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1.
Nat Chem Biol ; 20(6): 689-698, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38167920

RESUMO

Cleavage of bacteriophage DNA by the Type III restriction-modification enzymes requires long-range interaction between DNA sites. This is facilitated by one-dimensional diffusion ('DNA sliding') initiated by ATP hydrolysis catalyzed by a superfamily 2 helicase-like ATPase. Here we combined ultrafast twist measurements based on plasmonic DNA origami nano-rotors with stopped-flow fluorescence and gel-based assays to examine the role(s) of ATP hydrolysis. Our data show that the helicase-like domain has multiple roles. First, this domain stabilizes initial DNA interactions alongside the methyltransferase subunits. Second, it causes environmental changes in the flipped adenine base following hydrolysis of the first ATP. Finally, it remodels nucleoprotein interactions via constrained translocation of a ∼ 5 to 22-bp double stranded DNA loop. Initiation of DNA sliding requires 8-15 bp of DNA downstream of the motor, corresponding to the site of nuclease domain binding. Our data unify previous contradictory communication models for Type III enzymes.


Assuntos
Trifosfato de Adenosina , Difusão , Trifosfato de Adenosina/metabolismo , Trifosfato de Adenosina/química , Hidrólise , DNA/metabolismo , DNA/química , DNA Viral/metabolismo , DNA Viral/química , DNA Viral/genética , Desoxirribonucleases de Sítio Específico do Tipo III/metabolismo , Desoxirribonucleases de Sítio Específico do Tipo III/química
2.
J Theor Biol ; 575: 111626, 2023 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-37758120

RESUMO

Predator-prey relationships are fundamental components of ecosystem functioning, within which the spatial consequences of prey social organization can alter predation rates. Group-living (GL) species are known to exploit inadvertent social information (ISI) that facilitates population persistence under predation risk. Still, the extent to which non-grouping (NG) prey can benefit from similar processes is unknown. Here we built an individual-based model to explore and compare the population-level consequences of ISI use in GL and NG prey. We differentiated between GL and NG prey only by the presence or absence of social attraction toward conspecifics that drives individual movement patterns. We found that the extent of the benefits of socially acquired predator information in NG highly depends on the prey's ability to detect nearby predators, prey density and the occurrence of false alarms. Conversely, even moderate probabilities of ISI use and predator detection can lead to maximal population-level benefits in GL prey. This theoretical work provides additional insights into the conditions under which ISI use can facilitate population persistence irrespective of prey social organisation.


Assuntos
Ecossistema , Comportamento Predatório , Animais , Dinâmica Populacional
3.
Int J Mol Sci ; 24(13)2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37445923

RESUMO

Dystonia is a rare movement disorder which is characterized by sustained or intermittent muscle contractions causing abnormal and often repetitive movements, postures, or both. The two most common forms of adult-onset focal dystonia are cervical dystonia (CD) and benign essential blepharospasm (BSP). A total of 121 patients (CD, 74; BSP, 47) were included in the study. The average age of the patients was 64 years. For the next-generation sequencing (NGS) approach, 30 genes were selected on the basis of a thorough search of the scientific literature. Assessment of 30 CD- and BSP-associated genes from 121 patients revealed a total of 209 different heterozygous variants in 24 genes. Established clinical and genetic validity was determined for nine heterozygous variations (three likely pathogenic and six variants of uncertain significance). Detailed genetic examination is an important part of the work-up for focal dystonia forms. To our knowledge, our investigation is the first such study to be carried out in the Middle-European region.


Assuntos
Blefarospasmo , Distúrbios Distônicos , Torcicolo , Adulto , Humanos , Pessoa de Meia-Idade , Hungria , Distúrbios Distônicos/diagnóstico , Distúrbios Distônicos/genética , Blefarospasmo/diagnóstico , Torcicolo/diagnóstico , Torcicolo/genética , Testes Genéticos
4.
BMC Cancer ; 22(1): 605, 2022 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-35655145

RESUMO

BACKGROUND: Hypomethylation of long interspersed nuclear element 1 (LINE-1) is characteristic of various cancer types, including colorectal cancer (CRC). Malfunction of several factors or alteration of methyl-donor molecules' (folic acid and S-adenosylmethionine) availability can contribute to DNA methylation changes. Detection of epigenetic alterations in liquid biopsies can assist in the early recognition of CRC. Following the investigations of a Hungarian colon tissue sample set, our goal was to examine the LINE-1 methylation of blood samples along the colorectal adenoma-carcinoma sequence and in inflammatory bowel disease. Moreover, we aimed to explore the possible underlying mechanisms of global DNA hypomethylation formation on a multi-level aspect. METHODS: LINE-1 methylation of colon tissue (n = 183) and plasma (n = 48) samples of healthy controls and patients with colorectal tumours were examined with bisulfite pyrosequencing. To investigate mRNA expression, microarray analysis results were reanalysed in silico (n = 60). Immunohistochemistry staining was used to validate DNA methyltransferases (DNMTs) and folate receptor beta (FOLR2) expression along with the determination of methyl-donor molecules' in situ level (n = 40). RESULTS: Significantly decreased LINE-1 methylation level was observed in line with cancer progression both in tissue (adenoma: 72.7 ± 4.8%, and CRC: 69.7 ± 7.6% vs. normal: 77.5 ± 1.7%, p ≤ 0.01) and liquid biopsies (adenoma: 80.0 ± 1.7%, and CRC: 79.8 ± 1.3% vs. normal: 82.0 ± 2.0%, p ≤ 0.01). However, no significant changes were recognized in inflammatory bowel disease cases. According to in silico analysis of microarray data, altered mRNA levels of several DNA methylation-related enzymes were detected in tumours vs. healthy biopsies, namely one-carbon metabolism-related genes-which met our analysing criteria-showed upregulation, while FOLR2 was downregulated. Using immunohistochemistry, DNMTs, and FOLR2 expression were confirmed. Moreover, significantly diminished folic acid and S-adenosylmethionine levels were observed in parallel with decreasing 5-methylcytosine staining in tumours compared to normal adjacent to tumour tissues (p ≤ 0.05). CONCLUSION: Our results suggest that LINE-1 hypomethylation may have a distinguishing value in precancerous stages compared to healthy samples in liquid biopsies. Furthermore, the reduction of global DNA methylation level could be linked to reduced methyl-donor availability with the contribution of decreased FOLR2 expression.


Assuntos
Adenoma , Neoplasias Colorretais , Receptor 2 de Folato , Doenças Inflamatórias Intestinais , Adenoma/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , DNA/metabolismo , Metilação de DNA , Receptor 2 de Folato/genética , Receptor 2 de Folato/metabolismo , Ácido Fólico , Humanos , Biópsia Líquida , RNA Mensageiro/metabolismo , S-Adenosilmetionina/metabolismo
5.
Int J Mol Sci ; 23(19)2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36232908

RESUMO

Long interspersed nuclear element 1 (LINE-1) bisulfite pyrosequencing is a widely used technique for genome-wide methylation analyses. We aimed to investigate the effects of experimental and biological factors on its results to improve the comparability. LINE-1 bisulfite pyrosequencing was performed on colorectal tissue (n = 222), buffy coat (n = 39), and plasma samples (n = 9) of healthy individuals and patients with colorectal tumors. Significantly altered methylation was observed between investigated LINE-1 CpG positions of non-tumorous tissues (p ≤ 0.01). Formalin-fixed, paraffin-embedded biopsies (73.0 ± 5.3%) resulted in lower methylation than fresh frozen samples (76.1 ± 2.8%) (p ≤ 0.01). DNA specimens after long-term storage showed higher methylation levels (+3.2%, p ≤ 0.01). In blood collection tubes with preservatives, cfDNA and buffy coat methylation significantly changed compared to K3EDTA tubes (p ≤ 0.05). Lower methylation was detected in older (>40 years, 76.8 ± 1.7%) vs. younger (78.1 ± 1.0%) female patients (p ≤ 0.05), and also in adenomatous tissues with MTHFR 677CT, or 1298AC mutations vs. wild-type (p ≤ 0.05) comparisons. Based on our findings, it is highly recommended to consider the application of standard DNA samples in the case of a possible clinical screening approach, as well as in experimental research studies.


Assuntos
Ácidos Nucleicos Livres , Neoplasias Colorretais , Idoso , Fatores Biológicos , Biópsia , Ácidos Nucleicos Livres/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , DNA/genética , Metilação de DNA , Feminino , Formaldeído , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Biópsia Líquida , Elementos Nucleotídeos Longos e Dispersos/genética , Masculino , Sulfitos
6.
Int J Mol Sci ; 23(7)2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35409133

RESUMO

Monitoring the therapeutic response of colorectal cancer (CRC) patients is crucial to determine treatment strategies; therefore, we constructed a liquid biopsy-based approach for tracking tumor dynamics in non-metastatic (nmCRC) and metastatic (mCRC) patients (n = 55). Serial blood collections were performed during chemotherapy for measuring the amount and the global methylation pattern of cell-free DNA (cfDNA), the promoter methylation of SFRP2 and SDC2 genes, and the plasma homocysteine level. The average cfDNA amount was higher (p < 0.05) in nmCRC patients with recurrent cancer (30.4 ± 17.6 ng) and mCRC patients with progressive disease (PD) (44.3 ± 34.5 ng) compared to individuals with remission (13.2 ± 10.0 ng) or stable disease (12.5 ± 3.4 ng). More than 10% elevation of cfDNA from first to last sample collection was detected in all recurrent cases and 92% of PD patients, while a decrease was observed in most patients with remission. Global methylation level changes indicated a decline (75.5 ± 3.4% vs. 68.2 ± 8.4%), while the promoter methylation of SFRP2 and SDC2 and homocysteine level (10.9 ± 3.4 µmol/L vs. 13.7 ± 4.3 µmol/L) presented an increase in PD patients. In contrast, we found exact opposite changes in remission cases. Our study offers a more precise blood-based approach to monitor the treatment response to different chemotherapies than the currently used markers.


Assuntos
Ácidos Nucleicos Livres , Neoplasias Colorretais , Biomarcadores Tumorais/genética , Ácidos Nucleicos Livres/genética , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/cirurgia , Metilação de DNA , Homocisteína , Humanos , Biópsia Líquida , Recidiva Local de Neoplasia/genética
7.
Yeast ; 38(3): 206-221, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33244789

RESUMO

During the mitotic cycle, the rod-shaped fission yeast cells grow only at their tips. The newly born cells grow first unipolarly at their old end, but later in the cycle, the 'new end take-off' event occurs, resulting in bipolar growth. Photographs were taken of several steady-state and induction synchronous cultures of different cell cycle mutants of fission yeast, generally larger than wild type. Length measurements of many individual cells were performed from birth to division. For all the measured growth patterns, three different functions (linear, bilinear and exponential) were fitted, and the most adequate one was chosen by using specific statistical criteria, considering the altering parameter numbers. Although the growth patterns were heterogeneous in all the cultures studied, we could find some tendencies. In cultures with sufficiently wide size distribution, cells large enough at birth tend to grow linearly, whereas the other cells generally tend to grow bilinearly. We have found that among bilinearly growing cells, the larger they are at birth, the rate change point during their bilinear pattern occurs earlier in the cycle. This shifting near to the beginning of the cycle might finally cause a linear pattern, if the cells are even larger. In all of the steady-state cultures studied, a size control mechanism operates to maintain homeostasis. By contrast, strongly oversized cells of induction synchronous cultures lack any sizer, and their cycle rather behaves like an adder. We could determine the critical cell size for both the G1 and G2 size controls, where these mechanisms become cryptic. TAKE AWAY: Most individual fission yeast cells in steady-state cultures grow bilinearly. In strongly oversized fission yeast cells, linear growth dominates over bilinear. Above birth length thresholds, both the G1 and G2 size controls become cryptic.


Assuntos
Tamanho Celular , Mitose , Schizosaccharomyces/citologia , Schizosaccharomyces/crescimento & desenvolvimento , Homeostase , Mutação , Schizosaccharomyces/genética
8.
Arch Phys Med Rehabil ; 102(1): 9-18, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32861668

RESUMO

OBJECTIVES: To determine the effects of exergaming on quality of life (QoL), motor, and clinical symptoms in subacute stroke patients. DESIGN: A pseudorandomized controlled trial, using a before-after test design. SETTING: University hospital. PARTICIPANTS: Subacute, ischemic stroke outpatients (N=3857), 680 of whom were randomized and 641 completed the study. INTERVENTIONS: We determined the effects of 5 times a week twice daily (EX2; 50 sessions; n=286) and once daily (EX1; 25 sessions; n=272) exergaming and low-intensity standard care (control [CON]; 25 sessions; n=83) on clinical, mobility, blood pressure (BP), and QoL outcomes. MAIN OUTCOME MEASURES: The primary outcome was Modified Rankin Scale. Secondary outcomes were activities of daily living, 5 aspects of health-related QoL, Beck Depression Inventory, 6-minute walk test (6MWT), Berg Balance Scale (BBS), and static balance (center of pressure). RESULTS: During exercise, the peak heart rate was 134, 134, and 126 beats per minute in the EX2, EX1, and CON groups, respectively. mRS improved similarly in the EX2 (-1.8; effect size, d=-4.0) and EX1 (-1.4; d=-2.6) groups, but more than in the CON group (-0.7; d=-0.6). QoL, Barthel Index, BBS, 6MWT, and standing posturography improved more in the EX2 group and the same in the EX1 and CON groups. Systolic and diastolic resting BP decreased more in the EX2 and EX1 groups than in the CON group. The intervention effects did not differ between men (n=349) and women (n=292). CONCLUSIONS: Twice daily compared with once daily high-intensity exergaming or once daily lower intensity standard care produced superior effects on clinical and motor symptoms, BP, and QoL in male and female subacute ischemic stroke participants.


Assuntos
Terapia por Exercício/métodos , AVC Isquêmico/reabilitação , Reabilitação do Acidente Vascular Cerebral/métodos , Jogos de Vídeo , Atividades Cotidianas , Idoso , Pressão Sanguínea , Comorbidade , Feminino , Marcha/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Limitação da Mobilidade , Equilíbrio Postural/fisiologia , Qualidade de Vida , Método Simples-Cego
9.
Int J Mol Sci ; 21(7)2020 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-32283839

RESUMO

Dietary trans fatty acids (TFAs) have been implicated in serious health risks, yet little is known about their cellular effects and metabolism. We aim to undertake an in vitro comparison of two representative TFAs (elaidate and vaccenate) to the best-characterized endogenous cis-unsaturated FA (oleate). The present study addresses the possible protective action of TFAs on palmitate-treated RINm5F insulinoma cells with special regards to apoptosis, endoplasmic reticulum stress and the underlying ceramide and diglyceride (DG) accumulation. Both TFAs significantly improved cell viability and reduced apoptosis in palmitate-treated cells. They mildly attenuated palmitate-induced XBP-1 mRNA cleavage and phosphorylation of eukaryotic initiation factor 2α (eIF2α) and stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK), but they were markedly less potent than oleate. Accordingly, all the three unsaturated FAs markedly reduced cellular palmitate incorporation and prevented harmful ceramide and DG accumulation. However, more elaidate or vaccenate than oleate was inserted into ceramides and DGs. Our results revealed a protective effect of TFAs in short-term palmitate toxicity, yet they also provide important in vitro evidence and even a potential mechanism for unfavorable long-term health effects of TFAs compared to oleate.


Assuntos
Ceramidas/metabolismo , Diglicerídeos/metabolismo , Ácidos Graxos Monoinsaturados/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Palmitatos/efeitos adversos , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Ácidos Graxos Monoinsaturados/química , Ratos
10.
BMC Cancer ; 19(1): 1059, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31694571

RESUMO

BACKGROUND: Long non-coding RNAs (lncRNAs) play a fundamental role in colorectal cancer (CRC) development, however, lncRNA expression profiles in CRC and its precancerous stages remain to be explored. We aimed to study whole genomic lncRNA expression patterns in colorectal adenoma-carcinoma transition and to analyze the underlying functional interactions of aberrantly expressed lncRNAs. METHODS: LncRNA expression levels of colonic biopsy samples (20 CRCs, 20 adenomas (Ad), 20 healthy controls (N)) were analyzed with Human Transcriptome Array (HTA) 2.0. Expression of a subset of candidates was verified by qRT-PCR and in situ hybridization (ISH) analyses. Furthermore, in silico validation was performed on an independent HTA 2.0, on HGU133Plus 2.0 array data and on the TCGA COAD dataset. MiRNA targets of lncRNAs were predicted with miRCODE and lncBase v2 algorithms and miRNA expression was analyzed on miRNA3.0 Array data. MiRNA-mRNA target prediction was performed using miRWALK and c-Met protein levels were analyzed by immunohistochemistry. Comprehensive lncRNA-mRNA-miRNA co-expression pattern analysis was also performed. RESULTS: Based on our HTA results, a subset of literature-based CRC-associated lncRNAs showed remarkable expression changes already in precancerous colonic lesions. In both Ad vs. normal and CRC vs. normal comparisons 16 lncRNAs, including downregulated LINC02023, MEG8, AC092834.1, and upregulated CCAT1, CASC19 were identified showing differential expression during early carcinogenesis that persisted until CRC formation (FDR-adjusted p < 0.05). The intersection of CRC vs. N and CRC vs. Ad comparisons defines lncRNAs characteristic of malignancy in colonic tumors, where significant downregulation of LINC01752 and overexpression of UCA1 and PCAT1 were found. Two candidates with the greatest increase in expression in the adenoma-carcinoma transition were further confirmed by qRT-PCR (UCA1, CCAT1) and by ISH (UCA1). In line with aberrant expression of certain lncRNAs in tumors, the expression of miRNA and mRNA targets showed systematic alterations. For example, UCA1 upregulation in CRC samples occurred in parallel with hsa-miR-1 downregulation, accompanied by c-Met target mRNA overexpression (p < 0.05). CONCLUSION: The defined lncRNA sets may have a regulatory role in the colorectal adenoma-carcinoma transition. A subset of CRC-associated lncRNAs showed significantly differential expression in precancerous samples, raising the possibility of developing adenoma-specific markers for early detection of colonic lesions.


Assuntos
Adenoma/genética , Carcinoma/genética , Neoplasias Colorretais/genética , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , RNA Longo não Codificante/genética , Adenoma/patologia , Adulto , Idoso , Carcinoma/patologia , Neoplasias Colorretais/patologia , Ontologia Genética , Redes Reguladoras de Genes , Humanos , Pessoa de Meia-Idade , Modelos Genéticos , Adulto Jovem
11.
BMC Cancer ; 18(1): 695, 2018 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-29945573

RESUMO

BACKGROUND: DNA mutations occur randomly and sporadically in growth-related genes, mostly on cytosines. Demethylation of cytosines may lead to genetic instability through spontaneous deamination. Aims were whole genome methylation and targeted mutation analysis of colorectal cancer (CRC)-related genes and mRNA expression analysis of TP53 pathway genes. METHODS: Long interspersed nuclear element-1 (LINE-1) BS-PCR followed by pyrosequencing was performed for the estimation of global DNA metlyation levels along the colorectal normal-adenoma-carcinoma sequence. Methyl capture sequencing was done on 6 normal adjacent (NAT), 15 adenomatous (AD) and 9 CRC tissues. Overall quantitative methylation analysis, selection of top hyper/hypomethylated genes, methylation analysis on mutation regions and TP53 pathway gene promoters were performed. Mutations of 12 CRC-related genes (APC, BRAF, CTNNB1, EGFR, FBXW7, KRAS, NRAS, MSH6, PIK3CA, SMAD2, SMAD4, TP53) were evaluated. mRNA expression of TP53 pathway genes was also analyzed. RESULTS: According to the LINE-1 methylation results, overall hypomethylation was observed along the normal-adenoma-carcinoma sequence. Within top50 differential methylated regions (DMRs), in AD-N comparison TP73, NGFR, PDGFRA genes were hypermethylated, FMN1, SLC16A7 genes were hypomethylated. In CRC-N comparison DKK2, SDC2, SOX1 genes showed hypermethylation, while ERBB4, CREB5, CNTN1 genes were hypomethylated. In certain mutation hot spot regions significant DNA methylation alterations were detected. The TP53 gene body was addressed by hypermethylation in adenomas. APC, TP53 and KRAS mutations were found in 30, 15, 21% of adenomas, and in 29, 53, 29% of CRCs, respectively. mRNA expression changes were observed in several TP53 pathway genes showing promoter methylation alterations. CONCLUSIONS: DNA methylation with consecutive phenotypic effect can be observed in a high number of promoter and gene body regions through CRC development.


Assuntos
Neoplasias Colorretais/genética , Metilação de DNA , Éxons , Mutação , Regiões Promotoras Genéticas , Adenoma/genética , Ilhas de CpG , Humanos , Elementos Nucleotídeos Longos e Dispersos , Transdução de Sinais , Proteína Supressora de Tumor p53/fisiologia
12.
Orv Hetil ; 159(6): 223-233, 2018 Feb.
Artigo em Húngaro | MEDLINE | ID: mdl-29400102

RESUMO

INTRODUCTION: Cell-free DNA (cfDNA) was first detected in human plasma in the 1940s, but the knowledge on its regulation and rate of release is incomplete. CfDNA can originate from both normal and tumour cells. AIM: Our aims were to investigate the rate of cfDNA's release in SHO mice/HT-29 colorectal adenocarcinoma cell line xenograft model and to define the decay of methylated and non-methylated DNA fragments in C57BL/6 bloodstream. METHOD: SHO mice were xenografted with human HT-29 cells, than blood samples were collected over 2 months. CfDNA was isolated, then quantified by real-time PCR with highly specific genomic and mitochondrial human and mouse primer sets. This method permitted to define the ratio of human/mouse DNA. To assess the degradation rate of cfDNA, 3000 bp sized methylated and non-methylated DNA fragments were injected into healthy and C38 tumour-cell vaccinated C57BL/6 mice's bloodstream. The decay of amplicons was measured with 19 PCR assays. RESULTS: The amount of human DNA until the 2nd week was below the limit of detection. From the third week, a continuous growth was experienced, which reached 18.26% by the 8th week. Moreover, it was found that in healthy animals the non-methylated DNA disappears from the plasma after 6 hours, while the methylated fragment was detectable even after 24 hours. In animals with tumour, both amplicons were detectable after 24 hours. CONCLUSION: The examination of the role and mechanism of cfDNA shows an increasing level of interest. This work can contribute to a better understanding of the release and degradation of cfDNA. Orv Hetil. 2018; 159(6): 223-233.


Assuntos
Adenocarcinoma/sangue , Biomarcadores Tumorais/sangue , Ácidos Nucleicos Livres/sangue , Fragmentação do DNA , DNA de Neoplasias/sangue , Animais , Camundongos , Camundongos Endogâmicos C57BL
13.
Orv Hetil ; 159(1): 3-15, 2018 Jan.
Artigo em Húngaro | MEDLINE | ID: mdl-29291647

RESUMO

Besides the genetic research, increasing number of scientific studies focus on epigenetic phenomena - such as DNA methylation - regulating the expression of genes behind the phenotype, thus can be related to the pathomechanism of several diseases. In this review, we aim to summarize the current knowledge about the evolutionary appearance and functional diversity of DNA methylation as one of the epigenetic mechanisms and to demonstrate its role in aging and cancerous diseases. DNA methylation is also characteristic/also appear to prokaryotes, eukaryotes and viruses. In prokaryotes and viruses, it provides defence mechanisms against extragenous DNA. DNA methylation in prokaryotes plays a significant role in the regulation of transcription, the initiation of replication and in Dam-directed mismatch repair. In viruses, it participates not only in defence mechanisms, but in the assembly of capsids as well which is necessary for spreading. In eukaryotes, DNA methylation is involved in recombination, replication, X chromosome inactivation, transposon control, regulation of chromatin structure and transcription, and it also contributes to the imprinting phenomenon. Besides the above-mentioned aspects, DNA methylation also has an evolutionary role as it can change DNA mutation rate. Global hypomethylation appearing during aging and in cancerous diseases can lead to genetic instablility and spontaneous mutations through its role in the regulation of transposable elements. Local hypermethylated alterations such as hypermethylation of SFRP1, SFRP2, DKK1 and APC gene promoters can cause protein expression changes, thus contribute to development of cancer phenotype. DNA methylation alterations during aging in cancerous diseases support the importance of epigenetic research focusing on disease diagnostics and prognostics. Orv Hetil. 2018; 159(1): 3-15.


Assuntos
Envelhecimento/metabolismo , Biomarcadores Tumorais/metabolismo , Epigênese Genética/genética , Neoplasias/genética , Idoso , Idoso de 80 Anos ou mais , Metilação de DNA , Humanos , Neoplasias/metabolismo
14.
Amino Acids ; 48(1): 31-40, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26250429

RESUMO

Transglutaminase 2 (TG2) is a multifunctional protein with diverse catalytic activities and biological roles. Its best studied function is the Ca(2+)-dependent transamidase activity leading to formation of γ-glutamyl-ε-lysine isopeptide crosslinks between proteins and γ-glutamyl-amine derivatives. TG2 has a poorly studied isopeptidase activity cleaving these bonds. We have developed and characterised TG2 mutants which are significantly deficient in transamidase activity while have normal or increased isopeptidase activity (W332F) and vice versa (W278F). The W332F mutation led to significant changes of both the K m and the V max kinetic parameters of the isopeptidase reaction of TG2 while its calcium and GTP sensitivity was similar to the wild-type enzyme. The W278F mutation resulted in six times elevated amine incorporating transamidase activity demonstrating the regulatory significance of W278 and W332 in TG2 and that mutations can change opposed activities located at the same active site. The further application of our results in cellular systems may help to understand TG2-driven physiological and pathological processes better and lead to novel therapeutic approaches where an increased amount of crosslinked proteins correlates with the manifestation of degenerative disorders.


Assuntos
Aminas/metabolismo , Carbono-Nitrogênio Liases/química , Carbono-Nitrogênio Liases/metabolismo , Proteínas de Ligação ao GTP/química , Proteínas de Ligação ao GTP/metabolismo , Transglutaminases/química , Transglutaminases/metabolismo , Cálcio/metabolismo , Carbono-Nitrogênio Liases/genética , Domínio Catalítico , Proteínas de Ligação ao GTP/genética , Humanos , Cinética , Mutação de Sentido Incorreto , Proteína 2 Glutamina gama-Glutamiltransferase , Transglutaminases/genética
15.
Orv Hetil ; 157(22): 849-54, 2016 May 29.
Artigo em Húngaro | MEDLINE | ID: mdl-27211354

RESUMO

INTRODUCTION: Contact force sensing radiofrequency ablation and the new generation cryoballoon ablation are prevalent techniques for the treatment of paroxysmal atrial fibrillation. AIM: The authors aimed to compare the procedural and 1-year outcome of patients after radiofrequency and cryoballoon ablation. METHOD: 96 patients with paroxysmal atrial fibrillation (radiofrequency ablation: 58, cryoballoon: 38 patients; 65 men and 31 women aged 28-70 years) were enrolled. At postprocedural 1, 3, 6 and 12 months ECG, Holter monitoring and telephone interviews were performed. RESULTS: Procedure and fluorosocopy time were: radiofrequency ablation, 118.5 ± 15 min and 15.8 ± 6 min; cryoballoon, 73.5 ± 16 min (p<0.05) and 13.8 ± 4.,1 min (p = 0.09), respectively. One year later freedom from atrial fibrillation was achieved in 76.5% of patients who underwent radiofrequency ablation and in 81% of patients treated with cryoballoon. Temporary phrenic nerve palsy occurred in two patients and pericardial tamponade developed in one patient. CONCLUSIONS: In this single center study freedom from paroxysmal atrial fibrillation was similar in the two groups with significant shorter procedure time in the cryoballoon group.


Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter , Criocirurgia , Adulto , Idoso , Fibrilação Atrial/fisiopatologia , Ablação por Cateter/métodos , Criocirurgia/métodos , Eletrocardiografia , Eletrocardiografia Ambulatorial , Feminino , Fluoroscopia , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Doses de Radiação , Recidiva , Índice de Gravidade de Doença , Resultado do Tratamento
16.
BMC Cancer ; 15: 736, 2015 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-26482433

RESUMO

BACKGROUND: Colorectal cancer (CRC) development is accompanied by changes in expression for several genes; but the details of the underlying regulatory procesess remain unknown. Our aims were to assess the role of epigenetic processes in tumour formation and to identify characteristic DNA methylation and miRNA alterations in the colorectal adenoma-carcinoma sequence. METHODS: Whole genome expression profiling was performed on colonic biopsy samples (49 healthy normal, 49 colorectal adenoma (AD), 49 CRC); on laser capture microdissected (LCM) epithelial and stromal cells from 6 CRC-normal adjacent tissue (NAT) samples pairs, and on demethylated human CRC cell lines using HGU133 Plus 2.0 microarrays (Affymetrix). Methylation status of genes with gradually altering expression along the AD-CRC sequence was further analysed on 10-10 macrodissected and 5-5 LCM samples from healthy colon, from adenoma and from CRC biopsy samples using bisulfite-sequencing PCR (BS-PCR) followed by pyrosequencing. In silico miRNA prediction for the selected genes was performed with miRWALK algorithm, miRNA expression was analysed on 3 CRC-NAT sample pairs and 3 adenoma tissue samples using the Human Panel I + II (Exiqon). SFRP1 immunohistochemistry experiments were performed. RESULTS: A set of transcripts (18 genes including MAL, SFRP1, SULT1A1, PRIMA1, PTGDR) showed decreasing expression (p < 0.01) in the biopsy samples along the adenoma-carcinoma sequence. Three of those (COL1A2, SFRP2, SOCS3) showed hypermethylation and THBS2 showed hypomethylation both in AD and in CRC samples compared to NAT, while BCL2, PRIMA1 and PTGDR showed hypermethylation only in the CRC group. miR-21 was found to be significantly (p < 0.01) upregulated in adenoma and tumour samples compared to the healthy colonic tissue controls and could explain the altered expression of genes for which DNA methylation changes do not appear to play role (e.g. BCL2, MAL, PTGS2). Demethylation treatment could upregulate gene expression of genes that were found to be hypermethylated in human CRC tissue samples. Decreasing protein levels of SFRP1 was also observed along the adenoma-carcinoma sequence. CONCLUSION: Hypermethylation of the selected markers (MAL, PRIMA1, PTGDR and SFRP1) can result in reduced gene expression and may contribute to the formation of colorectal cancer.


Assuntos
Adenoma/genética , Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intercelular/genética , Proteínas de Membrana/genética , Proteínas Proteolipídicas Associadas a Linfócitos e Mielina/genética , Proteínas do Tecido Nervoso/genética , Receptores Imunológicos/genética , Receptores de Prostaglandina/genética , Adenoma/metabolismo , Adenoma/patologia , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Metilação de DNA , Humanos , Imuno-Histoquímica , Peptídeos e Proteínas de Sinalização Intercelular/biossíntese , Proteínas de Membrana/biossíntese , Proteínas Proteolipídicas Associadas a Linfócitos e Mielina/biossíntese , Proteínas do Tecido Nervoso/biossíntese , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas , RNA Mensageiro/genética , Receptores Imunológicos/biossíntese , Receptores de Prostaglandina/biossíntese
17.
Genes Chromosomes Cancer ; 52(9): 785-93, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23720363

RESUMO

Multiple myeloma (MM) is a genetically heterogeneous disease with diverse clinical outcomes. Interphase fluorescence in situ hybridization (i-FISH) is the most commonly used approach to detect recurrent cytogenetic abnormalities in this malignancy. We aimed to assess the performance of multiplex ligation-dependent probe amplification (MLPA) to reveal copy number abnormalities (CNAs) in MM. Diagnostic bone marrow samples from 81 patients were analyzed using 42 MLPA probes for the following regions: 1p32-31, 1p21, 1q21.3, 1q23.3, 5q31.3, 12p13.31, 13q14, 16q12, 16q23, and 17p13. All samples were also screened by i-FISH for the presence of hyperdiploidy, deletion/monosomy of chromosome 13, deletion of TP53, disruption of the immunoglobulin heavy-chain gene, t(4;14), t(11;14), t(14;16), t(8;14), gain of 5q and abnormalities of chromosome 1. A total of 245 alterations were detected in 79 cases (98%). Investigating the same aberrations, the two methods showed a congruency of higher than 90%. A low proportion of cells with the relevant abnormality, focal CNAs and unmatched probes were responsible for the discrepancies. MLPA revealed 95 CNAs not detected by i-FISH providing additional information in 53 cases (65%). Scrutiny of CNAs on chromosome 1, using more than 20 probes, revealed significant heterogeneity in size and location, and variable intra-chromosomal and intra-clonal rates of loss or gain. Our results suggest that MLPA is a reliable high-throughput technique to detect CNAs in MM. Since balanced aberrations are key to prognostic classification of this disease, MLPA and i-FISH should be applied as complementary techniques in diagnostic pathology.


Assuntos
Aberrações Cromossômicas , Análise Citogenética/métodos , Hibridização in Situ Fluorescente , Mieloma Múltiplo/genética , Reação em Cadeia da Polimerase Multiplex , Cromossomos Humanos Par 1/genética , Variações do Número de Cópias de DNA , Humanos , Mieloma Múltiplo/patologia
18.
Pathol Oncol Res ; 30: 1611676, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38818014

RESUMO

The large-scale heterogeneity of genetic diseases necessitated the deeper examination of nucleotide sequence alterations enhancing the discovery of new targeted drug attack points. The appearance of new sequencing techniques was essential to get more interpretable genomic data. In contrast to the previous short-reads, longer lengths can provide a better insight into the potential health threatening genetic abnormalities. Long-reads offer more accurate variant identification and genome assembly methods, indicating advances in nucleotide deflect-related studies. In this review, we introduce the historical background of sequencing technologies and show their benefits and limits, as well. Furthermore, we highlight the differences between short- and long-read approaches, including their unique advances and difficulties in methodologies and evaluation. Additionally, we provide a detailed description of the corresponding bioinformatics and the current applications.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Biologia Computacional/métodos , Genômica/métodos , Análise de Sequência de DNA/métodos
19.
BMC Med Genomics ; 17(1): 30, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38254109

RESUMO

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder which is characterized by the loss of both upper and lower motor neurons in the central nervous system. In a significant fraction of ALS cases - irrespective of family history- a genetic background may be identified. The genetic background of ALS shows a high variability from one ethnicity to another. The most frequent genetic cause of ALS is the repeat expansion of the C9orf72 gene. With the emergence of next-generation sequencing techniques and copy number alteration calling tools the focus in ALS genetics has shifted from disease causing genes and mutations towards genetic susceptibility and risk factors.In this review we aimed to summarize the most widely recognized and studied ALS linked repeat expansions and copy number variations other than the hexanucleotide repeat expansion in the C9orf72 gene. We compare and contrast their involvement and phenotype modifying roles in ALS among different populations.


Assuntos
Esclerose Lateral Amiotrófica , Proteína C9orf72 , Humanos , Esclerose Lateral Amiotrófica/genética , Proteína C9orf72/genética , Variações do Número de Cópias de DNA , Genes Reguladores , Fatores de Risco
20.
Life (Basel) ; 13(3)2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36984004

RESUMO

Rheumatoid arthritis (RA) is a long-term disorder that significantly impairs somatic, emotional, and psychological functioning. The objective of this review is to identify, appraise, and synthesize the effects of psychological interventions (e.g., cognitive behavioral therapy (CBT), emotional disclosure (ED), group therapy (GT), mindfulness (M), patient education (PE), and relaxation (R)) on biopsychosocial outcomes in the treatment of rheumatoid arthritis (RA). A systematic search of all relevant existing randomized clinical trials (RCTs) was conducted using the following online bibliographic databases: JSTOR, PubMed, PsycNET, and The Cochrane Library. Reference lists were searched for additional reports. The Cochrane Risk of Bias tool (RoB 2.0) was used to assess the risk of bias in the included studies. After the selection process, 57 articles were included and 392 were excluded. Three separate meta-analyses were conducted involving psychological interventions as the main variables, showing: (1) significant positive medium effect sizes for average values (Hedges-g = 0.399, Z = 0.399, p = 0.009); (2) significant positive large effect sizes for maximum values (Hedges-g = 0.856, Z = 4.223, p < 0.001); and (3) non-significant results for minimum values (Hedges-g = -0.047, Z = -0.335, p = 0.738). These results demonstrate that, when grouped, psychological interventions are, on average, moderately effective in treating RA. Overall, this review shows consistent, supportive evidence that psychological interventions can significantly contribute to the standard medical care of RA patients. However, more high-quality, large-sample RCTs still need to confirm these findings.

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