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1.
Am J Med Genet A ; 185(2): 384-389, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33166031

RESUMO

Schuurs-Hoeijmakers syndrome (SHS) is a rare syndrome involving a de novo variant in the PACS1 gene on chromosome 11q13. There are 36 individuals published in the literature so far, mostly diagnosed postnatally (34/36) after recognizing the typical facial features co-occurring with developmental delay, intellectual disability, and multiple malformations. Herein, we present one prenatal and 15 postnatal cases with the recurrent heterozygous pathogenic variant NM_018026.3:c.607C>T p.(Arg203Trp) in the PACS1 gene detected by exome sequencing. These 16 cases were identified by mining Centogene and the Hong Kong clinical genetic service databases. Collectively, the 49 postnatally diagnosed individuals present with typical facial features and developmental delay, while the three prenatally diagnosed individuals present with multiple congenital anomalies. In the current study, the use of exome sequencing as an unbiased diagnostic tool aided the diagnosis of SHS (pre- and postnatally). The identification of additional cases with SHS add to the current understanding of the clinical phenotype associated with pathogenic PACS1 variants. Databases combining clinical and genetic information are helpful for the study of rare diseases.


Assuntos
Anormalidades Múltiplas/genética , Deficiências do Desenvolvimento/genética , Deficiência Intelectual/genética , Proteínas de Transporte Vesicular/genética , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/patologia , Criança , Deficiências do Desenvolvimento/diagnóstico , Deficiências do Desenvolvimento/patologia , Feminino , Heterozigoto , Humanos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/patologia , Masculino , Fenótipo , Diagnóstico Pré-Natal/métodos , Sequenciamento do Exoma
2.
BMC Pregnancy Childbirth ; 20(1): 109, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32059709

RESUMO

BACKGROUND: Chromosomal microarray (CMA) has been shown to be cost-effective over karyotyping in invasive prenatal diagnosis for pregnancies with fetal ultrasound anomalies. Yet, information regarding preceding and subsequent tests must be considered as a whole before the true cost-effectiveness can emerge. Currently in Hong Kong, karyotyping is offered free as the standard prenatal test while genome-wide array comparative genome hybridization (aCGH), a form of CMA, is self-financed. A new algorithm was proposed to use aCGH following quantitative fluorescent polymerase chain reaction (QF-PCR) as primary test instead of karyotyping. This study aims to evaluate the cost-effectiveness of the proposed algorithm versus the current algorithm for prenatal diagnosis in Hong Kong. METHODS: Between November 2014 and February 2016, 129 pregnant women who required invasive prenatal diagnosis at two public hospitals in Hong Kong were prospectively recruited. The proposed algorithm was performed for all participants in this demonstration study. For the cost-effectiveness analysis, cost and outcome (diagnostic rate) data were compared with that of a hypothetical scenario representing the current algorithm. Further analysis was performed to incorporate women's willingness-to-pay for the aCGH test. Impact of government subsidies on the aCGH test was explored as a sensitivity analysis. RESULTS: The proposed algorithm dominated the current algorithm for prenatal diagnosis. Both algorithms were equally effective but the proposed algorithm was significantly cheaper (p ≤ 0.05). Taking into account women's willingness-to-pay for an aCGH test, the proposed algorithm was more effective and less costly than the current algorithm. When the government subsidy reaches 100%, the maximum number of diagnoses could be made. CONCLUSION: By switching to the proposed algorithm, cost saving can be achieved whilst maximizing the diagnostic rate for invasive prenatal diagnosis. It is recommended to implement aCGH as a primary test following QF-PCR to replace the majority of karyotyping for prenatal diagnosis in Hong Kong.


Assuntos
Hibridização Genômica Comparativa/economia , Análise Custo-Benefício , Cariotipagem/economia , Diagnóstico Pré-Natal/métodos , Algoritmos , Aneuploidia , Feminino , Hong Kong , Humanos , Reação em Cadeia da Polimerase , Gravidez , Saúde Pública
3.
Angew Chem Int Ed Engl ; 59(26): 10327-10331, 2020 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-32163217

RESUMO

The chromosome periphery (CP) is a complex network that covers the outer surface of chromosomes. It acts as a carrier of nucleolar components, helps maintain chromosome structure, and plays an important role in mitosis. Current methods for fluorescence imaging of CP largely rely on immunostaining. We herein report a small-molecule fluorescent probe, ID-IQ, which possesses aggregation-induced emission (AIE) property, for CP imaging. By labelling the CP, ID-IQ sharply highlighted the chromosome boundaries, which enabled rapid segmentation of touching and overlapping chromosomes, direct identification of the centromere, and clear visualization of chromosome morphology. ID-IQ staining was also compatible with fluorescence in situ hybridization and could assist the precise location of the gene in designated chromosome. Altogether, this study provides a versatile cytogenetic tool for improved chromosome analysis, which greatly benefits the clinical diagnostic testing and genomic research.


Assuntos
Cromossomos/metabolismo , Análise Citogenética/métodos , Corantes Fluorescentes/química , Carbolinas/química , Linhagem Celular Tumoral , Centrômero/metabolismo , Cromossomos/ultraestrutura , Humanos , Hibridização in Situ Fluorescente , Células-Tronco Pluripotentes Induzidas , Linfócitos , Microscopia Confocal , Microscopia de Fluorescência
4.
J Med Genet ; 55(12): 847-852, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30007940

RESUMO

BACKGROUND: We report here clinical, cytogenetic and molecular data for a pair of monochorionic diamniotic twins with paternal isodisomy for chromosome 19. Both twins presented with dysmorphic features and global developmental delay. This represents, to our knowledge, the first individual human case of paternal uniparental disomy for chromosome 19 (UPD19). METHODS: Whole-exome sequencing, together with conventional karyotype and SNP array analysis were performed along with genome-wide DNA methylation array for delineation of the underlying molecular defects. RESULTS: Conventional karyotyping on amniocytes and lymphocytes showed normal karyotypes for both twins. Whole-exome sequencing did not identify any pathogenic sequence variants but >5000 homozygous exonic variants on chromosome 19, suggestive of UPD19. SNP arrays on blood and buccal DNA both showed paternal isodisomy for chromosome 19. Losses of imprinting for known imprinted genes on chromosome 19 were identified, including ZNF331, PEG3, ZIM2 and MIMT1. In addition, imprinting defects were also identified in genes located on other chromosomes, including GPR1-AS, JAKMP1 and NHP2L1. CONCLUSION: Imprinting defects are the most likely cause for the dysmorphism and developmental delay in this first report of monozygotic twins with UPD19. However, epigenotype-phenotype correlation will require identification of additional individuals with UPD19 and further molecular analysis.


Assuntos
Transtornos Cromossômicos/diagnóstico , Transtornos Cromossômicos/genética , Cromossomos Humanos Par 19 , Deficiências do Desenvolvimento/diagnóstico , Deficiências do Desenvolvimento/genética , Gêmeos Monozigóticos , Dissomia Uniparental , Alelos , Análise Mutacional de DNA , Fácies , Feminino , Humanos , Recém-Nascido , Cariotipagem , Mutação , Herança Paterna , Fenótipo , Diagnóstico Pré-Natal , Sequenciamento do Exoma
6.
Diagnostics (Basel) ; 14(1)2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38201411

RESUMO

Fetal hyperthyroidism can occur secondary to maternal autoimmune hyperthyroidism. The thyroid-stimulating hormone receptor antibody (TRAb) transferred from the mother to the fetus stimulates the fetal thyroid and causes fetal thyrotoxicosis. Fetuses with this condition are difficult to detect, especially after maternal Graves disease therapy. Here, we present two cases of fetal hyperthyroidism with maternal hypothyroidism and review the assessment and intrauterine therapy for fetal hyperthyroidism. Both women were referred at 22+ and 23+ weeks of gestation with abnormal ultrasound findings, including fetal heart enlargement, pericardial effusion, and fetal tachycardia. Both women had a history of Graves disease while in a state of hypothyroidism with a high titer of TRAb. A sonographic examination showed a diffusely enlarged fetal thyroid with abundant blood flow. Invasive prenatal testing revealed no significant chromosomal aberration. Low fetal serum TSH and high TRAb levels were detected in the cord blood. Fetal hyperthyroidism was considered, and maternal oral methimazole (MMI) was administered as intrauterine therapy, with the slowing of fetal tachycardia, a reduction in fetal heart enlargement, and thyroid hyperemia. During therapy, maternal thyroid function was monitored, and the dosage of maternal levothyroxine was adjusted accordingly. Both women delivered spontaneously at 36+ weeks of gestation, and neonatal hyperthyroidism was confirmed in both newborns. After methimazole and propranolol drug treatment with levothyroxine for 8 and 12 months, both babies became euthyroid with normal growth and development.

7.
Cancer Lett ; 576: 216401, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37774827

RESUMO

This scientometric study aimed to provide a first comprehensive overview of the global research landscape of Metronomic Chemotherapy (MC) from 2000 to 2022 using a data-driven approach to identify key trends, collaborations, and potential opportunities. This study highlights the increasing prevalence of MC, with annual outputs increasing substantially over the same timeframe. The United States contributed the most to MC research, followed by Italy and China, while there was a lack of collaborative research efforts between countries and organizations. Through keyword co-occurrence analysis, we identified emerging interdisciplinary research areas, such as "nanoparticles," "immunotherapy," and "antitumor immunity." Our citation analysis identified the most influential authors, institutions, and journals, providing a comprehensive overview of the structure of knowledge and dissemination of MC research. Although the number of publications has decreased since 2019, the analysis indicates that this field has received substantial scholarly attention. These discoveries are extremely important for researchers, funding organizations, and policymakers because they highlight the need for more collaboration, interdisciplinary approaches, and resource allocation in underrepresented fields. This study concludes with recommendations for guiding future research and collaboration, resulting in a larger impact and fostering substantial advancements in MC research.

8.
Am J Pathol ; 179(2): 992-1003, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21689625

RESUMO

The transcription factors Pea3, Erm, and Er81 can promote cancer initiation and progression in various types of solid tumors. However, their role in esophageal squamous cell carcinoma (ESCC) has not been elucidated. In this study, we found that the expression levels of Pea3 and Erm, but not that of Er81, were significantly higher in ESCC compared with nontumor esophageal epithelium. A high level of Pea3 expression was significantly correlated with a shorter overall survival in a cohort of 81 patients with ESCC and the subgroup with N1 stage tumor (Wilcoxon-Gehan test, P = 0.016 and P = 0.001, respectively). Pea3 was overexpressed in seven ESCC cell lines compared with two immortalized esophageal cell lines. Pea3 knockdown reduced cell proliferation and suppressed nonadherent growth, migration, and invasion in ESCC cells in vitro. In addition, Pea3 knockdown in ESCC cells resulted in a down-regulation of phospho-Akt and matrix metalloproteinase 13, whereas a significant positive correlation in the expression levels was observed between Pea3 and phospho-Akt (r = 0.281, P < 0.013) and between Pea3 and matrix metalloproteinase 13 in the human specimens (r = 0.462, P < 0.001). Moreover, Pea3 modulated the sensitivity of EC109 cells to doxorubicin, probably via reduced activity of the phosphatidylinositol 3-kinase-Akt-mammalian target of Rapamycin complex 1 pathway on Pea3 knockdown. In conclusion, our results suggest that Pea3 plays an important role in the progression of ESCC.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Neoplasias Esofágicas/metabolismo , Regulação Neoplásica da Expressão Gênica , Fatores de Transcrição/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Movimento Celular , Proteínas de Ligação a DNA/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Fatores de Transcrição/metabolismo
10.
Healthcare (Basel) ; 10(12)2022 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-36554045

RESUMO

Fetal structural congenital abnormalities (SCAs) complicate 2-3% of all pregnancies. Whole-exome sequencing (WES) has been increasingly adopted prenatally when karyotyping and chromosomal microarray do not yield a diagnosis. This is a retrospective cohort study of 104 fetuses with SCAs identified on antenatal ultrasound in Hong Kong, where whole exome sequencing is performed. Molecular diagnosis was obtained in 25 of the 104 fetuses (24%). The highest diagnostic rate was found in fetuses with multiple SCAs (29.2%), particularly those with involvement of the cardiac and musculoskeletal systems. Variants of uncertain significance were detected in 8 out of the 104 fetuses (7.7%). Our study shows the utility of WES in the prenatal setting, and the extended use of the technology would be recommended in addition to conventional genetic workup.

11.
NPJ Genom Med ; 7(1): 23, 2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35314707

RESUMO

Traditional carrier screening has been utilized for the detection of carriers of genetic disorders. Since a comprehensive assessment of the carrier frequencies of recessive conditions in the Southern Chinese population is not yet available, we performed a secondary analysis on the spectrum and carrier status for 315 genes causing autosomal recessive disorders in 1543 Southern Chinese individuals with next-generation sequencing data, 1116 with exome sequencing and 427 with genome sequencing data. Our data revealed that 1 in 2 people (47.8% of the population) was a carrier for one or more recessive conditions, and 1 in 12 individuals (8.30% of the population) was a carrier for treatable inherited conditions. In alignment with current American College of Obstetricians and Gynecologists (ACOG) pan-ethnic carrier recommendations, 1 in 26 individuals were identified as carriers of cystic fibrosis, thalassemia, and spinal muscular atrophy in the Southern Chinese population. When the >1% expanded carrier screening rate recommendation by ACOG was used, 11 diseases were found to meet the criteria in the Southern Chinese population. Approximately 1 in 3 individuals (35.5% of the population) were carriers of these 11 conditions. If the 1 in 200 carrier frequency threshold is used, and additional seven genes would meet the criteria, and 2 in 5 individuals (38.7% of the population) would be detected as a carrier. This study provides a comprehensive catalogue of the carrier spectrum and frequency in the Southern Chinese population and can serve as a reference for careful evaluation of the conditions to be included in expanded carrier screening for Southern Chinese people.

12.
J Infect Dis ; 201(12): 1899-908, 2010 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-20462354

RESUMO

Myxovirus resistance A (MxA) is an antiviral protein induced by interferon alpha and beta (IFN-alpha, IFN-beta) that can inhibit viral replication. The minor alleles of the -88G>T and -123C>A MxA promoter single-nucleotide polymorphisms (SNPs) are associated with increased promoter activity and altered response to IFN-alpha and IFN-beta treatment. Here, we demonstrate that the -123A minor allele provided stronger binding affinity to nuclear proteins extracted from IFN-beta-untreated cells than did the wild-type allele, whereas the -88T allele showed preferential binding after IFN-beta stimulation. Endogenous IFN-alpha and IFN-beta induction can be suppressed in severe acute respiratory syndrome (SARS) coronavirus infection. In support of our in vitro findings, a large case-control genetic-association study for SARS coronavirus infection confirmed that the -123A minor-allele carriers were significantly associated with lower risk of SARS coronavirus infection, whereas the -88T minor-allele carriers were insignificant after adjustment for confounding effects. This suggests that -123C>A plays a more important role in modulating basal MxA expression, thus contributing more significantly to innate immune response against viral infections that suppress endogenous IFN-alpha and IFN-beta induction such as SARS coronavirus.


Assuntos
Proteínas de Ligação ao GTP/genética , Proteínas de Ligação ao GTP/imunologia , Interferon beta/imunologia , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Síndrome Respiratória Aguda Grave/genética , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Imunidade Inata , Interferon-alfa/imunologia , Masculino , Pessoa de Meia-Idade , Proteínas de Resistência a Myxovirus , Síndrome Respiratória Aguda Grave/imunologia , Adulto Jovem
13.
Clin Case Rep ; 8(8): 1369-1375, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32884756

RESUMO

Mosaic variegated aneuploidy (MVA) is a rare genetic disorder caused by mutations in BUB1B, CEP57, or TRIP13. We describe the prenatal diagnosis, molecular characterization, and clinical management of a long-lived patient with BUB1B-related MVA.

14.
Front Genet ; 11: 620162, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33584815

RESUMO

Balanced chromosomal abnormalities (BCAs) are changes in the localization or orientation of a chromosomal segment without visible gain or loss of genetic material. BCAs occur at a frequency of 1 in 500 newborns and are associated with an increased risk of multiple congenital anomalies and/or neurodevelopmental disorders, especially if it is a de novo mutation. In this pilot project, we used short read genome sequencing (GS) to retrospectively re-sequence ten prenatal subjects with de novo BCAs and compared the performance of GS with the original karyotyping. GS characterized all BCAs found by conventional karyotyping with the added benefit of precise sub-band delineation. By identifying BCA breakpoints at the nucleotide level using GS, we found disruption of OMIM genes in three cases and identified cryptic gain/loss at the breakpoints in two cases. Of these five cases, four cases reached a definitive genetic diagnosis while the other one case had a BCA interpreted as unknown clinical significance. The additional information gained from GS can change the interpretation of the BCAs and has the potential to improve the genetic counseling and perinatal management by providing a more specific genetic diagnosis. This demonstrates the added clinical utility of using GS for the diagnosis of BCAs.

15.
Int J Pediatr Endocrinol ; 2020: 13, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32670376

RESUMO

BACKGROUND: Beckwith-Wiedemann syndrome (BWS) is an overgrowth syndrome with variable clinical phenotype and complex molecular aetiology. It is mainly caused by dysregulation of the chromosome 11p15 imprinted region, which results in overgrowth in multiple tissues, often in a mosaic manner. CASE PRESENTATION: A large-for-gestational-age infant without any other somatic features of BWS presented with medically refractory hyperinsulinism (HI) requiring 80% pancreatectomy. Next generation sequencing with congenital HI sequencing panel identified a pathogenic ABCC8:c.1792C > T (p.Arg598Ter) variant of paternal origin, suggestive of focal HI. However, pancreatic histology revealed atypical findings of coalescing nests and trabeculae of adenomatosis scattered with islets with isolated enlarged, hyperchromatic nuclei scattered throughout the pancreas. Methylation analysis, SNP-based chromosomal microarray and short tandem repeat markers analysis revealed mosaic segmental paternal uniparental disomy (UPD) 11p15.5-p15.1 in the pancreatic tissue, but not the peripheral blood, suggestive of BWS/BW-spectrum HI. CONCLUSIONS: This case highlights the importance of integrating the clinical presentation and subsequent clinical course, together with radiological, genetic and histological findings in the definitive diagnosis of this rare yet clinically important entity. In addition, this is the first report that demonstrated the level of paternal inherited c.1792 T pathogenic variant in the pancreatic tissue being directly correlated to the mosaic level of pUPD.

16.
Stem Cell Res ; 49: 102040, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33099108

RESUMO

We derived an integration-free induced pluripotent stem cell (iPSC) line from the peripheral blood mononuclear cells (PBMCs) of a 23-year-old male patient. This patient carries a 5' splice site point mutation in intron 1 (c.31+1G>A) of the dystrophin gene, a mutation associated with X-linked dilated cardiomyopathy (XLDCM). Sendai virus was used to reprogram the PBMCs and deliver OCT3/4, SOX2, c-MYC, and KLF4 factors. The iPSC line (HKUi002-A) generated preserved the mutation, expressed common pluripotency markers, differentiated into three germ layers in vivo, and exhibited a normal karyotype. Further differentiation into cardiomyocytes enables the study of the disease mechanisms of XLDCM.


Assuntos
Células-Tronco Pluripotentes Induzidas , Adulto , Cardiomiopatia Dilatada , Diferenciação Celular , Genômica , Humanos , Fator 4 Semelhante a Kruppel , Leucócitos Mononucleares , Masculino , Mutação , Miócitos Cardíacos , Adulto Jovem
17.
J Matern Fetal Neonatal Med ; 32(2): 348-350, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28927326

RESUMO

In this first Asian study, the decision outcomes (decision conflict, decision regret, and anxiety) of 262 pregnant women offered noninvasive prenatal test (NIPT) for high-risk Down screening results were assessed. Decision conflict was experienced by 3.5% and level of decisional regret low (mean score 15.7, 95%CI 13.2-18.3). All 13 cases of decisional regret were NIPT acceptors. Elevated anxiety was experienced by 55.9% at the time of decision making about NIPT and persistent in 30.3%. Insufficient knowledge about NIPT was associated with elevated anxiety at decision making (p = .011) and with decisional regret (p = .016). Decisional regret was associated with prolonged anxiety (p = .010).


Assuntos
Tomada de Decisões/fisiologia , Síndrome de Down/diagnóstico , Diagnóstico Pré-Natal/métodos , Diagnóstico Pré-Natal/psicologia , Aborto Induzido/psicologia , Aborto Induzido/estatística & dados numéricos , Adulto , Ansiedade/epidemiologia , Ansiedade/etiologia , Conflito Psicológico , Emoções , Feminino , Seguimentos , Humanos , Testes para Triagem do Soro Materno/métodos , Testes para Triagem do Soro Materno/psicologia , Gravidez , Inquéritos e Questionários
18.
Epilepsia Open ; 4(1): 63-72, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30868116

RESUMO

OBJECTIVE: Early onset drug-resistant epilepsy is a neurologic disorder in which 2 antiepileptic drugs fail to maintain the seizure-free status of the patient. Heterogeneous clinical presentations make the diagnosis challenging. We aim to identify the underlying genetic causes of a pediatric cohort with drug-resistant epilepsy and evaluate whether the findings can provide information on patient management. METHODS: We include patients with drug-resistant epilepsy onset before 18 years of age. Singleton clinical chromosomal microarray (CMA) followed by whole exome sequencing (WES) was performed using genomic DNA. In the first-tier analysis of the exome data, we aimed to identify disease-causing mutations in 546 genes known to cause, or to be associated with, epilepsy. For negative cases, we proceeded to exome-wide analysis. Rare coding variants were interrogated for pathogenicity based on the American College of Medical Genetics and Genomics (ACMG) guidelines. RESULTS: We recruited 50 patients. We identified 6 pathogenic or likely pathogenic mutations, giving a diagnostic yield of 12%. Mutations were found in 6 different genes: SCN8A, SCN1A, MECP2, CDKL5, DEPDC5, and CHD2. The CDKL5 variant was found to be mosaic. One variant of unknown significance (VUS) in KCNT1 was found in a patient with compatible clinical features. Of note, a reported pathogenic SCN5A mutation known to contribute to Brugada syndrome, was also found in the patient with an SCN1A mutation. SIGNIFICANCE: Our study suggests that singleton WES is an effective diagnostic tool for drug-resistant epilepsy. Genetic diagnosis can help to consolidate the clinical diagnosis, to facilitate phenotypic expansion, and to influence treatment and management options for seizure control in our patients. In our study, a significant portion of the genetic findings are known to be associated with an increased risk of sudden unexpected death in epilepsy (SUDEP). These findings could assist with more appropriate management in patients with epilepsy.

19.
Int J Cancer ; 123(2): 296-302, 2008 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-18404674

RESUMO

Epigenetic aberration is known to be important in human carcinogenesis. Promoter methylation status of RAS effector related genes, RASSF1A, RASSF2A, hDAB2IP (m2a and m2b regions) and BLU, was evaluated in 76 endometrial carcinomas and their non-neoplastic endometrial tissue by methylation specific PCR. Hypermethylation of at least one of the 5 genes was detected in 73.7% of carcinomas. There were significant correlations between methylation of hDAB2IP and RASSF1A, RASSF2A (p = 0.042, p = 0.012, respectively). Significantly, more frequent RASSF1A hypermethylation was found in Type I endometrioid carcinomas than Type II carcinomas (p = 0.049). Among endometrioid cancers, significant association between RASSF1A hypermethylation and advanced stage, as well as between methylation of hDAB2IP at m2a region with deep myometrial invasion (p < 0.05) was observed. mRNA expression of RASSF1A, RASSF2A and BLU in endometrial cancer cell lines significantly increased after treatment with the demethylating agent 5-Aza-2'-deoxycytidine supporting the repressive effect of hypermethylation on their transcription. Immunohistochemical study of DNMT1 on eight normal endometrium, 16 hyperplastic endometrium without atypia, 40 atypical complex hyperplasia and 79 endometrial carcinomas showed progressive increase in DNMT1 immunoreactivity from normal endometrium to endometrial hyperplasia and endometrioid carcinomas (p = 0.001). Among carcinomas, distinctly higher DNMT1 expression was observed in Type I endometrioid carcinomas (p < 0.001). DNMT1 immunoreactivity correlated with RASSF1A and RASSF2A methylation (p < 0.05). The data suggested that hypermethylation of RAS related genes, particularly RASSF1A, was involved in endometrial carcinogenesis with possible divergent patterns in different histological types. DNMT1 protein overexpression might contribute to such aberrant DNA hypermethylation of specific tumor suppressor genes in endometrial cancers.


Assuntos
Carcinoma Endometrioide/genética , Metilação de DNA , Neoplasias do Endométrio/genética , Genes ras , Proteínas Repressoras/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Endometrioide/enzimologia , Carcinoma Endometrioide/metabolismo , Carcinoma Endometrioide/patologia , Proteínas do Citoesqueleto , Primers do DNA , Neoplasias do Endométrio/enzimologia , Neoplasias do Endométrio/metabolismo , Neoplasias do Endométrio/patologia , Feminino , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Proteínas/metabolismo , RNA Mensageiro/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Proteínas Ativadoras de ras GTPase/metabolismo
20.
Oncol Rep ; 19(5): 1339-45, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18425396

RESUMO

This study was aimed at investigating the death-associated protein kinase (DAPK) promoter methylation and its clinical relevance in cervical cancer. The DAPK promoter methylation was detected by methylation-specific PCR (MSP) and correlated with DAPK mRNA and protein expression. The effect of DAPK expression on the radiosensitivity of the cervical cancer cell line was assessed by overexpressing DAPK in the radioresistant cell line SiHa. DAPK hypermethylation was found in 56.08% of the cervical cancer samples and was associated with the tumor histological cell type of squamous cell carcinoma (p=0.002) and advanced tumor stage (p=0.005). Subsequently, DAPK protein expression was found to significantly decrease in cervical cancer samples when compared to normal tissues. The DAPK mRNA and protein expression levels were absent or remarkably reduced in SiHa and HeLa in which the DAPK promoter was hypermethylated. The expression levels of DAPK could be restored after demethylation treatment with 5-aza-2'-deoxycytidine. Overexpressing DAPK in vitro had no significant influence to the survival of the radioresistant SiHa cell after being challenged by irradiation. Our findings suggest that DAPK might not directly be responsible for the cellular radiosensitivity, however, DAPK hypermethylation appeared to be of prognostic significance in the advanced stages of cervical cancer.


Assuntos
Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/fisiologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/genética , Proteínas Quinases Dependentes de Cálcio-Calmodulina/fisiologia , Metilação de DNA , Regiões Promotoras Genéticas , Neoplasias do Colo do Útero/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Ilhas de CpG , Proteínas Quinases Associadas com Morte Celular , Feminino , Perfilação da Expressão Gênica , Humanos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Tolerância a Radiação
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