RESUMO
BACKGROUND: Chronic low back pain (cLBP) is a common and highly disabling problem world-wide. Although many treatment options exist, it is unclear how to best sequence the multitude of care options to provide the greatest benefit to patients. METHODS: The Sequential and Comparative Evaluation of Pain Treatment Effectiveness Response (SCEPTER) trial uses a pragmatic, randomized, stepped design. Enrollment targets 2529 participants from 20 Veterans Affairs (VA) medical centers. Participants with chronic low back pain will first be randomized to one of three options: 1) an internet-based self-management program (Pain EASE); 2) a tailored physical therapy program (Enhanced PT); or 3) continued care with active monitoring (CCAM), a form of usual care. Participants not achieving a 30% or 2-point reduction on the study's primary outcome (Brief Pain Inventory Pain Interference (BPI-PI) subscale), 3 months after beginning treatment may undergo re-randomization in a second step to cognitive behavioral therapy for chronic pain, spinal manipulation therapy, or yoga. Secondary outcomes include pain intensity, back pain-related disability, depression, and others. Participants will be assessed every three months until 12 months after initiating their final trial therapy. Companion economic and implementation analyses are also planned. RESULTS: The SCEPTER trial is currently recruiting and enrolling participants. CONCLUSIONS: Trial results will inform treatment decisions for the stepped management of chronic low back pain - a common and disabling condition. Additional analyses will help tailor treatment selection to individual patient characteristics, promote efficient resource use, and identify implementation barriers of interventions. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT04142177.
Assuntos
Dor Crônica , Terapia Cognitivo-Comportamental , Dor Lombar , Humanos , Dor nas Costas , Dor Crônica/terapia , Dor Crônica/psicologia , Terapia Cognitivo-Comportamental/métodos , Dor Lombar/terapia , Dor Lombar/psicologia , Resultado do TratamentoRESUMO
Background. Millions of people are infected with hepatitis C virus (HCV) worldwide and 30% spontaneously clear the infection. Reasons for HCV clearance without antiviral treatment are not well understood. Methods. Blood was collected for DNA analysis from patients with chronic HCV infection or evidence of spontaneous clearance. To overcome anticipated limitations of small sample size, primary analyses consisted of a candidate gene analysis of 12 preselected genes based on known association with host immunologic response to HCV infection. To further reduce the impact of multiple testing on power, a single likelihood ratio test was conducted for each gene using all associated SNPs assayed on the Illumina Quad 610/660W chip. Step-down permutation methods were used to adjust for multiple testing in all analyses. Results. Ninety-five and 62 patients with HCV chronic infection or spontaneous clearance, respectively, were included for analysis. HLA-DQB1 (p = 1.76â10(-5)) and IL-6 (p = 0.0007) genes were significantly associated with spontaneous HCV clearance. IL-28B was not significantly associated with spontaneous clearance (p = 0.17). Conclusion. Our whole-gene analytic strategy identified a previously unreported association of IL-6 with spontaneous clearance of HCV infection. We also confirmed the finding that HLA-DQB1 is associated with spontaneous resolution of HCV infection.
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Variação Genética , Cadeias beta de HLA-DQ/genética , Hepacivirus/imunologia , Hepatite C/etiologia , Hepatite C/virologia , Interleucina-6/genética , Coinfecção , Feminino , Genótipo , Cadeias beta de HLA-DQ/imunologia , Anticorpos Anti-Hepatite C/imunologia , Hepatite C Crônica/genética , Hepatite C Crônica/imunologia , Hepatite C Crônica/virologia , Humanos , Desequilíbrio de Ligação , Masculino , Polimorfismo de Nucleotídeo Único , Carga ViralRESUMO
BACKGROUND: It is accepted that a woman's lifetime risk of developing breast cancer after menopause is reduced by early full term pregnancy and multiparity. This phenomenon is thought to be associated with the development and differentiation of the breast during pregnancy. METHODS: In order to understand the underlying molecular mechanisms of pregnancy induced breast cancer protection, we profiled and compared the transcriptomes of normal breast tissue biopsies from 71 parous (P) and 42 nulliparous (NP) healthy postmenopausal women using Affymetrix Human Genome U133 Plus 2.0 arrays. To validate the results, we performed real time PCR and immunohistochemistry. RESULTS: We identified 305 differentially expressed probesets (208 distinct genes). Of these, 267 probesets were up- and 38 down-regulated in parous breast samples; bioinformatics analysis using gene ontology enrichment revealed that up-regulated genes in the parous breast represented biological processes involving differentiation and development, anchoring of epithelial cells to the basement membrane, hemidesmosome and cell-substrate junction assembly, mRNA and RNA metabolic processes and RNA splicing machinery. The down-regulated genes represented biological processes that comprised cell proliferation, regulation of IGF-like growth factor receptor signaling, somatic stem cell maintenance, muscle cell differentiation and apoptosis. CONCLUSIONS: This study suggests that the differentiation of the breast imprints a genomic signature that is centered in the mRNA processing reactome. These findings indicate that pregnancy may induce a safeguard mechanism at post-transcriptional level that maintains the fidelity of the transcriptional process.
Assuntos
Mama/metabolismo , Perfilação da Expressão Gênica , Genoma Humano/genética , Paridade/genética , Idoso , Análise por Conglomerados , Ciclinas/genética , Ciclinas/metabolismo , Regulação para Baixo/genética , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Inclusão em Parafina , Gravidez , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcriptoma/genética , Regulação para Cima/genéticaRESUMO
Locally advanced breast cancer (LABC) was initially characterized as a large primary tumor (≥5 cm), associated with or without skin or chest-wall involvement, fixed axillary lymph nodes, or disease spread to the ipsilateral internal mammary or supraclavicular nodes. Since 2002, LABC has been reclassified to include smaller stage IIB tumors (2 to <5 cm) with lymph node involvement, or stages IIIA-IIIB (≥5 cm) with or without nodal involvement. Despite the rather common presentation of LABC, it remains a poorly understood and highly variable clinical presentation of breast cancer that is a challenge to treatment. Here, we characterized a panel of breast tumors of known stage, grade, and key clinical-pathological parameters for the expression of the protein ezrin, which is involved in promoting signaling of the PI3K-Akt-mTOR pathway in response to extracellular and tumor micro-environmental signals, and is involved in breast cancer invasion and metastasis. We show that ezrin, which resides primarily in the apical membrane in normal breast epithelium, relocalizes primarily to the cytoplasm in >80 % of traditional (T3) invasive ductal LABC tumors (≥5 cm). Cytoplasmic ezrin is very strongly associated with a single characteristic in breast cancer-large tumor size. In contrast, in large non-malignant fibroadenomas, ezrin staining was similar to that of normal breast epithelium. Small (T1, 1 cm) invasive ductal carcinomas displayed largely apical membrane and perinuclear ezrin localization with weak cytoplasmic staining. Cytoplasmic ezrin localization was also associated with positive lymph node status, but no other clinical-pathological features, including hormone receptor status, histological or nuclear grade of tumor cell. The cytoplasmic relocalization of ezrin may therefore represent a novel marker for large malignant tumor size, reflecting the unique biology of LABC.
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Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proteínas do Citoesqueleto/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Espaço Intracelular/metabolismo , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Transporte Proteico , Adulto JovemRESUMO
BACKGROUND: In patients with multiple primary melanomas (MPM), mean tumor thickness tends to decrease from the first melanoma to the second melanoma, and prognosis may be improved compared with the prognosis for patients who have a single primary melanoma (SPM). In this study, the authors compared the clinicopathologic features of patients with MPM and SPM to better characterize the differences between these 2 groups and to determine whether or not there is an inherent difference in tumor aggression. METHODS: In total, 788 patients with melanoma who were enrolled prospectively in the Interdisciplinary Melanoma Cooperative Group database from 2002 to 2008 were studied. Patients with SPM and with MPM were compared with regard to clinical and primary melanoma characteristics. RESULTS: Of 788 patients with melanoma, 61 patients (7.7%) had 2 or more primary melanomas. The incidence of developing a second primary melanoma 1 year and 5 years after initial melanoma diagnosis was 4.1% and 8.7%, respectively, and most of the risk accumulated within the first year. The incidence of MPM was greater in patients aged ≥60 years than in those aged ≤60 years. The absence or presence of mitosis and other tumor characteristics did not differ significantly between patients with SPM and patients with MPM (P = .61). CONCLUSIONS: No difference was observed in the presence or absence of mitoses, a marker of tumor proliferation, in SPM and MPM. Because it has been demonstrated that the presence of mitosis is a powerful prognostic marker, the current findings suggested that the tumors behave similarly in patients with SPM and patients with MPM. The authors concluded that differences in tumor thickness and prognosis between SPM and MPM more likely are caused by factors other than tumor biology, such as increased surveillance.
Assuntos
Melanoma/patologia , Neoplasias Primárias Múltiplas/patologia , Neoplasias Cutâneas/patologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mitose , PrognósticoRESUMO
Early pregnancy and multiparity are known to reduce the risk of women to develop breast cancer at menopause. Based on the knowledge that the differentiation of the breast induced by the hormones of pregnancy plays a major role in this protection, this work was performed with the purpose of identifying what differentiation-associated molecular changes persist in the breast until menopause. Core needle biopsies (CNB) obtained from the breast of 42 nulliparous (NP) and 71 parous (P) postmenopausal women were analyzed in morphology, immunocytochemistry and gene expression. Whereas in the NP breast, nuclei of epithelial cells were large and euchromatic, in the P breast they were small and hyperchromatic, showing strong methylation of histone 3 at lysine 9 and 27. Transcriptomic analysis performed using Affymetrix HG_U133 oligonucleotide arrays revealed that in CNB of the P breast, there were 267 upregulated probesets that comprised genes controlling chromatin organization, transcription regulation, splicing machinery, mRNA processing and noncoding elements including XIST. We concluded that the differentiation process induced by pregnancy is centered in chromatin remodeling and in the mRNA processing reactome, both of which emerge as important regulatory pathways. These are indicative of a safeguard step that maintains the fidelity of the transcription process, becoming the ultimate mechanism mediating the protection of the breast conferred by full-term pregnancy.
Assuntos
Biomarcadores/metabolismo , Mama/citologia , Mama/metabolismo , Diferenciação Celular , Montagem e Desmontagem da Cromatina/genética , Células Epiteliais/metabolismo , Pós-Menopausa/genética , Idoso , Feminino , Perfilação da Expressão Gênica , Humanos , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Paridade/genética , Gravidez , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The objective of this study was to comprehensively compare the genomic profiles in the breast of parous and nulliparous postmenopausal women to identify genes that permanently change their expression following pregnancy. The study was designed as a two-phase approach. In the discovery phase, we compared breast genomic profiles of 37 parous with 18 nulliparous postmenopausal women. In the validation phase, confirmation of the genomic patterns observed in the discovery phase was sought in an independent set of 30 parous and 22 nulliparous postmenopausal women. RNA was hybridized to Affymetrix HG_U133 Plus 2.0 oligonucleotide arrays containing probes to 54,675 transcripts, scanned and the images analyzed using Affymetrix GCOS software. Surrogate variable analysis, logistic regression, and significance analysis of microarrays were used to identify statistically significant differences in expression of genes. The false discovery rate (FDR) approach was used to control for multiple comparisons. We found that 208 genes (305 probe sets) were differentially expressed between parous and nulliparous women in both discovery and validation phases of the study at an FDR of 10% and with at least a 1.25-fold change. These genes are involved in regulation of transcription, centrosome organization, RNA splicing, cell-cycle control, adhesion, and differentiation. The results provide initial evidence that full-term pregnancy induces long-term genomic changes in the breast. The genomic signature of pregnancy could be used as an intermediate marker to assess potential chemopreventive interventions with hormones mimicking the effects of pregnancy for prevention of breast cancer.
Assuntos
Regulação da Expressão Gênica , Genômica , Adulto , Idoso , Adesão Celular , Ciclo Celular , Feminino , Humanos , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Paridade , Pós-Menopausa , Gravidez , Reprodutibilidade dos TestesRESUMO
PURPOSE: To identify a melanoma microRNA (miRNA) expression signature that is predictive of outcome and then evaluate its potential to improve risk stratification when added to the standard-of-care staging criteria. EXPERIMENTAL DESIGN: Total RNA was extracted from 59 formalin-fixed paraffin-embedded melanoma metastases and hybridized to miRNA arrays containing 911 probes. We then correlated miRNA expression with post-recurrence survival and other clinicopathologic criteria. RESULTS: We identified a signature of 18 miRNAs whose overexpression was significantly correlated with longer survival, defined as more than 18 months post-recurrence survival. Subsequent cross-validation showed that a small subset of these miRNAs can predict post-recurrence survival in metastatic melanoma with an estimated accuracy of 80.2% (95% confidence interval, 79.8-80.6%). In contrast to standard-of-care staging criteria, a six-miRNA signature significantly stratified stage III patients into "better" and "worse" prognostic categories, and a multivariate Cox regression analysis revealed the signature to be an independent predictor of survival. Furthermore, we showed that most miRNAs from the signature also showed differential expression between patients with better and worse prognoses in the corresponding paired primary melanoma. CONCLUSIONS: MiRNA signatures have potential as clinically relevant biomarkers of prognosis in metastatic melanoma. Our data suggest that molecularly based models of risk assessment can improve the standard staging criteria and support the incorporation of miRNAs into such models.
Assuntos
Melanoma/genética , MicroRNAs/análise , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/mortalidade , Neoplasias Cutâneas/genética , Biomarcadores Tumorais/genética , Feminino , Perfilação da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Masculino , Melanoma/mortalidade , Melanoma/patologia , MicroRNAs/genética , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Cutâneas/mortalidade , Neoplasias Cutâneas/patologiaRESUMO
OBJECT: Optimal treatment of primary and recurrent craniopharyngiomas remains controversial. Radical resection and limited resection plus radiation therapy yield similar rates of disease control and overall survival. The data are much less clear for recurrent tumors. The authors report their experience with radical resection of both primary and recurrent craniopharyngiomas in children and compare the outcomes between the 2 groups. METHODS: A retrospective analysis was performed in 86 children younger than 21 years of age who underwent a total of 103 operations for craniopharyngioma between 1986 and 2008; these were performed by the senior author. The goal was resection with curative intent in all patients. Two patients were lost to follow-up and were excluded from analysis. The mean age at the time of surgery was 9.6 years, and the mean follow-up was 9.0 years. RESULTS: All 57 children with primary tumors underwent gross-total resection (GTR). A GTR was achieved in significantly fewer children with recurrent tumors (18 [62%] of 29). There were 3 perioperative deaths (3%). Tumor recurred after GTR in 14 (20%) of 71 patients. Overall survival and progression-free survival were significantly better in patients with primary tumors at time of presentation to the authors' institution. There were no significant differences in the neurological, endocrinological, visual, or functional outcomes between patients with primary and those with recurrent tumors. Factors negatively affecting overall survival and progression-free survival include subtotal resection (recurrent tumors only), tumor size >or= 5 cm, or presence of hydrocephalus or a ventriculoperitoneal shunt. Prior radiation therapy and increasing tumor size were both risk factors for incomplete resection at reoperation. CONCLUSIONS: In the hands of surgeons with experience with craniopharyngiomas, the authors believe that radical resection at presentation offers the best chance of disease control and potential cure with acceptable morbidity. While GTR does not preclude recurrence and is more difficult to achieve in recurrent tumors, especially large and previously irradiated tumors, radical resection is still possible in patients with recurrent craniopharyngiomas with morbidity similar to that of primary tumors.
Assuntos
Craniofaringioma/cirurgia , Craniotomia/métodos , Microcirurgia/métodos , Recidiva Local de Neoplasia/cirurgia , Neoplasia Residual/cirurgia , Adolescente , Adulto , Índice de Massa Corporal , Criança , Pré-Escolar , Craniofaringioma/diagnóstico , Craniofaringioma/mortalidade , Progressão da Doença , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Hipopituitarismo/diagnóstico , Hipopituitarismo/etiologia , Doenças Hipotalâmicas/diagnóstico , Doenças Hipotalâmicas/etiologia , Lactente , Estimativa de Kaplan-Meier , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Masculino , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/mortalidade , Neoplasia Residual/diagnóstico , Neoplasia Residual/mortalidade , Exame Neurológico , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/etiologia , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Adulto JovemRESUMO
Although remission rates for metastatic melanoma are generally very poor, some patients can survive for prolonged periods following metastasis. We used gene expression profiling, mitotic index (MI), and quantification of tumor infiltrating leukocytes (TILs) and CD3+ cells in metastatic lesions to search for a molecular basis for this observation and to develop improved methods for predicting patient survival. We identified a group of 266 genes associated with postrecurrence survival. Genes positively associated with survival were predominantly immune response related (e.g., ICOS, CD3d, ZAP70, TRAT1, TARP, GZMK, LCK, CD2, CXCL13, CCL19, CCR7, VCAM1) while genes negatively associated with survival were cell proliferation related (e.g., PDE4D, CDK2, GREF1, NUSAP1, SPC24). Furthermore, any of the 4 parameters (prevalidated gene expression signature, TILs, CD3, and in particular MI) improved the ability of Tumor, Node, Metastasis (TNM) staging to predict postrecurrence survival; MI was the most significant contributor (HR = 2.13, P = 0.0008). An immune response gene expression signature and presence of TILs and CD3+ cells signify immune surveillance as a mechanism for prolonged survival in these patients and indicate improved patient subcategorization beyond current TNM staging.
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Regulação Neoplásica da Expressão Gênica/imunologia , Melanoma/diagnóstico , Melanoma/genética , Estadiamento de Neoplasias/métodos , Perfilação da Expressão Gênica/métodos , Humanos , Imuno-Histoquímica , Linfócitos do Interstício Tumoral/patologia , Melanoma/imunologia , Melanoma/secundário , Índice Mitótico/métodos , Análise de Sequência com Séries de Oligonucleotídeos , Prognóstico , Análise de SobrevidaRESUMO
The highly aggressive character of melanoma makes it an excellent model for probing the mechanisms underlying metastasis, which remains one of the most difficult challenges in treating cancer. We find that miR-182, member of a miRNA cluster in a chromosomal locus (7q31-34) frequently amplified in melanoma, is commonly up-regulated in human melanoma cell lines and tissue samples; this up-regulation correlates with gene copy number in a subset of melanoma cell lines. Moreover, miR-182 ectopic expression stimulates migration of melanoma cells in vitro and their metastatic potential in vivo, whereas miR-182 down-regulation impedes invasion and triggers apoptosis. We further show that miR-182 over-expression promotes migration and survival by directly repressing microphthalmia-associated transcription factor-M and FOXO3, whereas enhanced expression of either microphthalmia-associated transcription factor-M or FOXO3 blocks miR-182's proinvasive effects. In human tissues, expression of miR-182 increases with progression from primary to metastatic melanoma and inversely correlates with FOXO3 and microphthalmia-associated transcription factor levels. Our data provide a mechanism for invasion and survival in melanoma that could prove applicable to metastasis of other cancers and suggest that miRNA silencing may be a worthwhile therapeutic strategy.
Assuntos
Fatores de Transcrição Forkhead/genética , Regulação Neoplásica da Expressão Gênica , Melanoma/patologia , MicroRNAs/genética , Fator de Transcrição Associado à Microftalmia/genética , Metástase Neoplásica/genética , Animais , Movimento Celular , Sobrevivência Celular , Progressão da Doença , Proteína Forkhead Box O3 , Humanos , Camundongos , MicroRNAs/fisiologia , Células Tumorais CultivadasRESUMO
Asbestos and benzo(a)pyrene diol epoxide (BPDE) are pulmonary carcinogens with synergistic interaction in causing lung cancer. We used Affymetrix microarrays to study gene modulation in vitro using normal human bronchial epithelial cells exposed to chrysotile asbestos and/or BPDE for 4 or 24 h. Linear models were used to compare treated cells to controls at each time point to identify statistically significant up- or downregulation of genes. Profiles of genes regulated by chrysotile were dominated by cytokines, growth factors, and DNA damage. Profiles of genes with BPDE and chrysotile regulation were correlated with proliferation, DNA damage recognition and nucleotide-excision repair, cytokines, and apoptosis. Chemokines, growth-regulated oncogene-alpha (Gro-alpha, CXCL-1), and IL-8, were significantly increased, and these had previously been observed in bronchoalveolar lavage from asbestos workers or in animal models. Interestingly, the Hermansky-Pudlak gene, which is mutated in an autosomal recessive form of pulmonary fibrosis, was downregulated threefold by BPDE at 4 h. This is an interesting example of gene (Hermansky-Pudlak syndrome) and environment (BPDE) interaction. Transcription factors, including activating transcription factor 3 and Cbp/p300-interacting transactivator, were upregulated by chrysotile. Real Time PCR for IL-8, ATF-3, GADD45B, CXC Ligand 1, and CTGF compared to GAPDH validated microarray findings at 24 h. These in vitro findings in NHBE cells model environment-gene interaction for asbestos and BPDE, highlighting effects of inflammation, fibrosis, proliferation, and DNA damage recognition and repair.
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7,8-Di-Hidro-7,8-Di-Hidroxibenzo(a)pireno 9,10-óxido/toxicidade , Asbestos Serpentinas/toxicidade , Brônquios/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Perfilação da Expressão Gênica , Expressão Gênica/efeitos dos fármacos , Brônquios/citologia , Brônquios/metabolismo , Células Cultivadas , Regulação para Baixo , Sinergismo Farmacológico , Células Epiteliais/metabolismo , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Regulação para CimaRESUMO
Outcome for children with childhood acute lymphoblastic leukemia (ALL) who relapse is poor. To gain insight into the mechanisms of relapse, we analyzed gene-expression profiles in 35 matched diagnosis/relapse pairs as well as 60 uniformly treated children at relapse using the Affymetrix platform. Matched-pair analyses revealed significant differences in the expression of genes involved in cell-cycle regulation, DNA repair, and apoptosis between diagnostic and early-relapse samples. Many of these pathways have been implicated in tumorigenesis previously and are attractive targets for intervention strategies. In contrast, no common pattern of changes was observed among late-relapse pairs. Early-relapse samples were more likely to be similar to their respective diagnostic sample while we noted greater divergence in gene-expression patterns among late-relapse pairs. Comparison of expression profiles of early- versus late-relapse samples indicated that early-relapse clones were characterized by overexpression of biologic pathways associated with cell-cycle regulation. These results suggest that early-relapse results from the emergence of a related clone, characterized by the up-regulation of genes mediating cell proliferation. In contrast, late relapse appears to be mediated by diverse pathways.
Assuntos
Perfilação da Expressão Gênica , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Apoptose/genética , Ciclo Celular/genética , Proliferação de Células , Criança , Células Clonais/patologia , Reparo do DNA/genética , Humanos , Análise por Pareamento , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Recidiva , Fatores de TempoRESUMO
We think of cluster analysis as class discovery. That is, we assume that there is an unknown mapping called clustering structure that assigns a class label to each observation, and the goal of cluster analysis is to estimate this clustering structure, that is, to estimate the number of clusters and cluster assignments. In traditional cluster analysis, it is assumed that such unknown mapping is unique. However, since the observations may cluster in more than one way depending on the variables used, it is natural to permit the existence of more than one clustering structure. This generalized clustering problem of estimating multiple clustering structures is the focus of this paper. We propose an algorithm for finding multiple clustering structures of observations which involves clustering both variables and observations. The number of clustering structures is determined by the number of variable clusters. The dissimilarity measure for clustering variables is based on nearest-neighbor graphs. The observations are clustered using weighted distances with weights determined by the clusters of the variables. The motivating application is to gene expression data.
Assuntos
Algoritmos , Perfilação da Expressão Gênica/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Análise por Conglomerados , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , HumanosRESUMO
BACKGROUND: Uterine leiomyomas are extremely common and a major cause of pelvic pain, bleeding, infertility, and the leading indication for hysterectomy. Familial and epidemiological studies provide compelling evidence that genetic alterations play an important role in leiomyoma development. METHODS: Using Affymetrix U133A GeneChip we analysed expression profiles of 22,283 genes in paired samples of leiomyoma and adjacent normal myometrium. We compared our results with previously published data on gene expression in uterine leiomyoma and identified the overlapping gene alterations. RESULTS: We detected 80 genes with average differences of > or = 2-fold and false discovery rates of < 5% (14 overexpressed and 66 underexpressed). A comparative analysis including eight previous gene expression studies revealed eight prominent genes (ADH1, ATF3, CRABP2, CYR61, DPT, GRIA2, IGF2, MEST) identified by at least five different studies, eleven genes (ALDH1, CD24, CTGF, DCX, DUSP1, FOS, GAGEC1, IGFBP6, PTGDS, PTGER3, TYMS) reported by four studies, twelve genes (ABCA, ANXA1, APM2, CCL21, CDKN1A, CRMP1, EMP1, ESR1, FY, MAP3K5, TGFBR2, TIMP3) identified by three studies, and 40 genes reported by two different studies. CONCLUSIONS: Review of gene expression data revealed concordant changes in genes regulating retinoid synthesis, IGF metabolism, TGF-beta signaling and extracellular matrix formation. Gene expression studies provide clues to the relevant pathways of leiomyoma development.
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Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Leiomioma/genética , Neoplasias Uterinas/genética , Adulto , Regulação para Baixo , Feminino , Humanos , Leiomioma/etiologia , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Regulação para Cima , Neoplasias Uterinas/etiologiaRESUMO
PURPOSE: To retrospectively compare quantitative and qualitative methods of assessing magnetic resonance (MR) imaging contrast enhancement as the basis for diagnosing renal malignancy. MATERIALS AND METHODS: MR imaging was performed by using a gadolinium-enhanced breath-hold fat-suppressed three-dimensional T1-weighted gradient-echo sequence in 71 patients (48 men and 23 women; mean age, 62 years; age range, 26-87 years) with 93 renal lesions for which pathologic correlation was available. For quantitative measurements of enhancement, the relative increase in signal intensity values was measured by one investigator with manually defined regions of interest, and the threshold of an increase of 15% or greater was used to distinguish malignant from benign masses. For qualitative assessment, two investigators independently reviewed the subtracted images of all lesions and subjectively determined whether enhancement was present or absent. The sensitivity, specificity, and positive and negative predictive values for each method were calculated and compared. Mean (+/- standard deviation) and median values of relative enhancement were also calculated for benign and malignant lesions. RESULTS: At pathologic analysis, 74 (80%) of the 93 lesions were malignant, and 19 (20%)-including seven oncocytomas-were benign. For diagnosing malignancy based on enhancement alone, sensitivity and specificity, respectively, were 95% (70 of 74 lesions) and 53% (10 of 19 lesions) at quantitative analysis and 99% (73 of 74 lesions) and 58% (11 of 19 lesions) at qualitative analysis. All seven oncocytomas were considered to be malignant with both methods. When the oncocytomas were excluded, specificities increased to 83% (10 of 12 lesions) and 92% (11 of 12 lesions) for the quantitative and qualitative evaluations, respectively. Three of the four malignant lesions incorrectly characterized as benign at quantitative assessment were hyperintense on unenhanced MR images; all were diagnosed correctly at qualitative evaluation. CONCLUSION: Image subtraction enables accurate assessment of renal tumor enhancement, particularly in the setting of masses that are hyperintense on unenhanced MR images.