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Cell signaling relies extensively on dynamic pools of redox-inactive metal ions such as sodium, potassium, calcium and zinc, but their redox-active transition metal counterparts such as copper and iron have been studied primarily as static enzyme cofactors. Here we report that copper is an endogenous regulator of lipolysis, the breakdown of fat, which is an essential process in maintaining body weight and energy stores. Using a mouse model of genetic copper misregulation, in combination with pharmacological alterations in copper status and imaging studies in a 3T3-L1 white adipocyte model, we found that copper regulates lipolysis at the level of the second messenger, cyclic AMP (cAMP), by altering the activity of the cAMP-degrading phosphodiesterase PDE3B. Biochemical studies of the copper-PDE3B interaction establish copper-dependent inhibition of enzyme activity and identify a key conserved cysteine residue in a PDE3-specific loop that is essential for the observed copper-dependent lipolytic phenotype.
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Cobre/farmacología , AMP Cíclico/metabolismo , Lipólisis/efectos de los fármacos , Inhibidores de Fosfodiesterasa 3/farmacología , Células 3T3-L1 , Animales , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 3/química , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 3/metabolismo , Relación Dosis-Respuesta a Droga , Ratones , Estructura Molecular , Relación Estructura-ActividadRESUMEN
In this study, we have analyzed six genetic polymorphisms of the VEGF-A gene and correlated the genetic data with plasma and tissue expression of VEGF-A in epithelial ovarian carcinomas. A total of 130 cases including 95 malignant carcinomas, 17 low malignant potential and 18 benign tumours were studied. rs699947, rs833061, rs1570360, rs2010963, rs1413711 and rs3025039 were studied by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Plasma levels of VEGF-A were estimated by enzyme-linked immunosorbent assay (ELISA) and tissue expression of VEGF-A by immunohistochemistry (IHC). Four polymorphisms of the above excluding rs699947 and rs3025039 showed significant association with malignancy, and we observed the presence of positive correlation between haplotype CCGGCC and increased expression of VEGF-A in both plasma and tissues which also correlated with poor prognosis and recurrence suggesting a probable increase in resistance to treatment in such carriers. Highly upregulated tissue expression of VEGF-A was seen in all epithelial ovarian carcinomas with intensity of expression increasing from benign to malignant cases. ELISA data from our study showed an increase in circulating levels of VEGF-A in malignancies. VEGF-A plasma levels can be employed as a biomarker for high-grade malignancy in epithelial ovarian cancers alongside tissue expression and CA-125 levels. This study is unique due to the fact that a simultaneous analysis of plasma and tissue expression has been demonstrated and is a first such study in epithelial ovarian cancers and representing the Indian population (South-east Asian) synchronized with genetic polymorphism data as well.
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Expresión Génica , Neoplasias Glandulares y Epiteliales/genética , Neoplasias Glandulares y Epiteliales/metabolismo , Neoplasias Ováricas/genética , Neoplasias Ováricas/metabolismo , Polimorfismo de Nucleótido Simple , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Alelos , Carcinoma Epitelial de Ovario , Estudios de Casos y Controles , Femenino , Genotipo , Haplotipos , Humanos , Inmunohistoquímica , Neoplasias Glandulares y Epiteliales/sangre , Neoplasias Glandulares y Epiteliales/patología , Oportunidad Relativa , Neoplasias Ováricas/sangre , Neoplasias Ováricas/patología , Factor A de Crecimiento Endotelial Vascular/sangreRESUMEN
The role of defective mismatch repair (MMR) system in ovarian carcinoma is not well defined. The purpose of the study was to determine the relationship between microsatellite instability (MSI), promoter methylation and protein expression of MMR genes in epithelial ovarian carcinoma (EOC). MSI and promoter methylation of MLH1, MSH2 and PMS2 genes were studied using PCR methods in the study cohort. A small subset of samples was used to analyze the protein expression by immunohistochemistry (IHC). MSI was observed in >60% of tumor samples and 47% of normal ovaries. MLH1 was methylated in 37.5% and 64.3% EOCs and LMP tumors. The loss of immunoexpression of MMR genes was not seen in ovarian tumors. There was no correlation between MSI, promoter methylation and protein expression of the MMR genes suggesting that each may function independently. MSI is a common event in ovarian carcinoma and may increase the clinical awareness of the subset of tumors.
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Carcinoma/genética , Metilación de ADN , Reparación de la Incompatibilidad de ADN , Enzimas Reparadoras del ADN/genética , Inestabilidad Genómica , Repeticiones de Microsatélite , Neoplasias Ováricas/genética , Proteínas Adaptadoras Transductoras de Señales/genética , Adenosina Trifosfatasas/genética , Enzimas Reparadoras del ADN/metabolismo , Proteínas de Unión al ADN/genética , Femenino , Humanos , Endonucleasa PMS2 de Reparación del Emparejamiento Incorrecto , Homólogo 1 de la Proteína MutL , Proteína 2 Homóloga a MutS/genética , Proteínas Nucleares/genética , Regiones Promotoras GenéticasRESUMEN
Mounting evidences suggest that aberrant methylation of CpG islands is a major pathway leading to the inactivation of tumour suppressor genes and the development of cancer. The aim of the current study was to examine the prevalence of the promoter hypermethylation and protein expression of the BRCA1 gene in epithelial ovarian carcinoma (EOC) to understand the role of epigenetic silencing in ovarian carcinogenesis. We studied the promoter methylation of the BRCA1 gene by methylation-specific PCR in a cohort of 88 patients with EOC, 14 low malignant potential (LMP) tumours and 20 patients with benign tumours of the ovary. The expression of the BRCA1 protein by immunohistochemical analysis was carried out in a subset of 64 EOCs, 10 LMP tumours, 10 benign tumours and 5 normal ovarian tissues. The frequencies of methylation in EOCs and LMP tumours were 51.2 and 57%, respectively, significantly higher (p = 0.000 and p = 0.001) in comparison to benign tumours and normal ovarian tissue where no methylation was seen. Expression of BRCA1 was significantly lower in EOCs (p = 0.003). Lack of protein expression correlated with tumour grade and type. The methylation status correlated well with downregulation of BRCA1 expression. Our results clearly demonstrate that hypermethylation of BRCA1 promoter is a frequent event in ovarian cancer. These data support the hypothesis that BRCA1 promoter methylation plays an important role in the functional inactivation of BRCA1. Follow-up clinical data will reveal the impact of BRCA1 methylation on survival.
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Proteína BRCA1/análisis , Metilación de ADN , Genes BRCA1 , Neoplasias Glandulares y Epiteliales/genética , Neoplasias Ováricas/genética , Regiones Promotoras Genéticas , Adulto , Anciano , Carcinoma Epitelial de Ovario , Estudios de Cohortes , Femenino , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Neoplasias Glandulares y Epiteliales/química , Neoplasias Glandulares y Epiteliales/patología , Neoplasias Ováricas/química , Neoplasias Ováricas/patología , Análisis de Matrices TisularesRESUMEN
Silencing of tumor suppressor and tumor-related genes by promoter hypermethylation is one of the major events in ovarian carcinogenesis. In this study, we analyzed aberrant promoter methylation of p16 and RAR-ß genes in 134 epithelial ovarian carcinomas (EOCs), 23 low malignant potential (LMP) tumors, 26 benign cystadenomas, and 15 normal ovarian tissues. Methylation was investigated by methylation-specific PCR (MSP), and the results were confirmed by bisulfite DNA sequencing. Relative gene expression of p16 and RAR-ß was done using quantitative reverse transcriptase PCR (qRT-PCR) on 51 EOC cases, 9 LMP tumors, and 7 benign cystadenomas with 5 normal ovarian tissues. Aberrant methylation for p16 and RAR-ß was present in 43 % (58/134) and 31 % (41/134) in carcinoma cases, 22 % (05/23) and 52 % (12/23) in LMP tumors, and 42 % (11/26) and 69 % (18/26) in benign cystadenomas. No methylation was observed in any of the normal ovarian tissues. The mRNA expression level of p16 and RAR-ß was significantly downregulated in EOC and LMP tumors than the corresponding normal tissues whereas the expression level was normal in benign cystadenomas for p16 and slightly reduced for RAR-ß. A significant correlation of p16 promoter methylation was observed with reduced gene expression in EOC. For RAR-ß, no significant correlation was observed between promoter methylation and gene expression. Our results suggest that epigenetic alterations of p16 and RAR-ß have an important role in ovarian carcinogenesis and that mechanism along with methylation plays a significant role in downregulation of RAR-ß gene in ovarian cancer.
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Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Epigénesis Genética , Neoplasias Glandulares y Epiteliales/genética , Neoplasias Ováricas/genética , Receptores de Ácido Retinoico/genética , Adulto , Anciano , Secuencia de Bases , Metilación de ADN , Regulación hacia Abajo , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Persona de Mediana Edad , Datos de Secuencia Molecular , Neoplasias Glandulares y Epiteliales/patología , Neoplasias Ováricas/patología , Regiones Promotoras Genéticas/genética , Modelos de Riesgos Proporcionales , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/estadística & datos numéricos , Análisis de Supervivencia , Adulto JovenRESUMEN
BACKGROUND & OBJECTIVES: Epigenetic alterations, in addition to multiple gene abnormalities, are involved in the genesis and progression of human cancers. Aberrant methylation of CpG islands within promoter regions is associated with transcriptional inactivation of various tumour suppressor genes. O 6-methyguanine-DNA methyltransferase (MGMT) is a DNA repair gene that removes mutagenic and cytotoxic adducts from the O 6 -position of guanine induced by alkylating agents. MGMT promoter hypermethylation and reduced expression has been found in some primary human carcinomas. We studied DNA methylation of CpG islands of the MGMT gene and its relation with MGMT protein expression in human epithelial ovarian carcinoma. METHODS: A total of 88 epithelial ovarian cancer (EOC) tissue samples, 14 low malignant potential (LMP) tumours and 20 benign ovarian tissue samples were analysed for MGMT promoter methylation by nested methylation-specific polymerase chain reaction (MSP) after bisulphite modification of DNA. A subset of 64 EOC samples, 10 LMP and benign tumours and five normal ovarian tissue samples were analysed for protein expression by immunohistochemistry. RESULTS: The methylation frequencies of the MGMT gene promoter were found to be 29.5, 28.6 and 20 per cent for EOC samples, LMP tumours and benign cases, respectively. Positive protein expression was observed in 93.8 per cent of EOC and 100 per cent in LMP, benign tumours and normal ovarian tissue samples. Promoter hypermethylation with loss of protein expression was seen only in one case of EOC. INTERPRETATION & CONCLUSIONS: Our results suggest that MGMT promoter hypermethylation does not always reflect gene expression.
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Metilación de ADN/genética , Metilasas de Modificación del ADN/biosíntesis , Enzimas Reparadoras del ADN/biosíntesis , Proteínas de Neoplasias/biosíntesis , Neoplasias Ováricas/genética , Proteínas Supresoras de Tumor/biosíntesis , Adulto , Anciano , Metilasas de Modificación del ADN/genética , Enzimas Reparadoras del ADN/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Persona de Mediana Edad , Proteínas de Neoplasias/genética , Neoplasias Ováricas/patología , Regiones Promotoras Genéticas , Proteínas Supresoras de Tumor/genéticaRESUMEN
Vascular endothelial growth factor (VEGF) plays an important role in the development of Breast Cancer. The aim of this study was to investigate the association of polymorphisms in the VEGF gene on prognosis of Breast Cancer patients. This study comprised 200 patients with histologically confirmed cases of Breast cancer and 200 controls. Genotyping of the VEGF gene polymorphisms at +405G>C,-1154G>A, were performed by PCR-RFLP analysis. Preoperative plasma VEGF levels were determined by ELISA. Amongst both cases and controls, the genotypic distribution of the individual SNPs were all in Hardy-Weinberg equilibrium. Mean VEGF level was significantly elevated in cases compared to controls (t = 8.248; P < 0.001). No significant association was found between +405G>C,-1154G>A VEGF polymorphism and Breast Cancer. Logistic regression analysis revealed that 405GG & 1154GG were associated with higher levels of VEGF.
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PURPOSE: Our explorative study assessed a panel of molecules for their association with epithelial ovarian carcinomas and their prognostic implications. The panel included tissue expression of VEGF-C, COX-2, Ki-67 and eNOS alongside plasma levels of VEGF-C and nitric oxide. METHODS: 130 cases were enrolled in the study. Plasma levels were quantified by ELISA and tissue expressions were scored by immunohistochemistry. The Chi square and Fischer's exact test were applied to examine the impact of markers on clinicopathological factors. Non-parametric Spearman's rank correlation test was applied to define the association among test factors. RESULTS: Plasma VEGF-C levels and COX-2 tissue expression strongly predicted recurrence and poor prognosis (< 0.001). Tissue Ki-67 was strongly indicative of late-stage disease (< 0.001). The aforementioned markers significantly associated with clinicopathological factors. Nuclear staining of VEGF-C was intriguing and was observed to correlate with high grade-stage malignancies, highly elevated plasma VEGF-C, and with recurrence. eNOS tissue expression showed no significant impact while nitric oxide associated positively with ascites levels. Tissue expression of VEGF-C did not associate significantly with poor prognosis although the expression was highly upregulated in most of the cases. CONCLUSION: Plasma VEGF-C holds immense promise as a prognostic marker and the nuclear staining of VEGF-C seems to have some significant implication in molecular carcinogenesis and is a novel finding that commands further robust scrutiny. We present a first such study that assesses a set of biomarkers for prognostic implications in clinical management of epithelial ovarian carcinomas in a pan-Indian (Asian) population.
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Neoplasias Ováricas , Humanos , Femenino , Carcinoma Epitelial de Ovario/patología , Pronóstico , Neoplasias Ováricas/patología , Ciclooxigenasa 2/metabolismo , Factor C de Crecimiento Endotelial Vascular , Antígeno Ki-67 , Óxido Nítrico , Estadificación de Neoplasias , Biomarcadores de Tumor/metabolismoRESUMEN
In the realm of environmental challenges, microplastics have emerged as a pressing threat, presenting risks to both individuals and ecosystems. Conventional treatment plants are presently not equipped for effectively removing these minute contaminants. This study presents an investigation into the potential of a continuous flow biochar column, utilizing biochar derived from banana peel through a nitrogen-free slow pyrolysis process for the removal of microplastics. A systematic exploration of various parameters, including bed height, flow rate, inflow microplastic concentration, and microplastic size is undertaken to discern their impact on polystyrene removal efficiency. A peak removal efficiency of 92.16% has been achieved under specific conditions: a 6-cm bed height, a 3-mL/min flow rate, an inlet concentration of 0.05 g/L, and microplastic sizes ranging from 150 to 300 µm. The removal efficiency was inversely affected by flow rate while directly influenced by bed height. To deepen the understanding of polystyrene removal on biochar, a detailed characterization of the synthesized material was carried out. The removal of microplastics by banana peel biochar (BPB) is observed to be dominated by adsorption and filtration processes. The entanglement of microplastics with minuscule biochar granules, capture between particles, and entrapment in the porous system were identified as the mechanisms of removal. Leveraging the hydrophobic nature of polystyrene microplastics, interactions with the hydrophobic functional groups in BPB result in effective adsorption. This is further complemented by self-agglomeration and filtration mechanisms that synergistically contribute to the elimination of larger agglomerates. The findings thus provide a comprehensive understanding, offering hope for a more effective strategy in mitigating the environmental impact of microplastics.
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Microplásticos , Contaminantes Químicos del Agua , Humanos , Poliestirenos , Plásticos , Ecosistema , Contaminantes Químicos del Agua/análisis , Carbón Orgánico/química , AdsorciónAsunto(s)
Exosomas/enzimología , NADPH Oxidasa 2/metabolismo , Estrés Oxidativo , Animales , Axones/enzimología , Axones/metabolismo , Exosomas/metabolismo , Humanos , Peróxido de Hidrógeno/metabolismo , Enfermedades Neurodegenerativas/enzimología , Enfermedades Neurodegenerativas/metabolismo , Oxidación-Reducción , Especies Reactivas de Oxígeno/metabolismo , Transducción de SeñalRESUMEN
The aim of the study was to evaluate the immunoexpression of E-cadherin, ß-catenin, and Ki-67, as well as the promoter methylation of E-cadherin gene in epithelial ovarian cancer (EOC), as well as to find a possible relationship between the immunoexpression and hypermethylation. Promoter methylation was studied using methylation-specific PCR in 86 malignant cases, 14 low malignant potential (LMP) tumors and 19 benign cystadenomas. Immunohistochemical expression was carried out in 64 malignant cases, 8 LMP tumors, and 11 benign cystadenomas. Immunoexpression of E-cadherin was reduced in EOC, while 100 % expression was seen in LMP tumors and benign cystadenomas. An interesting observation was the nuclear expression of E-cadherin in a high percentage of cancers, which showed a positive correlation with Ki-67. Β-Catenin expression showed heterogeneous localization with increased nuclear localization, which was significantly higher in cases that did not express E-cadherin. Promoter methylation of E-cadherin was 36, 14, and 11 % in EOC, LMP tumors, and benign cystadenomas, respectively. Our results suggest that reduced expression of E-cadherin is associated with promoter methylation of E-cadherin gene, in addition to providing evidence for the aberrant nuclear localization of E-cadherin in EOC.
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Cadherinas/genética , Cadherinas/metabolismo , Antígeno Ki-67/metabolismo , Neoplasias Glandulares y Epiteliales/metabolismo , Neoplasias Ováricas/metabolismo , Regiones Promotoras Genéticas , beta Catenina/metabolismo , Cadherinas/biosíntesis , Carcinoma Epitelial de Ovario , Núcleo Celular/metabolismo , Metilación de ADN , Femenino , Humanos , Antígeno Ki-67/biosíntesis , Neoplasias Glandulares y Epiteliales/genética , Neoplasias Ováricas/genética , beta Catenina/biosíntesis , beta Catenina/genéticaRESUMEN
The human epidermal receptor-2/neu (HER-2/neu) oncogene encodes a transmembrane tyrosine kinase receptor. This molecule could have a diagnostic value since the extracellular domain of c-erbB-2 (HER-2) transmembrane is shed into the blood as a circulating antigen. The diagnostic value of serum HER-2/neu was calculated along with the conventional marker carbohydrate antigen 15-3 (CA15-3) and carcinoembryonic antigen (CEA) at 85th percentiles. Serum levels of breast carcinoma antigens HER-2/neu, CEA and CA15-3 were determined in 175 normal individuals and 268 malignant patients. The soluble form of serum HER-2/neu, CEA and CA15-3 was assayed by enzyme linked immunosorbent assay in control and breast cancer patients prior to treatment. Serum levels of the tested tumor markers HER-2/neu and CA15-3 and CEA were significantly higher in cancer patients compared to controls. At 85th percentile the sensitivity of HER-2/neu was 51.12 %; the specificity was 86.29 % and the overall accuracy was 64.56 %. The sensitivity of CA15-3 was 73.13 %; the specificity was 85.14 % and the overall accuracy was 77.88 %. The sensitivity of the combined testing was 82.84 %; the specificity was 73.71 % and the overall accuracy was 80.01 %. The sensitivity and the overall accuracy of combined testing were higher than those of HER-2/neu and CA15-3 testing single. The combined testing of HER-2/neu and CA15-3 can increase the sensitivity and overall accuracy of breast cancer diagnosis. The results of this study suggest that the use of multiple tumor markers may be employed as combination and at 85th percentiles to assess the prognosis.
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HIV-1 is a master at deceiving the immune system and usurping host biosynthetic machinery. Although HIV-1 is coated with host-derived glycoproteins, only glycosylation of viral gp120 has been described. Here we use lectin microarray technology to analyze the glycome of intact HIV-1 virions. We show that the glycan coat of human T cell line-derived HIV-1 matches that of native immunomodulatory microvesicles. The carbohydrate composition of both virus and microvesicles is cell-line dependent, which suggests a mechanism to rapidly camouflage the virus within the host. In addition, binding of both virus and microvesicles to antiviral lectins is enriched over the host cell, raising concern about targeting these glycans for therapeutics. This work also sheds light on the binding of HIV-1 to galectin-1, an important human immune lectin. Overall, our work strongly supports the theory that HIV-1 co-opts the exocytic pathway of microvesicles, thus potentially explaining why eliciting a protective antiviral immune response is difficult.
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Carbohidratos/genética , VIH-1/metabolismo , Lectinas/metabolismo , Linfocitos T/metabolismo , Carbohidratos/fisiología , Línea Celular , Biología Computacional , Galectina 1/metabolismo , Perfilación de la Expresión Génica , Glicómica , VIH-1/genética , Humanos , Lectinas/genética , Manosa/metabolismo , Análisis por MicromatricesRESUMEN
BACKGROUND & OBJECTIVES: An association between over-expression of proto-oncogene Her-2/neu and resistance to tamoxifen in estrogen receptor (ER) positive, primary and metastatic breast cancer has been suggested. HR+/Her-2/neu+ patients have a poor response to endocrine therapy, making this group a matter of debate. The present study was carried out to examine whether Her-2/neu expression in breast cancer patients predicted tamoxifen effectiveness. METHODS: An enzyme-linked immunosorbent assay (ELISA) specific for the extracellular domain of the Her-2/neu oncoprotein product was used to detect serum Her-2/neu levels in 207 patients with histological confirmed breast cancer. Tissue Her-2 /neu expression was studied in 100 breast cancer patients by immunohistochemistry (IHC) and compared with serum Her-2/neu levels by ELISA. RESULTS: Among 207 histologically confirmed breast cancer patients, 53 were serum Her-2/neu positive. Patients who were treated with surgery, chemotherapy, and radiotherapy showed significantly (P<0.05) reduced serum Her-2/neu levels, showing good response to treatment. Patients who were treated with tamoxifen in addition to the above regimen did not show any significant reduction in serum Her-2/neu levels showing resistance to treatment. INTERPRETATION & CONCLUSIONS: The present findings study support the hypothesis that Her-2/neu overexpression contributes to tamoxifen resistance. Trastuzumab or other growth factor inhibitors should be used in combination with tamoxifen, since monotherapy is not likely to be optimal in HR+/Her-2/neu+ tumours.
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Neoplasias de la Mama/genética , Neoplasias de la Mama/terapia , Resistencia a Antineoplásicos , Antagonistas de Estrógenos/uso terapéutico , Receptor ErbB-2/genética , Tamoxifeno/uso terapéutico , Adulto , Neoplasias de la Mama/patología , Quimioterapia Adyuvante , Terapia Combinada , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Persona de Mediana Edad , Estudios Prospectivos , Proto-Oncogenes Mas , Receptor ErbB-2/sangre , Resultado del TratamientoRESUMEN
BACKGROUND & OBJECTIVES: Methylenetetrahydrofolate reductase (MTHFR) is a critical enzyme in folate metabolism and involved in DNA synthesis, DNA repair and DNA methylation. The two common functional polymorphisms of MTHFR, 677 C-->T and 1298 A-->C have shown to impact several diseases including cancer. This case-control study was undertaken to analyse the association of the MTHFR gene polymorphisms 677 C-->T and 1298 A-->C and risk of colorectal cancer (CRC). METHODS: One hundred patients with a confirmed histopathologic diagnosis of CRC and 86 age and gender matched controls with no history of cancer were taken for this study. DNA was isolated from peripheral blood samples and the genotypes were determined by PCR-RFLP. The risk association was estimated by compounding odds ratio (OR) with 95 per cent confidence interval (CI). RESULTS: Genotype frequency of MTHFR 677 CC, CT and TT were 76.7, 22.1 and 1.16 per cent in controls, and 74, 25 and 1.0 per cent among patients. The 'T' allele frequency was 12.21 and 13.5 per cent in controls and patients respectively. The genotype frequency of MTHFR 1298 AA, AC, and CC were 25.6, 58.1 and 16.3 per cent for controls and 22, 70 and 8 per cent for patents respectively. The 'C' allele frequency for 1298 A-->C was 43.0 and 45.3 per cent respectively for controls and patients. The OR for 677 CT was 1.18 (95% CI 0.59-2.32, P = 0.642), OR for 1298 AC was 1.68 (95% CI 0.92-3.08, P = 0.092) and OR for 1298 CC was 0.45 (95% CI 0.18-1.12, P = 0.081). The OR for the combined heterozygous state (677 CT and 1298 AC) was 1.18 (95% CI 0.52-2.64, P =0.697). INTERPRETATION & CONCLUSION: The frequency of the MTHFR 677 TT genotype is rare as compared to 1298 CC genotype in the population studied. There was no association between 677 C-->T and 1298 A-->C polymorphisms and risk of CRC either individually or in combination. The homozygous state for 1298 A-->C polymorphism appears to slightly lower risk of CRC. This needs to be confirmed with a larger sample size.
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Neoplasias Colorrectales/genética , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Polimorfismo Genético , Adolescente , Adulto , Anciano , Secuencia de Bases , Estudios de Casos y Controles , Neoplasias Colorrectales/epidemiología , Cartilla de ADN , Femenino , Frecuencia de los Genes , Humanos , India/epidemiología , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
Chemical probes that report on protein activity, rather than protein abundance, with spatial and temporal resolution can enable studies of their native function in biological contexts as well as provide opportunities for developing new types of biochemical reporters. Here we present a sensing platform, termed proximity-activated imaging reporter (PAIR), which combines activity-based methionine bioconjugation and antibody labeling with proximity-dependent oligonucleotide-based amplification to monitor dynamic changes of a given analyte in cells and animals through context-dependent methionine labeling of specific protein targets. We establish this PAIR method to develop sensors for imaging reactive oxygen species (ROS) and calcium ions through oxaziridine-directed labeling of reactive methionine residues on ß-actin and calmodulin (CaM), respectively, where the extent of methionine bioconjugation on these protein targets can serve as an indicator of oxidative stress or calcium status. In particular, application of PAIR to activity-based CaM detection provides a method for imaging integrated calcium activity in both in vitro cell and in vivo zebrafish models. By relying on native protein biochemistry, PAIR enables redox and metal imaging without introduction of external small molecules or genetically encoded indicators that can potentially buffer the natural/existing pools. This approach can be potentially generalized to target a broader range of analytes by pairing appropriate activity-based protein probes with protein detection reagents in a proximity-driven manner, providing a starting point not only for designing new sensors but also for monitoring endogenous activity of specific protein targets in biological specimens with spatial and temporal fidelity.
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Remethylation of homocysteine to methionine is dependent on an adequate supply of one or more of the B vitamins like folate, vitamin B(12) and vitamin B(6). Plasma total homocysteine (tHcy) is also influenced by genetic factors such as polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene. MTHFR is a flavo enzyme and a key player in folate metabolism and changes in its activity could modify the susceptibility to Acute Lymphoblastic Leukemia (ALL). In this case - control study we have examined the effect of riboflavin status as measured by erythrocyte glutathione reductase activation coefficient (EGRAC) on homocysteine levels along with vitamin B(12) and folate in pediatric ALL. Folate and B(12) levels were significantly lower among cases as compared to controls while EGRAC and tHcy did not differ significantly among the groups. The multivariate regression analysis revealed that in the ALL group EGRAC significantly influences tHcy levels suggesting that riboflavin availability may be a predictor of tHcy levels in patients with ALL. This finding may have implications for tHcy lowering therapy.
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Folate and cobalamin (Vitamin B(12)) are two essential micronutrients involved in one-carbon metabolism, which affects heart disease, neural tube defects and cancer. Methylenetetrahydrofolate reductase, the key enzyme involved in one carbon metabolism produces methyl tetrahydrofolate from methylene tetrahydrofolate, which in turn donates methyl group to homocysteine to generate methionine. There exist two common low function polymorphic variants of the methylenetetrahydrofolate reductase gene involving nucleotides 677 CâT and 1298 AâC, which are associated with hyperhomocysteinemia. These polymorphisms are also linked with increased risk for certain cancers such as breast cancer and at the same time providing a protective effect on colorectal cancer. In this case control study, we have evaluated levels of folic acid, vitamin B(12) and homocysteine in patients with colorectal cancer. Folate and homocysteine levels did not differ significantly between the two groups; however an increasing trend was noticed with increase in homocysteine levels. Vitamin B(12) levels were increased in cases compared to control group.
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HER-2 is overexpressed in approximately 20-30% of invasive Breast Cancer. ECD of the HER-2 protein is frequently cleaved and released into the circulation, where it can be detected by ELISA in up to 45% of patients with metastatic breast cancer. The objective of our study was to compare the current methods for the detection of HER-2 protein. Tissue HER-2 levels were studied in 100 breast cancer patients by IHC and compared with serum HER-2 levels by ELISA. IHC frequency was 29%. Serum HER-2 ECD was positive in 42% of patients. A statistically significant correlation was observed. HER-2 detected by IHC correlates significantly with serum HER-2 levels detected by ELISA. Thus, ELISA is a reliable and economical tool to assess the HER-2 status in tumors, when breast tissue sample is not available.
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Transition metals are essential, but deregulation of their metabolism causes toxicity. Here, we report that the compound NSC319726 binds copper to induce oxidative stress and arrest glioblastoma-patient-derived cells at picomolar concentrations. Pharmacogenomic analysis suggested that NSC319726 and 65 other structural analogs exhibit lethality through metal binding. Although NSC319726 has been reported to function as a zinc ionophore, we report here that this compound binds to copper to arrest cell growth. We generated and validated pharmacogenomic predictions: copper toxicity was substantially inhibited by hypoxia, through an hypoxia-inducible-factor-1α-dependent pathway; copper-bound NSC319726 induced the generation of reactive oxygen species and depletion of deoxyribosyl purines, resulting in cell-cycle arrest. These results suggest that metal-induced DNA damage may be a consequence of exposure to some xenobiotics, therapeutic agents, as well as other causes of copper dysregulation, and reveal a potent mechanism for targeting glioblastomas.