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1.
Materials (Basel) ; 14(21)2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34772110

RESUMO

Due to the nonlinear material behavior and contradicting application requirements, the selection of a specific electrical steel grade for a highly efficient electrical machine during its design stage is challenging. With sufficient knowledge of the correlations between material and magnetic properties and capable material models, a material design for specific requirements can be enabled. In this work, the correlations between magnetization behavior, iron loss and the most relevant material parameters for non-oriented electrical steels, i.e., alloying, sheet thickness and grain size, are studied on laboratory-produced iron-based electrical steels of 2.4 and 3.2 wt % silicon. Different final thicknesses and grain sizes for both alloys are obtained by different production parameters to produce a total of 21 final material states, which are characterized by state-of-the-art material characterization methods. The magnetic properties are measured on a single sheet tester, quantified up to 5 kHz and used to parametrize the semi-physical IEM loss model. From the loss parameters, a tailor-made material, marked by its thickness and grain size is deduced. The influence of different steel grades and the chance of tailor-made material design is discussed in the context of an exemplary e-mobility application by performing finite-element electrical machine simulations and post-processing on four of the twenty-one materials and the tailor-made material. It is shown that thicker materials can lead to fewer iron losses if the alloying and grain size are adapted and that the three studied parameters are in fact levers for material design where resources can be saved by a targeted optimization.

2.
Acta Obstet Gynecol Scand ; 100(6): 1148-1154, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33705566

RESUMO

INTRODUCTION: MicroRNAs (miRNAs) are noncoding RNAs that regulate gene expression and contribute to the development of cancer. They have been shown to be stable in tissue samples and may be promising diagnostic biomarkers for endometrial cancer. MATERIAL AND METHODS: A retrospective cohort study of women diagnosed with endometrial cancer between January 2017 and December 2017 was performed at the Royal Cornwall Hospital. Archived formalin-fixed paraffin-embedded samples were obtained from patients with endometrial cancer and healthy women. MicroRNA was isolated and quantitative real-time polymerase chain reaction was used to detect expression levels of miRNAs. RESULTS: A total of 76 women were included: 36 endometrial cancer patients, 40 healthy controls. A distinct panel of miR-200a, miR-200b, miR-200c, miR-205, and miR-182 showed an area under the curve of 0.958, sensitivity 92%, specificity 89%, positive predictive value of 89% (95% CI 82%-94%) and negative predictive value of 91% (95% CI 85%-96%) in diagnosing endometrial cancer. High miR-182 expression levels were significantly related to high-grade endometrioid tumors compared with low-grade tumors. CONCLUSIONS: We demonstrated high diagnostic accuracy of miRNA for detecting endometrial cancer. In addition, miRNA contributed to an improvement in distinguishing between high-grade and low-grade endometrioid tumors.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma Endometrioide/diagnóstico , Transformação Celular Neoplásica/genética , Neoplasias do Endométrio/diagnóstico , Regulação Neoplásica da Expressão Gênica/genética , MicroRNAs/genética , Adulto , Biomarcadores Tumorais/metabolismo , Carcinoma Endometrioide/genética , Estudos de Casos e Controles , Transformação Celular Neoplásica/metabolismo , Neoplasias do Endométrio/genética , Feminino , Perfilação da Expressão Gênica/métodos , Alemanha , Humanos , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Inclusão em Parafina , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Adulto Jovem
3.
Endocr Connect ; 9(12): 1156-1167, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33112831

RESUMO

Breast cancer (BC) represents the most common type of cancer in females worldwide. Endocrine therapy evolved as one of the main concepts in treatment of hormone-receptor positive BC. Current research focuses on the elucidation of tumour resistance mechanisms against endocrine therapy. In a translational in vitro approach, potential regulatory effects of clinically implemented BC anti-oestrogens on ERα, its coactivators DDX5, DDX17 and other DEADbox proteins as well as on the proliferation markers cyclin D1 and Ki67 were investigated on both the RNA and protein level. BC in vitro models for hormone-receptor positive (MCF-7, T-47D) and hormone-receptor negative cells (BT-20) were subjected to endocrine therapy. Anti-oestrogen-dependent expression regulation of target genes on the transcriptional and translational level was quantified and statistically assessed. Endocrine therapy decreases the expression levels of Ki67, cyclin D1 and ERα in hormone-receptor positive cells. In the hormone-receptor negative cells, the three parameters remained stable after endocrine therapy. Endoxifen triggers a downregulation of DDX5 and DDX23 in MCF-7 cells. Fulvestrant treatment downregulates the expression levels of all investigated DEADbox proteins in MCF-7 cells. In T-47D cells, endoxifen and fulvestrant lead to a decrease of all target gene expression levels. Interestingly, endocrine therapy affects DEADbox RNA expression levels in BT-20 cells, too. However, this result could only be confirmed for DDX1, immunocytologically. The investigated DEADbox proteins appear to correlate with the oestrogen-dependent tumourigenesis in hormone-receptor positive BC and show expression alterations after endocrine treatment.

4.
Cancer Biomark ; 27(2): 225-242, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32083575

RESUMO

BACKGROUND: Deregulated microRNAs (miRNAs) in breast and gynecological cancer might contribute to improve early detection of female malignancies. OBJECTIVE: Specification of miRNA types in serum and urine as minimally-invasive biomarkers for breast (BC), endometrial (EC) and ovarian cancer (OC). METHODS: In a discovery phase, serum and urine samples from 17 BC, five EC and five OC patients vs. ten healthy controls (CTRL) were analyzed with Agilent human miRNA microarray chip. Selected miRNA types were further investigated by RT-qPCR in serum (31 BC, 13 EC, 15 OC patients, 32 CTRL) and urine (25 BC, 10 EC, 10 OC patients, 30 CTRL) applying two-sample t-tests. RESULTS: Several miRNA biomarker candidates exhibited diagnostic features due to distinctive expression levels (serum: 26; urine: 22). Among these, miR-518b, -4719 and -6757-3p were found specifically deregulated in BC serum. Four, non-entity-specific, novel biomarker candidates with unknown functional roles were identified in urine (miR-3973; -4426; -5089-5p and -6841). RT-qPCR identified miR-484/-23a (all p⩽ 0.001) in serum as potential diagnostic markers for EC and OC while miR-23a may also serve as an endogenous control in BC diagnosis. CONCLUSIONS: Promising miRNAs as liquid biopsy-based tools in the detection of BC, EC and OC qualified for external validation in larger cohorts.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Neoplasias do Endométrio/genética , Neoplasias Ovarianas/genética , Idoso , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/urina , Neoplasias da Mama/sangue , Neoplasias da Mama/patologia , Neoplasias da Mama/urina , Estudos de Casos e Controles , Neoplasias do Endométrio/sangue , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/urina , Feminino , Humanos , Biópsia Líquida/métodos , Pessoa de Meia-Idade , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/urina , Prognóstico
5.
Oncol Lett ; 14(2): 2334-2340, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28789451

RESUMO

Tumor resistance to endocrine therapy triggers estrogen-independent cancer progression, which is a major obstacle to the successful treatment of hormone receptor positive breast cancer (BC). The underlying molecular mechanisms of endocrine resistance are not fully understood yet. The matricellular protein cysteine-rich angiogenic inducer 61 (Cyr61) is associated with tumor invasiveness and the induction of tumorigenesis in various malignancies in vivo and the induction of estrogen-independence and endocrine therapy resistance in BC. The present study evaluated the potential effects and clinical relevance of Cyr61 expression levels in 67 patients with primary non-metastatic BC. Immunohistochemical analysis of formalin-fixed paraffin-embedded tissue sections was performed, and the association between Cyr61 protein expression and clinicopathological factors and survival was analyzed. Cyr61 overexpression was revealed to be significantly associated with a positive estrogen receptor (ER)/progesterone receptor (PR) status (P=0.016) and to the molecular subtype of BC (P=0.039). Compared with patients without Cyr61 overexpression, patients with Cyr61 overexpression exhibited an increased recurrence rate (30.6 vs. 22.6%) and decreased long-term survival (10-year overall survival, 62.9 vs. 69.7%); however, these associations did not reach statistically significant levels in Cox regression model analysis. Similar results were identified in the subgroup analysis of patients with ER/PR positive BC. These results indicate that Cyr61 serves a role in the development of endocrine therapy resistance in BC and is thus a potential therapeutic target to overcome endocrine therapy resistance. However, additional long-term survival analyses with large patient populations are required.

6.
Oncol Rep ; 34(1): 423-30, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25997828

RESUMO

The proto-oncogene recepteur d'origine nantais (RON, MST1R) and its alternatively spliced variants are involved in various tumor biological processes, such as cell motility, adhesion, proliferation, apoptosis and epithelial-to-mesenchymal transition (EMT). RON overexpression and the occurrence of specific alternatively spliced RON isoforms have been detected in ovarian cancer. In the present study, we evaluated the role and regulation of cancer-related RON splicing isoforms in primary ovarian cancer. Expression of RON variants (RONΔ165, RONΔ160) was determined in 45 primary ovarian cancer and 4 physiological ovarian tissue specimens by RT-PCR and western blot analysis. The results were correlated to clinicopathological parameters. Additionally, expression of splicing factors with known involvement in RON alternative splicing regulation was examined. Increased RON levels were detected in all tumor samples (p=0.001) without differences between the primary tumors and metastases. Alternative RON variants were present in the majority of tumor samples (39 of 45; 86.67%). Potential RONΔ165 occurred more often (82.22%) than potential RONΔ160 or RONΔ155 (24.40%). Several significant correlations of RON and splicing factor expression [e.g. ASF/SFRS1 (p=0.035)] were detected. Correlations of RON expression to clinicopathological parameters were not observed. Significant splicing factor interactions (e.g. SRp55/SRp75: p<0.001) were observed in tumor samples with alternative RON splicing. Our data demonstrated upregulated RON isoform expression and significant changes in splicing factor expression in primary ovarian cancer. These findings account for an essential regulatory interplay of splicing factor-driven alterations in the RON alternative splicing pattern with subsequent tumor biological consequences in ovarian cancer.


Assuntos
Processamento Alternativo , Neoplasias Ovarianas/patologia , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo , Adulto , Idoso , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Isoformas de Proteínas/metabolismo , Proto-Oncogene Mas , Fatores de Processamento de Serina-Arginina
7.
BMC Cancer ; 15: 86, 2015 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-25884434

RESUMO

BACKGROUND: Estrogen receptor alpha (ERa/ESR1) expression is regulated by alternative splicing. Its most frequently detectable exon7 skipping isoform (ERaD7) is a dominant negative variant. Elevated expression of ERaD7 was already detected in endometrial cancer (EC), while its potential prognostic significance has not been characterized so far. Exon7 contains potential binding sites for the two functional splicing regulatory opponents, HNRNPG and HTRA2-BETA1 known to trigger opposite effects on EC outcome. This study served to elucidate the influence of HNRNPG and HTRA2-BETA1 on ERa exon7 splicing regulation and the impact of ERaD7 concentration on type 1 EC outcome. METHODS: Functional in vitro experiments for HNRNPG and HTRA2-BETA1 in regard to the regulatory impact on endogenous and exogenous ERaD7 splicing were performed. Additionally, real-time PCR determined mRNA levels of ERaD7, HNRNPG and HTRA2-BETA1 in 116 type 1 EC patients. RESULTS: HNRNPG and HTRA2-BETA1 were found to be specific regulators of ERa exon7 splicing. While HTRA2-BETA1 promoted exon7 inclusion, HNRNPG antagonized this effect by inducing exon7 skipping (p = 0.004). ERaD7 was detected in 71 out of 116 type 1 EC specimens. Statistical analyses revealed an inverse correlation between ERaD7 mRNA levels and tumor grading (p = 0.029), FIGO stage (p = 0.033) as well as lymph node metastases (p = 0.032), respectively. Furthermore, higher ERaD7 expression could be correlated to an improved disease-specific survival (p = 0.034). CONCLUSIONS: Our study demonstrates antagonistic regulatory effects of HNRNPG and HTRA2-BETA1 on ERa exon7 splicing with potential impact on type 1 EC clinical outcome due to the consecutively variable expression levels of the ERa isoform D7.


Assuntos
Neoplasias do Endométrio/genética , Neoplasias do Endométrio/patologia , Receptor alfa de Estrogênio/genética , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas de Ligação a RNA/metabolismo , Processamento Alternativo , Sítios de Ligação , Linhagem Celular Tumoral , Neoplasias do Endométrio/metabolismo , Receptor alfa de Estrogênio/química , Receptor alfa de Estrogênio/metabolismo , Éxons , Feminino , Células HeLa , Ribonucleoproteínas Nucleares Heterogêneas/genética , Humanos , Proteínas do Tecido Nervoso/genética , Prognóstico , Proteínas de Ligação a RNA/genética , Fatores de Processamento de Serina-Arginina
8.
BMC Cancer ; 15: 193, 2015 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-25886191

RESUMO

BACKGROUND: Since recent studies revealed the feasibility to detect blood-based microRNAs (miRNAs, miRs) in breast cancer (BC) patients a new field has been opened for circulating miRNAs as potential biomarkers in BC. In this pilot study, we evaluated to our knowledge for the first time whether distinct pattern of urinary miRNAs might be also applicable as innovative biomarkers for BC detection. METHODS: Urinary miRNA expression levels of nine BC-related miRNAs (miR-21, miR-34a, miR-125b, miR-155, miR-195, miR-200b, miR-200c, miR-375, miR-451) from 24 untreated, primary BC patients and 24 healthy controls were quantified by realtime-PCR. The receiver operating characteristic analyses (ROC) and logistic regression were calculated to assess discriminatory accuracy. RESULTS: Significant differences were found in the expression of four BC-associated miRNAs quantified as median miRNA expression levels. Urinary miR-155 levels were significantly higher in BC patients compared to healthy controls (1.49vs.0.25; p < 0.001). In contrast, compared to healthy controls, BC patients exhibited significantly lower urinary expression levels of miR-21 (2.27vs.5.07; p < 0.001), miR-125b (0.71vs.1.62; p < 0.001), and miR-451 (0.02vs.0.59 p = 0.004), respectively. The ROC including all miRNAs as well as the group of the four significant deregulated miRNAs separated BC patients from healthy controls with a very high (area under the receiver operating characteristic curve [AUC] = 0.932) and high accuracy (AUC = 0.887), respectively. CONCLUSIONS: We were able to demonstrate for the first time the feasibility to detect distinct BC-dependent urinary miRNA profiles. The expression levels of four urinary miRNAs were specifically altered in our cohort of BC patients compared to healthy controls. This distinct pattern offers the possibility for a specific discrimination between healthy women and primary BC patients. This sustains the potential role of urinary miRNAs as non-invasive innovative urine-based biomarkers for BC detection.


Assuntos
Biomarcadores Tumorais/urina , Neoplasias da Mama/urina , MicroRNAs/urina , Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/biossíntese , MicroRNAs/genética , Pessoa de Meia-Idade , Estadiamento de Neoplasias
9.
Mol Carcinog ; 53(11): 883-92, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23765422

RESUMO

The ubiquitously expressed splicing factor YT521 (YTHDC1) is characterized by alternatively spliced isoforms with regulatory impact on cancer-associated gene expression. Our recent findings account for the prognostic significance of YT521 in endometrial cancer. In this study, we investigated the hypoxia-dependency of YT521 expression as well as its differential isoform activities on oncological important target genes. YT521's potential regulatory influence on splicing was investigated by a minigene assay for the specific target gene CD44. Functional splicing analysis was performed by YT521 knock-down or overexpression, respectively. In addition, YT521 expression was determined under hypoxia. The two protein-generating YT521 mRNA isoforms 1 and 2 caused a comparable, specific induction of CD44v alternative splicing (P < 0.01). In a number of oncological target genes, YT521 upregulation significantly altered BRCA2 expression pattern, while YT521 knock-down created a significant regulatory impact on PGR expression, respectively. Hypoxia induced a specific switch towards the processing of two non-protein-coding mRNA variants, of which one is described for the first time in this study. The presented study underlines the comparable regulatory potential of both YT521 isoforms 1 and 2, on the investigated target genes in vivo and in vitro. Hypoxia induces a specific switch in YT521 expression pattern towards the two non-protein coding mRNA variants, the already characterized isoform 3 and the newly discovered exon 8-skipping isoform. The altered YT521 alternative splicing is functionally coupled with nonsense-mediated decay and can be interpreted as regulated unproductive splicing and transcription with consecutive impact on the processing of specific cancer-associated genes, such as BRCA2 and PGR.


Assuntos
Neoplasias/genética , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/genética , Proteínas de Ligação a RNA/biossíntese , Proteínas de Ligação a RNA/genética , Processamento Alternativo , Proteína BRCA2/biossíntese , Hipóxia Celular/genética , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Células HeLa , Humanos , Receptores de Hialuronatos/biossíntese , Receptores de Hialuronatos/genética , Peptídeos e Proteínas de Sinalização Intracelular/biossíntese , Células MCF-7 , Proteínas Nucleares/biossíntese , Isoformas de Proteínas/genética , Interferência de RNA , Fatores de Processamento de RNA , RNA Mensageiro/biossíntese , RNA Interferente Pequeno
10.
Int J Gynecol Cancer ; 23(6): 990-6, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23748175

RESUMO

OBJECTIVE: Alternative splicing represents an important nuclear mechanism in the posttranscriptional regulation of gene expression, which is frequently altered during tumorigenesis. Previously, we described marked changes in alternative splicing of the CD44 gene in ovarian and breast cancer as well as specific induction of distinct splicing factors during tumor development. The present study was focused on the expression profiles of different splicing factors, including classical serine-arginine (SR) proteins including ASF/SF2, hTra2ß1, hTra2α, and Y-box-binding protein (YB-1) in physiological and malignant epithelial ovarian tissue to evaluate their expression pattern with regard to tumor development and disease progression. MATERIALS AND METHODS: Expression levels of the different splicing factors were analyzed in physiological epithelial ovarian tissue samples, primary tumors, and metastatic samples of patients with a diagnosis of epithelial ovarian cancer using quantified reverse transcription polymerase chain reaction analysis. We examined more closely the splicing factor hTra2ß1 using Western blot analysis and immunohistochemistry. RESULTS: The analysis revealed a marked and specific induction of ASF/SF2, SRp20, hTra2ß1, and YB-1 in primary tumors as well as in their metastatic sites. However, in our patient cohort, no induction was seen for the other investigated splicing factors SRp55, SRp40, and hTra2α. CONCLUSIONS: Our results suggest a specific induction of distinct splicing factors in ovarian cancer tumorigenesis. The involvement of hTra2ß1, YB-1, SRp20, and ASF/SF2 in exon recognition and alternative splicing may be important for gene regulation of alternatively spliced genes like CD44 with potential functional consequences in this tumor type leading to progression and metastasis.


Assuntos
Processamento Alternativo , Biomarcadores Tumorais/genética , Neoplasias Ovarianas/mortalidade , Adenocarcinoma de Células Claras/genética , Adenocarcinoma de Células Claras/mortalidade , Adenocarcinoma de Células Claras/secundário , Adenocarcinoma Mucinoso/genética , Adenocarcinoma Mucinoso/mortalidade , Adenocarcinoma Mucinoso/secundário , Western Blotting , Carcinoma Papilar/genética , Carcinoma Papilar/mortalidade , Carcinoma Papilar/secundário , Estudos de Coortes , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/mortalidade , Cistadenocarcinoma Seroso/secundário , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/mortalidade , Neoplasias do Endométrio/secundário , Feminino , Seguimentos , Humanos , Técnicas Imunoenzimáticas , Gradação de Tumores , Estadiamento de Neoplasias , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Prognóstico , RNA Mensageiro/genética , Proteínas de Ligação a RNA/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Processamento de Serina-Arginina , Taxa de Sobrevida , Proteína 1 de Ligação a Y-Box/genética
11.
BMC Cancer ; 13: 271, 2013 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-23731661

RESUMO

BACKGROUND: Cancer-testis antigens (CTA) comprise a family of proteins, which are physiologically expressed in adult human tissues solely in testicular germ cells and occasionally placenta. However, CTA expression has been reported in various malignancies. CTAs have been identified by their ability to elicit autologous cellular and or serological immune responses, and are considered potential targets for cancer immunotherapy. The breast differentiation antigen NY-BR-1, expressed specifically in normal and malignant breast tissue, has also immunogenic properties. Here we evaluated the expression patterns of CTAs and NY-BR-1 in breast cancer in correlation to clinico-pathological parameters in order to determine their possible impact as prognostic factors. METHODS: The reactivity pattern of various mAbs (6C1, MA454, M3H67, 57B, E978, GAGE #26 and NY-BR-1 #5) were assessed by immunohistochemistry in a tissue micro array series of 210 randomly selected primary invasive breast cancers in order to study the diversity of different CTAs (e.g. MAGE-A, NY-ESO-1, GAGE) and NY-BR-1. These expression data were correlated to clinico-pathological parameters and outcome data including disease-free and overall survival. RESULTS: Expression of at least one CTA was detectable in the cytoplasm of tumor cells in 37.2% of the cases. NY-BR-1 expression was found in 46.6% of tumors, respectively. Overall, CTA expression seemed to be linked to adverse prognosis and M3H67 immunoreactivity specifically was significantly correlated to shorter overall and disease-free survival (p=0.000 and 0.024, respectively). CONCLUSIONS: Our findings suggest that M3H67 immunoreactivity could serve as potential prognostic marker in primary breast cancer patients. The exclusive expression of CTAs in tumor tissues as well as the frequent expression of NY-BR-1 could define new targets for specific breast cancer therapies.


Assuntos
Antígenos de Neoplasias/biossíntese , Biomarcadores Tumorais/análise , Neoplasias da Mama/metabolismo , Antígenos de Neoplasias/análise , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Intervalo Livre de Doença , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Análise Serial de Tecidos
12.
Hum Mol Genet ; 20(12): 2356-65, 2011 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-21447598

RESUMO

The matricellular protein Cysteine rich 61 (Cyr61) displays a remarkable diversity of multiple cellular functions involved in significant physiologic and pathologic processes. Cyr61 is known as an important player in tumor progression, promoting neovascularization and metastasis. Our prior investigations elucidated an oxygen-dependent Cyr61 alternative splicing process characterized by retention of its intron 3, regulating its biological function in a hypoxia-driven on/off switch mechanism. In this work, we identified extracellular acidosis as a potent inducer for altered Cyr61 alternative splicing pattern regulating Cyr61 expression. Intriguingly, splicing factor hTRA2-beta1 displayed an opposite effect on Cyr61 expression. Nuclear hTRA2-beta1 protein expression was found markedly reduced under acidic conditions. In keeping with these conclusions, we show that hTRA2-beta1 can specifically bind a 'GAAG' motif in Cyr61 exon 3 RNA, that the splicing factor displays acidosis-dependent protein localization in cellular compartments, and shRNA-mediated hTRA2-beta1 knock-down triggers the same effects on Cyr61 alternative splicing like acidosis or hypoxia. Our findings strongly support the hypothesis of a specific regulation of Cyr61 expression by hTRA2-beta1.


Assuntos
Acidose/metabolismo , Processamento Alternativo/fisiologia , Proteína Rica em Cisteína 61/genética , Proteína Rica em Cisteína 61/metabolismo , Regulação da Expressão Gênica/fisiologia , Proteínas do Tecido Nervoso/metabolismo , Proteínas de Ligação a RNA/metabolismo , Processamento Alternativo/genética , Western Blotting , Primers do DNA/genética , Regulação da Expressão Gênica/genética , Técnicas de Silenciamento de Genes , Vetores Genéticos , Humanos , Imuno-Histoquímica , Proteínas do Tecido Nervoso/genética , Proteínas de Ligação a RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Processamento de Serina-Arginina
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