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1.
Life Sci Alliance ; 4(2)2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33268505

RESUMO

Notch signaling exerts both oncogenic and tumor-suppressive functions in the pancreas. In this study, deletion of Jag1 in conjunction with oncogenic Kras G12D expression in the mouse pancreas induced rapid development of acinar-to-ductal metaplasia and early stage pancreatic intraepithelial neoplasm; however, culminating in cystic neoplasms rather than ductal adenocarcinoma. Most cystic lesions in these mice were reminiscent of serous cystic neoplasm, and the rest resembled intraductal papillary mucinous neoplasm. Jag1 expression was lost or decreased in cystic lesions but retained in adenocarcinoma in these mice, so was the expression of Sox9. In pancreatic cancer patients, JAG1 expression is higher in cancerous tissue, and high JAG1 is associated with poor overall survival. Expression of SOX9 is correlated with JAG1, and high SOX9 is also associated with poor survival. Mechanistically, Jag1 regulates expression of Lkb1, a tumor suppressor involved in the development of pancreatic cystic neoplasm. Collectively, Jag1 can act as a tumor suppressor in the pancreas by delaying precursor lesions, whereas loss of Jag1 promoted a phenotypic switch from malignant carcinoma to benign cystic lesions.

2.
Am J Pathol ; 190(11): 2194-2202, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32805234

RESUMO

The prostate epithelium consists of predominantly luminal cells that express androgen receptor and require androgens for growth. As a consequence, the depletion of testicular androgens in patients with prostate cancer results in tumor regression. However, it eventually leads to a castration-resistant disease that is highly metastatic. In this report, a mouse model of metastatic prostate cancer was generated through the deletion of the tumor-suppressor gene Trp53 in conjunction with oncogenic activation of the proto-oncogene Kras. These mice developed early-onset metastatic prostate cancer with complete penetrance. Tumors from these mice were poorly differentiated adenocarcinoma, characterized by extensive epithelial-mesenchymal transition. With no or a very low level of androgen receptor expression, the tumor cells were resistant to androgen receptor inhibition. Pik3cg, encoding phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit γ (Pi3kγ), was highly expressed in these tumors, and pharmacologic inhibition of Pi3kγ blocked tumor cell growth in vitro, reversed epithelial-mesenchymal transition, and abated tumor metastasis in vivo. Immunohistochemistry analysis in human prostate cancer specimens showed that the expression of PIK3CG was significantly associated with advanced clinical stages. Taken together, these results suggest that PIK3CG plays an important role in the progression and metastasis of prostate cancer, and may represent a new therapeutic target in the metastatic castration-resistant prostate cancer.


Assuntos
Classe Ib de Fosfatidilinositol 3-Quinase/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/metabolismo , Animais , Classe Ib de Fosfatidilinositol 3-Quinase/genética , Masculino , Camundongos , Camundongos Transgênicos , Metástase Neoplásica , Proteínas de Neoplasias/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Receptores Androgênicos/genética
3.
Neoplasia ; 21(8): 810-821, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31276933

RESUMO

Activating mutations and amplification of Kras and, more frequently, signatures for Kras activation are noted in stomach cancer. Expression of mutant KrasG12D in the mouse gastric mucosa has been shown to induce hyperplasia and metaplasia. However, the mechanisms by which Kras activation leads to gastric metaplasia are not fully understood. Here we report that KrasLSL-G12D/+;Pdx1-cre, a mouse model known for pancreatic cancer, also mediates KrasG12D expression in the stomach, causing gastric hyperplasia and metaplasia prior to the pathologic changes in the pancreas. These mice exhibit ectopic cell proliferation at the base of gastric glands, whereas wild-type mice contain proliferating cells primarily at the isthmus/neck of the gastric glands. Notch signaling is decreased in the KrasLSL-G12D/+;Pdx1-cre gastric mucosa, as shown by lower levels of cleaved Notch intracellular domains and downregulation of Notch downstream target genes. Expression of a Notch ligand Jagged1 is downregulated at the base of the mutant gland, accompanied by loss of chief cell marker Mist1. We demonstrate that exogenous Jagged1 or overexpression of Notch intracellular domain stimulates Mist1 expression in gastric cancer cell lines, suggesting positive regulation of Mist1 by Notch signaling. Finally, deletion of Jagged1 or Notch3 in KrasLSL-G12D/+;Pdx1-cre mice promoted development of squamous cell carcinoma in the forestomach, albeit short of invasive adenocarcinoma in the glandular stomach. Taken together, these results reveal downregulation of Notch signaling and Mist1 expression during the initiation of Kras-driven gastric tumorigenesis and suggest a tumor-suppressive role for Notch in this context.


Assuntos
Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Metaplasia/genética , Metaplasia/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Receptores Notch/metabolismo , Transdução de Sinais , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Modelos Animais de Doenças , Humanos , Hiperplasia , Imuno-Histoquímica , Proteína Jagged-1/metabolismo , Metaplasia/patologia , Camundongos , Camundongos Transgênicos , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Receptores Notch/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia
4.
Oncoscience ; 4(9-10): 131-138, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29142904

RESUMO

Background: Kras mutations and increased Notch activation occur frequently in gallbladder cancer. However, their roles in gallbladder carcinogenesis have not been defined. This study was aimed at determining whether expression of mutant Kras was sufficient to induce gallbladder carcinoma and whether Notch deregulation played a role in this context. Methods: We determined Cre recombination activity of Pdx1-Cre in the gallbladder using a reporter strain and examined gallbladder tumor development in the KrasLSL- G12D/+;Pdx1-Cre mice. We analyzed expression of Notch pathway genes in the mouse gallbladder by immunohistochemistry, quantitative RT-PCR, and Western blot analysis. We also determined the effect of Jag1 deletion on Kras-induced gallbladder tumor development. Results: Pdx1-Cre exhibits robust recombination activity in the gallbladder epithelium. KrasLSL-G12D/+;Pdx1-Cre mice form early onset adenoma in the gallbladder and adjacent biliary tract with complete penetrance, albeit short of invasive adenocarcinoma. KrasG12D upregulates expressions of Notch2, Notch3, Notch4, Jag1 and downstream target genes Hes1, Hey1 and Hey2, and deletion of Jag1 partially suppresses KrasG12D-induced adenoma development. Conclusions: KrasG12D induces gallbladder adenoma and Notch plays a key role in Kras-initiated gallbladder tumorigenesis.

5.
Neoplasia ; 19(11): 885-895, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28938159

RESUMO

Claudin-low breast cancer (CLBC) is a poor prognosis molecular subtype showing stemness and mesenchymal features. We previously discovered that deletion of a Notch signaling modulator, Lunatic Fringe (Lfng), in the mouse mammary gland induced a subset of tumors resembling CLBC. Here we report that deletion of one copy of p53 on this background not only accelerated mammary tumor development but also led to a complete penetrance of the mesenchymal stem-like phenotype. All mammary tumors examined in the Lfng/p53 compound mutant mice displayed a mesenchymal/spindloid pathology. These tumors showed high level expressions of epithelial-to-mesenchymal transition (EMT) markers including Vimentin, Twist, and PDGFRα, a gene known to be enriched in CLBC. Prior to tumor onset, Lfng/p53 mutant mammary glands exhibited increased levels of Vimentin and E-cadherin, but decreased expressions of cytokeratin 14 and cytokeratin 8, accompanied by elevated basal cell proliferation and an expanded mammary stem cell-enriched population. Lfng/p53 mutant glands displayed increased accumulation of Notch3 intracellular fragment, up-regulation of Hes5 and down-regulation of Hes1. Analysis in human breast cancer datasets found the lowest HES1 and second lowest LFNG expressions in CLBC among molecular subtypes, and low level of LFNG is associated with poor survival. Immunostaining of human breast cancer tissue array found correlation between survival and LFNG immunoreactivity. Finally, patients carrying TP53 mutations express lower LFNG than patients with wild type TP53. Taken together, these data revealed genetic interaction between Lfng and p53 in mammary tumorigenesis, established a new mouse model resembling CLBC, and may suggest targeting strategy for this disease.


Assuntos
Neoplasias da Mama/genética , Glicosiltransferases/genética , Células-Tronco Mesenquimais/fisiologia , Células-Tronco Neoplásicas/fisiologia , Proteína Supressora de Tumor p53/genética , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Claudinas/genética , Claudinas/metabolismo , Feminino , Glicosiltransferases/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Taxa de Sobrevida/tendências , Proteína Supressora de Tumor p53/metabolismo
6.
Cancer Res ; 75(10): 1936-43, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25808869

RESUMO

Claudin-low breast cancer (CLBC) is a poor prognosis disease biologically characterized by stemness and mesenchymal features. These tumors disproportionately affect younger patients and women with African ancestry, causing significant morbidity and mortality, and no effective targeted therapy exists at present. CLBC is thought to originate from mammary stem cells, but little is known on how or why these tumors express a stable epithelial-to-mesenchymal transition phenotype, or what are the driving forces of this disease. Here, we report that Manic Fringe (Mfng), which encodes an O-fucosylpeptide 3-ß-N-acetylglucosaminyltransferase known to modify EGF repeats in the Notch extracellular domain, is highly expressed in CLBC and functions as an oncogene in this context. We show that Mfng modulates Notch activation in human and mouse CLBC cell lines, as well as in mouse mammary gland. Mfng silencing in CLBC cell lines reduced cell migration, tumorsphere formation, and in vivo tumorigenicity associated with a decrease in the stem-like cell population. Mfng deletion in the Lfng(flox/flox);MMTV-Cre mouse model, in which one-third of mammary tumors resemble human CLBC, caused a tumor subtype shift away from CLBC. We identified the phosphoinositide kinase Pik3cg as a direct transcriptional target of Mfng-facilitated RBPJκ-dependent Notch signaling. Indeed, pharmacologic inhibition of PI3Kγ in CLBC cell lines blocked migration and tumorsphere formation. Taken together, our results define Mfng as an oncogene acting through Notch-mediated induction of Pik3cg. Furthermore, they suggest that targeting PI3Kγ may prove beneficial for the treatment of CLBC subtype.


Assuntos
Neoplasias da Mama/enzimologia , Classe Ib de Fosfatidilinositol 3-Quinase/genética , Claudinas/metabolismo , Hexosiltransferases/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Proteínas de Membrana/fisiologia , Receptores Notch/metabolismo , Animais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Classe Ib de Fosfatidilinositol 3-Quinase/metabolismo , Indução Enzimática , Transição Epitelial-Mesenquimal , Feminino , Glucosiltransferases , Humanos , Glândulas Mamárias Animais/metabolismo , Camundongos , Camundongos Knockout , Transplante de Neoplasias , Células-Tronco Neoplásicas/fisiologia , Fenótipo , Transdução de Sinais
7.
Sci Rep ; 5: 8782, 2015 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-25740432

RESUMO

Members of the Notch family of transmembrane receptors, Notch1-4 in mammals, are involved in the regulation of cell fate decisions and cell proliferation in various organisms. The Notch4 isoform, which is specific to mammals, was originally identified as a viral oncogene in mice, Int3, able to initiate mammary tumors. In humans, Notch4 expression appears to be associated with breast cancer stem cells and endocrine resistance. Following ligand binding, the Notch4 receptor undergoes cleavage at the membrane and the Notch4-intracellular domain (ICD), translocates to the nucleus and regulates gene transcription. Little is known on the mechanisms regulating Notch4-ICD and its nuclear localization. Here, we describe the identification of four distinct AKT phosphorylation sites in human Notch4-ICD and demonstrate that AKT binds Notch4-ICD and phosphorylates all four sites in vitro and in vivo. The phosphorylation in cells is regulated by growth factors and is sensitive to phosphatidyl inositol-3 kinase (PI3K) inhibitors. This phosphorylation generates binding sites to the 14-3-3 regulatory proteins, which are involved in the regulation of nucleocytoplasmic shuttling of target proteins, restricting phosphorylated Notch4-ICD to the cytoplasm. Our findings provide a novel mechanism for Notch4-ICD regulation, suggesting a negative regulatory role for the PI3K-AKT pathway in Notch4 nuclear signaling.


Assuntos
Proteínas 14-3-3/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores Notch/metabolismo , Transporte Ativo do Núcleo Celular , Animais , Sítios de Ligação , Linhagem Celular , Citoplasma , Humanos , Fosforilação , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas Proto-Oncogênicas/química , Receptor Notch4 , Receptores Notch/química
8.
Neoplasia ; 16(2): 158-67, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24709423

RESUMO

Elevated Notch ligand and receptor expression has been associated with aggressive forms of prostate cancer, suggesting a role for Notch signaling in regulation of prostate tumor initiation and progression. Here, we report a critical role for Lunatic Fringe (Lfng), which encodes an O-fucosylpeptide 3-ß-N-acetylglucosaminyltransferase known to modify epidermal growth factor repeats of Notch receptor proteins, in regulation of prostate epithelial differentiation and proliferation, as well as in prostate tumor suppression. Deletion of Lfng in mice caused altered Notch activation in the prostate, associated with elevated accumulation of Notch1, Notch2, and Notch4 intracellular domains, decreased levels of the putative Notch3 intracellular fragment, as well as increased expression of Hes1, Hes5, and Hey2. Loss of Lfng resulted in expansion of the basal layer, increased proliferation of both luminal and basal cells, and ultimately, prostatic intraepithelial neoplasia. The Lfng-null prostate showed down-regulation of prostatic tumor suppressor gene NKX3.1 and increased androgen receptor expression. Interestingly, expression of LFNG and NKX3.1 were positively correlated in publically available human prostate cancer data sets. Knockdown of LFNG in DU-145 prostate cancer cells led to expansion of CD44(+)CD24(-) and CD49f(+)CD24(-) stem/progenitor-like cell population associated with enhanced prostatosphere-forming capacity. Taken together, these data revealed a tumor-suppressive role for Lfng in the prostate through differential regulation of Notch signaling.


Assuntos
Genes Supressores de Tumor , Glicosiltransferases/fisiologia , Próstata/metabolismo , Neoplasias da Próstata/genética , Receptores Notch/metabolismo , Animais , Proliferação de Células , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Proteínas de Homeodomínio/metabolismo , Humanos , Masculino , Camundongos Knockout , Próstata/patologia , Neoplasias da Próstata/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptor Notch1/metabolismo , Receptor Notch2/metabolismo , Receptor Notch3 , Receptor Notch4 , Receptores Androgênicos/metabolismo , Fatores de Transcrição/metabolismo
9.
Cancer Biol Ther ; 15(5): 633-42, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24556651

RESUMO

Triple negative breast cancer (TNBC) accounts for 15-20% of breast carcinomas and represents one of the most aggressive forms of this disease. Basal and claudin-low are the two main molecular subtypes among TNBCs. We previously reported that deletion of Lfng in mouse mammary gland caused deregulated Notch activation and induced basal-like and claudin-low tumors with co-selection for Met amplification. In human breast cancers, the vast majority of basal tumors and a subset of claudin-low tumors show reduced Lfng expression. Elevated Met expression and activation is associated with basal as well as claudin-low subtypes. To examine roles of Met and Notch in TNBC cells, we established two cell lines that harbor Met amplification as well as Lfng deletion, and possess features of basal and claudin-low breast cancer subtypes. Pharmacological inhibition of Met not only suppressed cell growth, tumorsphere and colony formation, but also reversed epithelial-to-mesenchymal transition and inhibited cell migration in both cell lines. In contrast, inhibition of Notch signaling using a γ-secretase inhibitor (GSI) only suppressed colony formation. Interestingly, GSI had no effect as single agent, but exerted a synergistic effect with Met inhibitor, on cell growth in 2D culture. We found that inhibition of Met resulted in downregulation of Dll ligands and upregulation of Jagged ligands, leading to differential modulation of Notch signaling. Our results suggest that combination targeting of Met and Notch may prove beneficial for TNBC patients with Met overexpression and Notch hyperactivation.


Assuntos
Glicosiltransferases/genética , Proteínas Proto-Oncogênicas c-met/metabolismo , Receptores Notch/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Derivados de Benzeno/farmacologia , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Expressão Gênica , Indóis/farmacologia , Camundongos , Camundongos Knockout , Terapia de Alvo Molecular , Piperazinas/farmacologia , Propionatos/farmacologia , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-met/genética , Transdução de Sinais , Sulfonamidas/farmacologia , Sulfonas/farmacologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Células Tumorais Cultivadas/efeitos dos fármacos
10.
J Biol Chem ; 289(9): 6054-66, 2014 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-24446434

RESUMO

AKT/PKB kinases transmit insulin and growth factor signals downstream of phosphatidylinositol 3-kinase (PI3K). AKT activation involves phosphorylation at two residues, Thr(308) and Ser(473), mediated by PDK1 and the mammalian target of rapamycin complex 2 (mTORC2), respectively. Impaired AKT activation is a key factor in metabolic disorders involving insulin resistance, whereas hyperactivation of AKT is linked to cancer pathogenesis. Here, we identify the cytoplasmic NAD(+)-dependent deacetylase, Sirt2, as a novel AKT interactor, required for optimal AKT activation. Pharmacological inhibition or genetic down-regulation of Sirt2 diminished AKT activation in insulin and growth factor-responsive cells, whereas Sirt2 overexpression enhanced the activation of AKT and its downstream targets. AKT was prebound with Sirt2 in serum or glucose-deprived cells, and the complex dissociated following insulin treatment. The binding was mediated by the pleckstrin homology and the kinase domains of AKT and was dependent on AMP-activated kinase. This regulation involved a novel AMP-activated kinase-dependent Sirt2 phosphorylation at Thr(101). In cells with constitutive PI3K activation, we found that AKT also associated with a nuclear sirtuin, Sirt1; however, inhibition of PI3K resulted in dissociation from Sirt1 and increased association with Sirt2. Sirt1 and Sirt2 inhibitors additively inhibited the constitutive AKT activity in these cells. Our results suggest potential usefulness of Sirt1 and Sirt2 inhibitors in the treatment of cancer cells with up-regulated PI3K activity and of Sirt2 activators in the treatment of insulin-resistant metabolic disorders.


Assuntos
Insulina/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Sirtuína 2/metabolismo , Células 3T3-L1 , Animais , Células COS , Chlorocebus aethiops , Ativação Enzimática/fisiologia , Células HeLa , Humanos , Insulina/genética , Camundongos , Células NIH 3T3 , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/fisiologia , Ligação Proteica , Proteínas Proto-Oncogênicas c-akt/genética , Sirtuína 1/antagonistas & inibidores , Sirtuína 1/genética , Sirtuína 1/metabolismo , Sirtuína 2/genética
11.
Korean J Parasitol ; 51(1): 31-6, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23467308

RESUMO

An overview of the epidemiological, biological, and clinical studies of Taenia and taeniasis in Taiwan for the past century is presented. The phenomenal observations that led to the discovery of Taenia asiatica as a new species, which differ from Taenia solium and Taenia saginata, are described. Parasitological surveys of the aborigines in Taiwan revealed a high prevalence of taeniasis, which might be due to the culture of eating raw liver of hunted wild boars. Chemotherapeutic deworming trials involving many patients with taeniasis were discussed. Praziquantel was found to be very effective, but sometimes complete worms could not be recovered from the feces after treatment, probably due to the dissolution of the proglottids. Atabrine, despite some side effects, can still be used, in properly controlled dosages, as the drug of choice for human T. asiatica infection if we need to recover the expelled worms for morphological examinations. Research results on the infection of T. asiatica eggs from Taiwan aborigines in experimental animals were also noted. Since the pig serve as the natural intermediate host of T. asiatica and the predilection site is the liver, a differential comparison of other parasitic pathogens that might cause apparently similar lesions is also presented.


Assuntos
Taenia/classificação , Taenia/isolamento & purificação , Teníase/epidemiologia , Animais , Anti-Helmínticos/uso terapêutico , Pesquisa Biomédica/história , História do Século XX , História do Século XXI , Humanos , Teníase/tratamento farmacológico , Teníase/história , Taiwan/epidemiologia
12.
J Insect Sci ; 11: 76, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21867442

RESUMO

Infection rate, reaction to light, and hair follicle apoptosis are examined in the dogmite, Demodex canis Leydig (Prostigmata: Demodicidae), in dogs from the northern area of Taiwan. An analysis of relevant samples revealed 7.2% (73/1013) prevalence of D. canis infection. Infection during the investigation peaked each winter, with an average prevalence of 12.5% (32/255). The infection rates significantly varied in accordance with month, sex, age, and breed (p < 0.05). Most of the lesions were discovered on the backs of the infected animals, where the infection rate was 52.1% (38/73) (P < 0.05). The epidemiologic analysis of infection based on landscape area factor, found that employing a map-overlapping method showed a higher infection rate in the eastern distribution of Taiwan's northern area than other areas. Isolation tests for Microsporum canis Bodin (Onygenales: Arthrodermataceae) and Trichophyton mentagrophyte Robin (Blanchard) on the D. canis infected dogs revealed prevalence rates of 4.4% (2/45) and 2.2% (1/45), respectively. Observations demonstrated that D. canis slowly moved from a light area to a dark area. Skin samples were examined for cellular apoptosis by activated caspase3 immunohistochemical staining. Cells that surrounded the infected hair follicles were activated caspase3-positive, revealing cell apoptosis in infected follicles via the activation of caspase3.


Assuntos
Dermatomicoses/microbiologia , Doenças do Cão/epidemiologia , Interações Hospedeiro-Parasita , Infestações por Ácaros/veterinária , Ácaros/fisiologia , Animais , Apoptose , Comorbidade , Dermatomicoses/epidemiologia , Doenças do Cão/microbiologia , Doenças do Cão/parasitologia , Cães , Eosinófilos , Feminino , Folículo Piloso/patologia , Contagem de Leucócitos , Luz , Masculino , Microsporum/isolamento & purificação , Infestações por Ácaros/epidemiologia , Infestações por Ácaros/microbiologia , Infestações por Ácaros/patologia , Prevalência , Taiwan/epidemiologia , Trichophyton/isolamento & purificação
13.
Cancer Prev Res (Phila) ; 4(8): 1306-15, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21505178

RESUMO

Lung cancer is the leading cause of cancer-related mortality worldwide. Early detection or prevention strategies are urgently needed to increase survival. Hyperplasia is the first morphologic change that occurs in the bronchial epithelium during lung cancer development, followed by squamous metaplasia, dysplasia, carcinoma in situ, and invasive tumor. This study was designed to determine the molecular mechanisms that control bronchial epithelium hyperplasia. Using primary normal human tracheobronchial epithelial (NHTBE) cells cultured by using the 3-dimensional (3D) organotypic method, we found that the epidermal growth factor receptor (EGFR) ligands, EGF, TGF-α, and amphiregulin induced hyperplasia, as determined by cell proliferation and multilayered epithelium formation. We also found that EGF induced increased cyclin D1 expression, which plays a critical role in bronchial hyperplasia; this overexpression was mediated by activating the mitogen-activated protein kinase pathway but not the phosphoinositide 3-kinase/Akt signaling pathway. Erlotinib, an EGFR tyrosine kinase inhibitor, and U0126, a MAP/ERK kinase (MEK) inhibitor, completely inhibited EGF-induced hyperplasia. Furthermore, a promoter analysis revealed that the activator protein-1 transcription factor regulates EGF-induced cyclin D1 overexpression. Activator protein-1 depletion by using siRNA targeting its c-Jun component completely abrogated EGF-induced cyclin D1 expression. In conclusion, we showed that bronchial hyperplasia can be modeled in vitro by using primary NHTBE cells maintained in a 3D organotypic culture. EGFR and MEK inhibitors completely blocked EGF-induced bronchial hyperplasia, suggesting that they have a chemopreventive role.


Assuntos
Brônquios/efeitos dos fármacos , Brônquios/patologia , Receptores ErbB/antagonistas & inibidores , Hiperplasia/patologia , Butadienos/farmacologia , Linhagem Celular Tumoral , Ciclina D1/metabolismo , Inibidores Enzimáticos/farmacologia , Cloridrato de Erlotinib , Humanos , Luciferases/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , MAP Quinase Quinase Quinases/antagonistas & inibidores , Modelos Biológicos , Nitrilos/farmacologia , Técnicas de Cultura de Órgãos/métodos , Quinazolinas/farmacologia , RNA Interferente Pequeno/metabolismo
14.
J Immunol ; 182(4): 2349-56, 2009 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-19201889

RESUMO

Mucus secretion is an important protective mechanism for the luminal lining of open tubular organs, but mucin overproduction in the respiratory tract can exacerbate the inflammatory process and cause airway obstruction. Production of MUC5AC, a predominant gel-forming mucin secreted by airway epithelia, can be induced by various inflammatory mediators such as prostaglandins. The two major prostaglandins involved in inflammation are PGE(2) and PGF(2alpha). PGE(2)-induced mucin production has been well studied, but the effect of PGF(2alpha) on mucin production remains poorly understood. To elucidate the effect and underlying mechanism of PGF(2alpha) on MUC5AC production, we investigated the signal transduction of PGF(2alpha) associated with this effect using normal human tracheobronchial epithelial cells. Our results demonstrated that PGF(2alpha) induces MUC5AC overproduction via a signaling cascade involving protein kinase C, ERK, p90 ribosomal S6 protein kinase, and CREB. The regulation of PGF(2alpha)-induced MUC5AC expression by CREB was further confirmed by cAMP response element-dependent MUC5AC promoter activity and by interaction between CREB and MUC5AC promoter. The abrogation of all downstream signaling activities via suppression of each signaling molecule along the pathway indicates that a single pathway from PGF(2alpha) receptor to CREB is responsible for inducing MUC5AC overproduction. As CREB also mediates mucin overproduction induced by PGE(2) and other inflammatory mediators, our findings have important clinical implications for the management of airway mucus hypersecretion.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Dinoprosta/metabolismo , Células Epiteliais/metabolismo , Mucina-5AC/biossíntese , Mucosa Respiratória/metabolismo , Transdução de Sinais/fisiologia , Western Blotting , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/imunologia , Dinoprosta/imunologia , Células Epiteliais/imunologia , Citometria de Fluxo , Imunofluorescência , Humanos , Mucina-5AC/imunologia , Análise de Sequência com Séries de Oligonucleotídeos , Interferência de RNA , Mucosa Respiratória/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção
15.
Res Vet Sci ; 86(2): 261-6, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18752819

RESUMO

Normal C3H/HeN female mice were used to develop an animal model of Taenia saginata asiatica oncosphere infection. The host cellular immune response in this model was analyzed by a cytokine enzyme-linked immunosorbent assay (cytokine ELISA) and flow cytometry. Tumor-like cysts containing cysticerci were recovered from the inoculation sites of female mice 7 weeks postinfection with the T. saginata asiatica oncospheres. A sharp increase and sustained elevation in the ability of spleen cells to produce interferon-gamma and interleukin (IL)-2 revealed that cellular immunity played an important role during the infection. An immediate increase in the levels of IL-6 at 1 week postinfection indicated the induction of a local acute inflammatory response. However, no significant change in the levels of IL-10 indicated that Th2 cells were not involved in this immune response. The patterns of cell distribution revealed by flow cytometry also supported the same finding. These results suggested that Th1 cells played a major role in the immune response in C3H/HeN mice during the early stages of the oncosphere infection and that the Th2 response was not induced during the stage of cysticercus formation.


Assuntos
Taenia saginata/imunologia , Teníase/imunologia , Animais , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Humanos , Imunidade Celular/imunologia , Interferon gama/imunologia , Interleucinas/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Projetos Piloto , Baço/imunologia , Baço/parasitologia , Linfócitos T/imunologia , Teníase/parasitologia
16.
Cancer Res ; 68(4): 981-8, 2008 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-18281471

RESUMO

Genes regulated by cyclic AMP-response element-binding protein (CREB) have been reported to suppress apoptosis, induce cell proliferation, and mediate inflammation and tumor metastasis. However, it is not clear whether CREB is critically involved in lung carcinogenesis. We found that non-small cell lung cancer (NSCLC) cell lines exhibited elevated constitutive activity in CREB, in its immediate upstream kinases (ribosomal s6 kinase and extracellular signal kinase), and in the CREB-regulated cell survival proteins Bcl-2 and Bcl-xL. We hypothesized that constitutively active CREB is important to lung cancer cell growth and survival and therefore could be a potential therapeutic target for NSCLC. Ectopic expression of dominant repressor CREB and transfection with small interfering RNA against CREB suppressed the growth and survival of NSCLC cells and induced apoptotic cell death. Furthermore, treating H1734 NSCLC cells with an inhibitor of the CREB signaling pathway Ro-31-8220 inhibited CREB activation by blocking the activity of extracellular signal kinase and ribosomal s6 kinase, arrested the cell cycle at the G(2)-M phase, and subsequently induced apoptosis with the suppression of Bcl-2 and Bcl-xL expression. Ro-31-8220 suppressed both the anchorage-dependent and independent growth of NSCLC cells, but its cytotoxic effect was much less prominent in normal bronchial epithelial cells. Our results indicate that active CREB plays an important role in NSCLC cell growth and survival. Thus, agents that suppress CREB activation could have potential therapeutic value for NSCLC treatment.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/antagonistas & inibidores , Indóis/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Apoptose/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Divisão Celular/efeitos dos fármacos , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Fase G2/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
17.
J Parasitol ; 94(6): 1437, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19127965

RESUMO

From October 2005 through September 2006, blood samples collected from 1,412 (768 male, 644 female) 1-yr-old and older stray dogs in Taipei City, Taiwan, were tested for antibodies to Toxoplasma gondii using the latex agglutination test (LAT). Antibodies (LAT titers >1:32) to T. gondii were found in 284 (20.1%) of the animals. Seroprevalences were not affected by the sex or density of dogs. The prevalence was highest in dogs from the eastern part of the city.


Assuntos
Anticorpos Antiprotozoários/sangue , Doenças do Cão/epidemiologia , Toxoplasma/imunologia , Toxoplasmose Animal/epidemiologia , Animais , Doenças do Cão/parasitologia , Cães , Feminino , Umidade , Testes de Fixação do Látex/veterinária , Masculino , Chuva , Estações do Ano , Estudos Soroepidemiológicos , Taiwan/epidemiologia , Saúde da População Urbana
18.
Cancer Prev Res (Phila) ; 1(5): 316-28, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19138976

RESUMO

The recognition of the importance of angiogenesis in tumor progression has led to the development of antiangiogenesis as a new strategy for cancer treatment and prevention. By modulating tumor microenvironment and inducing angiogenesis, the proinflammatory cytokine interleukine (IL)-1beta has been reported to promote tumor development. However, the factors mediating IL-1beta-induced angiogenesis in non-small cell lung cancer (NSCLC) and the regulation of these angiogenic factors by IL-1beta are less clear. Here, we report that IL-1beta up-regulated an array of proangiogenic CXC chemokine genes in the NSCLC cell line A549 and in normal human tracheobronchial epithelium cells, as determined by microarray analysis. Further analysis revealed that IL-1beta induced much higher protein levels of CXC chemokines in NSCLC cells than in normal human tracheobronchial epithelium cells. Conditioned medium from IL-1beta-treated A549 cells markedly increased endothelial cell migration, which was suppressed by neutralizing antibodies against CXCL5 and CXCR2. We also found that IL-1beta-induced CXC chemokine gene overexpression in NSCLC cells was abrogated with the knockdown of cyclic AMP-responsive element binding protein (CREB) or nuclear factor kappaB (NF-kappaB). Moreover, the expression of the CXC chemokine genes as well as CREB and NF-kappaB activities was greatly increased in the tumorigenic NSCLC cell line compared with normal, premalignant immortalized or nontumorigenic cell lines. A disruptor of the interaction between CREB-binding protein and transcription factors such as CREB and NF-kappaB, 2-naphthol-AS-E-phosphate (KG-501), inhibited IL-1beta-induced CXC chemokine gene expression and angiogenic activity in NSCLC. We propose that targeting CREB or NF-kappaB using small-molecule inhibitors, such as KG-501, holds promise as a preventive and/or therapeutic approach for NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Quimiocinas CXC/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/fisiologia , Neoplasias Pulmonares/genética , NF-kappa B/fisiologia , Carcinoma Pulmonar de Células não Pequenas/irrigação sanguínea , Carcinoma Pulmonar de Células não Pequenas/patologia , Células Cultivadas , Quimiocina CXCL5/metabolismo , Quimiocinas CXC/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/antagonistas & inibidores , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-1beta/farmacologia , Interleucina-8/metabolismo , Neoplasias Pulmonares/irrigação sanguínea , Neoplasias Pulmonares/patologia , NF-kappa B/antagonistas & inibidores , NF-kappa B/genética , NF-kappa B/metabolismo , Naftóis/farmacologia , Neovascularização Patológica/genética , Análise de Sequência com Séries de Oligonucleotídeos , Organofosfatos/farmacologia , RNA Interferente Pequeno/farmacologia
19.
Mol Cell Biol ; 27(19): 6933-47, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17646388

RESUMO

Vitamin A and its metabolite retinoic acid (RA) are essential elements for normal lung development and the differentiation of lung epithelial cells. We previously showed that RA rapidly activated cyclic AMP response element-binding protein (CREB) in a nonclassical manner in normal human tracheobronchial epithelial (NHTBE) cells. In the present study, we further demonstrated that this nonclassical signaling of RA on the activation of CREB plays a critical role in regulating the expression of airway epithelial cell differentiation markers, the MUC2, MUC5AC, and MUC5B genes. We found that RA rapidly activates the protein kinase Calpha isozyme and transmits the activation signal to CREB via the Raf/MEK/extracellular signal-regulated kinase/p90 ribosomal S6 kinase (RSK) pathway. Activated RSK translocated from the cytoplasm to the nucleus, where it phosphorylates CREB. Activated CREB then binds to a cis-acting replication element motif on the promoter (at nucleotides [nt] -878 to -871) of the MUC5AC gene. The depletion of CREB using small interfering RNA abolished not only the RA-induced MUC5AC but also RA-induced MUC2 and MUC5B. Taken together, our findings demonstrate that CREB activation via this nonclassical RA signaling pathway may play an important role in regulating the expression of mucin genes and mediating the early biological effects of RA during normal mucous differentiation in NHTBE cells.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Regulação da Expressão Gênica , Mucinas , Transdução de Sinais/fisiologia , Tretinoína/metabolismo , Células Cultivadas , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Ativação Enzimática , Células Epiteliais/citologia , Células Epiteliais/fisiologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Isoenzimas/metabolismo , MAP Quinase Quinase Quinases/metabolismo , Mucina-5AC , Mucina-2 , Mucina-5B , Mucinas/genética , Mucinas/metabolismo , Proteína Quinase C-alfa/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Receptores do Ácido Retinoico/metabolismo , Mucosa Respiratória/citologia , Receptores X Retinoide/metabolismo , Proteínas Quinases S6 Ribossômicas/metabolismo , Quinases raf/metabolismo
20.
J Parasitol ; 93(6): 1540-1, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18314712

RESUMO

From May 2003 to April 2004, blood samples from 395 feeder pigs in Taiwan were examined for antibodies to Toxoplasma gondii using the latex agglutination test; antibodies (titer 1:32 or higher) were found in 10.1% of 395 pigs. The results indicate a high prevalence of infection in pigs in Taiwan destined for human consumption.


Assuntos
Anticorpos Antiprotozoários/sangue , Doenças dos Suínos/epidemiologia , Toxoplasma/imunologia , Toxoplasmose Animal/epidemiologia , Matadouros , Animais , Testes de Fixação do Látex/veterinária , Estações do Ano , Estudos Soroepidemiológicos , Suínos , Taiwan/epidemiologia
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