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1.
Nature ; 618(7964): 383-393, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37258665

RESUMO

The earliest events during human tumour initiation, although poorly characterized, may hold clues to malignancy detection and prevention1. Here we model occult preneoplasia by biallelic inactivation of TP53, a common early event in gastric cancer, in human gastric organoids. Causal relationships between this initiating genetic lesion and resulting phenotypes were established using experimental evolution in multiple clonally derived cultures over 2 years. TP53 loss elicited progressive aneuploidy, including copy number alterations and structural variants prevalent in gastric cancers, with evident preferred orders. Longitudinal single-cell sequencing of TP53-deficient gastric organoids similarly indicates progression towards malignant transcriptional programmes. Moreover, high-throughput lineage tracing with expressed cellular barcodes demonstrates reproducible dynamics whereby initially rare subclones with shared transcriptional programmes repeatedly attain clonal dominance. This powerful platform for experimental evolution exposes stringent selection, clonal interference and a marked degree of phenotypic convergence in premalignant epithelial organoids. These data imply predictability in the earliest stages of tumorigenesis and show evolutionary constraints and barriers to malignant transformation, with implications for earlier detection and interception of aggressive, genome-instable tumours.


Assuntos
Transformação Celular Neoplásica , Evolução Clonal , Lesões Pré-Cancerosas , Seleção Genética , Neoplasias Gástricas , Humanos , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Evolução Clonal/genética , Instabilidade Genômica , Mutação , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Lesões Pré-Cancerosas/genética , Lesões Pré-Cancerosas/patologia , Organoides/metabolismo , Organoides/patologia , Aneuploidia , Variações do Número de Cópias de DNA , Análise de Célula Única , Proteína Supressora de Tumor p53/deficiência , Proteína Supressora de Tumor p53/genética , Progressão da Doença , Linhagem da Célula
2.
Nature ; 597(7877): 549-554, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34497417

RESUMO

Monoclonal antibody therapies targeting tumour antigens drive cancer cell elimination in large part by triggering macrophage phagocytosis of cancer cells1-7. However, cancer cells evade phagocytosis using mechanisms that are incompletely understood. Here we develop a platform for unbiased identification of factors that impede antibody-dependent cellular phagocytosis (ADCP) using complementary genome-wide CRISPR knockout and overexpression screens in both cancer cells and macrophages. In cancer cells, beyond known factors such as CD47, we identify many regulators of susceptibility to ADCP, including the poorly characterized enzyme adipocyte plasma membrane-associated protein (APMAP). We find that loss of APMAP synergizes with tumour antigen-targeting monoclonal antibodies and/or CD47-blocking monoclonal antibodies to drive markedly increased phagocytosis across a wide range of cancer cell types, including those that are otherwise resistant to ADCP. Additionally, we show that APMAP loss synergizes with several different tumour-targeting monoclonal antibodies to inhibit tumour growth in mice. Using genome-wide counterscreens in macrophages, we find that the G-protein-coupled receptor GPR84 mediates enhanced phagocytosis of APMAP-deficient cancer cells. This work reveals a cancer-intrinsic regulator of susceptibility to antibody-driven phagocytosis and, more broadly, expands our knowledge of the mechanisms governing cancer resistance to macrophage phagocytosis.


Assuntos
Citotoxicidade Celular Dependente de Anticorpos/genética , Sistemas CRISPR-Cas , Citofagocitose/genética , Macrófagos/imunologia , Neoplasias/imunologia , Neoplasias/patologia , Animais , Anticorpos Monoclonais/imunologia , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Antígenos de Neoplasias/imunologia , Antígeno CD47/antagonistas & inibidores , Linhagem Celular Tumoral , Células Cultivadas , Feminino , Edição de Genes , Técnicas de Inativação de Genes , Humanos , Linfoma de Células T/imunologia , Linfoma de Células T/patologia , Macrófagos/citologia , Macrófagos/metabolismo , Masculino , Glicoproteínas de Membrana/deficiência , Glicoproteínas de Membrana/genética , Camundongos , Receptores Acoplados a Proteínas G/metabolismo
3.
Nat Mater ; 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37957268

RESUMO

Breast cancer becomes invasive when carcinoma cells invade through the basement membrane (BM)-a nanoporous layer of matrix that physically separates the primary tumour from the stroma. Single cells can invade through nanoporous three-dimensional matrices due to protease-mediated degradation or force-mediated widening of pores via invadopodial protrusions. However, how multiple cells collectively invade through the physiological BM, as they do during breast cancer progression, remains unclear. Here we developed a three-dimensional in vitro model of collective invasion of the BM during breast cancer. We show that cells utilize both proteases and forces-but not invadopodia-to breach the BM. Forces are generated from a combination of global cell volume expansion, which stretches the BM, and local contractile forces that act in the plane of the BM to breach it, allowing invasion. These results uncover a mechanism by which cells collectively interact to overcome a critical barrier to metastasis.

4.
Am J Otolaryngol ; 45(1): 104108, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37948826

RESUMO

BACKGROUND: The link between post-operative narcotic prescription and opioid misuse has spurred a nationwide effort to reduce perioperative opioid use. Previous work has suggested that perioperative gabapentin may reduce post-operative pain and opioid consumption across different procedures, although the optimal regimen remains to be defined. METHODS: Chronic rhinosinusitis (CRS) patients undergoing functional endoscopic sinus surgery (FESS) with or without septoplasty were randomized to receive a 7-day pre- and post-operative course of placebo or gabapentin, starting at 300 mg daily and titrated to 300 mg three times daily, in a double-blind fashion. Primary endpoint was pain level using a validated visual analog scale (VAS). Secondary endpoints included post-operative opioid consumption and side effects, as well as modified Lund-Kennedy endoscopy, Lund-Mackay, and SNOT-22 scores. RESULTS: Analysis of 35 patients (20 gabapentin, 15 control) showed no significant difference in mean postoperative VAS (p = 0.18) or postoperative opioid consumption between the placebo and gabapentin groups (2.3 and 4.8 oxycodone tablets respectively, p = 0.18). 15 of 35 patients did not require any post-operative oxycodone tablets, and only two patients required more than six tablets. CONCLUSION: Preliminary results show no significant change in pain after FESS with or without septoplasty in patients taking 7-day pre- and post-operative gabapentin versus placebo. Results also showed no significant difference in opioid consumption between the treatment and placebo groups. Post-operative pain scores and opioid requirements are both quite low following FESS. Many patients do not need opioids at all, suggesting that routine initial post-operative opioid prescriptions can be limited accordingly.


Assuntos
Analgésicos Opioides , Analgésicos , Humanos , Gabapentina/uso terapêutico , Analgésicos/uso terapêutico , Oxicodona , Manejo da Dor/métodos , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/etiologia , Dor Pós-Operatória/prevenção & controle , Método Duplo-Cego
5.
Langmuir ; 38(7): 2354-2362, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35143209

RESUMO

Influenza A virus (IAV) binds to sialylated glycans on the cell membrane before endocytosis and fusion. Cell-surface glycans are highly heterogeneous in length and glycosylation density, which leads to variations in the distance and rigidity with which IAV is held away from the cell membrane. To gain mechanistic insight into how receptor length and rigidity impact the mechanism of IAV entry, we employed synthetic DNA-lipids as highly tunable surrogate receptors. We tethered IAV to target membranes with a panel of DNA-lipids to investigate the effects of the distance and tether flexibility between virions and target membranes on the kinetics of IAV binding and fusion. Tether length and the presence of a flexible linker led to higher rates of IAV binding, while the efficiencies of lipid and content mixing were typically lower for longer and more rigid DNA tethers. For all DNA tether modifications, we found that the rates of IAV lipid and content mixing were unchanged. These results suggest that variations in the interface between IAV and a target membrane do not significantly impact the rate-limiting step of fusion or the low-pH-triggered engagement of viral fusion peptides with the target membrane. However, our results imply that the flexibility of the viral receptor is important for ensuring that hemifusion events are able to successfully proceed to pore formation.


Assuntos
Vírus da Influenza A , Receptores Artificiais , DNA/genética , DNA/metabolismo , Lipídeos , Fusão de Membrana , Receptores Artificiais/metabolismo , Internalização do Vírus
6.
Anesth Analg ; 135(5): 1097-1105, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-35350054

RESUMO

BACKGROUND: Opioid-induced respiratory depression (OIRD) is common on the medical and surgical wards and is associated with increased morbidity and health care costs. While previous studies have investigated risk factors for OIRD, the role of race remains unclear. We aim to investigate the association between race and OIRD occurrence on the medical/surgical ward. METHODS: This is a post hoc analysis of the PRediction of Opioid-induced respiratory Depression In patients monitored by capnoGraphY (PRODIGY) trial; a prospective multinational observational blinded study of 1335 general ward patients who received parenteral opioids and underwent blinded capnography and oximetry monitoring to identify OIRD episodes. For this study, demographic and perioperative data, including race and comorbidities, were analyzed and assessed for potential associations with OIRD. Univariable χ 2 and Mann-Whitney U tests were used. Stepwise selection of all baseline and demographic characteristics was used in the multivariable logistic regression analysis. RESULTS: A total of 1253 patients had sufficient racial data (317 Asian, 158 Black, 736 White, and 42 other races) for inclusion. The incidence of OIRD was 60% in Asians (N = 190/317), 25% in Blacks (N = 40/158), 43% in Whites (N = 316/736), and 45% (N = 19/42) in other races. Baseline characteristics varied significantly: Asians were older, more opioid naïve, and had higher opioid requirements, while Blacks had higher incidences of heart failure, obesity, and smoking. Stepwise multivariable logistic regression revealed that Asians had increased risk of OIRD compared to Blacks (odds ratio [OR], 2.49; 95% confidence interval [CI], 1.54-4.04; P = .0002) and Whites (OR, 1.38; 95% CI, 1.01-1.87; P = .0432). Whites had a higher risk of OIRD compared to Blacks (OR, 1.81; 95% CI, 1.18-2.78; P = .0067). The model's area under the curve was 0.760 (95% CI, 0.733-0.787), with a Hosmer-Lemeshow goodness-of-fit test P value of .23. CONCLUSIONS: This post hoc analysis of PRODIGY found a novel association between Asian race and increased OIRD incidence. Further study is required to elucidate its underlying mechanisms and develop targeted care pathways to reduce OIRD in susceptible populations.


Assuntos
Capnografia , Insuficiência Respiratória , Humanos , Analgésicos Opioides/efeitos adversos , Estudos Prospectivos , Insuficiência Respiratória/induzido quimicamente , Insuficiência Respiratória/diagnóstico , Insuficiência Respiratória/epidemiologia , Monitorização Fisiológica
7.
Am J Otolaryngol ; 43(4): 103476, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35567836

RESUMO

BACKGROUND: Preoperative corticosteroids have been shown to improve surgical visibility and intraoperative blood loss for chronic rhinosinusitis with nasal polyposis (CRSwNP) patients undergoing endoscopic sinus surgery (ESS). However, there is no consensus on the optimal dosing regimen. METHODS: A randomized, controlled trial was conducted to compare low, medium, and high dose corticosteroids prior to ESS. Patients with CRSwNP refractory to medical management were randomized to low (N = 8), medium (N = 10), or high (N = 5) dosing regimens of corticosteroids prior to ESS. Baseline disease severity was measured with the 22-item Sino-nasal Outcome Test and Lund-Mackay scores. Modified Lund-Kennedy endoscopic scores (MLKES) were measured at baseline and after corticosteroid treatment. Intraoperative parameters were measured including Boezaart surgical visibility score, intraoperative blood loss, and operative time. RESULTS: Medium dose corticosteroids demonstrated a superior surgical visibility score to low dose and comparable results to high dose, but these results were not significant (p = 0.33). No significant difference was observed between groups for total blood loss (p = 0.15), operative time (p = 0.87), or change in MLKES (p = 0.27). CONCLUSIONS: Current recommendations include the use of preoperative corticosteroids in patients with CRSwNP undergoing ESS, but there is no consensus on dose or duration. We did not find a statistically significant difference in surgical field visibility, intraoperative blood loss, or operative time between different dosing regimens. Further studies are needed to evaluate the efficacy of a low-dose preoperative regimen with the goal of reducing cumulative patient exposure to systemic corticosteroids.


Assuntos
Pólipos Nasais , Rinite , Sinusite , Corticosteroides/uso terapêutico , Perda Sanguínea Cirúrgica/prevenção & controle , Doença Crônica , Endoscopia/métodos , Humanos , Pólipos Nasais/complicações , Pólipos Nasais/tratamento farmacológico , Pólipos Nasais/cirurgia , Rinite/complicações , Rinite/tratamento farmacológico , Rinite/cirurgia , Sinusite/complicações , Sinusite/tratamento farmacológico , Sinusite/cirurgia , Resultado do Tratamento
8.
Biophys J ; 120(21): 4832-4841, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34536389

RESUMO

To infect a cell, enveloped viruses must first undergo membrane fusion, which proceeds through a hemifusion intermediate, followed by the formation of a fusion pore through which the viral genome is transferred to a target cell. Single-virus fusion studies to elucidate the dynamics of content mixing typically require extensive fluorescent labeling of viral contents. The labeling process must be optimized depending on the virus identity and strain and can potentially be perturbative to viral fusion behavior. Here, we introduce a single-virus assay in which content-labeled vesicles are bound to unlabeled influenza A virus (IAV) to eliminate the problematic step of content-labeling virions. We use fluorescence microscopy to observe individual, pH-triggered content mixing and content-loss events between IAV and target vesicles of varying cholesterol compositions. We show that target membrane cholesterol increases the efficiency of IAV content mixing and decreases the fraction of content-mixing events that result in content loss. These results are consistent with previous findings that cholesterol stabilizes pore formation in IAV entry and limits leakage after pore formation. We also show that content loss due to hemagglutinin fusion peptide engagement with the target membrane is independent of composition. This approach is a promising strategy for studying the single-virus content-mixing kinetics of other enveloped viruses.


Assuntos
Vírus da Influenza A , Influenza Humana , Colesterol , Humanos , Fusão de Membrana , Internalização do Vírus
9.
Blood ; 134(20): 1730-1744, 2019 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-31434702

RESUMO

Heterozygous deletions within chromosome 20q, or del(20q), are frequent cytogenetic abnormalities detected in hematologic malignancies. To date, identification of genes in the del(20q) common deleted region that contribute to disease development have remained elusive. Through assessment of patient gene expression, we have identified STK4 (encoding Hippo kinase MST1) as a 20q gene that is downregulated below haploinsufficient amounts in myelodysplastic syndrome (MDS) and myeloproliferative neoplasm (MPN). Hematopoietic-specific gene inactivation in mice revealed Hippo kinase loss to induce splenomegaly, thrombocytopenia, megakaryocytic dysplasia, and a propensity for chronic granulocytosis; phenotypes that closely resemble those observed in patients harboring del(20q). In a JAK2-V617F model, heterozygous Hippo kinase inactivation led to accelerated development of lethal myelofibrosis, recapitulating adverse MPN disease progression and revealing a novel genetic interaction between these 2 molecular events. Quantitative serum protein profiling showed that myelofibrotic transformation in mice was associated with cooperative effects of JAK2-V617F and Hippo kinase inactivation on innate immune-associated proinflammatory cytokine production, including IL-1ß and IL-6. Mechanistically, MST1 interacted with IRAK1, and shRNA-mediated knockdown was sufficient to increase IRAK1-dependent innate immune activation of NF-κB in human myeloid cells. Consistent with this, treatment with a small molecule IRAK1/4 inhibitor rescued the aberrantly elevated IL-1ß production in the JAK2-V617F MPN model. This study identified Hippo kinase MST1 (STK4) as having a central role in the biology of del(20q)-associated hematologic malignancies and revealed a novel molecular basis of adverse MPN progression that may be therapeutically exploitable via IRAK1 inhibition.


Assuntos
Neoplasias Hematológicas/genética , Síndromes Mielodisplásicas/genética , Transtornos Mieloproliferativos/genética , Proteínas Serina-Treonina Quinases/genética , Animais , Deleção Cromossômica , Cromossomos Humanos Par 20/genética , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Neoplasias Hematológicas/imunologia , Humanos , Imunidade Inata , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Síndromes Mielodisplásicas/imunologia , Transtornos Mieloproliferativos/imunologia , Proteínas Serina-Treonina Quinases/imunologia
10.
Biophys J ; 118(10): 2426-2433, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32298636

RESUMO

Host lipid composition influences many stages of the influenza A virus (IAV) entry process, including initial binding of IAV to sialylated glycans, fusion between the viral envelope and the host membrane, and the formation of a fusion pore through which the viral genome is transferred into a target cell. In particular, target membrane cholesterol has been shown to preferentially associate with virus receptors and alter physical properties of the membrane like fluidity and curvature. These properties affect both IAV binding and fusion, which makes it difficult to isolate the role of cholesterol in IAV fusion from receptor binding effects. Here, we develop a fusion assay that uses synthetic DNA-lipid conjugates as surrogate viral receptors to tether virions to target vesicles. To avoid the possibly perturbative effect of adding a self-quenched concentration of dye-labeled lipids to the viral membrane, we tether virions to lipid-labeled target vesicles and use fluorescence microscopy to detect individual, pH-triggered IAV membrane fusion events. Through this approach, we find that cholesterol in the target membrane enhances the efficiency of single-particle IAV lipid mixing, whereas the rate of lipid mixing is independent of cholesterol composition. We also find that the single-particle kinetics of influenza lipid mixing to target membranes with different cholesterol compositions is independent of receptor binding, suggesting that cholesterol-mediated spatial clustering of viral receptors within the target membrane does not significantly affect IAV hemifusion. These results are consistent with the hypothesis that target membrane cholesterol increases lipid mixing efficiency by altering host membrane curvature.


Assuntos
Vírus da Influenza A , Influenza Humana , Membrana Celular , Colesterol , Humanos , Fusão de Membrana , Membranas , Internalização do Vírus
11.
Ann Plast Surg ; 85(S1 Suppl 1): S28-S32, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32384351

RESUMO

BACKGROUND: A multitude of reconstructive options exist for patients after Mohs surgery of cutaneous neoplasms of the head and neck. Secondary intention healing is often overlooked and underused but has numerous advantages, including superior esthetic outcomes compared with surgical reconstruction for wounds that exhibit particular characteristics. The ability to predict cosmetic results based on wound characteristics can greatly help in the decision between surgical repair and secondary intention healing. Although other studies have discussed results after secondary intention healing on various areas of the head and neck, here, we specifically focus on cases of the nasal area. METHODS: We conducted a chart review of 37 patients with nasal reconstructions using secondary intention healing by a single surgeon over a 2-year period. Wound outcomes were graded as poor, acceptable, good, or excellent based on definitions found in the literature. RESULTS: We found that overall, the best cosmetic outcomes were associated with concave areas of the nose, such as the nasal ala and sidewall, and that superficial wounds healed better than deep wounds. Furthermore, we found that convex areas of the nose, such as the nasal tip, did not heal as well by secondary intention. However, if the wound was small and superficial enough, the wound still healed with a good to excellent cosmetic outcome. CONCLUSIONS: Healing by secondary intention is a reasonable consideration for suitable wounds. The need for surgical scar revision is addressed, if necessary, after the wound has healed. The benefits of secondary intention healing include:Future studies will address a larger cohort size of patients with more varied skin types and ages, as these are characteristics that can influence cosmetic outcome. Furthermore, healed wounds continue to improve in appearance over time, and it would be worthwhile to monitor patients' cosmetic outcomes over a longer follow-up period.


Assuntos
Intenção , Cicatrização , Cicatriz/patologia , Estética , Humanos , Cirurgia de Mohs
12.
Biophys J ; 113(2): 339-347, 2017 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-28711172

RESUMO

Previous work has shown that purified capsid protein (CP) of cowpea chlorotic mottle virus (CCMV) is capable of packaging both purified single-stranded RNA molecules of normal composition (comparable numbers of A, U, G, and C nucleobases) and of varying length and sequence, and anionic synthetic polymers such as polystyrene sulfonate. We find that CCMV CP is also capable of packaging polyU RNAs, which-unlike normal-composition RNAs-do not form secondary structures and which act as essentially structureless linear polymers. Following our canonical two-step assembly protocol, polyU RNAs ranging in length from 1000 to 9000 nucleotides (nt) are completely packaged. Surprisingly, negative-stain electron microscopy shows that all lengths of polyU are packaged into 22-nm-diameter particles despite the fact that CCMV CP prefers to form 28-nm-diameter (T = 3) particles when packaging normal-composition RNAs. PolyU RNAs >5000 nt in length are packaged into multiplet capsids, in which a single RNA molecule is shared between two or more 22-nm-diameter capsids, in analogy with the multiplets of 28-nm-diameter particles formed with normal-composition RNAs >5000 nt long. Experiments in which viral RNA competes for viral CP with polyUs of equal length show that polyU, despite its lack of secondary structure, is packaged more efficiently than viral RNA. These findings illustrate that the secondary structure of the RNA molecule-and its absence-plays an essential role in determining capsid structure during the self-assembly of CCMV-like particles.


Assuntos
Bromovirus/fisiologia , Proteínas do Capsídeo/metabolismo , Capsídeo/metabolismo , Conformação de Ácido Nucleico , RNA Viral , Montagem de Vírus , Bromovirus/química , Bromovirus/genética , Bromovirus/ultraestrutura , Capsídeo/química , Capsídeo/ultraestrutura , Proteínas do Capsídeo/química , Ensaio de Desvio de Mobilidade Eletroforética , Microscopia Eletrônica de Transmissão , RNA Viral/química
13.
Bioinformatics ; 32(18): 2817-23, 2016 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-27283948

RESUMO

MOTIVATION: A series of methods in population genetics use multilocus genotype data to assign individuals membership in latent clusters. These methods belong to a broad class of mixed-membership models, such as latent Dirichlet allocation used to analyze text corpora. Inference from mixed-membership models can produce different output matrices when repeatedly applied to the same inputs, and the number of latent clusters is a parameter that is often varied in the analysis pipeline. For these reasons, quantifying, visualizing, and annotating the output from mixed-membership models are bottlenecks for investigators across multiple disciplines from ecology to text data mining. RESULTS: We introduce pong, a network-graphical approach for analyzing and visualizing membership in latent clusters with a native interactive D3.js visualization. pong leverages efficient algorithms for solving the Assignment Problem to dramatically reduce runtime while increasing accuracy compared with other methods that process output from mixed-membership models. We apply pong to 225 705 unlinked genome-wide single-nucleotide variants from 2426 unrelated individuals in the 1000 Genomes Project, and identify previously overlooked aspects of global human population structure. We show that pong outpaces current solutions by more than an order of magnitude in runtime while providing a customizable and interactive visualization of population structure that is more accurate than those produced by current tools. AVAILABILITY AND IMPLEMENTATION: pong is freely available and can be installed using the Python package management system pip. pong's source code is available at https://github.com/abehr/pong CONTACT: aaron_behr@alumni.brown.edu or sramachandran@brown.edu SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Mineração de Dados , Grupos Populacionais , Software , Algoritmos , Análise por Conglomerados , Gráficos por Computador , Genética Populacional , Humanos , Linguagens de Programação , Conformação Proteica
14.
BMC Cancer ; 17(1): 172, 2017 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-28264666

RESUMO

BACKGROUND: Approximately 250 million people worldwide are chronically infected with hepatitis B virus (HBV) and more than half of the hepatocellular carcinoma (HCC) cases are attributed to this infection. As HCC has a high mortality rate, and current treatment options are remarkably limited, the development of new therapeutic treatment strategies is warranted. METHODS: In this study, woodchucks infected with woodchuck hepatitis virus (WHV), and with pre-existing liver tumors, were used as a model to investigate if complexes of cationic liposomes and non-coding DNA (JVRS-100) were effective in treatment of HCC. RESULTS: It was observed that the high serum viral load that is present in a typical chronic WHV infection (i.e., approximately 100-fold higher than human viral loads) results in immune suppression and resistance to treatment with JVRS-100. Treatment of woodchucks with lower serum viral load that more closely matched with the viral load usually seen in human HBV infection appears a better model for immunotherapeutic development based on the responsiveness to JVRS-100 treatment. In the latter case, marked declines in WHV DNA and WHV surface antigen were determined over the 12-week treatment period and WHV markers stayed suppressed during most time points of the 12-week follow-up period. Even more remarkably, the formation of new liver tumors was not observed in woodchucks treated with a well-tolerated dose of JVRS-100, as compared to several new tumors that developed in vehicle-treated control animals. CONCLUSIONS: Although there was little decrease in the volumes of the liver tumors existing at the time of treatment, it is generally accepted that preventing the spread and metastasis of almost always fatal cancers such as HCC and thus, reducing it to a chronic and treatable disease can also be a successful therapeutic approach. The results in woodchucks warrant the investigation of JVRS-100 as an intervention to prevent liver cancer in patients chronically infected with HBV and at high risk for HCC development.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , DNA/uso terapêutico , Vírus da Hepatite B da Marmota/efeitos dos fármacos , Hepatite B/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Metástase Neoplásica/prevenção & controle , Animais , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/patologia , DNA/administração & dosagem , Modelos Animais de Doenças , Feminino , Hepatite B/complicações , Lipossomos , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/patologia , Marmota/virologia , Carga Viral/efeitos dos fármacos
16.
J Hepatol ; 62(6): 1237-45, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25559326

RESUMO

BACKGROUND & AIMS: New therapies for chronic hepatitis B (CHB) are urgently needed since current treatments rarely lead to cure. We evaluated whether the oral small molecule toll-like receptor (TLR7) agonist GS-9620 could induce durable antiviral efficacy in woodchucks chronically infected with woodchuck hepatitis virus (WHV), a hepadnavirus closely related to human hepatitis B virus (HBV). METHODS: After evaluating the pharmacokinetics, pharmacodynamics and tolerability of oral GS-9620 in uninfected woodchucks, adult woodchucks chronically infected with WHV (n = 7 per group) were dosed with GS-9620 or placebo for 4 or 8 weeks with different treatment schedules. RESULTS: GS-9620 treatment induced rapid, marked and sustained reduction in serum viral DNA (mean maximal 6.2log10 reduction), and hepatic WHV DNA replicative intermediates, WHV cccDNA and WHV RNA, as well as loss of detectable serum WHV surface antigen (WHsAg). GS-9620 treatment also induced a sustained antibody response against WHsAg in a subset of animals. Strikingly, treatment reduced the incidence of hepatocellular carcinoma (HCC) from 71% in the placebo group to 8% in GS-9620-treated woodchucks with sustained viral load reduction. GS-9620 treatment was associated with reversible increases in serum liver enzymes and thrombocytopenia, and induced intrahepatic CD8(+) T cell, NK cell, B cell and interferon response transcriptional signatures. CONCLUSIONS: The data demonstrate that short duration, finite treatment with the oral TLR7 agonist GS-9620 can induce a sustained antiviral response in the woodchuck model of CHB, and support investigation of this compound as a therapeutic approach to attain a functional cure in CHB patients.


Assuntos
Antivirais/uso terapêutico , Vírus da Hepatite B da Marmota , Hepatite B/tratamento farmacológico , Hepatite B/imunologia , Pteridinas/uso terapêutico , Receptor 7 Toll-Like/agonistas , Animais , Antivirais/farmacocinética , DNA Viral/sangue , Modelos Animais de Doenças , Anticorpos Anti-Hepatite/sangue , Antígenos de Hepatite/sangue , Hepatite B/complicações , Vírus da Hepatite B da Marmota/efeitos dos fármacos , Vírus da Hepatite B da Marmota/genética , Vírus da Hepatite B da Marmota/isolamento & purificação , Humanos , Neoplasias Hepáticas Experimentais/etiologia , Neoplasias Hepáticas Experimentais/prevenção & controle , Masculino , Marmota , Pteridinas/farmacocinética , Soroconversão/efeitos dos fármacos , Fatores de Tempo , Resultado do Tratamento
17.
Soft Matter ; 11(42): 8217-20, 2015 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-26426824

RESUMO

Single-experiment analysis of phospholipid compositional gradients reveals diffusion coefficients, phase separation parameters, and binding densities as a function of localized lipid mixture. Compositional gradients are formed by directed self assembly where rapid-prototyping techniques (i.e., additive manufacturing or laser-cutting) prescribe lipid geometries that self-spread, heal and mix by diffusion.


Assuntos
Bicamadas Lipídicas/química , Fosfolipídeos/química , Difusão , Ligação Proteica , Propriedades de Superfície
18.
Laryngoscope ; 134(2): 741-748, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37540051

RESUMO

OBJECTIVES: To determine the utility of 5-aminolevulinic acid (5-ALA) fluorescence for resection of head and neck carcinoma. METHODS: In this prospective pilot trial, 5-ALA was administered as an oral suspension 3-5 h prior to induction of anesthesia for resection of head and neck squamous cell carcinoma (HNSCC). Following resection, 405 nm blue light was applied, and fluorescence of the tumor as well as the surgical bed was recorded. Specimen fluorescence intensity was graded categorically as none (score = 0), mild (1), moderate (2), or robust (3) by the operating surgeon intraoperatively and corroborated with final pathologic diagnosis. RESULTS: Seven patients underwent resection with 5-ALA. Five (83%) were male with an age range of 33-82 years (mean = 60). Sites included nasal cavity (n = 3), oral cavity (n = 3), and the larynx (n = 1). All specimens demonstrated robust fluorescence when 5-ALA was administered 3-5 h preoperatively. 5-ALA fluorescence predicted the presence of perineural invasion, a positive margin, and metastatic lymphadenopathy. Two patients had acute photosensitivity reactions, and one patient had a temporary elevation of hepatic enzymes. CONCLUSIONS: 5-ALA induces robust intraoperative fluorescence of HNSCC, capable of demonstrating a positive margin, perineural invasion, and metastatic nodal disease. Although no conclusions are there about the safety of this drug in the head and neck cancer population, our study parallels the extensive safety data in the neurosurgical literature. Future applications may include intraoperative assessment of margin status, diagnostic accuracy, and impacts on survival. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:741-748, 2024.


Assuntos
Neoplasias Encefálicas , Neoplasias de Cabeça e Pescoço , Cirurgia Assistida por Computador , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ácido Aminolevulínico , Neoplasias Encefálicas/patologia , Neoplasias de Cabeça e Pescoço/cirurgia , Margens de Excisão , Estudos Prospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço/cirurgia , Projetos Piloto
19.
Cancer Cell Int ; 13(1): 10, 2013 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-23388416

RESUMO

This study examined whether combining paclitaxel (taxol) with a novel epigenetic agent phenethyl isothiocyanate (PEITC) will yield a synergistic effect on inhibiting breast cancer cells. Two drug-resistant breast cancer cell lines, MCF7 and MDA-MB-231, were treated with PEITC and taxol. Cell growth, cell cycle, and apoptosis were examined. The combination of PEITC and taxol significantly decreased the IC50 of PEITC and taxol over each agent alone. The combination also increased apoptosis by more than two fold over each single agent in both cell lines. A significant increase of cells in the G2/M phases was detected. In conclusion, the combination of PEITC and taxol exhibits a synergistic effect on growth inhibition in breast cancer cells. This combination deserves further study in vivo.

20.
J Hosp Med ; 18(7): 588-594, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37039588

RESUMO

BACKGROUND: Environmental health represents the concept that a stable climate and clean environment are fundamental prerequisites for good human health. Despite growing awareness of the impact of climate change more broadly, knowledge of environmental health has not fully entered mainstream medicine in the United States. OBJECTIVE: To understand practicing hospitalists' perspectives regarding the current and future roles of environmental health within the practice of hospital medicine, as well as existing barriers and potential motivators to its further inclusion. METHODS: We conducted virtual focus groups of practicing hospitalists in partnership with the Hospital Medicine Reengineering Network from across the United States. Structured interviews elicited hospitalists' thoughts pertaining to environmental health. Transcripts then underwent descriptive coding to identify and group comments into themes. RESULTS: We conducted three focus groups with a total of 14 physician participants. Four themes emerged: the negative environmental impact of the healthcare system, a lack of prioritization of environmental health within hospital medicine, the potential for expanding environmental health in nonclinical roles including medical education, and the importance of systems-level support. CONCLUSION: Environmental health is felt to be of importance, and while there exist avenues to do better, there is limited understanding of hospitalists' most effective role in making change.


Assuntos
Educação Médica , Medicina Hospitalar , Médicos Hospitalares , Humanos , Estados Unidos , Médicos Hospitalares/educação , Medicina Hospitalar/educação , Grupos Focais , Saúde Ambiental
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