RESUMO
Transfer learning is a machine learning technique that works well with chemical endpoints, with several papers confirming its efficiency. Although effective, because the choice of source/assistant tasks is non-trivial, the application of this technique is severely limited by the domain knowledge of the modeller. Considering this limitation, we developed a purely data-driven approach for source task selection that abstracts the need for domain knowledge. To achieve this, we created a supervised learning setting in which transfer outcome (positive/negative) is the variable to be predicted, and a set of six transferability metrics, calculated based on information from target and source datasets, are the features for prediction. We used the ChEMBL database to generate 100,000 transfers using random pairing, and with these transfers, we trained and evaluated our transferability prediction model (TP-Model). Our TP-Model achieved a 135-fold increase in precision while achieving a sensitivity of 92%, demonstrating a clear superiority against random search. In addition, we observed that transfer learning could provide considerable performance increases when applicable, with an average Matthews Correlation Coefficient (MCC) increase of 0.19 when using a single source and an average MCC increase of 0.44 when using multiple sources.
Assuntos
Aprendizado de Máquina , Relação Quantitativa Estrutura-Atividade , Bases de Dados FactuaisRESUMO
Monoterpenes are non-polar secondary metabolites widely used by industry due to their excellent therapeutic, food-ingredient and cosmetic properties. However, their low solubility in water limits their use. In this sense, cyclodextrins (CDs) have been widely used to solve these technological challenges. Thus, this study aims to use (-)-borneol as a monoterpene model to prepare inclusion complexes between ß-CD and hydroxypropyl-ß-CD (HP-ß-CD) through different ways and characterize them in order to choose the best inclusion method to improve physicochemical properties of monoterpenes. To achieve this goal, the samples were prepared by physical mixture (PM), paste complex (PA) and freeze-drying complex (FD) and then, extensively characterized by thermal analysis, Fourier-transform infrared spectroscopy, scanning electron microscopy, size particle, X-ray diffraction and nuclear magnetic resonance. The physicochemical results showed that freeze-drying was more effective to form inclusion complexes between (-)-borneol with both CDs. This research highlights the importance of recognizing the best method to prepare inclusion complexes, including food additives as (-)-borneol, to achieve better results in food preparations.
Assuntos
Canfanos/química , beta-Ciclodextrinas/química , 2-Hidroxipropil-beta-Ciclodextrina/química , Varredura Diferencial de Calorimetria , Ingredientes de Alimentos , Liofilização/métodos , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Varredura , Monoterpenos/química , Tamanho da Partícula , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Difração de Raios XRESUMO
Liver cancers are one of the leading fatal diseases among malignant neoplasms. Current chemotherapeutic treatments used to fight these illnesses have become less efficient in terms of both efficacy and safety. Therefore, there is a great need of search for new anti-liver cancer agents and this can be accelerated by using computer-aided drug discovery approaches. In this work, we report the development of the first cell-based multi-target model based on quantitative structure-activity relationships (CBMT-QSAR) for the design and prediction of chemicals as anticancer agents against 17 liver cancer cell lines. While having a good quality and predictive power (accuracy higher than 80%) in the training and test sets, respectively, the CBMT-QSAR model was employed as a tool to directly extract suitable fragments from the physicochemical and structural interpretations of the molecular descriptors. Some of these desirable fragments were assembled, leading to the virtual design of eight molecules with drug-like properties, with six of them being predicted as versatile anticancer agents against the 17 liver cancer cell lines reported here.
Assuntos
Antineoplásicos/química , Desenho de Fármacos , Relação Quantitativa Estrutura-Atividade , Animais , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Modelos QuímicosRESUMO
The rupture of the Fundão mine dam in Mariana municipality, Minas Gerais State, Brazil, spilled the tailings across the Doce River basin. These tailings, composed of residues discarded from the beneficiation of iron ore, are rich in SiO and AlO, as well as some ether amine compounds and NaOH. The aim of this study was to assess the distribution of these sediments, as well as their effect on the riparian zones reached, as compared with preserved sites. Sediment deposition in the river resulted in a morphological change from a meandering profile to a braided aspect. The nutrient and mineral content (P, K, Ca, Mg, Cu, Fe, Mn, Zn, and NO) and soil organic matter of the sediments were depleted, whereas NH, Na, and pH increased. A random presence of ether amines in the sediments was confirmed by quantitative and chromatographic analyses, with concentrations ranging from 0 to 57.8 mg kg; Na reached values as high as 150 mg kg. The impact of the dam tailings on biota was assessed by estimating total microbial biomass (phospholipid fatty acids), which were depleted in sediments relative to soils from preserved sites. Overall plant mortality, as well as a low resilience capacity, were also observed. Ether amines and Na present in the sediments had a strong toxic effect in the environment. Identification of these substances as the main impact factors will help guide future remediation efforts.
Assuntos
Vazamento de Resíduos Químicos , Recuperação e Remediação Ambiental/métodos , Resíduos Industriais , Mineração , Brasil , Medição de Risco , Rios/química , Solo/químicaRESUMO
Amides are important natural products which occur in a few plant families. Piplartine and piperine, major amides in Piper tuberculatum and P. nigrum, respectively, have shown a typical N-CO cleavage when analyzed by EI-MS or HRESI-MS. In this study several synthetic analogs of piplartine and piperine were subjected to both types of mass spectrometric analysis in order to identify structural features influencing fragmentation. Most of the amides showed an intense signal of the protonated molecule [M + H]+ when subjected to both HRESI-MS and EI-MS conditions, with a common outcome being the cleavage of the amide bond (N-CO). This results in the loss of the neutral amine or lactam and the formation of aryl acylium cations. The mechanism of N-CO bond cleavage persists in α,ß-unsaturated amides because of the stability caused by extended conjugation. Computational methods determined that the protonation of the piperamides and their derivatives takes place preferentially at the amide nitrogen supporting the dominant the N-CO bond cleavage.
RESUMO
In this study, we designed and synthesized a series of thiophen-2-iminothiazolidine derivatives from thiophen-2-thioureic with good anti-Trypanosoma cruzi activity. Several of the final compounds displayed remarkable trypanocidal activity. The ability of the new compounds to inhibit the activity of the enzyme cruzain, the major cysteine protease of T. cruzi, was also explored. The compounds 3b, 4b, 8b and 8c were the most active derivatives against amastigote form, with significant IC50 values between 9.7 and 6.03µM. The 8c derivative showed the highest potency against cruzain (IC50=2.4µM). Molecular docking study showed that this compound can interact with subsites S1 and S2 simultaneously, and the negative values for the theoretical energy binding (Eb=-7.39kcal·mol(-1)) indicates interaction (via dipole-dipole) between the hybridized sulfur sp(3) atom at the thiazolidine ring and Gly66. Finally, the results suggest that the thiophen-2-iminothiazolidines synthesized are important lead compounds for the continuing battle against Chagas disease.
Assuntos
Tiazolidinas/farmacologia , Tiofenos/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Linhagem Celular , Cisteína Endopeptidases , Inibidores de Cisteína Proteinase/síntese química , Inibidores de Cisteína Proteinase/farmacologia , Inibidores de Cisteína Proteinase/toxicidade , Glicina/química , Camundongos , Simulação de Acoplamento Molecular , Octoxinol , Proteínas de Protozoários/antagonistas & inibidores , Tiazolidinas/síntese química , Tiazolidinas/toxicidade , Tiofenos/síntese química , Tiofenos/toxicidade , Tioureia/análogos & derivados , Tioureia/síntese química , Tioureia/farmacologia , Tioureia/toxicidade , Tripanossomicidas/síntese química , Tripanossomicidas/toxicidadeRESUMO
BACKGROUND: Liver resection is a potentially curative approach for hepatocellular carcinoma (HCC). Laparoscopic liver resections may reduce complication rates, especially in patients with cirrhosis. The aim of this study was to compare the results of laparoscopic liver resection with those of open liver resection for HCC. METHODS: Patients with cirrhosis who underwent minor liver resections for HCC from 2006 to 2013 were identified retrospectively from a prospective database according to the technique adopted (laparoscopic or open). Short- and long-term outcomes were compared between the two groups before and after 1 : 1 propensity score matching. RESULTS: A total of 269 patients were considered: 226 who underwent open liver resection and 43 who had a laparoscopic procedure. The two groups differed at baseline in terms of median age, sex, performance status, tumour location and type of resection. After propensity score matching, two comparable groups of 43 patients each were obtained. Intraoperative bleeding, margin clearance and operative mortality were similar in the two groups, whereas complication rates were lower (49 versus 19 per cent in open versus laparoscopic groups respectively; P = 0·004) and median hospital stay was shorter (8 versus 5 days; P < 0·001) in the laparoscopic group. On multivariable logistic regression analysis, the only independent factor that reduced the risk of postoperative complications was the use of laparoscopy (odds ratio 0·12, 95 per cent c.i. 0·03 to 0·55; P = 0·006). Median overall survival was 57·8 months in the open group and 48·8 months in the laparoscopic group (P = 0·802). Median disease-free survival was 31·7 and 25·5 months respectively (P = 0·990). CONCLUSION: In comparison with the open approach, laparoscopic minor liver resections for HCC improved short-term outcomes, with similar survival results.
Assuntos
Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/cirurgia , Hepatectomia/métodos , Laparoscopia , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/patologia , Intervalo Livre de Doença , Feminino , Humanos , Itália/epidemiologia , Tempo de Internação/estatística & dados numéricos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Pontuação de Propensão , Estudos RetrospectivosRESUMO
Natural products are compounds that are isolated from plants, provide a variety of lead structures for the development of new drugs by the pharmaceutical industry. The interest in these substances increases because of their beneficial effects on human health, which include antiviral, antiallergic, antiplatelet, anti-inflammatory, antitumor, antioxidant, and antiparasitic activities. Leishmaniasis is the infection caused by protozoa of the genus Leishmania, which affects mainly people who live in poor countries, and can cause chronic fever, liver problems, anemia, and other blood problems. Current chemotherapies against the disease cause side effects, and are ineffective. There are no vaccines, and new chemotherapeutic agents for the treatment of leishmaniasis are greatly needed. This work reports on some of the enzymatic targets studied in the development of new drugs using natural products as inhibitors for the treatment of leishmaniasis. We applied ligand-based-virtual screening using Random Forest, associated with structure-based-virtual screening (docking), of a small dataset of 683 flavonoids and derivatives from an in-house data bank to select structures with potential inhibitory activity against pyruvate kinase, an important enzyme in Leishmania mexicana's energy production chemistry. The computer-aided drug design studies revealed good results against Leishmaniasis for flavones.
Assuntos
Produtos Biológicos/química , Inibidores Enzimáticos/química , Leishmania/enzimologia , Aciltransferases/antagonistas & inibidores , Aciltransferases/metabolismo , Adenina Fosforribosiltransferase/antagonistas & inibidores , Adenina Fosforribosiltransferase/metabolismo , Área Sob a Curva , Arginase/antagonistas & inibidores , Arginase/metabolismo , Sítios de Ligação , Produtos Biológicos/metabolismo , Produtos Biológicos/farmacologia , Desenho Assistido por Computador , Di-Hidro-Orotato Desidrogenase , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Humanos , Leishmania/efeitos dos fármacos , Simulação de Acoplamento Molecular , Oxirredutases/antagonistas & inibidores , Oxirredutases/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Peptidilprolil Isomerase/antagonistas & inibidores , Peptidilprolil Isomerase/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/metabolismo , Curva ROCRESUMO
Benzodiazepines (BZ or BZD) are a class of gabaminergic psychoactive chemicals used in hypnotics, sedation, in the treatment of anxiety, and in other CNS disorders. These drugs include alprazolam (Xanax), diazepam (Valium), clonazepam (Klonopin), and others. There are two distinct types of pharmacological binding sites for benzodiazepines in the brain (BZ1 and BZ2), these sites are on GABA-A receptors, and are classified as short, intermediate, or long-acting. From the thienobenzodiazepine class (TBZ), Olanzapine (2-methyl-4-(4-methyl-l-piperazinyl)-10H-thieno[2,3-b][1,5]benzodiazepine) (Zyprexa) was used as an example to demonstrate the antagonism of this class of compounds for multiples receptors including: dopamine D1-D5, α-adrenoreceptor, histamine H1, muscarinic M1-M5 and 5-HT2A, 5-HT2B, 5-HT2C, 5-HT3 and 5-HT6 receptors. Olanzapine is an atypical antipsychotic agent, structurally related to clozapine, and extensively used for the treatment of schizophrenia, bipolar disorder-associated mania, and the behavioral symptoms of Alzheimer's disease. The functional blockade of these multiple receptors contributes to the wide range of its pharmacologic and therapeutic activities, having relatively few side effects when compared to other antipsychotics agents. Thienobenzodiazepines (such as Olanzapine) are characterized as multi- receptor- targeted- acting- agents. This mini-review discusses these 2 drug classes that act on the central nervous system, the main active compounds used, and the various receptors with which they interact. In addition, we propose 12 olanzapine analogues, and generated Random Forest models, from a data set obtained from the ChEMBL database, to classify the structures as active or inactive against 5 dopamine receptors (D1, D2, D3, D4, D5 and D6), and dopamine transporter.
Assuntos
Antipsicóticos/química , Antipsicóticos/farmacologia , Benzodiazepinas/química , Benzodiazepinas/farmacologia , Sistema Nervoso Central/efeitos dos fármacos , Terapia de Alvo Molecular , Polifarmacologia , Animais , Antipsicóticos/uso terapêutico , Benzodiazepinas/uso terapêutico , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/patologia , Doenças do Sistema Nervoso Central/tratamento farmacológico , Doenças do Sistema Nervoso Central/metabolismo , Humanos , Terapia de Alvo Molecular/métodos , Olanzapina , Receptores Adrenérgicos alfa/metabolismo , Receptores Dopaminérgicos/metabolismo , Receptores Histamínicos H1/metabolismo , Receptores Muscarínicos/metabolismo , Inibidores Seletivos de Recaptação de Serotonina/química , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Ácido gama-Aminobutírico/metabolismoRESUMO
Infections with protozoan parasites are a major cause of disease and mortality in many tropical countries of the world. Diseases caused by species of the genera Trypanosoma (Human African Trypanosomiasis and Chagas Disease) and Leishmania (various forms of Leishmaniasis) are among the seventeen "Neglected Tropical Diseases" (NTDs) defined by the WHO. Furthermore, malaria (caused by various Plasmodium species) can be considered a neglected disease in certain countries and with regard to availability and affordability of the antimalarials. Living organisms, especially plants, provide an innumerable number of molecules with potential for the treatment of many serious diseases. The current review attempts to give an overview on the potential of such plant-derived natural products as antiprotozoal leads and/or drugs in the fight against NTDs. In part I, a general description of the diseases, the current state of therapy and need for new therapeuticals, assay methods and strategies applied in the search for new plant derived natural products against these diseases and an overview on natural products of terpenoid origin with antiprotozoal potential were given. The present part II compiles the current knowledge on natural products with antiprotozoal activity that are derived from the shikimate pathway (lignans, coumarins, caffeic acid derivatives), quinones of various structural classes, compounds formed via the polyketide pathways (flavonoids and related compounds, chromenes and related benzopyrans and benzofurans, xanthones, acetogenins from Annonaceae and polyacetylenes) as well as the diverse classes of alkaloids. In total, both parts compile the literature on almost 900 different plant-derived natural products and their activity data, taken from over 800 references. These data, as the result of enormous efforts of numerous research groups world-wide, illustrate that plant secondary metabolites represent an immensely rich source of chemical diversity with an extremely high potential to yield a wealth of lead structures towards new therapies for NTDs. Only a small percentage, however, of the roughly 200,000 plant species on earth have been studied chemically and only a small percentage of these plants or their constituents has been investigated for antiprotozoal activity. The repository of plant-derived natural products hence deserves to be investigated even more intensely than it has been up to present.
Assuntos
Antiprotozoários/uso terapêutico , Produtos Biológicos/uso terapêutico , Doenças Negligenciadas/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Plantas Medicinais/química , Infecções por Protozoários/tratamento farmacológico , Animais , Antiprotozoários/química , Antiprotozoários/metabolismo , Produtos Biológicos/química , Produtos Biológicos/metabolismo , Humanos , Fitoterapia , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Plantas Medicinais/metabolismoRESUMO
Infections with protozoan parasites are a major cause of disease and mortality in many tropical countries of the world. Diseases caused by species of the genera Trypanosoma (Human African Trypanosomiasis and Chagas Disease) and Leishmania (various forms of Leishmaniasis) are among the seventeen "Neglected Tropical Diseases" (NTDs) defined as such by WHO due to the neglect of financial investment into research and development of new drugs by a large part of pharmaceutical industry and neglect of public awareness in high income countries. Another major tropical protozoan disease is malaria (caused by various Plasmodium species), which -although not mentioned currently by the WHO as a neglected disease- still represents a major problem, especially to people living under poor circumstances in tropical countries. Malaria causes by far the highest number of deaths of all protozoan infections and is often (as in this review) included in the NTDs. The mentioned diseases threaten many millions of lives world-wide and they are mostly associated with poor socioeconomic and hygienic environment. Existing therapies suffer from various shortcomings, namely, a high degree of toxicity and unwanted effects, lack of availability and/or problematic application under the life conditions of affected populations. Development of new, safe and affordable drugs is therefore an urgent need. Nature has provided an innumerable number of drugs for the treatment of many serious diseases. Among the natural sources for new bioactive chemicals, plants are still predominant. Their secondary metabolism yields an immeasurable wealth of chemical structures which has been and will continue to be a source of new drugs, directly in their native form and after optimization by synthetic medicinal chemistry. The current review, published in two parts, attempts to give an overview on the potential of such plant-derived natural products as antiprotozoal leads and/or drugs in the fight against NTDs.
Assuntos
Antiprotozoários/uso terapêutico , Produtos Biológicos/uso terapêutico , Doenças Negligenciadas/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Plantas Medicinais/química , Plantas Medicinais/metabolismo , Infecções por Protozoários/tratamento farmacológico , Animais , Antiprotozoários/química , Antiprotozoários/metabolismo , Produtos Biológicos/química , Produtos Biológicos/metabolismo , Humanos , Fitoterapia , Extratos Vegetais/química , Extratos Vegetais/metabolismoRESUMO
Infections with protozoan parasites are a major cause of disease and mortality in many tropical countries of the world. Diseases caused by species of the genera Trypanosoma (Human African Trypanosomiasis and Chagas Disease) and Leishmania (various forms of Leishmaniasis) are among the seventeen "Neglected Tropical Diseases" (NTDs) defined as such by WHO due to the neglect of financial investment into research and development of new drugs by a large part of pharmaceutical industry and neglect of public awareness in high income countries. Another major tropical protozoan disease is malaria (caused by various Plasmodium species), which -although not mentioned currently by the WHO as a neglected disease- still represents a major problem, especially to people living under poor circumstances in tropical countries. Malaria causes by far the highest number of deaths of all protozoan infections and is often (as in this review) included in the NTDs. The mentioned diseases threaten many millions of lives world-wide and they are mostly associated with poor socioeconomic and hygienic environment. Existing therapies suffer from various shortcomings, namely, a high degree of toxicity and unwanted effects, lack of availability and/or problematic application under the life conditions of affected populations. Development of new, safe and affordable drugs is therefore an urgent need. Nature has provided an innumerable number of drugs for the treatment of many serious diseases. Among the natural sources for new bioactive chemicals, plants are still predominant. Their secondary metabolism yields an immeasurable wealth of chemical structures which has been and will continue to be a source of new drugs, directly in their native form and after optimization by synthetic medicinal chemistry. The current review, published in two parts, attempts to give an overview on the potential of such plant-derived natural products as antiprotozoal leads and/or drugs in the fight against NTDs.
Assuntos
Plantas Medicinais/metabolismo , Plantas Medicinais/química , Infecções por Protozoários/tratamento farmacológico , Produtos Biológicos/metabolismo , Produtos Biológicos/uso terapêutico , Produtos Biológicos/química , Humanos , Extratos Vegetais/metabolismo , Extratos Vegetais/uso terapêutico , Extratos Vegetais/química , Animais , Fitoterapia , Antiprotozoários/metabolismo , Antiprotozoários/uso terapêutico , Antiprotozoários/químicaRESUMO
Encapsidation of cellular- or plasmid-derived DNA sequences during recombinant adeno-associated virus (rAAV) production has been well documented. However, most of the published data were generated from rAAV vectors manufactured by the plasmid transient transfection method. We previously reported a novel, scalable method for rAAV manufacturing based on a recombinant herpes simplex virus (rHSV) complementation system. In this report, we evaluated clearance of DNA impurities during rAAV purification, by determining the quantity of residual herpes simplex virus and cellular DNA at each process step. A single Benzonase treatment during the upstream process effectively reduced unprotected HSV and cellular DNA to <300 bp fragments, and subsequent chromatography steps completely removed these small DNA fragments. Further analysis showed that trace amounts of residual, DNase-resistant HSV and cellular DNA were present at static concentrations during subsequent purification steps, and the residual HSV DNA sequences were single stranded, ranging from 0.8 to 4.2 kb. After transduction of human embryonic kidney 293 cells with purified rAAV, the residual HSV DNA fragments were neither transcribed nor translated into HSV proteins. In summary, this manufacturing process for rAAV production was effective in removing DNA and protein contaminants and achieving a highly purified product, suitable for human clinical application.
Assuntos
DNA Viral/análise , Dependovirus/genética , Vetores Genéticos , Recombinação Genética , Simplexvirus/genética , Animais , Linhagem Celular , Cricetinae , Dependovirus/isolamento & purificação , Endodesoxirribonucleases/farmacologia , Endorribonucleases/farmacologia , Técnicas de Transferência de Genes , Células HEK293 , Humanos , Transdução GenéticaRESUMO
Recombinant herpes simplex virus type 1 (rHSV)-assisted recombinant adeno-associated virus (rAAV) vector production provides a highly efficient and scalable method for manufacture of clinical grade rAAV vectors. Here, we present an rHSV co-infection system for rAAV production, which uses two ICP27-deficient rHSV constructs, one bearing the rep2 and cap (1, 2 or 9) genes of rAAV, and the second bearing an AAV2 ITR-gene of interest (GOI) cassette. The optimum rAAV production parameters were defined by producing rAAV2/GFP in HEK293 cells, yielding greater than 9000 infectious particles per cell with a 14:1 DNase resistance particle to infectious particle (DRP/ip) ratio. The optimized co-infection parameters were then used to generate large-scale stocks of rAAV1/AAT, which encode the human alpha-1-antitrypsin (hAAT) protein, and purified by column chromatography. The purified vector was extensively characterized by rAAV- and rHSV-specific assays and compared to transfection-made vector for in vivo efficacy in mice through intramuscular injection. The co-infection method was also used to produce rAAV9/AAT for comparison to rAAV1/AAT in vivo. Intramuscular administration of 1 x 10(11) DRP per animal of rHSV-produced rAAV1/AAT and rAAV9/AAT resulted in hAAT protein expression of 5.4 x 10(4) and 9.4 x 10(5) ng ml(-1) serum respectively, the latter being clinically relevant.
Assuntos
Dependovirus/genética , Vetores Genéticos/biossíntese , Herpesvirus Humano 1/genética , Animais , Western Blotting , Linhagem Celular , Técnicas de Transferência de Genes , Vetores Genéticos/isolamento & purificação , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Recombinação Genética , Transfecção , Cultura de Vírus/métodos , alfa 1-Antitripsina/biossínteseRESUMO
Kisspeptin, a neuropeptide product of the KiSS-1 gene, has recently been implicated in the regulation of seasonal breeding in a number of species, including Siberian hamsters. In this species, kisspeptin expression is reduced in the anteroventral periventricular nucleus (AVPV) following exposure to inhibitory day lengths, and exogenous kisspeptin activates the reproductive neuroendocrine axis of reproductively quiescent animals. Because sex steroids can impact kisspeptin expression, it is unclear whether changes in kisspeptin occur in direct response to photoperiodic cues or secondarily in response to changes in sex steroid concentrations resulting from the transition to reproductive quiescence. The present study aimed to assess the relative contributions of photoperiod and testosterone in regulating kisspeptin expression in Siberian hamsters. Animals housed in long or short day lengths for 8 weeks were either castrated or received sham surgeries. Half of the hamsters in each photoperiod were given testosterone to mimic long-day sex steroid concentrations. The results obtained indicate that kisspeptin neurones in the AVPV and arcuate nuclei were influenced by both photoperiod and testosterone. In the AVPV, removal of testosterone or exposure to inhibitory day lengths led to a marked reduction in kisspeptin-immunoreactive cells, and testosterone treatment increased cell numbers across conditions. Importantly, long-day castrates exhibited significantly more kisspeptin cells than short-day castrates or intact short-day animals with empty capsules, suggesting the influences of photoperiod, independent of gonadal steroids. In general, the opposite pattern emerged for the arcuate nuclei. Collectively, these data suggest a role for both gonadal-dependent and independent (i.e. photoperiodic) mechanisms regulating seasonal changes in kisspeptin expression in Siberian hamsters.
Assuntos
Phodopus/fisiologia , Fotoperíodo , Estações do Ano , Testosterona/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Cricetinae , Feminino , Expressão Gênica , Hipotálamo/anatomia & histologia , Hipotálamo/metabolismo , Masculino , Orquiectomia , Comportamento Sexual Animal/fisiologia , Proteínas Supressoras de Tumor/genéticaRESUMO
BACKGROUND: The treatment of pancreatic cancer is still rudimentary, even in the case of locally limited tumors, because of the high frequency of recurrence due to severe suppression of the anticancer immunity that is further amplified by surgery-induced immunosuppression, evidenced by a decline in lymphocyte numbers during the postoperative period. Previous studies in colorectal cancer demonstrated that surgery-induced lymphocytopenia may be abrogated by a brief preoperative administration of IL-2. MATERIALS AND METHODS: The study included 30 consecutive patients who were randomized to be treated by radical surgery alone as a control group or by a preoperative immunotherapy with IL-2 (12 MIU/day SC for 3 consecutive days) plus surgery. RESULTS: Mean lymphocyte numbers significantly decreased in patients treated with surgery only, whereas it significantly rose in the IL-2-treated group. After a follow-up of 36 months, both the free-from-progression period (FFPP) and the overall survival were significantly higher in patients treated with IL-2. CONCLUSION: These preliminary results suggest that a short-period preoperative immunotherapy with IL-2 is sufficient to modify host tumor interactions in operable pancreatic cancer, with a subsequent abrogation of postoperative lymphocytopenia and a prolongation of FFPP and overall survival time.
Assuntos
Interleucina-2/uso terapêutico , Neoplasias Pancreáticas/terapia , Idoso , Terapia Combinada , Intervalo Livre de Doença , Feminino , Humanos , Imunoterapia/métodos , Interleucina-2/imunologia , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/cirurgia , Taxa de SobrevidaRESUMO
The cancer stem cell hypothesis posits that tumors are derived from a single cancer-initiating cell with stem cell properties. The task of identifying and characterizing a single cancer-initiating cell with stem cell properties has proven technically difficult because of the scarcity of the cancer stem cells in the tissue of origin and the lack of specific markers for cancer stem cells. Here we show that a single LA7 cell derived from rat mammary adenocarcinoma has the following properties: the differentiation potential to generate all of the cell lineages of the mammary gland; the ability to generate branched duct-like structures that recapitulate morphologically and functionally the ductal-alveolar-like architecture of the mammary tree; and the capacity to initiate heterogeneous tumors in nonobese diabetic-SCID mice. In addition, we show that cultured cells derived from tumors generated by a single LA7 cell-injection have properties similar to LA7 cells, can generate all of the cell lineages of the mammary gland, and recapitulate the ductal-alveolar-like architecture of the mammary tree. The properties of self-renewal, extensive capacity for proliferation, multilineage differentiation potential, and single-cell tumor-initiation potential suggest that LA7 cells are cancer stem cells and can be used as a model system to study the dynamics of tumor formation at the single-cell level.
Assuntos
Diferenciação Celular , Proliferação de Células , Células-Tronco Neoplásicas/patologia , Adenocarcinoma/patologia , Animais , Benzimidazóis/metabolismo , Neoplasias da Mama/patologia , Carbazóis/metabolismo , Linhagem Celular Tumoral , Linhagem da Célula , Células Cultivadas , Células Clonais , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Corantes Fluorescentes/metabolismo , Imuno-Histoquímica , Queratina-14/metabolismo , Queratina-18/metabolismo , Glândulas Mamárias Animais/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Células-Tronco Neoplásicas/metabolismo , Técnicas de Cultura de Órgãos , Ratos , Transplante de Células-Tronco , Transplante HeterólogoRESUMO
Expression profiles of breast carcinomas are difficult to interpret when they are obtained from tissue in toto, which may contain a large proportion of non-cancer cells. To avoid this problem, we microscopically isolated cells from a primary invasive ductal carcinoma of the breast and from an axillary node harboring a metastatic breast carcinoma, to obtain pure populations of carcinoma cells ( approximately 500) and used them for serial analysis of gene expression. The expression profiles generated from both populations of cells were compared with the profile of a disease-free mammary epithelium. We showed that the expression profiles obtained are exclusive of carcinoma cells with no contribution of non-epithelial cells. From a total of 16,939 unique tags analyzed, we detected 559 statistically significant changes in gene expression; some of these genes have not been previously associated with breast cancer. We observed that many of the down-regulated genes are the same in both cancers, whereas the up-regulated genes are completely different, suggesting that the down-regulation of a set of genes may be the basic mechanism of cancer formation, while the up-regulation may characterize and possibly control the state of evolution of individual cancers. The results obtained may help in characterizing the neoplastic process of breast cancer.
Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinoma/patologia , Células Epiteliais/metabolismo , Regulação Neoplásica da Expressão Gênica , Metástase Linfática , Mama/metabolismo , Carcinoma/genética , DNA Complementar/metabolismo , Regulação para Baixo , Epitélio/metabolismo , Biblioteca Gênica , Humanos , Hibridização In Situ , Regulação para CimaRESUMO
Cell-mediated immunodeficiency, with Total and T lymphocytes count decrease, is well established in cancer patients and it predicts a poor prognosis and poor survival rates. Furthermore, major surgery induces a transient immunodeficiency, too. Nevertheless, cell-mediated immunity in pancreatic cancer, which has a very poor prognosis, has not been completely outlined. Aim of this study is to evaluate the cell-mediated IL-2 dependent immune status in operable pancreatic cancer patients and to compare it with other gastrointestinal tumors. One hundred and twenty-one cancer patients (22 pancreatic, 48 gastric and 51 colorectal), with a median age of 66 years (range 42-83), 55 males and 66 females, were enrolled. Total lymphocyte count and lymphocytes subset (T helper count - CD4+) were assessed preoperatively and on the 14th and 50th postoperative day. Results obtained were compared between the groups and related to nodal involvement (N0 versus N+). Colorectal and gastric cancer patients showed quantitative lymphocyte deficiency at baseline in 29% and 41% of cases, respectively. Fourteen days after surgery values below normal range were found in 44% and 54% (Total) and 53% and 67% (T helper), respectively. Recovery of postoperative surgery-related lymphocytopenia occurred late only in patients with normal count at baseline. According to regional nodal involvement (pN0/N+) T helper deficiency was significantly more frequent in patients with nodal involvement than in patients without. In pancreatic cancer, percentage of immunodepressed patients at baseline was higher compared to the other two groups (71%). Lymphocyte count was significantly different between pancreatic and gastric/colorectal cancer, reaching a statistical significance at baseline and on the 14th and 50th postoperative day. No differences of T helper deficiency were noted according to nodal involvement (N0 versus N+) neither at baseline nor in the postoperative period. In conclusion, the degree of immunosuppression varies among different tumor types: since initial stages of disease, immunodepression was significantly greater in pancreatic cancer which should be considered always a systemic disease even in early stages and indipendently from the nodal involvement and from tumor load.
Assuntos
Adenocarcinoma/imunologia , Neoplasias Gastrointestinais/imunologia , Síndromes de Imunodeficiência/imunologia , Neoplasias Pancreáticas/imunologia , Adenocarcinoma/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Linfócitos T CD4-Positivos/metabolismo , Feminino , Neoplasias Gastrointestinais/cirurgia , Humanos , Imunidade Celular , Interleucina-2/farmacologia , Linfonodos/imunologia , Linfonodos/patologia , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/cirurgia , Complicações Pós-Operatórias , Estudos ProspectivosRESUMO
We previously identified rat8 in the pathway involved in epithelial cell differentiation that occurs in the rat mammary gland at pregnancy when tubules and alveoli are formed. rat8, which encodes an IFN-inducible membrane protein, is the rat homologue of the mouse gene fragilis. By differential detergent extraction and isopycnic sucrose density gradients, we show that rat8 protein is associated to lipid membrane domains together with Lyn and Fyn, members of the Src tyrosine kinase family. We also show that recruitment of rat8 to lipid membrane domains is a necessary step in mammary epithelial cell differentiation. Immunoprecipitation analysis, performed with an anti-Fyn protein antibody, shows that rat8 was present in the Fyn immunoprecipitate. Antisense oligonucleotides, used to inhibit Fyn protein expression, block mammary cell differentiation. Taken together, these results suggest that the functional interaction, via lipid membrane domains, of rat8 and Fyn proteins is required for mammary cell differentiation. Therefore, rat8, like fragilis, may be involved in developmental decisions and the demarcation of a subset of cells in the mammary gland that cause epithelial cells to develop into a network of tubuloalveolar structures involved in secretion.