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1.
Clin Chem ; 66(1): 77-88, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31811004

RESUMO

BACKGROUND: The newest advances in DNA sequencing are based on technologies that perform massively parallel sequencing (MPS). Since 2006, the output from MPS platforms has increased from 20 Mb to >7 Tb. First-generation MPS platforms amplify individual DNA molecules to multiple copies and then interrogate the sequence of those molecules. Second-generation MPS analyzes single unamplified molecules to generate much longer sequence reads but with less output than first-generation MPS and lower first-pass accuracy. With MPS technologies, it is now possible to analyze genomes, exomes, a defined subset of genes, transcriptomes, and even methylation across the genome. These technologies have and will continue to completely transform the clinical practice. CONTENT: The major first- and second-generation MPS platforms and how they are used in clinical practice are discussed. SUMMARY: The ability to sequence terabases of DNA per run on an MPS platform will dramatically change how DNA sequencing is used in clinical practice. Currently, MPS of targeted gene panels is the most common use of this technology clinically, but as the cost for genome sequencing inches downward to $100, this may soon become the method of choice (with the caveat that, at least in the near term, clinical-grade genome sequencing with interpretation may cost much more than $100). Other uses of this technology include sequencing of a mixture of bacterial and viral species (metagenomics), as well as the characterization of methylation across the genome.


Assuntos
DNA/química , Sequenciamento de Nucleotídeos em Larga Escala/métodos , DNA/metabolismo , Metilação de DNA , Genoma Humano , Sequenciamento de Nucleotídeos em Larga Escala/instrumentação , Humanos , Metagenômica , Nanoestruturas/química , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
2.
BMC Cancer ; 19(1): 352, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30975103

RESUMO

BACKGROUND: High risk human papillomaviruses (HPV) plays important roles in the development of cervical cancer, a number of other anogenital cancer and they are increasingly found in oropharyngeal squamous cell carcinoma (OPSCC), however there has not been comprehensive analysis about the role how these viruses play in the development of OPSCC. METHODS: To characterize the physical status of HPV within OPSCC and to determine the effect this has throughout the host genome, we have performed 30-40X whole genome sequencing (WGS) on the BGI sequencing platform on 34 OPSCCs: 28 of which were HPV positive. We then examined the sequencing data to characterize the HPV copy number and HPV physical status to determine what effect they have on both HPV and human genome structural changes. RESULTS: WGS determined the HPV copy number across the viral genome. HPV copy number ranged from 1 copy to as high as 150 copies in each individual OPSCC. Independent of HPV copy number, most tumors had either a small or a very large deletion in the viral genome. We discovered that these deletions were the result of either HPV integration into the human genome or HPV-HPV sequence junctions. WGS revealed that ~ 70% of these tumors had HPV integrations within the human genome and HPV integration occurred independent of HPV copy number. Individual HPV integrations were found to be highly disruptive resulting in structural variations and copy number changes at or around the integration sites. CONCLUSIONS: WGS reveals that there is a great complexity in both HPV sequences present and the HPV integrations events in HPV positive OPSCCs tumors. Thus HPV may be playing different roles in the development of different OPSCCs and this further challenge the HPV-driven carcinogenesis model first proposed for cervical cancer.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Neoplasias Orofaríngeas/genética , Papillomaviridae/genética , Infecções por Papillomavirus/genética , Adulto , Idoso , Carcinogênese/genética , Carcinoma de Células Escamosas/patologia , DNA Viral/genética , DNA Viral/isolamento & purificação , Feminino , Dosagem de Genes , Genoma Humano/genética , Genoma Viral/genética , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Orofaríngeas/patologia , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/patologia , Integração Viral/genética , Sequenciamento Completo do Genoma
3.
Genes Chromosomes Cancer ; 56(1): 59-74, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27636103

RESUMO

Common fragile sites (CFS) are chromosome regions that are prone to form gaps or breaks in response to DNA replication stress. They are often found as hotspots for sister chromatid exchanges, deletions, and amplifications in different cancers. Many of the CFS regions are found to span genes whose genomic sequence is greater than 1 Mb, some of which have been demonstrated to function as important tumor suppressors. CFS regions are also hotspots for human papillomavirus (HPV) integrations in cervical cancer. We used mate-pair sequencing to examine HPV integration events and chromosomal structural variations in 34 oropharyngeal squamous cell carcinoma (OPSCC). We used endpoint PCR and Sanger sequencing to validate each HPV integration event and found HPV integrations preferentially occurred within CFS regions similar to what is observed in cervical cancer. We also found that many of the chromosomal alterations detected also occurred at or near the cytogenetic location of CFSs. Several large genes were also found to be recurrent targets of rearrangements, independent of HPV integrations, including CSMD1 (2.1Mb), LRP1B (1.9Mb), and LARGE1 (0.7Mb). Sanger sequencing revealed that the nucleotide sequences near to identified junction sites contained repetitive and AT-rich sequences that were shown to have the potential to form stem-loop DNA secondary structures that might stall DNA replication fork progression during replication stress. This could then cause increased instability in these regions which could lead to cancer development in human cells. Our findings suggest that CFSs and some specific large genes appear to play important roles in OPSCC. © 2016 Wiley Periodicals, Inc.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Sítios Frágeis do Cromossomo/genética , Rearranjo Gênico , Neoplasias Orofaríngeas/genética , Papillomaviridae/genética , Infecções por Papillomavirus/genética , Integração Viral/genética , Pareamento de Bases , Sequência de Bases , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/virologia , Aberrações Cromossômicas , Humanos , Proteínas de Membrana/genética , Neoplasias Orofaríngeas/patologia , Neoplasias Orofaríngeas/virologia , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Prognóstico , Receptores de LDL/genética , Homologia de Sequência do Ácido Nucleico , Proteínas Supressoras de Tumor
4.
Gynecol Oncol ; 146(2): 334-339, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28587748

RESUMO

INTRODUCTION: Cervical cancer is the fourth most common female cancer worldwide. The prognosis for women with advanced-stage or recurrent cervical cancer remains poor and response to treatment is variable. Standardized management protocols leave little room for individualization. We report on a novel blood-based liquid biopsy for specific PIK3CA mutations as a clinically useful biomarker in patients with invasive cervical cancer. METHODS: One hundred seventeen Hong Kong Chinese women with primary invasive cervical cancer and their pre-treatment plasma samples were investigated. Two PIK3CA mutations, p.E542K and p.E545K were measured in cell free DNA (cfDNA) extracted from plasma using droplet digital PCR. This liquid biopsy of PIK3CA in cervical cancer was correlated to clinico-pathological features to verify the potential of PIK3CA as a clinically useful molecular biomarker for predicting disease prognosis and monitoring for progression. RESULTS: PIK3CA mutations, either p.E542K or p.E545K, were detected in plasma cfDNA from 22.2% of the patients. PIK3CA mutation status was significantly correlated to median tumor size (p<0.01). PIK3CA mutations detected in the plasma were significantly associated with decreased disease-free survival and overall survival (p<0.05). CONCLUSIONS: As a liquid molecular biopsy, analysis of circulating PIK3CA mutations shows promise as a way to refine risk stratification of individual patients with cervical cancer, and provides a platform for further research to offer individualized therapy with the purpose of improving outcomes.


Assuntos
Adenocarcinoma/sangue , Biomarcadores Tumorais/sangue , Carcinoma de Células Escamosas/sangue , DNA de Neoplasias/sangue , Fosfatidilinositol 3-Quinases/genética , Neoplasias do Colo do Útero/sangue , Adenocarcinoma/genética , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Povo Asiático , Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Classe I de Fosfatidilinositol 3-Quinases , Análise Mutacional de DNA , Intervalo Livre de Doença , Estudos de Viabilidade , Feminino , Hong Kong , Humanos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Carga Tumoral , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/mortalidade , Neoplasias do Colo do Útero/patologia
5.
Cytogenet Genome Res ; 150(3-4): 185-193, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28245440

RESUMO

Human papillomaviruses (HPV) are responsible for the development of almost all cervical cancers. HPV is also found in 85% of anal cancer and in 50% of penile, vulvar, and vaginal cancers, and they are increasingly found in a subset of head and neck cancers, i.e., oropharyngeal squamous cell carcinomas (OPSCC). The model for how HPV causes cancer is derived from several decades of study on cervical cancer, and it is just presumed that this model is not only completely valid for cervical cancer but for all other HPV-driven cancers as well. Next-generation sequencing (NGS) has now provided the necessary tools to characterize genomic alterations in cancer cells and can precisely determine the physical status of HPV in those cells as well. We discuss recent discoveries from different applications of NGS in both cervical cancer and OPSCCs, including whole-genome sequencing and mate-pair NGS. We also discuss what NGS studies have revealed about the different ways that HPV can be involved in cancer formation, specifically comparing cervical cancer and OPSCC.


Assuntos
Alphapapillomavirus/patogenicidade , Carcinoma de Células Escamosas/virologia , Neoplasias Orofaríngeas/virologia , Neoplasias do Colo do Útero/virologia , Carcinoma de Células Escamosas/genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Neoplasias Orofaríngeas/genética , Neoplasias do Colo do Útero/genética
6.
Cytogenet Genome Res ; 150(3-4): 217-226, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28142148

RESUMO

High-risk human papillomaviruses (HPVs) are known to be associated with different anogenital cancers including cervical, anal, penile, and vaginal cancers. They are also found to be responsible for the dramatic increases in oropharyngeal squamous cell carcinoma (OPSCC) observed in the United States and Europe. The model for how high-risk HPVs induce cancer formation comes from studies of cervical cancer which usually involves integration of the HPV into the human genome and subsequent changes due to induced chromosomal instability. Recent work, discussed here, however suggests that this model may not be completely correct. In addition, we summarize studies now done in OPSCC which demonstrate that the role of HPV in these cancers may be different from that in cervical cancer. Finally, we propose new models for how HPV may be involved in the formation of these 2 cancers.


Assuntos
Alphapapillomavirus/patogenicidade , Carcinoma de Células Escamosas/virologia , Sítios Frágeis do Cromossomo , Neoplasias Orofaríngeas/virologia , Neoplasias do Colo do Útero/virologia , Feminino , Instabilidade Genômica , Humanos , Modelos Biológicos
7.
Int J Cancer ; 137(4): 776-83, 2015 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-25626421

RESUMO

Although the rates of cervical squamous cell carcinoma have been declining, the rates of cervical adenocarcinoma are increasing in some countries. Outcomes for advanced cervical adenocarcinoma remain poor. Precision mapping of genetic alterations in cervical adenocarcinoma may enable better selection of therapies and deliver improved outcomes when combined with new sequencing diagnostics. We present whole-exome sequencing results from 15 cervical adenocarcinomas and paired normal samples from Hong Kong Chinese women. These data revealed a heterogeneous mutation spectrum and identified several frequently altered genes including FAT1, ARID1A, ERBB2 and PIK3CA. Exome sequencing identified human papillomavirus (HPV) sequences in 13 tumors in which the HPV genome might have integrated into and hence disrupted the functions of certain exons, raising the possibility that HPV integration can alter pathways other than p53 and pRb. Together, these provisionary data suggest the potential for individualized therapies for cervical adenocarcinoma based on genomic information.


Assuntos
Adenocarcinoma/genética , Sequenciamento de Nucleotídeos em Larga Escala , Neoplasias do Colo do Útero/genética , Adenocarcinoma/patologia , Adenocarcinoma/virologia , Adulto , Idoso , Exoma , Feminino , Hong Kong , Humanos , Pessoa de Meia-Idade , Mutação , Estadiamento de Neoplasias , Papillomaviridae/genética , Papillomaviridae/patogenicidade , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia
8.
Cell Mol Life Sci ; 71(23): 4601-15, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25300511

RESUMO

Common fragile sites (CFSs) are large chromosomal regions that are hot-spots for alterations especially within cancer cells. The three most frequently expressed CFS regions (FRA3B, FRA16D and FRA6E) contain genes that span extremely large genomic regions (FHIT, WWOX and PARK2, respectively), and these genes were found to function as important tumor suppressors. Many other CFS regions contain extremely large genes that are also targets of alterations in multiple cancers, but none have yet been demonstrated to function as tumor suppressors. The loss of expression of just FHIT or WWOX has been found to be associated with a worse overall clinical outcome. Studies in different cancers have revealed that some cancers have decreased expression of multiple large CFS genes. This loss of expression could have a profound phenotypic effect on these cells. In this review, we will summarize the known large common fragile site genes and discuss their potential relationship to cancer development.


Assuntos
Sítios Frágeis do Cromossomo , Instabilidade Genômica , Neoplasias/genética , Animais , Genes Supressores de Tumor , Humanos , Neoplasias/patologia
9.
Aust N Z J Psychiatry ; 49(5): 471-80, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25526944

RESUMO

OBJECTIVE: The over-representation of mental illness among homeless people across the globe is well documented. However, there is a dearth of Australian literature on the mental health needs of homeless individuals. Furthermore, longitudinal research examining the factors that contribute to better housing outcomes among this population is sparse. The aim of this research is to describe the mental illness profile of a sample of homeless men in an Australian urban centre (in Sydney) and examine the factors associated with better housing outcomes at 12-month follow-up. METHODS: A longitudinal survey was administered to 253 homeless men who were involved in the Michael Project: a 3-year initiative which combined existing accommodation support services with assertive case management and access to coordinated additional specialist allied health and support services. A total of 107 participants were followed up 12 months later. The survey examined the demographics of the sample and lifetime mental disorder diagnoses, and also included psychological screeners for current substance use and dependence, psychological distress, psychosis, and post-traumatic stress. RESULTS: Consistent with existing literature, the prevalence of mental illness was significantly greater amongst this sample than the general Australian population. However, mental illness presentation was not associated with housing situation at 12-month follow-up. Instead, type of support service at baseline was the best predictor of housing outcome, wherein participants who received short to medium-term accommodation and support were significantly more likely to be housed in stable, long-term housing at the 12-month follow-up than participants who received outreach or emergency accommodation support. CONCLUSIONS: This study provides evidence to support an innovative support model for homeless people in Australia and contributes to the limited Australian research on mental illness in this population.


Assuntos
Habitação , Pessoas Mal Alojadas/psicologia , Pessoas Mal Alojadas/estatística & dados numéricos , Transtornos Mentais/diagnóstico , Adulto , Austrália/epidemiologia , Administração de Caso , Feminino , Seguimentos , Necessidades e Demandas de Serviços de Saúde , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Análise de Regressão , Autorrelato
10.
Genes Chromosomes Cancer ; 53(5): 392-401, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24481768

RESUMO

The common fragile sites (CFSs) are large regions of profound genomic instability found in all individuals. The frequent deletions and other alterations in these regions in multiple cancers has led to the discovery of a number of extremely large genes contained within these regions and several of the large CFS genes have already been demonstrated to function as tumor suppressors involved in the formation of many different cancers. To study the large CFS genes in oropharyngeal squamous cell carcinoma (OPSCC), we did RNA seq analysis from 11 head and neck cancer patients. This revealed that there are six large CFS genes which consistently had decreased expression in the tumor samples compared to their matched normal tissues. These six genes are PARK2, DLG2, NBEA, CTNNA3, DMD, and FHIT. PARK2 and FHIT are located within the two most frequently expressed CFSs and both have been demonstrated to function as tumor suppressors, while the other large genes are found to have frequent alterations in multiple cancers. Validation experiments using real time PCR indicated that over 60% of OPSCC tumors showed decreased expression for all six genes. Both HPV-positive and HPV-negative OPSCCs had similar proportions with loss of expression of these genes. Our results suggest that this selected group of large genes might serve as potential tumor suppressors involved in the development of OPSCCs. Further studies are needed to investigate whether the decreased expression observed is due to genomic instability within the CFS regions or the selection for alterations of specific large CFS genes.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Sítios Frágeis do Cromossomo/genética , Orofaringe/metabolismo , Neoplasias Faríngeas/metabolismo , Hidrolases Anidrido Ácido/genética , Hidrolases Anidrido Ácido/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/virologia , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Distrofina/genética , Distrofina/metabolismo , Feminino , Guanilato Quinases/genética , Guanilato Quinases/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Orofaringe/patologia , Papillomaviridae/isolamento & purificação , Neoplasias Faríngeas/genética , Neoplasias Faríngeas/virologia , Análise de Sequência de RNA , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , alfa Catenina/genética , alfa Catenina/metabolismo
11.
Blood ; 120(11): 2280-9, 2012 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-22855598

RESUMO

Peripheral T-cell lymphomas (PTCLs) are aggressive malignancies of mature T lymphocytes with 5-year overall survival rates of only ∼ 35%. Improvement in outcomes has been stymied by poor understanding of the genetics and molecular pathogenesis of PTCL, with a resulting paucity of molecular targets for therapy. We developed bioinformatic tools to identify chromosomal rearrangements using genome-wide, next-generation sequencing analysis of mate-pair DNA libraries and applied these tools to 16 PTCL patient tissue samples and 6 PTCL cell lines. Thirteen recurrent abnormalities were identified, of which 5 involved p53-related genes (TP53, TP63, CDKN2A, WWOX, and ANKRD11). Among these abnormalities were novel TP63 rearrangements encoding fusion proteins homologous to ΔNp63, a dominant-negative p63 isoform that inhibits the p53 pathway. TP63 rearrangements were seen in 11 (5.8%) of 190 PTCLs and were associated with inferior overall survival; they also were detected in 2 (1.2%) of 164 diffuse large B-cell lymphomas. As TP53 mutations are rare in PTCL compared with other malignancies, our findings suggest that a constellation of alternate genetic abnormalities may contribute to disruption of p53-associated tumor suppressor function in PTCL.


Assuntos
Rearranjo Gênico , Linfoma de Células T Periférico/genética , Mutação , Fatores de Transcrição/genética , Proteína Supressora de Tumor p53/genética , Proteínas Supressoras de Tumor/genética , Linhagem Celular Tumoral , Inibidor p16 de Quinase Dependente de Ciclina/química , Inibidor p16 de Quinase Dependente de Ciclina/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Análise Mutacional de DNA , Feminino , Estudo de Associação Genômica Ampla , Humanos , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/mortalidade , Linfoma Difuso de Grandes Células B/patologia , Linfoma de Células T Periférico/metabolismo , Linfoma de Células T Periférico/mortalidade , Linfoma de Células T Periférico/patologia , Masculino , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas de Fusão Oncogênica/química , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Oxirredutases/química , Oxirredutases/genética , Oxirredutases/metabolismo , Proteínas Repressoras/química , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Homologia de Sequência do Ácido Nucleico , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Proteína Supressora de Tumor p53/química , Proteína Supressora de Tumor p53/metabolismo , Proteínas Supressoras de Tumor/química , Proteínas Supressoras de Tumor/metabolismo , Estados Unidos , Oxidorredutase com Domínios WW
12.
J Neurol Neurosurg Psychiatry ; 85(11): 1265-72, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24604904

RESUMO

BACKGROUND: Inherited polyneuropathies often go undiagnosed. We investigated whole exome sequencing (WES) in utility to identify the genetic causes of diverse forms of inherited polyneuropathies without genetic diagnosis. METHODS: WES was applied to 24 cases from 15 kindreds. These kindreds had earlier unsuccessful candidate gene testing and five probands were initially thought to have acquired neuropathy. We assessed the efficacy of WES in screening 74 known neuropathy genes and 5195 reported pathogenic mutations for hereditary motor and sensory neuropathy, distal hereditary motor neuropathy, hereditary sensory and autonomic neuropathy, complicated hereditary spastic paraplegia, and select hereditary metabolic neuropathies. RESULTS: Pathogenic mutations were identified in five kindreds: (1) ATL1-p.Val253Ile; (2) LITAF-p.Gly112Ser; (3) MFN2-p.Arg94Gln; (4) GARS-p.Ile334Phe; and (5) BSCL2-p.Ser 90Leu. Complexities in establishing inheritance, difficulties in selecting candidate genes and high cost of gene testing all hindered earlier gene discoveries. WES expanded the phenotypic spectrum of the identified known mutations. Possible causal mutations in known genes (SPTLC1, DCTN1, REEP1) were identified in three kindreds. In the remaining seven kindreds, multiple rare or novel variants were identified in novel genes not previously linked with neuropathy. Our results demonstrate an average sequencing depth of 140×, >98% coverage and >10× sequencing depth for 93% (range 89%-96%) of the diverse neuropathy genes and their known mutations. CONCLUSIONS: Diverse inherited neuropathy patients without genetic discovery by candidate gene testing have a favourable probability of receiving a genetic diagnosis by WES. Frequently, atypical phenotypes account for earlier failed candidate approaches, and WES is demonstrated to expand the clinical spectrum of known pathogenic mutations.


Assuntos
Exoma/genética , Polineuropatias/genética , Adolescente , Adulto , Algoritmos , Criança , Pré-Escolar , Feminino , Genes/genética , Predisposição Genética para Doença/genética , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Mutação/genética , Linhagem , Polineuropatias/diagnóstico , Análise de Sequência de DNA/métodos , Adulto Jovem
13.
Am J Hum Genet ; 87(1): 75-89, 2010 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-20598272

RESUMO

Common fragile sites (CFSs) are specific chromosome regions that exhibit an increased frequency of breaks when cells are exposed to a DNA-replication inhibitor such as aphidicolin. PARK2 and DMD, the causative genes for autosomal-recessive juvenile Parkinsonism and Duchenne and Becker muscular dystrophy, respectively, are two very large genes that are located within aphidicolin-induced CFSs. Gross rearrangements within these two genes are frequently observed as the causative mutations for these diseases, and similar alterations within the large fragile sites that surround these genes are frequently observed in cancer cells. To elucidate the molecular mechanisms underlying this fragility, we performed a custom-designed high-density comparative genomic hybridization analysis to determine the junction sequences of approximately 500 breakpoints in germ cell lines and cancer cell lines involving PARK2 or DMD. The sequence signatures where these breakpoints occur share some similar features both in germ cell lines and in cancer cell lines. Detailed analyses of these structures revealed that microhomologies are predominantly involved in rearrangement processes. Furthermore, breakpoint-clustering regions coincide with the latest-replicating region and with large nuclear-lamina-associated domains and are flanked by the highest-flexibility peaks and R/G band boundaries, suggesting that factors affecting replication timing collectively contribute to the vulnerability for rearrangement in both germ cell and somatic cell lines.


Assuntos
Instabilidade Cromossômica , Distrofina/genética , Células Germinativas/metabolismo , Distrofia Muscular de Duchenne/genética , Transtornos Parkinsonianos/genética , Ubiquitina-Proteína Ligases/genética , Sequência de Bases , Linhagem Celular Tumoral , Sítios Frágeis do Cromossomo , Replicação do DNA , Rearranjo Gênico , Loci Gênicos , Células Germinativas/citologia , Humanos , Masculino , Mutação , Análise de Sequência com Séries de Oligonucleotídeos
14.
Blood ; 117(3): 915-9, 2011 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-21030553

RESUMO

The genetics of peripheral T-cell lymphomas are poorly understood. The most well-characterized abnormalities are translocations involving ALK, occurring in approximately half of anaplastic large cell lymphomas (ALCLs). To gain insight into the genetics of ALCLs lacking ALK translocations, we combined mate-pair DNA library construction, massively parallel ("Next Generation") sequencing, and a novel bioinformatic algorithm. We identified a balanced translocation disrupting the DUSP22 phosphatase gene on 6p25.3 and adjoining the FRA7H fragile site on 7q32.3 in a systemic ALK-negative ALCL. Using fluorescence in situ hybridization, we demonstrated that the t(6;7)(p25.3;q32.3) was recurrent in ALK-negative ALCLs. Furthermore, t(6;7)(p25.3;q32.3) was associated with down-regulation of DUSP22 and up-regulation of MIR29 microRNAs on 7q32.3. These findings represent the first recurrent translocation reported in ALK-negative ALCL and highlight the utility of massively parallel genomic sequencing to discover novel translocations in lymphoma and other cancers.


Assuntos
Cromossomos Humanos Par 6/genética , Cromossomos Humanos Par 7/genética , Linfoma Anaplásico de Células Grandes/genética , Translocação Genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Quinase do Linfoma Anaplásico , Sequência de Bases , Quebra Cromossômica , Pontos de Quebra do Cromossomo , Fosfatases de Especificidade Dupla/genética , Feminino , Humanos , Hibridização in Situ Fluorescente , Linfoma Anaplásico de Células Grandes/patologia , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Fosfatases da Proteína Quinase Ativada por Mitógeno/genética , Dados de Sequência Molecular , Proteínas Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases , Análise de Sequência de DNA/métodos
15.
Am J Hematol ; 88(9): 741-6, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23733509

RESUMO

We used high resolution mate-pair sequencing (HRMPS) in 15 patients with primary myelofibrosis (PMF): eight with normal karyotype and seven with PMF-characteristic cytogenetic abnormalities, including der(6)t(1;6)(q21-23;p21.3) (n = 4), der(7)t(1;7)(q10;p10) (n = 2), del(20)(q11.2q13.3) (n = 3), and complex karyotype (n = 1). We describe seven novel deletions/translocations in five patients (including two with normal karyotype) whose breakpoints were PCR-validated and involved MACROD2, CACNA2D4, TET2, SGMS2, LRBA, SH3D19, INTS3, FOP (CHTOP), SCLT1, and PHF17. Deletions with breakpoints involving MACROD2 (lysine deacetylase; 20p12.1) were recurrent and found in two of the 15 study patients. A novel fusion transcript was found in one of the study patients (INTS3-CHTOP), and also in an additional non-study patient with PMF. In two patients with der(6)t(1;6)(q21-23;p21.3), we were able to map the precise translocation breakpoints, which involved KCNN3 and GUSBP2 in one case and HYDIN2 in another. This study demonstrates the utility of HRMPS in uncovering submicroscopic deletions/translocations/fusions, and precise mapping of breakpoints in those with overt cytogenetic abnormalities. The overall results confirm the genetic heterogeneity of PMF, given the low frequency of recurrent specific abnormalities, identified by this screening strategy. Currently, we are pursuing the pathogenetic relevance of some of the aforementioned findings.


Assuntos
Sequência de Bases , Proteínas de Fusão Oncogênica/genética , Mielofibrose Primária/genética , Análise de Sequência de DNA/métodos , Deleção de Sequência , Translocação Genética , Idoso , Pontos de Quebra do Cromossomo , Mapeamento Cromossômico , Cromossomos Humanos Par 1 , Cromossomos Humanos Par 6 , Cromossomos Humanos Par 7 , Feminino , Heterogeneidade Genética , Humanos , Cariotipagem , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mielofibrose Primária/patologia
16.
Insects ; 14(3)2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36975990

RESUMO

Invasive insects pose an increasing risk to global agriculture, environmental stability, and public health. Giant pine scale (GPS), Marchalina hellenica Gennadius (Hemiptera: Marchalinidae), is a phloem feeding scale insect endemic to the Eastern Mediterranean Basin, where it primarily feeds on Pinus halepensis and other Pinaceae. In 2014, GPS was detected in the southeast of Melbourne, Victoria, Australia, infesting the novel host Pinus radiata. An eradication program was unsuccessful, and with this insect now established within the state, containment and management efforts are underway to stop its spread; however, there remains a need to understand the insect's phenology and behaviour in Australia to better inform control efforts. We documented the annual life cycle and seasonal fluctuations in activity of GPS in Australia over a 32 month period at two contrasting field sites. Onset and duration of life stages were comparable to seasons in Mediterranean conspecifics, although the results imply the timing of GPS life stage progression is broadening or accelerating. GPS density was higher in Australia compared to Mediterranean reports, possibly due to the absence of key natural predators, such as the silver fly, Neoleucopis kartliana Tanasijtshuk (Diptera, Chamaemyiidae). Insect density and honeydew production in the Australian GPS population studied varied among locations and between generations. Although insect activity was well explained by climate, conditions recorded inside infested bark fissures often provided the weakest explanation of GPS activity. Our findings suggest that GPS activity is strongly influenced by climate, and this may in part be related to changes in host quality. An improved understanding of how our changing climate is influencing the phenology of phloem feeding insects such as GPS will help with predictions as to where these insects are likely to flourish and assist with management programs for pest species.

17.
Bioinformatics ; 27(12): 1708-10, 2011 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-21546395

RESUMO

MOTIVATION: Fusion transcripts can be created as a result of genome rearrangement in cancer. Some of them play important roles in carcinogenesis, and can serve as diagnostic and therapeutic targets. With more and more cancer genomes being sequenced by next-generation sequencing technologies, we believe an efficient tool for reliably identifying fusion transcripts will be desirable for many groups. RESULTS: We designed and implemented an open-source software tool, called FusionHunter, which reliably identifies fusion transcripts from transcriptional analysis of paired-end RNA-seq. We show that FusionHunter can accurately detect fusions that were previously confirmed by RT-PCR in a publicly available dataset. The purpose of FusionHunter is to identify potential fusions with high sensitivity and specificity and to guide further functional validation in the laboratory. AVAILABILITY: http://bioen-compbio.bioen.illinois.edu/FusionHunter/.


Assuntos
Fusão Gênica , Genes Neoplásicos , RNA Mensageiro/química , RNA Neoplásico/química , Análise de Sequência de RNA , Software , Humanos , Neoplasias/genética
18.
Int J Gynecol Pathol ; 31(3): 195-205, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22498935

RESUMO

Endometrial cancer is associated with numeric and structural chromosomal abnormalities, microsatellite instability (MSI), and alterations that activate oncogenes and inactivate tumor suppressor genes. The aim of this study was to characterize a set of endometrial cancers using multiple molecular genetic and immunohistochemical techniques. Ninety-six cases were examined for genomic alterations by MSI, MLH1 promoter hypermethylation, p53 and mismatch repair protein expression (MLH1, MSH2, MSH6, PMS2), and PTEN, PIK3CA, KRAS, and BRAF mutation analysis. At least 1 alteration was identified in 48 of 87 (55%) specimens tested for PTEN, making it the most common abnormality in this study. A PIK3CA alteration was observed in 16 (17%) specimens. Twenty-nine of 94 (31%) MSI tested tumors exhibited an MSI-H phenotype. Of the 29 MSI-H cases, 24 (83%) were positive for methylation of the MLH1 promoter region. Twenty-three (82%) of the 28 MSI-H cases with immunohistochemistry results showed loss of expression of MLH1/PMS2 (n=19), MSH2/MSH6 (n=2), or MSH6 only (n=2). Of the 19 MSI-H cases with loss of MLH1/PMS2 on immunohistochemistry, 18 were positive, and 1 was equivocal for MLH1 promoter hypermethylation. Twelve of 94 cases (13%) analyzed for KRAS mutations were found to have a mutation. No BRAF V600E mutations were indentified. This study provides a comprehensive molecular genetic analysis of commonly analyzed targets in a large cohort of endometrial cancers.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Reparo de Erro de Pareamento de DNA/genética , DNA de Neoplasias/genética , Neoplasias do Endométrio/genética , Hidrolases/genética , Instabilidade de Microssatélites , Proteínas Nucleares/genética , Fosfotransferases/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Idoso , Classe I de Fosfatidilinositol 3-Quinases , Estudos de Coortes , Análise Mutacional de DNA , Neoplasias do Endométrio/metabolismo , Feminino , Humanos , Metilação , Proteína 1 Homóloga a MutL , Mutação/genética , Proteínas Nucleares/metabolismo , PTEN Fosfo-Hidrolase/genética , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras) , Estudos Retrospectivos , Proteína Supressora de Tumor p53/metabolismo , Proteínas ras/genética
19.
Cancer Cell ; 1(1): 89-97, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12086891

RESUMO

Oncogene amplification is an important process in human tumorigenesis, but its underlying mechanism is currently unknown. Cytogenetic analysis indicates that amplification of drug-selected genes in rodent cells is driven by recurrent breaks within chromosomal common fragile sites (CFSs), via the breakage-fusion-bridge (BFB) mechanism. Here we show that BFB cycles drive the intrachromosomal amplification of the MET oncogene in a human gastric carcinoma. Our molecular evidence includes a "ladder-like" structure and inverted repeat organization of the MET amplicons. Furthermore, we show that the breakpoints, setting the centromeric amplicon boundaries, are within the CFS FRA7G region. Upon replication stress, this region showed perturbed chromatin organization, predisposing it to breakage. Thus, in vivo induction of CFSs can play an important role in human oncogenesis.


Assuntos
Fragilidade Cromossômica/genética , Amplificação de Genes/genética , Oncogenes/genética , Proteínas Proto-Oncogênicas c-met/genética , Neoplasias Gástricas/genética , Centrômero/fisiologia , Cromatina/genética , Aberrações Cromossômicas , Transtornos Cromossômicos , Sítios Frágeis do Cromossomo , Humanos , Hibridização in Situ Fluorescente , Cariotipagem , Proteínas Proto-Oncogênicas c-met/metabolismo , Sequências Repetitivas de Ácido Nucleico , Células Tumorais Cultivadas
20.
RNA Biol ; 8(3): 496-505, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21532345

RESUMO

More than 98% of the human genome is comprised of non-protein coding sequences. Interestingly, a considerable fraction of these sequences is transcribed into non-protein coding RNA transcripts. These transcripts range in size from very small RNAs such as the miRNAs (20-25 base pairs) to transcripts that can range up to 100 kb or more. Some longer non-coding RNAs (lncRNAs) have been found to play important regulatory roles within cells. In this report, we demonstrate that LSINCT5 is a 2.6 Kb polyadenylated, long stress-induced non-coding transcript that is on the negative strand, localized in the nucleus and potentially transcribed by RNA polymerase III. LSINCT5 is overexpressed in breast and ovarian cancer cell lines and tumor tissues, relative to their normal counterpart. In addition, knocking down the expression of LSINCT5 in cancer-derived cell lines causes a decrease in cellular proliferation. Finally, we identified 95 genes with more than 2-fold changes when knocking down LSINCT5 expression by using the Affymetrix U133 Plus 2 array. We chose a subset of these genes to validate using qPCR and found that ten of these genes were indeed significantly affected by the LSINCT5 knockdown. Interestingly, two genes that were significantly downregulated were the lncRNA NEAT-1 and a protein coding gene PSPC1. We have therefore characterized a novel lncRNA that is overexpressed in breast and ovarian cancers, enhances cellular proliferation and may play a significant role in multiple processes.


Assuntos
Neoplasias da Mama/metabolismo , Proliferação de Células , Neoplasias Ovarianas/metabolismo , RNA não Traduzido/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Regulação para Baixo , Feminino , Genoma Humano , Humanos , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , RNA não Traduzido/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
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