Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Błasiak, Janusz" wg kryterium: Autor


Tytuł:
Reactive oxygen species in BCR-ABL1-expressing cells - relevance to chronic myeloid leukemia
Autorzy:
Antoszewska-Smith, Joanna
Pawlowska, Elzbieta
Blasiak, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/1038675.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
chronic myeloid leukemia
reactive oxygen species
DNA damage
DNA repair
cancer stem cells
imatinib resistance
Opis:
Chronic myeloid leukemia (CML) results from the t(9;22) reciprocal chromosomal translocation producing the BCR-ABL1 gene, conferring growth and proliferation advantages in the CML cells. CML progresses from chronic, often syndrome-free, to blast phase, fatal if not treated. Although the involvement of BCR-ABL1 in some signaling pathways is considered as the cause of CML, the mechanisms resulting in its progression are not completely known. However, BCR-ABL1 stimulates the production of reactive oxygen species (ROS), which levels increase with CML progression and induce BCR-ABL1 self-mutagenesis. Introducing imatinib and other tyrosine kinase inhibitors (TKIs) to CML therapy radically improved its outcome, but TKIs-resistance became an emerging problem. TKI resistance can be associated with even higher ROS production than in TKI-sensitive cells. Therefore, ROS-induced self-mutagenesis of BCR-ABL1 can be crucial for CML progression and TKI resistance and in this way should be taken into account in therapeutic strategies. As a continuous production of ROS by BCR-ABL1 would lead to its self-destruction and death of CML cells, there must be mechanisms controlling this phenomenon. These can be dependent on DNA repair, which is modulated by BCR-ABL1 and can be different in CML stem and progenitor cells. Altogether, the mechanisms of the involvement of BCR-ABL1 in ROS signaling can be engaged in CML progression and TKI-resistance and warrant further study.
Źródło:
Acta Biochimica Polonica; 2017, 64, 1; 1-10
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mitochondrial mutagenesis in BCR-ABL1-expressing cells sensitive and resistant to imatinib
Autorzy:
Blasiak, Janusz
Hoser, Grazyna
Bialkowska-Warzecha, Jolanta
Pawlowska, Elzbieta
Skorski, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/1038829.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
Imatinib
chronic myeloid leukemia
BCR-ABL1 gene
Opis:
Imatinib revolutionized the treatment of chronic myeloid leukemia (CML) with the expression of the BCR-ABL1 tyrosine kinase, but imatinib resistance is an emerging problem. Imatinib can hinder the inhibitory effects of BCR-ABL1 on mitochondrial apoptotic pathway, so mitochondrial mutagenesis can be important for its action. To explore the mechanisms of imatinib resistance we created a mouse-derived CML model cells consisting of parental 32D cells (P) and cells transfected with the BCR-ABL1 gene (S cells) or its variants with the Y253H or T315I mutations (253 and 315 cells, respectively), conferring resistance to imatinib. A fraction of the S cells was cultured in increasing concentrations of imatinib, acquiring resistance to this drug (AR cells). The 253, 315 and AR cells, in contrast to S cells, displayed resistance to imatinib. We observed that the T315I cells displayed greater extent of H2O2-induced mtDNA damage than their imatinib-sensitive counterparts. No difference in the sensitivity to UV radiation was observed among all the cell lines. A decrease in the extent of H2O2-induced mtDNA damage was observed during a 120-min repair incubation in all cell lines, but it was significant only in imatinib-sensitive and T315I cells. No difference in the copy number of mtDNA and frequency of the 3,867-bp deletion was observed and genotoxic stress induced by H2O2 or UV did not change this relationship. In conclusion, some aspects of mtDNA mutagenesis, including sensitivity to oxidative stress and DNA repair can contribute to imatinib resistance in BCR-ABL1-expressing cells.
Źródło:
Acta Biochimica Polonica; 2016, 63, 2; 365-370
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Expression of RUNX2 and its signaling partners TCF7, FGFR1/2 in cleidocranial dysplasia
Autorzy:
Pawłowska, Elżbieta
Wójcik, Katarzyna
Synowiec, Ewelina
Szczepańska, Joanna
Błasiak, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/1039147.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
RUNX2
Wnt signaling
TCF7
fibroblast growth factor signaling
FGFR1
FGFR2
Opis:
RUNX2 is a member of the PEBP2/CBF transcription factors family controlling the expression of genes whose products are essential for bone formation. Mutations in the RUNX2 gene may be associated with cleidocranial dysplasia (CCD), a rare skeletal disease characterized by stature aberrations, delayed closure of the cranial sutures, hypoplastic or aplastic clavicles, and multiple dental abnormalities. As RUNX2 is involved in many signaling pathways, we hypothesize that CCD may be associated with their changes. We determined the expression of RUNX2 and its signaling partners TCF7, involved in canonical Wnt signaling, and fibroblast growth factor receptors, FGFR1 and FGFR2 in periodontum of CCD patients and control individuals. We did not observe any differences between the level of RUNX2, TCF7 and FGFR1/2 mRNA, determined by real-time PCR, in CDD patients and controls. Therefore, RUNX2 signaling pathways with their partners TCF7 and FGFR1/2 may not be involved in CCD pathogenesis.
Źródło:
Acta Biochimica Polonica; 2015, 62, 1; 123-126
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transferrin receptor levels and polymorphism of its gene in age-related macular degeneration
Autorzy:
Wysokinski, Daniel
Danisz, Katarzyna
Pawlowska, Elzbieta
Dorecka, Mariola
Romaniuk, Dorota
Robaszkiewicz, Jacek
Szaflik, Marta
Szaflik, Jerzy
Blasiak, Janusz
Szaflik, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/1039085.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
AMD
gene polymorphism
iron
oxidative stress
TFRC
transferrin receptor
Opis:
The aim of the present study was to investigate the association of age related macular degeneration (AMD) risk with some aspects of iron homeostasis: iron concentration in serum, level of soluble transferrin receptor (sTfR), and transferrin receptor (TFRC) genetic variability. Four hundred and ninety one AMD patients and 171 controls were enrolled in the study. Restriction fragment length polymorphism PCR was employed to genotype polymorphisms of the TFRC gene, and colorimetric assays were used to determine the level of iron and sTfR. Multiple logistic regression was applied for all genotype/allele-related analyses and the ANOVA test for iron and sTfR serum level comparison. We found that the genotypes and alleles of the c.-253G > A polymorphism of the TFRC gene were associated with AMD risk and this association was modulated by smoking status, AMD family history, living environment (rural/urban), body mass index and age. The levels of sTfR was higher in AMD patients than controls, whereas concentrations of iron did not differ in these two groups. No association was found between AMD occurrence and the p.Gly142Ser polymorphism of the TRFC gene. The results obtained suggest that transferrin receptor and variability of its gene may influence AMD risk.
Źródło:
Acta Biochimica Polonica; 2015, 62, 2; 177-184
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Role of biochemical factors in the pathogenesis of keratoconus
Autorzy:
Wojcik, Katarzyna
Blasiak, Janusz
Szaflik, Jerzy
Szaflik, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/1039330.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
keratoconus
cornea
collagen
proteinases
proinflammatory markers
antioxidants
Opis:
Keratoconus (KC) is a corneal disease associated with structural abnormalities in the corneal epithelium, Bowman's layer and stroma and altered concentration of tear components. KC corneas show a different pattern of collagen lamellae than their normal counterparts. Also, a reduction of several collagen types in KC epithelium and stroma was observed. Altered expression and/or activity of lysyl oxidase, a critical enzyme of the biogenesis of connective tissue detected in KC corneas, may weaken covalent bonds between collagen and elastin fibrils, what may lead to biomechanical deterioration of the cornea. Increased activity of matrix metalloproteinases observed in KC may induce the degradation of the extracellular matrix causing damage to the cornea. Oxidative and nitrative stress play an important role in KC pathogenesis and KC corneas are characterized by the disturbed lipid peroxidation and nitric oxide pathways. Malfunctioning of these pathways may lead to accumulation of their toxic by-products inducing several detrimental effects, along with apoptosis of the corneal cells, which may result from the loss of β-actin or increased levels of cytokines, including interleukin-1 and -6. Change in the expression of genes associated with wound healing, including the nerve growth factor and the visual system homeobox 1, may contribute to increased susceptibility of KC corneas to injury. Consequently, biochemical changes may play an important role in KC pathophysiology and, therefore, can be considered in prevention, diagnosis, prognosis and in the therapy of this disease as well.
Źródło:
Acta Biochimica Polonica; 2014, 61, 1; 55-62
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Role of mitochondria in carcinogenesis
Autorzy:
Tokarz, Paulina
Blasiak, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/1039194.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
cancer
mitochondria
mtDNA
ROS
anti-cancer therapy
Opis:
Mitochondria play the central role in supplying cells with ATP and are also the major source of reactive oxygen species (ROS) - molecules of both regulatory and destructive nature. Dysfunction of mitochondrial metabolism and/or morphology have been frequently reported in human cancers. This dysfunction can be associated with mitochondrial DNA (mtDNA) damage, which may be changed into mutations in mtDNA coding sequences, or the displacement-loop region, changes in the mtDNA copy number or mtDNA microsatellite instability. All these features are frequently associated with human cancers. Mutations in mtDNA can disturb the functioning of the ROS-producing organelle and further affect the entire cell which may contribute to genomic instability typical for cancer cells. Although the association between some mtDNA mutations and cancer is well established, the causative relationship between these two features is largely unknown. A hint suggesting the driving role of mtDNA mutations in carcinogenesis comes from the observation of tumor promotion after mtDNA depletion. Mitochondria with damaged DNA may alter signaling of the mitochondrial apoptosis pathway promoting cancer cell survival and conferring resistance to anticancer drugs. This resistance may be underlined by mtDNA copy number depletion. Therefore, mitochondria are considered a promising target in anticancer therapy and several mitochondria-targeting drugs are in preclinical and clinical trials. Some other aspects of mitochondrial structure and functions, including morphology and redox potential, can also be associated with cancer transformation and constitute new anticancer targets. Recently, several studies have disclosed new mechanisms underlying the association between mitochondria and cancer, including the protection of mtDNA by telomerase, suggesting new approaches in mitochondria-oriented anti-cancer therapy.
Źródło:
Acta Biochimica Polonica; 2014, 61, 4; 671-678
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Role of anti-apoptotic pathways activated by BCR/ABL in the resistance of chronic myeloid leukemia cells to tyrosine kinase inhibitors
Autorzy:
Danisz, Katarzyna
Blasiak, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/1039432.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
BCR/ABL
chronic myeloid leukemia
apoptotic signaling
tyrosine kinase inhibitor
imatinib
drug resistance
Opis:
Chronic myeloid leukemia (CML) is a hematological stem cell disorder characterized by the excessive proliferation of the myeloid lineage. In its initial chronic phase, the myeloid progenitor cells expand and demonstrate apparently normal differentiation. The disease may then transform into the accelerated phase, usually associated with resistance to therapy, and finally, into acute leukemic progression phase - blast crisis. Abnormal myeloid cells produce progenitors, which have lost their ability to differentiate, but retain the capacity to proliferate. The molecular hallmark of CML is the Philadelphia chromosome, resulting from reciprocal chromosome translocation, t(9;22)(q34;q11), and containing the BCR/ABL fusion gene, producing the BCR/ABL protein with a constitutive tyrosine kinase activity. BCR/ABL-positive cells have faster growth and proliferation over their normal counterparts and are resistant to apoptosis. Introduction of imatinib (IM), a tyrosine kinase inhibitor, revolutionized the therapy of CML, changing it from a fatal disease into a chronic disorder. However, some patients show a primary resistance to IM, others acquire such resistance in the course of therapy. Therefore, a small number of leukemic stem cells retains self-renewal capacity under IM treatment. Because BCR/ABL is involved in many signaling pathways, some of them may be essential for resistance to IM-induced apoptosis. The PI3K/AKT, Ras and JAK/STAT signaling pathways are involved in resistance to apoptosis and can be activated by BCR/ABL. Therefore, they can be candidates for BCR/ABL-dependent pro-survival pathway(s), allowing a fraction of CML cells to withstand treatment with tyrosine kinase inhibitors.
Źródło:
Acta Biochimica Polonica; 2013, 60, 4; 503-514
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The role of microRNA in metastatic colorectal cancer and its significance in cancer prognosis and treatment
Autorzy:
Tokarz, Paulina
Blasiak, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/1039629.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
prognosis
colorectal cancer
metastasis
prediction
therapy
miRNA
Opis:
microRNAs (miRNAs) are small, non-coding RNA molecules that regulate gene expression by targeting specific mRNAs. microRNAs play a role in several physiological processes in the cell, including migration, proliferation, differentiation and apoptosis. Apart from their role in regular metabolism, abnormal profiles of miRNA expression accompany cancer transformation, including colorectal cancer (CRC) metastasis. microRNAs may play a role in each phase of CRC metastasis including angiogenesis, invasion, intravasation, circulation, extravasation and metastatic colonization. microRNA levels may serve as a predictive CRC marker, which was confirmed by the serum level of miR-29a targeting KLF4, a marker of cell stemness, and the plasma level of miR-221 down-regulating c-Kit, Stat5A and ETS1, which are signal transducers and transcription factor, respectively. In turn, the level of miR-143 in CRC cells decreasing the amount of MACC1 (metastasis-associated in colon cancer-1) and oncogenic KRAS protein, may be utilized as a prognostic marker. Also, single nucleotide polymorphisms of genes encoding miRNAs, including miR-423 and miR-608, which correlate with tumor recurrence, may be useful as diagnostic, prognostic and predictive indicators in CRC metastasis. Pre-miR-34a and pre-miR-199a decreased the level of Axl, a tyrosine-protein kinase receptor, so they can be considered as drugs in antimetastatic therapy. On the other hand, miR-222 targeting ADAM-17, a disintegrin and metalloproteinase, and miR-328 interacting with ABCG2, an ABC transporter, may overcome drug resistance of cancer cells. microRNAs may be considered in wide-range application to facilitate CRC metastasis diagnosis, prognosis, prediction and therapy, however, further clinical, epidemiological and in vitro studies should be conducted to verify their utility.
Źródło:
Acta Biochimica Polonica; 2012, 59, 4; 467-474
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Antigen levels of urokinase-type plasminogen activator receptor and its gene polymorphism related to microvessel density in colorectal cancer
Autorzy:
Przybylowska, Karolina
Szemraj, Janusz
Kulig, Andrzej
Dziki, Adam
Ulanska, Joanna
Blasiak, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/1040754.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
plasminogen activation system
urokinase type plasminogen activator receptor (uPAR)
gene polymorphism
colorectal cancer
cancer progression
angiogenesis
microvessel density
Opis:
We determined the distribution of genotypes and frequencies of alleles of the (CA)n repeat polymorphism in intron 3 of the urokinase plasminogen activator receptor (uPAR) gene, uPAR antigen levels and microvessel density (MVD) in tumour and distant mucosa samples from 52 patients with colorectal cancer. The uPAR level was higher for patients with high MVD comparing to patients with lower MVD which may suggest that uPAR can be correlated with progression of colorectal cancer. The significant relationship between the high MVD and uPAR antigen level appeared to be independent of the (CA)n repeat polymorphism because no differences in the level of uPAR antigen between carriers of alleles were found. The received results, indicate that uPAR might be considered as a target in colorectal cancer patients' therapy.
Źródło:
Acta Biochimica Polonica; 2008, 55, 2; 357-363
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the G/C polymorphism in the 5-untranslated region of the RAD51 gene in breast cancer.
Autorzy:
Blasiak, Janusz
Przybyłowska, Karolina
Czechowska, Agnieszka
Zadrożny, Marek
Pertyński, Tomasz
Rykała, Jan
Kołacińska, Agnieszka
Morawiec, Zbigniew
Drzewoski, Józef
Powiązania:
https://bibliotekanauki.pl/articles/1043672.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
genetic polymorphism
RAD51 gene
RFLP-PCR
breast cancer
Opis:
The breast cancer suppressor proteins BRCA1 and BRCA2 interact with RAD51, a protein essential for maintaining genomic stability by playing a central role in homology-dependent recombinational repair of the DNA double-strand breaks. Therefore, genetic variability in the RAD51 gene may contribute to the appearance and/or progression of breast cancer. A single nucleotide polymorphism in the 5'- untranslated region of RAD51 (a G to C substitution at position 135, the G/C polymorphism) is reported to modulate breast cancer risk. We investigated the distribution of genotypes and frequency of alleles of the G/C polymorphism in breast cancer. Tumor tissues were obtained from postmenopausal women with node-negative and node-positive breast carcinoma with uniform tumor size. Blood samples from age matched healthy women served as control. The G/C polymorphism was determined by PCR-based MvaI restriction fragment length polymorphism. The distribution of the genotypes of the G/C polymorphism did not differ significantly (P >0.05) from those predicted by the Hardy-Weinberg distribution. There were no differences in the genotype distribution and allele frequencies between node-positive and node-negative patients. There were no significant differences between distributions of the genotypes in subgroups assigned to histological grades according to Scarf-Bloom-Richardson criteria and the distribution predicted by Hardy-Weinberg equilibrium (P >0.05). Our study implies that the G/C polymorphism of the RAD51 gene may not be directly involved in the development and/or progression of breast cancer and so it may not be useful as an independent marker in this disease.
Źródło:
Acta Biochimica Polonica; 2003, 50, 1; 249-253
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Free radical scavengers can modulate the DNA-damaging action of alloxan.
Autorzy:
Blasiak, Janusz
Sikora, Agnieszka
Czechowska, Agnieszka
Drzewoski, Józef
Powiązania:
https://bibliotekanauki.pl/articles/1043667.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
vitamin C
spin trapping
free radicals
alloxan
vitamin E
DNA damage
ebselen
comet assay
DNA repair
diabetes mellitus
Opis:
Alloxan can generate diabetes in experimental animals and its action can be associated with the production of free radicals. It is therefore important to check how different substances often referred to as free radical scavengers may interact with alloxan, especially that some of these substance may show both pro- and antioxidant activities. Using the alkaline comet assay we showed that alloxan at concentrations 0.01-50 μM induced DNA damage in normal human lymphocytes in a dose-dependent manner. Treated cells were able to recover within a 120-min incubation. Vitamins C and E at 10 and 50 μM diminished the extent of DNA damage induced by 50 μM alloxan. Pre-treatment of the lymphocytes with a nitrone spin trap, α-(4-pyridil-1-oxide)- N-t-butylnitrone (POBN) or ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one), which mimics glutathione peroxides, reduced the alloxan-evoked DNA damage. The cells exposed to alloxan and treated with formamidopyrimidine-DNA glycosylase (Fpg) and 3-methyladenine-DNA glycosylase II (AlkA), enzymes recognizing oxidized and alkylated bases, respectively, displayed greater extent of DNA damage than those not treated with these enzymes. The results confirmed that free radicals are involved in the formation of DNA lesions induced by alloxan. The results also suggest that alloxan can generate oxidized DNA bases with a preference for purines and contribute to their alkylation.
Źródło:
Acta Biochimica Polonica; 2003, 50, 1; 205-210
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hyperthermia can differentially modulate the repair of doxorubicin-damaged DNA in normal and cancer cells*.
Autorzy:
Blasiak, Janusz
Widera, Kinga
Pertyński, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/1043663.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
hyperthermia
drug resistance
K562 cells
DNA repair
Opis:
Hyperthermia can modulate the action of many anticancer drugs, and DNA repair processes are temperature-dependent, but the character of this dependence in cancer and normal cells is largely unknown. This subject seems to be worth studying, because hyperthermia can assist cancer therapy. A 1-h incubation at 37°C of normal human peripheral blood lymphocytes and human myelogenous leukemia cell line K562 with 0.5 μM doxorubicin gave significant level of DNA damage as assessed by the alkaline comet assay. The cells were then incubated in doxorubicin-free repair medium at 37°C or 41°C. The lymphocytes incubated at 37°C needed about 60 min to remove completely the damage to their DNA, whereas at 41°C the time required for complete repair was shortened to 30 min. There was also a difference between the repair kinetics at 37°C and 41°C in cancer cells. Moreover, the kinetics were different in doxorubicin-sensitive and resistant cells. Therefore, hyperthermia may significantly affect the kinetics of DNA repair in drug-treated cells, but the magnitude of the effect may be different in normal and cancer cells. These features may be exploited in cancer chemotherapy to increase the effectiveness of the treatment and reduce unwanted effects of anticancer drugs in normal cells and fight DNA repair-based drug resistance of cancer cells.
Źródło:
Acta Biochimica Polonica; 2003, 50, 1; 191-195
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-homologous DNA end joining.
Autorzy:
Pastwa, Elżbieta
Błasiak, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/1043360.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
Ku proteins
DNA-PK
homologous recombination
non-homologous end joining
DSB; DNA repair
DNA ligase IV
DNA double-strand breaks
NHEJ
Opis:
DNA double-strand breaks (DSBs) are a serious threat for the cell and when not repaired or misrepaired can result in mutations or chromosome rearrangements and eventually in cell death. Therefore, cells have evolved a number of pathways to deal with DSB including homologous recombination (HR), single-strand annealing (SSA) and non-homologous end joining (NHEJ). In mammals DSBs are primarily repaired by NHEJ and HR, while HR repair dominates in yeast, but this depends also on the phase of the cell cycle. NHEJ functions in all kinds of cells, from bacteria to man, and depends on the structure of DSB termini. In this process two DNA ends are joined directly, usually with no sequence homology, although in the case of same polarity of the single stranded overhangs in DSBs, regions of microhomology are utilized. The usage of microhomology is common in DNA end-joining of physiological DSBs, such as at the coding ends in V(D)J (variable(diversity) joining) recombination. The main components of the NHEJ system in eukaryotes are the catalytic subunit of DNA protein kinase (DNA-PKcs), which is recruited by DNA Ku protein, a heterodimer of Ku70 and Ku80, as well as XRCC4 protein and DNA ligase IV. A complex of Rad50/Mre11/Xrs2, a family of Sir proteins and probably other yet unidentified proteins can be also involved in this process. NHEJ and HR may play overlapping roles in the repair of DSBs produced in the S phase of the cell cycle or at replication forks. Aside from DNA repair, NHEJ may play a role in many different processes, including the maintenance of telomeres and integration of HIV-1 genome into a host genome, as well as the insertion of pseudogenes and repetitive sequences into the genome of mammalian cells. Inhibition of NHEJ can be exploited in cancer therapy in radio-sensitizing cancer cells. Identification of all key players and fundamental mechanisms underlying NHEJ still requires further research.
Źródło:
Acta Biochimica Polonica; 2003, 50, 4; 891-908
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comparison of the in vitro genotoxicity of anticancer drugs idarubicin and mitoxantrone.
Autorzy:
Błasiak, Janusz
Gloc, Ewa
Warszawski, Mariusz
Powiązania:
https://bibliotekanauki.pl/articles/1043821.pdf
Data publikacji:
2002
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
mitoxantrone
oxidative DNA damage
DNA damage
idarubicin
comet assay
DNA methylation
DNA repair
Opis:
Idarubicin is an anthracycline antibiotic used in cancer therapy. Mitoxantrone is an anthracycline analog with presumed better antineoplastic activity and lesser toxicity. Using the alkaline comet assay we showed that the drugs at 0.01-10 μM induced DNA damage in normal human lymphocytes. The effect induced by idarubicin was more pronounced than by mitoxantrone (P < 0.001). The cells treated with mitoxantrone at 1 μM were able to repair damage to their DNA within a 30-min incubation, whereas the lymphocytes exposed to idarubicin needed 180 min. Since anthracyclines are known to produce free radicals, we checked whether reactive oxygen species might be involved in the observed DNA damage. Catalase, an enzyme inactivating hydrogen peroxide, decreased the extent of DNA damage induced by idarubicin, but did not affect the extent evoked by mitoxantrone. Lymphocytes exposed to the drugs and treated with endonuclease III or formamidopyrimidine-DNA glycosylase (Fpg), enzymes recognizing and nicking oxidized bases, displayed a higher level of DNA damage than the untreated ones. 3-Methyladenine-DNA glycosylase II (AlkA), an enzyme recognizing and nicking mainly methylated bases in DNA, increased the extent of DNA damage caused by idarubicin, but not that induced by mitoxantrone. Our results indicate that the induction of secondary malignancies should be taken into account as side effects of the two drugs. Direct strand breaks, oxidation and methylation of the DNA bases can underlie the DNA-damaging effect of idarubicin, whereas mitoxantrone can induce strand breaks and modification of the bases, including oxidation. The observed in normal lymphocytes much lesser genotoxicity of mitoxantrone compared to idarubicin should be taken into account in planning chemotherapeutic strategies.
Źródło:
Acta Biochimica Polonica; 2002, 49, 1; 145-155
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recognition and repair of DNA-cisplatin adducts.
Autorzy:
Woźniak, Katarzyna
Błasiak, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/1043720.pdf
Data publikacji:
2002
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
DNA-protein crosslinks
cisplatin
DNA adducts
DNA damage
DNA repair
cis-diamminedichloroplatinum
Opis:
Anticancer activity of cisplatin (cis-diamminedichloroplatinum) is believed to result from its interaction with DNA. The drug reacts with nucleophilic sites in DNA forming monoadducts as well as intra- and interstrand crosslinks. DNA-cisplatin adducts are specifically recognized by several proteins. They can be divided into two classes. One constitutes proteins which recognize DNA damage as an initial step of the nucleotide excision and mismatch repair pathways. The other class contains proteins stabilizing cellular DNA-protein and protein-protein complexes, including non-histone proteins from the HMG (high-mobility-group) family. They specifically recognize 1,2-interstrand d(GpG) and d(ApG) crosslinks of DNA-cisplatin adducts and inhibit their repair. Many HMG-domain proteins can function as transcription factors, e.g. UBF, an RNA polymerase I transcription factor, the mammalian testis-determining factor SRY and the human mitochondrial transcription factor mtTFA. Moreover, it seems that some proteins, which probably recognize DNA-cisplatin adducts non-specifically, e.g. actin and other nuclear matrix proteins, can disturb the structural and functional organization of the nucleus and whole cell. The formation of complexes between DNA and proteins in the presence of cisplatin and the changes in the cell architecture may account for the drug cytotoxicity.
Źródło:
Acta Biochimica Polonica; 2002, 49, 3; 583-596
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies