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1.
Viruses ; 15(8)2023 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-37632052

RESUMO

Dysregulation of iron metabolism in chronic hepatitis C (CHC) is a significant risk factor for hepatic cirrhosis and cancer. We studied if known genetic variants related to iron homeostasis associate with liver disease progression in CHC. Retrospective analysis included 249 CHC patients qualified for antiviral therapy between 2004 and 2014. For all patients, nine SNPs within HFE, TFR2, HDAC2, HDAC3, HDAC5, TMPRSS6, and CYBRD1 genes were genotyped. Expression of selected iron-related genes, was determined with qRT-PCR in 124 liver biopsies, and mRNA expression of co-inhibitory receptors (PD-1, Tim3, CTLA4) was measured in 79 liver samples. CYBRD1 rs884409, HDAC5 rs368328, TFR2 rs7385804, and TMPRSS6 rs855791 associated with histopathological changes in liver tissue at baseline. The combination of minor allele in HDAC3 rs976552 and CYBRD1 rs884409 linked with higher prevalence of hepatocellular carcinoma (HCC) during follow up (OR 8.1 CI 2.2-29.2; p = 0.001). Minor allele in HDAC3 rs976552 associated with lower hepatic expression of CTLA4. Tested polymorphisms related to iron homeostasis associate with histopathological changes in the liver. The presence of both HDAC3 rs976552 G and CYBRD1 rs884409 G alleles correlates with HCC occurrence, especially in the group of patients with elevated AST (>129 IU/L). rs976552 in HDAC3 could impact immunological processes associated with carcinogenesis in CHC.


Assuntos
Carcinoma Hepatocelular , Hepatite C Crônica , Neoplasias Hepáticas , Humanos , Antígeno CTLA-4 , Hepatite C Crônica/complicações , Hepatite C Crônica/genética , Carcinoma Hepatocelular/genética , Estudos Retrospectivos , Neoplasias Hepáticas/genética , Polimorfismo de Nucleotídeo Único , Homeostase
2.
Materials (Basel) ; 14(9)2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33922291

RESUMO

Doxorubicin, a member of the anthracycline family, is a common anticancer agent often used as a first line treatment for the wide spectrum of cancers. Doxorubicin-based chemotherapy, although effective, is associated with serious side effects, such as irreversible cardiotoxicity or nephrotoxicity. Those often life-threatening adverse risks, responsible for the elongation of the patients' recuperation period and increasing medical expenses, have prompted the need for creating novel and safer drug delivery systems. Among many proposed concepts, polymeric nanocarriers are shown to be a promising approach, allowing for controlled and selective drug delivery, simultaneously enhancing its activity towards cancerous cells and reducing toxic effects on healthy tissues. This article is a chronological examination of the history of the work progress on polymeric nanostructures, designed as efficient doxorubicin nanocarriers, with the emphasis on the main achievements of 2010-2020. Numerous publications have been reviewed to provide an essential summation of the nanopolymer types and their essential properties, mechanisms towards efficient drug delivery, as well as active targeting stimuli-responsive strategies that are currently utilized in the doxorubicin transportation field.

3.
Cancers (Basel) ; 12(11)2020 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-33171788

RESUMO

Liver cirrhosis (LC), contributing to more than 1 million of deaths annually, is a major healthcare concern worldwide. Hepatitis B virus (HBV) is a major LC etiological factor, and 15% of patients with chronic HBV infection (CHB) develop LC within 5 years. Recently, novel host genetic determinants were shown to influence HBV lifecycle and CHB course. DNA repair enzymes can affect dynamics of liver damage and are involved in HBV covalently closed circular DNA (cccDNA) formation, an essential step for viral replication. This study aimed to evaluate the possible role of genes representing key DNA-repair pathways in HBV-induced liver damage. MALDI-TOF MS genotyping platform was applied to evaluate variations within XRCC1, XRCC4, ERCC2, ERCC5, RAD52, Mre11, and NBN genes. Apart from older age (p < 0.001), female sex (p = 0.021), portal hypertension (p < 0.001), thrombocytopenia (p < 0.001), high HBV DNA (p = 0.001), and high aspartate aminotransferase (AST) (p < 0.001), we found that G allele at rs238406 (ERCC2, p = 0.025), T allele at rs25487 (XRCC1, p = 0.012), rs13181 GG genotype (ERCC2, p = 0.034), and C allele at rs2735383 (NBN, p = 0.042) were also LC risk factors. The multivariate logistic regression model showed that rs25487 CC (p = 0.005) and rs238406 TT (p = 0.027) were independently associated with lower risk of LC. This study provides evidence for the impact of functional and potentially functional variations in key DNA-repair genes XRCC1 and ERCC2 in HBV-induced liver damage in a Caucasian population.

4.
Int J Infect Dis ; 96: 260-265, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32387446

RESUMO

OBJECTIVES: The outcomes of hepatitis B virus (HBV) infection vary substantially among affected individuals, providing evidence of the role of host genetic background in the susceptibility to HBV persistence and the dynamics of liver injury progression to cirrhosis and hepatocellular carcinoma (HCC). METHODS: Six single-nucleotide polymorphisms within the interleukin 10 gene (IL10) were genotyped by MALDI-TOF mass spectrometry in 857 patients with chronic HBV infection (CHB), 48 patients with resolved HBV infection, and 100 healthy volunteers. Associations of the selected polymorphisms with susceptibility to chronic HBV infection, liver injury progression, and outcomes were investigated. RESULTS: IL10 -819T (rs1800871), -592A (rs1800872), and +504T (rs3024490) alleles were associated with treatment-induced hepatitis B surface antigen (HBsAg) seroclearance. Additionally, IL10 ATAC haplotype increased the chance of HBsAg loss and was significantly more frequent in patients with less liver injury. Moreover rs1800871TT, rs1518110TT, rs1800872AA, and rs3024490TT genotypes were identified as predictors of a lower FIB-4 score (<0.5). CONCLUSIONS: This study indicates that polymorphisms within the promoter region and intronic sequences of IL10 are associated with chronicity of hepatitis B and with HBV-induced liver damage.


Assuntos
Hepatite B Crônica/genética , Interleucina-10/genética , Adulto , Alelos , Progressão da Doença , Feminino , Genótipo , Antígenos de Superfície da Hepatite B/metabolismo , Hepatite B Crônica/imunologia , Hepatite B Crônica/patologia , Hepatite B Crônica/virologia , Humanos , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único
5.
J Clin Virol ; 120: 1-5, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31505315

RESUMO

BACKGROUND: Hepatitis B virus (HBV) utilizes proteins encoded by the host to infect hepatocytes and replicate. Recently, several novel host factors have been identified and described as important to the HBV lifecycle. The influence of host genetic background on chronic hepatitis B (CHB) pathogenesis is still poorly understood. OBJECTIVES: Here, we aimed to investigate the association of NTCP, FXRα, HNF1α, HNF4α, and TDP2 genetic polymorphisms with the natural course of CHB and antiviral treatment response. STUDY DESIGN: We genotyped 18 single-nucleotide polymorphisms using MALDI-TOF mass spectrometry in 136 patients with CHB and 100 healthy individuals. We investigated associations of the selected polymorphisms with biochemical, serological and hepatic markers of disease progression and treatment response. RESULTS: No significant differences in genotypic or allelic distribution between CHB and control groups were observed. Within TDP2, rs3087943 variations were associated with treatment response, and rs1047782 modified the risk of advanced liver inflammation. Rs7154439 within NTCP was associated with HBeAg seroconversion after 48 weeks of nucleos(t)ide analogue treatment. HNF1α genotypes were associated with treatment response, liver damage and baseline HBeAg presence. HNF4α rs1800961 predicted PEG-IFNα treatment-induced HBsAg clearance in long-term follow up. CONCLUSIONS: This study indicates host genetic background relevance in the course of CHB and confirms the role of recently described genes for HBV infection. The obtained results might serve as a starting point for validation studies on the clinical application of selected genetic variants to predict individual risks of CHB-induced liver failure and treatment response.


Assuntos
Antivirais/uso terapêutico , Proteínas de Ligação a DNA/genética , Hepatite B Crônica/tratamento farmacológico , Fator 1-alfa Nuclear de Hepatócito/genética , Transportadores de Ânions Orgânicos Dependentes de Sódio/genética , Diester Fosfórico Hidrolases/genética , Polimorfismo de Nucleotídeo Único , Simportadores/genética , Adulto , Estudos de Casos e Controles , Feminino , Genótipo , Anticorpos Anti-Hepatite B/metabolismo , Antígenos E da Hepatite B/imunologia , Hepatite B Crônica/genética , Hepatite B Crônica/imunologia , Humanos , Masculino , Soroconversão , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Resultado do Tratamento
6.
Mol Genet Genomic Med ; 7(10): e00935, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31441603

RESUMO

BACKGROUND: Hepatitis B virus (HBV) infections are a major threat worldwide. Disease progression and outcome is diverse and depends on host genetic background. Recently, a high rate of HBV reactivation in individuals receiving tumor necrosis factor-α (TNF-α) antagonists showed the importance of this cytokine in HBV infection control. Here, we investigated the influence of TNF-α promoter polymorphisms on susceptibility to chronic HBV infection (CHB), liver injury progression and outcomes. METHODS: A total of 231 patients with CHB constituted the study group and 100 healthy volunteers-the local control group. TNF-α -1031T/C, -863C/A, -857C/T, -308G/A, and -238G/A were genotyped using MALDI-TOF mass spectrometry. RESULTS: TNF-α -1031C and -863A alleles were observed more frequently in CHB group than in healthy controls. Carriers of TNF-α -1031C and -863A variant alleles had lower baseline levels of serum HBV DNA and lower liver necroinflammatory activity than dominant homozygotes. A -857CT genotype predisposed to higher necroinflammatory activity. No associations between TNF-α variants and liver fibrosis were found. CONCLUSION: This study indicates that TNF-α -863A and -1031C alleles are associated with increased susceptibility to CHB in individuals from northern Poland. The same variants determine the course of CHB, lowering viremia and reducing necroinflammatory activity of the liver.


Assuntos
Hepatite B Crônica/patologia , Fator de Necrose Tumoral alfa/genética , Adulto , Alelos , Povo Asiático/genética , Estudos de Casos e Controles , DNA Viral/sangue , Progressão da Doença , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Vírus da Hepatite B/genética , Vírus da Hepatite B/isolamento & purificação , Hepatite B Crônica/genética , Homozigoto , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas
7.
Maturitas ; 115: 97-102, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30049354

RESUMO

OBJECTIVES: Metabolic syndrome (MS) affects a quarter of Polish people and is associated with diabetes mellitus type 2 and ischemic heart disease. The prevalence of MS in postmenopausal women can be increased by the lack of protective effects of oestrogens. In the near future, because of the general increase in life expectancy, the number of postmenopausal women will rise substantially. Therefore, investigating both the environmental and the genetic factors predisposing to MS may have a great impact on women's health. The aim of this study was to determine whether particular oestrogen receptor (ESR) gene polymorphisms can predispose to the development of MS in women after menopause. STUDY DESIGN: The sample consisted of 147 postmenopausal women. In addition to collecting medical history and analyzing body composition using the TANITA scale, patient's waist size, blood pressure, serum lipids, glucose, insulin, C-reactive protein and adiponectin were measured. The analysis of ESR gene polymorphisms was performed using the Sequenom MassARRAY platform. RESULTS: Three out of ten analyzed polymorphisms in the ESR1 gene (rs2234693, rs6902771, rs7774230) and one out of eight analyzed polymorphisms in the ESR2 gene (rs3020449) were associated with MS. The ESR1 rs2234693, rs6902771 and rs7774230 polymorphisms were associated with serum concentrations of high-density lipoproteins. The ESR2 rs3020449 polymorphism was associated with serum concentrations of total cholesterol and low-density lipoprotein. Four ESR1 polymorphisms (rs1709183, rs2234693, rs6902771, rs7774230) were associated with total fat tissue content. CONCLUSIONS: Bearing the particular alleles at the ESR gene polymorphisms may impact the development of MS and some of the ESR polymorphisms may influence serum cholesterol concentrations in women after menopause.


Assuntos
Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Síndrome Metabólica/genética , Pós-Menopausa/genética , Idoso , Idoso de 80 Anos ou mais , Colesterol/sangue , Feminino , Genótipo , Humanos , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Saúde da Mulher
8.
Curr Pharm Biotechnol ; 19(3): 206-216, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29804530

RESUMO

BACKGROUND: Pentoxifylline (PTX) is a drug commonly used in the treatment of intermittent claudication. However, numerous research groups report that PTX also may potentially be used in the anticancer therapy following one of the main trends in the nowadays medicine - combined anticancer therapy. SCOPE OF REVIEW: The review concentrates on the reports revealing the potential use of PTX in cancer treatment. Major Conclusion: PTX is described to possess several properties which may be exploited in cancer treatment. The drug reportedly not only has anticancer activity itself, but also increases cancer cells susceptibility to radiation therapy and, additionally, reduces long-term side effects of this therapy. Furthermore, numerous research groups report that PTX may increase the anticancer potential of commonly used anticancer drugs such as cisplatin or doxorubicin as well as reduce side effects of these drugs. SIGNIFICANCE: PTX should be considered as a potential drug in the combined anticancer therapy.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Pentoxifilina/uso terapêutico , Animais , Humanos
9.
Colloids Surf B Biointerfaces ; 164: 134-143, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29413590

RESUMO

C60 fullerene is reported to directly interact with biomolecules, such as aromatic mutagens or anticancer drugs. Therefore, it is extensively studied for its potential application in the fields of drug delivery and chemoprevention. Understanding the nature of fullerene-drugs interactions might contribute to optimization and modification of the existing chemotherapy systems. Possible interactions between ICR-191, a model acridine mutagen, with well-established biophysical properties and mutagenic activity, and C60 fullerene aqueous solution were investigated by broad range of biophysical methods, such as Dynamic Light Scattering, Isothermal Titration Calorimetry, and Atomic Force Microscopy. Additionally, to determine biological activity of ICR-191-C60 fullerene mixtures, Ames mutagenicity test was employed. It was demonstrated that C60 fullerene interacts non-covalently with ICR-191 and has strong affinity to bacterial membranes. The obtained results provide practical insight into C60 fullerene interactions with aromatic compounds.


Assuntos
Fulerenos/química , Hidrocarbonetos Aromáticos/metabolismo , Aminacrina/análogos & derivados , Aminacrina/metabolismo , Transporte Biológico , Fenômenos Biofísicos , Microscopia de Força Atômica , Modelos Moleculares , Mutagênicos/toxicidade , Compostos de Mostarda Nitrogenada/metabolismo , Salmonella typhimurium/efeitos dos fármacos
10.
Emerg Microbes Infect ; 6(6): e55, 2017 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-28634352

RESUMO

The hepatitis B virus (HBV) genome exists in two forms: circular covalently closed DNA (cccDNA) and relaxed circular DNA (RCDNA). Here, we investigated the presence of differences in the sequences of both forms in paired samples of serum and liver tissue. The serum and liver biopsy samples were collected at the same time from 67 chronically infected patients. The genotyping of the RCDNA and cccDNA was performed using mass spectrometry analysis. The HBV mutations located in the HBV pol (P) and the HBV basal core promoter/pre-core (BCP/PC) regions were included. The BCP/PC and P sequences of the RCDNA extracted from liver and blood samples were different in 39% and 16% of patients, respectively. Differences were also found between RCDNA and cccDNA extracted from the same liver specimen. Moreover, the cccDNA BCP/PC region sequence had an impact on various virological and clinical parameters. We demonstrated that there are differences between the RCDNA and cccDNA sequences that were extracted from the same liver tissue. However, further investigations are needed to analyze whether the mutations in the cccDNA are conserved and whether cccDNA serves as a 'mutation storage' pool for HBV. This result could have profound implications for the subsequent therapy choices for treatment-experienced patients.


Assuntos
DNA Circular , DNA Viral/sangue , Vírus da Hepatite B/genética , Análise de Sequência de DNA , Adolescente , Adulto , Biópsia , Feminino , Genoma Viral , Técnicas de Genotipagem , Hepatite B Crônica/sangue , Hepatite B Crônica/virologia , Humanos , Fígado/patologia , Fígado/virologia , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Mutação , Polimorfismo Genético , Regiões Promotoras Genéticas , Adulto Jovem
11.
J Gastroenterol Hepatol ; 32(2): 482-486, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27439017

RESUMO

BACKGROUND AND AIM: Pathological iron overload is commonly found in chronic hepatitis C (CHC) patients and considered as a negative prognostic factor of the disease. A single nucleotide polymorphism (SNP) rs884409 in duodenal cytochrome b gene (CYBRD1) is implicated in the pathogenesis of hemochromatosis. In our study we investigated the impact of the CYBRD1 genotype and expression on iron overload in CHC patients. METHODS: Liver biopsy specimens and whole blood samples from 243 patients with CHC were included in the study. Iron deposits in hepatocytes, serum markers of iron overload, and expression profile of gene-regulators of iron homeostasis were analyzed. Genotyping and analysis of gene expression of the CYBRD1 were performed. The frequency of SNP and the expression levels of CYBRD1 were compared between the groups of patients with and without markers of iron overload. RESULTS: The single nucleotide variant rs884409 G was associated with elevated serum iron levels, increased markers of liver inflammation, and oxidative stress. Hepatic expression of CYBRD1 was associated with the expression of Tfr2, Id1, and HO-1 genes, serum ferritin levels, and with increased iron accumulation in liver. CONCLUSION: These results implicate CYBRD1 involvement in iron homeostasis in CHC.


Assuntos
Grupo dos Citocromos b/genética , Hepatite C Crônica/metabolismo , Ferro/metabolismo , Fígado/metabolismo , Oxirredutases/genética , Polimorfismo de Nucleotídeo Único , Grupo dos Citocromos b/metabolismo , Feminino , Expressão Gênica/genética , Hemocromatose/genética , Humanos , Sobrecarga de Ferro/genética , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/genética , Oxirredutases/metabolismo
12.
Clin Exp Med ; 17(2): 225-232, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27125837

RESUMO

Single nucleotide polymorphisms (SNPs) within DNA region containing interferon lambda 3 (IFNL3) and IFNL4 genes are prognostic factors of treatment response in chronic hepatitis C (CHC). Iron overload, frequently diagnosed in CHC, is associated with unfavorable disease course and a risk of carcinogenesis. Its etiology and relationship with the immune response in CHC are not fully explained. Our aim was to determine whether IFNL polymorphisms in CHC patients associate with body iron indices, and whether they are linked with hepatic expression of genes involved in iron homeostasis and IFN signaling. For 192 CHC patients, four SNPs within IFNL3-IFNL4 region (rs12979860, rs368234815, rs8099917, rs12980275) were genotyped. In 185 liver biopsies, histopathological analyses were performed. Expression of five mRNAs and three long non-coding RNAs (lncRNAs) was determined with qRT-PCR in 105 liver samples. Rs12979860 TT or rs8099917 GG genotypes as well as markers of serum and hepatocyte iron overload associated with higher activity of gamma-glutamyl transpeptidase and liver steatosis. The presence of two minor alleles in any of the tested SNPs predisposed to abnormally high serum iron concentration and correlated with higher hepatic expression of lncRNA NRIR. On the other hand, homozygosity in any major allele associated with higher viral load. Patients bearing rs12979860 CC genotype had lower hepatic expression of hepcidin (HAMP; P = 0.03). HAMP mRNA level positively correlated with serum iron indices and degree of hepatocyte iron deposits. IFNL polymorphisms influence regulatory pathways of cellular response to IFN and affect body iron balance in chronic hepatitis C virus infection.


Assuntos
Hepatite C Crônica/complicações , Interleucinas/genética , Sobrecarga de Ferro/genética , Polimorfismo de Nucleotídeo Único , Adulto , Biópsia , Feminino , Perfilação da Expressão Gênica , Genótipo , Hepatite C Crônica/patologia , Histocitoquímica , Humanos , Interferons , Sobrecarga de Ferro/patologia , Fígado/patologia , Masculino , Pessoa de Meia-Idade , RNA Longo não Codificante/biossíntese , Reação em Cadeia da Polimerase em Tempo Real
13.
Bioorg Chem ; 65: 118-25, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26921593

RESUMO

Anticancer drug idarubicin - derivative of doxorubicin - is commonly used in treatment of numerous cancer types. However, in contrast to doxorubicin, its biophysical properties are not well established yet. Additionally, potential direct interactions of idarubicin with other biologically active aromatic compounds, such as pentoxifylline - representative of methylxanthines - were not studied at all. Potential formation of such hetero-aggregates may result in sequestration of the anticancer drug and, in consequence, reduction of its biological activity. This work provide description of the idarubicin biophysical properties as well as assess influence of pentoxifylline on idarubicin interactions with DNA. To achieve these goals we employed spectrophotometric methods coupled with analysis with the appropriate mathematical models as well as flow cytometry and Ames test. Obtained results show influence of pentoxifylline on idarubicin binding to DNA and are well in agreement with the data previously published for other aromatic ligands. Additionally it may be hypothesized that direct interactions between idarubicin and pentoxifylline may influence the anticancer drug biological activity.


Assuntos
Antineoplásicos/química , DNA/química , Idarubicina/química , Pentoxifilina/química , Pentoxifilina/farmacologia , Animais , Sítios de Ligação/efeitos dos fármacos , Bovinos , Estrutura Molecular , Ligação Proteica/efeitos dos fármacos
14.
Biochimie ; 123: 95-102, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26855172

RESUMO

Anticancer drug doxorubicin is commonly used in cancer treatment. However, drug's severe side effects make toxicity reduction important matter. Another biologically active aromatic compound, pentoxifylline, can sequester aromatic compounds in stacking complexes reducing their bioactivity. This work deals with the problem of alleviating doxorubicin side effects by pentoxifylline. We employed a wide spectrum of prokaryotic and eukaryotic cellular assays. In addition, we used the doxorubicin-pentoxifylline mixed association constant to quantitatively assess pentoxifylline influence on the doxorubicin mutagenic activity. Obtained results indicate strong protective effects of pentoxifylline towards doxorubicin, observed on bacteria and human keratinocytes with no such effects observed on the cancer cells. It may be hypothesized that, considering much shorter half-life of pentoxifylline than doxorubicin, simultaneous administration of doxorubicin and pentoxifylline will lead to gradual release of doxorubicin from complexes with pentoxifylline to reach desired therapeutic concentration. Proposed results shed light on the possible doxorubicin chemotherapy modification and its side effects reduction without the loss of its therapeutic potential.


Assuntos
Antibióticos Antineoplásicos/farmacologia , DNA/metabolismo , Doxorrubicina/farmacologia , Pentoxifilina/farmacologia , Linhagem Celular , Humanos , Microscopia Confocal
15.
Chem Biol Interact ; 242: 291-8, 2015 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-26499448

RESUMO

Pentoxifylline--biologically active aromatic compound--has a well established capability to sequester aromatic ligands, such as an anticancer drug--doxorubicin--in mixed stacking aggregates. Formation of such hetero-complexes may influence biological activity of secluded drug. Presented work shows assessment of pentoxifylline influence on doxorubicin direct interactions with DNA employing biophysical methods. Achievement of this goal required statistical-thermodynamical model allowing numerical four-parameter analysis of experimental mixture--an issue that was successfully tackled by merging McGhee--von Hippel and Kapuscinski--Kimmel models. Results obtained with new model are well in agreement with data obtained with separate experiments with each of these two models and show reduction of doxorubicin in free (monomeric, dimeric) and complexed with DNA forms in favor of doxorubicin-pentoxifylline complexes with increasing pentoxifylline concentration. Developed model appears to be a universal tool allowing numerical analysis of mixtures containing self-aggregating ligand, DNA, and modulating agent.


Assuntos
Antineoplásicos/metabolismo , DNA/metabolismo , Doxorrubicina/metabolismo , Pentoxifilina/farmacologia , Animais , Antineoplásicos/farmacologia , Bovinos , Doxorrubicina/farmacologia , Interações Medicamentosas , Termodinâmica
16.
Bioorg Med Chem ; 21(11): 3280-9, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23601817

RESUMO

Caffeine (CAF) and other methylxanthines (MTX) may interact directly with several aromatic, intercalating ligands through mixed stacking aggregation. Formation of such stacking hetero-complexes may decrease their free form concentration and, in consequence, diminish their biological activity, which is often related to their direct interaction with DNA. In this paper interactions of acridine mutagen (ICR191) with DNA in the presence of three MTX: caffeine (CAF), pentoxifylline (PTX) and theophylline (TH) are investigated. Several mathematical models are used to calculate all association constant values and every component concentration in each analyzed mixture. Model McGhee-von Hippel is used to analyze ligand-DNA interaction, and model Zdunek et al.--to analyze ligand-MTX interactions. Finally, two distinct mathematical models are employed to analyze three-component mixture containing ligand, MTX and DNA molecules. The first model describes possible interactions of ligand with DNA and MTX, and rejects direct MTX interactions with DNA. The second model describes all interactions mentioned above and, additionally, allows MTX to interact directly with DNA. Results obtained using these models are similar. However, correspondence of theoretical results to experimental data is better for the first model than the second one. In this paper possible interactions of ICR191 with eukaryotic cell chromatin are also analyzed, showing that CAF reduces acridine mutagen potential to interact directly with cell chromatin. Additionally, it is demonstrated that MTX inhibit mutagenic activity of ICR191 in a dose-dependent manner. Furthermore, biological activity of ICR191-MTX mixtures corresponds with concentration of free mutagen form calculated using appropriate mathematical model.


Assuntos
Aminacrina/análogos & derivados , Cafeína/química , DNA/química , Substâncias Intercalantes/química , Mutagênicos/química , Compostos de Mostarda Nitrogenada/química , Pentoxifilina/química , Teofilina/química , Aminacrina/química , Aminacrina/farmacologia , Animais , Cafeína/farmacologia , Bovinos , Antagonismo de Drogas , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Substâncias Intercalantes/farmacologia , Rim/citologia , Rim/efeitos dos fármacos , Cinética , Modelos Químicos , Mutagênicos/farmacologia , Compostos de Mostarda Nitrogenada/farmacologia , Pentoxifilina/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Teofilina/farmacologia , Termodinâmica
17.
Bioorg Chem ; 39(1): 10-7, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21146849

RESUMO

Methylxanthines (MTX), in particular caffeine (CAF), are known as the most widely consumed alkaloids worldwide. Many accumulated statistical data indicate the protective effect of CAF intake against several types of cancer. One of the possible explanations of this phenomenon is direct non-covalent interaction between CAF and aromatic mutagen/carcinogen molecules through stacking (π-π) complexes formation. Here we demonstrate that CAF and other MTX, pentoxifylline (PTX) and theophylline (TH), form stacking complexes with carcinogenic imidazoquinoline-type (IQ-type) food-borne heterocyclic aromatic amines (HCAs). We estimated neighborhood association constants (K(AC) of the order of magnitude of 10(2)M(-1)) in neutral and acidic environment and enthalpy changes (ΔH values between -15.1 and -39.8kJ/mol) for these interactions using UV-Vis spectroscopy, calculations based on thermodynamical model of mixed aggregation and titration microcalorimetry. Moreover, using Ames test with Salmonella typhimurium TA98 strain and recently developed mutagenicity assay based on bioluminescence of Vibrio harveyi A16 strain, we demonstrated a statistically significant reduction in HCAs mutagenic activity in the presence of MTX.


Assuntos
Aminas/química , Cafeína/química , Carcinógenos/química , Compostos Heterocíclicos/química , Pentoxifilina/química , Teofilina/química , Aminas/farmacologia , Cafeína/farmacologia , Calorimetria , Carcinógenos/farmacologia , Compostos Heterocíclicos/farmacologia , Testes de Mutagenicidade , Pentoxifilina/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Análise Espectral , Teofilina/farmacologia , Vibrio/efeitos dos fármacos , Xantinas/química , Xantinas/farmacologia
18.
Postepy Biochem ; 56(4): 435-46, 2010.
Artigo em Polonês | MEDLINE | ID: mdl-21473048

RESUMO

It is estimated that diet contributes to as much as one-third of cancer incidents. Heterocyclic aromatic amines (HCAs) are well-known mutagens/carcinogens found in thermal-processed meat and fish. HCAs require metabolic activation to exert their carcinogenic potential. First step in HCAs activation--the generation of N-hydroxy-HCA derivatives--is catalyzed by cytochrome P450, mainly isoenzyme CYP1A2. Further activation is carried out by N-acetyltransferases and sulfotransferases, which catalyze esterification of N-hydroxy-HCAs. The products of these reactions are highly genotoxic, capable of direct interaction with DNA by adduct formation. HCA-DNA adducts may cause errors in DNA replication and the generation of mutations, which, when not repaired, may contribute to cancer development. On the other hand, among enzymes involved in HCAs detoxication, UDP-glucuronosyltransferases and glutathione S-transferases can be mentioned. Balance between activation and detoxication processes of HCAs, together with genetically determined differences in HCA metabolism are crucial for the assessment of HCA-dependent cancer risk among individuals.


Assuntos
Alimentos/toxicidade , Mutagênicos/metabolismo , Neoplasias/etiologia , Neoplasias/metabolismo , Acetiltransferases/metabolismo , Animais , Biotransformação , Culinária , Citocromo P-450 CYP1A2/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Adutos de DNA/biossíntese , Dano ao DNA , Suscetibilidade a Doenças , Compostos Heterocíclicos/toxicidade , Humanos , Mutação , Neoplasias/genética , Sulfotransferases/metabolismo
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