieniem nowotworów ośrodkowego układu nerwowego. Po pierwsze przytoczono niektóre argumenty na rzecz tezy, iż komórkowym celem dla karcynogenów na pierwszym etapie nowotworzenia są prawidłowe komórki macierzyste lub komórki progenitorowe. Jednocześnie omówiono istotne problemy, z jakimi wiążą się próby identyfikacji komórkowego źródła nowotworów. Jednym z nich jest problem odróżnienia komórek macierzystych od komórek zróżnicowanych. Po drugie zaprezentowano dane pozwalające stwierdzić, iż w obrębie tkanki nowotworowej bytują komórki macierzyste nowotworu – komórki umożliwiające regenerację tej patologicznej tkanki. W kontekście rozważań dotyczących roli komórek macierzystych w etiopatogenezie nowotworów przedstawiono nową teorię na temat fizjologicznej i patologicznej roli pełnionej przez prawidłowe i uszkodzone białka, takie jak APC, SUFU, EGFR, c-MYC, P53. Omówione także udział w nowotworzeni, białek kontrolujących modyfikację chromatyny jak np. białka Polycomb. Białka te odgrywają niezwykle istotną rolę w czasie różnicowania. W artykule omówiono także pierwsze doświadczenie własne związane z udziałem komórek macierzystych w etiopatogenezie nowotworów OUN. Wreszcie przedstawione zostały przesłanki dające nadzieję na wykorzystanie wiedzy o nowotworowych komórkach macierzystych do projektowania nowych rodzajów terapii przeciwnowotworowej. Opracowywanie tych terapii może być oparte na poszukiwaniu chemioterapeutyków selektywnie eliminujących nowotworowe komórki macierzyste. Możliwe jest również wykorzystanie prawidłowych, ale zmodyfikowanych genetycznie komórek macierzystych do wyśledzenia nowotworowych komórek macierzystych i ich eliminacji.
Źródło:
Aktualności Neurologiczne; 2006, 6, 3; 169-174
1641-9227
2451-0696
Pojawia się w:
Aktualności Neurologiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rola markerów aktywacji płytek krwi u pacjentów po udarze mózgu
The role of platelet activation markers in patient with ischemic stroke
Autorzy:
Gałka, Małgorzata
Powiązania:
https://bibliotekanauki.pl/articles/1061308.pdf
Data publikacji:
2006
Wydawca:
Medical Communications
Tematy:
P-selectin
glycoprotein 53
ischemic stroke
platelet activation
platelet-leukocyte complexes
kompleksy płytkowo-leukocytarne
udar niedokrwienny mózgu
aktywacja płytek
P-selektyna
glikoproteina 53
Opis:
Platelet activation plays an important role in atherothrombotic disease. Several glycoproteins are expressed on the platelet surface during platelet activation. One of them is P-selectin (CD62P), the more important platelet activation marker. P-selectin is transmembrane protein of the α-granules, which is translocated to the cell surface following activation. The interaction between platetel P-selectin and the specific ligand for P-selectin on leukocytes, P-selectin glycoprotein ligand-1 (PSGL-1), resulting in the formation of platelet-leukocyte complexes, and secretion cytokines and chemokines leading to aggravate the inflammatory processes. Glycoprotein 53 (CD63) which is present in lysosomal membranes also translocates to the plasma membrane during platelet activation. Platelet hyperactivation has been reported in patients with ischemic stroke. Several studies have suggested that platelets are excessively activated in the acute and chronic phases after cerebral ischemia. Therefore, finding platelet function test, could be the first step toward identifying patients who would benefit from antiplatelet treatment.
Aktywacja płytek krwi odgrywa istotną rolę w chorobach pochodzenia zakrzepowo-zatorowego. Podczas aktywacji dochodzi na płytkach do ekspresji różnych glikoprotein powierzchniowych. Należy do nich m.in. P-selektyna, jeden z ważniejszych markerów aktywacji płytek. Jest to przezbłonowe białko α-ziarnistości, które w następstwie aktywacji ulega przemieszczeniu na powierzchnię płytek. P-selektyna pośredniczy w interakcji pomiędzy płytkami i leukocytami poprzez specyficzny ligand dla P-selektyny na leukocytach (PSGL-1). Konsekwencją tej reakcji jest tworzenie kompleksów leukocytarno-płytkowych oraz uwalnianie cytokin i chemokin, co prowadzi do nasilenia procesów zapalnych. Glikoproteina GP53 (CD63) jest obecna w błonach lizosomalnych i ulega również przemieszczeniu na powierzchnię błony plazmatycznej podczas aktywacji płytek. Nadmierna aktywność płytek krwi jest obserwowana u pacjentów z udarem niedokrwiennym mózgu. Różne badania wykazały, że płytki krwi wykazują nadmierną aktywację zarówno w ostrej, jak i przewlekłej fazie udaru. Dlatego też odnalezienie testu monitorującego funkcję płytek może okazać się pierwszym krokiem w kierunku identyfikacji pacjentów, którzy mogą osiągnąć korzyści z zastosowania terapii antypłytkowej.
Źródło:
Aktualności Neurologiczne; 2006, 6, 3; 153-158
1641-9227
2451-0696
Pojawia się w:
Aktualności Neurologiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sequence-specific p53 gene damage by chloroacetaldehyde and its repair kinetics in Escherichia coli
Autorzy:
Kowalczyk, Paweł
Cieśla, Jarosław
Saparbaev, Murat
Laval, Jacques
Tudek, Barbara
Powiązania:
https://bibliotekanauki.pl/articles/1041247.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
chloroacetaldehyde
p53
replication
exocyclic DNA adducts
vinyl chloride
LM-PCR
DNA repair
sequence-specific DNA damage
Opis:
Oxidative stress and certain environmental carcinogens, e.g. vinyl chloride and its metabolite chloroacetaldehyde (CAA), introduce promutagenic exocyclic adducts into DNA, among them 1,N6-ethenoadenine (εA), 3,N4-ethenocytosine (εC) and N2,3-ethenoguanine (εG). We studied sequence-specific interaction of the vinyl-chloride metabolite CAA with human p53 gene exons 5-8, using DNA Polymerase Fingerprint Analysis (DPFA), and identified sites of the highest sensitivity. CAA-induced DNA damage was more extensive in p53 regions which revealed secondary structure perturbations, and were localized in regions of mutation hot-spots. These perturbations inhibited DNA synthesis on undamaged template. We also studied the repair kinetics of CAA-induced DNA lesions in E. coli at nucleotide resolution level. A plasmid bearing full length cDNA of human p53 gene was modified in vitro with 360 mM CAA and transformed into E. coli DH5α strain, in which the adaptive response system had been induced by MMS treatment before the cells were made competent. Following transformation, plasmids were re-isolated from transformed cultures 35, 40, 50 min and 1-24 h after transformation, and further subjected to LM-PCR, using ANPG, MUG and Fpg glycosylases to identify the sites of DNA damage. In adaptive response-induced E. coli cells the majority of DNA lesions recognized by ANPG glycosylase were removed from plasmid DNA within 35 min, while MUG glycosylase excised base modifications only within 50 min, both in a sequence-dependent manner. In non-adapted cells resolution of plasmid topological forms was perturbed, suggesting inhibition of one or more bacterial topoisomerases by unrepaired ε-adducts. We also observed delayed consequences of DNA modification with CAA, manifesting as secondary DNA breaks, which appeared 3 h after transformation of damaged DNA into E. coli, and were repaired after 24 h.
Źródło:
Acta Biochimica Polonica; 2006, 53, 2; 337-347
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gamma-radiation-induced ATM-dependent signalling in human T-lymphocyte leukemic cells, MOLT-4
Autorzy:
Tichý, Aleš
Záškodová, Darina
Řezáčová, Martina
Vávrová, Jiřina
Vokurková, Doris
Pejchal, Jaroslav
Vilasová, Zdena
Cerman, Jaroslav
Österreicher, Jan
Powiązania:
https://bibliotekanauki.pl/articles/1041075.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
checkpoint kinase-2
ionizing radiation
p53
ATM kinase
Mdm2
Opis:
ATM kinase (ATM) is essential for activation of cell cycle check points and DNA repair in response to ionizing radiation (IR). In this work we studied the molecular mechanisms regulating DNA repair and cell death in human T-lymphocyte leukemic cells, MOLT-4. Apoptosis was evaluated by flow-cytometric detection of annexin V. Early apoptotic cells were determined as sub-G1 cells and late apoptotic cells were determined as APO2.7-positive ones. Proteins involved in ATM signalling pathway were analysed by Western-blotting. We observed a rapid (0.5 h) phosphorylation of ATM declining after 6 h after irradiation by all the doses studied (1.5, 3.0, and 7.5 Gy). Checkpoint kinase-2 (Chk-2) was also phosphorylated after 0.5 h but its phosphorylated form persisted 4, 2, and 1 h after the doses of 1.5, 3.0, and 7.5 Gy, respectively. The amount of p53 protein and its form phosphorylated on Ser-392 increased 1 h after irradiation (1-10 Gy). The lethal dose of 7.5 Gy caused an immediate induction and phosphorylation of p53 after 0.5 h post-irradiation. At the time of phosphorylation of p53, we found simultaneous phosphorylation of the oncoprotein Mdm2 on Ser-166. Neither ATM nor its downstream targets showed a dose-dependent response after 1 h when irradiated by the doses of 1-10 Gy. MOLT-4 cells were very sensitive to the effect of IR. Even low doses, such as 1.5 Gy, induced apoptosis 16 h after irradiation (evaluated according to the cleavage of nuclear lamin B to a 48-kDa fragment). IR-induced molecular signalling after exposure to all the tested doses was triggered by rapid phosphorylation of ATM and Chk-2. Subsequent induction of p53 protein and its phosphorylation was accompanied by concomitant phosphorylation of its negative regulator, oncoprotein Mdm2, and followed by induction of apoptosis.
Źródło:
Acta Biochimica Polonica; 2007, 54, 2; 281-287
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes in phosphorylation of histone H2A.X and p53 in response of peripheral blood lymphocytes to gamma irradiation
Autorzy:
Vilasová, Zdeňka
Řezáčová, Martina
Vávrová, Jiřina
Tichý, Aleš
Vokurková, Doris
Zoelzer, Friedo
Řeháková, Zuzana
Osterreicher, Jan
Lukášová, Emilie
Powiązania:
https://bibliotekanauki.pl/articles/1040760.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
lymphocyte
ionizing radiation
p53
phytohemagglutinin (PHA)
apoptosis
DNA damage
Opis:
The main aim of this study was to compare the reaction of quiescent and proliferating, i.e. phytohemagglutinin (PHA)-stimulated, human peripheral blood mononuclear cells (PBMCs) to γ-radiation, and analyse changes of proteins related to repair of DNA damage and apoptosis, such as γH2A.X, p53, p53 phosphorylation at serines-15 and -392, and p21 and their dose dependence. Freshly isolated PBMCs in peripheral blood are predominantly quiescent, in G0 phase, and with very low amounts of proteins p53 and p21. Using confocal microscopy we detected dose dependent (0.5-5 Gy) induction of foci containing γH2A.X (1 h after γ-ray exposure), which are formed around radiation-induced double strand breaks of DNA. Apoptosis was detected from 24 h after irradiation by the dose of 4 Gy onwards by Annexin V binding and lamin B cleavage. Seventy two hours after irradiation 70% of CD3+ lymphocytes were A+. Neither increase in p53 nor its phosphorylation on serine-392 after irradiation was detected in these cells. However, massive increase in p21 (cyclin-dependent kinase inhibitor 1A) was detected after irradiation, which can be responsible for late occurrence of apoptosis in these quiescent cells. PHA-stimulation itself (72 h) caused an increase in early apoptosis (A+PI-) in comparison to non-stimulated PBMCs (38% A+ resp. 13.4%). After PHA-stimulation also the amount of γH2A.X, p53, and p21 increased, but no phosphorylation of p53 on serine-392 or -15 was detected. Reaction to γ-radiation was different in PHA-stimulated lymphocytes: the p53 pathway was activated and p53 was phosphorylated on serines-15 and -392 4 h after irradiation by the dose of 4 Gy. Phosphorylation of p53 at serine-15 increased in a dose-dependent manner in the studied dose range 0.2-7.5 Gy. Also the amount of p21 increased after irradiation. Seventy two hours after irradiation of PHA-stimulated CD3+ T lymphocytes by the dose of 4 Gy 65% of cells were A+.
Źródło:
Acta Biochimica Polonica; 2008, 55, 2; 381-390
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Indukowana fenobarbitalem hipermetylacja rejonu promotorowego genu p53 w watrobie szczurow szczepu Wistar
Phenobarbital-induced hypermethylation of the p53 promoter region in the liver of Wistar rats
Autorzy:
Kostka, G
Urbanek-Olejnik, K.
Wiadrowska, B.
Bankowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/876498.pdf
Data publikacji:
2008
Wydawca:
Narodowy Instytut Zdrowia Publicznego. Państwowy Zakład Higieny
Tematy:
zwierzeta doswiadczalne
szczury
watroba
gen p53
hipermetylacja
fenobarbital
synteza DNA
metylotransferaza DNA
metylacja DNA
experimental animal
rat
liver
p53 gene
hypermethylation
phenobarbital
DNA synthesis
DNA methyltransferase
DNA methylation
Opis:
Indukowane niegenotoksycznymi kancerogenami (NGCs) zmiany metylacji DNA rozpatrywane są jako mechanizm ich toksycznego, w tym rakotwórczego działania. Zbadano wpływ fenobarbitalu (PB), na poziom metylacji regionu promotorowego genu p53 w wątrobie szczurów szczepu Wis tar. Zmiany metylacji genu p53 korelowano z syntezą DNA, aktywnością metylotransferaz DNA (DNMTs) oraz z masą wątroby. Samce szczurów szczepu Wistar otrzymywały PB w dawce wynoszącej 98,2 mg/ kg m.c. x dzień-1 jednorazowo, 3-krotnie i 14-krotnie. Wykazano, że PB wywoływał hipermetylację w badanych sekwencjach rejonu promotorowego genu p53. Indukowana PB hipermetylacja genu występowała w przebiegu całego okresu doświadczalnego. Stymulację syntezy DNA, która poprzedzała wzrost masy wątroby oraz indukcję DNMTs, wykazano tylko po 1 i 3 dawkach związku. Kontynuowanie narażenia zwierząt na PB (14 dawek) nie wywoływało zmian w syntezie DNA i aktywności DNMTs w porównaniu do kontroli. Przypuszcza się, że indukowana PB de novo metylacja rejonu promotorowego genu p53, nie była związana z aktywnością DNMTs.
Non-genotoxic carcinogens (NGCs)-induced changes of DNA methylation has been proposed as a mechanism of their toxicity, including carcinogenic action. The effect of phénobarbital (PB), a rodent liver carcinogen on the methylation level of the p53 promoter region in rat liver was studied. Changes in the methylation status of the p53 gene were correlated with changes in DNA synthesis, DNA methyltransferase (DNMTs) activity and liver weight. Male Wistar rats received PB in one, three or fourteen daily oral doses of 92.8 mg/kg b.w. x day-1. We have demonstrated that PB increased the methylation of the p53 gene. Cytosine hypermethylation in the analyzed CpG sites of the p53 gene promoter occurred during the whole period of study. However, an increase in DNA synthesis was only observed after 1 and 3 days of treatment with PB and it preceded liver growth. Treatment of rats with PB for 1 and 3 days also produced an increase in nuclear DNMTs activity. After prolonged administration (14 days), no changes in DNMTs activity nor DNA synthesis were observed. It is proposed that PB- induced de novo methylation of the p53 gene was not associated with DNMTs activity.
Źródło:
Roczniki Państwowego Zakładu Higieny; 2008, 59, 4; 455-465
0035-7715
Pojawia się w:
Roczniki Państwowego Zakładu Higieny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
p53-dependent suppression of the human calcyclin gene (S100A6): the role of Sp1 and of NFκB
Autorzy:
Króliczak, Weronika
Pietrzak, Maciej
Puzianowska-Kuznicka, Monika
Powiązania:
https://bibliotekanauki.pl/articles/1040715.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
gene suppression
wild type and mutant p53
Sp1
calcyclin gene (S100A6)
NFκB
Opis:
Calcyclin (S100A6) is believed to participate in cell cycle control. It was, however, unclear if its expression depends on p53, a key regulator of apoptosis and cell cycle. We therefore performed transcription regulation assays in HeLa cells and found that wild type p53 suppressed the S100A6 promoter up to 12-fold in a dose-dependent manner. In contrast, the well-characterized V143A, R175H, R249S, and L344A p53 mutants cloned from human cancers suppressed this promoter with a 6 to 9-fold lower efficiency. All the sites mediating the p53-dependent suppression were contained in the -167 to +134 fragment of the S100A6 promoter. Separate overexpression of either Sp1 or of NFκB only partially counteracted the p53 inhibitory effect on the S100A6 promoter, while simultaneous overexpression of both these transactivators resulted in a complete abolishment of the p53 inhibitory effect on this promoter. Sp1 and NFκB binding to the probes resembling their putative binding sites present in the S100A6 promoter was decreased in the presence of wild type p53. We propose that the suppression of S100A6 is yet another mechanism by which p53 inhibits proliferation. Insufficient suppression of this gene by p53 mutants could well be responsible for calcyclin overexpression and cell cycle deregulation observed in cancer tissues.
Źródło:
Acta Biochimica Polonica; 2008, 55, 3; 559-570
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
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