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1.
Cogn Res Princ Implic ; 9(1): 27, 2024 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-38700660

RESUMEN

The .05 boundary within Null Hypothesis Statistical Testing (NHST) "has made a lot of people very angry and been widely regarded as a bad move" (to quote Douglas Adams). Here, we move past meta-scientific arguments and ask an empirical question: What is the psychological standing of the .05 boundary for statistical significance? We find that graduate students in the psychological sciences show a boundary effect when relating p-values across .05. We propose this psychological boundary is learned through statistical training in NHST and reading a scientific literature replete with "statistical significance". Consistent with this proposal, undergraduates do not show the same sensitivity to the .05 boundary. Additionally, the size of a graduate student's boundary effect is not associated with their explicit endorsement of questionable research practices. These findings suggest that training creates distortions in initial processing of p-values, but these might be dampened through scientific processes operating over longer timescales.


Asunto(s)
Estadística como Asunto , Humanos , Adulto , Adulto Joven , Interpretación Estadística de Datos , Masculino , Psicología , Femenino
2.
J Speech Lang Hear Res ; 66(9): 3413-3427, 2023 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-37591234

RESUMEN

PURPOSE: The /ɹ/ productions of young children acquiring American English are highly variable and often inaccurate, with [w] as the most common substitution error. One acoustic indicator of the goodness of children's /ɹ/ productions is the difference between the frequency of the second formant (F2) and the third formant (F3), with a smaller F3-F2 difference being associated with a perceptually more adultlike /ɹ/. This study analyzed the effectiveness of automatically extracted F3-F2 differences in characterizing young children's productions of /ɹ/-/w/ in comparison with manually coded measurements. METHOD: Automated F3-F2 differences were extracted from productions of a variety of different /ɹ/- and /w/-initial words spoken by 3- to 4-year-old monolingual preschoolers (N = 117; 2,278 tokens in total). These automated measures were compared to ratings of the phoneme goodness of children's productions as rated by untrained adult listeners (n = 132) on a visual analog scale, as well as to narrow transcriptions of the production into four categories: [ɹ], [w], and two intermediate categories. RESULTS: Data visualizations show a weak relationship between automated F3-F2 differences with listener ratings and narrow transcriptions. Mixed-effects models suggest the automated F3-F2 difference only modestly predicts listener ratings (R 2 = .37) and narrow transcriptions (R 2 = .32). CONCLUSION: The weak relationship between automated F3-F2 difference and both listener ratings and narrow transcriptions suggests that these automated acoustic measures are of questionable reliability and utility in assessing preschool children's mastery of the /ɹ/-/w/ contrast.


Asunto(s)
Acústica , Instituciones Académicas , Adulto , Humanos , Preescolar , Reproducibilidad de los Resultados , Escolaridad
3.
Top Cogn Sci ; 14(2): 414-425, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34779579

RESUMEN

Traditional statistics instruction emphasizes a .05 significance level for hypothesis tests. Here, we investigate the consequences of this training for researchers' mental representations of probabilities - whether .05 becomes a boundary, that is, a discontinuity of the mental number line, and alters their reasoning about p-values. Graduate students with statistical training (n = 25) viewed pairs of p-values and judged whether they were "similar" or "different." After controlling for several covariates, participants were more likely and faster to judge p-values as "different" when they crossed the .05 boundary (e.g., .046 vs. .052) compared to when they did not (e.g., .026 vs. .032). This result suggests a categorical perception-like effect for the processing of p-values. It may be a consequence of traditional statistical instruction creating a psychologically real divide between so-called statistical "significance" and "nonsignificance." Such a distortion is undesirable given modern approaches to statistical reasoning that de-emphasize dichotomizing the p-value continuum.


Asunto(s)
Percepción , Estudiantes , Humanos , Probabilidad
4.
Drug Dev Res ; 81(3): 366-373, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31800126

RESUMEN

Seven piperic acid amides along with their lower homologs (12) were synthesized using HATU-DIPEA coupling reagent. All the synthesized derivatives were evaluated for their antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa, and vancomycin-resistant P. aeruginosa. They were found to be more active on P. aeruginosa than on S. aureus. However, they did not exhibit potent activity on Vancomycin resistant P. aeruginosa. Among the tested compounds, methylenedioxycinnamic acid amide of anthranilic acid (MDCA-AA, 2a) was found to be most active against S. aureus with MIC of 3.125 µg/ml. The PAS and INH amides of piperic acid were screened against Mycobacterium tuberculosis H37Ra strain. They were found to be most active among all the tested compounds but were found to be less active than the standard drug, isoniazid.


Asunto(s)
Amidas/farmacología , Antibacterianos/farmacología , Ácidos Grasos Insaturados/farmacología , Amidas/síntesis química , Amidas/química , Antibacterianos/síntesis química , Antibacterianos/química , Ácidos Grasos Insaturados/síntesis química , Ácidos Grasos Insaturados/química , Isoniazida/farmacología , Pruebas de Sensibilidad Microbiana , Mycobacterium tuberculosis/efectos de los fármacos , Pseudomonas aeruginosa/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Relación Estructura-Actividad
5.
Int J Chronic Dis Ther ; 2(3): 31-38, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28164176

RESUMEN

Women who carry a germline mutation in BRCA1 gene typically develop triple negative breast cancers (TNBC) and high grade serous ovarian cancers (HGSOC). Previously, we reported that wild type BRCA1 proteins, unlike the disease-associated mutant BRCA1 proteins to bind the sole sumo E2-conjugating enzyme Ubc9. In this study, we have used clinically relevant cell lines with known BRCA1 mutations and report the in-vivo association of BRCA1 and Ubc9 in normal mammary epithelial cells but not in BRCA1 mutant HGSOC and TNBC cells by immunofluorescence analysis. BRCA1-mutant HGSOC/TNBC cells and ovarian tumor tissues showed increased expression of Ubc9 compared to BRCA1 reconstituted HGSOC, normal mammary epithelial cells and matched normal ovarian tissues. Knockdown of Ubc9 expression resulted in decreased proliferation and migration of BRCA1 mutant TNBC and HGSOC cells. This is the first study demonstrating the functional link between BRCA1 mutation, high Ubc9 expression and increased migration of HGSOC and TNBC cells. High Ubc9 expression due to BRCA1 mutation may trigger an early growth and transformation advantage to normal breast and ovarian epithelial cells resulting in aggressive cancers. Future work will focus on studying whether Ubc9 expression could show a positive correlation with BRCA1 linked HGSOC and basal like TNBC phenotype.

7.
J Gynecol Res ; 1(1)2015.
Artículo en Inglés | MEDLINE | ID: mdl-26665166

RESUMEN

Ovarian cancer constitutes the second most common gynecological cancer with a five-year survival rate of 40%. Among the various histotypes associated with hereditary ovarian cancer, high-grade serous epithelial ovarian carcinoma (HGSEOC) is the most predominant and women with inherited mutations in BRCA1 have a lifetime risk of 40-60%. HGSEOC is a challenge for clinical oncologists, due to late presentation of patient, diagnosis and high rate of relapse. Ovarian tumors have a wide range of clinical presentations including development of ascites as a result of deregulated endothelial function thereby causing increased vascular permeability of peritoneal vessels. The molecular mechanisms remain elusive. Studies have shown that fallopian tube cancers develop in women with BRCA1 gene mutations more often than previously suspected. Recent studies suggest that many primary peritoneal cancers and some high-grade serous epithelial ovarian carcinomas actually start in the fallopian tubes. In this article we have addressed the molecular pathway of a recently identified potential biomarker Ubc9 whose deregulated expression due to BRCA1 dysfunction can result in HGSEOC with peritoneal permeability and formation of ascites. We also discuss the role of downstream targets Caveolin-1 and Vascular Endothelial Growth Factor (VEGF) in the pathogenesis of ascites in ovarian carcinomas. Finally we hypothesize a signaling axis between Ubc9 over expression, loss of Caveolin-1 and induction of VEGF in BRCA1 mutant HGSEOC cells. We suggest that Ubc9-mediated stimulation of VEGF as a novel mechanism underlying ovarian cancer aggressiveness and ascites formation. Agents that target Ubc9 and VEGF signaling may represent a novel therapeutic strategy to impede peritoneal growth and spread of HGSEOC.

9.
Fitoterapia ; 100: 166-73, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25481374

RESUMEN

Ten malabaricane type triterpenes were isolated from the oleoresin of Ailanthus malabarica, out of which six (1-6) were new. For three of the known compounds (7-9), NMR assignments are being reported for the first time. Compound 10, a known one, is a new report from this source. The structures were established by extensive 1D and 2D NMR spectroscopy. The oleoresin and some of the isolates did not possess antimicrobial activity and did not lyse RBCs.


Asunto(s)
Ailanthus/química , Extractos Vegetales/química , Triterpenos/química , Estructura Molecular , Triterpenos/aislamiento & purificación
10.
Indian J Lepr ; 83(2): 81-6, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21972660

RESUMEN

Bargarh district in the western Orissa had high leprosy burden and LEPRA India supported in control activities. Its main focus was on POD care with community participation. After motivation and capacity building, it transferred the responsibility of POD care to affected persons, family, community partners and GHS staff in 2006. The effectiveness of this approach was evaluated in 2009. With personal contact responses from 112 (17%) persons with disability and 18 stakeholders were obtained. Result shows 98% affected persons are staying with family; 92% are practicing self-care; 92% felt self-care is beneficial; 57% and 36% are using commercial and MCR footwear respectively. Surgical correction of deformity is maintained in 80% of cases. Difficulty in activity and in community participation was experienced in about one third of affected persons the latter is mostly due to self stigma. The facilitators were happy with their beneficiaries.


Asunto(s)
Personas con Discapacidad/rehabilitación , Lepra/rehabilitación , Autocuidado , Adolescente , Adulto , Anciano , Niño , Participación de la Comunidad , Femenino , Humanos , India , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Evaluación de Programas y Proyectos de Salud , Apoyo Social , Factores Socioeconómicos , Encuestas y Cuestionarios , Adulto Joven
11.
Vet Res Commun ; 33(7): 781-91, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19440851

RESUMEN

Comparative efficacy of faecal culture and IS900 Polymerase chain reaction (PCR) assay of faecal samples was investigated in 40 clinically suspected cases of Johne's disease in dairy cattle. The sensitivity of faecal culture and PCR assay in this study was 52.5% (21/40) and 90% (36/40) respectively. All isolates appeared only on the mycobactin J supplemented Herrold's egg yolk medium (HEYM) at 8-16 weeks post-inoculation, were acid-fast and were positive for IS900 PCR yielding a single amplicon of 217 bp. A total of 28 faecal samples out of 40 were positive by IS900 primary PCR assay for Mycobacterium avium subsp. paratuberculosis (Map) yielding an expected product of size 217 bp. Twelve faecal samples, which gave negative results in the primary PCR, were subjected to secondary PCR assay. Of the 12 samples, 8 gave positive results in the IS900 nested PCR (nPCR), which yielded a PCR product of 167 bp, proving better sensitivity of nPCR assay than single amplification PCR. PCR could detect additionally 15 samples as positive which were negative by faecal culture. The chi-square analysis showed a highly significant difference between the tests (P< 0.01). This study suggests that IS900-PCR-based detection of Map could be used as a potential diagnostic tool for rapid and effective Johne's disease surveillance.


Asunto(s)
Enfermedades de los Bovinos/microbiología , Heces/microbiología , Mycobacterium avium subsp. paratuberculosis/genética , Mycobacterium avium subsp. paratuberculosis/aislamiento & purificación , Paratuberculosis/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , Animales , Bovinos , Cartilla de ADN , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación
12.
Int J Oncol ; 34(4): 939-49, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19287951

RESUMEN

BRCA1 dysfunction is associated with hormone-responsive cancers. We have identified a consensus SUMO modification site in the amino-terminal region of BRCA1/1a/1b proteins and the mutation in this potential SUMO acceptor site (K 109 to R) impaired their ability to bind and repress ligand-dependent ERalpha transcriptional activity in breast cancer cells. Furthermore, we have found SUMO E2-conjugating enzyme Ubc9 to bind BRCA1 proteins. We have mapped BRCA1 [within amino acids (aa) 1-182] as the minimum domain that is sufficient for in vitro binding to Ubc9 as well as for regulating ERalpha activity. BRCA1 Mutant #1 (K109 to R) was impaired in its ability to both bind, as well as modulate Ubc9 mediated SUMO-dependent/independent E2-induced ERalpha transcriptional activity in breast cancer cells. Similarly, BRCA1 cancer-predisposing mutation (61Cys-Gly) abrogated the ability to both bind Ubc9 as well as inhibit ERalpha activity suggesting physiological significance. Addition of BRCA1 but not Mutant #1 to E2-induced ERalpha in the presence of SUMO-1 and Ubc9 resulted in the degradation of ERalpha suggesting BRCA1 to be a putative SUMO-1 and Ubc9-dependent E3 ubiquitin ligase for ERalpha. This is the first report demonstrating the participation of Ubc9 in BRCA1 E3 ubiquitin ligase mediated degradation of ERalpha. These results suggest a novel function for BRCA1 in regulating the dynamic cycles of SUMO and ubiquitin modifications required for ERalpha turn over and deregulation of this molecular switch due to lack of BRCA1 results in ERalpha-negative/positive breast cancers. This study will help in designing novel BRCA1 function-based targeted treatment for breast cancers.


Asunto(s)
Proteína BRCA1/genética , Proteína BRCA1/fisiología , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Receptor alfa de Estrógeno/metabolismo , Regulación Neoplásica de la Expresión Génica , Proteína SUMO-1/genética , Enzimas Ubiquitina-Conjugadoras/genética , Animales , Células COS , Línea Celular Tumoral , Chlorocebus aethiops , Humanos , Microscopía Fluorescente , Modelos Genéticos , Mutación , Proteína SUMO-1/metabolismo , Enzimas Ubiquitina-Conjugadoras/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo
13.
Oncogene ; 26(41): 6031-7, 2007 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-17384678

RESUMEN

Breast cancer gene 1 (BRCA1) mutations predispose women to breast and ovarian cancers and men to increased risks for prostate cancer. We have previously showed BRCA1 splice variant BRCA1a/p110 to induce apoptosis of human breast cancer cells. In the current study, stable expression of BRCA1a/p110 resulted in inhibition of growth of estrogen receptor (ER)-positive and triple-negative (TN) human breast, ovarian, prostate and colon cancer cells and mouse fibroblast cells. Similar to wild-type BRCA1, only those cells with wild-type Rb were sensitive to BRCA1a-induced growth suppression and the status of p53 did not affect the ability of BRCA1a to suppress growth of tumor cells. BRCA1a also significantly inhibited tumor mass in nude mice bearing human CAL-51 TN breast cancer, ES-2 ovarian cancer and PC-3 prostate cancer xenografts. These results suggest that the majority of exon 11 sequences (residues 263-1365) are not required for the tumor suppressor function of BRCA1 proteins. This is the first report demonstrating antitumor activity of BRCA1a in human ER-positive and TN breast, hormone-independent ovarian and prostate cancer cells. Currently, there are no effective treatments against TN breast cancers and results from these studies will provide new treatments for one of the biggest needs in breast cancer research.


Asunto(s)
Proteína BRCA1/genética , Neoplasias de la Mama/prevención & control , Variación Genética , Neoplasias Ováricas/prevención & control , Neoplasias de la Próstata/prevención & control , Empalme Alternativo , Animales , Apoptosis , División Celular , Femenino , Humanos , Masculino , Ratones , Ratones Desnudos , Receptores de Estrógenos/fisiología , Trasplante Heterólogo
14.
Oncogene ; 20(46): 6653-9, 2001 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-11709699

RESUMEN

The recurrent t(12;22) (q13;q12) chromosomal translocation associated with soft tissue clear cell sarcoma results in a chimeric protein EWS-ATF-1 that acts as a constitutive transcriptional activator. The CBP/p300 transcriptional coactivator, which links various transcriptional factors to basal transcription apparatus, participates in transcriptional activation, growth and cell cycle control and differentiation. In this study, we show that EWS-ATF-1 associates constitutively with CBP both in vitro and in vivo. Both EWS and ATF-1 fusion domains are needed for this interaction. Here, we demonstrate that EWS-ATF-1 represses p53/CBP-mediated trans-activation function. Overexpression of CBP can counteract this repressive effect of EWS-ATF-1. Taken together, these findings suggest that one of the mechanisms by which EWS-ATF-1 may cause tumors is through targeting CBP/p300 resulting in the loss of function of p53. This novel mechanism may be responsible for the development of these and other related solid tumors.


Asunto(s)
Genes p53 , Proteínas Nucleares/metabolismo , Proteínas de Fusión Oncogénica/metabolismo , Sarcoma de Células Claras/genética , Sarcoma de Células Claras/metabolismo , Neoplasias de los Tejidos Blandos/genética , Neoplasias de los Tejidos Blandos/metabolismo , Transactivadores/metabolismo , Activación Transcripcional , Western Blotting , Relación Dosis-Respuesta a Droga , Glutatión Transferasa/metabolismo , Humanos , Modelos Genéticos , Plásmidos/metabolismo , Pruebas de Precipitina , Unión Proteica , Estructura Terciaria de Proteína , Factores de Transcripción , Transcripción Genética , Transfección , Células Tumorales Cultivadas
15.
Oncogene ; 20(11): 1357-67, 2001 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-11313879

RESUMEN

Elk-1, a c-Fos protooncogene regulator, which belongs to the ETS-domain family of transcriptional factors, plays an important role in the induction of immediate early gene expression in response to a variety of extracellular signals. In this study, we demonstrate for the first time the in vitro and in vivo interaction of Elk-1 with BRCA1 splice variants BRCA1a and BRCA1b using GST-pull down assays, co-imunoprecipitations/Western blot analysis of cell extracts from breast cancer cells and mammalian two-hybrid assays. We have localized the BRCA1 interaction domain of Elk-1 protein to the conserved ETS domain, a motif involved in DNA binding and protein-protein interactions. We also observed binding of BRCA1 proteins to other ETS-domain transcription factors SAP1, ETS-1, ERG-2 and Fli-1 but not to Elk-1 splice variant DeltaElk-1 and c-Fos protooncogene. Both BRCA1a and BRCA1b splice variants function as growth suppressors of human breast cancer cells. Interestingly, our studies reveal that although both Elk-1 and SAP-1 are highly homologous members of a subfamily of ETS domain proteins called ternary complex factors, it is only Elk-1 but not SAP-1 that can augment the growth suppressive function of BRCA1a/1b proteins in breast cancer cells. Thus Elk-1 could be a potential downstream target of BRCA1 in its growth control pathway. Furthermore, we have observed inhibition of c-Fos promoter activity in BRCA1a transfected stable breast cancer cells and over expression of BRCA1a/1b attenuates MEK-induced SRE activation in vivo. These results demonstrate for the first time a link between the growth suppressive function of BRCA1a/1b proteins and signal transduction pathway involving Elk-1 protein. All these results taken together suggest that one of the mechanisms by which BRCA1a/1b proteins function as growth/tumor suppressors is through inhibition of the expression of Elk-1 target genes like c-Fos.


Asunto(s)
Empalme Alternativo , Proteína BRCA1/metabolismo , Neoplasias de la Mama/genética , Genes fos/genética , Proteínas Proto-Oncogénicas/metabolismo , Factores de Transcripción/metabolismo , Animales , Proteína BRCA1/genética , Neoplasias de la Mama/metabolismo , Proteínas de Unión al ADN , Femenino , Genes Supresores de Tumor , Humanos , Neoplasias Mamarias Animales/metabolismo , Neoplasias Mamarias Animales/patología , Proteína Quinasa 3 Activada por Mitógenos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteínas Nucleares , Unión Proteica , Elementos de Respuesta , Factor de Respuesta Sérica , Proteína Elk-1 con Dominio ets
16.
Oncogene ; 18(1): 263-8, 1999 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-9926942

RESUMEN

Inherited mutations in the breast and ovarian cancer susceptibility gene BRCA1 are associated with high risk for developing breast and ovarian cancers. Several studies link BRCA1 to transcriptional regulation, DNA repair, apoptosis and growth/tumor suppression. BRCA1 associates with p53 and stimulates transcription in both p53 dependent and p53-independent manners. BRCA1 splice variants BRCA1a (p110) and BRCA1b (p100) associates with CBP/p300 co-activators. Here we show that BRCA1a and BRCA1b proteins stimulate p53-dependent transcription from the p21WAF1/CIP1 promoter. In addition, the C-terminal second BRCA1 (BRCT) domain is sufficient for p53 mediated transactivation of the p21 promoter. Previous studies emphasized the importance of the BRCT domain, which shows homology with p53 binding protein (53BP1), in transcriptional activation, growth inhibition and tumor suppression. Our findings demonstrate an additional function for this domain in protein-protein interaction and co-activation of p53. We also found that BRCA1a and BRCA1b proteins interact with p53 in vitro and in vivo. The p53 interaction domain of BRCA1a/1b maps, in vitro, to the second BRCT domain (aa 1760-1863). The BRCT domain binds to the central domain of p53 which is required for sequence specific DNA binding. These results demonstrate for the first time the presence of a second p53 interaction domain in BRCA1 proteins and suggests that BRCA1a and BRCA1b proteins, like BRCA1, function as p53 co-activators. This BRCT domain also binds in vitro to CBP. These results suggest that one of the mechanisms by which BRCA1 proteins function is through recruitment of CBP/p300 associated HAT/FAT activity for acetylation of p53 to specific promoters resulting in transcriptional activation.


Asunto(s)
Proteína BRCA1/metabolismo , Ciclinas/genética , Regiones Promotoras Genéticas , Transcripción Genética , Proteína p53 Supresora de Tumor/metabolismo , Animales , Proteína BRCA1/genética , Sitios de Unión , Células COS , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Humanos , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/genética
17.
Oncol Rep ; 6(2): 437-40, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10023017

RESUMEN

BRCA1 and BRCA2 are tumor suppressor genes shown to be involved in 90% of familial breast cancers and also known to be involved in ovarian and prostate cancers. Both BRCA1 and BRCA2 gene products are regulated in a cell cycle-dependent manner and have potential transactivation function. Here, we show that BRCA2 undergoes differential splicing giving rise to a novel variant protein BRCA2a, lacking putative transcriptional activation domain. Both BRCA2a and BRCA2 are expressed at high levels in thymus and testis but moderate levels in mammary gland and prostate suggesting that BRCA2a and BRCA2 may have a role in the development and differentiation of these tissues.


Asunto(s)
Biomarcadores de Tumor/genética , Variación Genética , Proteínas de Neoplasias/genética , Eliminación de Secuencia , Factores de Transcripción/genética , Empalme Alternativo , Proteínas Reguladoras de la Apoptosis , Proteína BRCA2 , Mama/metabolismo , Clonación Molecular , Exones , Femenino , Humanos , Masculino , Especificidad de Órganos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Testículo/metabolismo , Timo/metabolismo , Activación Transcripcional
18.
Oncogene ; 17(9): 1149-57, 1998 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-9764825

RESUMEN

The proto-oncogene Fli-1, a member of Ets family is rearranged or activated through proviral integration in erythroleukemias, induced by Friends' Murine Leukemia Virus. The DNA binding domain (ETS domain) of Fli-1 is fused to the RNA binding domain of EWS by t(11q24:22q12) chromosomal translocation in Ewing's sarcoma and primitive neuroectodermal tumors. Screening of human cDNA libraries has identified two different 5'-termini and alternatively spliced forms of the human Fli-1 gene (Fli-1b), suggesting the possible existence of two independent promoters. The genomic sequence adjacent to the alternate exon of human Fli-1b gene shows functional promoter activity when cloned in promoter-less CAT expression vector and transfected into QT-6 cells. The transcription initiation (CAP) site and minimum promoter region necessary for function were localized. The 5'-flanking regions of human Fli-1b and mouse Fli-1 show 80% homology suggesting conserved promoter regulatory elements. The Fli-1b 5'-flanking sequence lacks canonical TATA or CCAAT boxes but contains a partially conserved TATA-like sequence at position 242. Several transcription factor binding sequences like ATF/CREB, E2A-PBX1, EBP, PEA-3, ETS-2, Sp-1, c-Myc, TBP, GATA-1 and Oct-3 were conserved in the promoter sequence. Functional promoter assays revealed that Fli-1b promoter shows very strong transcriptional activation compared to Fli-1 promoter. We also showed that variant Fli-1b has transcriptional activation properties similar to those of Fli-1. Fli-1b and Fli-1 show differential expression in various hematopoietic cell lines. This differential expression and promoter activities of Fli-1 and Fli-1b suggests that several mechanisms are involved in Fli-1 gene regulation which are mediated by many transcription factors.


Asunto(s)
Empalme Alternativo/genética , Proteínas de Unión al ADN/genética , Proteínas Proto-Oncogénicas , Transactivadores/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Sitios de Unión/genética , Cloranfenicol O-Acetiltransferasa/genética , ADN Complementario/química , ADN Complementario/genética , ADN Complementario/aislamiento & purificación , Proteínas de Unión al ADN/fisiología , Expresión Génica/genética , Humanos , Datos de Secuencia Molecular , Regiones Promotoras Genéticas/genética , Proto-Oncogenes Mas , Proteína Proto-Oncogénica c-fli-1 , ARN Mensajero/análisis , ARN Mensajero/genética , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Sensibilidad y Especificidad , Análisis de Secuencia de ADN , Eliminación de Secuencia/genética , Homología de Secuencia de Ácido Nucleico , TATA Box/genética , Transactivadores/fisiología , Transcripción Genética/genética , Transfección , Células Tumorales Cultivadas/citología , Células Tumorales Cultivadas/metabolismo
19.
Oncogene ; 17(4): 527-32, 1998 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-9696047

RESUMEN

Elk-1, an ets related gene codes for at least two splice variants Elk-1, which regulates c-fos transcription and deltaElk-1, both of which function as transcriptional activators. To investigate the role of Elk-1 and deltaElk-1 proteins in apoptosis; we have developed rat fibroblast cell lines and human breast cancer cell lines expressing Elk-1 and deltaElk-1. The expression of Elk-1 and deltaElk-1 proteins in the Elk-1/deltaElk-1 transfectants were analysed by immunofluorescence, immunohistochemistry, and Western blot analysis. The Elk-1 unlike deltaElk-1 transfectants showed a shortened and flattened morphology compared to the parental cells. We have found that calcium ionophore treatment of Rat-1 Elk-1, MCF-7 Elk-1, Rat-1 deltaElk-1 and MCF-7 deltaElk-1 transfectants resulted in programmed cell death. These results indicate that constitutive expression of Elk-1 and deltaElk-1 proteins triggers apoptosis in Rat-1 fibroblasts and breast cancer cells when treated with calcium ionophore.


Asunto(s)
Apoptosis , Proteínas de Unión al ADN , Proteínas Proto-Oncogénicas/fisiología , Factores de Transcripción/fisiología , Animales , Línea Celular , Femenino , Humanos , Proteínas Proto-Oncogénicas/genética , Ratas , Factores de Transcripción/genética , Células Tumorales Cultivadas , Proteína Elk-1 con Dominio ets
20.
Proc Natl Acad Sci U S A ; 95(14): 8239-44, 1998 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-9653171

RESUMEN

Many chimeric oncogenes have been identified by virtue of the association between chromosomal translocation and specific human leukemias. However, the biological mechanism by which these oncogenes disrupt the developmental program of normal human hematopoietic cells during the initiation of the leukemogenic process is poorly understood due to the absence of an appropriate experimental system to study their function. Here, we report that retroviral transduction of TLS-ERG, a myeloid leukemia-associated fusion gene, to human cord blood cells results in altered myeloid and arrested erythroid differentiation and a dramatic increase in the proliferative and self-renewal capacity of transduced myeloid progenitors. Thus, TLS-ERG expression alone induced a leukemogenic program that exhibited similarities to the human disease associated with this translocation. These results provide an experimental examination of the early stages of the human leukemogenic process induced by a single oncogene and establish a paradigm to functionally assay putative leukemogenic genes in normal human hematopoietic cells.


Asunto(s)
Transformación Celular Neoplásica/genética , Regulación Neoplásica de la Expresión Génica , Células Madre Hematopoyéticas/patología , Células Madre Hematopoyéticas/fisiología , Leucemia/genética , Leucemia/patología , Proteínas de Fusión Oncogénica/genética , Proteína FUS de Unión a ARN , Linaje de la Célula/genética , Técnicas de Transferencia de Gen , Vectores Genéticos , Hematopoyesis/genética , Humanos , Retroviridae
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