Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Lasers Surg Med ; 56(2): 142-149, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38247054

RESUMO

BACKGROUND AND OBJECTIVES: Fractional radiofrequency devices have been demonstrated to improve skin texture, such as smoothness, rhytides, brightness, and atrophic acne scars, by increasing dermal thickness, dermal collagen content, and dermal fibrillin content. The objective of the study is to assess the efficacy and adverse effects of this device on Asian patients of skin type III and IV with skin textural changes. MATERIALS AND METHODS: The study was designed as a prospective, open-labeled single-arm study, which was conducted with 20 Chinese patients aged 21-60 years and having irregularities in their skin texture, rhytides, and acne scars. The patients received six treatments at intervals of 4 weeks. Treatment was initiated with the maximum energy tolerated, which was then adjusted during the course of treatment if the patients felt excessive discomfort. A total of two passes were delivered in each session. Physician assessment results and standardized photographs were collected at the baseline, after all treatment visits, and at 1, 2, and 6 months after the final treatment visit. RESULTS: A total of 17 patients completed the study according to the established protocol. At the 6-month follow-up, 71% of patients were satisfied and 24% of patients were very satisfied with the received treatments, and the treatment physician reported varying degrees of improvement based on the global assessment scale in 60% of the subjects. While the anticipated side effects, such as erythema, edema, pinpoint bleeding, scab formation, and flare of acne, were noted in the patients, no serious adverse effects occurred. CONCLUSION: The use of fractional radiofrequency improves skin texture and is safe for use in Asian patients of skin type III and IV. No long-term serious adverse effects were noted.


Assuntos
Acne Vulgar , Cicatriz , Humanos , Acne Vulgar/radioterapia , Povo Asiático , Cicatriz/terapia , Estudos Prospectivos , Pele/patologia , Resultado do Tratamento , Adulto Jovem , Adulto , Pessoa de Meia-Idade
2.
Lasers Surg Med ; 2024 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-38922979

RESUMO

OBJECTIVE: Our study aimed to evaluate the efficacy of this novel dermal cooling system (DCS) in reducing pigmentation in benign pigmented lesions in Asian patients and its potential side effects. METHODS: It was a prospective open-label single-center study. Asian patients, with the presence of benign pigmented lesions mainly including lentigines, melasma, nevus spilus, ephelides, café au lait, and seborrheic keratosis were recruited for a novel DCS. The DCS provided localized cooling of the epidermal layer below freezing but was less intense than cryotherapy. Each patient received DCS at Week 0 and repeated at 4-week intervals up to 10 sessions. Global aesthetic improvement scores (GAIS) by blinded physicians and subjects were recorded at 2, 6, and 12 months posttreatment follow-up. RESULTS: Eighty-one patients were recruited with a total of 305 sessions performed and 1716 lesion sites treated. At 2-month posttreatment, 76.5% and 58.6% treatment sites showed obvious to marked improvement respectively and the improvement sustained at 6 and 12 months. Only minor adverse events were reported. Erythema and edema were the most commonly anticipated effects immediately after treatment. The pain was minimal. Postinflammatory hyperpigmentation was only reported in 2.2% (38/1716) treated sites. CONCLUSION: To our knowledge, this study was the first study to demonstrate that this novel DCS was an effective, safe, and well-tolerated treatment for benign pigmented lesions in Asians.

3.
Lasers Surg Med ; 53(8): 1032-1042, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33544930

RESUMO

BACKGROUND AND OBJECTIVES: Facial melasma is a disfiguring pigmentation and occurs frequently with aging skin. Topical treatment alone was often suboptimal. A recent study showed that fractional picosecond laser has promising result in benign pigmentary lesions. This study aims to investigate the efficacy and safety of 1064 nm picosecond laser in treatment of facial melasma and skin rejuvenation in Asian skin. STUDY DESIGN/MATERIALS AND METHODS: Patients of Asian descent seeking treatment for facial melasma and skin rejuvenation were screened and recruited. Each patient received up to nine laser treatments at 4-6 weeks intervals with a fractionated nonablative 1064 nm picosecond laser. Baseline and posttreatment modified Melasma Area Severity Index (mMASI) and Global Aesthetic Improvement Scale (IGAS) were assessed by blinded investigators based on the clinical photographs. Subject overall satisfaction was assessed by the questionnaires after treatment. All adverse events were documented. RESULTS: Twenty patients were recruited with a median age of 52.7 ± 8.2 years. Three subjects had Fitzpatrick skin type III and 17 had skin type IV. All subjects received nine laser sessions. Over 70% of patients were satisfied with the treatment outcomes. There was a statistically significant improvement in mMASI which reduced from 10.8 at baseline to 2.7 and 3.6 at 6 and 12 weeks post-treatment, respectively (both P < 0.01). For skin rejuvenation, 70% reported at least a moderate improvement at 6 weeks of post-treatment. No major side-effect was reported. Erythema was the most frequent transient response, while some reported edema (1.1%). Both resolved spontaneously. None reported hypo- or hyperpigmentation after treatment. The overall mean pain scare (VAS) was 1.92. CONCLUSION: Fractionated non-ablative 1064 nm picosecond laser was effective in treatment of melasma and skin rejuvenation. It was also safe and well tolerated. Importantly, there was no hypo or hyperpigmentation reported. Lasers Surg. Med. 00:00-00, 2021. © 2021 Wiley Periodicals LLC.


Assuntos
Hiperpigmentação , Lasers de Estado Sólido , Melanose , Envelhecimento da Pele , Adulto , Povo Asiático , Humanos , Lasers de Estado Sólido/uso terapêutico , Melanose/terapia , Pessoa de Meia-Idade , Estudos Prospectivos , Rejuvenescimento , Resultado do Tratamento
4.
Microvasc Res ; 102: 38-45, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26275748

RESUMO

Angiogenesis is triggered in response to hypoxia under many circumstances, from healthy cells and tissues during embryogenesis to pathological conditions like the formation of new blood vessels to supply tumours and promote invasive cancer. Siah2 has been shown to regulate the hypoxia pathway upstream of hypoxia-induced transcription factor subunit Hif-1alpha, and therefore may play an important role in angiogenesis in response to hypoxic stress in endothelial cells. This study aims to investigate the basic function of Siah2 in endothelial cells under hypoxia and to test the ability of Siah2 deficient cells to mount an angiogenic response when deprived of oxygen. We and others have previously shown that Siah2 is crucial for mediating the hypoxic response in many different cell types studied. In this study however, we describe that Siah2(-/-) endothelial cells have an intact hypoxic signalling pathway, including Hif-1alpha stabilisation and gene expression, the first report of a tissue or cell lineage in which the loss of Siah2 does not seem to impact hypoxic response signalling. In mice, the infiltration of Siah2(-/-) endothelial cells into a Matrigel plug containing a VEGF-A attractant was similar compared with wildtype endothelial cells. Ex vivo however, there was a reduced capacity of Siah2(-/-) aorta to form tubes or new vessels. Thus, we conclude that Siah2 is not essential for the hypoxic response of endothelial cells.


Assuntos
Células Endoteliais/citologia , Células Endoteliais/metabolismo , Neovascularização Fisiológica , Ubiquitina-Proteína Ligases/deficiência , Animais , Aorta/citologia , Aorta/crescimento & desenvolvimento , Aorta/metabolismo , Hipóxia Celular/genética , Hipóxia Celular/fisiologia , Células Cultivadas , Expressão Gênica , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Técnicas In Vitro , Camundongos , Camundongos Knockout , Microvasos/citologia , Microvasos/crescimento & desenvolvimento , Microvasos/metabolismo , Proteínas/genética , Transdução de Sinais , Ubiquitina-Proteína Ligases/genética
5.
Wound Repair Regen ; 21(3): 437-47, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23627548

RESUMO

Hypoxia is associated with the dermal wound healing process and hypoxia signaling is presumed to be crucial for normal wound repair. The Siah2 ubiquitin ligase controls the abundance of hypoxia-inducible factor-1 alpha, and loss of Siah2 results in destabilization of hypoxia-inducible factor-1 alpha under hypoxia. Utilizing Siah2(-/-) mice we demonstrate that cutaneous wound healing is impaired in these mice. Wounds in Siah2(-/-) mice heal slower and are associated with delayed induction of myofibroblast infiltration and reduced collagen deposition. This coincides with delayed angiogenesis and reduced macrophage infiltration into the wounds of Siah2(-/-) mice. We furthermore demonstrate that primary Siah2(-/-) dermal fibroblasts have reduced migratory capacities and produce less collagen than wild-type fibroblasts. Additionally, Siah2(-/-) fibroblasts showed conserved responses to transforming growth factor-ß at the receptor level (pSmad 2C activation) but reduced responses downstream. Together, our data show, for the first time, that Siah2 is involved as a positive regulator in the wound healing response. Understanding the role of hypoxia signaling in tissue repair and fibrosis and interference with the hypoxia signaling pathway via regulation of Siah2 may provide new targets for clinical regulation of fibrosis and scarring.


Assuntos
Hipóxia/metabolismo , Ubiquitina-Proteína Ligases/deficiência , Cicatrização/fisiologia , Ferimentos e Lesões/metabolismo , Animais , Western Blotting , Movimento Celular , Células Cultivadas , Modelos Animais de Doenças , Feminino , Fibroblastos/patologia , Seguimentos , Hipóxia/patologia , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ferimentos e Lesões/patologia
6.
Asia Pac Allergy ; 12(1): e10, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35174061

RESUMO

Delayed hypersensitivity reaction of penicillin is commonly seen, but never reported in pyridium. This case illustrates a patient with delayed hypersensitivity reaction after the use of augmentin and pyridium. Skin patch test, surprisingly, confirmed pyridium delayed hypersensitivity.

7.
J Contin Educ Nurs ; 53(4): 165-170, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35357991

RESUMO

Background Although training can improve the quality of clinical teaching for nurse preceptors, research on the training needs of junior versus senior preceptors is limited. This study sought to examine the differences in their needs by comparing their clinical teaching experience and the training they received. Method A secondary analysis of a cross-sectional survey was conducted in three hospitals using the Clinical Teaching Behavior Inventory (CTBI). Survey data were analyzed using the chi-square test, the independent t test, and multiple regression analysis. Results The differences (N = 252) in the subscales of building a learning atmosphere and committing to teaching were not statistically significant (p > .05). Generally, the mean CTBI scores of trained junior preceptors were significantly higher than those of untrained senior preceptors (p < .001). Conclusion Training yields more significant improvements in self-perceived clinical teaching behavior than clinical teaching experience. [J Contin Educ Nurs. 2022;53(4):165-170.].


Assuntos
Aprendizagem , Preceptoria , Estudos Transversais , Humanos , Preceptoria/métodos , Inquéritos e Questionários
8.
Int J Dermatol ; 61(2): 184-190, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34553372

RESUMO

BACKGROUND: HLA-B*15:11 is associated with carbamazepine (CBZ)-induced severe cutaneous adverse drug reactions (SCARs) in Japanese and some Asian populations, but such data remains relatively limited in Chinese. Routine HLA-B*15:02 screening is mandatory before CBZ commencement, however, SCARs related to CBZ were still observed in non-HLA*B-15:02 carriers. OBJECTIVE: We aimed to find out the prevalence of HLA-B*15:11 in Chinese patients and its associations with CBZ-induced SCARs. METHOD: We screened 8,328 blood samples collected for HLA allele typing before CBZ commencement during the period of January 2014 to December 2019. In HLA-B*15:02 negative Chinese patients, HLA-B*15:11 status were further screened, and the incidence of SCARs in the CBZ group was compared with the control group without CBZ use. RESULT: In this cohort, 1416 out of 8328 patients (17%) tested HLA-B*15:02 positive and were advised to avoid CBZ, while 80 (0.96%) were found to be HLA-B*15:11 positive. In 6911 (83%) patients who tested HLA-B*15:02 negative, 70 (1.01%) were HLA-B*15:11 positive. Five out of 70 (7.14%) patients had SCARs. The incidence of SCARs in HLA-B*15:11 carriers who received CBZ was significantly higher than those without CBZ (17.4% [4/23] vs. 2.13% [1/47], P = 0.037*). The odds ratio was 9.68 (95% CI 1.02-92.4, P = 0.048*). These included: one Stevens-Johnson syndrome (SJS), two DRESS, and one MPE after CBZ use, while one developed MPE after phenytoin use in control. CONCLUSION: HLA-B*15:11 is a potential risk factor of CBZ-induced SCARs in HLA-B*15:02 negative Chinese patients. Further screening of HLA-B*15:11 status in those HLA-B*15:02 negative patients is recommended to avoid undesirable SCARs.


Assuntos
Anticonvulsivantes , Síndrome de Stevens-Johnson , Carbamazepina , China , Predisposição Genética para Doença , Antígenos HLA-B/genética , Antígeno HLA-B15/genética , Humanos
9.
Breast Cancer Res ; 13(1): R19, 2011 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-21306611

RESUMO

INTRODUCTION: The seven in absentia homolog 2 (SIAH2) protein plays a significant role in the hypoxic response by regulating the abundance of hypoxia-inducible factor-α; however, its role in breast carcinoma is unclear. We investigated the frequency and expression pattern of SIAH2 in two independent cohorts of sporadic breast cancers. METHODS: Immunohistochemical evaluation of SIAH2protein expression was conducted in normal breast tissues and in tissue microarrays comprising ductal carcinoma in situ (DCIS) and a cohort of invasive breast carcinomas. Correlation analysis was performed between SIAH2 and clinicopathological variables and intrinsic breast cancer subgroups and validated in a cohort of 293 invasive ductal carcinomas. Promoter methylation, gene copy number and mRNA expression of SIAH2 were determined in a panel of basal-like tumors and cell lines. RESULTS: There was a significant increase in nuclear SIAH2 expression from normal breast tissues through to DCIS and progression to invasive cancers. A significant inverse correlation was apparent between SIAH2 and estrogen receptor and progesterone receptor and a positive association with tumor grade, HER2, p53 and an intrinsic basal-like subtype. Logistic regression analysis confirmed the significant positive association between SIAH2 expression and the basal-like phenotype. No SIAH2 promoter methylation was identified, yet there was a significant correlation between SIAH2 mRNA and gene copy number. SIAH2-positive tumors were associated with a shorter relapse-free survival in univariate but not multivariate analysis. CONCLUSIONS: SIAH2 expression is upregulated in basal-like breast cancers via copy number changes and/or transcriptional activation by p53 and is likely to be partly responsible for the enhanced hypoxic drive through abrogation of the prolyl hydroxylases.


Assuntos
Neoplasias da Mama/genética , Dosagem de Genes , Proteínas Nucleares/genética , Fenótipo , Proteína Supressora de Tumor p53/metabolismo , Ubiquitina-Proteína Ligases/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Estudos de Coortes , Metilação de DNA , Feminino , Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Glândulas Mamárias Humanas/metabolismo , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas , Ubiquitina-Proteína Ligases/metabolismo , Adulto Jovem
10.
Cureus ; 13(9): e18260, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34712535

RESUMO

Metoclopramide is a dopamine D2-receptor blocking agent commonly used to treat nausea, vomiting, and gastroparesis. Due to their mechanism of action, these drugs can lead to extrapyramidal side effects such as tardive dyskinesia. In this article, we report a case of a nulliparous gynecology patient who developed dyskinetic movements after intraoperative administration of metoclopramide. During further workup after stabilization, she was found to have several risk factors for tardive dyskinesia. As the occurrence of this phenomenon is somewhat rare, this case report aims to discuss the condition, associated risk factors, and differentiation from other diagnoses.

11.
JAMA Netw Open ; 4(5): e218824, 2021 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-33938934

RESUMO

Importance: Schools were closed intermittently across Hong Kong to control the COVID-19 outbreak, which led to significant physical and psychosocial problems among children and youths. Objective: To compare the clinical characteristics and sources of infection among children and youths with COVID-19 during the 3 waves of outbreaks in Hong Kong in 2020. Design, Setting, and Participants: This cross-sectional study involved children and youths aged 18 years or younger with COVID-19 in the 3 waves of outbreaks from January 23 through December 2, 2020. Data were analyzed from December 2020 through January 2021. Main Outcomes and Measures: Demographic characteristics, travel and contact histories, lengths of hospital stay, and symptoms were captured through the central electronic database. Individuals who were infected without recent international travel were defined as having domestic infections. Results: Among 397 children and youths confirmed with COVID-19 infections, the mean (SD) age was 9.95 (5.34) years, 220 individuals (55.4%) were male, and 154 individuals (38.8%) were asymptomatic. There were significantly more individuals who were infected without symptoms in the second wave (59 of 118 individuals [50.0%]) and third wave (94 of 265 individuals [35.5%]) than in the first wave (1 of 14 individuals [7.1%]) (P = .001). Significantly fewer individuals who were infected in the second and third waves, compared with the first wave, had fever (first wave: 10 individuals [71.4%]; second wave: 22 individuals [18.5%]; third wave: 98 individuals [37.0%]; P < .001) or cough (first wave: 6 individuals [42.9%]; second wave: 15 individuals [12.7%]; third wave: 52 individuals [19.6%]; P = .02). Among all individuals, 394 individuals (99.2%) had mild illness. One patient developed chilblains (ie, COVID toes), 1 patient developed multisystem inflammatory syndrome in children, and 1 patient developed post-COVID-19 autoimmune hemolytic anemia. In all 3 waves, 204 patients with COVID-19 (51.4%) had domestic infections. Among these individuals, 186 (91.2%) reported having a contact history with another individual with COVID-19, of which most (183 individuals [90.0%]) were family members. In the third wave, 18 individuals with domestic infections had unknown contact histories. Three schoolmates were confirmed with COVID-19 on the same day and were reported to be close contacts. Conclusions and Relevance: This cross-sectional study found that nearly all children and youths with COVID-19 in Hong Kong had mild illness. These findings suggest that household transmission was the main source of infection for children and youths with domestic infections and that the risk of being infected at school was small.


Assuntos
Infecções Assintomáticas/epidemiologia , COVID-19 , Busca de Comunicante , SARS-CoV-2/isolamento & purificação , Avaliação de Sintomas , Adolescente , COVID-19/epidemiologia , COVID-19/terapia , COVID-19/transmissão , Criança , Busca de Comunicante/métodos , Busca de Comunicante/estatística & dados numéricos , Estudos Transversais , Transmissão de Doença Infecciosa/prevenção & controle , Transmissão de Doença Infecciosa/estatística & dados numéricos , Características da Família , Feminino , Hong Kong/epidemiologia , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Índice de Gravidade de Doença , Avaliação de Sintomas/métodos , Avaliação de Sintomas/estatística & dados numéricos , Doença Relacionada a Viagens
12.
NPJ Breast Cancer ; 5: 4, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30675514

RESUMO

The effective treatment of cerebral metastases from HER2-positive breast cancer remains an unmet need. Recent studies indicate that activated astrocytes and brain endothelial cells exert chemoprotective effects on cancer cells through direct physical interaction. Here we report that the endothelin axis mediates protection of HER2-amplified brain metastatic breast cancers to the anti-HER2 antibody-drug conjugate ado-trastuzumab emtansine (T-DM1). Macitentan, a dual inhibitor of endothelin receptors A and B, improves the efficacy of T-DM1 against breast cancers grown in the brain. We show that direct contact of brain stroma with cancer cells is required for protection to T-DM1. Our data suggest that targeting the endothelin axis may be beneficial when anti-signaling agent and cytotoxic agent are combined. These findings may contribute to the development of therapeutic approaches with enhanced efficacy in the brain microenvironment.

13.
PLoS One ; 13(4): e0196040, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29677215

RESUMO

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid progenitor cells that are expanded in cancer and act as potent suppressors of the anti-tumor immune response. MDSCs consist of two major subsets, namely monocytic (M-) MDSCs and granulocytic (G-) MDSCs that differ with respect to their phenotype, morphology and mechanisms of suppression. Here, we cultured bone marrow cells with IL-6 and GM-CSF in vitro to generate a population of bone marrow MDSCs (BM-MDSCs) similar to G-MDSCs from tumor-bearing mice in regards to phenotype, morphology and suppressive-function. Through fluorescent labeling of these BM-MDSCs and optical imaging, we could visualize the recruitment and localization of BM-MDSCs in breast tumor-bearing mice in vivo. Furthermore, we were able to demonstrate that BM-MDSCs home to primary and metastatic breast tumors, but have no significant effect on tumor growth or progression. Ex vivo flow cytometry characterization of BM-MDSCs after adoptive transfer demonstrated both organ-and tumor-specific effects on their phenotype and differentiation, demonstrating the importance of the local microenvironment on MDSC fate and function. In this study, we have developed a method to generate, visualize and detect BM-MDSCs in vivo and ex vivo through optical imaging and flow cytometry, in order to understand the organ-specific changes rendered to MDSCs in breast cancer.


Assuntos
Transferência Adotiva/métodos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Interleucina-6/farmacologia , Neoplasias Mamárias Experimentais/diagnóstico por imagem , Células Supressoras Mieloides/citologia , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/imunologia , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Células Cultivadas , Feminino , Ativação Linfocitária , Neoplasias Mamárias Experimentais/imunologia , Camundongos , Células Supressoras Mieloides/imunologia , Metástase Neoplásica , Imagem Óptica , Transplante de Células-Tronco , Microambiente Tumoral
14.
Adv Drug Deliv Rev ; 119: 159-174, 2017 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-28648712

RESUMO

Five-year survival rates have not increased appreciably for patients with primary and metastatic brain tumors. Nearly 17,000 patients die from primary brain tumors, whereas approximately 200,000 cases are diagnosed with brain metastasis every year in the US alone. At the same time, with improved control of systemic disease, the incidence of brain metastasis is increasing. Thus, novel approaches for improving the treatment outcome for these uniformly fatal diseases are needed urgently. In the review, we summarize the challenges in the treatment of these diseases using antiangiogenic therapies alone or in combination with radio-, chemo- and immuno-therapies. We also discuss the emerging strategies to improve the treatment outcome using both pharmacological approaches to normalize the tumor microenvironment and physical approaches (e.g., focused ultrasound) to modulate the blood-tumor-barrier, along with limitations of each approach. Finally, we offer some new avenues of future research.


Assuntos
Inibidores da Angiogênese/farmacologia , Inibidores da Angiogênese/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Animais , Humanos , Taxa de Sobrevida , Microambiente Tumoral/efeitos dos fármacos
15.
Sci Transl Med ; 9(391)2017 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-28539475

RESUMO

Although targeted therapies are often effective systemically, they fail to adequately control brain metastases. In preclinical models of breast cancer that faithfully recapitulate the disparate clinical responses in these microenvironments, we observed that brain metastases evade phosphatidylinositide 3-kinase (PI3K) inhibition despite drug accumulation in the brain lesions. In comparison to extracranial disease, we observed increased HER3 expression and phosphorylation in brain lesions. HER3 blockade overcame the resistance of HER2-amplified and/or PIK3CA-mutant breast cancer brain metastases to PI3K inhibitors, resulting in marked tumor growth delay and improvement in mouse survival. These data provide a mechanistic basis for therapeutic resistance in the brain microenvironment and identify translatable treatment strategies for HER2-amplified and/or PIK3CA-mutant breast cancer brain metastases.


Assuntos
Neoplasias Encefálicas/metabolismo , Neoplasias da Mama/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Receptor ErbB-3/metabolismo , Animais , Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/secundário , Neoplasias da Mama/complicações , Neoplasias da Mama/tratamento farmacológico , Feminino , Camundongos , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/uso terapêutico , Receptor ErbB-3/antagonistas & inibidores , Receptor ErbB-3/genética
16.
Cancer Res ; 76(23): 6816-6827, 2016 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-27760789

RESUMO

Small membranous secretions from tumor cells, termed exosomes, contribute significantly to intercellular communication and subsequent reprogramming of the tumor microenvironment. Here, we use optical imaging to determine that exogenously administered fluorescently labeled exosomes derived from highly metastatic murine breast cancer cells distributed predominantly to the lung of syngeneic mice, a frequent site of breast cancer metastasis. At the sites of accumulation, exosomes were taken up by CD45+ bone marrow-derived cells. Subsequent long-term conditioning of naïve mice with exosomes from highly metastatic breast cancer cells revealed the accumulation of myeloid-derived suppressor cells in the lung and liver. This favorable immune suppressive microenvironment was capable of promoting metastatic colonization in the lung and liver, an effect not observed from exosomes derived from nonmetastatic cells and liposome control vesicles. Furthermore, we determined that breast cancer exosomes directly suppressed T-cell proliferation and inhibited NK cell cytotoxicity, and hence likely suppressed the anticancer immune response in premetastatic organs. Together, our findings provide novel insight into the tissue-specific outcomes of breast cancer-derived exosome accumulation and their contribution to immune suppression and promotion of metastases. Cancer Res; 76(23); 6816-27. ©2016 AACR.


Assuntos
Neoplasias da Mama/imunologia , Exossomos/metabolismo , Terapia de Imunossupressão/métodos , Animais , Neoplasias da Mama/patologia , Proliferação de Células , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL
17.
J Extracell Vesicles ; 4: 27031, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26194179

RESUMO

Extracellular vesicles represent a rich source of novel biomarkers in the diagnosis and prognosis of disease. However, there is currently limited information elucidating the most efficient methods for obtaining high yields of pure exosomes, a subset of extracellular vesicles, from cell culture supernatant and complex biological fluids such as plasma. To this end, we comprehensively characterize a variety of exosome isolation protocols for their efficiency, yield and purity of isolated exosomes. Repeated ultracentrifugation steps can reduce the quality of exosome preparations leading to lower exosome yield. We show that concentration of cell culture conditioned media using ultrafiltration devices results in increased vesicle isolation when compared to traditional ultracentrifugation protocols. However, our data on using conditioned media isolated from the Non-Small-Cell Lung Cancer (NSCLC) SK-MES-1 cell line demonstrates that the choice of concentrating device can greatly impact the yield of isolated exosomes. We find that centrifuge-based concentrating methods are more appropriate than pressure-driven concentrating devices and allow the rapid isolation of exosomes from both NSCLC cell culture conditioned media and complex biological fluids. In fact to date, no protocol detailing exosome isolation utilizing current commercial methods from both cells and patient samples has been described. Utilizing tunable resistive pulse sensing and protein analysis, we provide a comparative analysis of 4 exosome isolation techniques, indicating their efficacy and preparation purity. Our results demonstrate that current precipitation protocols for the isolation of exosomes from cell culture conditioned media and plasma provide the least pure preparations of exosomes, whereas size exclusion isolation is comparable to density gradient purification of exosomes. We have identified current shortcomings in common extracellular vesicle isolation methods and provide a potential standardized method that is effective, reproducible and can be utilized for various starting materials. We believe this method will have extensive application in the growing field of extracellular vesicle research.

18.
Oncotarget ; 6(2): 862-73, 2015 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-25528765

RESUMO

Elucidating the mechanisms that underlie metastasis is of paramount importance to understanding tumor progression and to the development of novel therapeutics. Epithelial to Mesenchymal Transition (EMT) plays a vital role in tumor cell dissemination and is regulated by a core cassette of transcription factors. Despite recent advances, the molecular pathways that regulate the EMT program have not yet been fully delineated. We show that Siah ubiquitin ligases regulate Zeb1 protein, a key EMT transcription factor. The induction of EMT in breast cancer cells leads to the down-regulation of Siah, while the loss of Siah induces a mesenchymal phenotype, concurrent with an up-regulation of Zeb1. Overexpression of Siah in vitro mediates Zeb1 degradation, which can be blocked with a Siah peptide inhibitor. Thus, this work demonstrates that Siah is a novel regulator of EMT. This work is the first to identify a mechanism of post-translational regulation of the key Epithelial to Mesenchymal Transition transcription factor Zeb1.


Assuntos
Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Proteínas de Homeodomínio/genética , Proteínas Nucleares/genética , Fatores de Transcrição/genética , Ubiquitina-Proteína Ligases/genética , Animais , Western Blotting , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Feminino , Perfilação da Expressão Gênica , Proteínas de Homeodomínio/metabolismo , Humanos , Células MCF-7 , Camundongos , Microscopia de Fluorescência , Modelos Genéticos , Proteínas Nucleares/metabolismo , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Fatores de Transcrição/metabolismo , Fator de Crescimento Transformador alfa/farmacologia , Fator de Crescimento Transformador beta/farmacologia , Ubiquitina-Proteína Ligases/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco
19.
Cancer Immunol Res ; 3(11): 1207-17, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26198985

RESUMO

Metastatic progression is the major cause of breast cancer-related mortality. By examining multiple syngeneic preclinical breast cancer models in mice lacking a functional type-I interferon receptor (Ifnar1(-/-) mice), we show that host-derived type-I interferon (IFN) signaling is a critical determinant of metastatic spread that is independent of primary tumor growth. In particular, we show that bone metastasis can be accelerated in Balb/c Ifnar1(-/-) mice bearing either 4T1 or 66cl4 orthotopic tumors and, for the first time, present data showing the development of bone metastasis in the C57Bl/6 spontaneous MMTV-PyMT-driven model of tumorigenesis. Further exploration of these results revealed that endogenous type-I IFN signaling to the host hematopoietic system is a key determinant of metastasis-free survival and critical to the responsiveness of the circulating natural killer (NK)-cell population. We find that in vivo-stimulated NK cells derived from wild-type, but not Ifnar1(-/-), mice can eliminate the 4T1 and 66cl4 breast tumor lines with varying kinetics in vitro. Together, this study indicates that the dysregulated immunity resulting from a loss of host type-I IFN signaling is sufficient to drive metastasis, and provides a rationale for targeting the endogenous type-I IFN pathway as an antimetastatic strategy.


Assuntos
Neoplasias Ósseas/secundário , Interferon Tipo I/imunologia , Células Matadoras Naturais/imunologia , Neoplasias Mamárias Experimentais/imunologia , Animais , Apoptose/imunologia , Neoplasias Ósseas/imunologia , Progressão da Doença , Feminino , Células Matadoras Naturais/transplante , Neoplasias Mamárias Experimentais/patologia , Neoplasias Mamárias Experimentais/terapia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de Interferon/deficiência , Transdução de Sinais/imunologia
20.
Cancer Res ; 73(8): 2400-6, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23455005

RESUMO

Siah ubiquitin ligases play important roles in a number of signaling pathways involved in the progression and spread of cancer in cell-based models, but their role in tumor progression remains controversial. Siah proteins have been described to be both oncogenic and tumor suppressive in a variety of patient cohort studies and animal cancer models. This review collates the current knowledge of Siah in cancer progression and identifies potential methods of translation of these findings into the clinic. Furthermore, key experiments needed to close the gaps in our understanding of the role Siah proteins play in tumor progression are suggested.


Assuntos
Neoplasias/metabolismo , Proteínas Nucleares/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Modelos Animais de Doenças , Humanos , Terapia de Alvo Molecular , Neoplasias/genética , Neoplasias/terapia , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Proteínas Oncogênicas/genética , Proteínas Oncogênicas/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina-Proteína Ligases/antagonistas & inibidores , Ubiquitina-Proteína Ligases/genética
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa