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BACKGROUND: The mediator of DNA damage checkpoint protein 1 (MDC1) is involved in the regulation of cell cycle checkpoints and recruitment of several repair proteins to the site of DNA double-stranded breaks (DSBs). This study aimed to correlate the expression of MDC1 protein with clinicopathological parameters and to evaluate its prognostic significance in patients with oral squamous cell carcinoma (OSCC). METHODS: MDC1 protein expression was evaluated immunohistochemically from untreated 100 patients with OSCC using modified H-score method. The association of MDC1 immunostaining was evaluated with clinicopathological parameters and disease outcome using univariate and multivariate survival analysis for relapse-free survival (RFS) and overall survival (OS). RESULTS: Incidence of nuclear and cytoplasmic expression of MDC1 protein was 85% & 92%, respectively. Strong nuclear MDC1 protein expression was found to be significantly correlated with lymph node metastasis (P = 0.032). For RFS, Kaplan-Meier survival analysis demonstrated that presence of metastatic lymph node (P = 0.001), lymphatic permeation (P = 0.020), and nuclear MDC1 (P = 0.005) remained significant risk predictors. In multivariate survival analysis, nuclear MDC1 (P = 0.027) entered at step 2 after presence of metastatic lymph node (P = 0.002) at step 1 for predicting reduced RFS. In relation to treatment, OSCC patients exhibiting weak expression of nuclear MDC1 protein were benefited significantly when treated with surgery followed by radiation therapy (P = 0.001). CONCLUSION: Thus, this study showed that MDC1 protein expression could be used as a prognostic marker in predicting relapse-free survival in patients with OSCC. OSCC patients expressing weak MDC1 protein could be benefited by adjuvant radiotherapy instead chemo-radiotherapy.
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Carcinoma de Células Escamosas/diagnóstico , Neoplasias de la Boca/diagnóstico , Proteínas Nucleares/análisis , Transactivadores/análisis , Proteínas Adaptadoras Transductoras de Señales , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/análisis , Carcinoma de Células Escamosas/química , Carcinoma de Células Escamosas/mortalidad , Proteínas de Ciclo Celular , Supervivencia sin Enfermedad , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/química , Neoplasias de la Boca/mortalidad , Pronóstico , Análisis de Supervivencia , Adulto JovenRESUMEN
An efficient synthetic approach to the core structure of the manzamine alkaloids is reported, particularly in relation to incorporating a one-carbon unit in ring B from which the aldehyde in ircinal A or the beta-carboline unit in manzamine A could potentially be generated. The key steps involve a Johnson-Claisen rearrangement, enolate alkylation, dithiane alkylation and a stereoselective intramolecular dipolar cycloaddition of an azomethine ylide, which provided the desired tricyclic ABC core structure.
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Carbazoles/síntesis química , Carbazoles/química , Cristalografía por Rayos X , Modelos Moleculares , Estructura MolecularRESUMEN
Multicomponent biomolecular self-assembly is fundamental for accomplishing complex functionalities of biosystems. Self-assembling peptides, amino acids, and their conjugates serve as a versatile platform for developing biomaterials. However, the co-assembly of multiple building blocks showing synergistic interplay between individual components and producing biomaterials with emergent functional attributes is much less explored. In this study, we have formulated minimalistic co-assembled hydrogels composed of Fmoc-phenylalanine and Fmoc-lysine. The co-assembled systems display broad-spectrum antimicrobial potency, a feature absent in individual building blocks. A comprehensive biophysical analysis demonstrates the physicochemical features of the hydrogels eliciting the antibacterial response. MD simulation further reveals a unique fibrillar architecture with Fmoc-phenylalanine forming the fibril core surrounded by positively charged Fmoc-lysine surface residues, thereby enhancing the interaction with negatively charged bacterial membranes, causing membrane disruption and cell death. Thus, this study provides molecular-level insight into the emergent properties of a multicomponent system, affording an excellent paradigm for developing novel biomaterials.
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Antibacterianos , Fluorenos , Hidrogeles , Lisina , Pruebas de Sensibilidad Microbiana , Fenilalanina , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Fenilalanina/química , Fenilalanina/farmacología , Fenilalanina/análogos & derivados , Hidrogeles/química , Hidrogeles/farmacología , Hidrogeles/síntesis química , Lisina/química , Fluorenos/química , Fluorenos/farmacología , Escherichia coli/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Simulación de Dinámica MolecularRESUMEN
Self-assembled peptide fibrils have been used extensively to template the organization of metal nanoparticles in a one-dimensional (1D) array. It has been observed that the formation of the 1D arrays with a width of a single or few nanoparticles (viz. 20 nm diameter) is only possible if the templating fibers have comparable diameters (viz. ≤20 nm). Accordingly, until today, all the peptide-based templates enabling such 1D arrays have very low persistence lengths, a property that depends strongly on the diameter of the template, owing to the inherent flexibility of only a few nanometer-wide fibers. Here, we demonstrate the formation of high persistence length 1D arrays templated by a short self-assembling peptide fibril with an asymmetrically distributed charged surface. The asymmetric nature of the peptide fibril allows charge-dependent deposition of the nanoparticles only to the part of the fiber with complementary charges, and the rest of the fibril surface remains free of nanoparticles. Consequently, fibers with a much higher diameter, which will have a higher persistence length, are able to template single or few nanoparticle-wide 1D arrays. Detailed microscopy, molecular dynamics simulations, and crystal structure analysis provide molecular-level insights into fiber asymmetry and its interactions with diverse nanostructures such as gold and magnetic nanoparticles. This study will afford an alternative paradigm for high persistence length 1D array fabrication comparable to DNA nanotechnology and lithography but with tremendous cost-effectiveness.
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Nanopartículas del Metal , Nanofibras , Nanoestructuras , Propiedades de Superficie , Oro/química , Nanoestructuras/química , Nanopartículas del Metal/química , Péptidos/químicaRESUMEN
PURPOSE: Nonhomologous end-joining (NHEJ) is critical for the repair of either pathologic double-strand breaks (DSBs) and/or for the repair of physiologic DSBs created during radiotherapy to kill the tumor cell. Therefore, patients with higher expression of NHEJ repair proteins might develop resistance to ionizing radiation, allowing the disease to recur. As cancer of the oral cavity is a serious health problem globally, the present study aimed to examine the expression of Ku70/80, X-ray repair cross-complementing protein 4 (XRCC4) and DNA ligase IV-core molecules of the NHEJ pathway in patients with oral cancer. MATERIALS AND METHODS: Protein expression of Ku70/80, XRCC4, and DNA ligase IV were studied by Immunohistochemistry and mRNA expression of Ku70 and Ku80 were studied using reverse transcription polymerase chain reaction. Data were analyzed statistically using SPSS. RESULTS: A univariate survival analysis revealed an association of Ku70 mRNA with shorter overall survival (OS). While protein expression of XRCC4 showed an association with reduced relapse-free survival and shorter OS. Multivariate survival analysis demonstrated that XRCC4 and DNA ligase IV are independent prognosticators for predicting adverse disease outcomes. CONCLUSION: Strong expression of repair proteins - XRCC4 and DNA ligase IV is associated with unfavorable disease outcome in patients with oral squamous cell carcinoma.
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Biomarcadores de Tumor/metabolismo , Carcinoma de Células Escamosas/patología , Reparación del ADN por Unión de Extremidades , Reparación del ADN , Neoplasias de la Boca/patología , Recurrencia Local de Neoplasia/patología , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/terapia , Terapia Combinada , ADN Ligasa (ATP)/genética , ADN Ligasa (ATP)/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Femenino , Estudios de Seguimiento , Humanos , Autoantígeno Ku/genética , Autoantígeno Ku/metabolismo , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/genética , Neoplasias de la Boca/metabolismo , Neoplasias de la Boca/terapia , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/metabolismo , Recurrencia Local de Neoplasia/terapia , Pronóstico , Tasa de Supervivencia , Adulto JovenRESUMEN
The cross talk between different membrane receptors is the source of increasing research. We designed and synthesized a new hetero-bivalent ligand that has antagonist properties on both A(1) adenosine and mu opiate receptors with a K(i) of 0.8+/-0.05 and 0.7+/-0.03 microM, respectively. This hybrid molecule increases cAMP production in cells that over express the mu receptor as well as those over expressing the A(1) adenosine receptor and reverses the antalgic effects of mu and A(1) adenosine receptor agonists in animals.
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Antagonistas del Receptor de Adenosina A1 , Adenosina/análogos & derivados , Anilidas/farmacología , Diseño de Fármacos , Receptores Opioides mu/antagonistas & inhibidores , Adenosina/síntesis química , Adenosina/química , Adenosina/farmacología , Anilidas/síntesis química , Anilidas/química , Ligandos , Estructura Molecular , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
INTRODUCTION: 5-flourouracil (5-FU) is one of the standard chemotherapeutic drugs used today in the treatment of colorectal cancer patients. Disruption of 5-FU metabolic pathway may contribute to altered effectiveness towards 5-FU-based therapy. Hence, the study of 5-FU metabolizing enzymes might have the potential efficacy to predict survival and response to treatment in colorectal cancer patients. MATERIALS AND METHODS: Immunohistochemical localization of 5-FU metabolic enzymes (TS, MTHFR, DPYD, and TP) was evaluated in 143 untreated patients with colorectal cancer; their prognostic and predictive values were also evaluated. RESULTS: Immuno-positivity for TS, MTHFR, DPYD, and TP was observed in 77%, 75%, 88%, and 96% of colorectal cancer patients, respectively. Univariate survival analysis in total patients showed that low DPYD expression significantly predicted adverse overall survival ( P=0.042). Moreover, subgroup of colon cancer patients with low TS expression was associated with unfavorable prognosis. TP expression also emerged as a prognosticator in the subgroup of early and advanced stage patients. Additionally, when effect of co-expression of 5-FU metabolic enzymes was evaluated in total patients, low coexpression of all four proteins was predictive of poor overall survival than for individuals expressing high coexpression of these proteins ( P=0.045). In contrast, none of the 5-FU metabolic enzymes-either singly or on coexpression-emerged as a useful biomarker of potential therapeutic value when evaluated in the subgroup of patients treated with 5-FU alone or 5-FU plus oxaliplatin. CONCLUSION: The above findings suggest that coexpression of 5-FU metabolic enzymes possess significant prognostic value and could be useful biomarkers in colorectal cancer patients.
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Neoplasias Colorrectales/tratamiento farmacológico , Dihidrouracilo Deshidrogenasa (NADP)/genética , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Timidina Fosforilasa/genética , Timidilato Sintasa/genética , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/inmunología , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/inmunología , Neoplasias Colorrectales/patología , Femenino , Fluorouracilo/uso terapéutico , Regulación Enzimológica de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Inactivación Metabólica/genética , Inactivación Metabólica/inmunología , Masculino , Persona de Mediana Edad , Pronóstico , Resultado del TratamientoRESUMEN
PURPOSE: Uncontrolled cytokine signal transduction largely associated with oncogene activation, can have disastrous biological consequences. The suppressor of cytokine signaling (SOCS) proteins represent one of the mechanisms by which this rampant signaling can be dissipated. Thus, we aimed to study the expression of SOCS-1, SOCS-2, and SOCS-3 in patients having benign thyroid disease and papillary thyroid cancer. MATERIALS AND METHODS: SOCS protein expression was studied in 45 patients with benign thyroid disease and in 83 papillary thyroid cancer patients by immunohistochemistry and their association with clinicopathological characteristics and overall survival in cancer patients were analyzed using SPSS software. RESULTS: Expressions of SOCS proteins were significantly higher in papillary thyroid cancer than in patients having benign disease. SOCS-1 expression was predominantly higher in males (P = 0.004), unilateral tumors (P = 0.030), and noninflammatory conditions (P = 0.028). SOCS-1 expression was also able to predict poor overall survival in subgroup of papillary thyroid cancer patients having larger tumor size (P = 0.013) and advanced stage disease (P = 0.033). Expression of SOCS-2 significantly correlated with tumor size (P = 0.017), extrathyroidal extension (P = 0.000), residual disease (P = 0.043), and treatment (P = 0.007), while preponderance of SOCS-3 expression was observed in males (P = 0.030) and in patients having extrathyroidal extension (P = 0.011) and absence of metastasis (P = 0.032). CONCLUSION: Expression of the studied SOCS proteins may be a consequence of activation of Janus kinase-signal transducers and activators of transcription and other pathways supporting growth and survival of cancer cells that are sustained by several cytokines. Thus, SOCS-1, SOCS-2, and SOCS-3 proteins may directly or indirectly, have important roles in development and pathogenesis of papillary thyroid cancer.
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Carcinoma Papilar/metabolismo , Proteína 1 Supresora de la Señalización de Citocinas/metabolismo , Proteína 3 Supresora de la Señalización de Citocinas/metabolismo , Proteínas Supresoras de la Señalización de Citocinas/metabolismo , Neoplasias de la Tiroides/metabolismo , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Transducción de Señal , Análisis de Supervivencia , Cáncer Papilar TiroideoRESUMEN
Circulating levels of TNF-α and the adhesion molecules L-Selectin and VCAM-1 as well as their expression in the primary tumors of patients with benign thyroid diseases and papillary thyroid carcinoma (PTC) have been determined in this study. The serum levels of TNF-α, L-Selectin, and VCAM-1 were significantly higher in patients with both benign thyroid diseases and PTC as compared to the healthy individuals. However, the levels of only TNF-α and L-Selectin, and not VCAM-1, were significantly higher in patients with PTC in comparison to those observed in patients with benign thyroid diseases. Further the expression of TNF-α and L-Selectin was also significantly higher in the primary tumors of PTC patients, relative to the benign thyroid diseases. The expression of L-Selectin and VCAM-1 significantly correlated with aggressive tumor behavior. In PTC patients, the circulating TNF-α levels significantly positively correlated with the levels of L-Selectin, while TNF-α immunoreactivity was significantly associated with VCAM-1 expression. Serum TNF-α was found to be a significant prognosticator for OS in PTC patients. Overall the results signify that the interaction between TNF-α and the adhesion molecules may have a role in thyroid carcinogenesis and understanding this complexity may offer potential therapeutic targets for better management of thyroid cancer.
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This study sought to reveal the significance of IL-6 in papillary thyroid carcinoma by determining its circulating levels, tumoral protein, and mRNA expressions. As compared to the healthy individuals, serum IL-6 was significantly higher in patients with benign thyroid diseases and PTC. Further, its level was significantly higher in PTC patients as compared to patients with benign thyroid diseases. ROC curves also confirmed a good discriminatory efficacy of serum IL-6 between healthy individuals and patients with benign thyroid diseases and PTC. The circulating IL-6 was significantly associated with poor overall survival in PTC patients. IL-6 immunoreactivity was significantly high in PTC patients as compared to the benign thyroid disease patients. Significantly higher IL-6 mRNA expression was also observed in the primary tumour tissues of PTC patients than the adjacent normal tissues. The protein expression of IL-6 at both the circulating and tissue level correlated with disease aggressiveness in PTC patients. Moreover, a significant positive correlation was observed between the IL-6 protein and mRNA expression in the primary tumours of PTC patients. Finally in conclusion, IL-6 has an important role in thyroid cancer progression. Thus targeting IL-6 signalling can help in clinical management of thyroid carcinoma patients.
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In fluorescence quenching study via electron transfer (ET), the quenching rate constant (k(q)) values generally decrease with lowering of quencher concentration, since smaller concentration of quencher always leads to a red shift in the donor-acceptor (D-A) distance in ET [M. Tachiya, S. Murata, J. Phys. Chem. 96 (1992) 8441; S. Murata, M. Tachiya, J. Phys. Chem. 100 (1996) 4064; L. Burel, M. Mastafavi, S. Murata, M. Tachiya, J. Phys. Chem. A 103 (1999) 5882]. However, while doing a comparative study with different carbazole (CZ) derivatives-1,4-dicyanobenzene (DCB) systems in benzene (BZ), we observed a deviation from that normal behaviour. It was found that for all of them with lower quencher (DCB) concentration, k(q) values actually increase instead of the expected reduction. Exceptionally, for simple CZ (C12H9N) with decrease in concentration of DCB, k(q) values can even reach the order of energy transfer (10(11) s(-1)). Interestingly, it is not observed when toluene (TL) or xylene (XY) is used as solvent. To explain this unique observation, a sandwich type of molecular structure is predicted, where BZ sliding in between CZ and DCB brings them closer enough, imparting more through bond character to CZ-DCB interaction and hence a higher rate of ET (k(q)) is observed [L. Burel, M. Mastafavi, S. Murata, M. Tachiya, J. Phys. Chem. A. 103 (1999) 5882].
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Benceno/química , Espectrofotometría/métodos , Electrones , Transferencia de Energía , Hidrógeno/química , Cinética , Conformación Molecular , Estructura Molecular , Solventes , EstereoisomerismoRESUMEN
In this communication we have reported the steric effect on the fluorescence quenching rate constants of the electron transfer (ET) process. We have done a comparative study using donor (D)-acceptor (A) systems with different exergonicity (-deltaG(f)). Different carbazole derivatives (CZ): 1,4-dicyanobenzene (DCB) systems (-deltaG(f) = 0.7-0.8 eV) were found to be among those limiting systems that show a clear-cut steric dominance in the process of fluorescence quenching. It is known that with increasing exergonicity the ET distance increases and hence steric dependence becomes insignificant. On the other hand, with decreasing exergonicity the ET distance decreases and a pronounced steric dominance should be observed. However, in the D-A systems having lower exergonicity compared to CZ-DCB systems, this steric dominance is observed only in polar medium. In non-polar medium due to exciplex formation the D-A distance effectively becomes much longer and therefore no steric dominance is observed.
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Carbazoles/química , Nitrilos/química , Transporte de Electrón , Fluorescencia , Espectrometría de FluorescenciaRESUMEN
With the advent of spin chemistry, magnetic field effect (MFE) on exciplex luminescence has emerged as an important domain of research. MFE is a diffusion controlled phenomenon and hence is solvent dielectric (epsilon) dependent. It maximizes at a particular epsilon (epsilon(max)) for a specific exciplex system. Various attempts have been made to explain the variation of this epsilon(max) from one exciplex to another. In our present work we have succeeded for the first time to enmark the energy of exciplex (E(ex)) as the prime factor in determining the epsilon(max). We have indicated a definite inverse correlation (1:1) between epsilon(max) and E(ex). We have also tried to correlate some parameters that are important in exciplex formation, e.g. Charton's steric constant (nu(c)), repulsive energy (R(e)) and E(ex).
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Campos Electromagnéticos , Magnetismo , Espectrofotometría/métodos , Carbazoles/química , Cianuros/química , Cinética , Modelos Químicos , Temperatura , TermodinámicaRESUMEN
CC-1065, the duocarmycins and yatakemycin are members of a family of ultrapotent antitumour antibiotics that have been the subject of extensive investigations due to their mode of action and potential in the design of new anticancer therapeutics. The natural products and their analogues exert their effects through a sequence selective alkylation of duplex DNA in the minor groove at the N3 of adenine. An understanding of their structure and its effect on biological activity has been derived through chemical synthesis and has also generated new potential lead compounds. These studies form the first section of the review. The desire to progress these compounds to clinic has also led to studies of bioconjugation and prodrug formation and this is discussed in the second section of the review. The combination of synthesis with key biological experiments is a powerful tool to define the requirements for the development of natural products as potential therapeutic agents. The studies described herein form an excellent paradigm for the study and development of other natural products.