RESUMO
Due to the poor prognosis of advanced metastatic melanoma, it is crucial to find early biomarkers that help identify which melanomas will metastasize. By comparing the gene expression data from primary and cutaneous melanoma samples from The Cancer Genome Atlas (TCGA), we identified GPC6 among a set of genes whose expression levels can distinguish between primary melanoma and regional cutaneous/subcutaneous metastases. Glypicans are thought to play a role in tumor growth by regulating the signaling pathways of Wnt, Hedgehogs, fibroblast growth factors (FGFs), and bone morphogenetic proteins (BMPs). We showed that GPC6 expression was up-regulated in a melanoma cell line compared to normal melanocytes and in metastatic melanoma compared to primary melanoma. Furthermore, GPC6 expression was positively correlated with genes largely involved in cell adhesion and migration in both melanoma samples and in RNA-seq samples from other TCGA tumors. Our results suggest that GPC6 may play a role in tumor metastatic progression. In TCGA melanoma samples, we also showed that GPC6 expression was negatively correlated with miR-509-3p, which has previously been shown to function as a tumor suppressor in various cancer cell lines. We overexpressed miR-509-3p in A375 melanoma cells and showed that GPC6 expression was significantly suppressed. This result suggested that GPC6 was a putative target of miR-509-3p in melanoma. Together, our findings identified GPC6 as an early biomarker for melanoma metastatic progression, one that can be regulated by miR-509-3p.
Assuntos
Biomarcadores Tumorais/biossíntese , Regulação Neoplásica da Expressão Gênica , Glipicanas/biossíntese , Melanoma/metabolismo , Proteínas de Neoplasias/biossíntese , Neoplasias Cutâneas/metabolismo , Regulação para Cima , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Feminino , Glipicanas/genética , Humanos , Masculino , Melanoma/genética , Melanoma/patologia , MicroRNAs/biossíntese , MicroRNAs/genética , Metástase Neoplásica , Proteínas de Neoplasias/genética , RNA Neoplásico/biossíntese , RNA Neoplásico/genética , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Melanoma Maligno CutâneoRESUMO
PURPOSE OF REVIEW: Uterine fibroids are common benign tumors of women in the USA and worldwide, yet the biological nature and pathogenesis of these tumors remain largely unknown. This review presents our view of the stages in the life cycle of a subset of uterine fibroid myocytes, introduces hypothetical concepts and morphological data to explain these changes, and relates these changes in individual myocytes to the phases of fibroid tumor development. RECENT FINDINGS: The observations gained from light and electron microscopic, immunohistochemical, and morphometric studies in our laboratory have led to the hypothesis that fibroid changes over time may relate to the excessive production of collagen by phenotypically transformed myocytes. This accumulation of collagen results in decreased microvessel density, followed by myocyte injury and atrophy, with eventual senescence and involution through ischemic cellular degeneration and inanition. SUMMARY: Uterine leiomyomas, or fibroids, are characterized by two histologic features-proliferation of myocytes and production of an extracellular collagenous matrix. In the larger tumors, the collagenous matrix is often abundant. Within those regions in which the accumulating collagen is excessive, the myocytes are progressively separated from their blood supply, resulting in myocyte atrophy and eventually cell death. It is within these hypocellular, hyalinized areas that the complete lifecycle of the fibroid myocyte is realized. It begins with the phenotypic transformation of a contractile cell to one characterized by proliferation and collagen synthesis, progresses through an intermediate stage of atrophy related to interstitial ischemia, and eventuates in cell death due to inanition. Lastly, resorption of inanotic cells appears to occur by a non-phagocytic, presumably enzymatic process of degradation and recycling that we refer to as reclamation.
RESUMO
Phenobarbital, a nongenotoxic hepatocarcinogen, induces hepatic proliferation and promotes development of hepatocellular carcinoma (HCC) in rodents. Nuclear receptor constitutive active/androstane receptor (NR1I3/CAR) regulates the induction and promotion activities of phenobarbital. Here, it is demonstrated that phenobarbital treatment results in dephosphorylation of a tumor suppressor p38 MAPK in the liver of C57BL/6 and C3H/HeNCrlBR mice. The molecular mechanism entails CAR binding and inhibition of the growth arrest and DNA-damage-inducible 45 beta (GADD45B)-MAPK kinase 6 (MKK6) scaffold to repress phosphorylation of p38 MAPK. Phenobarbital-induced hepatocyte proliferation, as determined by BrdUrd incorporation, was significantly reduced in both male and female livers of GADD45B knockout (KO) mice compared with the wild-type mice. The phenobarbital-induced proliferation continued until 48 hours after phenobarbital injection in only the C57BL/6 males, but neither in males of GADD45B KO mice nor in females of C57BL/6 and GADD45B KO mice. Thus, these data reveal nuclear receptor CAR interacts with GADD45B to repress p38 MAPK signaling and elicit hepatocyte proliferation in male mice.Implications: This GADD45B-regulated male-predominant proliferation can be expanded as a phenobarbital promotion signal of HCC development in future studies.Visual Overview: http://mcr.aacrjournals.org/content/molcanres/16/8/1309/F1.large.jpg Mol Cancer Res; 16(8); 1309-18. ©2018 AACR.
Assuntos
Anticonvulsivantes/efeitos adversos , Antígenos de Diferenciação/genética , Proliferação de Células/efeitos dos fármacos , Fígado/patologia , Fenobarbital/efeitos adversos , Receptores Citoplasmáticos e Nucleares/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Antígenos de Diferenciação/metabolismo , Receptor Constitutivo de Androstano , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Asthma is associated with exposure to a wide variety of allergens and adjuvants. The extent to which overlap exists between the cellular and molecular mechanisms triggered by these various agents is poorly understood, but it might explain the differential responsiveness of patients to specific therapies. In particular, it is unclear why some, but not all, patients benefit from blockade of TNF. Here, we characterized signaling pathways triggered by distinct types of adjuvants during allergic sensitization. Mice sensitized to an innocuous protein using TLR ligands or house dust extracts as adjuvants developed mixed eosinophilic and neutrophilic airway inflammation and airway hyperresponsiveness (AHR) following allergen challenge, whereas mice sensitized using proteases as adjuvants developed predominantly eosinophilic inflammation and AHR. TLR ligands, but not proteases, induced TNF during allergic sensitization. TNF signaled through airway epithelial cells to reprogram them and promote Th2, but not Th17, development in lymph nodes. TNF was also required during the allergen challenge phase for neutrophilic and eosinophilic inflammation. In contrast, TNF was dispensable for allergic airway disease in a protease-mediated model of asthma. These findings might help to explain why TNF blockade improves lung function in only some patients with asthma.
Assuntos
Hipersensibilidade/metabolismo , Inflamação/fisiopatologia , Hipersensibilidade Respiratória/metabolismo , Receptores Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/fisiologia , Alérgenos , Animais , Asma/metabolismo , Asma/fisiopatologia , Hiper-Reatividade Brônquica/fisiopatologia , Diferenciação Celular , Citocinas/metabolismo , Modelos Animais de Doenças , Eosinófilos/citologia , Hipersensibilidade/fisiopatologia , Interleucina-17/metabolismo , Ligantes , Pulmão/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neutrófilos/citologia , Ovalbumina/metabolismo , Hipersensibilidade Respiratória/fisiopatologia , Transdução de Sinais , Células Th17/citologia , Células Th2/citologiaRESUMO
Inhalation of diacetyl vapors by workers has been associated with obliterative bronchiolitis (OB), a poorly understood fibroproliferative disease of the small airways. Significant insights into the pathogenesis of OB have been obtained through the use of a rat model. Inhalation exposure of rats to diacetyl or 2,3-pentanedione, a related flavoring agent, can cause severe injury to the airway epithelium and underlying basement membrane. Repeated exposure to diacetyl or 2,3-pentanedione leads to aberrant repair, fibroproliferation and partial to complete occlusion of the airway lumen. Fibroproliferative lesions in rat airways were found to include both intraluminal polyps and circumferential intramural lesions. Intraluminal polyps have been observed to form secondary attachments spanning the airway lumen causing increasing obstruction. These airway lesions in rats are accompanied by inflammation in the form of peribronchial and perivascular infiltrates of lymphocytes, eosinophils and neutrophils. Diacetyl-induced OB lesions in the rat are similar to OB lesions in humans and provide a good model for studying the pathogenesis of this disease.
Assuntos
Bronquiolite Obliterante/induzido quimicamente , Diacetil/toxicidade , Aromatizantes/toxicidade , Exposição por Inalação/efeitos adversos , Pentanonas/toxicidade , Animais , Membrana Basal/efeitos dos fármacos , Membrana Basal/patologia , Bronquiolite Obliterante/patologia , Diacetil/administração & dosagem , Modelos Animais de Doenças , Aromatizantes/administração & dosagem , Humanos , Masculino , Exposição Ocupacional/efeitos adversos , Pentanonas/administração & dosagem , Ratos , Ratos Wistar , Mucosa Respiratória/efeitos dos fármacos , Mucosa Respiratória/patologia , Especificidade da EspécieRESUMO
Tristetraprolin (TTP) acts by binding to AU-rich elements in certain mRNAs, such as tumor necrosis factor (TNF) mRNA, and increasing their decay rates. TTP knockout mice exhibit a profound inflammatory syndrome that is largely due to increased TNF levels. Although TTP's effects on gene expression have been well studied in cultured cells, little is known about its functions in intact tissues. We performed deep RNA sequencing on spleens from TTP knockout mice that were also deficient in both TNF receptors ("triple knockout" mice) to remove the secondary effects of excess TNF activity. To help identify posttranscriptionally regulated transcripts, we also compared changes in mature mRNA levels to levels of transiently expressed pre-mRNA. In the triple knockout spleens, levels of 3,014 transcripts were significantly affected by 1.5-fold or more, but only a small fraction exhibited differential mRNA/pre-mRNA changes suggestive of increased mRNA stability. Transferrin receptor mRNA, which contains two highly conserved potential TTP binding sites, was significantly upregulated relative to its pre-mRNA. This was reflected in increased transferrin receptor expression and increased splenic iron/hemosiderin deposition. Our results suggest that TTP deficiency has profound effects on the splenic transcriptome, even in the absence of secondary increases in TNF activity.
Assuntos
Receptores Tipo II do Fator de Necrose Tumoral/genética , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Baço/fisiologia , Transcriptoma , Tristetraprolina/genética , Animais , Sítios de Ligação , Éxons , Regulação da Expressão Gênica , Íntrons , Masculino , Camundongos Knockout , RNA Mensageiro , Receptores da Transferrina/genética , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Receptores Tipo II do Fator de Necrose Tumoral/metabolismo , Análise de Sequência de RNA , Baço/imunologia , Tristetraprolina/metabolismoRESUMO
Primary and metastatic melanoma tumors share the same cell origin, making it challenging to identify genomic biomarkers that can differentiate them. Primary tumors themselves can be heterogeneous, reflecting ongoing genomic changes as they progress toward metastasizing. We developed a computational method to explore this heterogeneity and to predict metastatic progression of the primary tumors. We applied our method separately to gene expression and to microRNA (miRNA) expression data from ~450 primary and metastatic skin cutaneous melanoma (SKCM) samples from the Cancer Genome Atlas (TCGA). Metastatic progression scores from RNA-seq data were significantly associated with clinical staging of patients' lymph nodes, whereas scores from miRNA-seq data were significantly associated with Clark's level. The loss of expression of many characteristic epithelial lineage genes in primary SKCM tumor samples was highly correlated with predicted progression scores. We suggest that those genes/miRNAs might serve as putative biomarkers for SKCM metastatic progression.
Assuntos
Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Melanoma/genética , Melanoma/patologia , Ontologia Genética , Genes Neoplásicos , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Metástase Neoplásica , Prognóstico , Análise de Sequência de RNA , Neoplasias Cutâneas , Melanoma Maligno CutâneoRESUMO
Obliterative bronchiolitis (OB) is an irreversible lung disease characterized by progressive fibrosis in the small airways with eventual occlusion of the airway lumens. OB is most commonly associated with lung transplant rejection; however, OB has also been diagnosed in workers exposed to artificial butter flavoring (ABF) vapors. Research has been limited by the lack of an adequate animal model of OB, and as a result the mechanism(s) is unclear and there are no effective treatments for this condition. Exposure of rats to the ABF component, 2,3-pentanedione (PD) results in airway lesions that are histopathologically similar to those in human OB. We used this animal model to evaluate changes in gene expression in the distal bronchi of rats with PD-induced OB. Male Wistar Han rats were exposed to 200 ppm PD or air 6 h/d, 5 d/wk for 2-wks. Bronchial tissues were laser microdissected from serial sections of frozen lung. In exposed lungs, both fibrotic and non-fibrotic airways were collected. Following RNA extraction and microarray analysis, differential gene expression was evaluated. In non-fibrotic bronchi of exposed rats, 4683 genes were significantly altered relative to air-exposed controls with notable down-regulation of many inflammatory cytokines and chemokines. In contrast, in fibrotic bronchi, 3807 genes were significantly altered with a majority of genes being up-regulated in affected pathways. Tgf-ß2 and downstream genes implicated in fibrosis were significantly up-regulated in fibrotic lesions. Genes for collagens and extracellular matrix proteins were highly up-regulated. In addition, expression of genes for peptidases and peptidase inhibitors were significantly altered, indicative of the tissue remodeling that occurs during airway fibrosis. Our data provide new insights into the molecular mechanisms of OB. This new information is of potential significance with regard to future therapeutic targets for treatment.
Assuntos
Brônquios/metabolismo , Bronquiolite Obliterante/patologia , Regulação para Baixo/efeitos dos fármacos , Pentanonas/toxicidade , Regulação para Cima/efeitos dos fármacos , Animais , Brônquios/patologia , Bronquiolite Obliterante/induzido quimicamente , Bronquiolite Obliterante/genética , Modelos Animais de Doenças , Fibrose/patologia , Imuno-Histoquímica , Exposição por Inalação , Masculino , Análise de Componente Principal , RNA/isolamento & purificação , RNA/metabolismo , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Fator de Crescimento Transformador beta2/genética , Fator de Crescimento Transformador beta2/metabolismoRESUMO
Cytochrome P450 (CYP) 4A and 4F enzymes metabolize arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE). Although CYP4A-derived 20-HETE is known to have prohypertensive and proangiogenic properties, the effects of CYP4F-derived metabolites are not well characterized. To investigate the role of CYP4F2 in vascular disease, we generated mice with endothelial expression of human CYP4F2 (Tie2-CYP4F2-Tr). LC/MS/MS analysis revealed 2-foldincreases in 20-HETE levels in tissues and endothelial cells (ECs), relative to wild-type (WT) controls. Tie2-CYP4F2-Tr ECs demonstrated increases in growth (267.1 ± 33.4 vs. 205.0 ± 13% at 48 h) and tube formation (7.7 ± 1.1 vs. 1.6 ± 0.5 tubes/field) that were 20-HETE dependent and associated with up-regulation of prooxidant NADPH oxidase and proangiogenic VEGF. Increases in VEGF and NADPH oxidase levels were abrogated by inhibitors of NADPH oxidase and MAPK, respectively, suggesting the possibility of crosstalk between pathways. Interestingly, IL-6 levels in Tie2-CYP4F2-Tr mice (18.6 ± 2.7 vs. 7.9 ± 2.7 pg/ml) were up-regulated via NADPH oxidase- and 20-HETE-dependent mechanisms. Although Tie2-CYP4F2-Tr aortas displayed increased vasoconstriction, vasorelaxation and blood pressure were unchanged. Our findings indicate that human CYP4F2 significantly increases 20-HETE production, CYP4F2-derived 20-HETE mediates EC proliferation and angiogenesis via VEGF- and NADPH oxidase-dependent manners, and the Tie2-CYP4F2-Tr mouse is a novel model for examining the pathophysiological effects of CYP4F2-derived 20-HETE in the vasculature.-Cheng, J., Edin, M. L., Hoopes, S. L., Li, H., Bradbury, J. A., Graves, J. P., DeGraff, L. M., Lih, F. B., Garcia, V., Shaik, J. S. B., Tomer, K. B., Flake, G. P., Falck, J. R., Lee, C. R., Poloyac, S. M., Schwartzman, M. L., Zeldin, D. C. Vascular characterization of mice with endothelial expression of cytochrome P450 4F2.
Assuntos
Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Células Endoteliais/metabolismo , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Animais , Pressão Sanguínea/genética , Células Cultivadas , Família 4 do Citocromo P450 , Citocinas/genética , Citocinas/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Inflamação/genética , Inflamação/metabolismo , Masculino , Camundongos , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NADPH Oxidases/genética , NADPH Oxidases/metabolismo , Estresse Oxidativo/genética , Receptores de Fatores de Crescimento do Endotélio Vascular/genética , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismo , Regulação para Cima/genética , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
We propose, and offer evidence to support, the concept that many uterine leiomyomas pursue a self-limited life cycle. This cycle can be arbitrarily divided on the basis of morphologic assessment of the collagen content into 4 phases: (1) proliferation, (2) proliferation and synthesis of collagen, (3) proliferation, synthesis of collagen, and early senescence, and (4) involution. Involution occurs as a result of both vascular and interstitial ischemia. Interstitial ischemia is the consequence of the excessive elaboration of collagen, resulting in reduced microvascular density, increased distance between myocytes and capillaries, nutritional deprivation, and myocyte atrophy. The end stage of this process is an involuted tumor with a predominance of collagen, little to no proliferative activity, myocyte atrophy, and myocyte cell death. Since many of the dying cells exhibit light microscopic and ultrastructural features that appear distinct from either necrosis or apoptosis, we refer to this process as inanosis, because it appears that nutritional deprivation, or inanition, is the underlying cause of cell death. The disposal of myocytes dying by inanosis also differs in that there is no phagocytic reaction, but rather an apparent dissolution of the cell, which might be viewed as a process of reclamation as the molecular contents are reclaimed and recycled.
RESUMO
Based upon our morphologic observations, we hypothesize and also provide morphometric evidence for the occurrence of progressive developmental changes in many uterine fibroids, which can be arbitrarily divided into 4 phases. These developmental phases are related to the ongoing production of extracellular collagenous matrix, which eventually exceeds the degree of angiogenesis, resulting in the progressive separation of myocytes from their blood supply and a condition of interstitial ischemia. The consequence of this process of slow ischemia with nutritional and oxygen deprivation is a progressive myocyte atrophy (or inanition), culminating in cell death, a process that we refer to as inanosis. The studies presented here provide quantitative and semiquantitative evidence to support the concept of the declining proliferative activity as the collagenous matrix increases and the microvascular density decreases.
RESUMO
Exposure to estrogen-mimicking chemicals during critical periods of development, such as infancy, may have adverse effects. However, these effects can be difficult to characterize in most epidemiologic studies. For example, growth of reproductive organs may be susceptible to estrogenic chemicals, but measuring it requires skilled ultrasound examination; timing of pubertal onset may be altered, but observing it requires long-term follow up. To address the need for a simple marker of response to estrogenic exposures in infants, we propose a novel application of a classic marker of estrogen response in adult women: cytological evaluation of urogenital epithelial cells. In this cross-sectional study of 34 female and 41 male infants, we demonstrate that epithelial cells can be obtained from swabs of the vaginal introitus (females) and urethral meatus (males), as well as from spun urine, and that these cells respond to differential estrogenic conditions, as indicated by the relative abundance of the superficial epithelial cell type. To model varying estrogen exposure, we sampled from infants who were either newborn (highly exposed to maternal estrogens), or 12 weeks old (12 W) (negligibly exposed to estrogen). Newborns had a higher percentage of superficial cells (%S), as compared to 12 W (mean ± standard error: 8.3 ± 1.8 vs. 0.9 ± 0.2) (p < 0.01), consistent with an estrogen response. This difference in %S from newborn to 12 W was observed similarly for swab (-7.6 ± 1.7) and urine (-7.3 ± 2.6) specimens and for males (-9.6 ± 2.9) and females (-5.2 ± 2.1). Examination of urogenital epithelial cells can successfully demonstrate estrogen response in both sexes, using cell specimens collected from either swab or urine sampling. In future studies, this simple, non-invasive method may be applied to assess whether estrogen-mimicking chemicals produce an estrogenic response in infants.
Assuntos
Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Estrogênios/farmacologia , Sistema Urogenital/citologia , Biomarcadores , Feminino , Humanos , Lactente , Recém-Nascido , MasculinoRESUMO
Propargyl alcohol (PA) is a high production volume chemical used in synthesis of many industrial chemicals and agricultural products. Despite the potential for prolonged or accidental exposure to PA in industrial settings, the toxicity potential of PA was not well characterized. To address the knowledge gaps relevant to the toxicity profile of PA, the National Toxicology Program (NTP) conducted 2-week, 14-week and 2-year studies in male and female F344/N rats and B6C3F1/N mice. For the 2-week inhalation study, the rats and mice were exposed to 0, 31.3, 62.5, 125, 250 or 500ppm. Significant mortality was observed in both rats and mice exposed to ≥125ppm of PA. The major target organ of toxicity in both mice and rats was the liver with exposure-related histopathological changes (250 and 500ppm). Based on the decreased survival in the 2-week study, the rats and mice were exposed to 0, 4, 8, 16, 32 or 64ppm of PA in the 14-week study. No treatment-related mortality was observed. Mean body weights of male (≥8ppm) and female mice (32 and 64ppm) were significantly decreased (7-16%). Histopathological changes were noted in the nasal cavity, and included suppurative inflammation, squamous metaplasia, hyaline droplet accumulation, olfactory epithelium atrophy, and necrosis. In the 2-year inhalation studies, the rats were exposed to 0, 16, 32 and 64ppm of PA and the mice were exposed to 0, 8, 16 and 32ppm of PA. Survival of male rats was significantly reduced (32 and 64ppm). Mean body weights of 64ppm male rats were significantly decreased relative to the controls. Both mice and rats showed a spectrum of non-neoplastic changes in the nose. Increased neoplastic incidences of nasal respiratory/transitional epithelial adenoma were observed in both rats and mice. The incidence of mononuclear cell leukemia was significantly increased in male rats and was considered to be treatment-related. In conclusion, the key findings from this study indicated that the nose was the primary target organ of toxicity for PA. Long term inhalation exposure to PA led to nonneoplastic changes in the nose, and increased incidences of respiratory/transitional epithelial adenomas in both mice and rats. Increased incidences of harderian gland adenoma may also have been related to exposure to PA in male mice.
Assuntos
Alcinos/toxicidade , Carcinógenos , Propanóis/toxicidade , Adenoma/induzido quimicamente , Adenoma/patologia , Alcinos/administração & dosagem , Animais , Câmaras de Exposição Atmosférica , Testes de Carcinogenicidade , Feminino , Cartilagem Hialina/efeitos dos fármacos , Inflamação/patologia , Exposição por Inalação , Estimativa de Kaplan-Meier , Leucemia/induzido quimicamente , Leucemia/epidemiologia , Masculino , Camundongos , Camundongos Endogâmicos , Neoplasias/induzido quimicamente , Neoplasias/patologia , Exposição Ocupacional , Propanóis/administração & dosagem , Ratos , Ratos Endogâmicos F344 , Neoplasias do Sistema Respiratório/induzido quimicamente , Neoplasias do Sistema Respiratório/patologia , Caracteres Sexuais , Análise de SobrevidaRESUMO
Using a mouse skin tumor model, we reported previously that cyclooxygenase-2 (COX-2) deficiency reduced papilloma formation. However, this model did not differentiate between the effects of systemic COX-2-deficiency and keratinocyte-specific COX-2 deficiency on tumor formation. To determine whether keratinocyte-specific COX-2 deficiency reduced papilloma formation, v-H-ras-transformed COX-2+/+ and COX-2-/- keratinocytes were grafted onto nude mice and tumor development was compared. Transformed COX-2+/+ and COX-2-/- keratinocytes expressed similar levels of H-ras, epidermal growth factor receptor and phospho-extracellular signal-regulated kinase 1/2 in vitro; and COX-2-deficiency did not reduce uninfected or v-H-ras infected keratinocyte replication. In contrast, tumors arising from grafted transformed COX-2+/+ and COX-2-/- keratinocytes expressed similar levels of H-ras, but COX-2 deficiency reduced phospho-extracellular signal-regulated kinase 1/2 and epidermal growth factor receptor levels 50-60% and tumor volume by 80% at 3 weeks. Two factors appeared to account for the reduced papilloma size. First, papillomas derived from COX-2-/- keratinocytes showed about 70% decreased proliferation, as measured by bromodeoxyuridine incorporation, compared with papillomas derived from COX-2+/+ keratinocytes. Second, keratin 1 immunostaining of papillomas indicated that COX-2-/- keratinocytes prematurely initiated terminal differentiation. Differences in the levels of apoptosis and vascularization did not appear to be contributing factors as their levels were similar in tumors derived from COX-2-/- and COX-2+/+ keratinocytes. Overall, the data are in agreement with our previous observations that decreased papilloma number and size on COX-2-/- mice resulted from reduced keratinocyte proliferation and accelerated keratinocyte differentiation. Furthermore, the data indicate that deficiency/inhibition of COX-2 in the initiated keratinocyte is an important determinant of papilloma forming ability.
Assuntos
Transformação Celular Neoplásica/patologia , Ciclo-Oxigenase 2/fisiologia , Queratinócitos/patologia , Neovascularização Patológica , Papiloma/etiologia , Neoplasias Cutâneas/etiologia , Animais , Apoptose , Western Blotting , Transformação Celular Neoplásica/genética , Células Cultivadas , Técnicas Imunoenzimáticas , Queratinócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Nus , Papiloma/enzimologia , Papiloma/patologia , Neoplasias Cutâneas/enzimologia , Neoplasias Cutâneas/patologiaRESUMO
In this study, we have investigated the immunoexpression of peptide hormones and mediators associated with human islet cell tumors in a group of proliferative islet cell lesions in F344 rats including islet cell hyperplasias, adenomas, and carcinomas, as defined by conventional histopathologic criteria. All proliferative islets expressed synaptophysin, although decreased expression intensity was observed in hyperplasias and adenomas. Most of the proliferative lesions expressed insulin, which generally decreased as lesions progressed toward malignancy. The distribution of glucagon, somatostatin, and gastrin-expressing cells was altered in proliferative islet lesions but did not comprise a large proportion of cells. Islet cell tumors were associated with increased nuclear expression of cyclin-dependent kinase 4 as well as increased proliferating cell nuclear antigen and decreased ß-catenin expression. c-Myelocytomatosis oncogene expression was variable. This is the first study to describe the immunophenotype of islet cell tumors in the F344 rat and to show that islet cell tumors in the F344 rat exhibit similarities in protein expression to the human counterpart.
Assuntos
Adenoma de Células das Ilhotas Pancreáticas/patologia , Imuno-Histoquímica/métodos , Ilhotas Pancreáticas/patologia , Adenoma/patologia , Animais , Carcinoma/patologia , Proliferação de Células , Quinase 4 Dependente de Ciclina/genética , Quinase 4 Dependente de Ciclina/metabolismo , Feminino , Glucagon/metabolismo , Insulina/metabolismo , Ilhotas Pancreáticas/citologia , Masculino , Antígeno Nuclear de Célula em Proliferação/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Ratos , Ratos Endogâmicos F344 , Somatostatina/metabolismo , beta Catenina/genética , beta Catenina/metabolismoRESUMO
Aloe vera is one of the most commonly used botanicals for various prophylactic and therapeutic purposes. Recently, NTP/NCTR has demonstrated a dose-dependent increase in large intestinal tumors in F344 rats chronically exposed to Aloe barbadensis Miller (Aloe vera) non-decolorized whole leaf extract (AVNWLE) in drinking water. The morphological and molecular pathways of AVNWLE-induced large intestinal tumors in the F344 rats were compared to human colorectal cancer (hCRC) literature. Defined histological criteria were used to compare AVNWLE-induced large intestinal tumors with hCRC. The commonly mutated genes (Kras, Ctnnb1, and Tp53) and altered signaling pathways (MAPK, WNT, and TGF-ß) important in hCRC were evaluated within AVNWLE-induced large intestinal tumors. Histological evaluation of the large intestinal tumors indicated eight of twelve adenomas (Ads) and four of twelve carcinomas (Cas). Mutation analysis of eight Ads and four Cas identified point mutations in exons 1 and 2 of the Kras gene (two of eight Ads, two of four Cas), and in exon 2 of the Ctnnb1 gene (three of eight Ads, one of four Cas). No Tp53 (exons 5-8) mutations were found in Ads or Cas. Molecular pathways important in hCRC such as MAPK, WNT, and TGF-ß signaling were also altered in AVNWLE-induced Ads and Cas. In conclusion, the AVNWLE-induced large intestinal tumors in F344 rats share several similarities with hCRC at the morphological and molecular levels.
Assuntos
Aloe/química , Neoplasias Colorretais/metabolismo , Neoplasias Intestinais/induzido quimicamente , Neoplasias Intestinais/metabolismo , Extratos Vegetais/toxicidade , Adenoma/induzido quimicamente , Adenoma/metabolismo , Adenoma/patologia , Animais , Biomarcadores Tumorais/metabolismo , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Histocitoquímica , Humanos , Neoplasias Intestinais/patologia , Intestino Grosso/patologia , Folhas de Planta/química , Análise de Componente Principal , Ratos , Ratos Endogâmicos F344 , Transdução de Sinais/efeitos dos fármacosRESUMO
BACKGROUND: Bronchiolitis obliterans (BO) is a fibrotic lung disease that occurs in a variety of clinical settings, including toxin exposures, autoimmunity and lung or bone marrow transplant. Despite its increasing clinical importance, little is known regarding the underlying disease mechanisms due to a lack of adequate small animal BO models. Recent epidemiological studies have implicated exposure to diacetyl (DA), a volatile component of artificial butter flavoring, as a cause of BO in otherwise healthy factory workers. Our overall hypothesis is that DA induces severe epithelial injury and aberrant repair that leads to the development of BO. Therefore, the objectives of this study were 1) to determine if DA, delivered by intratracheal instillation (ITI), would lead to the development of BO in rats and 2) to characterize epithelial regeneration and matrix repair after ITI of DA. METHODS AND MAIN RESULTS: Male Sprague-Dawley rats were treated with a single dose of DA (125 mg/kg) or sterile water (vehicle control) by ITI. Instilled DA resulted in airway specific injury, followed by rapid epithelial regeneration, and extensive intraluminal airway fibrosis characteristic of BO. Increased airway resistance and lung fluid neutrophilia occurred with the development of BO, similar to human disease. Despite rapid epithelial regeneration after DA treatment, expression of the normal phenotypic markers, Clara cell secretory protein and acetylated tubulin, were diminished. In contrast, expression of the matrix component Tenascin C was significantly increased, particularly evident within the BO lesions. CONCLUSIONS: We have established that ITI of DA results in BO, creating a novel chemical-induced animal model that replicates histological, biological and physiological features of the human disease. Furthermore, we demonstrate that dysregulated epithelial repair and excessive matrix Tenacin C deposition occur in BO, providing new insights into potential disease mechanisms and therapeutic targets.
Assuntos
Bronquiolite Obliterante/complicações , Bronquiolite Obliterante/patologia , Mucosa Respiratória/patologia , Cicatrização , Animais , Bronquiolite Obliterante/induzido quimicamente , Bronquiolite Obliterante/fisiopatologia , Proliferação de Células , Diacetil , Progressão da Doença , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Matriz Extracelular/metabolismo , Regulação da Expressão Gênica , Instilação de Medicamentos , Masculino , Neutrófilos/patologia , Fibrose Pulmonar/complicações , Fibrose Pulmonar/patologia , Fibrose Pulmonar/fisiopatologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Regeneração , Testes de Função Respiratória , Mucosa Respiratória/fisiopatologia , Tenascina/genética , Tenascina/metabolismo , Uteroglobina/genética , Uteroglobina/metabolismoRESUMO
Cytochrome P-450 (CYP)-derived epoxyeicosatrienoic acids (EETs) possess potent anti-inflammatory effects in vitro. However, the effect of increased CYP-mediated EET biosynthesis and decreased soluble epoxide hydrolase (sEH, Ephx2)-mediated EET hydrolysis on vascular inflammation in vivo has not been rigorously investigated. Consequently, we characterized acute vascular inflammatory responses to endotoxin in transgenic mice with endothelial expression of the human CYP2J2 and CYP2C8 epoxygenases and mice with targeted disruption of Ephx2. Compared to wild-type controls, CYP2J2 transgenic, CYP2C8 transgenic, and Ephx2(-/-) mice each exhibited a significant attenuation of endotoxin-induced activation of nuclear factor (NF)-κB signaling, cellular adhesion molecule, chemokine and cytokine expression, and neutrophil infiltration in lung in vivo. Furthermore, attenuation of endotoxin-induced NF-κB activation and cellular adhesion molecule and chemokine expression was observed in primary pulmonary endothelial cells isolated from CYP2J2 and CYP2C8 transgenic mice. This attenuation was inhibited by a putative EET receptor antagonist and CYP epoxygenase inhibitor, directly implicating CYP epoxygenase-derived EETs with the observed anti-inflammatory phenotype. Collectively, these data demonstrate that potentiation of the CYP epoxygenase pathway by either increased endothelial EET biosynthesis or globally decreased EET hydrolysis attenuates NF-κB-dependent vascular inflammatory responses in vivo and may serve as a viable anti-inflammatory therapeutic strategy.
Assuntos
Hidrocarboneto de Aril Hidroxilases/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Epóxido Hidrolases/metabolismo , Inflamação/enzimologia , Doenças Vasculares/enzimologia , Animais , Hidrocarboneto de Aril Hidroxilases/genética , Células Cultivadas , Citocromo P-450 CYP2C8 , Citocromo P-450 CYP2J2 , Sistema Enzimático do Citocromo P-450/genética , Células Endoteliais/fisiologia , Endotoxemia/induzido quimicamente , Epóxido Hidrolases/genética , Feminino , Regulação Enzimológica da Expressão Gênica/fisiologia , Humanos , Lipopolissacarídeos/administração & dosagem , Lipopolissacarídeos/toxicidade , Masculino , Camundongos , Camundongos TransgênicosRESUMO
OBJECTIVE: To determine the associations of race, age and body mass index (BMI) with the gross pathology parameters of uterine leiomyomas in premenopausal women undergoing hysterectomy or myomectomy. STUDY DESIGN: Participants (N = 107) were recruited from surgical rosters of the George Washington University (GWU) Medical Center Gynecology Department as part of the National Institute of Environmental Health Sciences Fibroid Study. Tumor data and patient demographics were obtained from clinical reports, pathology forms and interviews. RESULTS: Surgical cases consisted of 78% African Americans, 13% Caucasians and 9% others (non-African American, non-Caucasian or race unknown). This proportion of African Americans was significantly higher than the distribution of GWU health plan participants. Fibroids were localized predominantly within the intramural region. Subserosal tumors were more common in patients with more than 9 tumors. African Americans had the highest mean BMI and mean myomatous uterine weight. CONCLUSION: African Americans were the disproportionate majority coming to surgery for fibroids. The average BMI and uterine weight were greater in African Americans than in Caucasians, although these differences were marginal. Race did not influence the size, location or number of fibroids in these surgical cases. Subserosal tumors were more common in patients with more than 9 tumors.
Assuntos
Leiomioma/etnologia , Neoplasias Uterinas/etnologia , Adulto , Negro ou Afro-Americano , Fatores Etários , Índice de Massa Corporal , Feminino , Humanos , Histerectomia , Leiomioma/patologia , Leiomioma/cirurgia , Leiomiomatose/etnologia , Leiomiomatose/patologia , Leiomiomatose/cirurgia , Pessoa de Meia-Idade , Pré-Menopausa , Neoplasias Uterinas/cirurgia , População BrancaRESUMO
The roles of sex hormones as modulators of lung function and disease have received significant attention as differential sex responses to various lung insults have been recently reported. The present study used a bleomycin-induced pulmonary fibrosis model in C57BL/6 mice to examine potential sex differences in physiological and pathological outcomes. Endpoints measured included invasive lung function assessment, immunological response, lung collagen deposition, and a quantitative histological analysis of pulmonary fibrosis. Male mice had significantly higher basal static lung compliance than female mice (P < 0.05) and a more pronounced decline in static compliance after bleomycin administration when expressed as overall change or percentage of baseline change (P < 0.05). In contrast, there were no significant differences between the sexes in immune cell infiltration into the lung or in total lung collagen content after bleomycin. Total lung histopathology scores measured using the Ashcroft method did not differ between the sexes, while a quantitative histopathology scoring system designed to determine where within the lung the fibrosis occurred indicated a tendency toward more fibrosis immediately adjacent to airways in bleomycin-treated male versus female mice. Furthermore, castrated male mice exhibited a female-like response to bleomycin while female mice given exogenous androgen exhibited a male-like response. These data indicate that androgens play an exacerbating role in decreased lung function after bleomycin administration, and traditional measures of fibrosis may miss critical differences in lung function between the sexes. Sex differences should be carefully considered when designing and interpreting experimental models of pulmonary fibrosis in mice.