RESUMO
The untranslated regions (UTRs) of viral genomes contain a variety of conserved yet dynamic structures crucial for viral replication, providing drug targets for the development of broad spectrum anti-virals. We combine in vitro RNA analysis with molecular dynamics simulations to build the first 3D models of the structure and dynamics of key regions of the 5' UTR of the SARS-CoV-2 genome. Furthermore, we determine the binding of metallo-supramolecular helicates (cylinders) to this RNA structure. These nano-size agents are uniquely able to thread through RNA junctions and we identify their binding to a 3-base bulge and the central cross 4-way junction located in stem loop 5. Finally, we show these RNA-binding cylinders suppress SARS-CoV-2 replication, highlighting their potential as novel anti-viral agents.
Assuntos
Regiões 5' não Traduzidas , Antivirais/farmacologia , Substâncias Macromoleculares/farmacologia , RNA/metabolismo , SARS-CoV-2/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Animais , Antivirais/química , Antivirais/metabolismo , Chlorocebus aethiops , Complexos de Coordenação/química , Complexos de Coordenação/metabolismo , Complexos de Coordenação/farmacologia , Genoma Viral/efeitos dos fármacos , Substâncias Macromoleculares/química , Substâncias Macromoleculares/metabolismo , Metais Pesados/química , Simulação de Dinâmica Molecular , RNA/genética , SARS-CoV-2/química , Células VeroRESUMO
A class of rotaxane is created, not by encapsulating a conventional linear thread, but rather by wrapping a large cucurbit[10]uril macrocycle about a three-dimensional, cylindrical, nanosized, self-assembled supramolecular helicate as the axle. The resulting pseudo-rotaxane is readily converted into a proper interlocked rotaxane by adding branch points to the helicate strands that form the surface of the cylinder (like branches and roots on a tree trunk). The supramolecular cylinder that forms the axle is itself a member of a unique and remarkable class of helicate metallo-drugs that bind Y-shaped DNA junction structures and induce cell death. While pseudo-rotaxanation does not modify the DNA-binding properties, proper, mechanically-interlocked rotaxanation transforms the DNA-binding and biological activity of the cylinder. The ability of the cylinder to de-thread from the rotaxane (and thus to bind DNA junction structures) is controlled by the extent of branching: fully-branched cylinders are locked inside the cucurbit[10]uril macrocycle, while cylinders with incomplete branch points can de-thread from the rotaxane in response to competitor guests. The number of branch points can thus afford kinetic control over the drug de-threading and release.
Assuntos
DNA/química , Metais/química , Nanoestruturas/química , Rotaxanos/química , Hidrocarbonetos Aromáticos com Pontes/química , Complexos de Coordenação/química , Imidazóis/química , LigantesRESUMO
Population genetic analyses of bacterial genes whose products interact with host tissues can give new understanding of infection and disease processes. Here we show that strains of the genetically diverse gastric pathogen Helicobacter pylori from Amerindians from the remote Peruvian Amazon contain novel alleles of cagA, a major virulence gene, and reveal distinctive properties of their encoded CagA proteins. CagA is injected into the gastric epithelium where it hijacks pleiotropic signaling pathways, helps Hp exploit its special gastric mucosal niche, and affects the risk that infection will result in overt gastroduodenal diseases including gastric cancer. The Amerindian CagA proteins contain unusual but functional tyrosine phosphorylation motifs and attenuated CRPIA motifs, which affect gastric epithelial proliferation, inflammation, and bacterial pathogenesis. Amerindian CagA proteins induced less production of IL-8 and cancer-associated Mucin 2 than did those of prototype Western or East Asian strains and behaved as dominant negative inhibitors of action of prototype CagA during mixed infection of Mongolian gerbils. We suggest that Amerindian cagA is of relatively low virulence, that this may have been selected in ancestral strains during infection of the people who migrated from Asia into the Americas many thousands of years ago, and that such attenuated CagA proteins could be useful therapeutically.
Assuntos
Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Evolução Molecular , Infecções por Helicobacter/metabolismo , Helicobacter pylori/metabolismo , Helicobacter pylori/patogenicidade , Fatores de Virulência/metabolismo , Alelos , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Feminino , Mucosa Gástrica/metabolismo , Mucosa Gástrica/microbiologia , Gerbillinae , Infecções por Helicobacter/genética , Helicobacter pylori/genética , Humanos , Indígenas Sul-Americanos , Interleucina-8/genética , Interleucina-8/metabolismo , Masculino , Dados de Sequência Molecular , Mucina-2/genética , Mucina-2/metabolismo , Peru , Fosforilação , Transdução de Sinais/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/microbiologia , Fatores de Virulência/genéticaRESUMO
The untranslated regions (UTRs) of viral genomes contain a variety of conserved yet dynamic structures crucial for viral replication, providing drug targets for the development of broad spectrum anti-virals. We combine in vitro RNA analysis with molecular dynamics simulations to build the first 3D models of the structure and dynamics of key regions of the 5' UTR of the SARS-CoV-2 genome. Furthermore, we determine the binding of metallo-supramolecular helicates (cylinders) to this RNA structure. These nano-size agents are uniquely able to thread through RNA junctions and we identify their binding to a 3-base bulge and the central cross 4-way junction located in stem loop 5. Finally, we show these RNA-binding cylinders suppress SARS-CoV-2 replication, highlighting their potential as novel anti-viral agents.
RESUMO
Region-specific Helicobacter pylori subpopulations have been identified. It is proposed that the hspAmerind subpopulation is being displaced from the Americans by an hpEurope population following the conquest. Our study aimed to describe the genomes and methylomes of H. pylori isolates from distinct Peruvian communities: 23 strains collected from three groups of Native Americans (Asháninkas [ASHA, n = 9], Shimaas [SHIM, n = 5] from Amazonas, and Punos from the Andean highlands [PUNO, n = 9]) and 9 modern mestizos from Lima (LIM). Closed genomes and DNA modification calls were obtained using SMRT/PacBio sequencing. We performed evolutionary analyses and evaluated genomic/epigenomic differences among strain groups. We also evaluated human genome-wide data from 74 individuals from the selected Native communities (including the 23 H. pylori strains donors) to compare host and bacterial backgrounds. There were varying degrees of hspAmerind ancestry in all strains, ranging from 7% in LIM to 99% in SHIM. We identified three H. pylori subpopulations corresponding to each of the Native groups and a novel hspEuropePeru which evolved in the modern mestizos. The divergence of the indigenous H. pylori strains recapitulated the genetic structure of Native Americans. Phylogenetic profiling showed that Orthogroups in the indigenous strains seem to have evolved differentially toward epigenomic regulation and chromosome maintenance, whereas OGs in the modern mestizo (LIM) seem to have evolved toward virulence and adherence. The prevalence of cagA +/vacA s1i1m1 genotype was similar across populations (p = 0.32): 89% in ASHA, 67% in PUNO, 56% in LIM and 40% in SHIM. Both cagA and vacA sequences showed that LIM strains were genetically differentiated (p < 0.001) as compared to indigenous strains. We identified 642 R-M systems with 39% of the associated genes located in the core genome. We found 692 methylation motifs, including 254 population-specific sequences not previously described. In Peru, hspAmerind is not extinct, with traces found even in a heavily admixed mestizo population. Notably, our study identified three new hspAmerind subpopulations, one per Native group; and a new subpopulation among mestizos that we named hspEuropePeru. This subpopulation seems to have more virulence-related elements than hspAmerind. Purifying selection driven by variable host immune response may have shaped the evolution of Peruvian subpopulations, potentially impacting disease outcomes.
RESUMO
PURPOSE: This study is to document the activity and acceptability for a new topical agent, A-007, in the treatment of cutaneous metastases from cancer. PATIENTS AND METHODS: This is a multicenter study involving 27 patients with inoperable skin lesions from histologically confirmed cancers of the breast and oral cavity, non-Hodgkin's lymphoma, Kaposi's sarcoma, and angiosarcoma that had failed radiotherapy or systemic treatment. A-007, as a 0.25% gel, was applied twice daily to the areas of cancer to be measured as well as applied to a healthy control area distant from the cancer areas. An untreated cancer area was also included and documented as a cancer control. RESULTS: The overall objected response rate with A-007 was 26%, with an additional 19% minimum response/stabilization of cancer. For patients with breast cancer, hormonal status did not have an impact on response. The median duration of response was 15 weeks (with one patient having a response for 3.5 years). Toxicities observed were itching, burning, and a rash, in 6 of the 27 patients. The skin toxicities were in the cancer-treated fields; none were observed in the A-007 control areas. All irritated areas cleared while continuing treatment, and the tumor lesions in the areas of itching also improved. CONCLUSION: A-007, as a 0.25% gel, is confirmed as an effective palliative treatment option for cutaneous metastases from cancers. Skin reactions were minimal, tolerated, and no cessation of treatment was required.
Assuntos
Antineoplásicos/uso terapêutico , Hidrazonas/uso terapêutico , Fenóis/uso terapêutico , Neoplasias Cutâneas/tratamento farmacológico , Administração Tópica , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacocinética , Feminino , Humanos , Hidrazonas/efeitos adversos , Hidrazonas/farmacocinética , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Fenóis/efeitos adversos , Fenóis/farmacocinética , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/secundárioRESUMO
The purpose of this article is to share one institution's intervention to improve oral chemotherapy patient education. The overall aim was to provide clinicians with a single source of educational materials that would meet a diverse group of patients' educational needs and be consistent with published guidelines.â©.
Assuntos
Antineoplásicos/administração & dosagem , Neoplasias/tratamento farmacológico , Educação de Pacientes como Assunto/métodos , Materiais de Ensino/provisão & distribuição , Acesso à Informação , Administração Oral , Antineoplásicos/efeitos adversos , CD-ROM , Feminino , Humanos , Masculino , Gestão da Qualidade Total , Estados UnidosRESUMO
[reaction: see text]. Oxazolidinone-functionalized enecarbamates show contrasting behavior upon oxidation by singlet oxygen and by ozone. The observed stereoselectivity difference indicates that the oxidation with ozone is subject to classic steric effects, whereas the very high selectivity in the photooxidation with singlet oxygen is derived from vibrational deactivation.
RESUMO
PURPOSE/OBJECTIVES: To evaluate a nurse-led intervention to enhance medication knowledge and adherence using the Multinational Association for Supportive Care in Cancer Oral Agent Teaching Tool (MOATT). DESIGN: Longitudinal, descriptive feasibility study. SETTING: An ambulatory thoracic oncology disease center located at the Dana-Farber Cancer Institute in Boston, MA. SAMPLE: 30 adult patients with lung cancer who received the oral agent erlotinib. METHODS: Structured, nurse-led education sessions using the MOATT were provided, with a 72-hour follow-up telephone contact. Participants completed a Knowledge Rating Scale (KRS) and adapted Morisky Medication Adherence Scale-8 (MMAS-8) at the end of the first cycle of oral chemotherapy. MAIN RESEARCH VARIABLES: Knowledge and adherence; feasibility. FINDINGS: Twenty-seven participants completed the study outcome measures reporting high knowledge levels and MMAS-8 scores. Structured, nurse-led education and follow-up monitoring sessions ranged from 14-30 minutes. Several participants also initiated contact for assistance with prescription procurement and symptom management. Participants reported a median of two side effects. CONCLUSIONS: The structured, nurse-led teaching, using the MOATT tool, and follow-up nurse contacts were feasible as integrated into the thoracic oncology setting. Adherence and knowledge outcomes were encouraging. Additional studies should include objective adherence measures and strategies for delivering supportive care to patients at home. IMPLICATIONS FOR NURSING: Structured teaching with patients is important to enhance proper oral anticancer medication knowledge and adherence, including follow-up monitoring of administration and side effects at 72 hours.
Assuntos
Antineoplásicos/administração & dosagem , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/enfermagem , Cloridrato de Erlotinib/administração & dosagem , Adesão à Medicação , Papel do Profissional de Enfermagem , Educação de Pacientes como Assunto/organização & administração , Administração Oral , Adulto , Idoso , Boston , Estudos de Viabilidade , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Relações Enfermeiro-Paciente , Enfermagem Oncológica/métodos , Projetos Piloto , Inquéritos e QuestionáriosRESUMO
4,4'-dihydroxybenzophenone-2,4-dinitrophenylhydrazone (A-007) has recently completed a phase I clinical trial in advanced cancer with minimal toxicity, and impressive objective responses were noted. A-007 possesses three moieties that appear to have an influence on its anticancer activities: diphenylmethane, hydrazone, and dinitrophenyl. The goals of this study were to modify A-007's chemical moieties with the ultimate goal of maximizing its anticancer activity through increased planarity and introduction of functional groups. Thirty-five phenylhydrazone analogues of A-007 were synthesized and evaluated in vitro in a human primary cancer explant assay. Anticancer activities for selected analogues were also assayed for activity vs established human/murine cell lines. One-hundred-eighty-six fresh human solid tumors were used to screen for anticancer activity. Selected analogues were assayed for therapeutic indices (vs GM-CFC from bone marrow) in preparation for preclinical studies. Several polyaryl phenylhydrazones demonstrated improved cytotoxic activities by factors of 10(2)-10(3) when compared with A-007. However, the polyaryl quinone moieties of the latter analogues introduced potential toxic properties (cardiac, hematological) that do not exist with A-007.
Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Hidrazonas/síntese química , Hidrazonas/farmacologia , Fenóis/síntese química , Fenóis/farmacologia , Animais , Divisão Celular/efeitos dos fármacos , Cristalografia por Raios X , Técnicas de Cultura , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Ligação de Hidrogênio , Indicadores e Reagentes , Camundongos , Células-Tronco/efeitos dos fármacos , Relação Estrutura-Atividade , Células Tumorais CultivadasRESUMO
Gastric cancer is one of the most lethal types of cancer and its incidence varies worldwide, with the Andean region of South America showing high incidence rates. We evaluated the genetic structure of the population from Lima (Peru) and performed a case-control genetic association study to test the contribution of African, European, or Native American ancestry to risk for gastric cancer, controlling for the effect of non-genetic factors. A wide set of socioeconomic, dietary, and clinic information was collected for each participant in the study and ancestry was estimated based on 103 ancestry informative markers. Although the urban population from Lima is usually considered as mestizo (i.e., admixed from Africans, Europeans, and Native Americans), we observed a high fraction of Native American ancestry (78.4% for the cases and 74.6% for the controls) and a very low African ancestry (<5%). We determined that higher Native American individual ancestry is associated with gastric cancer, but socioeconomic factors associated both with gastric cancer and Native American ethnicity account for this association. Therefore, the high incidence of gastric cancer in Peru does not seem to be related to susceptibility alleles common in this population. Instead, our result suggests a predominant role for ethnic-associated socioeconomic factors and disparities in access to health services. Since Native Americans are a neglected group in genomic studies, we suggest that the population from Lima and other large cities from Western South America with high Native American ancestry background may be convenient targets for epidemiological studies focused on this ethnic group.
Assuntos
Indígenas Sul-Americanos/genética , Estado Nutricional , Neoplasias Gástricas , Adulto , Alelos , Feminino , Marcadores Genéticos , Predisposição Genética para Doença/etnologia , Predisposição Genética para Doença/genética , Humanos , Incidência , Indígenas Sul-Americanos/etnologia , Masculino , Pessoa de Meia-Idade , Peru/epidemiologia , Fatores Socioeconômicos , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/etnologia , Neoplasias Gástricas/genéticaRESUMO
BACKGROUND: The gastric pathogen Helicobacter pylori is extraordinary in its genetic diversity, the differences between strains from well-separated human populations, and the range of diseases that infection promotes. PRINCIPAL FINDINGS: Housekeeping gene sequences from H. pylori from residents of an Amerindian village in the Peruvian Amazon, Shimaa, were related to, but not intermingled with, those from Asia. This suggests descent of Shimaa strains from H. pylori that had infected the people who migrated from Asia into The Americas some 15,000+ years ago. In contrast, European type sequences predominated in strains from Amerindian Lima shantytown residents, but with some 12% Amerindian or East Asian-like admixture, which indicates displacement of ancestral purely Amerindian strains by those of hybrid or European ancestry. The genome of one Shimaa village strain, Shi470, was sequenced completely. Its SNP pattern was more Asian- than European-like genome-wide, indicating a purely Amerind ancestry. Among its unusual features were two cagA virulence genes, each distinct from those known from elsewhere; and a novel allele of gene hp0519, whose encoded protein is postulated to interact with host tissue. More generally, however, the Shi470 genome is similar in gene content and organization to those of strains from industrialized countries. CONCLUSIONS: Our data indicate that Shimaa village H. pylori descend from Asian strains brought to The Americas many millennia ago; and that Amerind strains are less fit than, and were substantially displaced by, hybrid or European strains in less isolated communities. Genome comparisons of H. pylori from Amerindian and other communities should help elucidate evolutionary forces that have shaped pathogen populations in The Americas and worldwide.
Assuntos
Genoma Bacteriano/genética , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Indígenas Sul-Americanos , América , Sequência de Aminoácidos , Ásia , Proteínas de Bactérias/genética , DNA Bacteriano/química , DNA Bacteriano/genética , Emigração e Imigração , Europa (Continente) , Variação Genética , Helicobacter pylori/classificação , Helicobacter pylori/isolamento & purificação , Humanos , Dados de Sequência Molecular , Peru , Filogenia , Dinâmica Populacional , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Especificidade da Espécie , Fatores de TempoRESUMO
The structure of the anticancer agent 4,4'-dihydroxybenzophenone-2,4-dinitrophenylhydrazone (A-007) has been modified through SAR and by incorporating barbituric acid, pyridine, quinoline, and alkylcarboxylic acids into A-007's moieties. Analogue anticancer activity and interacting with CD surface markers on a T-cell leukemia cell line were evaluated and the correlation between SAR and biological properties are discussed.