RESUMO
BACKGROUND: Osteosarcoma (OS), the most common bone tumor in children and adolescents, has high rates of metastasis leading to poor survival. Leucine-rich repeat containing 15 (LRRC15), a transmembrane protein whose expression is modulated by TGFß, was recently shown to be highly expressed on the surface of OS tumor cells. Here, we evaluate a novel antibody-drug conjugate (ADC) targeting LRRC15 in OS human cell lines and murine xenografts. We compare this new ADC, which is conjugated to the anthracycline derivative PNU-159682 (PNU), to a previously studied LRRC15 ADC that is conjugated to the tubulin inhibitor monomethyl auristatin E (MMAE), since anthracyclines are standard of care in OS. PROCEDURE: We evaluated LRRC15 expression in OS cells using Western blots and flow cytometry, and analyzed the epigenetic landscape of the LRRC15 locus using chromatin immunoprecipitation. Efficacy of ADCs on cell growth was analyzed by IncuCyte live cell imaging. Intramuscular xenograft tumor growth was assessed by bioluminescence imaging and hematoxylin and eosin staining. RESULTS: LRRC15-PNU is more effective at inhibiting growth in vitro and in vivo than an isotype antibody control or the LRRC15-MMAE ADC in two high LRRC15 expressing OS cell lines. Low expressing cell lines are not sensitive to either ADC. Importantly, cells with low LRRC15 expression are amenable to re-expression after TGFß treatment, suggesting a potential to sensitize insensitive OS cells to LRRC15 ADC treatment. In vivo, LRRC15-PNU had cure rates of 40-100% in OS xenograft models. CONCLUSIONS: Overall, LRRC15-directed ADCs are a promising new avenue for OS treatment.
Assuntos
Antineoplásicos/farmacologia , Doxorrubicina/análogos & derivados , Imunoconjugados/farmacologia , Proteínas de Membrana/antagonistas & inibidores , Osteossarcoma/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Doxorrubicina/farmacocinética , Doxorrubicina/farmacologia , Humanos , Camundongos , Camundongos SCID , Metástase Neoplásica/tratamento farmacológico , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Moduladores de Tubulina/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Aberrant methylation is a known cause of cancer initiation and/or progression. There are scant data on the genome-wide methylation pattern of nonfunctioning pancreatic neuroendocrine tumors (NFPanNETs) and sporadic and hereditary NFPanNETs. METHODS: Thirty-three tissue samples were analyzed: they included samples from sporadic (n = 9), von Hippel-Lindau (VHL)-related (n = 10), and multiple endocrine neoplasia type 1 (MEN1)-related NFPanNETs (n = 10) as well as normal islet cells (n = 4) for comparison. Genome-wide CpG methylation profiling was performed with the Infinium MethylationEPIC BeadChip assay and was analyzed with R-based tools. RESULTS: In unsupervised hierarchical clustering, sporadic and MEN1-related NFPanNETs clustered together, and the VHL group was in a separate cluster. MEN1-related NFPanNETs had a higher rate of hypermethylated CpG sites in comparison with sporadic and VHL-related tumor groups. Differentially methylated region analysis confirmed the higher rate of hypermethylation in MEN1-related tumors. Moreover, in an integrated analysis of gene expression data for the same tumor samples, downregulated gene expression was found in most genes that were hypermethylated. In a CpG island methylator phenotype analysis, 3 genes were identified and confirmed to have downregulated gene expression: secreted frizzle-related protein 5 (SFRP5) in sporadic NFPanNETs and cell division cycle-associated 7-like (CDCA7L) and RNA binding motif 47 (RBM47) in MEN1-related NFPanNETs. CONCLUSIONS: MEN1 NFPanNETs have a higher rate of geno me-wide hypermethylation than other NFPanNET subtypes. The similarity between the pathways enriched in a methylation analysis of known genes involved in NFPanNET tumorigenesis suggests a key role for aberrant methylation in the pathogenesis of NFPanNETs.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Carcinoma Neuroendócrino/classificação , Metilação de DNA , Neoplasias Pancreáticas/classificação , Proteínas de Ligação a RNA/genética , Proteínas Repressoras/genética , Sequenciamento Completo do Genoma/métodos , Carcinoma Neuroendócrino/genética , Ilhas de CpG , Regulação para Baixo , Epigênese Genética , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pancreáticas/genética , Proteínas Proto-Oncogênicas/genética , Aprendizado de Máquina não Supervisionado , Proteína Supressora de Tumor Von Hippel-Lindau/genéticaRESUMO
There are numerous examples of parental transgenerational inheritance that is epigenetic. The informational molecules include RNA, chromatin modifications, and cytosine methylation. With advances in DNA sequencing technologies, the molecular and epigenetic mechanisms mediating these effects are now starting to be uncovered. This mini-review will highlight some of the examples of epigenetic inheritance, the establishment of cytosine methylation in sperm, and recent genomic studies linking sperm cytosine methylation to epigenetic effects on offspring. A recent paper examining changes in diet and sperm cytosine methylation from pools of eight animals each, found differences between a normal diet, a high fat diet, and a low protein diet. However, epivariation between individuals within a group was greater than the differences between groups obscuring any potential methylation changes linked to diet. Learning more about epivariation may help unravel the mechanisms that regulate cytosine methylation. In addition, other experimental and genetic systems may also produce more dramatic changes in the sperm methylome, making it easier to unravel potential transgenerational phenomena. J. Cell. Physiol. 231: 2346-2352, 2016. © 2016 Wiley Periodicals, Inc.
Assuntos
Citosina/metabolismo , Metilação de DNA/genética , Padrões de Herança/genética , Animais , Dieta , Humanos , Nucleossomos/metabolismo , FenótipoRESUMO
Early detection and quantification of DNA damage in oral premalignancy or malignancy may help in management of the disease and improve survival rates. The comet assay has been successfully utilised to detect DNA damage in oral premalignant or malignancy. However, due to the invasive nature of collecting blood, it may be painful for many unwilling patients. This study compares the micronucleus (MN) assay in oral buccal mucosa cells with the comet assay in peripheral blood cells in a subset of oral habit-induced precancer and cancer patients. For this, MN assay of exfoliated epithelial cells was compared with comet assay of peripheral blood leucocytes among 260 participants, including those with oral lichen planus (OLP; n = 52), leukoplakia (LPK; n = 51), oral submucous fibrosis (OSF; n = 51), oral squamous cell carcinoma (OSCC; n = 54) and normal volunteers (n = 52). Among the precancer groups, LPK patients showed significantly higher levels of DNA damage as reflected by both comet tail length (P < 0.0001) and micronuclei (MNi) frequency (P = 0.0009). The DNA damage pattern in precancer and cancer patients was OLP < OSF < LPK < OSCC, and with respective oral habits, it was multiple habits > cigarette + khaini > cigarette smokers > areca + khaini > areca. There was no significant difference in the comet length and MNi frequency between males and females who had oral chewing habits. An overall significant correlation was observed between MNi frequency and comet tail length with r = 0.844 and P < 0.0001. Thus, the extent of DNA damage evaluation by the comet assay in peripheral blood cells is perfectly reflected by the MN assay on oral exfoliated epithelial cells, and MNi frequency can be used with the same effectiveness and greater efficiency in early detection of oral premalignant conditions.
Assuntos
Ensaio Cometa , Dano ao DNA , Testes para Micronúcleos , Mucosa Bucal/patologia , Neoplasias Bucais/genética , Adulto , Estudos de Casos e Controles , Progressão da Doença , Células Epiteliais/metabolismo , Feminino , Humanos , Leucócitos Mononucleares/metabolismo , Leucoplasia/genética , Leucoplasia/patologia , Líquen Plano Bucal/genética , Líquen Plano Bucal/patologia , Masculino , Mucosa Bucal/citologia , Neoplasias Bucais/patologia , Fibrose Oral Submucosa/genética , Fibrose Oral Submucosa/patologia , Adulto JovemRESUMO
BACKGROUND: Proper expression and functioning of transcription factors (TFs) are essential for regulation of different traits and thus could be crucial for the development of complex diseases. Subjects with Down syndrome (DS) have a higher incidence of acute lymphoblastic leukemia (ALL) while solid tumors, like breast cancer (BC) and oral cancer (OC), show rare incidences. Triplication of the human chromosome 21 in DS is associated with altered genetic dosage of different TFs. V-ets erythroblastosis virus E26 oncogene homolog 2 (ETS2) and Single Minded 2 (SIM2) are two such TFs that regulate several downstream genes involved in developmental and neurological pathways. Here we studied functional genetic polymorphisms (fSNP) in ETS2 and SIM2 encoding genes in a group of patients and control subjects to better understand association of these variants with DS phenotypes. METHODS: We employed an in silico approach to identify potential target pathways of ETS2 and SIM2. fSNPs in genes encoding for these two TFs were identified using available databases. Selected sites were genotyped in individuals with DS, their parents, ALL, BC, OC as well as ethnically matched control individuals. We further analyzed these data by population-based statistical methods. RESULTS: Allelic/genotypic association analysis showed significant (P < 0.03) differences of rs2070530, rs1051476, rs11254, rs711 for DS subjects compared to control. rs711 also exhibited significantly different genotypic distribution pattern in parents of DS probands (P < 0.02) and BC patients (P < 0.02). Interaction analysis revealed independent main effect of rs711 in all the groups, while rs11254 exhibited independent main effect in DS subjects only. High entropy values were noticed for rs461155 in the solid tumor groups. Significant interactive effects of rs2070531 with rs1051475, rs1051476, rs11254 were observed in all the groups except DS. CONCLUSIONS: We infer from the present investigation that the difference in frequencies of fSNPs and their independent as well as interactive effects may be the cause for altered expression of SIM2 and ETS2 in DS and malignant groups, which affects different downstream biological pathways. Thus, altered expression of SIM2 and ETS2 could be one of the reasons for variable occurrence of different malignant conditions in DS.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Síndrome de Down/complicações , Síndrome de Down/genética , Polimorfismo de Nucleotídeo Único , Proteína Proto-Oncogênica c-ets-2/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Neoplasias da Mama/etiologia , Neoplasias da Mama/genética , Estudos de Casos e Controles , Simulação por Computador , Epistasia Genética , Feminino , Frequência do Gene , Haplótipos/genética , Humanos , Índia , Desequilíbrio de Ligação , Neoplasias Bucais/etiologia , Neoplasias Bucais/genética , Linhagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/etiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteína Proto-Oncogênica c-ets-2/metabolismoRESUMO
CONTEXT: The detrimental effects of arsenic on female reproductive functions may involve overt oxidative stress. Casein and pea [Pisum sativum Linn. (Fabaceae)] proteins have antioxidant properties. OBJECTIVE: To investigate the role of casein- and pea-supplemented high-protein diet (HPD) in utero-ovarian protection from arsenic toxicity. MATERIALS AND METHODS: Adult female Wistar rats were orally gavaged with vehicle (Gr-I) or arsenic at 3 ppm/rat/d (Gr-II and Gr-III) for 30 consecutive days, when they were maintained on either regular diet containing 18% protein (Gr-I and Gr-II), or HPD containing 27% protein in the form of casein (20%) and pea (7%) (Gr-III). Reproductive functions were evaluated using a battery of biochemical and histological techniques. RESULTS: As compared to Gr-I, the Gr-II rats suffered from loss of estrous cyclicity, reduction in weight (mg/100 g body weight) of ovary (Gr-I: 54.3 ± 4.2 versus Gr-II: 35.8 ± 1.6; p < 0.001) and uterus (Gr-I: 161.7 ± 24.6 versus Gr-II: 94.44 ± 13.2; p < 0.05), utero-ovarian degeneration, attenuated ovarian activities (unit/mg tissue/h) of Δ(5), 3ß-hydroxysteroid dehydrogenase (Gr-I: 3.41 ± 0.12 versus Gr-II: 2.31 ± 0.09; p < 0.01) and 17ß-hydroxysteroid dehydrogenase (Gr-I: 3.82 ± 0.57 versus Gr-II: 1.24 ± 0.19; p < 0.001), and decreased serum estradiol level (pg/ml) (Gr-I: 61.5 ± 2.06 versus 34.1 ± 2.34; p < 0.001). Ovarian DNA damage was preponderant with blatant generation of malondialdehyde (nM/mg tissue; Gr-I: 15.10 ± 2.45 versus Gr-II: 29.51 ± 3.44; p < 0.01) and attenuated superoxide dismutase activity (unit/mg tissue) (Gr-I: 2.18 ± 0.19 versus Gr-II: 1.33 ± 0.18; p < 0.05). The Gr-III rats were significantly protected from these ill effects of arsenic. DISCUSSION AND CONCLUSION: HPD, by way of antioxidant properties, may find prospective role in the protection of reproductive damage caused by arsenic.
Assuntos
Caseínas/administração & dosagem , Poluentes Ambientais/toxicidade , Ovário/efeitos dos fármacos , Óxidos/toxicidade , Pisum sativum , Proteínas de Vegetais Comestíveis/administração & dosagem , Reprodução/efeitos dos fármacos , Útero/efeitos dos fármacos , 17-Hidroxiesteroide Desidrogenases/metabolismo , 3-Hidroxiesteroide Desidrogenases/metabolismo , Ração Animal , Animais , Trióxido de Arsênio , Arsenicais , Peso Corporal , Citoproteção , Dano ao DNA , Ingestão de Alimentos , Estradiol/sangue , Ciclo Estral/efeitos dos fármacos , Feminino , Malondialdeído/metabolismo , Tamanho do Órgão , Ovário/metabolismo , Ovário/patologia , Ovário/fisiopatologia , Estresse Oxidativo , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Útero/metabolismo , Útero/patologia , Útero/fisiopatologiaRESUMO
BACKGROUND: Arecanut and smokeless tobacco usage is a major cause for oral submucous fibrosis (OSF) and its subsequent development to oral squamous cell carcinoma in South-east Asian population. Polymorphisms at N-acetyltransferase 2 locus, coding for an enzyme catalyzing acetylation of aromatic amines, might cause DNA adduct formation because of improper acetylation of these polyaromatic hydrocarbons. DNA repair enzymes remove these adduct to prevent malignancy. METHODS: In this hospital-based study, 100 controls and 88 OSF patients were genotyped at four polymorphic sites on NAT2 481 (C > T; silent), 590 (G > A; Arg197 > Gln), 803 (A > G; Lys268 > Arg), 857 (G > A; Gly286 > Glu) and two on XRCC1 18067 (C > T Arg 194 > Trp), 28152 (G > A Arg 399 > Gln), and one of XRCC3 26304 (C > T Thr 241 > Met) loci by PCR-RFLP to determine the risk of the disease. RESULTS: Heterozygous XRCC3 codon 241 [OR 2.07 (1.05-4.06)], homozygous variant of NAT C481T [OR 2.81 (1.09-7.21)], and both heterozygous and homozygous variants of NAT codon 268 and 286 [OR 2.31 (1.20-4.45) and 4.98 (1.87-13.14), and 6.12 (2.75-13.62) and 2.65 (1.04-6.72)] individually influenced susceptibility to OSF in the population. CONCLUSION: Gene-gene interaction analysis by multifactor dimensionality reduction (MDR) revealed that XRCC3 Thr 241 Met had the largest univariate effect followed by XRCC3 Thr 241 Met - NAT2 A857G in men that presents a highly synergistic interaction as one of the potential combinations of single nucleotide polymorphisms (SNPs) to increase the risk of OSF in men if exposed to arecanut or smokeless tobacco usage. These observations can speculate the impact of the studied SNPs on the etiology of OSF.
Assuntos
Arilamina N-Acetiltransferase/genética , Reparo do DNA/genética , Proteínas de Ligação a DNA/genética , Fibrose Oral Submucosa/genética , Polimorfismo Genético/genética , Adulto , Areca/efeitos adversos , Arginina/genética , Estudos de Casos e Controles , Códon/genética , Feminino , Predisposição Genética para Doença/genética , Ácido Glutâmico/genética , Glutamina/genética , Glicina/genética , Heterozigoto , Homozigoto , Humanos , Índia , Lisina/genética , Masculino , Metionina/genética , Redução Dimensional com Múltiplos Fatores , Fibrose Oral Submucosa/enzimologia , Polimorfismo de Fragmento de Restrição/genética , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco , Treonina/genética , Tabaco sem Fumaça/efeitos adversos , Triptofano/genética , Proteína 1 Complementadora Cruzada de Reparo de Raio-XRESUMO
The antimicrobial efficacy of methylglyoxal (MG) against several gram-negative bacteria including Escherichia coli has been reported. To determine the mechanism of action of MG, molecular interactions between lipid and MG within the liposomal membrane were also investigated. Multilamellar and unilamellar vesicles were prepared from 1, 2-dipalmitoyl-snglycero-3-phosphocholine (DPPC). The effect of MG on DPPC liposomal membrane was studied by fluorescence spectroscopy and differential scanning calorimetry. The results indicate that MG interacts mainly with the DPPC head group that produces a significant increase in the fluidity of liposomal vesicles, which could be the cause of a fusion/aggregation effect in microbial cells. The agarose gel electrophoresis study with the genomic DNA extracted from E. coli ATCC 25922 revealed that addition of MG could completely degrade this DNA within 1 h, pointing out to their distinctly high degree of sensitivity towards MG. Further, the drug was able to cross the cell membranes, penetrating into the interior of the cell and interacting with DNA for demonstrating antibacterial activity of MG.
Assuntos
Antibacterianos/farmacologia , Biomimética , DNA Bacteriano/metabolismo , Membranas Artificiais , Aldeído Pirúvico/farmacologia , Varredura Diferencial de Calorimetria , Eletroforese em Gel de Ágar , Escherichia coli/genética , Espectrometria de FluorescênciaRESUMO
BACKGROUND: Oral submucous fibrosis (OSF) is a debilitating collagen-metabolic disorder leading to submucosal fibrosis and trismus. Lysyl oxidase (LOX), a critical collagen biosynthetic enzyme, is up-regulated in OSF. Polymorphisms in the Lysyl oxidase gene have been associated with increased risk of OSF and might affect normal collagen synthesis, accumulation, or degradation, crucial in determining fibrosis severity. METHODS: One hundred OSF cases and 100 controls were genotyped for LOX G473A(Arg158Gln) polymorphism by polymerase chain reaction-restriction fragment length polymorphism. The expression of LOX was estimated both by quantitative mRNA analysis and western blot. Total soluble collagen was evaluated from mucosal tissue obtained from OSF cases. Immunohistochemical (IHC) localization of type 1 collagen was performed in mucosal tissue obtained from patients carrying various genotypes. RESULTS: Heterozygous G473A genotype was significantly higher in OSF cases [2.063(95% CI =1.059-4.016)], among 26-40 years age-group [4.375(95% CI=1.323-14.267),p=0.029] and in male patients [2.38 (95% CI= 1.107-5.121), p= 0.042]. LOX expression was significantly higher in cases of the heterozygous or homozygous carrier (p <0.001). We found the total soluble collagen level significantly (p <0.001) higher among patients carrying GA or AA genotype. IHC revealed focal deposition of type1 collagen in the submucosal tissue; comparatively higher deposition was evident in mucosal tissue of OSF patients carrying AA genotype. CONCLUSIONS: These findings suggest LOX G473A polymorphism confers an increased risk of OSF and may affect collagen accumulation in OSF cases.
Assuntos
Colágeno/metabolismo , Predisposição Genética para Doença , Fibrose Oral Submucosa/patologia , Polimorfismo de Nucleotídeo Único , Proteína-Lisina 6-Oxidase/genética , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Índia/epidemiologia , Lactente , Recém-Nascido , Masculino , Fibrose Oral Submucosa/epidemiologia , Fibrose Oral Submucosa/genética , Fibrose Oral Submucosa/metabolismo , Prognóstico , Fatores de Risco , Adulto JovemRESUMO
V-ets erythroblastosis virus E26 oncogene homolog2 (ETS2), located at chromosome 21 and overexpressed in Down's syndrome (DS), has known cancer regulatory functions. Because leukemia is of common occurrence in DS subjects while solid tumors are rare, we have explored the role of ETS2 functional genetic polymorphisms in this differential oncological development. In silico methods were used for identifying deleterious SNPs, tagged SNPs, and linkage disequilibrium followed by genotyping of 14 SNPs in Indo-Caucasoid individuals (N=668). Significantly different allelic frequencies for rs457705, rs1051420, and rs1051425 were observed in Indian controls (N=149) compared to other ethnic groups. A heterozygous "T" insertion, between chromosomal contig positions 40195541 and 40195542, was observed in DS subjects and their parents. rs461155 showed significant allelic and genotypic association in breast and oral cancer patients. Significantly higher occurrence of G-C haplotype (rs461155-rs1051425) was also observed in these patients compared to DS and leukemic patients. This is the first report on this type of allelic discrimination pattern of ETS2 under different disease conditions. From the data obtained it may be proposed that allelic discrimination of deleterious SNPs in ETS2 may play a regulatory role in the differential development of malignancy in DS subjects.
Assuntos
Síndrome de Down/genética , Pacientes , Polimorfismo de Nucleotídeo Único , Proteína Proto-Oncogênica c-ets-2/genética , Algoritmos , Povo Asiático/genética , Sequência de Bases , Estudos de Casos e Controles , Criança , Estudos de Coortes , Biologia Computacional , Síndrome de Down/complicações , Feminino , Frequência do Gene , Humanos , Índia , Leucemia/etiologia , Leucemia/genética , Desequilíbrio de Ligação , Masculino , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único/fisiologia , Proteína Proto-Oncogênica c-ets-2/química , População Branca/genéticaRESUMO
PURPOSE: Most aggressive thyroid cancers are commonly associated with a BRAF V600E mutation. Preclinical and clinical data in BRAF V600E cancers suggest that combined BRAF and MEK inhibitor treatment results in a response, but resistance is common. One mechanism of acquired resistance is through persistent activation of tyrosine kinase (TK) signaling by alternate pathways. We hypothesized that combination therapy with BRAF and multitargeting TK inhibitors (MTKI) might be more effective in BRAF V600E thyroid cancer than in single-agent or BRAF and MEK inhibitors. EXPERIMENTAL DESIGN: The combined drug activity was analyzed to predict any synergistic effect using high-throughput screening (HTS) of active drugs. We performed follow-up in vitro and in vivo studies to validate and determine the mechanism of action of synergistic drugs. RESULTS: The MTKI ponatinib and the BRAF inhibitor PLX4720 showed synergistic activity by HTS. This combination significantly inhibited proliferation, colony formation, invasion, and migration in BRAF V600E thyroid cancer cell lines and downregulated pERK/MEK and c-JUN signaling pathways, and increased apoptosis. PLX4720-resistant BRAF V600E cells became sensitized to the combination treatment, with decreased proliferation at lower PLX4720 concentrations. In an orthotopic thyroid cancer mouse model, combination therapy significantly reduced tumor growth (P < 0.05), decreased the number of metastases (P < 0.05), and increased survival (P < 0.05) compared with monotherapy and vehicle control. CONCLUSIONS: Combination treatment with ponatinib and PLX4720 exhibited significant synergistic anticancer activity in preclinical models of BRAF V600E thyroid cancer, in addition to overcoming PLX4720 resistance. Our results suggest this combination should be tested in clinical trials.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Sinergismo Farmacológico , Mutação , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Neoplasias da Glândula Tireoide/tratamento farmacológico , Animais , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Ensaios de Triagem em Larga Escala/métodos , Humanos , Imidazóis/administração & dosagem , Indóis/administração & dosagem , Camundongos , Camundongos Endogâmicos NOD , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Piridazinas/administração & dosagem , Sulfonamidas/administração & dosagem , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/patologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
We evaluated DNA binding of the B-HLH family members TCF4 and USF1 using protein binding microarrays (PBMs) containing double-stranded DNA probes with cytosine on both strands or 5-methylcytosine (5mC) or 5-hydroxymethylcytosine (5hmC) on one DNA strand and cytosine on the second strand. TCF4 preferentially bound the E-box motif (CAN|NTG) with strongest binding to the 8-mer CAG|GTGGT. 5mC uniformly decreases DNA binding of both TCF4 and USF1. The bulkier 5hmC also inhibited USF1 binding to DNA. In contrast, 5hmC dramatically enhanced TCF4 binding to E-box motifs ACAT|GTG and ACAC|GTG, being better bound than any 8-mer containing cytosine. Examination of X-ray structures of the closely related TCF3 and USF1 bound to DNA suggests TCF3 can undergo a conformational shift to preferentially bind to 5hmC while the USF1 basic region is bulkier and rigid precluding a conformation shift to bind 5hmC. These results greatly expand the regulatory DNA sequence landscape bound by TCF4.
Assuntos
5-Metilcitosina/análogos & derivados , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/química , DNA/química , Elementos E-Box , Análise Serial de Proteínas/métodos , Fator de Transcrição 4/química , 5-Metilcitosina/química , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/ultraestrutura , Sítios de Ligação , DNA/ultraestrutura , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/ultraestrutura , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Mapeamento de Interação de Proteínas , Fator de Transcrição 4/ultraestruturaRESUMO
BACKGROUND: The aim of this study is to evaluate the expression of human telomerase reverse transcription (hTERT) enzyme in chronic periodontitis (CP) and aggressive periodontitis (AgP) compared with healthy individuals. METHODS: A total of 79 individuals consented to participate in the study. The study sample comprised healthy individuals (n = 30), patients with CP (n = 30), and patients with AgP (n = 19). Gingival tissue was collected and evaluated for hTERT expression by Western blot and immunohistochemical methods. Reverse transcription polymerase chain reaction was performed using the gingival crevicular fluid (GCF) samples. RESULTS: The hTERT messenger RNA (mRNA) and protein expression was significantly higher in AgP compared with CP (P <0.001). In GCF, 53.33% of patients with CP and 68.42% of patients with AgP were showing hTERT mRNA expression, but it was not detected in the control group. The AgP tissue showed higher hTERT expression compared with CP (P <0.001). The hTERT mRNA expression did not show a correlation with gingival index (GI), plaque index (PI), probing depth (PD), and clinical attachment loss (AL) in patients with AgP, whereas hTERT protein expression was strongly correlated with GI, PI, PD, and AL in patients with AgP. The protein expression of hTERT shows significant but moderate correlation with GI and AL in patients with CP. CONCLUSION: High expression of hTERT might be associated with periodontal disease progression, suggesting that hTERT could be a potential prognostic marker.
Assuntos
Periodontite Agressiva/enzimologia , Periodontite Crônica/enzimologia , Telomerase/análise , Adulto , Biomarcadores/análise , Tecido Conjuntivo/enzimologia , Índice de Placa Dentária , Epitélio/enzimologia , Feminino , Gengiva/enzimologia , Líquido do Sulco Gengival/enzimologia , Humanos , Masculino , Pessoa de Meia-Idade , Perda da Inserção Periodontal/classificação , Perda da Inserção Periodontal/enzimologia , Índice Periodontal , Bolsa Periodontal/classificação , Bolsa Periodontal/enzimologia , RNA Mensageiro/análise , Adulto JovemRESUMO
BACKGROUND: Arsenic, acting as an endocrine disruptor, causes reproductive malfunctions. Studies have been undertaken to find out whether the co-supplementation of α-tocopherol and ascorbic acid (AT-AA) could reduce the arsenic-induced testicular toxicity caused by oxidative stress and resulting DNA damage. METHODS: Adult male Wistar rats (120±10 g) were given arsenic trioxide [3 mg/kg body weight (b.wt.) per day] for 30 consecutive days and the supplement group received α-tocopherol (400 mg/kg b.wt. per day) and ascorbic acid (200 mg/kg b.wt. per day). Reproductive functions were evaluated with respect to the histoarchitecture, gametokinetic activity, androgenic potential, glutathione-dependent antioxidant status and DNA damage of the testis. RESULTS: Arsenic treatment caused marked reduction in the relative weight of the testis (p<0.05) but showed no effect on body weight. The number of germ cells at stage VII of the spermatogenic cycle (p<0.01), the seminiferous tubular diameter (p<0.001) and Leydig cell nuclear area (p<0.01) were significantly reduced. Notable decrease in the activities of testicular Δ5, 3ß-HSD (p<0.05) and 17ß-HSD (p<0.01) with a concomitant fall in serum testosterone level (p<0.01) along with significant diminution in testicular glutathione S-transferase (p<0.05) activity and reduced glutathione level (p<0.01) were observed. Significant DNA damage (p<0.001) in spermatogenic cells was also noted. All these alterations including DNA strand breakage were seen to be protected with the coadministration of AT-AA. CONCLUSIONS: The data suggest that the protection of testicular toxicity in arsenic-exposed adult rats is possible with combined coadministration of AT-AA.
Assuntos
Antioxidantes/farmacologia , Ácido Ascórbico/farmacologia , Disruptores Endócrinos/toxicidade , Óxidos/toxicidade , Testículo/efeitos dos fármacos , alfa-Tocoferol/farmacologia , Animais , Antioxidantes/administração & dosagem , Antioxidantes/uso terapêutico , Trióxido de Arsênio , Arsenicais , Ácido Ascórbico/administração & dosagem , Ácido Ascórbico/uso terapêutico , Dano ao DNA , Sinergismo Farmacológico , Quimioterapia Combinada , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Espermatogênese/efeitos dos fármacos , Testículo/enzimologia , Testículo/metabolismo , Testículo/patologia , Testosterona/sangue , alfa-Tocoferol/administração & dosagem , alfa-Tocoferol/uso terapêuticoRESUMO
CONTEXT: With an increase in the abuse of various oral habitual products in India over the past few decades; the incidence of oral potentially malignant conditions as leukoplakia, oral submucous fibrosis and squamous cell carcinoma (SCC) rates have also increased. No recent study has been conducted reporting the scenario of oral cancer and potentially malignant conditions in Eastern India (specifically Kolkata). AIMS: The present study was conducted at Dr. R. Ahmed Dental College, Kolkata during 2010-2011 to find a possible correlation between the effects of the different oral habits, age, sex and the different types of oral mucosal lesions among patients reported to the hospital. This study also enabled us to see the predilection of the various histopathological stages of the lesions for different sites of the oral cavity. SUBJECTS AND METHODS: The study group consisted of 698 patients having either oral potentially malignant or malignant lesion. The control group consisted of 948 patients who had reported to the hospital for different oral/dental problems and had the habit of tobacco, areca nut and/or alcohol usage for at least 1 year. STATISTICAL ANALYSIS: The unadjusted odds ratio, the 95% confidence interval, and the P value were calculated to correlate patients with/without different kinds of habit and having/not having various kinds of oral lesions. RESULTS: Our study shows that for males having the habit of taking smokeless tobacco or mixed habit poses the highest risk for developing SCC. For females, significant risk of developing SCC was found in patients habituated to processed areca nut chewing. CONCLUSION: This study presents probably for the first time in recent years the occurrence of oral potentially malignant and malignant conditions amongst patients having deleterious habits in a hospital based population of Kolkata.
RESUMO
Chewing betel quid may release chemical carcinogens including xenobiotics resulting in oral malignancy cases preceded by potential malignant lesions and conditions - Oral Submucous Fibrosis (OSF) being one of them. The cytochrome P4501A1 (CYP1A1) enzyme is central to the metabolic activation of these xenobiotics, whereas CYP2E1 metabolizes the nitrosamines and tannins. The present study investigated the association of polymorphisms at CYP1A1m1 (T3801C), m2 (A2455G), and CYP2E1 PstI site (nucleotide 21259) with the risk of OSF. The study was conducted on 75 OSF patients and 150 controls from an eastern Indian population. The above polymorphisms were analyzed by PCR-RFLP method. Analyses of data show that polymorphisms in CYP1A1m2 [OR=8.25 (4.31-15.80)]; CYP1A1m1 [OR=2.88 (1.57-5.24)] and CYP2E1 PstI site [OR=3.16 (1.10-9.04)] revealed significant association with OSF. Our results suggest that polymorphism in CYP1A1 and CYP2E1 may confer an increased risk for Oral Submucous Fibrosis.
Assuntos
Areca/efeitos adversos , Citocromo P-450 CYP1A1/genética , Sistema Enzimático do Citocromo P-450/genética , Fibrose Oral Submucosa/genética , Polimorfismo Genético , Adulto , Estudos de Casos e Controles , Família 2 do Citocromo P450 , Desoxirribonucleases de Sítio Específico do Tipo II/genética , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Feminino , Predisposição Genética para Doença , Humanos , Índia , Masculino , Mastigação , Pessoa de Meia-IdadeRESUMO
CONTEXT: Chewing of processed arecanut products with tobacco and betel quid has been attributed to many oral pathological conditions. These products are very popular among the youngsters of lower economic groups. Genetic predisposition has been now identified as a major risk factor for increasing the susceptibility toward the disease among these chewers. AIMS: Our study mainly aims to find out the predisposition of LOX (G473A) and NQO1 (C609T) polymorphisms and present a comparison between the population (habitually exposed to processed arecanut and smokeless tobacco products) of a metro-city Kolkata and the tea-garden workers of Darjeeling district of West Bengal. SETTINGS AND DESIGN: Subjects for the study was recruited from various oral health check-up camps organized in the tea-gardens of Darjeeling district and Kolkata city. MATERIALS AND METHODS: Genotyping analysis was done through a Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP)-based approach. STATISTICAL ANALYSIS USED: A two-way contingency table analysis software (JAVASTAT: http://statpages.org/ctab2 × 2.html) using 95% confidence interval was used to study the distribution of genotypes among the populations. A P < 0.05 was considered to be significant. RESULTS: The results indicates both the heterozygous and homozygous carriers of NQO1 C > T (609) was found to be significantly higher among the north Bengal tea-garden workers [OR 0.480 (0.280-0.82) P = 0.01; 0.218 (0.091-0.524) P = 0.0001], respectively. Interestingly CT (21% in both) and TT (8% and 7%, respectively) were found to be equally distributed in the two populations. For LOX G > A (473) a significantly higher number of Kolkata individuals were found to carry the heterozygous GA allele in individuals aged <30 years [OR 3.779 (1.684-6.547) P = 0.001]. However, none were carrier of heterozygous GA allele of Kolkata population as compared with 29% north Bengal tea-garden workers aged above 31 years. CONCLUSIONS: A close observation of occurrence of oral diseases over time among such a population will be helpful to identify risk genotypes responsible for betel quid-induced oral diseases.
RESUMO
Vibrio cholerae, the etiological agent of cholera, colonizes the small intestine, produces an enterotoxin and causes acute inflammatory response at intestinal epithelial cell surface. Pretreatment of intestinal epithelial cells with quercetin reduces the level of V. cholerae induced IL-8 in dose and time dependent manner as determined by ELISA and RT-PCR. Immunofluorescence studies showed that quercetin suppresses the translocation of p50 subunit of NF-κB. In vivo, quercetin administration produced a significant reduction of neutrophil infiltration in the intestinal epithelial layer of suckling mouse. Taken together, quercetin could inhibit the V. cholerae induced inflammation and may therefore find use in management of V. cholerae induced pathogenesis.
Assuntos
Anti-Inflamatórios/metabolismo , Células Epiteliais/imunologia , Células Epiteliais/microbiologia , Interleucina-8/biossíntese , NF-kappa B/metabolismo , Quercetina/metabolismo , Vibrio cholerae/imunologia , Animais , Animais Lactentes , Anti-Inflamatórios/administração & dosagem , Ensaio de Imunoadsorção Enzimática , Células Epiteliais/efeitos dos fármacos , Intestino Delgado/imunologia , Intestino Delgado/patologia , Leucócitos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Microscopia de Fluorescência , Reação em Cadeia da Polimerase em Tempo RealRESUMO
This study was conducted as part of an epidemiological survey of 126 nonsmokers and 178 smokers, showing primary infertility residing around Kolkata region of Eastern India. Their lifestyle history including smoking habits along with semen and blood were collected. The study examined the association of cigarette smoking with the risk of infertility, by determining the semen quality, follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone levels, and androgen receptor (AR)-CAG repeat length in a group of smokers compared with a control group (non smokers). Based on conventional WHO criteria, lower sperm motility (P < 0.001) and increased sperm morphological defects (P < 0.0001) were associated with smoking habits. Binary logistic regression analysis for the effect of smoking status on sperm DNA integrity demonstrated significant positive correlation (p = 0.006). Serum FSH and LH levels were higher for smokers compared with non-smokers while the testosterone level decreased significantly with the increasing smoking habit. The mean length of CAG repeats in AR gene was significantly higher for smokers with low testosterone compared to non-smokers. The study suggested that smoking is associated with altered semen quality, endocrine hormonal status, and number of CAG repeats in the AR gene.