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1.
Case Rep Oncol Med ; 2018: 6314392, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29808141

RESUMO

Pancreatic cancer is the fourth most common cancer death in the United States despite comprising a small percentage of the total number of cancer cases. The estimated 5-year overall survival (OS) for patients with distant metastatic disease is approximately 3%. New treatment options are an unmet need and remain an area of active investigation. A 53-year-old male with metastatic pancreatic cancer presented to the hospital with acute-on-chronic respiratory failure approximately 24 hours after receiving a novel therapeutic combination. Chest imaging showed marked changes as concerning for pneumonitis. Infectious workup was negative. The patient had initial clinical improvement after receiving initial intravenous steroids and oxygen support but eventually deteriorated later opting for supportive measures only. With infection ruled out, drug-induced pneumonitis was felt to be the likely cause of the radiologic and clinical changes. The rapidity of onset of symptoms is the aspect being highlighted in this case.

2.
Cancer ; 123(13): 2413-2421, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28195643

RESUMO

BACKGROUND: Postdiagnosis weight gain in patients with breast cancer has been associated with increased cancer recurrence and mortality. This study was designed to identify risk factors for weight gain and create a predictive model to identify a high-risk population for targeted interventions. METHODS: The weight of 393 patients with breast cancer from the Northwestern Robert H. Lurie Cancer Center was measured over a 2-year period from diagnosis, with body mass index (BMI) change over 18 months as the primary endpoint. Demographics, clinical factors, treatment methods, as well as tumor characteristics were also recorded; and a lifestyle questionnaire was conducted. Blood samples were genotyped for 16 single nucleotide polymorphisms in FTO, adiponectin pathway genes (ADIPOQ, ADIPOR1), and FNDC5. Serum leptin, adiponectin, and irisin levels also were measured. RESULTS: Mean ± standard deviation 18-month BMI changes were 0.68 ± 1.42, 0.98 ± 1.62, 0.79 ± 1.74, and -0.44 ± 1.58 kg/m2 for patients ages <40, 40 to 49, 50 to 59, and ≥60 years, respectively. The optimal multivariable model for 18-month BMI change contained the predictors age, height, and endocrine therapy, but only age was statistically significant, with a 0.04 kg/m2 increase in 18-month BMI change per younger year of age. Single nucleotide polymorphisms in ADIPOR1, FTO, and FNDC5 were associated with 18-month BMI change, and the first 2 remained significant after adjusting for the optimal clinical model (all P < .05). CONCLUSIONS: Women age 60 years and younger at the time of breast cancer diagnosis who have an obesity genetic risk model are at increased risk for weight gain after treatment and should be targeted for weight-maintenance interventions. Cancer 2017;123:2413-21. © 2017 American Cancer Society.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/terapia , Obesidade/genética , Radioterapia , Sobreviventes , Aumento de Peso/genética , Adiponectina/sangue , Adiponectina/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Antraciclinas/uso terapêutico , Antineoplásicos/uso terapêutico , Índice de Massa Corporal , Neoplasias da Mama/patologia , Feminino , Fibronectinas/sangue , Fibronectinas/genética , Genótipo , Humanos , Leptina/sangue , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Receptores de Adiponectina/genética , Fatores de Risco
3.
BMC Med Genet ; 12: 52, 2011 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-21489227

RESUMO

BACKGROUND: Obesity has been shown to increase breast cancer risk. FTO is a novel gene which has been identified through genome wide association studies (GWAS) to be related to obesity. Our objective was to evaluate tissue expression of FTO in breast and the role of FTO SNPs in predicting breast cancer risk. METHODS: We performed a case-control study of 354 breast cancer cases and 364 controls. This study was conducted at Northwestern University. We examined the role of single nucleotide polymorphisms (SNPs) of intron 1 of FTO in breast cancer risk. We genotyped cases and controls for four SNPs: rs7206790, rs8047395, rs9939609 and rs1477196. We also evaluated tissue expression of FTO in normal and malignant breast tissue. RESULTS: We found that all SNPs were significantly associated with breast cancer risk with rs1477196 showing the strongest association. We showed that FTO is expressed both in normal and malignant breast tissue. We found that FTO genotypes provided powerful classifiers to predict breast cancer risk and a model with epistatic interactions further improved the prediction accuracy with a receiver operating characteristic (ROC) curves of 0.68. CONCLUSION: In conclusion we have shown a significant expression of FTO in malignant and normal breast tissue and that FTO SNPs in intron 1 are significantly associated with breast cancer risk. Furthermore, these FTO SNPs are powerful classifiers in predicting breast cancer risk.


Assuntos
Neoplasias da Mama/genética , Proteínas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Dioxigenase FTO Dependente de alfa-Cetoglutarato , Neoplasias da Mama/patologia , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Íntrons , Pessoa de Meia-Idade , Razão de Chances , Polimorfismo de Nucleotídeo Único , Proteínas/fisiologia , Risco
4.
Metabolism ; 60(9): 1234-43, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21397927

RESUMO

Studies have linked prostate cancer risk with insulin resistance and obesity. Circulating levels of adiponectin, a protein involved in insulin resistance and obesity, have been associated with prostate cancer risk. We studied the association of prostate cancer risk with haplotype tagging single nucleotide polymorphisms (SNPs) of the adiponectin (ADIPOQ) and adiponectin receptor 1 (ADIPOR1) chosen based on their functional relevance or association with other types of cancer. DNA samples from 465 cases and 441 healthy volunteers from New York City were genotyped for ADIPOQ rs266729, rs822395, rs822396, rs1501299, and rs2241766 SNPs and ADIPOR1 rs12733285, rs1342387, rs7539542, rs2232853, and rs10920531 SNPs. We performed both single- and multiple-SNP analyses. We found that rs12733285, rs7539452, rs266729, rs822395, rs822396, and rs1501299 were significantly associated with prostate cancer risk. Haplotype analysis confirmed these results and identified 5 ADIPOQ 4-SNP haplotypes and 1 ADIPOR1 2-SNP haplotype tightly associated with prostate cancer risk. Importantly, 2 ADIPOQ SNPs, rs266729 and rs1501299, have been previously associated with colon and breast cancer risk, respectively, in the same direction as in this study. These findings suggest that variants of the adiponectin pathway may be associated with susceptibility to various forms of common cancers and warrant validation studies.


Assuntos
Polimorfismo de Nucleotídeo Único , Neoplasias da Próstata/genética , Receptores de Adiponectina/genética , Adiponectina/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Epistasia Genética , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/etiologia , Risco
5.
J Exp Clin Cancer Res ; 29: 57, 2010 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-20500843

RESUMO

PURPOSE: Constitutively decreased TGFBR1 allelic expression is emerging as a potent modifier of colorectal cancer risk in mice and humans. This phenotype was first observed in mice, then in lymphoblastoid cell lines from patients with microsatellite stable colorectal tumors. PATIENTS AND METHODS: We assessed the frequency of constitutively decreased TGFBR1 allelic expression and association with SNPs covering the TGFBR1 locus using RNA and DNA extracted from the peripheral blood lymphocytes of 118 consecutive patients with biopsy-proven adenocarcinoma of the colon or the rectum. RESULTS: We found that 11(9.3%) of 118 patients exhibited decreased TGFBR1 allelic expression (TGFBR1 ASE). TGFBR1 ASE was strongly associated with three SNPs in linkage disequilibrium with each other: rs7034462 (p = 7.2 x 10-4), TGFBR1*6A (p = 1.6 x 10-4) and rs11568785 (p = 1.4 x 10-4). CONCLUSION: These results confirm the high prevalence of constitutively decreased TGFBR1 allelic expression among patients with colorectal cancer. The association of this phenotype with TGFBR1*6A, rs7034462 and rs1156875 suggests an association between TGFBR1 SNPs and colorectal cancer, which warrants additional studies.


Assuntos
Adenocarcinoma/genética , Neoplasias Colorretais/genética , Polimorfismo de Nucleotídeo Único/genética , Proteínas Serina-Treonina Quinases/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Western Blotting , Neoplasias Colorretais/patologia , Estudos Transversais , DNA de Neoplasias/genética , Feminino , Haplótipos/genética , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prognóstico , RNA Mensageiro/genética , RNA Neoplásico/genética , Receptor do Fator de Crescimento Transformador beta Tipo I
6.
Cancer Res ; 69(24): 9169-74, 2009 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-19951995

RESUMO

To dissect the role of constitutively altered Tgfbr1 signaling in pancreatic cancer development, we crossed Elastase-Kras(G12D) (EL-Kras) mice with Tgfbr1 haploinsufficient mice to generate EL-Kras/Tgfbr1(+/-) mice. Mice were euthanized at 6 to 9 months to compare the incidence, frequency, and size of precancerous lesions in the pancreas. Only 50% of all EL-Kras/Tgfbr1(+/-) mice developed preinvasive lesions compared with 100% of EL-Kras (wild-type Tgfbr1) mice. The frequency of precancerous lesions was 4-fold lower in haploinsufficient than in control mice. Paradoxically, the precancerous lesions of EL-Kras/Tgfbr1(+/-) mice were considerably larger than those in EL-Kras mice. Yet, the mitotic index of precancerous cells and the observable levels of fibrosis, lipoatrophy, and lymphocytic infiltration were reduced in EL-Kras/Tgfbr1(+/-) mice. We conclude that Tgfbr1 signaling promotes the development of precancerous lesions in mice. These findings suggest that individuals with constitutively decreased TGFBR1 expression may have a decreased risk of pancreatic cancer.


Assuntos
Neoplasias Pancreáticas/genética , Lesões Pré-Cancerosas/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , Animais , Apoptose/genética , Processos de Crescimento Celular/genética , Feminino , Haploidia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neoplasias Pancreáticas/enzimologia , Neoplasias Pancreáticas/patologia , Lesões Pré-Cancerosas/enzimologia , Lesões Pré-Cancerosas/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo
7.
Cancer Res ; 69(2): 678-86, 2009 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-19147584

RESUMO

Transforming growth factor-beta (TGF-beta) signaling is frequently altered in colorectal cancer. Using a novel model of mice heterozygous for a targeted null mutation of Tgfbr1 crossed with Apc(Min/+) mice, we show that Apc(Min/+);Tgfbr1(+/-) mice develop twice as many intestinal tumors as Apc(Min/+);Tgfbr1(+/+) mice, as well as adenocarcinoma of the colon, without loss of heterozygosity at the Tgfbr1 locus. Decreased Smad2 and Smad3 phosphorylation and increased cellular proliferation are observed in the colonic epithelium crypts of Apc(Min/+); Tgfbr1(+/-) mice. Smad-mediated TGF-beta signaling is preserved in both Apc(Min/+);Tgfbr1(+/+) and Apc(Min/+);Tgfbr1(+/-) intestinal tumors, but cyclin D1 expression and cellular proliferation are significantly higher in Apc(Min/+);Tgfbr1(+/-) tumors. These results show that constitutively reduced Tgfbr1-mediated TGF-beta signaling significantly enhances colorectal cancer development and results in increased tumor cell proliferation. These findings provide a plausible molecular mechanism for colorectal cancer development in individuals with constitutively altered TGFBR1 expression, a recently identified common form of human colorectal cancer.


Assuntos
Neoplasias Colorretais/genética , Proteínas Serina-Treonina Quinases/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , Animais , Processos de Crescimento Celular/fisiologia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Feminino , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Hematopoese , Endogamia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Serina-Treonina Quinases/biossíntese , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/biossíntese , Transdução de Sinais , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta/metabolismo
8.
J Rheumatol ; 35(12): 2376-8, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18925687

RESUMO

OBJECTIVE: We previously showed that Adamantiades-Behçet's disease (A-BD) is associated with a lower incidence of malignancy compared with the general population. Transforming growth factor-beta (TGF-beta) has been shown to play a role in cartilage regeneration and is increased in patients with A-BD. We also found 2 functional polymorphisms of the TGF-beta pathway, TGFBR1*6A and TGFB1*CC, that are associated with risk of malignancy. We tested whether incidence of these polymorphisms would differ in patients with A-BD compared with healthy controls of similar age and geographic location. METHODS: We performed a case-control study including 139 cases and 128 controls from Greece. Cases and controls were genotyped for TGFBR1*6A and TGFB1*CC. RESULTS: We found that cases had lower incidence of TGFBR1*6A compared with controls (11.3% vs 13.3%, respectively). Also, the incidence of TGFB1*CC was lower in cases than controls (24.6% vs 27.0%, respectively). These differences were not statistically significant. CONCLUSION: Although there is a suggestion that the lower incidence of TGFBR1*6A in A-BD patients may play a protective role against development of malignancy, larger studies would be needed to fully evaluate the role of TGF-beta and its polymorphisms in A-BD.


Assuntos
Síndrome de Behçet/genética , Predisposição Genética para Doença/genética , Proteínas Serina-Treonina Quinases/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , Fator de Crescimento Transformador beta1/genética , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética , Receptor do Fator de Crescimento Transformador beta Tipo I , Adulto Jovem
9.
JAMA ; 300(13): 1523-31, 2008 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-18827209

RESUMO

CONTEXT: Current epidemiological evidence suggests an association between obesity, hyperinsulinemia, and colorectal cancer risk. Adiponectin is a hormone secreted by the adipose tissue, and serum levels are inversely correlated with obesity and hyperinsulinemia. While there is evidence of an association between circulating adiponectin levels and colorectal cancer risk, no association between genes of the adiponectin pathway and colorectal cancer have been reported to date. OBJECTIVE: To determine the association of 10 haplotype-tagging single-nucleotide polymorphisms (SNPs) of the adiponectin (ADIPOQ) and adiponectin receptor 1 (ADIPOR1) genes with colorectal cancer risk. DESIGN, SETTING, AND PATIENTS: Two case-control studies including patients with a diagnosis of colorectal cancer and controls were recruited between 2000 and 2007. Case-control study 1 included a total of 441 patients with a diagnosis of colorectal cancer and 658 controls; both groups were of Ashkenazi Jewish ancestry and from New York, New York. Case-control study 2 included 199 patients with a diagnosis of colorectal cancer and 199 controls from Chicago, Illinois, matched 1:1 for sex, age, and ethnicity. MAIN OUTCOME MEASURES: ADIPOQ and ADIPOR1 SNP frequency among cases and controls. RESULTS: In study 1, after adjustment for age, sex, and SNPs from the same gene, 3 ADIPOQ SNPs and 1 ADIPOR1 SNP were associated with colorectal cancer risk: rs266729 (adjusted odds ratio [AOR], 0.72; 95% confidence interval [CI], 0.55-0.95) and rs822396 (AOR, 0.37; 95% CI, 0.14-1.00) were associated with decreased risk whereas rs822395 (AOR, 1.76; 95% CI, 1.09-2.84) and rs1342387 (AOR, 1.79; 95% CI, 1.18-2.72) were associated with increased risk. In study 2, after adjustment for age, sex, race, and SNPs from the same gene, the ADIPOQ SNP rs266729 was associated with a decreased colorectal cancer risk of similar magnitude as in study 1 (AOR, 0.52; 95% CI, 0.34-0.78). Combined analysis of both studies shows an association of rs266729 with decreased colorectal cancer risk (AOR, 0.73; 95% CI, 0.53-0.99). CONCLUSION: The SNP rs266729, which tags the 5' flanking region of the ADIPOQ gene, is associated with decreased colorectal cancer risk.


Assuntos
Adiponectina/genética , Neoplasias Colorretais/genética , Polimorfismo de Nucleotídeo Único , Receptores de Adiponectina/genética , Região 5'-Flanqueadora , Adulto , Idoso , Sequência de Bases , Estudos de Casos e Controles , Neoplasias Colorretais/epidemiologia , Feminino , Humanos , Judeus/genética , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Fatores de Risco
10.
Science ; 321(5894): 1361-5, 2008 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-18703712

RESUMO

Much of the genetic predisposition to colorectal cancer (CRC) in humans is unexplained. Studying a Caucasian-dominated population in the United States, we showed that germline allele-specific expression (ASE) of the gene encoding transforming growth factor-beta (TGF-beta) type I receptor, TGFBR1, is a quantitative trait that occurs in 10 to 20% of CRC patients and 1 to 3% of controls. ASE results in reduced expression of the gene, is dominantly inherited, segregates in families, and occurs in sporadic CRC cases. Although subtle, the reduction in constitutive TGFBR1 expression alters SMAD-mediated TGF-beta signaling. Two major TGFBR1 haplotypes are predominant among ASE cases, which suggests ancestral mutations, but causative germline changes have not been identified. Conservative estimates suggest that ASE confers a substantially increased risk of CRC (odds ratio, 8.7; 95% confidence interval, 2.6 to 29.1), but these estimates require confirmation and will probably show ethnic differences.


Assuntos
Neoplasias Colorretais/genética , Expressão Gênica , Predisposição Genética para Doença , Proteínas Serina-Treonina Quinases/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , Regiões 3' não Traduzidas , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Linhagem Celular , Feminino , Haplótipos , Heterozigoto , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Característica Quantitativa Herdável , Receptor do Fator de Crescimento Transformador beta Tipo I , Fatores de Risco , Transdução de Sinais , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta/metabolismo
11.
Cancer Res ; 68(9): 3178-84, 2008 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-18451143

RESUMO

Breast cancer risk is higher among obese women and women with diabetes. Adiponectin is a protein exclusively secreted by adipose tissue, circulating levels of which have been associated with breast cancer risk. Whether genetic variants within the adiponectin pathway are associated with breast cancer risk is unknown. To explore the association of genetic variants of the adiponectin (ADIPOQ) and adiponectin receptor 1 (ADIPOR1) genes with breast cancer risk, we conducted a case control study of female patients with breast cancer and healthy female controls from New York City recruited between 1999 and 2004. We genotyped 733 hospital-based breast cancer cases and 839 controls for 10 haplotype-tagging single nucleotide polymorphisms (SNP) of ADIPOQ and ADIPOR1. Two ADIPOQ SNPs (rs2241766 and rs1501299), which have been associated with circulating levels of adiponectin, were associated with breast cancer risk [rs1501299*GG: odd ratios (OR), 1.80; 95% confidence interval (95% CI), 1.14-2.85; rs2241766*TG: OR, 0.61; 95% CI, 0.46-0.80]. One ADIPOR1 SNP (rs7539542), which modulates expression of adiponectin receptor 1 mRNA, was also associated with breast cancer risk (OR, 0.51; 95% CI, 0.28-0.92). Based on the known function of rs2241766 and rs1501299, we categorized individuals by adiponectin signaling status and found that, when compared with high signalers, intermediate signalers had a 4.16-fold increase in breast cancer risk (95% CI, 0.49-35.19), and low signalers had a 6.56-fold increase in breast cancer risk (95% CI, 0.78-54.89; P(trend) = 0.001). This is the first report of an association between functionally relevant variants of the adiponectin pathway and breast cancer risk. The results warrant further studies of the adiponectin pathway in breast cancer.


Assuntos
Adiponectina/genética , Neoplasias da Mama/genética , Polimorfismo de Nucleotídeo Único , Receptores de Adiponectina/genética , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Haplótipos , Humanos , Desequilíbrio de Ligação , Pessoa de Meia-Idade , Fatores de Risco , Transdução de Sinais/genética
12.
Hum Mol Genet ; 16(24): 3128-35, 2007 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-17890272

RESUMO

TGFBR1*6A is a common hypomorphic variant of the type I transforming growth factor (TGF)-beta receptor (TGFBR1), which transduces TGF-beta growth inhibitory signals less effectively than TGFBR1. Recent studies suggest that TGFBR1*6A confers a selective growth advantage to both normal appearing and cancerous epithelial cells in the presence of TGF-beta. We have previously shown that TGFBR1*6A is somatically acquired in head and neck and colon cancer (10). Using microdissected tissues, we show that TGFBR1*6A is somatically acquired by stromal and epithelial cells adjacent to colorectal and head and neck tumors. Somatic acquisition of the TGFBR1*6A allele is not accompanied by acquisition of other tumor-specific mutations. Furthermore, lymphocytes located within the stroma or the normal appearing epithelium do not have evidence of TGFBR1*6A acquisition. The highest TGFBR1*6A/TGFBR1 allelic ratio is observed at the tumor's edge, and traces of TGFBR1*6A are detected as far as 2 cm away from the tumor, which is suggestive of centrifugal spread of cells that harbor TGFBR1*6A. Assessment of CDH1 and CDH2 expression does not indicate epithelial-mesenchymal transformation. The results suggest that TGFBR1*6A somatic acquisition is a critical event in the early stages of cancer development that is associated with field cancerization. They also represent the first human report of somatically acquired altered stromal TGF-beta signaling during oncogenesis and the first report of a concordant mutation in the stromal and epithelial compartments in colon cancer.


Assuntos
Transformação Celular Neoplásica/genética , Neoplasias do Colo/genética , Células Epiteliais/metabolismo , Neoplasias de Cabeça e Pescoço/genética , Proteínas Serina-Treonina Quinases/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , Células Estromais/metabolismo , Sequência de Bases , Neoplasias do Colo/patologia , Análise Mutacional de DNA , Células Epiteliais/patologia , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único , Receptor do Fator de Crescimento Transformador beta Tipo I , Células Estromais/patologia
13.
J Immunol ; 176(8): 4880-7, 2006 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-16585583

RESUMO

By interacting with MHC class II molecules, CD4 facilitates lineage development as well as activation of Th cells. Expression of physiological levels of CD4 requires a proximal CD4 enhancer to stimulate basic CD4 promoter activity. T cell factor (TCF)-1/beta-catenin pathway has previously been shown to regulate thymocyte survival via up-regulating antiapoptotic molecule Bcl-xL. By both loss and gain of function studies, in this study we show additional function of TCF-1/beta-catenin pathway in the regulation of CD4 expression in vivo. Mice deficient in TCF-1 displayed significantly reduced protein and mRNA levels of CD4 in CD4+ CD8+ double-positive (DP) thymocytes. A transgene encoding Bcl-2 restored survival but not CD4 levels of TCF-1(-/-) DP cells. Thus, TCF-1-regulated survival and CD4 expression are two separate events. In contrast, CD4 levels were restored on DP TCF-1(-/-) cells by transgenic expression of a wild-type TCF-1, but not a truncated TCF-1 that lacks a domain required for interacting with beta-catenin. Furthermore, forced expression of a stabilized beta-catenin, a coactivator of TCF-1, resulted in up-regulation of CD4. TCF-1 or stabilized beta-catenin greatly stimulated activity of a CD4 reporter gene driven by a basic CD4 promoter and the CD4 enhancer. However, mutation of a potential TCF binding site located within the enhancer abrogated TCF-1 and beta-catenin-mediated activation of CD4 reporter. Finally, recruitment of TCF-1 to CD4 enhancer was detected in wild-type but not TCF-1 null mice by chromatin-immunoprecipitation analysis. Thus, our results demonstrated that TCF/beta-catenin pathway enhances CD4 expression in vivo by recruiting TCF-1 to stimulate CD4 enhancer activity.


Assuntos
Antígenos CD4/genética , Fator 1 de Transcrição de Linfócitos T/metabolismo , beta Catenina/metabolismo , Animais , Sequência de Bases , Sítios de Ligação/genética , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , DNA/genética , DNA/metabolismo , Elementos Facilitadores Genéticos , Regulação da Expressão Gênica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fator 1 de Transcrição de Linfócitos T/deficiência , Fator 1 de Transcrição de Linfócitos T/genética , Transcrição Gênica , beta Catenina/genética
14.
J Mol Biol ; 355(3): 347-59, 2006 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-16309697

RESUMO

Activation of T lymphocytes requires protein kinase C theta (PKC-theta) and an appropriately elevated free intracellular Ca2+ concentration ([Ca2+]i). Here, we show that phorbol 12 myristate 13-acetate (PMA) inhibited Ca2+ influx in wild-type but not PKC-theta-/- T cells, suggesting that PKC-theta plays a role in PMA-mediated inhibition of Ca2+ influx. In contrast, T cell receptor (TCR) crosslinking in the same PKC-theta-/- T cells did result in significantly decreased [Ca2+]i compared to wild-type T cells, suggesting a positive role for PKC-theta in TCR-mediated Ca2+ mobilization. In PKC-theta-/- mice, peripheral mature T cells, but not developing thymocytes, displayed significantly decreased TCR-induced Ca2+ influx and nuclear factor of activated T cells (NFAT) translocation upon sub-optimal TCR crosslinking. The decreased intracellular free Ca2+ was due to changes in Ca2+ influx but not efflux, as observed in extracellular and intracellular Ca2+ mobilization studies. However, these differences in Ca2+ influx and nuclear factor of activated T cells (NFAT) translocation disappeared with increasing intensity of TCR crosslinking. The enhancing effect of PKC-theta on Ca2+ influx is not only dependent on the strength of TCR crosslinking but also on the developmental stage of T cells. The underlying mechanism involved phospholipase Cgamma1 activation and inositol triphosphate production. Furthermore, knockdown of endogenous PKC-theta expression in Jurkat cells resulted in significant inhibition of TCR-induced activation of NFAT, as evidenced from NFAT reporter studies. Forced expression of a constitutively active form of calcineurin in PKC-theta-/- Jurkat cells could readily overcome the above inhibition. Thus, PKC-theta can both positively and negatively regulate the Ca2+ influx that is critical for NFAT activity.


Assuntos
Cálcio/metabolismo , Isoenzimas/fisiologia , Fatores de Transcrição NFATC/metabolismo , Proteína Quinase C/fisiologia , Linfócitos T/metabolismo , Animais , Calcineurina/metabolismo , Diferenciação Celular , Reagentes de Ligações Cruzadas/metabolismo , Ativação Enzimática , Humanos , Técnicas In Vitro , Fosfatos de Inositol/metabolismo , Isoenzimas/genética , Células Jurkat , Camundongos , Camundongos Knockout , NF-kappa B/metabolismo , Fatores de Transcrição NFATC/fisiologia , Fosfolipase C gama/metabolismo , Proteína Quinase C/genética , Proteína Quinase C-theta , Transporte Proteico , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Acetato de Tetradecanoilforbol/farmacologia , Fator de Transcrição AP-1/metabolismo
15.
J Immunol ; 175(12): 7981-8, 2005 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-16339534

RESUMO

CD4+CD8+ double-positive (DP) thymocytes, which are extremely sensitive to apoptosis, specifically up-regulate Bcl-xL to extend their lifespan. Deletion of the Bcl-xL gene leads to premature apoptosis of the thymocytes. In this study, we show that stabilization of beta-catenin, a critical coactivator for T cell factor (TCF), enhances DP thymocyte survival via up-regulating Bcl-xL. Spontaneous or glucocorticoid-induced thymocyte apoptosis was associated with reduced levels of beta-catenin and Bcl-xL. Transgenic expression of a stabilized beta-catenin protected DP thymocytes from both spontaneous and glucocorticoid-induced apoptosis, resulting in significantly increased thymic cellularity. Compared with the wild-type mice, both protein and transcript levels of Bcl-xL were significantly increased in thymocytes of beta-catenin transgenic mice. In addition, TCF-1 as well as beta-catenin were able to stimulate transcriptional activity of the reporter driven by a Bcl-xL promoter. beta-Catenin/TCF is thus able to act as a signal to up-regulate Bcl-xL levels in DP thymocytes, resulting in their enhanced survival.


Assuntos
Timo/citologia , Regulação para Cima , Proteína bcl-X/genética , beta Catenina/fisiologia , Animais , Apoptose , Sobrevivência Celular , Glucocorticoides/farmacologia , Camundongos , Camundongos Transgênicos , Regiões Promotoras Genéticas , RNA Mensageiro/análise , Fator 1 de Transcrição de Linfócitos T/fisiologia , Linfócitos T/citologia , Transcrição Gênica , Proteína bcl-X/análise , beta Catenina/genética
16.
J Immunol ; 175(6): 3800-9, 2005 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-16148126

RESUMO

Thymocytes undergo apoptosis unless a functional TCR is assembled. Steroid receptor coactivators (SRCs) regulate nuclear receptor-mediated transcription by associated histone acetyltransferase activity. However, it has been a challenge to demonstrate the in vivo function of SRCs due to the overlapping functions among different members of SRCs. In this study, we show that recruitment of SRCs is required for thymic-specific retinoic acid-related orphan receptor gamma (RORgamma)t-regulated thymocyte survival in vivo. An activation function 2 domain, identified at the carboxyl terminus of RORgammat, is responsible for recruiting SRCs. A mutation in the activation function domain (Y479F) of RORgammat disrupted the interaction with SRCs and abolished RORgammat-mediated trans-activation but not its ability to inhibit transcription. Transgenes encoding the wild-type RORgammat, but not the mutant, restored thymocyte survival in RORgamma null mice. Our results thus clearly demonstrate that RORgammat recruits SRCs to impose a gene expression pattern required to expand the life span of thymocytes in vivo, which increases the opportunities for assembling a functional TCR.


Assuntos
Receptores do Ácido Retinoico/fisiologia , Receptores de Esteroides/metabolismo , Receptores dos Hormônios Tireóideos/fisiologia , Timo/citologia , Fatores de Transcrição/metabolismo , Motivos de Aminoácidos , Animais , Sítios de Ligação , Sobrevivência Celular , Regulação da Expressão Gênica , Humanos , Camundongos , Camundongos Transgênicos , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares , Ligação Proteica , Receptores de Antígenos de Linfócitos T , Receptores do Ácido Retinoico/genética , Receptores do Ácido Retinoico/metabolismo , Receptores dos Hormônios Tireóideos/genética , Receptores dos Hormônios Tireóideos/metabolismo , Ativação Transcricional
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