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2.
J Thorac Dis ; 14(6): 2201-2212, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35813748

RESUMO

Background: Anaplastic lymphoma kinase (ALK) gene rearrangement is a series of mutations of non-small cell lung cancer (NSCLC) patients. Since 2011, multiple ALK inhibitors (ALKis) have been developed and launched for targeted therapy. In this study, we sought to investigate different strategies of sequential applying the ALKis and their clinical benefits to the overall survival (OS). Methods: A total of 176 patients with advanced NSCLC (stage IIIB-IV) harboring the ALK rearrangement were included in this cohort study. They were diagnosed between February 1, 2012 and November 19, 2019 at Peking University Cancer Hospital. Clinical characters were reviewed from patients' records. Strategies of drugs, progression-free survival (PFS) and OS were collected during the follow-ups. The Kaplan-Meier method and multivariate Cox proportional-hazard analysis were used to conduct the analyses survival and to examine the relationship between the variables and OS. Results: A significantly longer OS was observed either in patients treated with crizotinib [N=106, median OS (mOS): 32.9 months] or in patients treated with a next-generation ALKi [N=34, mOS: not reached (NR)] as the initial ALKi, compared with patients treated with conventional chemotherapy but no ALKi (N=36, mOS: 10.3 months, P<0.001). After disease progression with initial crizotinib, patients who received no ALKi had shorter OS than those who received only crizotinib beyond progressive disease (CBPD) (mOS: 9.7 vs. 20.3 months; P=0.015), only subsequent next-generation ALKis (mOS: 9.7 vs. 41.1 months; P<0.001), and CBPD followed with subsequent next-generation ALKis (mOS: 9.7 months vs. NR; P<0.001). Patients treated with 2 types of ALKi had better survival than those treated with 1 ALKi (mOS: 45.8 vs. 21.3 months, P=0.003), but no such survival benefit was observed in patients treated with ≥3 ALKis (P=0.366). Conclusions: ALKis have been shown to be clinically effective in treating NSCLC patients with ALK rearrangements. In the case of disease progression with crizotinib, either of CBPD or sequential other ALKis can extend patients' OS. The sequential application of multiple ALKis was found to be better than it of single ALKi in prolonging OS. However, the question of which inhibitor to select as the initial inhibitor needs to be examined further in future studies.

3.
Front Oncol ; 12: 974654, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36703795

RESUMO

Introduction: Colorectal cancer (CRC) is a serious threat to human health. Screening new biomarkers can provide basis for improving the prognosis and individualized treatment of CRC. Although some members of the defensin family were found increased in pancreatic cancer and CRC, their exact function and clinical significance remain unclear. Methods: In this study, the expression, correlation, mutation, and functional enrichment of several defensin family members in pancreatic cancer and CRC were analyzed using tumor public databases and verified in several patients. Results: Results showed no significant correlation between the expression levels of DEFA1-4 and CRC. The expression levels of DEFA5 and DEFA6 significantly increased in CRC tissues compared with those in normal tissues. DEFA5 may be associated with better prognosis of CRC, while DEFA6 may be associated with poor prognosis. Immunohistochemistry (IHC) experiments showed that the expression of DEFA6 was significantly higher in adenoma than in normal mucosa and slightly higher in carcinoma than in normal mucosa. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis found that DEFAs were closely related to hsa05202: transcriptional misregulation in cancer and Hsa04015: Rap1 signaling pathway. DEFA5 may be a stable and good prognostic marker, and DEFA6 may be a poor prognostic marker in CRC of metastasis. Conclusion: Overall, DEFA5 and DEFA6 have a certain degree of sensitivity and specificity in predicting CRC.

4.
Prog Biophys Mol Biol ; 163: 34-45, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33610681

RESUMO

FOXI1 plays a key role in the development of gastric cancer. However, the whole genome FOXI1 binding sites and its target genes are unclear. In the present study, we used ChIP-seq and RNA-seq technologies to identify the target gene of FOXI1. Firstly, ChIP-seq data showed that, 4476 unique peaks in the genome region were captured. Most of these binding peaks are located in introns or intergenic regions. We annotated all the peaks to the nearest gene and identified 404 genes as FOXI1 binding genes. KEGG and GO analysis showed that FOXI1 binding gene to be correlated with the cellular process, cell part, cell, binding, single-organism process. Further, we performed FOXI1-overexpressed RNA-seq experiment. We comprehensively analyzed the ChIP-seq and RNA-seq data and take the intersection of two databases, several genes were identified. ATF3 was selected from the intersection since ATF3 was the most enriched mRNA after FOXI1 overexpressed. ChIP-qPCR and luciferase report gene were used to validate that ATF3 was target gene of FOXI1. Intriguely, ATF3 protein was significantly downregulated after FOXI1 overexpressed. We found FOXI1 can also bind to the promoter of miR-590 and active it which directly target ATF3. The binding site between FOXI1 and miR-590 was verified by ChIP-qPCR and luciferase report gene, and the target relationship between miR-590 and ATF3 was confirmed by dual-luciferase reporter gene. In conclusion, our data identified the genome binding sites of FOXI1, and provide evidence that FOXI1 inhibits gastric cancer cell proliferation by activating miR-590/ATF3 axis.


Assuntos
MicroRNAs , Neoplasias Gástricas , Fator 3 Ativador da Transcrição/genética , Proliferação de Células/genética , Sequenciamento de Cromatina por Imunoprecipitação , Fatores de Transcrição Forkhead , Humanos , MicroRNAs/genética , RNA-Seq , Neoplasias Gástricas/genética
5.
Future Oncol ; 12(10): 1243-9, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26888425

RESUMO

AIM: The ALK inhibitor, crizotinib, has demonstrated effectiveness in patients with non-small-cell lung cancer harboring ALK rearrangements. As few studies of the clinical characteristics of Chinese patients with ALK rearrangements have been reported, we conduct this study to gain more understanding in such area among Chinese patients. PATIENTS & METHODS: We undertook a retrospective study of 288 non-small-cell lung cancer patients admitted to our institution over a period of 4.5 years. RESULTS: Following testing, 14.9% of the patients (43/288) were found to be ALK fusion gene positive. Patient data including gender, age, smoking status, EGFR mutation status and medical imaging data were collected and analyzed. CONCLUSION: The findings suggested that patients with ALK rearrangements are more likely to be young, have EGFR wild-type, and more likely to exhibit mucus secretion, solid tumor growth, lymph node metastasis and pleural metastasis.


Assuntos
Povo Asiático/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/patologia , Receptores Proteína Tirosina Quinases/genética , Adulto , Idoso , Quinase do Linfoma Anaplásico , Carcinoma Pulmonar de Células não Pequenas/genética , Feminino , Rearranjo Gênico , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Neoplasias Pulmonares/genética , Masculino , Pessoa de Meia-Idade , Proteínas de Fusão Oncogênica/genética , Reação em Cadeia da Polimerase , Estudos Retrospectivos , Adulto Jovem
6.
Int J Clin Exp Pathol ; 8(3): 2392-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26045746

RESUMO

microRNA (mir)-365 exerts tumor suppressor function by targeting thyroid transcription factor-1 (TTF-1) in lung cancer cells. The purpose of the present study was to assess mir-365 and its target mRNA TTF-1 in lung cancer and their correlations with patients' survival. Quantitative real-time PCR was used to examine the expression levels of mir-365 and TTF-1 in tumor tissue and its adjacent noncancerous tissue of 126 patients with non-small cell lung cancer (NSCLC). Our results showed that mir-365 was significantly decreased in tumor tissue than that in normal tissue (P=0.006), however, TTF-1 was significantly increased in tumor tissue than in normal tissue (P<0.001). Besides, significant correlations between decreased mir-365 and advanced tumor-node-metastasis (TNM) stage (P=0.001) and regional lymph node involvement (P=0.037) was observed. The similar result was also found between increased TTF-1 and TNM stage (P=0.003). Furthermore, mir-365 downregulation or TTF-1 upregulation were associated with poor outcome of patients than mir-365 upregulation or TTF-1 downregulation (for mir-365: P<0.001; for TTF-1: P=0.002). Of note, combination of decreased mir-365 and increased TTF-1 had worst overall survival (P<0.001). In conclusion, aberrant expression of mir-365/TTF-1 may be involved in the tumor development in patients with NSCLC. Moreover, mir-365 and TTF-1 could jointly predict the prognosis of patients and their combination may serve as a biomarker to predict risk of poor survival in NSCLC patients. Mir-365/TTF-1 might serve as a potential therapeutic target for clinical treatment of NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/genética , MicroRNAs/genética , Proteínas Nucleares/genética , RNA Mensageiro/genética , Fatores de Transcrição/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/secundário , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Metástase Linfática , Masculino , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Proteínas Nucleares/metabolismo , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Risco , Fator Nuclear 1 de Tireoide , Fatores de Transcrição/metabolismo
7.
BMC Pregnancy Childbirth ; 15: 35, 2015 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-25884766

RESUMO

BACKGROUND: Preterm premature rupture of membranes (PPROM) is responsible for one third of all preterm births (PTBs). We have recently demonstrated that long noncoding RNAs (lncRNAs) are differentially expressed in human placentas derived from PPROM, PTB, premature rupture of the membranes (PROM), and full-term birth (FTB), and determined the major biological pathways involved in PPROM. METHODS: Here, we further investigated the relationship of lncRNAs, which are differentially expressed in spontaneous PTB (sPTB) and PPROM placentas and are found to overlap a coding locus, with the differential expression of transcribed mRNAs at the same locus. Ten lncRNAs (five up-regulated and five down-regulated) and the lncRNA-associated 10 mRNAs (six up- and four down-regulated), which were identified by microarray in comparing PPROM vs. sPTB, were then validated by real-time quantitative PCR. RESULTS: A total of 62 (38 up- and 24 down-regulated) and 1,923 (790 up- and 1,133 down-regulated) lncRNAs were identified from placentas of premature labor (sPTB + PPROM), as compared to those from full-term labor (FTB + PROM) and from premature rupture of membranes (PPROM + PROM), as compared to those from non-rupture of membranes (sPTB + FTB), respectively. We found that a correlation existed between differentially expressed lncRNAs and their associated mRNAs, which could be grouped into four categories based on the gene strand (sense or antisense) of lncRNA and its paired transcript. These findings suggest that lncRNA regulates mRNA transcription through differential mechanisms. Differential expression of the transcripts PPP2R5C, STAM, TACC2, EML4, PAM, PDE4B, STAM, PPP2R5C, PDE4B, and EGFR indicated a co-expression among these mRNAs, which are involved in the ubiquitine-proteasome system (UPS), in addition to signaling transduction and beta adrenergic signaling, suggesting that imbalanced regulation of UPS may present an additional mechanism underlying the premature rupture of membrane in PPROM. CONCLUSION: Differentially expressed lncRNAs that were identified from the human placentas of sPTB and PPROM may regulate their associated mRNAs through differential mechanisms and connect the ubiquitin-proteasome system with infection-inflammation pathways. Although the detailed mechanisms by which lncRNAs regulate their associated mRNAs in sPTB and PPROM are yet to be clarified, our findings open a new approach to explore the pathogenesis of sPTB and PPROM.


Assuntos
Ruptura Prematura de Membranas Fetais , Complexo de Endopeptidases do Proteassoma , RNA Longo não Codificante , Ubiquitina , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas de Transporte/genética , Regulação para Baixo , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Epigênese Genética , Feminino , Ruptura Prematura de Membranas Fetais/genética , Ruptura Prematura de Membranas Fetais/patologia , Humanos , Recém-Nascido , Masculino , Fosfoproteínas/genética , Placenta/patologia , Gravidez , Nascimento Prematuro/genética , Complexo de Endopeptidases do Proteassoma/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteína Fosfatase 2/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Transdução de Sinais/genética , Proteínas Supressoras de Tumor/genética , Ubiquitina/genética , Ubiquitina/metabolismo , Regulação para Cima
8.
J Mol Neurosci ; 56(1): 89-101, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25464930

RESUMO

Autism is a neurodevelopmental disorder with a strong genetic predisposition. Neurolign 3 (NLGN3) as a postsynaptic transmembrane protein, functions in both neuron synaptogenesis and glia-neuron communications. Previously, a gain of function mutation (R451C) in NLGN3 was identified in autistic patients, which illustrates the involvement of NLGN3 in autism pathogenesis. As proper synaptic targeting and functioning are controlled by intracellular protein interactions, in the current study, we tried to discover the intracellular regulation network in which NLGN3 might be involved by a yeast two-hybrid-based interactor identification. Fifty-one protein candidate partners were identified after screening a human fetal complementary DNA (cDNA) library with an intracellular fragment of NLGN3. The interactions of NLGN3 with a subset of candidates, including EEF1A1, FLNA, ITPRIP, CYP11A1, MT-CO2, GPR175, ACOT2, and QPRT, were further validated in human neuroblastoma cells or brain tissues. Furthermore, our study suggested that NLGN3 was functioning in cytosolic calcium balance and participating in calcium-regulated cellular processes. Our findings of novel NLGN3 binding partners provide evidences of involvement of NLGN3 in multiple biological pathways, especially calcium regulating and mitochondrial function, thus suggesting further significance. This new data not only leads to a better understanding of the physiological functions of NLGN3, but also provide new aspects for pathogenesis of autism.


Assuntos
Transtorno Autístico/metabolismo , Moléculas de Adesão Celular Neuronais/metabolismo , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Sequência de Aminoácidos , Cálcio/metabolismo , Linhagem Celular Tumoral , Humanos , Dados de Sequência Molecular , Neurônios/metabolismo , Ligação Proteica , Técnicas do Sistema de Duplo-Híbrido
9.
BMC Pregnancy Childbirth ; 14: 360, 2014 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-25366578

RESUMO

BACKGROUND: Preconception care is defined as the promotion of the health and well-being of a woman and her partner before pregnancy. Improving preconception health can result in improved reproductive health outcomes. China has issued latest version official guideline for preconception care in 2011. The objective of this cross-sectional study is to determine whether there is a variation in the quality of preconception healthcare services in distinct eastern and northern populations of China, and what factors are associated with such variation. METHODS: A cross-sectional survey using our previously developed preconception instrument was conducted. Women at reproductive age planning for pregnancy were surveyed along with their partners at hospitals during their pre-pregnancy health examination. Data collected include general health/life profiles, pregnancy history, alcohol/tobacco/drug exposures, immunizations, micronutrient supplements and the demands in preconception care. After quality assessment, statistical analysis were applied to evaluate the variations in preconception factors between people from Hebei and Jiangsu Provinces. RESULTS: 3202 women of reproductive age in from eastern province, Jiangsu, and in a northern province, Hebei, participated this study. 2806 of them and their partners have completed the questionnaire, at a rate of 87.6%, 1011 were from Jiangsu and 1795 were from Hebei. Statistical significance was obtained for maternal age (P < 0.001), body mass index (u =13.590, P <0.001), education (χ2 = 916.33, P < 0.001), occupation (χ2 = 901.78, P < 0.001), health status/common disease, immunization status, and need for preconception care. CONCLUSIONS: For a country as large as China, the centralized guideline for standardized preconception healthcare does have a very crucial positive role in reproductive healthcare, but it may not be suited for all populations. Regional authorities should consider the demographics and healthcare needs of the local population and modify the centralized guideline accordingly, as well as provide a better education and professional services for the public, to improve the quality of preconception services at both the regional and the national level.


Assuntos
Necessidades e Demandas de Serviços de Saúde , Saúde do Homem , Cuidado Pré-Concepcional/normas , Serviços de Saúde Reprodutiva/organização & administração , Saúde da Mulher , China , Estudos Transversais , Atenção à Saúde/normas , Serviços de Planejamento Familiar/organização & administração , Feminino , Guias como Assunto , Humanos , Estilo de Vida , Masculino , Gravidez , Cuidado Pré-Natal/normas , Inquéritos e Questionários
10.
Brain Res ; 1444: 76-86, 2012 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-22330724

RESUMO

This study aimed to investigate the effects of SDF-1α on brain angiogenesis and neurological functional recovery in rats after traumatic brain injury (TBI) and the potentially involved mechanisms. Youth male Wistar rats were injured via lateral fluid percussion injury and then randomly divided into one of 3 groups: I. vehicle treated group; II. SDF-1α neutralizing antibody treated group and III. rhSDF-1α treated group. rhSDF-1α and its neutralizing antibody or normal saline were administered to the brain penumbra via stereotactic injection 30min after TBI. Modified neurological severity score (mNSS) and Morris water maze (MWM) test were used to assess the neurologic functional recovery (n=6/group). 14days after injury, animals were euthanized and brain tissues were collected for quantitative real time polymerase chain reaction (qRT-PCR) (n=6/group) and immunohistochemistry (n=6/group) analysis. mNSS and MWM test indicated distinct amelioration of neurological disability in rhSDF-1α group(P<0.05). Microvessel density (MVD) of rhSDF-1α treated animals was remarkably increased around the injured area. On the contrary, MVD of the SDF-1α antibody administrated group was significantly decreased compared to that of vehicle treated animals (P<0.05). The mNSS and MVD had significant negative correlation as tested by Spearman rank correlation coefficient. Immunofluorescence staining showed that CD34 and CXCR4 co-expressed on microvessels. The rhSDF-1α treated animals had greater, contrarily, the SDF-1α antibody treated animals had lesser number of double positive microvessels compared to that of vehicle treated animals. The mRNA expression of CD34 and CXCR4 was obviously elevated in the rhSDF-1α administration group, conversely, declined in SDF-1α antibody treated animals around the injured area compared with that of the vehicle treatment group (P<0.05). These data indicated that SDF-1α could induce angiogenesis after TBI, potentially via SDF-1/CXCR4 axis.


Assuntos
Indutores da Angiogênese/uso terapêutico , Lesões Encefálicas/tratamento farmacológico , Quimiocina CXCL12/uso terapêutico , Regulação da Expressão Gênica/efeitos dos fármacos , Análise de Variância , Animais , Anticorpos/administração & dosagem , Antígenos CD34/metabolismo , Lesões Encefálicas/complicações , Lesões Encefálicas/patologia , Quimiocina CXCL12/imunologia , Quimiocina CXCL12/metabolismo , Modelos Animais de Doenças , Humanos , Deficiências da Aprendizagem/tratamento farmacológico , Deficiências da Aprendizagem/etiologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Microvasos/efeitos dos fármacos , Microvasos/patologia , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Tempo de Reação/efeitos dos fármacos , Receptores CXCR4/genética , Receptores CXCR4/metabolismo , Fatores de Tempo , Índices de Gravidade do Trauma
11.
J Bacteriol ; 193(9): 2236-41, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21378185

RESUMO

DEAD-box proteins (DBPs) are a widespread class of ATP-dependent RNA helicases that play a key role in unwinding RNA duplexes. In recent years, certain DBPs have also been found to exhibit activities that do not require ATP. To gain a better understanding of prokaryotic RNA metabolism, we investigated whether Escherichia coli DBPs harbor any ATP-independent activities. We show that each of the four E. coli DBPs tested in this study can accelerate the association of cRNA molecules, can stimulate strand displacement, and can function as an RNA chaperone without utilizing ATP. To the best of our knowledge, these prokaryotic DBPs constitute the first examples of proteins that harbor each of these three activities. The identification of these auxiliary functions indicates that the E. coli DBPs are versatile factors that possess significant RNA remodeling activity in addition to their canonical RNA helicase activity and might therefore participate in a greater variety of cellular processes than has been previously appreciated.


Assuntos
Trifosfato de Adenosina/metabolismo , RNA Helicases DEAD-box/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/enzimologia , RNA Helicases DEAD-box/genética , Reparo do DNA , DNA Bacteriano , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica/fisiologia , Chaperonas Moleculares , RNA Bacteriano
12.
Biochim Biophys Acta ; 1804(10): 1954-64, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20624489

RESUMO

PCBP1 is a member of the hnRNP family and participates in the regulation of transcription and translation. Previously, we identified transcripts targeted by overexpression of exogenous PCBP1. To further determine if these altered transcripts may also be targeted by a lack of PCBP1, we depleted endogenous PCBP1 in human SH-SY5Y cells. We identified 941 transcripts with the Affymetrix and 1362 with the Agilent expression platforms. There were 375 transcripts identified by both platforms, including 328 down-regulated and 47 up-regulated. The identified transcripts could be grouped into neuronal, cell signaling, metabolic, developmental, and differentiation categories, with pathway involvement in Wnt signaling, TGF beta signaling, translation factors and nuclear receptors. A proteomic profiling study with a two-dimensional chromatographic platform showed global translational changes over a range of isoelectric points (pI)=4.84-8.42. This study identifies the transcripts affected by knock-down of endogenous PCBP1 and compares them to the transcripts affected by overexpression of PCBP1.


Assuntos
Biomarcadores Tumorais/genética , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Ribonucleoproteínas Nucleares Heterogêneas/genética , Neuroblastoma/genética , Biomarcadores Tumorais/metabolismo , Western Blotting , Proteínas de Ligação a DNA , Eletroforese em Gel Bidimensional , Ribonucleoproteínas Nucleares Heterogêneas/antagonistas & inibidores , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Humanos , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/genética , RNA Interferente Pequeno/farmacologia , Proteínas de Ligação a RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Células Tumorais Cultivadas
13.
Mol Cell Biol ; 30(17): 4108-19, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20606010

RESUMO

The polypyrimidine tract near the 3' splice site is important for pre-mRNA splicing. Using pseudouridine incorporation and in vivo RNA-guided RNA pseudouridylation, we have identified two important uridines in the polypyrimidine tract of adenovirus pre-mRNA. Conversion of either uridine into pseudouridine leads to a splicing defect in Xenopus oocytes. Using a variety of molecular biology methodologies, we show that the splicing defect is due to the failure of U2AF(65) to recognize the pseudouridylated polypyrimidine tract. This negative impact on splicing is pseudouridine specific, as no effect is observed when the uridine is changed to other naturally occurring nucleotides. Given that pseudouridine favors a C-3'-endo structure, our results suggest that it is backbone flexibility that is key to U2AF binding. Indeed, locking the key uridine in the C-3'-endo configuration while maintaining its uridine identity blocks U2AF(65) binding and splicing. This pseudouridine effect can also be applied to other pre-mRNA polypyrimidine tracts. Thus, our work demonstrates that in vivo binding of U2AF(65) to a polypyrimidine tract requires a flexible RNA backbone.


Assuntos
Proteínas Nucleares/metabolismo , Pirimidinas/metabolismo , Precursores de RNA/metabolismo , Splicing de RNA , Ribonucleoproteínas/metabolismo , Animais , Sequência de Bases , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Oócitos/metabolismo , Ligação Proteica , Pirimidinas/química , Precursores de RNA/química , Fator de Processamento U2AF , Uridina/química , Uridina/metabolismo , Xenopus
14.
Beijing Da Xue Xue Bao Yi Xue Ban ; 41(4): 414-7, 2009 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-19727230

RESUMO

OBJECTIVE: To investigate the birth defect condition in Haidian district of Beijing city, 61,272 live-born infants who were delivered in Haidian Maternal and Child Health Hospital from 2003 to the March of 2009 are analyzed. METHODS: Data was collected from the hospital's medical records and from the birth defect surveillance. RESULTS: Among the newborns studied, 1 076 were found having birth defect (17.56 per thousand). The most common birth defects are congenital heart defect, followed by dysmorphosis of external ear, polydactyly, hypospadia, cleft lip and palate. In addition, three birth defects that are not included in the birth defect surveillance list were enorchia, renal agenesis and giant hemangioma. The birth defect rates of preterm and small for gestational age infants are significantly higher than it of the term infants. The birth defect patterns for these two types of abnormal infants are distinct. CONCLUSION: We have determined the pattern of birth defects in Beijing, which may help in policy-making regarding the prevention and intervention of birth defects.


Assuntos
Anormalidades Congênitas/epidemiologia , Orelha Externa/anormalidades , Cardiopatias Congênitas/epidemiologia , China/epidemiologia , Feminino , Dedos/anormalidades , Humanos , Recém-Nascido , Masculino , Polidactilia/epidemiologia , Prevalência
15.
Nat Methods ; 5(1): 95-100, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18066073

RESUMO

Most eukaryotic box C/D small nucleolar (sno) or Cajal body-specific RNAs guide base pairing with target RNAs and direct site-specific 2'-O-methylation. We designed an artificial C/D RNA to target the branch point adenosine of ACT1 pre-mRNA to block its splicing. Saccharomyces cerevisiae expressing this guide RNA gene controlled by a GAL1 promoter grew normally on dextrose but not on galactose medium. The pre-mRNA was specifically 2'-O-methylated, prohibiting maturation of ACT1 mRNA. Targeting other adenosines in this region while maintaining almost identical complementarity did not affect ACT1 mRNA level or cell growth, suggesting that targeting the branch-point adenosine was truly 2'-O-methylation-specific rather than an antisense effect; moreover, only the 3'-most branch site adenosine served as the branch point. We targeted other essential intron-containing genes, and observed a similar phenotype. We demonstrated that a Box C/D RNA can guide modification at the pre-mRNA branch point, thus silencing its expression and inducing cell death.


Assuntos
Regulação Fúngica da Expressão Gênica/genética , Inativação Gênica/fisiologia , Marcação de Genes/métodos , RNA Mensageiro/genética , Saccharomyces cerevisiae/genética , Regiões Promotoras Genéticas/genética
16.
Nucleic Acids Res ; 35(2): 550-8, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17169984

RESUMO

5-fluorouracil (5FU) is an effective anti-cancer drug, yet its mechanism of action remains unclear. Here, we examine the effect of 5FU on pre-mRNA splicing in vivo. Using RT-PCR, we show that the splicing of a number of pre-mRNAs is inhibited in HeLa cells that have been exposed to a low dose of 5FU. It appears that this inhibitory effect is not due to its incorporation into pre-mRNA, because partially or fully 5FU-substituted pre-mRNA, when injected into Xenopus oocytes, is spliced just as well as is the unsubstituted pre-mRNA. Detailed analyses of 5FU-treated cells indicate that 5FU is incorporated into U2 snRNA at important naturally occurring pseudouridylation sites. Remarkably, 5FU incorporation effectively blocks the formation of important pseudouridines in U2 snRNA, as only a trace of pseudouridine is detected when cells are exposed to a low dose of 5FU for 5 days. Injection of the hypopseudouridylated HeLa U2 snRNA into U2-depleted Xenopus oocytes fails to reconstitute pre-mRNA splicing, whereas control U2 isolated from untreated or uracil-treated HeLa cells completely reconstitutes the splicing. Our results demonstrate for the first time that 5FU incorporates into a spliceosomal snRNA at natural pseudouridylation sites in vivo, thereby inhibiting snRNA pseudouridylation and splicing. This mechanism may contribute substantially to 5FU-mediated cell death.


Assuntos
Antimetabólitos Antineoplásicos/metabolismo , Antimetabólitos Antineoplásicos/farmacologia , Fluoruracila/metabolismo , Fluoruracila/farmacologia , Pseudouridina/metabolismo , Splicing de RNA/efeitos dos fármacos , RNA Nuclear Pequeno/antagonistas & inibidores , Animais , Sequência de Bases , Células HeLa , Humanos , Dados de Sequência Molecular , Oócitos/metabolismo , Precursores de RNA/metabolismo , RNA Mensageiro/metabolismo , RNA Nuclear Pequeno/química , RNA Nuclear Pequeno/metabolismo , Xenopus
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