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1.
Fish Shellfish Immunol ; 120: 560-568, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34958920

RESUMO

To evaluate the effects of dietary short chain fatty acids (SCFAs) on the intestinal health and innate immunity in crucian carp, a six-week feeding trial was carried out with following treatments: basal diet (BD), basal diet supplementation with 1% sodium acetate (BDSA), basal diet supplementation with 1% sodium propionate (BDSP) and basal diet supplementation with 1% sodium butyrate (BDSB). The results showed dietary BDSA, BDSP and BDSB could protect the host against oxidative stress by improving the activity of certain antioxidative enzymes (T-SOD, GSH-Px and CAT). Additionally, dietary SCFAs could enhance mucosal and humoral immune responses by improving certain innate immune parameters in serum and skin mucus productions (IgM, ACH50 and T-SOD). Furthermore, dietary BDSA and BDSP could up-regulate the expression of immune related genes (TNF-α, TGF-ß and IL-8) and tight junction protein genes (occludin and ZO-1). Dietary BDSB could also elevate the expression of IL-8, TGF-ß, ZO-1 and Occludin in the midgut. Although dietary differences of SCFAs didn't alter the α-diversity of the intestinal flora, they altered the core microbiota. Finally, the challenge trial showed that dietary basal diet supplementation with SCFAs could protect zebrafish against Aeromonas hydrophila. These results suggest that dietary SCFAs could improve innate immunity, modulate gut microbiota and increase disease resistance in the host, which indicated the potential of SCFAs as immunostimulants in aquaculture.


Assuntos
Dieta , Resistência à Doença , Ácidos Graxos Voláteis , Doenças dos Peixes , Microbioma Gastrointestinal , Peixe-Zebra , Aeromonas hydrophila , Ração Animal/análise , Animais , Antioxidantes , Dieta/veterinária , Suplementos Nutricionais/análise , Ácidos Graxos Voláteis/administração & dosagem , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Interleucina-8 , Ocludina , Superóxido Dismutase , Fator de Crescimento Transformador beta , Peixe-Zebra/imunologia , Peixe-Zebra/microbiologia
2.
Dermatol Surg ; 48(1): 47-50, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34743122

RESUMO

BACKGROUND: Deep transection of invasive melanoma precludes accurate measurement of Breslow depth, which may affect tumor staging. OBJECTIVE: To determine the frequency of upstaging of transected invasive melanomas after excision, characterize the impact on National Comprehensive Cancer Network (NCNN)-recommended treatment, and determine predictors of subsequent upstaging. MATERIALS AND METHODS: A retrospective review of invasive melanomas between January 2017 and December 2019 at a single institution. Deeply transected biopsy reports were compared with subsequent excisions to calculate the frequency of upstaging. RESULTS: Three hundred sixty (49.6%) of 726 invasive melanomas identified were transected. Forty-nine (13.6%) transected tumors had upstaging that would have altered NCCN-recommended management. "Broadly" transected tumors had upstaging that would have resulted in a change in the management in 5/23 cases (21.7%) versus 2/41 cases (4.9%) for "focally" transected tumors (p = .038). Breslow depth increased by 0.59 mm on average for "broad" transection versus 0.06 mm for "focal" transection (p =< .01). Of the 89 transected pT1a melanomas, specimens with gross residual tumor or pigment after biopsy were upstaged in 8/17 (47.1%) of cases versus 5/72 (6.9%) of specimens without (p =< .01). CONCLUSION: Upstaging of deeply transected invasive melanomas that would alter NCCN-recommended management occurred in 13.6% of cases. Broad transection and gross residual tumor or pigment after biopsy predicted higher likelihood of upstaging.


Assuntos
Melanoma/diagnóstico , Neoplasias Cutâneas/diagnóstico , Pele/patologia , Biópsia , Feminino , Humanos , Masculino , Melanoma/patologia , Melanoma/cirurgia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasia Residual , Estudos Retrospectivos , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/cirurgia
3.
J Gastrointest Surg ; 26(2): 433-443, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34581979

RESUMO

BACKGROUND: Racial disparities in colorectal surgery outcomes have been studied extensively in the USA, and access to healthcare resources may contribute to these differences. The Veterans Health Administration (VHA) is the largest integrated healthcare network in the USA with the potential for equal access care to veterans. The objective of this study is to evaluate the VHA for the presence of racial disparities in 30-day outcomes of patients that underwent colorectal resection. METHODS: Colon and rectal resections from 2008 to 2019 were reviewed retrospectively using the Veterans Affairs Surgical Quality Improvement Program database. Patients were categorized by race and ethnicity. Multivariable analysis was used to compare 30-day outcomes. Cases with "unknown/other/declined to answer" race/ethnicity were excluded. RESULTS: Thirty-six-thousand-nine-hundred-sixty-nine cases met inclusion criteria: 27,907 (75.5%) Caucasian, 6718 (18.2%) African American, 2047 (5.5%) Hispanic, and 290 (0.8%) Native American patients. There were no statistically significant differences in overall complication incidence or mortality between all cohorts. Compared to Caucasian race, African American patients had longer mean length of stay (10.7 days vs. 9.7 days; p < 0.001). Compared to Caucasian race, Hispanic patients had higher odds of pulmonary-specific complications (adjusted odds ratio with 95% confidence interval = 1.39 [1.17-1.64]; p < 0.001). CONCLUSIONS: The VHA provides the benefits of integrated healthcare and access, which may explain the improvements in racial disparities compared to existing literature. However, some racial disparities in clinical outcomes still persisted in this analysis. Further efforts beyond healthcare access are needed to mitigate disparities in colorectal surgery. CLASSIFICATIONS: [Outcomes]; [Database]; [Veterans]; [Colorectal Surgery]; [Morbidity]; [Mortality].


Assuntos
Cirurgia Colorretal , Prestação Integrada de Cuidados de Saúde , Disparidades em Assistência à Saúde , Humanos , Estudos Retrospectivos , Estados Unidos/epidemiologia , População Branca
4.
J Vasc Interv Radiol ; 33(3): 324-332.e2, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34923098

RESUMO

PURPOSE: To show that a deep learning (DL)-based, automated model for Lipiodol (Guerbet Pharmaceuticals, Paris, France) segmentation on cone-beam computed tomography (CT) after conventional transarterial chemoembolization performs closer to the "ground truth segmentation" than a conventional thresholding-based model. MATERIALS AND METHODS: This post hoc analysis included 36 patients with a diagnosis of hepatocellular carcinoma or other solid liver tumors who underwent conventional transarterial chemoembolization with an intraprocedural cone-beam CT. Semiautomatic segmentation of Lipiodol was obtained. Subsequently, a convolutional U-net model was used to output a binary mask that predicted Lipiodol deposition. A threshold value of signal intensity on cone-beam CT was used to obtain a Lipiodol mask for comparison. The dice similarity coefficient (DSC), mean squared error (MSE), center of mass (CM), and fractional volume ratios for both masks were obtained by comparing them to the ground truth (radiologist-segmented Lipiodol deposits) to obtain accuracy metrics for the 2 masks. These results were used to compare the model versus the threshold technique. RESULTS: For all metrics, the U-net outperformed the threshold technique: DSC (0.65 ± 0.17 vs 0.45 ± 0.22, P < .001) and MSE (125.53 ± 107.36 vs 185.98 ± 93.82, P = .005). The difference between the CM predicted and the actual CM was 15.31 mm ± 14.63 versus 31.34 mm ± 30.24 (P < .001), with lesser distance indicating higher accuracy. The fraction of volume present ([predicted Lipiodol volume]/[ground truth Lipiodol volume]) was 1.22 ± 0.84 versus 2.58 ± 3.52 (P = .048) for the current model's prediction and threshold technique, respectively. CONCLUSIONS: This study showed that a DL framework could detect Lipiodol in cone-beam CT imaging and was capable of outperforming the conventionally used thresholding technique over several metrics. Further optimization will allow for more accurate, quantitative predictions of Lipiodol depositions intraprocedurally.


Assuntos
Carcinoma Hepatocelular , Quimioembolização Terapêutica , Aprendizado Profundo , Neoplasias Hepáticas , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Tomografia Computadorizada de Feixe Cônico/métodos , Óleo Etiodado , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/terapia
5.
Sci Rep ; 10(1): 18026, 2020 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-33093524

RESUMO

Conventional transarterial chemoembolization (cTACE) is a guideline-approved image-guided therapy option for liver cancer using the radiopaque drug-carrier and micro-embolic agent Lipiodol, which has been previously established as an imaging biomarker for tumor response. To establish automated quantitative and pattern-based image analysis techniques of Lipiodol deposition on 24 h post-cTACE CT as biomarker for treatment response. The density of Lipiodol deposits in 65 liver lesions was automatically quantified using Hounsfield Unit thresholds. Lipiodol deposition within the tumor was automatically assessed for patterns including homogeneity, sparsity, rim, and peripheral deposition. Lipiodol deposition was correlated with enhancing tumor volume (ETV) on baseline and follow-up MRI. ETV on baseline MRI strongly correlated with Lipiodol deposition on 24 h CT (p < 0.0001), with 8.22% ± 14.59 more Lipiodol in viable than necrotic tumor areas. On follow-up, tumor regions with Lipiodol showed higher rates of ETV reduction than areas without Lipiodol (p = 0.0475) and increasing densities of Lipiodol enhanced this effect. Also, homogeneous (p = 0.0006), non-sparse (p < 0.0001), rim deposition within sparse tumors (p = 0.045), and peripheral deposition (p < 0.0001) of Lipiodol showed improved response. This technical innovation study showed that an automated threshold-based volumetric feature characterization of Lipiodol deposits is feasible and enables practical use of Lipiodol as imaging biomarker for therapeutic efficacy after cTACE.


Assuntos
Biomarcadores/análise , Carcinoma Hepatocelular/patologia , Quimioembolização Terapêutica/métodos , Meios de Contraste/análise , Óleo Etiodado/análise , Neoplasias Hepáticas/patologia , Tomografia Computadorizada por Raios X/métodos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/tratamento farmacológico , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento , Carga Tumoral
6.
Radiology ; 296(3): 575-583, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32633675

RESUMO

Background The immuno-metabolic interplay has gained interest for determining and targeting immunosuppressive tumor micro-environments that remain a barrier to current immuno-oncologic therapies in hepatocellular carcinoma. Purpose To develop molecular MRI tools to reveal resistance mechanisms to immuno-oncologic therapies caused by the immuno-metabolic interplay in a translational liver cancer model. Materials and Methods A total of 21 VX2 liver tumor-bearing New Zealand white rabbits were used between October 2018 and February 2020. Rabbits were divided into three groups. Group A (n = 3) underwent intra-arterial infusion of gadolinium 160 (160Gd)-labeled anti-human leukocyte antigen-DR isotope (HLA-DR) antibodies to detect antigen-presenting immune cells. Group B (n = 3) received rhodamine-conjugated superparamagnetic iron oxide nanoparticles (SPIONs) intravenously to detect macrophages. These six rabbits underwent 3-T MRI, including T1- and T2-weighted imaging, before and 24 hours after contrast material administration. Group C (n = 15) underwent extracellular pH mapping with use of MR spectroscopy. Of those 15 rabbits, six underwent conventional transarterial chemoembolization (TACE), four underwent conventional TACE with extracellular pH-buffering bicarbonate, and five served as untreated controls. MRI signal intensity distribution was validated by using immunohistochemistry staining of HLA-DR and CD11b, Prussian blue iron staining, fluorescence microscopy of rhodamine, and imaging mass cytometry (IMC) of gadolinium. Statistical analysis included Mann-Whitney U and Kruskal-Wallis tests. Results T1-weighted MRI with 160Gd-labeled antibodies revealed localized peritumoral ring enhancement, which corresponded to gadolinium distribution detected with IMC. T2-weighted MRI with SPIONs showed curvilinear signal intensity representing selective peritumoral deposition in macrophages. Extracellular pH-specific MR spectroscopy of untreated liver tumors showed acidosis (mean extracellular pH, 6.78 ± 0.09) compared with liver parenchyma (mean extracellular pH, 7.18 ± 0.03) (P = .008) and peritumoral immune cell exclusion. Normalization of tumor extracellular pH (mean, 6.96 ± 0.05; P = .02) using bicarbonate during TACE increased peri- and intratumoral immune cell infiltration (P = .002). Conclusion MRI in a rabbit liver tumor model was used to visualize resistance mechanisms mediated by the immuno-metabolic interplay that inform susceptibility and response to immuno-oncologic therapies, providing a therapeutic strategy to restore immune permissiveness in liver cancer. © RSNA, 2020 Online supplemental material is available for this article.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas Experimentais , Imageamento por Ressonância Magnética/métodos , Imagem Molecular/métodos , Animais , Anticorpos/administração & dosagem , Anticorpos/química , Anticorpos/metabolismo , Biomarcadores , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica , Meios de Contraste/administração & dosagem , Meios de Contraste/química , Meios de Contraste/farmacocinética , Gadolínio/administração & dosagem , Gadolínio/química , Gadolínio/farmacocinética , Fígado/diagnóstico por imagem , Fígado/patologia , Neoplasias Hepáticas Experimentais/diagnóstico por imagem , Neoplasias Hepáticas Experimentais/imunologia , Neoplasias Hepáticas Experimentais/metabolismo , Neoplasias Hepáticas Experimentais/terapia , Masculino , Coelhos , Microambiente Tumoral
7.
Clin Cancer Res ; 26(2): 428-438, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31582517

RESUMO

PURPOSE: To establish magnetic resonance (MR)-based molecular imaging paradigms for the noninvasive monitoring of extracellular pH (pHe) as a functional surrogate biomarker for metabolic changes induced by locoregional therapy of liver cancer. EXPERIMENTAL DESIGN: Thirty-two VX2 tumor-bearing New Zealand white rabbits underwent longitudinal imaging on clinical 3T-MRI and CT scanners before and up to 2 weeks after complete conventional transarterial chemoembolization (cTACE) using ethiodized oil (lipiodol) and doxorubicin. MR-spectroscopic imaging (MRSI) was employed for pHe mapping. Multiparametric MRI and CT were performed to quantify tumor enhancement, diffusion, and lipiodol coverage of the tumor posttherapy. In addition, incomplete cTACE with reduced chemoembolic doses was applied to mimic undertreatment and exploit pHe mapping to detect viable tumor residuals. Imaging findings were correlated with histopathologic markers indicative of metabolic state (HIF-1α, GLUT-1, and LAMP-2) and viability (proliferating cell nuclear antigen and terminal deoxynucleotidyl-transferase dUTP nick-end labeling). RESULTS: Untreated VX2 tumors demonstrated a significantly lower pHe (6.80 ± 0.09) than liver parenchyma (7.19 ± 0.03, P < 0.001). Upregulation of HIF-1α, GLUT-1, and LAMP-2 confirmed a hyperglycolytic tumor phenotype and acidosis. A gradual tumor pHe increase toward normalization similar to parenchyma was revealed within 2 weeks after complete cTACE, which correlated with decreasing detectability of metabolic markers. In contrast, pHe mapping after incomplete cTACE indicated both acidic viable residuals and increased tumor pHe of treated regions. Multimodal imaging revealed durable tumor devascularization immediately after complete cTACE, gradually increasing necrosis, and sustained lipiodol coverage of the tumor. CONCLUSIONS: MRSI-based pHe mapping can serve as a longitudinal monitoring tool for viable tumors. As most liver tumors are hyperglycolytic creating microenvironmental acidosis, therapy-induced normalization of tumor pHe may be used as a functional biomarker for positive therapeutic outcome.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Biomarcadores Tumorais/análise , Glicólise , Neoplasias Hepáticas Experimentais/patologia , Imagem Molecular/métodos , Microambiente Tumoral , Animais , Doxorrubicina/administração & dosagem , Óleo Etiodado/administração & dosagem , Concentração de Íons de Hidrogênio , Neoplasias Hepáticas Experimentais/diagnóstico por imagem , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Neoplasias Hepáticas Experimentais/metabolismo , Imageamento por Ressonância Magnética/métodos , Masculino , Coelhos
8.
JAMA Netw Open ; 2(7): e197249, 2019 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-31339541

RESUMO

Importance: The use of medical imaging has sharply increased over the last 2 decades. Imaging rates during pregnancy have not been quantified in a large, multisite study setting. Objective: To evaluate patterns of medical imaging during pregnancy. Design, Setting, and Participants: A retrospective cohort study was performed at 6 US integrated health care systems and in Ontario, Canada. Participants included pregnant women who gave birth to a live neonate of at least 24 weeks' gestation between January 1, 1996, and December 31, 2016, and who were enrolled in the health care system for the entire pregnancy. Exposures: Computed tomography (CT), magnetic resonance imaging, conventional radiography, angiography and fluoroscopy, and nuclear medicine. Main Outcomes and Measures: Imaging rates per pregnancy stratified by country and year of child's birth. Results: A total of 3 497 603 pregnancies in 2 211 789 women were included. Overall, 26% of pregnancies were from US sites. Most (92%) were in women aged 20 to 39 years, and 85% resulted in full-term births. Computed tomography imaging rates in the United States increased from 2.0 examinations/1000 pregnancies in 1996 to 11.4/1000 pregnancies in 2007, remained stable through 2010, and decreased to 9.3/1000 pregnancies by 2016, for an overall increase of 3.7-fold. Computed tomography rates in Ontario, Canada, increased more gradually by 2.0-fold, from 2.0/1000 pregnancies in 1996 to 6.2/1000 pregnancies in 2016, which was 33% lower than in the United States. Overall, 5.3% of pregnant women in US sites and 3.6% in Ontario underwent imaging with ionizing radiation, and 0.8% of women at US sites and 0.4% in Ontario underwent CT. Magnetic resonance imaging rates increased steadily from 1.0/1000 pregnancies in 1996 to 11.9/1000 pregnancies in 2016 in the United States and from 0.5/1000 pregnancies in 1996 to 9.8/1000 pregnancies in 2016 in Ontario, surpassing CT rates in 2013 in the United States and in 2007 in Ontario. In the United States, radiography rates doubled from 34.5/1000 pregnancies in 1996 to 72.6/1000 pregnancies in 1999 and then decreased to 47.6/1000 pregnancies in 2016; rates in Ontario slowly increased from 36.2/1000 pregnancies in 1996 to 44.7/1000 pregnancies in 2016. Angiography and fluoroscopy and nuclear medicine use rates were low (5.2/1000 pregnancies), but in most years, higher in Ontario than the United States. Imaging rates were highest for women who were younger than 20 years or aged 40 years or older, gave birth preterm, or were black, Native American, or Hispanic (US data only). Considering advanced imaging only, chest imaging of pregnant women was more likely to use CT in the United States and nuclear medicine imaging in Ontario. Conclusions and Relevance: The use of CT during pregnancy substantially increased in the United States and Ontario over the past 2 decades. Imaging rates during pregnancy should be monitored to avoid unnecessary exposure of women and fetuses to ionizing radiation.


Assuntos
Diagnóstico por Imagem/estatística & dados numéricos , Adulto , Diagnóstico por Imagem/classificação , Feminino , Idade Gestacional , Humanos , Imageamento por Ressonância Magnética/estatística & dados numéricos , Ontário , Gravidez , Cuidado Pré-Natal/estatística & dados numéricos , Radiação Ionizante , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Estados Unidos , Adulto Jovem
9.
J Vasc Interv Radiol ; 29(6): 850-857.e1, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29548875

RESUMO

PURPOSE: To use magnetic resonance (MR) imaging and clinical patient data to create an artificial intelligence (AI) framework for the prediction of therapeutic outcomes of transarterial chemoembolization by applying machine learning (ML) techniques. MATERIALS AND METHODS: This study included 36 patients with hepatocellular carcinoma (HCC) treated with transarterial chemoembolization. The cohort (age 62 ± 8.9 years; 31 men; 13 white; 24 Eastern Cooperative Oncology Group performance status 0, 10 status 1, 2 status 2; 31 Child-Pugh stage A, 4 stage B, 1 stage C; 1 Barcelona Clinic Liver Cancer stage 0, 12 stage A, 10 stage B, 13 stage C; tumor size 5.2 ± 3.0 cm; number of tumors 2.6 ± 1.1; and 30 conventional transarterial chemoembolization, 6 with drug-eluting embolic agents). MR imaging was obtained before and 1 month after transarterial chemoembolization. Image-based tumor response to transarterial chemoembolization was assessed with the use of the 3D quantitative European Association for the Study of the Liver (qEASL) criterion. Clinical information, baseline imaging, and therapeutic features were used to train logistic regression (LR) and random forest (RF) models to predict patients as treatment responders or nonresponders under the qEASL response criterion. The performance of each model was validated using leave-one-out cross-validation. RESULTS: Both LR and RF models predicted transarterial chemoembolization treatment response with an overall accuracy of 78% (sensitivity 62.5%, specificity 82.1%, positive predictive value 50.0%, negative predictive value 88.5%). The strongest predictors of treatment response included a clinical variable (presence of cirrhosis) and an imaging variable (relative tumor signal intensity >27.0). CONCLUSIONS: Transarterial chemoembolization outcomes in patients with HCC may be predicted before procedures by combining clinical patient data and baseline MR imaging with the use of AI and ML techniques.


Assuntos
Antineoplásicos/administração & dosagem , Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Doxorrubicina/administração & dosagem , Óleo Etiodado/administração & dosagem , Neoplasias Hepáticas/terapia , Aprendizado de Máquina , Imageamento por Ressonância Magnética , Adulto , Idoso , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Meios de Contraste/administração & dosagem , Feminino , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Valor Preditivo dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Resultado do Tratamento
10.
Clin Cancer Res ; 14(6): 1804-13, 2008 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-18347183

RESUMO

PURPOSE: To determine if hyaluronan oligomers (o-HA) antagonize the malignant properties of glioma cells and treatment-resistant glioma side population (SP) cells in vitro and in vivo. EXPERIMENTAL DESIGN: A single intratumoral injection of o-HA was given to rats bearing spinal cord gliomas 7 days after engraftment of C6 glioma cells. At 14 days, spinal cords were evaluated for tumor size, invasive patterns, proliferation, apoptosis, activation of Akt, and BCRP expression. C6SP were isolated by fluorescence-activated cell sorting and tested for the effects of o-HA on BCRP expression, activation of Akt and epidermal growth factor receptor, drug resistance, and glioma growth in vivo. RESULTS: o-HA treatment decreased tumor cell proliferation, increased apoptosis, and down-regulated activation of Akt and the expression of BCRP. o-HA treatment of C6SP inhibited activation of epidermal growth factor receptor and Akt, decreased BCRP expression, and increased methotrexate cytotoxicity. In vivo, o-HA also suppressed the growth of gliomas that formed after engraftment of C6 or BCRP+ C6SP cells, although most C6SP cells lost their expression of BCRP when grown in vivo. Interestingly, the spinal cord gliomas contained many BCRP+ cells that were not C6 or C6SP cells but that expressed nestin and/or CD45; o-HA treatment significantly decreased the recruitment of these BCRP+ progenitor cells into the engrafted gliomas. CONCLUSIONS: o-HA suppress glioma growth in vivo by enhancing apoptosis, down-regulating key cell survival mechanisms, and possibly by decreasing recruitment of host-derived BCRP+ progenitor cells. Thus, o-HA hold promise as a new biological therapy to inhibit HA-mediated malignant mechanisms in glioma cells and treatment-resistant glioma stem cells.


Assuntos
Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Glioma/tratamento farmacológico , Ácido Hialurônico/antagonistas & inibidores , Ácido Hialurônico/uso terapêutico , Células-Tronco Neoplásicas/efeitos dos fármacos , Neoplasias da Medula Espinal/tratamento farmacológico , Neoplasias da Medula Espinal/metabolismo , Animais , Antineoplásicos/uso terapêutico , Sistemas de Liberação de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Glioma/metabolismo , Receptores de Hialuronatos/efeitos dos fármacos , Receptores de Hialuronatos/metabolismo , Ácido Hialurônico/metabolismo , Transplante de Neoplasias , Células-Tronco Neoplásicas/metabolismo , Polímeros/uso terapêutico , Ligação Proteica/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Células Tumorais Cultivadas
11.
Mol Cell Proteomics ; 7(6): 1077-88, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18258654

RESUMO

Recently protein kinases have emerged as some of the most promising drug targets; and therefore, pharmaceutical strategies have been developed to inhibit kinases in the treatment of a variety of diseases. CK2 is a serine/threonine-protein kinase that has been implicated in a number of cellular processes, including maintenance of cell viability, protection of cells from apoptosis, and tumorigenesis. Elevated CK2 activity has been established in a number of cancers where it was shown to promote tumorigenesis via the regulation of the activity of various oncogenes and tumor suppressor proteins. Consequently the development of CK2 inhibitors has been ongoing in preclinical studies, resulting in the generation of a number of CK2-directed compounds. In the present study, an unbiased evaluation of CK2 inhibitors 4,5,6,7-tetrabromo-1H-benzotriazole (TBB), 4,5,6,7-tetrabromo-1H-benzimidazole (TBBz), and 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole (DMAT) was carried out to elucidate the mechanism of action as well as inhibitor specificity of these compounds. Utilizing a chemoproteomics approach in conjunction with inhibitor-resistant mutant studies, CK2alpha and CK2alpha' were identified as bona fide targets of TBB, TBBz, and DMAT in cells. However, inhibitor-specific cellular effects were observed indicating that the structurally related compounds had unique biological properties, suggesting differences in inhibitor specificity. Rescue experiments utilizing inhibitor-resistant CK2 mutants were unable to rescue the apoptosis associated with TBBz and DMAT treatment, suggesting the inhibitors had off-target effects. Exploitation of an unbiased chemoproteomics approach revealed a number of putative off-target inhibitor interactions, including the discovery of a novel TBBz and DMAT (but not TBB) target, the detoxification enzyme quinone reductase 2 (QR2). The results described in the present study provide insight into the molecular mechanism of action of the inhibitors as well as drug specificity that will assist in the development of more specific next generation CK2 inhibitors.


Assuntos
Caseína Quinase II/antagonistas & inibidores , Caseína Quinase II/metabolismo , Inibidores Enzimáticos/farmacologia , Regulação Enzimológica da Expressão Gênica , Benzimidazóis , Química Farmacêutica/métodos , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Humanos , Concentração Inibidora 50 , Cinética , Modelos Químicos , Mutação , Proteômica/métodos , Triazóis/farmacologia , Proteínas Supressoras de Tumor/metabolismo
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