Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
Anticancer Agents Med Chem ; 21(10): 1266-1274, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33023458

RESUMO

BACKGROUND: There is an urgent need to devise improved alternatives for the efficient delivery of drugs to develop improved therapeutic interventions against cancers. Nanotechnology-based drug delivery vehicles are in-use with obvious issues of toxicity and bio-distribution. Therefore, green synthetic routes are being deployed to replace the conventional nanoparticle formulations for effective drug delivery aiming at developing interventional strategies against cancer. OBJECTIVE: A simple, viable, and fast approach was used for the green synthesis of silver nanoparticles (AgNPs) using aqueous leaf-extract of Viburnum nervosum (VN) and to explore the anti-cancer potential of the crude extract of VN. METHODS: Silver NPs were synthesized by reacting silver nitrate (AgNO3) with leaf extract of VN. Various analytical techniques were used to characterize the AgNPs. Finally, the anti-cancer potential of VN was observed when delivered through AgNPs. RESULTS: The surface plasmon spectra for AgNPs exhibited absorbance peak at 445 nm, and Fourier-Transform Infrared Spectroscopy investigation revealed the presence of biomolecules acting as an effective reducing and capping agent for converting silver nitrate to AgNPs. Further, our results suggest the spherical size of synthesized AgNPs ranging from 12-17 nm. Moreover, in vitro studies conducted for VN extract with breast (MCF-7) and epidermal carcinoma (A431) cells showed biocompatibility. CONCLUSION: Doxorubicin loaded AgNPs documented an increased bioavailability of the drug compared to the free drug, suggesting the use of AgNPs as "novel drug delivery vectors".


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Química Verde , Nanopartículas Metálicas/química , Extratos Vegetais/farmacologia , Prata/farmacologia , Viburnum/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Tamanho da Partícula , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Prata/química , Relação Estrutura-Atividade , Propriedades de Superfície
2.
Expert Rev Mol Diagn ; 20(5): 533-541, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32151178

RESUMO

Introduction: Tuberculosis (TB) is still one of the major global health threats and delayed diagnosis or misdiagnosis continues to fuel the global epidemic. The conventional diagnostic approaches have shortcomings that might hinder the process of diagnosis of the disease and ultimately affect the prognosis.Area covered: We emphasize on the process of the synthesis of liposomes, its physicochemical properties affecting the formulation and their utilization in the field of molecular diagnostics for TB. The review also sheds a light on other nanoparticle-based molecular diagnostic approaches for TB. Despite the advent of science, we are yet to have a diagnostic tool that is simple, rapid, sensitive, and specific, and most importantly, one that enables us to demarcate patients with active tuberculosis from those with quiescent lesions, prior vaccination, or other diseases.Expert opinion: The utility of liposomes for diagnostic purposes has been attempted so as to overcome the challenges posed by conventional diagnostic tools for TB. Through this review, we present insights into liposome formulation and selection processes, various studies that report the use of liposome-based diagnostic tools for TB, as well as the limitations associated with the same that can be improvised to make the technology more efficient.


Assuntos
Lipossomos , Técnicas de Diagnóstico Molecular , Mycobacterium tuberculosis , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/microbiologia , Tuberculose/diagnóstico , Tuberculose/microbiologia , Humanos , Lipossomos/química , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/normas , Nanopartículas/química , Sensibilidade e Especificidade , Nanomedicina Teranóstica
3.
Curr Comput Aided Drug Des ; 16(2): 176-189, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31429692

RESUMO

INTRODUCTION: Intermediate covalent complex of DNA-Topoisomerase II enzyme is the most promising target of the anticancer drugs to induce apoptosis in cancer cells. Currently, anticancer drug and chemotherapy are facing major challenges i.e., drug resistance, chemical instability and, dose-limiting side effect. Therefore, in this study, natural therapeutic agents (series of Ganoderic acids) were used for the molecular docking simulation against Human DNATopoisomerase II beta complex (PDB ID:3QX3). METHODS: Molecular docking studies were performed on a 50 series of ganoderic acids reported in the NCBI-PubChem database and FDA approved anti-cancer drugs, to find out binding energy, an interacting residue at the active site of Human DNA-Topoisomerase II beta and compare with the molecular arrangements of the interacting residue of etoposide with the Human DNA topoisomerase II beta. The autodock 4.2 was used for the molecular docking and pharmacokinetic and toxicity studies were performed for the analysis of physicochemical properties and to check the toxicity effects. Discovery studio software was used for the visualization and analysis of docked pose. RESULTS AND CONCLUSION: Ganoderic acids (GS-1, A and DM) were found to be a more suitable competitor inhibitor among the ganoderic acid series with appropriate binding energy, pharmacokinetic profile and no toxicity effects. The interacting residue (Met782, DC-8, DC-11 and DA-12) shared a chemical resemblance with the interacting residue of etoposide present at the active site of human topoisomerase II beta receptor.


Assuntos
Antineoplásicos/química , DNA Topoisomerases Tipo II/química , Simulação de Acoplamento Molecular , Inibidores da Topoisomerase II/química , Relação Estrutura-Atividade , Triterpenos
4.
Immunotherapy ; 11(13): 1129-1147, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31390917

RESUMO

A wide array of therapeutic strategies has been implemented against cancers, yet their clinical benefit is limited. The lack of clinical efficacy of the conventional treatment options might be due to the inept immune competency of the patients. Dendritic cells (DCs) have a vital role in initiating and directing immune responses and have been frequently used as delivery vehicles in clinical research. The recent clinical data suggest the potential use of DCs pulsed with nucleic acid, especially with RNA holds a great potential as an immunotherapeutic measure with compare to other cancer therapeutics. This review mainly deals with the DCs and their role in transfection with RNA in cancer immunotherapy.


Assuntos
Vacinas Anticâncer/imunologia , Células Dendríticas/fisiologia , Imunoterapia/métodos , Neoplasias/terapia , RNA/genética , Animais , Apresentação de Antígeno/genética , Células Dendríticas/transplante , Humanos , Tolerância Imunológica , Imunidade , Neoplasias/imunologia , Transfecção , Microambiente Tumoral
5.
Phytomedicine ; 50: 127-136, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30466971

RESUMO

BACKGROUND: Withania somnifera, a high value medicinal plant is a major source of pharmaceutically important active compounds withanolides. Withania somnifera has been used in ayurveda as health restorative and anabolic agent besides having anti-arthritic, antidepressant, anti-microbial, anti-inflammatory, anti-diabetic, anti-stress, neuroprotective and cardio-protective activities. HYPOTHESIS/PURPOSE: The mining of the compound(s) of interest offers opportunity to identify desired attributes in the therapeutic area of interest. Metabolomic has become an important tool in the field of pharmacological and functional genomics of medicinal plants. The analysis supports the information regarding differential outline of the gene expression for increasing important withanolides viz. withanolide A and withaferin A in W. somnifera. STUDY DESIGN: The bioinformatics and biotechnological approaches viz. tissue culture, genetic transformation, genomic, transcriptomic, proteomic, gene mining and metabolomic studies have opened new windows about engineering of withanolide production. METHODS: Target and network analysis for maximum therapeutic potential of Withania somnifera have been determined by employing Genemania software for finding interactions among various human genes that are being affected by active constituents. RESULTS: Some of the major bioactive compounds of Withania somnifera have been discussed on protein-protein, protein-DNA and genetic interactions with respect to gene and protein expression data, protein domains, metabolic profiling, root organ culture, genetic transformation and phenotypic screening profiles CONCLUSION: The implementation of latest bioinformatic tools in combination with biotechnological techniques for breeding platforms are important in conservation of medicinal plant species in danger. The current review is based on molecular and in vitro methodologies employed in W. somnifera for accepting their importance in the improvement of this valuable medicinal species.


Assuntos
Metabolômica , Compostos Fitoquímicos/farmacologia , Withania/química , Biologia Computacional , Humanos , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Plantas Medicinais/genética , Proteômica , Técnicas de Cultura de Tecidos , Withania/genética , Vitanolídeos/farmacologia
6.
Protein Pept Lett ; 25(5): 492-499, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29623820

RESUMO

BACKGROUND: Breast cancer demands safe adjuvant to overcome the side effects of standard drug tamoxifen. Diet derived bioactive compounds are reported to exhibit modulation of cancer growth leading to cell death. Chickpea is a protein rich edible legume with several bioactive compounds that includes lectin as well. Characterization of chickpea lectin for its effect against cancer cells has been investigated in this study. METHOD: Cicer arietinum L. lectin (CAL) agglutinating trypsin-treated rabbit blood cells was purified employing DEAE-cellulose and SP-sephadex ion exchange chromatography. The lectin was characterized for its biological activity vis-à-vis antiproliferative and apoptotic effects through cell cycle arrest in MCF-7 human breast cancer cells. RESULT: There is a significant inhibition of the survival of breast cancer cells due to chickpea lectin in a dose dependent manner for 24 hr. Lectin treated cells revealed distinct features of apoptosis. Flow cytometric analysis at 80 µg/ml of lectin induced S and G2 phase cell cycle arrest. CAL induced apoptosis in MCF-7 cells associated with lactate dehydrogenase leakage, cell cycle arrest and reactive oxygen species generation. CONCLUSION: Our studies show that chickpea lectin exerted anticancer activity and could be exploited as an essential source for medicine leading to the treatment of breast cancer.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Ciclo Celular/efeitos dos fármacos , Cicer/química , Lectinas de Plantas/farmacologia , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Feminino , Humanos , Células MCF-7 , Lectinas de Plantas/química , Coelhos
7.
PLoS One ; 10(11): e0141719, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26536350

RESUMO

Oral cancer is one of the main causes of cancer-related deaths in South-Asian countries. There are very limited treatment options available for oral cancer. Research endeavors focused on discovery and development of novel therapies for oral cancer, is necessary to control the ever rising oral cancer related mortalities. We mined the large pool of compounds from the publicly available compound databases, to identify potential therapeutic compounds for oral cancer. Over 84 million compounds were screened for the possible anti-cancer activity by custom build SVM classifier. The molecular targets of the predicted anti-cancer compounds were mined from reliable sources like experimental bioassays studies associated with the compound, and from protein-compound interaction databases. Therapeutic compounds from DrugBank, and a list of natural anti-cancer compounds derived from literature mining of published studies, were used for building partial least squares regression model. The regression model thus built, was used for the estimation of oral cancer specific weights based on the molecular targets. These weights were used to compute scores for screening the predicted anti-cancer compounds for their potential to treat oral cancer. The list of potential compounds was annotated with corresponding physicochemical properties, cancer specific bioactivity evidences, and literature evidences. In all, 288 compounds with the potential to treat oral cancer were identified in the current study. The majority of the compounds in this list are natural products, which are well-tolerated and have minimal side-effects compared to the synthetic counterparts. Some of the potential therapeutic compounds identified in the current study are resveratrol, nimbolide, lovastatin, bortezomib, vorinostat, berberine, pterostilbene, deguelin, andrographolide, and colchicine.


Assuntos
Algoritmos , Antineoplásicos/farmacologia , Bases de Dados de Produtos Farmacêuticos , Bases de Dados de Proteínas , Modelos Estatísticos , Neoplasias Bucais/tratamento farmacológico , Neoplasias Bucais/patologia , Administração Oral , Berberina/farmacologia , Bortezomib/farmacologia , Colchicina/farmacologia , Diterpenos/farmacologia , Humanos , Ácidos Hidroxâmicos/farmacologia , Limoninas/farmacologia , Lovastatina/farmacologia , Valor Preditivo dos Testes , Resveratrol , Rotenona/análogos & derivados , Rotenona/farmacologia , Estilbenos/farmacologia , Máquina de Vetores de Suporte , Vorinostat
8.
PLoS One ; 9(7): e102610, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25029526

RESUMO

In India, oral cancer has consistently ranked among top three causes of cancer-related deaths, and it has emerged as a top cause for the cancer-related deaths among men. Lack of effective therapeutic options is one of the main challenges in clinical management of oral cancer patients. We interrogated large pool of samples from oral cancer gene expression studies to identify potential therapeutic targets that are involved in multiple cancer hallmark events. Therapeutic strategies directed towards such targets can be expected to effectively control cancer cells. Datasets from different gene expression studies were integrated by removing batch-effects and was used for downstream analyses, including differential expression analysis. Dependency network analysis was done to identify genes that undergo marked topological changes in oral cancer samples when compared with control samples. Causal reasoning analysis was carried out to identify significant hypotheses, which can explain gene expression profiles observed in oral cancer samples. Text-mining based approach was used to detect cancer hallmarks associated with genes significantly expressed in oral cancer. In all, 2365 genes were detected to be differentially expressed genes, which includes some of the highly differentially expressed genes like matrix metalloproteinases (MMP-1/3/10/13), chemokine (C-X-C motif) ligands (IL8, CXCL-10/-11), PTHLH, SERPINE1, NELL2, S100A7A, MAL, CRNN, TGM3, CLCA4, keratins (KRT-3/4/13/76/78), SERPINB11 and serine peptidase inhibitors (SPINK-5/7). XIST, TCEAL2, NRAS and FGFR2 are some of the important genes detected by dependency and causal network analysis. Literature mining analysis annotated 1014 genes, out of which 841 genes were statistically significantly annotated. The integration of output of various analyses, resulted in the list of potential therapeutic targets for oral cancer, which included targets such as ADM, TP53, EGFR, LYN, CTLA4, SKIL, CTGF and CD70.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Regulação Neoplásica da Expressão Gênica/genética , Neoplasias Bucais/tratamento farmacológico , Neoplasias Bucais/metabolismo , Proteínas de Neoplasias/metabolismo , Adrenomedulina/metabolismo , Ligante CD27/metabolismo , Antígeno CTLA-4/metabolismo , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Mineração de Dados , Receptores ErbB/metabolismo , Perfilação da Expressão Gênica/métodos , Humanos , Índia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Anotação de Sequência Molecular , Neoplasias Bucais/genética , Proteínas de Neoplasias/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Quinases da Família src/metabolismo
9.
Mol Diagn Ther ; 18(5): 483-94, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24838674

RESUMO

Oral cancer is one of the most commonly found cancers in many South-Asian underdeveloped countries, especially among men in comparison to women. When considering the mortality rate among all types of existing cancers, in India oral cancer is the primary reason for death in men. Some of the major reasons contributing to the high mortality rate are late diagnosis, lack of treatment options and high prevalence of tobacco consumption. Oral cancer is often diagnosed at a stage when cancer cells have already become aggressive and become resistant to standard therapeutic options. Progression, apoptosis, angiogenesis, metastasis and invasion behold great capability to treat and detect cancer at the molecular level. Dysregulation of apoptosis is one of the most common molecular events known to be associated with the development of oral cancer. In this review, we discuss key apoptotic markers which can be used as prognostic and/or therapeutic targets in oral cancer.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Bucais/diagnóstico , Neoplasias Bucais/tratamento farmacológico , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose , Detecção Precoce de Câncer , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Neoplasias Bucais/metabolismo , Prognóstico , Transdução de Sinais/efeitos dos fármacos
10.
Biochim Biophys Acta ; 1836(1): 123-45, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23602834

RESUMO

Cancer is a class of diseases characterized by uncontrolled cell growth. The development of cancer takes place in a multi-step process during which cells acquire a series of mutations that eventually lead to unrestrained cell growth and division, inhibition of cell differentiation, and evasion of cell death. Dysregulation of oncoapoptotic genes, growth factors, receptors and their downstream signaling pathway components represent a central driving force in tumor development. The detailed studies of signal transduction pathways for mechanisms of cell growth and apoptosis have significantly advanced our understanding of human cancers, subsequently leading to more effective treatments. Oral squamous cell carcinoma represents a classic example of multi-stage carcinogenesis. It gradually evolves through transitional precursor lesions from normal epithelium to a full-blown metastatic phenotype. Genetic alterations in many genes encoding crucial proteins, which regulate cell proliferation, differentiation, survival and apoptosis, have been implicated in oral cancer. As like other solid tumors, in oral cancer these genes include the ones coding for cell cycle regulators or oncoproteins (e.g. Ras, Myc, cyclins, CDKs, and CKIs), tumor suppressors (e.g. p53 and pRb), pro-survival proteins (e.g. telomerase, growth factors or their receptors), anti-apoptotic proteins (e.g. Bcl2 family, IAPs, and NF-kB), pro-apoptotic proteins (e.g. Bax and BH-3 family, Fas, TNF-R, and caspases), and the genes encoding key transcription factors or elements for signal transduction leading to cell growth and apoptosis. Here we discuss the current knowledge of oncoapoptotic regulation in human cancers with special reference to oral cancers.


Assuntos
Antineoplásicos/farmacologia , Proteínas Reguladoras de Apoptose/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Transformação Celular Neoplásica/efeitos dos fármacos , Neoplasias Bucais/genética , Animais , Humanos , Neoplasias Bucais/tratamento farmacológico , Neoplasias Bucais/patologia
11.
J Immunol Methods ; 387(1-2): 157-66, 2013 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-23098841

RESUMO

HIV (human immunodeficiency virus) infection has now become endemic worldwide and AIDS ranks fourth among the world's top killers of mankind. A rapid and accurate HIV testing assay is a pre-requisite for practical applicability of diagnostic tests. The aim of this present study was to design peptide cocktail as an antigen and to develop ELISA test for HIV-1/2 antibody detection, with enhanced sensitivity and specificity. A novel peptide stretch V3-I, covering immunodominant epitope corresponding to V3 hypervariable loop of gp120 antigens of selected Indian isolates, has been studied and incorporated in an antigenic cocktail of gp36, gp41, and rp24 of HIV-1/2. Peptides from these antigens were chemically synthesized and an additional cysteine residue was added at both amino- and carboxyl-terminal sequences of each peptide in order to form inter and intramolecular disulfide bond for the folding of peptides. This generated conformational epitopes with increased oligomericity and stability of peptide sequences; and attachment of antigen to the solid support of ELISA plates. The use of antigenic cocktail of folded peptides and recombinant p24 enhanced sensitivity and specificity of the ELISA test. Evaluation of the test using 1123 serum samples in comparison with Boston Biomedical Incorporation (BBI) panels showed 100% sensitivity and 99.3% specificity with no cross reactivity tribulation. In conclusion, "HIV screen test" detects HIV 1/2 antibodies with a high degree of sensitivity and specificity and could be a promising tool for seroscreening of blood during transfusion, counseling and diagnosis of HIV-1/2.


Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Anticorpos Anti-HIV/imunologia , Antígenos HIV/imunologia , HIV-1/imunologia , HIV-2/imunologia , Peptídeos/imunologia , Sequência de Aminoácidos , Cisteína/química , Cisteína/imunologia , Anticorpos Anti-HIV/análise , Anticorpos Anti-HIV/sangue , Antígenos HIV/química , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/imunologia , Proteína gp41 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/imunologia , Infecções por HIV/diagnóstico , Infecções por HIV/imunologia , Infecções por HIV/virologia , Proteínas do Vírus da Imunodeficiência Humana/química , Proteínas do Vírus da Imunodeficiência Humana/imunologia , Humanos , Dados de Sequência Molecular , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
12.
Mol Diagn Ther ; 16(6): 371-81, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23184341

RESUMO

Acute myocardial infarction (AMI) is the leading cause of death worldwide, with early diagnosis still being difficult. Promising new cardiac biomarkers such as troponins and creatine kinase (CK) isoforms are being studied and integrated into clinical practice for early diagnosis of AMI. The cardiac-specific troponins I and T (cTnI and cTnT) have good sensitivity and specificity as indicators of myocardial necrosis and are superior to CK and its MB isoenzyme (CK-MB) in this regard. Besides being potential biologic markers, cardiac troponins also provide significant prognostic information. The introduction of novel high-sensitivity troponin assays has enabled more sensitive and timely diagnosis or exclusion of acute coronary syndromes. This review summarizes the available information on the potential of troponins and other cardiac markers in early diagnosis and prognosis of AMI, and provides perspectives on future diagnostic approaches to AMI.


Assuntos
Biomarcadores , Infarto do Miocárdio/classificação , Infarto do Miocárdio/diagnóstico , Triagem/métodos , Troponina I/fisiologia , Troponina T/fisiologia , Biomarcadores/análise , Biomarcadores/sangue , Biomarcadores/metabolismo , Diagnóstico Precoce , Humanos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/normas , Infarto do Miocárdio/sangue , Infarto do Miocárdio/terapia , Miocárdio/metabolismo , Prognóstico , Sensibilidade e Especificidade , Troponina I/análise , Troponina I/sangue , Troponina I/metabolismo , Troponina T/análise , Troponina T/sangue , Troponina T/metabolismo
13.
Curr Gene Ther ; 12(6): 444-53, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22974420

RESUMO

Survivin is known to be highly-expressed in various carcinomas; and is associated with their biologically aggressive characteristics and drug resistance. We have previously reported survivin as an important anti-apototic protein involved in head and neck squamous cell carcinoma (HNSCC) tumorigenesis and providing resistance to conventional cancer therapies. The purpose of present study was to investigate the potential of survivin as a therapeutic target in HNSCC. This study was designed to explore the effect(s) of survivin-siRNA therapy on the apoptosis in HNSCC cells, and its influence on cisplatin-sensitivity. Lentivirus vector was developed to deliver survivin specific siRNA into cancer cells. The data indicates that silencing of survivin-mediated by Lentivirus-siRNA therapy effectively suppressed cancer cell proliferation and induced caspase-dependent apoptosis in HNSCC cells. The study also shows that the response of HNSCC cells to cisplatin drug treatment at clinically relevant level was limited. We observed survivin to be a key factor involved in this cisplatin-resistance mechanism, and down-regulation of survivin significantly increased sensitivity of cancer cells to cisplatin-mediated apoptosis. Thus, this combination therapy acts as a multimodality regimen with significant potential to improve clinical outcomes in head and neck cancers.


Assuntos
Apoptose , Carcinoma de Células Escamosas/patologia , Cisplatino/farmacologia , Inativação Gênica , Neoplasias de Cabeça e Pescoço/patologia , Proteínas Inibidoras de Apoptose/metabolismo , Antineoplásicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Western Blotting , Carcinoma de Células Escamosas/genética , Linhagem Celular Tumoral , Proliferação de Células , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Neoplasias de Cabeça e Pescoço/genética , Humanos , Marcação In Situ das Extremidades Cortadas , Proteínas Inibidoras de Apoptose/genética , Lentivirus/genética , Lentivirus/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Survivina
14.
Curr Drug Targets ; 12(7): 1082-93, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21443470

RESUMO

Cyclooxygenase-2 (Cox-2) is an inducible enzyme involved in the conversion of arachidonic acid to prostaglandin and other eicosanoids. Molecular pathology studies have revealed that Cox-2 is over-expressed in cancer and stroma cells during tumor progression, and anti-cancer chemo-radiotherapies induce expression of Cox-2 in cancer cells. Elevated tumor Cox-2 is associated with increased angiogenesis, tumor invasion and promotion of tumor cell resistance to apoptosis. Several experimental and clinical studies have established potent anti-cancer activity of NSAID (Non-steroidal anti-inflammatory drugs) and other Cox-2 inhibitors such as celecoxib. Much attention is being focused on Cox-2 inhibitors as beneficial target for cancer chemotherapy. The mode of action of Cox-2 and its inhibitors remains unclear. Further clinical application needs to be investigated for comprehending Cox-2 biological functions and establishing it as an effective target in cancer therapy.


Assuntos
Inibidores de Ciclo-Oxigenase 2/farmacologia , Ciclo-Oxigenase 2/metabolismo , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/farmacologia , Ácido Araquidônico/metabolismo , Ciclo-Oxigenase 2/efeitos dos fármacos , Progressão da Doença , Sistemas de Liberação de Medicamentos , Humanos , Neoplasias/enzimologia
15.
Radiother Oncol ; 96(2): 267-73, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20638740

RESUMO

BACKGROUND: Oxaliplatin is integrated in treatment strategies against a variety of cancers including radiation protocols. Herein, as a new strategy we tested feasibility and rationale of oxaliplatin in combination with radiation to control proliferation of head and neck squamous cell carcinoma (HNSCC) cells and discussed survivin-related signaling and apoptosis induction. METHODS: Cytotoxicity and apoptosis induced by radiation and/or oxaliplatin were examined in relation to survivin status using two HNSCC cell lines viz., Cal27 and NT8e, and one normal 293-cell line. Survivin gene knockdown by siRNA was also tested in relevance to oxaliplatin-mediated radiosensitization effects. RESULTS: Survivin plays a critical role in mediating radiation-resistance in part through suppression of apoptosis via a caspase-dependent mechanism. Oxaliplatin treatment significantly decreased expression of survivin in cancer cells within 24-72 h. Apoptotic cells and caspase-3 activity were increased parallely with decrease in cell viability, if irradiated during this sensitive period. The cytotoxicity of oxaliplatin and radiation combination was greater than additive. Survivin gene knockdown experiments have demonstrated the role of survivin in radiosensitization of cancer cells mediated by oxaliplatin. CONCLUSIONS: Higher expression of survivin is a critical factor for radioresistance in HNSCC cell lines. Pre-treatment of cancer cells with oxaliplatin significantly increased the radiosensitivity through induction of apoptosis by potently inhibiting survivin.


Assuntos
Antineoplásicos/farmacologia , Regulação para Baixo/efeitos dos fármacos , Neoplasias de Cabeça e Pescoço , Proteínas Associadas aos Microtúbulos/metabolismo , Compostos Organoplatínicos/farmacologia , Tolerância a Radiação , Apoptose/efeitos dos fármacos , Western Blotting , Carcinoma de Células Escamosas , Linhagem Celular Tumoral , Inibidores de Cisteína Proteinase/farmacologia , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Proteínas Inibidoras de Apoptose , Oxaliplatina , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Survivina
16.
Biotechnol Lett ; 32(8): 1019-30, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20401680

RESUMO

The production of biodiesel by transesterification employing acid or base catalyst has been industrially accepted for its high conversion and reaction rates. Downstream processing costs and environmental problems associated with biodiesel production and byproducts recovery have led to the search for alternative production methods. Recently, enzymatic transesterification involving lipases has attracted attention for biodiesel production as it produces high purity product and enables easy separation from the byproduct, glycerol. The use of immobilized lipases and immobilized whole cells may lower the overall cost, while presenting less downstream processing problems, to biodiesel production. The present review gives an overview on biodiesel production technology and analyzes the factors/methods of enzymatic approach reported in the literature and also suggests suitable method on the basis of evidence for industrial production of biodiesel.


Assuntos
Biocombustíveis , Biotecnologia/métodos , Enzimas Imobilizadas , Lipase/metabolismo , Biotecnologia/economia , Biotecnologia/tendências , Catálise , Células Imobilizadas , Esterificação
17.
Head Neck ; 31(8): 1039-48, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19340865

RESUMO

BACKGROUND: Survivin, an inhibitor of apoptosis, is overexpressed in cancer. It has been implicated in both prevention of apoptosis and cell cycle regulation. We investigated the distribution of antiapoptotic protein survivin in 29 oral squamous cell carcinoma (OSCC) and 16 oral premalignant lesions. It has been suggested that wild-type p53 represses survivin expression. Therefore, we investigated the status of p53 in relation to survivin to determine the potential involvement in oral tumorigenesis. METHODS: Oral cancer tissues were freshly obtained at the time of surgery and classified as per general rules of head and neck cancer (TNM classification). Immunohistochemistry and reverse transcriptase-polymerase chain reaction were conducted to study the expression of survivin and p53. The Fisher's exact test was employed to determine the association of survivin and p53 with clinicopathologic parameters of the subjects being studied. RESULTS: Positive staining for survivin was found in 72% OSCC and 44% oral premalignant lesions with no immunoreactions in the corresponding normal tissues. For p53, 59% OSCC, 38% premalignant lesions, and 14% normal tissues were positive. Importantly, about half of the p53-positive OSCC and premalignant tissues also showed survivin positivity (28% OSCC and 18% premalignant lesions). Further, it is observed that the number of survivin positive cells was significantly higher in the p53-positive group. Survivin is expressed in a varying proportion of cells, and in majority of patients it was localized in cytoplasm, whereas p53 is strictly restricted to the nucleus. The survivin expression levels in both primary OSCC and premalignant lesions were significantly higher than in normal oral tissues (OSCC, p < .0008; premalignant lesions, p < .04). No significant correlations between survivin and p53 expression with clinicopathologic parameters were found. CONCLUSIONS: Frequent overexpression of apoptosis regulators, survivin and p53, in OSCC as well as in oral premalignant lesions were found. Overexpression of these 2 markers in premalignant lesions suggest a role in early stages of oral carcinogenesis.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Neoplasias Bucais/genética , Lesões Pré-Cancerosas/genética , Proteína Supressora de Tumor p53/metabolismo , Adulto , Idoso , Biópsia por Agulha , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Estudos de Coortes , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Leucoplasia Oral/genética , Leucoplasia Oral/patologia , Masculino , Proteínas Associadas aos Microtúbulos/genética , Pessoa de Meia-Idade , Neoplasias Bucais/mortalidade , Neoplasias Bucais/patologia , Estadiamento de Neoplasias , Lesões Pré-Cancerosas/patologia , Probabilidade , Prognóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Análise de Sobrevida , Proteína Supressora de Tumor p53/genética , Adulto Jovem
18.
BMC Genet ; 8: 12, 2007 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-17417972

RESUMO

BACKGROUND: India has experienced several waves of migration since the Middle Paleolithic. It is believed that the initial demic movement into India was from Africa along the southern coastal route, approximately 60,000-85,000 years before present (ybp). It has also been reported that there were two other major colonization which included eastward diffusion of Neolithic farmers (Elamo Dravidians) from Middle East sometime between 10,000 and 7,000 ybp and a southern dispersal of Indo Europeans from Central Asia 3,000 ybp. Mongol entry during the thirteenth century A.D. as well as some possible minor incursions from South China 50,000 to 60,000 ybp may have also contributed to cultural, linguistic and genetic diversity in India. Therefore, the genetic affinity and relationship of Indians with other world populations and also within India are often contested. In the present study, we have attempted to offer a fresh and immaculate interpretation on the genetic relationships of different North Indian populations with other Indian and world populations. RESULTS: We have first genotyped 20 tetra-nucleotide STR markers among 1800 north Indian samples of nine endogamous populations belonging to three different socio-cultural strata. Genetic distances (Nei's DA and Reynold's Fst) were calculated among the nine studied populations, Caucasians and East Asians. This analysis was based upon the allelic profile of 20 STR markers to assess the genetic similarity and differences of the north Indian populations. North Indians showed a stronger genetic relationship with the Europeans (DA 0.0341 and Fst 0.0119) as compared to the Asians (DA 0.1694 and Fst - 0.0718). The upper caste Brahmins and Muslims were closest to Caucasians while middle caste populations were closer to Asians. Finally, three phylogenetic assessments based on two different NJ and ML phylogenetic methods and PC plot analysis were carried out using the same panel of 20 STR markers and 20 geo-ethnic populations. The three phylogenetic assessments revealed that north Indians are clustering with Caucasians. CONCLUSION: The genetic affinities of Indians and that of different caste groups towards Caucasians or East Asians is distributed in a cline where geographically north Indians and both upper caste and Muslim populations are genetically closer to the Caucasians.


Assuntos
Consanguinidade , Marcadores Genéticos , Genética Populacional , Adulto , Emigração e Imigração , Etnicidade , Frequência do Gene , Variação Genética , Genótipo , Humanos , Índia , Filogenia
19.
AIDS Res Hum Retroviruses ; 23(1): 153-60, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17263645

RESUMO

p24 is an immunodominant gag core protein of HIV-1. The synthetic immunodominant epitope of p24 and the recombinant p24 show poor immunoreactivity and specificity, respectively. Their application is, therefore, severely limited in the serodiagnosis of HIV-1, although it is an important marker for early diagnosis. These limitations have been overcome by conjugating the synthetic p24 to BSA through a decaalanine peptide spacer. The engineered p24 shows about 5-fold more efficient immunoreactivity than the synthetic p24, and, at the same time, shows a several fold reduction in nonspecific cross-reactivity as compared to recombinant p24. Our strategy to conjugate the p24 peptide epitope to BSA worked well as a consistent and reliable immunodiagnostic marker. This strategy may also prove useful for the diagnosis of other diseases.


Assuntos
Alanina/química , Proteína do Núcleo p24 do HIV/imunologia , HIV-1/imunologia , Peptídeos/química , Soroalbumina Bovina/metabolismo , Reações Cruzadas , Eletroforese em Gel de Poliacrilamida , Epitopos/imunologia , Proteína do Núcleo p24 do HIV/genética , Engenharia de Proteínas , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Sensibilidade e Especificidade
20.
Tuberculosis (Edinb) ; 87(3): 193-201, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17029964

RESUMO

The limitations of the conventional methods for diagnosing tuberculosis have spurred multi-faceted research activities in this field throughout the world. Chromatographic methods appear promising but may not be widely available in the developing countries. Immuno-diagnostic methods using combinations ("cocktails") of antigens have high sensitivity and specificity and can easily be applied in the peripheral laboratories and in the field settings. Though expensive, molecular methods for diagnosis of tuberculosis have advantages of speed, sensitivity, and specificity. Adequate training of the eligible personnels in molecular methods and prevention of laboratory-dependent contamination may help reduce false positive results. Although, there are no clear guidelines, so far on how to make out the best from the gene amplification methods, yet their use may be encouraged with adequate quality controls, because of the inherent ingenuity and promises of these methods. Phage-based molecular methods provide rapid results in susceptibility tests for anti-tubercular drugs. In future, many sophisticated techniques are expected to hit the market for a rapid diagnosis of tuberculosis. In the developing countries, it is necessary to evaluate availability of suitable infrastructure and trained personnels before adopting modern diagnostic methods.


Assuntos
Tuberculose Pulmonar/diagnóstico , Antígenos de Bactérias , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Amplificação de Genes , Humanos , Mycobacterium tuberculosis/imunologia , Mycobacterium tuberculosis/isolamento & purificação , Testes do Emplastro , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Teste Tuberculínico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...