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1.
JCO Precis Oncol ; 6: e2200010, 2022 08.
Article de Anglais | MEDLINE | ID: mdl-35952316

RÉSUMÉ

PURPOSE: The recommended duration of adjuvant fluoropyrimidine and oxaliplatin chemotherapy for patients with stage III colon cancer is based on tumor classification into clinically low-risk (T1-3 N1) and high-risk (T4 or N2) groups. We determined whether Immunoscore can enhance prognostication within these risk groups. MATERIALS AND METHODS: Patients with stage III colon carcinomas (N = 600) were randomly selected from the infusional fluorouracil, leucovorin, and oxaliplatin arm of adjuvant trial NCCTG N0147 (Alliance for Clinical Trials in Oncology). Tumors were evaluated for Immunoscore that quantifies CD3+ and CD8+ T-cell densities in the tumor center and invasive margin by digital image analysis. Disease-free survival (DFS) by Immunoscore was analyzed using a multivariable Cox regression model in each risk group with adjustment for covariates including KRAS, BRAFV600E, and mismatch repair status. RESULTS: Of 559 cancers with Immunoscore data, 299 (53.5%) were classified as clinically low-risk (T1-3 N1) and 260 (46.5%) as clinically high-risk (T4 and/or N2). Among patients with low-risk tumors, those with Immunoscore-Low versus Immunoscore-High tumors had significantly worse 5-year DFS rates (77.5% v 91.8%; hazard ratio, 1.70; 95% CI, 1.03 to 2.79; P = .037). Among patients with high-risk tumors, those with Immunoscore-Low versus Immunoscore-High tumors also had significantly worse DFS (55.3% v 70.3%; hazard ratio, 1.65; 95% CI, 1.11 to 2.47; P = .013). Tumors that were low-risk/Immunoscore-Low had similar outcomes as did tumors that were high-risk/Immunoscore-High (P = .174). Prognostication was significantly improved in multivariable models where Immunoscore was added to clinical risk parameters and limited biomarkers (likelihood ratio test P = .0003). CONCLUSION: Immunoscore can refine patient prognosis beyond clinical risk group classification, suggesting its potential utility for adjuvant decision making.


Sujet(s)
Carcinomes , Tumeurs du côlon , Protocoles de polychimiothérapie antinéoplasique/effets indésirables , Carcinomes/traitement médicamenteux , Tumeurs du côlon/traitement médicamenteux , Fluorouracil/usage thérapeutique , Humains , Leucovorine/usage thérapeutique , Stadification tumorale , Composés organiques du platine/usage thérapeutique , Oxaliplatine/usage thérapeutique , Pronostic
2.
Cancers (Basel) ; 13(21)2021 Oct 30.
Article de Anglais | MEDLINE | ID: mdl-34771628

RÉSUMÉ

BACKGROUND: Adjuvant chemotherapy use in stage II colon cancer is controversial. Current prognostic risk factors do not take the tumor immune microenvironment into account. Consideration of the Immunoscore, which measures the host immune response at the tumor site, may assist clinicians in reducing adjuvant chemotherapy use in patients who are unlikely to benefit from it. This study sought to determine the potential clinical utility of the Immunoscore, via its effect on medical oncologists' recommendations for management of patients with stage II colon cancer. METHODS: De-identified vignettes of 10 patients with stage II colon cancer were presented to 25 practicing medical oncologists. Each participant completed surveys indicating recommendations for adjuvant chemotherapy and surveillance strategies. An educational session was subsequently conducted, and the same patient profiles were re-presented but included immunoscore results. Participants were again asked to provide their recommendations. A participant was counted as influenced if their responses were altered after immunoscore test results were provided. RESULTS: All but one participant (96%) altered a management recommendation for ≥1 case. For individual cases, a mean of 55% (range, 40-80%) of participants altered their recommendations for adjuvant chemotherapy and/or surveillance. For the immunoscore-high cases (low-risk of recurrence), recommendations for adjuvant chemotherapy use decreased from 60% to 31%. CONCLUSIONS: These results indicate a willingness by oncologists to integrate immunoscore information into clinical practice recommendations. Incorporation of immunoscore data resulted in the reduction of nonvalue care in the simulated population. Confirmation in prospective studies is planned.

3.
Oncologist ; 25(11): e1807-e1811, 2020 11.
Article de Anglais | MEDLINE | ID: mdl-32893931

RÉSUMÉ

BACKGROUND: Although recent advances in immunotherapy have transformed the treatment landscape for many anatomically defined cancers, these therapies are currently not approved for patients diagnosed with cancer of unknown primary (CUP). Molecular cancer classification using gene expression profiling (GEP) assays has the potential to identify tumor type and putative primary cancers and thereby may allow consideration of immune checkpoint inhibitor (ICI) therapy options for a subset of patients with CUP. Herein, we evaluated and characterized the ability of a 92-gene assay (CancerTYPE ID) to provide a molecular diagnosis and identify putative tumor types that are known to be sensitive to ICI therapies in patients with CUP or uncertain diagnosis. FINDINGS: A total of 24,426 cases from a large-scale research database of 92-gene assay clinical cases were classified, of which 9,350 (38%) were predicted to have an ICI-eligible tumor type. All ICIs with approved indications as of March 2020 were included in the analysis. Non-small cell lung cancer (NSCLC) was the most frequent molecular diagnosis and accounted for 33% of the ICI-eligible tumor types identified and 13% of the overall reportable results. In addition to NSCLC, the assay also frequently identified urothelial carcinomas, gastric cancer, and head and neck squamous cell carcinoma. The distributions of identified tumor types with indications for ICI therapy were similar across age and gender. CONCLUSIONS: Results suggest that molecular profiling with the 92-gene assay identifies a subset of ICI-eligible putative primary cancers in patients with CUP. We propose a treatment strategy based on available tests, including clinicopathologic features, GEP, and ICI biomarkers of response.


Sujet(s)
Carcinome pulmonaire non à petites cellules , Tumeurs du poumon , Métastases d'origine inconnue , Carcinome pulmonaire non à petites cellules/traitement médicamenteux , Carcinome pulmonaire non à petites cellules/génétique , Analyse de profil d'expression de gènes , Humains , Immunothérapie , Métastases d'origine inconnue/traitement médicamenteux , Métastases d'origine inconnue/génétique
4.
BMC Genomics ; 18(1): 231, 2017 03 14.
Article de Anglais | MEDLINE | ID: mdl-28288568

RÉSUMÉ

BACKGROUND: Human papillomavirus (HPV) is the carcinogen of almost all invasive cervical cancer and a major cause of oral and other anogenital malignancies. HPV genotyping by dideoxy (Sanger) sequencing is currently the reference method of choice for clinical diagnostics. However, for samples with multiple HPV infections, genotype identification is singular and occasionally imprecise or indeterminable due to overlapping chromatograms. Our aim was to explore and compare HPV metagenomes in abnormal cervical cytology by deep sequencing for correlation with disease states. RESULTS: Low- and high-grade intraepithelial lesion (LSIL and HSIL) cytology samples were DNA extracted for PCR-amplification of the HPV E6/E7 genes. HPV+ samples were sequenced by dideoxy and deep methods. Deep sequencing revealed ~60% of all samples (n = 72) were multi-HPV infected. Among LSIL samples (n = 43), 27 different genotypes were found. The 3 dominant (most abundant) genotypes were: HPV-39, 11/43 (26%); -16, 9/43 (21%); and -35, 4/43 (9%). Among HSIL (n = 29), 17 HPV genotypes were identified; the 3 dominant genotypes were: HPV-16, 21/29 (72%); -35, 4/29 (14%); and -39, 3/29 (10%). Phylogenetically, type-specific E6/E7 genetic distances correlated with carcinogenic potential. Species diversity analysis between LSIL and HSIL revealed loss of HPV diversity and domination by HPV-16 in HSIL samples. CONCLUSIONS: Deep sequencing resolves HPV genotype composition within multi-infected cervical cytology. Biodiversity analysis reveals loss of diversity and gain of dominance by carcinogenic genotypes in high-grade cytology. Metagenomic profiles may therefore serve as a biomarker of disease severity and a population surveillance tool for emerging genotypes.


Sujet(s)
Protéines des oncogènes viraux/génétique , Papillomaviridae/génétique , Protéines E7 de papillomavirus/génétique , Séquence nucléotidique , ADN viral/composition chimique , ADN viral/isolement et purification , ADN viral/métabolisme , Évolution moléculaire , Femelle , Locus génétiques , Génotype , Séquençage nucléotidique à haut débit , Humains , Grading des tumeurs , Protéines des oncogènes viraux/classification , Papillomaviridae/métabolisme , Protéines E7 de papillomavirus/classification , Phylogenèse , Analyse de séquence d'ADN , Tumeurs du col de l'utérus/anatomopathologie , Tumeurs du col de l'utérus/virologie
5.
Clin Epigenetics ; 8: 96, 2016.
Article de Anglais | MEDLINE | ID: mdl-27651839

RÉSUMÉ

BACKGROUND: The Pap smear has remained the foundation for cervical cancer screening for over 70 years. With advancements in molecular diagnostics, primary high-risk human papillomavirus (hrHPV) screening has recently become an accepted stand-alone or co-test with conventional cytology. However, both diagnostic tests have distinct limitations. The aim of this study was to determine the association between HPV genotypes and cellular epigenetic modifications in three grades of cervical cytology for screening biomarker discovery. METHODS: This prospective, cross-sectional study used residual liquid-based cytology samples for HPV genotyping and epigenetic analysis. Extracted DNA was subjected to parallel polymerase chain reactions using three primer sets (MY09/11, FAP59/64, E6-E7 F/B) for HPV DNA amplification. HPV+ samples were genotyped by DNA sequencing. Promoter methylation of four candidate tumor suppressor genes (adenylate cyclase 8 (ADCY8), cadherin 8, type 2 (CDH8), MGMT, and zinc finger protein 582 (ZNF582)) out of 48 genes screened was quantified by bisulfite-pyrosequencing of genomic DNA. Independent validation of methylation profiles was performed by analyzing data from cervical cancer cell lines and clinical samples from The Cancer Genome Atlas (TCGA). RESULTS: Two hundred seventy-seven quality cytology samples were analyzed. HPV was detected in 31/100 (31 %) negative for intraepithelial lesion or malignancy (NILM), 95/100 (95 %) low-grade squamous intraepithelial lesion (LSIL), and 71/77 (92 %) high-grade squamous intraepithelial lesion (HSIL) samples. The proportion of IARC-defined carcinogenic HPV types in sequenced samples correlated with worsening grade: NILM 7/29 (24 %), LSIL 53/92 (58 %), and HSIL 65/70 (93 %). Promoter methylation of ADCY8, CDH8, and ZNF582 was measured in 170 samples: NILM (N = 33), LSIL (N = 70), and HSIL (N = 67) also correlated with worsening grade. Similar hypermethylation patterns were found in cancer cell lines and TCGA samples. The combination of four biomarkers, i.e., HPV genotype and three-gene promoter methylation, predicted HSIL (AUC 0.89) better than HPV alone (AUC 0.74) by logistic regression and probabilistic modeling. CONCLUSIONS: HPV genotype and DNA methylation of ADCY8, CDH8, and ZNF582 are correlated with cytological grade. Collectively, these biomarkers may serve as a molecular classifier of Pap smears.


Sujet(s)
Adenylate Cyclase/génétique , Cadhérines/génétique , Méthylation de l'ADN , Facteurs de transcription Krüppel-like/génétique , Papillomaviridae/génétique , Infections à papillomavirus/diagnostic , Tumeurs du col de l'utérus/épidémiologie , Tumeurs du col de l'utérus/anatomopathologie , Adulte , Lignée cellulaire tumorale , Études transversales , ADN viral/analyse , Dépistage précoce du cancer , Femelle , Génotype , Humains , Adulte d'âge moyen , Grading des tumeurs , Test de Papanicolaou/méthodes , Infections à papillomavirus/épidémiologie , Régions promotrices (génétique) , Études prospectives , Analyse de séquence d'ADN/méthodes , Lésions malpighiennes intra-épithéliales du col utérin/épidémiologie , Lésions malpighiennes intra-épithéliales du col utérin/génétique , Lésions malpighiennes intra-épithéliales du col utérin/anatomopathologie , Lésions malpighiennes intra-épithéliales du col utérin/virologie , Tumeurs du col de l'utérus/génétique , Tumeurs du col de l'utérus/virologie , Frottis vaginaux/méthodes , Jeune adulte , Dysplasie du col utérin/épidémiologie , Dysplasie du col utérin/génétique , Dysplasie du col utérin/anatomopathologie , Dysplasie du col utérin/virologie
6.
Breast Cancer Res Treat ; 158(3): 441-54, 2016 08.
Article de Anglais | MEDLINE | ID: mdl-27393618

RÉSUMÉ

Estrogen receptor (ER)-negative cancers have a poor prognosis, and few targeted therapies are available for their treatment. Our previous analyses have identified potential kinase targets critical for the growth of ER-negative, progesterone receptor (PR)-negative and HER2-negative, or "triple-negative" breast cancer (TNBC). Because phosphatases regulate the function of kinase signaling pathways, in this study, we investigated whether phosphatases are also differentially expressed in ER-negative compared to those in ER-positive breast cancers. We compared RNA expression in 98 human breast cancers (56 ER-positive and 42 ER-negative) to identify phosphatases differentially expressed in ER-negative compared to those in ER-positive breast cancers. We then examined the effects of one selected phosphatase, dual specificity phosphatase 4 (DUSP4), on proliferation, cell growth, migration and invasion, and on signaling pathways using protein microarray analyses of 172 proteins, including phosphoproteins. We identified 48 phosphatase genes are significantly differentially expressed in ER-negative compared to those in ER-positive breast tumors. We discovered that 31 phosphatases were more highly expressed, while 11 were underexpressed specifically in ER-negative breast cancers. The DUSP4 gene is underexpressed in ER-negative breast cancer and is deleted in approximately 50 % of breast cancers. Induced DUSP4 expression suppresses both in vitro and in vivo growths of breast cancer cells. Our studies show that induced DUSP4 expression blocks the cell cycle at the G1/S checkpoint; inhibits ERK1/2, p38, JNK1, RB, and NFkB p65 phosphorylation; and inhibits invasiveness of TNBC cells. These results suggest that that DUSP4 is a critical regulator of the growth and invasion of triple-negative breast cancer cells.


Sujet(s)
Tumeurs du sein/métabolisme , Dual-specificity phosphatases/génétique , Dual-specificity phosphatases/métabolisme , Mitogen-Activated Protein Kinase Phosphatases/génétique , Mitogen-Activated Protein Kinase Phosphatases/métabolisme , Analyse par réseau de protéines/méthodes , Récepteurs des oestrogènes/métabolisme , Animaux , Tumeurs du sein/génétique , Lignée cellulaire tumorale , Mouvement cellulaire , Prolifération cellulaire , Régulation négative , Femelle , Régulation de l'expression des gènes tumoraux , Humains , Cellules MCF-7 , Souris , Invasion tumorale , Transplantation tumorale , Phosphorylation , Récepteurs des oestrogènes/déficit , Transduction du signal
7.
J Clin Invest ; 125(7): 2707-20, 2015 Jul 01.
Article de Anglais | MEDLINE | ID: mdl-26075823

RÉSUMÉ

Estrogen receptor-negative (ER-negative) breast cancers are extremely aggressive and associated with poor prognosis. In particular, effective treatment strategies are limited for patients diagnosed with triple receptor-negative breast cancer (TNBC), which also carries the worst prognosis of all forms of breast cancer; therefore, extensive studies have focused on the identification of molecularly targeted therapies for this tumor subtype. Here, we sought to identify molecular targets that are capable of suppressing tumorigenesis in TNBCs. Specifically, we found that death-associated protein kinase 1 (DAPK1) is essential for growth of p53-mutant cancers, which account for over 80% of TNBCs. Depletion or inhibition of DAPK1 suppressed growth of p53-mutant but not p53-WT breast cancer cells. Moreover, DAPK1 inhibition limited growth of other p53-mutant cancers, including pancreatic and ovarian cancers. DAPK1 mediated the disruption of the TSC1/TSC2 complex, resulting in activation of the mTOR pathway. Our studies demonstrated that high DAPK1 expression causes increased cancer cell growth and enhanced signaling through the mTOR/S6K pathway; evaluation of multiple breast cancer patient data sets revealed that high DAPK1 expression associates with worse outcomes in individuals with p53-mutant cancers. Together, our data support targeting DAPK1 as a potential therapeutic strategy for p53-mutant cancers.


Sujet(s)
Tumeurs du sein/enzymologie , Tumeurs du sein/génétique , Death-associated protein kinases/physiologie , Gènes p53 , Mutation , Animaux , Tumeurs du sein/thérapie , Lignée cellulaire tumorale , Prolifération cellulaire , Death-associated protein kinases/antagonistes et inhibiteurs , Death-associated protein kinases/génétique , Femelle , Expression des gènes , Techniques de knock-down de gènes , Humains , Souris , Souris nude , Thérapie moléculaire ciblée , Tumeurs de l'ovaire/enzymologie , Tumeurs de l'ovaire/génétique , Tumeurs de l'ovaire/thérapie , Tumeurs du pancréas/enzymologie , Tumeurs du pancréas/génétique , Tumeurs du pancréas/thérapie , ARN messager/génétique , ARN messager/métabolisme , ARN tumoral/génétique , ARN tumoral/métabolisme , Petit ARN interférent/génétique , Récepteurs des oestrogènes/métabolisme , Transduction du signal , Sérine-thréonine kinases TOR/métabolisme , Protéine p53 suppresseur de tumeur/antagonistes et inhibiteurs , Protéine p53 suppresseur de tumeur/génétique , Tests d'activité antitumorale sur modèle de xénogreffe
8.
Clin Cancer Res ; 21(7): 1688-98, 2015 Apr 01.
Article de Anglais | MEDLINE | ID: mdl-25208879

RÉSUMÉ

PURPOSE: Genomic profiling studies suggest that triple-negative breast cancer (TNBC) is a heterogeneous disease. In this study, we sought to define TNBC subtypes and identify subtype-specific markers and targets. EXPERIMENTAL DESIGN: RNA and DNA profiling analyses were conducted on 198 TNBC tumors [estrogen receptor (ER) negativity defined as Allred scale value ≤ 2] with >50% cellularity (discovery set: n = 84; validation set: n = 114) collected at Baylor College of Medicine (Houston, TX). An external dataset of seven publically accessible TNBC studies was used to confirm results. DNA copy number, disease-free survival (DFS), and disease-specific survival (DSS) were analyzed independently using these datasets. RESULTS: We identified and confirmed four distinct TNBC subtypes: (i) luminal androgen receptor (AR; LAR), (ii) mesenchymal (MES), (iii) basal-like immunosuppressed (BLIS), and (iv) basal-like immune-activated (BLIA). Of these, prognosis is worst for BLIS tumors and best for BLIA tumors for both DFS (log-rank test: P = 0.042 and 0.041, respectively) and DSS (log-rank test: P = 0.039 and 0.029, respectively). DNA copy number analysis produced two major groups (LAR and MES/BLIS/BLIA) and suggested that gene amplification drives gene expression in some cases [FGFR2 (BLIS)]. Putative subtype-specific targets were identified: (i) LAR: androgen receptor and the cell surface mucin MUC1, (ii) MES: growth factor receptors [platelet-derived growth factor (PDGF) receptor A; c-Kit], (iii) BLIS: an immunosuppressing molecule (VTCN1), and (iv) BLIA: Stat signal transduction molecules and cytokines. CONCLUSION: There are four stable TNBC subtypes characterized by the expression of distinct molecular profiles that have distinct prognoses. These studies identify novel subtype-specific targets that can be targeted in the future for the effective treatment of TNBCs.


Sujet(s)
Transcriptome , Tumeurs du sein triple-négatives/classification , Tumeurs du sein triple-négatives/génétique , Tumeurs du sein triple-négatives/mortalité , Adulte , Sujet âgé , Femelle , Analyse de profil d'expression de gènes , Humains , Estimation de Kaplan-Meier , Adulte d'âge moyen , Modèles des risques proportionnels
10.
Cancer Res ; 73(11): 3470-80, 2013 Jun 01.
Article de Anglais | MEDLINE | ID: mdl-23633491

RÉSUMÉ

Triple-negative breast cancers (TNBC) are aggressive with no effective targeted therapies. A combined database analysis identified 32 inflammation-related genes differentially expressed in TNBCs and 10 proved critical for anchorage-independent growth. In TNBC cells, an LPA-LPAR2-EZH2 NF-κB signaling cascade was essential for expression of interleukin (IL)-6, IL-8, and CXCL1. Concurrent inhibition of IL-6 and IL-8 expression dramatically inhibited colony formation and cell survival in vitro and stanched tumor engraftment and growth in vivo. A Cox multivariable analysis of patient specimens revealed that IL-6 and IL-8 expression predicted patient survival times. Together these findings offer a rationale for dual inhibition of IL-6/IL-8 signaling as a therapeutic strategy to improve outcomes for patients with TNBCs.


Sujet(s)
Interleukine-6/biosynthèse , Interleukine-8/biosynthèse , Tumeurs du sein triple-négatives/immunologie , Tumeurs du sein triple-négatives/anatomopathologie , Animaux , Apoptose/génétique , Apoptose/immunologie , Lignée cellulaire tumorale , Survie cellulaire/immunologie , Cytokines , Femelle , Hétérogreffes , Humains , Interleukine-6/antagonistes et inhibiteurs , Interleukine-6/génétique , Interleukine-8/antagonistes et inhibiteurs , Interleukine-8/génétique , Souris , Souris nude , Cellules souches tumorales/immunologie , Cellules souches tumorales/anatomopathologie , Modèles des risques proportionnels , Transduction du signal , Transfection , Tumeurs du sein triple-négatives/génétique
11.
Cancer Res ; 72(11): 2728-37, 2012 Jun 01.
Article de Anglais | MEDLINE | ID: mdl-22507853

RÉSUMÉ

Panels of prognostic biomarkers selected using candidate approaches often do not validate in independent populations, so additional strategies are needed to identify reliable classifiers. In this study, we used an array-based approach to measure DNA methylation and applied a novel method for grouping CpG dinucleotides according to well-characterized genomic sequence features. A hypermethylation profile among 13 CpG loci, characterized by polycomb group target genes, mammalian interspersed repeats, and transcription factor-binding sites (PcG/MIR/TFBS), was associated with reduced survival (HR, 3.98; P = 0.001) in patients with head and neck squamous cell carcinoma. This association was driven by CpGs associated with the TAP1 and ALDH3A1 genes, findings that were validated in an independent patient group (HR, 2.86; P = 0.04). Together, the data not only elucidate new potential targets for therapeutic intervention in head and neck cancer but also may aid in the identification of poor prognosis patients who may require more aggressive treatment regimens.


Sujet(s)
Carcinome épidermoïde/génétique , Méthylation de l'ADN , Épigenèse génétique , Tumeurs de la tête et du cou/génétique , Membre-2 de la sous-famille B à cassette de liaison à l'ATP , Transporteurs ABC/génétique , Aldehyde dehydrogenase/génétique , Carcinome épidermoïde/traitement médicamenteux , Carcinome épidermoïde/mortalité , Carcinome épidermoïde/anatomopathologie , Biologie informatique , Ilots CpG , Tumeurs de la tête et du cou/traitement médicamenteux , Tumeurs de la tête et du cou/mortalité , Tumeurs de la tête et du cou/anatomopathologie , Humains , Pronostic , Modèles des risques proportionnels , Carcinome épidermoïde de la tête et du cou
12.
Environ Health Perspect ; 120(2): 296-302, 2012 Feb.
Article de Anglais | MEDLINE | ID: mdl-22005006

RÉSUMÉ

BACKGROUND: Fetal programming describes the theory linking environmental conditions during embryonic and fetal development with risk of diseases later in life. Environmental insults in utero may lead to changes in epigenetic mechanisms potentially affecting fetal development. OBJECTIVES: We examined associations between in utero exposures, infant growth, and methylation of repetitive elements and gene-associated DNA in human term placenta tissue samples. METHODS: Placental tissues and associated demographic and clinical data were obtained from subjects delivering at Women and Infants Hospital in Providence, Rhode Island (USA). Methylation levels of long interspersed nuclear element-1 (LINE-1) and the Alu element AluYb8 were determined in 380 placental samples from term deliveries using bisulfite pyrosequencing. Genomewide DNA methylation profiles were obtained in a subset of 184 samples using the Illumina Infinium HumanMethylation27 BeadArray. Multiple linear regression, model-based clustering methods, and gene set enrichment analysis examined the association between birth weight percentile, demographic variables, and repetitive element methylation and gene-associated CpG locus methylation. RESULTS: LINE-1 and AluYb8 methylation levels were found to be significantly positively associated with birth weight percentile (p = 0.01 and p < 0.0001, respectively) and were found to differ significantly among infants exposed to tobacco smoke and alcohol. Increased placental AluYb8 methylation was positively associated with average methylation among CpG loci found in polycomb group target genes; developmentally related transcription factor binding sites were overrepresented for differentially methylated loci associated with both elements. CONCLUSIONS: Our results suggest that repetitive element methylation markers, most notably AluYb8 methylation, may be susceptible to epigenetic alterations resulting from the intrauterine environment and play a critical role in mediating placenta function, and may ultimately inform on the developmental basis of health and disease.


Sujet(s)
Méthylation de l'ADN , Nouveau-né/croissance et développement , Exposition maternelle , Effets différés de l'exposition prénatale à des facteurs de risque/épidémiologie , Adulte , Consommation d'alcool/effets indésirables , Séquences Alu , Poids de naissance , Villes/épidémiologie , Analyse de regroupements , Ilots CpG , Épigenèse génétique , Femelle , Humains , Nouveau-né/métabolisme , Nourrisson petit pour son âge gestationnel/croissance et développement , Nourrisson petit pour son âge gestationnel/métabolisme , Modèles linéaires , Éléments LINE , Placenta/métabolisme , Grossesse , Effets différés de l'exposition prénatale à des facteurs de risque/génétique , Rhode Island/épidémiologie , Analyse de séquence d'ADN , Pollution par la fumée de tabac/effets indésirables , Jeune adulte
13.
Clin Cancer Res ; 17(11): 3579-89, 2011 Jun 01.
Article de Anglais | MEDLINE | ID: mdl-21505061

RÉSUMÉ

PURPOSE: The human epigenome is profoundly altered in cancers, with a characteristic loss of methylation in repetitive regions and concomitant accumulation of gene promoter methylation. The degree to which these processes are coordinated is unclear so we investigated both in head and neck squamous cell carcinomas. EXPERIMENTAL DESIGN: Global methylation was measured using the luminometric methylation assay (LUMA) and pyrosequencing of LINE-1Hs and AluYb8 repetitive elements in a series of 138 tumors. We also measured methylation of more than 27,000 CpG loci with the Illumina HumanMethylation27 Microarray (n = 91). RESULTS: LINE-1 methylation was significantly associated with LUMA and Infinium loci methylation (Spearman's ρ = 0.52/ρ = 0.56, both P < 0.001) but not that of AluYb8. Methylation of LINE-1, AluYb8, and Infinium loci differed by tumor site (each Kruskal-Wallis, P < 0.05). Also, LINE-1 and LUMA methylation were associated with HPV16 E6 serology (each Mann-Whitney, P < 0.05). Comparing LINE-1 methylation to gene-associated methylation, we identified a distinct subset of CpG loci with significant hypermethylation associated with LINE-1 hypomethylation. An investigation of sequence features for these CpG loci revealed that they were significantly less likely to reside in repetitive elements (Gene Set Enrichment Analysis, P < 0.02), enriched in CpG islands (P < 0.001) and were proximal to transcription factor-binding sites (P < 0.05). We validated the top CpG loci that had significant hypermethylation associated with LINE-1 hypomethylation (at EVI2A, IFRD1, KLHL6, and PTPRCAP) by pyrosequencing independent tumors. CONCLUSIONS: These data indicate that global hypomethylation and gene-specific methylation processes are associated in a sequence-dependent manner, and that clinical characteristics and exposures leading to HNSCC may be influencing these processes.


Sujet(s)
Carcinome épidermoïde/métabolisme , Méthylation de l'ADN , Tumeurs de la tête et du cou/métabolisme , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Marqueurs biologiques tumoraux/génétique , Marqueurs biologiques tumoraux/métabolisme , Carcinome épidermoïde/génétique , Carcinome épidermoïde/anatomopathologie , Ilots CpG , Femelle , Tumeurs de la tête et du cou/génétique , Tumeurs de la tête et du cou/anatomopathologie , Humains , Mâle , Adulte d'âge moyen , Régions promotrices (génétique) , Analyse de séquence d'ADN , Cellules cancéreuses en culture
14.
Cancer Res ; 70(14): 5686-94, 2010 Jul 15.
Article de Anglais | MEDLINE | ID: mdl-20587528

RÉSUMÉ

Development of mesothelioma is linked mainly to asbestos exposure, but the combined contributions of genetic and epigenetic alterations are unclear. We investigated the potential relationships between gene copy number (CN) alterations and DNA methylation profiles in a case series of pleural mesotheliomas (n = 23). There were no instances of significantly correlated CN alteration and methylation at probed loci, whereas averaging loci over their associated genes revealed only two genes with significantly correlated CN and methylation alterations. In contrast to the lack of discrete correlations, the overall extent of tumor CN alteration was significantly associated with DNA methylation profile when comparing CN alteration extent among methylation profile classes. Further, there was evidence that this association was partially attributable to prevalent allele loss at the DNA methyltransferase gene DNMT1. Our findings define a strong association between global genetic and global epigenetic dysregulation in mesothelioma, rather than a discrete, local coordination of gene inactivation.


Sujet(s)
Mésothéliome/génétique , Tumeurs de la plèvre/génétique , Allèles , DNA (Cytosine-5-)-methyltransferase 1 , DNA (cytosine-5-)-methyltransferase/génétique , Méthylation de l'ADN , Épigenèse génétique , Dosage génique , Analyse de profil d'expression de gènes , Humains , Mésothéliome/enzymologie , Projets pilotes , Tumeurs de la plèvre/enzymologie , Polymorphisme de nucléotide simple
15.
PLoS One ; 5(3): e9651, 2010 Mar 11.
Article de Anglais | MEDLINE | ID: mdl-20300172

RÉSUMÉ

BACKGROUND: Solid tumors, including head and neck squamous cell carcinomas (HNSCC), arise as a result of genetic and epigenetic alterations in a sustained stress environment. Little work has been done that simultaneously examines the spectrum of both types of changes in human tumors on a genome-wide scale and results so far have been limited and mixed. Since it has been hypothesized that epigenetic alterations may act by providing the second carcinogenic hit in gene silencing, we sought to identify genome-wide DNA copy number alterations and CpG dinucleotide methylation events and examine the global/local relationships between these types of alterations in HNSCC. METHODOLOGY/PRINCIPAL FINDINGS: We have extended a prior analysis of 1,413 cancer-associated loci for epigenetic changes in HNSCC by integrating DNA copy number alterations, measured at 500,000 polymorphic loci, in a case series of 19 primary HNSCC tumors. We have previously demonstrated that local copy number does not bias methylation measurements in this array platform. Importantly, we found that the global pattern of copy number alterations in these tumors was significantly associated with tumor methylation profiles (p<0.002). However at the local level, gene promoter regions did not exhibit a correlation between copy number and methylation (lowest q = 0.3), and the spectrum of genes affected by each type of alteration was unique. CONCLUSION/SIGNIFICANCE: This work, using a novel and robust statistical approach demonstrates that, although a "second hit" mechanism is not likely the predominant mode of action for epigenetic dysregulation in cancer, the patterns of methylation events are associated with the patterns of allele loss. Our work further highlights the utility of integrative genomics approaches in exploring the driving somatic alterations in solid tumors.


Sujet(s)
Carcinome épidermoïde/génétique , Épigenèse génétique , Régulation de l'expression des gènes tumoraux , Tumeurs de la tête et du cou/génétique , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Ilots CpG , Méthylation de l'ADN , Femelle , Extinction de l'expression des gènes , Humains , Mâle , Adulte d'âge moyen , Modèles génétiques , Régions promotrices (génétique)
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