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de Santiago I, Liu W, Yuan K, O'Reilly M, Chilamakuri CSR, Ponder BAJ, Meyer KB, Markowetz F. BaalChIP: Bayesian analysis of allele-specific transcription factor binding in cancer genomes. Genome Biol 2017; 18:39. [PMID: 28235418 PMCID: PMC5326502 DOI: 10.1186/s13059-017-1165-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 02/01/2017] [Indexed: 02/07/2023] Open
Abstract
Allele-specific measurements of transcription factor binding from ChIP-seq data are key to dissecting the allelic effects of non-coding variants and their contribution to phenotypic diversity. However, most methods of detecting an allelic imbalance assume diploid genomes. This assumption severely limits their applicability to cancer samples with frequent DNA copy-number changes. Here we present a Bayesian statistical approach called BaalChIP to correct for the effect of background allele frequency on the observed ChIP-seq read counts. BaalChIP allows the joint analysis of multiple ChIP-seq samples across a single variant and outperforms competing approaches in simulations. Using 548 ENCODE ChIP-seq and six targeted FAIRE-seq samples, we show that BaalChIP effectively corrects allele-specific analysis for copy-number variation and increases the power to detect putative cis-acting regulatory variants in cancer genomes.
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Campbell TM, Castro MAA, Ponder BAJ, Meyer KB. Identification of Post-Transcriptional Modulators of Breast Cancer Transcription Factor Activity Using MINDy. PLoS One 2016; 11:e0168770. [PMID: 27997592 PMCID: PMC5173250 DOI: 10.1371/journal.pone.0168770] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 12/06/2016] [Indexed: 01/08/2023] Open
Abstract
We have recently identified transcription factors (TFs) that are key drivers of breast cancer risk. To better understand the pathways or sub-networks in which these TFs mediate their function we sought to identify upstream modulators of their activity. We applied the MINDy (Modulator Inference by Network Dynamics) algorithm to four TFs (ESR1, FOXA1, GATA3 and SPDEF) that are key drivers of estrogen receptor-positive (ER+) breast cancer risk, as well as cancer progression. Our computational analysis identified over 500 potential modulators. We assayed 189 of these and identified 55 genes with functional characteristics that were consistent with a role as TF modulators. In the future, the identified modulators may be tested as potential therapeutic targets, able to alter the activity of TFs that are critical in the development of breast cancer.
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Campbell TM, Castro MA, de Santiago I, Fletcher MN, Halim S, Prathalingam R, Ponder BA, Meyer KB. FGFR2 risk SNPs confer breast cancer risk by augmenting oestrogen responsiveness. Carcinogenesis 2016; 37:741-750. [PMID: 27236187 PMCID: PMC4967216 DOI: 10.1093/carcin/bgw065] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 05/03/2016] [Accepted: 05/21/2016] [Indexed: 12/11/2022] Open
Abstract
The fibroblast growth factor receptor 2 (FGFR2) locus is consistently the top hit in genome-wide association studies for oestrogen receptor-positive (ER(+)) breast cancer. Yet, its mode of action continues to be controversial. Here, we employ a systems biology approach to demonstrate that signalling via FGFR2 counteracts cell activation by oestrogen. In the presence of oestrogen, the oestrogen receptor (ESR1) regulon (set of ESR1 target genes) is in an active state. However, signalling by FGFR2 is able to reverse the activity of the ESR1 regulon. This effect is seen in multiple distinct FGFR2 signalling model systems, across multiple cells lines and is dependent on the presence of FGFR2. Increased oestrogen exposure has long been associated with an increased risk of breast cancer. We therefore hypothesized that risk variants should reduce FGFR2 expression and subsequent signalling. Indeed, transient transfection experiments assaying the three independent variants of the FGFR2 risk locus (rs2981578, rs35054928 and rs45631563) in their normal chromosomal context show that these single-nucleotide polymorphisms (SNPs) map to transcriptional silencer elements and that, compared with wild type, the risk alleles augment silencer activity. The presence of risk variants results in lower FGFR2 expression and increased oestrogen responsiveness. We thus propose a molecular mechanism by which FGFR2 can confer increased breast cancer risk that is consistent with oestrogen exposure as a major driver of breast cancer risk. Our findings may have implications for the clinical use of FGFR2 inhibitors.
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French JD, Johnatty SE, Lu Y, Beesley J, Gao B, Kalimutho M, Henderson MJ, Russell AJ, Kar S, Chen X, Hillman KM, Kaufmann S, Sivakumaran H, O'Reilly M, Wang C, Korbie DJ, Lambrechts D, Despierre E, Van Nieuwenhuysen E, Lambrechts S, Vergote I, Karlan B, Lester J, Orsulic S, Walsh C, Fasching PA, Beckmann MW, Ekici AB, Hein A, Matsuo K, Hosono S, Pisterer J, Hillemanns P, Nakanishi T, Yatabe Y, Goodman MT, Lurie G, Matsuno RK, Thompson PJ, Pejovic T, Bean Y, Heitz F, Harter P, du Bois A, Schwaab I, Hogdall E, Kjaer SK, Jensen A, Hogdall C, Lundvall L, Engelholm SA, Brown B, Flanagan JM, Metcalf MD, Siddiqui N, Sellers T, Fridley B, Cunningham J, Schildkraut JM, Iversen E, Weber RP, Brennan D, Berchuck A, Pharoah P, Harnett P, Norris MD, Haber M, Goode EL, Lee JS, Khanna KK, Meyer KB, Chenevix-Trench G, deFazio A, Edwards SL, MacGregor S. Germline polymorphisms in an enhancer of PSIP1 are associated with progression-free survival in epithelial ovarian cancer. Oncotarget 2016; 7:6353-68. [PMID: 26840454 PMCID: PMC4872719 DOI: 10.18632/oncotarget.7047] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 01/21/2016] [Indexed: 11/25/2022] Open
Abstract
Women with epithelial ovarian cancer (EOC) are usually treated with platinum/taxane therapy after cytoreductive surgery but there is considerable inter-individual variation in response. To identify germline single-nucleotide polymorphisms (SNPs) that contribute to variations in individual responses to chemotherapy, we carried out a multi-phase genome-wide association study (GWAS) in 1,244 women diagnosed with serous EOC who were treated with the same first-line chemotherapy, carboplatin and paclitaxel. We identified two SNPs (rs7874043 and rs72700653) in TTC39B (best P=7x10-5, HR=1.90, for rs7874043) associated with progression-free survival (PFS). Functional analyses show that both SNPs lie in a putative regulatory element (PRE) that physically interacts with the promoters of PSIP1, CCDC171 and an alternative promoter of TTC39B. The C allele of rs7874043 is associated with poor PFS and showed increased binding of the Sp1 transcription factor, which is critical for chromatin interactions with PSIP1. Silencing of PSIP1 significantly impaired DNA damage-induced Rad51 nuclear foci and reduced cell viability in ovarian cancer lines. PSIP1 (PC4 and SFRS1 Interacting Protein 1) is known to protect cells from stress-induced apoptosis, and high expression is associated with poor PFS in EOC patients. We therefore suggest that the minor allele of rs7874043 confers poor PFS by increasing PSIP1 expression.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Apoptosis
- Biomarkers, Tumor/genetics
- Cell Proliferation
- Chromatin Immunoprecipitation
- Cohort Studies
- Cystadenocarcinoma, Serous/drug therapy
- Cystadenocarcinoma, Serous/genetics
- Cystadenocarcinoma, Serous/mortality
- Cystadenocarcinoma, Serous/pathology
- Electrophoretic Mobility Shift Assay
- Enhancer Elements, Genetic/genetics
- Fallopian Tube Neoplasms/drug therapy
- Fallopian Tube Neoplasms/genetics
- Fallopian Tube Neoplasms/mortality
- Fallopian Tube Neoplasms/pathology
- Female
- Follow-Up Studies
- Germ-Line Mutation/genetics
- Humans
- Ovarian Neoplasms/drug therapy
- Ovarian Neoplasms/genetics
- Ovarian Neoplasms/mortality
- Ovarian Neoplasms/pathology
- Peritoneal Neoplasms/drug therapy
- Peritoneal Neoplasms/genetics
- Peritoneal Neoplasms/mortality
- Peritoneal Neoplasms/pathology
- Polymorphism, Single Nucleotide/genetics
- Prognosis
- RNA, Messenger/genetics
- Real-Time Polymerase Chain Reaction
- Reverse Transcriptase Polymerase Chain Reaction
- Survival Rate
- Transcription Factors/genetics
- Tumor Cells, Cultured
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Castro MAA, de Santiago I, Campbell TM, Vaughn C, Hickey TE, Ross E, Tilley WD, Markowetz F, Ponder BAJ, Meyer KB. Regulators of genetic risk of breast cancer identified by integrative network analysis. Nat Genet 2016; 48:12-21. [PMID: 26618344 PMCID: PMC4697365 DOI: 10.1038/ng.3458] [Citation(s) in RCA: 131] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 11/06/2015] [Indexed: 12/14/2022]
Abstract
Genetic risk for breast cancer is conferred by a combination of multiple variants of small effect. To better understand how risk loci might combine, we examined whether risk-associated genes share regulatory mechanisms. We created a breast cancer gene regulatory network comprising transcription factors and groups of putative target genes (regulons) and asked whether specific regulons are enriched for genes associated with risk loci via expression quantitative trait loci (eQTLs). We identified 36 overlapping regulons that were enriched for risk loci and formed a distinct cluster within the network, suggesting shared biology. The risk transcription factors driving these regulons are frequently mutated in cancer and lie in two opposing subgroups, which relate to estrogen receptor (ER)(+) luminal A or luminal B and ER(-) basal-like cancers and to different luminal epithelial cell populations in the adult mammary gland. Our network approach provides a foundation for determining the regulatory circuits governing breast cancer, to identify targets for intervention, and is transferable to other disease settings.
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Glubb DM, Maranian MJ, Michailidou K, Pooley KA, Meyer KB, Kar S, Carlebur S, O'Reilly M, Betts JA, Hillman KM, Kaufmann S, Beesley J, Canisius S, Hopper JL, Southey MC, Tsimiklis H, Apicella C, Schmidt MK, Broeks A, Hogervorst FB, van der Schoot CE, Muir K, Lophatananon A, Stewart-Brown S, Siriwanarangsan P, Fasching PA, Ruebner M, Ekici AB, Beckmann MW, Peto J, dos-Santos-Silva I, Fletcher O, Johnson N, Pharoah PDP, Bolla MK, Wang Q, Dennis J, Sawyer EJ, Tomlinson I, Kerin MJ, Miller N, Burwinkel B, Marme F, Yang R, Surowy H, Guénel P, Truong T, Menegaux F, Sanchez M, Bojesen SE, Nordestgaard BG, Nielsen SF, Flyger H, González-Neira A, Benitez J, Zamora MP, Arias Perez JI, Anton-Culver H, Neuhausen SL, Brenner H, Dieffenbach AK, Arndt V, Stegmaier C, Meindl A, Schmutzler RK, Brauch H, Ko YD, Brüning T, Nevanlinna H, Muranen TA, Aittomäki K, Blomqvist C, Matsuo K, Ito H, Iwata H, Tanaka H, Dörk T, Bogdanova NV, Helbig S, Lindblom A, Margolin S, Mannermaa A, Kataja V, Kosma VM, Hartikainen JM, Wu AH, Tseng CC, Van Den Berg D, Stram DO, Lambrechts D, Zhao H, Weltens C, van Limbergen E, Chang-Claude J, Flesch-Janys D, Rudolph A, Seibold P, Radice P, Peterlongo P, Barile M, Capra F, Couch FJ, Olson JE, Hallberg E, Vachon C, Giles GG, Milne RL, McLean C, Haiman CA, Henderson BE, Schumacher F, Le Marchand L, Simard J, Goldberg MS, Labrèche F, Dumont M, Teo SH, Yip CH, See MH, Cornes B, Cheng CY, Ikram MK, Kristensen V, Zheng W, Halverson SL, Shrubsole M, Long J, Winqvist R, Pylkäs K, Jukkola-Vuorinen A, Kauppila S, Andrulis IL, Knight JA, Glendon G, Tchatchou S, Devilee P, Tollenaar RAEM, Seynaeve C, Van Asperen CJ, García-Closas M, Figueroa J, Chanock SJ, Lissowska J, Czene K, Klevebring D, Darabi H, Eriksson M, Hooning MJ, Hollestelle A, Martens JWM, Collée JM, Hall P, Li J, Humphreys K, Shu XO, Lu W, Gao YT, Cai H, Cox A, Cross SS, Reed MWR, Blot W, Signorello LB, Cai Q, Shah M, Ghoussaini M, Kang D, Choi JY, Park SK, Noh DY, Hartman M, Miao H, Lim WY, Tang A, Hamann U, Torres D, Jakubowska A, Lubinski J, Jaworska K, Durda K, Sangrajrang S, Gaborieau V, Brennan P, McKay J, Olswold C, Slager S, Toland AE, Yannoukakos D, Shen CY, Wu PE, Yu JC, Hou MF, Swerdlow A, Ashworth A, Orr N, Jones M, Pita G, Alonso MR, Álvarez N, Herrero D, Tessier DC, Vincent D, Bacot F, Luccarini C, Baynes C, Ahmed S, Healey CS, Brown MA, Ponder BAJ, Chenevix-Trench G, Thompson DJ, Edwards SL, Easton DF, Dunning AM, French JD. Fine-scale mapping of the 5q11.2 breast cancer locus reveals at least three independent risk variants regulating MAP3K1. Am J Hum Genet 2015; 96:5-20. [PMID: 25529635 PMCID: PMC4289692 DOI: 10.1016/j.ajhg.2014.11.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 11/17/2014] [Indexed: 01/04/2023] Open
Abstract
Genome-wide association studies (GWASs) have revealed SNP rs889312 on 5q11.2 to be associated with breast cancer risk in women of European ancestry. In an attempt to identify the biologically relevant variants, we analyzed 909 genetic variants across 5q11.2 in 103,991 breast cancer individuals and control individuals from 52 studies in the Breast Cancer Association Consortium. Multiple logistic regression analyses identified three independent risk signals: the strongest associations were with 15 correlated variants (iCHAV1), where the minor allele of the best candidate, rs62355902, associated with significantly increased risks of both estrogen-receptor-positive (ER(+): odds ratio [OR] = 1.24, 95% confidence interval [CI] = 1.21-1.27, ptrend = 5.7 × 10(-44)) and estrogen-receptor-negative (ER(-): OR = 1.10, 95% CI = 1.05-1.15, ptrend = 3.0 × 10(-4)) tumors. After adjustment for rs62355902, we found evidence of association of a further 173 variants (iCHAV2) containing three subsets with a range of effects (the strongest was rs113317823 [pcond = 1.61 × 10(-5)]) and five variants composing iCHAV3 (lead rs11949391; ER(+): OR = 0.90, 95% CI = 0.87-0.93, pcond = 1.4 × 10(-4)). Twenty-six percent of the prioritized candidate variants coincided with four putative regulatory elements that interact with the MAP3K1 promoter through chromatin looping and affect MAP3K1 promoter activity. Functional analysis indicated that the cancer risk alleles of four candidates (rs74345699 and rs62355900 [iCHAV1], rs16886397 [iCHAV2a], and rs17432750 [iCHAV3]) increased MAP3K1 transcriptional activity. Chromatin immunoprecipitation analysis revealed diminished GATA3 binding to the minor (cancer-protective) allele of rs17432750, indicating a mechanism for its action. We propose that the cancer risk alleles act to increase MAP3K1 expression in vivo and might promote breast cancer cell survival.
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Agarwal D, Pineda S, Michailidou K, Herranz J, Pita G, Moreno LT, Alonso MR, Dennis J, Wang Q, Bolla MK, Meyer KB, Menéndez-Rodríguez P, Hardisson D, Mendiola M, González-Neira A, Lindblom A, Margolin S, Swerdlow A, Ashworth A, Orr N, Jones M, Matsuo K, Ito H, Iwata H, Kondo N, Hartman M, Hui M, Lim WY, T-C Iau P, Sawyer E, Tomlinson I, Kerin M, Miller N, Kang D, Choi JY, Park SK, Noh DY, Hopper JL, Schmidt DF, Makalic E, Southey MC, Teo SH, Yip CH, Sivanandan K, Tay WT, Brauch H, Brüning T, Hamann U, Dunning AM, Shah M, Andrulis IL, Knight JA, Glendon G, Tchatchou S, Schmidt MK, Broeks A, Rosenberg EH, van't Veer LJ, Fasching PA, Renner SP, Ekici AB, Beckmann MW, Shen CY, Hsiung CN, Yu JC, Hou MF, Blot W, Cai Q, Wu AH, Tseng CC, Van Den Berg D, Stram DO, Cox A, Brock IW, Reed MWR, Muir K, Lophatananon A, Stewart-Brown S, Siriwanarangsan P, Zheng W, Deming-Halverson S, Shrubsole MJ, Long J, Shu XO, Lu W, Gao YT, Zhang B, Radice P, Peterlongo P, Manoukian S, Mariette F, Sangrajrang S, McKay J, Couch FJ, Toland AE, Yannoukakos D, Fletcher O, Johnson N, Silva IDS, Peto J, Marme F, Burwinkel B, Guénel P, Truong T, Sanchez M, Mulot C, Bojesen SE, Nordestgaard BG, Flyer H, Brenner H, Dieffenbach AK, Arndt V, Stegmaier C, Mannermaa A, Kataja V, Kosma VM, Hartikainen JM, Lambrechts D, Yesilyurt BT, Floris G, Leunen K, Chang-Claude J, Rudolph A, Seibold P, Flesch-Janys D, Wang X, Olson JE, Vachon C, Purrington K, Giles GG, Severi G, Baglietto L, Haiman CA, Henderson BE, Schumacher F, Le Marchand L, Simard J, Dumont M, Goldberg MS, Labrèche F, Winqvist R, Pylkäs K, Jukkola-Vuorinen A, Grip M, Devilee P, Tollenaar RAEM, Seynaeve C, García-Closas M, Chanock SJ, Lissowska J, Figueroa JD, Czene K, Eriksson M, Humphreys K, Darabi H, Hooning MJ, Kriege M, Collée JM, Tilanus-Linthorst M, Li J, Jakubowska A, Lubinski J, Jaworska-Bieniek K, Durda K, Nevanlinna H, Muranen TA, Aittomäki K, Blomqvist C, Bogdanova N, Dörk T, Hall P, Chenevix-Trench G, Easton DF, Pharoah PDP, Arias-Perez JI, Zamora P, Benítez J, Milne RL. FGF receptor genes and breast cancer susceptibility: results from the Breast Cancer Association Consortium. Br J Cancer 2014; 110:1088-100. [PMID: 24548884 PMCID: PMC3929867 DOI: 10.1038/bjc.2013.769] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 11/08/2013] [Accepted: 11/15/2013] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Breast cancer is one of the most common malignancies in women. Genome-wide association studies have identified FGFR2 as a breast cancer susceptibility gene. Common variation in other fibroblast growth factor (FGF) receptors might also modify risk. We tested this hypothesis by studying genotyped single-nucleotide polymorphisms (SNPs) and imputed SNPs in FGFR1, FGFR3, FGFR4 and FGFRL1 in the Breast Cancer Association Consortium. METHODS Data were combined from 49 studies, including 53 835 cases and 50 156 controls, of which 89 050 (46 450 cases and 42 600 controls) were of European ancestry, 12 893 (6269 cases and 6624 controls) of Asian and 2048 (1116 cases and 932 controls) of African ancestry. Associations with risk of breast cancer, overall and by disease sub-type, were assessed using unconditional logistic regression. RESULTS Little evidence of association with breast cancer risk was observed for SNPs in the FGF receptor genes. The strongest evidence in European women was for rs743682 in FGFR3; the estimated per-allele odds ratio was 1.05 (95% confidence interval=1.02-1.09, P=0.0020), which is substantially lower than that observed for SNPs in FGFR2. CONCLUSION Our results suggest that common variants in the other FGF receptors are not associated with risk of breast cancer to the degree observed for FGFR2.
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MESH Headings
- Breast Neoplasms/genetics
- Case-Control Studies
- Female
- Genetic Predisposition to Disease
- Genetic Variation
- Genome-Wide Association Study
- Genotype
- Humans
- Polymorphism, Single Nucleotide/genetics
- Receptor, Fibroblast Growth Factor, Type 1/genetics
- Receptor, Fibroblast Growth Factor, Type 2/genetics
- Receptor, Fibroblast Growth Factor, Type 3/genetics
- Receptor, Fibroblast Growth Factor, Type 4/genetics
- Receptor, Fibroblast Growth Factor, Type 5/genetics
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Meyer KB, O'Reilly M, Michailidou K, Carlebur S, Edwards SL, French JD, Prathalingham R, Dennis J, Bolla MK, Wang Q, de Santiago I, Hopper JL, Tsimiklis H, Apicella C, Southey MC, Schmidt MK, Broeks A, Van 't Veer LJ, Hogervorst FB, Muir K, Lophatananon A, Stewart-Brown S, Siriwanarangsan P, Fasching PA, Lux MP, Ekici AB, Beckmann MW, Peto J, Dos Santos Silva I, Fletcher O, Johnson N, Sawyer EJ, Tomlinson I, Kerin MJ, Miller N, Marme F, Schneeweiss A, Sohn C, Burwinkel B, Guénel P, Truong T, Laurent-Puig P, Menegaux F, Bojesen SE, Nordestgaard BG, Nielsen SF, Flyger H, Milne RL, Zamora MP, Arias JI, Benitez J, Neuhausen S, Anton-Culver H, Ziogas A, Dur CC, Brenner H, Müller H, Arndt V, Stegmaier C, Meindl A, Schmutzler RK, Engel C, Ditsch N, Brauch H, Brüning T, Ko YD, Nevanlinna H, Muranen TA, Aittomäki K, Blomqvist C, Matsuo K, Ito H, Iwata H, Yatabe Y, Dörk T, Helbig S, Bogdanova NV, Lindblom A, Margolin S, Mannermaa A, Kataja V, Kosma VM, Hartikainen JM, Chenevix-Trench G, Wu AH, Tseng CC, Van Den Berg D, Stram DO, Lambrechts D, Thienpont B, Christiaens MR, Smeets A, Chang-Claude J, Rudolph A, Seibold P, Flesch-Janys D, Radice P, Peterlongo P, Bonanni B, Bernard L, Couch FJ, Olson JE, Wang X, Purrington K, Giles GG, Severi G, Baglietto L, McLean C, Haiman CA, Henderson BE, Schumacher F, Le Marchand L, Simard J, Goldberg MS, Labrèche F, Dumont M, Teo SH, Yip CH, Phuah SY, Kristensen V, Grenaker Alnæs G, Børresen-Dale AL, Zheng W, Deming-Halverson S, Shrubsole M, Long J, Winqvist R, Pylkäs K, Jukkola-Vuorinen A, Kauppila S, Andrulis IL, Knight JA, Glendon G, Tchatchou S, Devilee P, Tollenaar RAEM, Seynaeve CM, García-Closas M, Figueroa J, Chanock SJ, Lissowska J, Czene K, Darabi H, Eriksson K, Hooning MJ, Martens JWM, van den Ouweland AMW, van Deurzen CHM, Hall P, Li J, Liu J, Humphreys K, Shu XO, Lu W, Gao YT, Cai H, Cox A, Reed MWR, Blot W, Signorello LB, Cai Q, Pharoah PDP, Ghoussaini M, Harrington P, Tyrer J, Kang D, Choi JY, Park SK, Noh DY, Hartman M, Hui M, Lim WY, Buhari SA, Hamann U, Försti A, Rüdiger T, Ulmer HU, Jakubowska A, Lubinski J, Jaworska K, Durda K, Sangrajrang S, Gaborieau V, Brennan P, McKay J, Vachon C, Slager S, Fostira F, Pilarski R, Shen CY, Hsiung CN, Wu PE, Hou MF, Swerdlow A, Ashworth A, Orr N, Schoemaker MJ, Ponder BAJ, Dunning AM, Easton DF. Fine-scale mapping of the FGFR2 breast cancer risk locus: putative functional variants differentially bind FOXA1 and E2F1. Am J Hum Genet 2013; 93:1046-60. [PMID: 24290378 PMCID: PMC3852923 DOI: 10.1016/j.ajhg.2013.10.026] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 10/15/2013] [Accepted: 10/28/2013] [Indexed: 12/19/2022] Open
Abstract
The 10q26 locus in the second intron of FGFR2 is the locus most strongly associated with estrogen-receptor-positive breast cancer in genome-wide association studies. We conducted fine-scale mapping in case-control studies genotyped with a custom chip (iCOGS), comprising 41 studies (n = 89,050) of European ancestry, 9 Asian ancestry studies (n = 13,983), and 2 African ancestry studies (n = 2,028) from the Breast Cancer Association Consortium. We identified three statistically independent risk signals within the locus. Within risk signals 1 and 3, genetic analysis identified five and two variants, respectively, highly correlated with the most strongly associated SNPs. By using a combination of genetic fine mapping, data on DNase hypersensitivity, and electrophoretic mobility shift assays to study protein-DNA binding, we identified rs35054928, rs2981578, and rs45631563 as putative functional SNPs. Chromatin immunoprecipitation showed that FOXA1 preferentially bound to the risk-associated allele (C) of rs2981578 and was able to recruit ERα to this site in an allele-specific manner, whereas E2F1 preferentially bound the risk variant of rs35054928. The risk alleles were preferentially found in open chromatin and bound by Ser5 phosphorylated RNA polymerase II, suggesting that the risk alleles are associated with changes in transcription. Chromatin conformation capture demonstrated that the risk region was able to interact with the promoter of FGFR2, the likely target gene of this risk region. A role for FOXA1 in mediating breast cancer susceptibility at this locus is consistent with the finding that the FGFR2 risk locus primarily predisposes to estrogen-receptor-positive disease.
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Abstract
Many SNPs associated with human disease are located in non-coding regions of the genome. A new study shows that SNPs associated with breast cancer risk are located in enhancer regions and alter binding affinity for the pioneer factor FOXA1.
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Fletcher MNC, Castro MAA, Wang X, de Santiago I, O’Reilly M, Chin SF, Rueda OM, Caldas C, Ponder BAJ, Markowetz F, Meyer KB. Master regulators of FGFR2 signalling and breast cancer risk. Nat Commun 2013; 4:2464. [PMID: 24043118 PMCID: PMC3778544 DOI: 10.1038/ncomms3464] [Citation(s) in RCA: 153] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 08/16/2013] [Indexed: 01/14/2023] Open
Abstract
The fibroblast growth factor receptor 2 (FGFR2) locus has been consistently identified as a breast cancer risk locus in independent genome-wide association studies. However, the molecular mechanisms underlying FGFR2-mediated risk are still unknown. Using model systems we show that FGFR2-regulated genes are preferentially linked to breast cancer risk loci in expression quantitative trait loci analysis, supporting the concept that risk genes cluster in pathways. Using a network derived from 2,000 transcriptional profiles we identify SPDEF, ERα, FOXA1, GATA3 and PTTG1 as master regulators of fibroblast growth factor receptor 2 signalling, and show that ERα occupancy responds to fibroblast growth factor receptor 2 signalling. Our results indicate that ERα, FOXA1 and GATA3 contribute to the regulation of breast cancer susceptibility genes, which is consistent with the effects of anti-oestrogen treatment in breast cancer prevention, and suggest that fibroblast growth factor receptor 2 signalling has an important role in mediating breast cancer risk.
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Müller G, Martino-Andrade AJ, Santos AS, Reghelin AL, Garcia DM, Sant'Ana GR, Spercoski KM, Meyer KB, Torres SM, Silva Júnior VA, Morais RN. Testicular testosterone: estradiol ratio in domestic cats and its relationship to spermatogenesis and epididymal sperm morphology. Theriogenology 2012; 78:1224-34. [PMID: 22898016 DOI: 10.1016/j.theriogenology.2012.05.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 04/13/2012] [Accepted: 05/21/2012] [Indexed: 12/15/2022]
Abstract
The phenomenon of teratozoospermia in felids is not fully understood. In this study, we investigated the testicular androgen:estrogen balance in domestic cats and correlated these data with epididymal sperm morphology and the degree of spermatogenic activity. During spring and summer, testes and blood samples were obtained from 37 mixed-breed domestic cats (12 to 48 mo). The epididymal sperm were harvested and evaluated for sperm counts, motility, and morphology. Distal cytoplasmic droplets were not considered a defect, and samples were considered normozoospermic if they contained more than 60% normal sperm (N = 25) or teratozoospermic if they contained less than 45% normal sperm (N = 12). The testicular and serum concentrations of testosterone (T) and 17β-estradiol (E2) were determined with an enzyme immunoassay. The gonadosomatic index and epididymal sperm numbers and motility did not differ between groups. The percentage of normal sperm was higher in normozoospermic (74.3 ± 2.0, mean ± SEM) than in teratozoospermic samples (43.1 ± 1.4). The most prevalent sperm defects in the teratozoospermic group were abnormal acrosomes (9.7 ± 2.0) and bent midpieces (12.2 ± 2.0) or tails (24.0 ± 2.7) with cytoplasmic droplets. Histomorphometric data were similar between groups, although there was a lower Leydig cell nuclear volume in teratozoospermic samples. Normozoospermic samples contained a higher percentage of haploid cells and had a higher index of total spermatogenic transformation than teratozoospermic samples. Serum concentrations of T (0.5 ± 0.1 vs. 0.8 ± 0.4 ng/mL) and E2 (9.5 ± 1.2 vs. 11.4 ± 2.3 pg/mL) and testicular T concentrations (471.6 ± 65.3 vs. 313.4 ± 57.6 ng/g) were similar between groups. However, compared with normozoospermic samples, teratozoospermic samples had higher testicular E2 concentrations (8.5 ± 3.6 vs. 5.4 ± 0.5 ng/g) and a lower T:E2 ratio (31.8 ± 4.1 vs. 87.2 ± 11.6). There were significant correlations between testicular E2 values and percentages of normal sperm (r = -0.55) as well as those with primary sperm defects (r = 0.58) or abnormal acrosomes (r = 0.64). The T:E2 ratio was also correlated with meiotic index (r = 0.45) and percentage of normal sperm (r = 0.58). In conclusion, a high testicular E2 concentration and a reduced T:E2 ratio were significantly associated with higher ratios of abnormal sperm types, suggesting that the balance between androgens and estrogens is an important endocrine component in the genesis of teratozoospermia in felids.
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Castro MAA, Wang X, Fletcher MNC, Meyer KB, Markowetz F. RedeR: R/Bioconductor package for representing modular structures, nested networks and multiple levels of hierarchical associations. Genome Biol 2012; 13:R29. [PMID: 22531049 PMCID: PMC3446303 DOI: 10.1186/gb-2012-13-4-r29] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 03/23/2012] [Accepted: 04/24/2012] [Indexed: 11/12/2022] Open
Abstract
Visualization and analysis of molecular networks are both central to systems biology. However, there still exists a large technological gap between them, especially when assessing multiple network levels or hierarchies. Here we present RedeR, an R/Bioconductor package combined with a Java core engine for representing modular networks. The functionality of RedeR is demonstrated in two different scenarios: hierarchical and modular organization in gene co-expression networks and nested structures in time-course gene expression subnetworks. Our results demonstrate RedeR as a new framework to deal with the multiple network levels that are inherent to complex biological systems. RedeR is available from http://bioconductor.org/packages/release/bioc/html/RedeR.html.
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Meyer KB, Maia AT, O'Reilly M, Ghoussaini M, Prathalingam R, Porter-Gill P, Ambs S, Prokunina-Olsson L, Carroll J, Ponder BAJ. A functional variant at a prostate cancer predisposition locus at 8q24 is associated with PVT1 expression. PLoS Genet 2011; 7:e1002165. [PMID: 21814516 PMCID: PMC3140991 DOI: 10.1371/journal.pgen.1002165] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Accepted: 05/18/2011] [Indexed: 01/09/2023] Open
Abstract
Genetic mapping studies have identified multiple cancer susceptibility regions at chromosome 8q24, upstream of the MYC oncogene. MYC has been widely presumed as the regulated target gene, but definitive evidence functionally linking these cancer regions with MYC has been difficult to obtain. Here we examined candidate functional variants of a haplotype block at 8q24 encompassing the two independent risk alleles for prostate and breast cancer, rs620861 and rs13281615. We used the mapping of DNase I hypersensitive sites as a tool to prioritise regions for further functional analysis. This approach identified rs378854, which is in complete linkage disequilibrium (LD) with rs620861, as a novel functional prostate cancer-specific genetic variant. We demonstrate that the risk allele (G) of rs378854 reduces binding of the transcription factor YY1 in vitro. This factor is known to repress global transcription in prostate cancer and is a candidate tumour suppressor. Additional experiments showed that the YY1 binding site is occupied in vivo in prostate cancer, but not breast cancer cells, consistent with the observed cancer-specific effects of this single nucleotide polymorphism (SNP). Using chromatin conformation capture (3C) experiments, we found that the region surrounding rs378854 interacts with the MYC and PVT1 promoters. Moreover, expression of the PVT1 oncogene in normal prostate tissue increased with the presence of the risk allele of rs378854, while expression of MYC was not affected. In conclusion, we identified a new functional prostate cancer risk variant at the 8q24 locus, rs378854 allele G, that reduces binding of the YY1 protein and is associated with increased expression of PVT1 located 0.5 Mb downstream.
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Udler MS, Meyer KB, Pooley KA, Karlins E, Struewing JP, Zhang J, Doody DR, MacArthur S, Tyrer J, Pharoah PD, Luben R, Bernstein L, Kolonel LN, Henderson BE, Le Marchand L, Ursin G, Press MF, Brennan P, Sangrajrang S, Gaborieau V, Odefrey F, Shen CY, Wu PE, Wang HC, Kang D, Yoo KY, Noh DY, Ahn SH, Ponder BA, Haiman CA, Malone KE, Dunning AM, Ostrander EA, Easton DF. FGFR2 variants and breast cancer risk: fine-scale mapping using African American studies and analysis of chromatin conformation. Hum Mol Genet 2009; 18:1692-703. [PMID: 19223389 PMCID: PMC2733817 DOI: 10.1093/hmg/ddp078] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Accepted: 02/13/2009] [Indexed: 12/29/2022] Open
Abstract
Genome-wide association studies have identified FGFR2 as a breast cancer (BC) susceptibility gene in populations of European and Asian descent, but a causative variant has not yet been conclusively identified. We hypothesized that the weaker linkage disequilibrium across this associated region in populations of African ancestry might help refine the set of candidate-causal single nucleotide polymorphisms (SNPs) previously identified by our group. Eight candidate-causal SNPs were evaluated in 1253 African American invasive BC cases and 1245 controls. A significant association with BC risk was found with SNP rs2981578 (unadjusted per-allele odds ratio = 1.20, 95% confidence interval 1.03-1.41, P(trend) = 0.02), with the odds ratio estimate similar to that reported in European and Asian subjects. To extend the fine-mapping, genotype data from the African American studies were analyzed jointly with data from European (n = 7196 cases, 7275 controls) and Asian (n = 3901 cases, 3205 controls) studies. In the combined analysis, SNP rs2981578 was the most strongly associated. Five other SNPs were too strongly correlated to be excluded at a likelihood ratio of < 1/100 relative to rs2981578. Analysis of DNase I hypersensitive sites indicated that only two of these map to highly accessible chromatin, one of which, SNP rs2981578, has previously been implicated in up-regulating FGFR2 expression. Our results demonstrate that the association of SNPs in FGFR2 with BC risk extends to women of African American ethnicity, and illustrate the utility of combining association analysis in datasets of diverse ethnic groups with functional experiments to identify disease susceptibility variants.
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Meyer KB, Maia AT, O'Reilly M, Teschendorff AE, Chin SF, Caldas C, Ponder BAJ. Allele-specific up-regulation of FGFR2 increases susceptibility to breast cancer. PLoS Biol 2008; 6:e108. [PMID: 18462018 PMCID: PMC2365982 DOI: 10.1371/journal.pbio.0060108] [Citation(s) in RCA: 233] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Accepted: 03/20/2008] [Indexed: 11/19/2022] Open
Abstract
The recent whole-genome scan for breast cancer has revealed the FGFR2 (fibroblast growth factor receptor 2) gene as a locus associated with a small, but highly significant, increase in the risk of developing breast cancer. Using fine-scale genetic mapping of the region, it has been possible to narrow the causative locus to a haplotype of eight strongly linked single nucleotide polymorphisms (SNPs) spanning a region of 7.5 kilobases (kb) in the second intron of the FGFR2 gene. Here we describe a functional analysis to define the causative SNP, and we propose a model for a disease mechanism. Using gene expression microarray data, we observed a trend of increased FGFR2 expression in the rare homozygotes. This trend was confirmed using real-time (RT) PCR, with the difference between the rare and the common homozygotes yielding a Wilcox p-value of 0.028. To elucidate which SNPs might be responsible for this difference, we examined protein–DNA interactions for the eight most strongly disease-associated SNPs in different breast cell lines. We identify two cis-regulatory SNPs that alter binding affinity for transcription factors Oct-1/Runx2 and C/EBPβ, and we demonstrate that both sites are occupied in vivo. In transient transfection experiments, the two SNPs can synergize giving rise to increased FGFR2 expression. We propose a model in which the Oct-1/Runx2 and C/EBPβ binding sites in the disease-associated allele are able to lead to an increase in FGFR2 gene expression, thereby increasing the propensity for tumour formation. Recently, a number of whole-genome association studies have identified genes that predispose individuals to common diseases such as cancer. The challenge now is to understand how the identified risk loci contribute to disease, since the majority of these loci are located within introns (which are discarded after transcription) and intergenic regions, and therefore do not change the coding region of nearby genes. This manuscript describes how two single–base pair changes in intron 2 of the FGFR2 (fibroblast growth factor receptor 2) gene, “the top hit” of the breast cancer susceptibility study, exert their function. We find that the changes alter the binding of two transcription factors and cause an increase in FGFR2 gene expression, thus providing a molecular explanation for the risk phenotype. This is the first functional study, to our knowledge, of the risk loci identified for breast cancer in a whole-genome scan and demonstrates that these studies can be used as valid starting points for studying the underlying biology of cancer. Recent whole-genome scans have identified novel risk genes for many common diseases, challenging researchers to determine how these genes contribute to disease. A new study provides molecular insights into a breast cancer risk factor.
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Easton DF, Pooley KA, Dunning AM, Pharoah PDP, Thompson D, Ballinger DG, Struewing JP, Morrison J, Field H, Luben R, Wareham N, Ahmed S, Healey CS, Bowman R, Meyer KB, Haiman CA, Kolonel LK, Henderson BE, Le Marchand L, Brennan P, Sangrajrang S, Gaborieau V, Odefrey F, Shen CY, Wu PE, Wang HC, Eccles D, Evans DG, Peto J, Fletcher O, Johnson N, Seal S, Stratton MR, Rahman N, Chenevix-Trench G, Bojesen SE, Nordestgaard BG, Axelsson CK, Garcia-Closas M, Brinton L, Chanock S, Lissowska J, Peplonska B, Nevanlinna H, Fagerholm R, Eerola H, Kang D, Yoo KY, Noh DY, Ahn SH, Hunter DJ, Hankinson SE, Cox DG, Hall P, Wedren S, Liu J, Low YL, Bogdanova N, Schürmann P, Dörk T, Tollenaar RAEM, Jacobi CE, Devilee P, Klijn JGM, Sigurdson AJ, Doody MM, Alexander BH, Zhang J, Cox A, Brock IW, MacPherson G, Reed MWR, Couch FJ, Goode EL, Olson JE, Meijers-Heijboer H, van den Ouweland A, Uitterlinden A, Rivadeneira F, Milne RL, Ribas G, Gonzalez-Neira A, Benitez J, Hopper JL, McCredie M, Southey M, Giles GG, Schroen C, Justenhoven C, Brauch H, Hamann U, Ko YD, Spurdle AB, Beesley J, Chen X, Mannermaa A, Kosma VM, Kataja V, Hartikainen J, Day NE, Cox DR, Ponder BAJ. Genome-wide association study identifies novel breast cancer susceptibility loci. Nature 2007; 447:1087-93. [PMID: 17529967 PMCID: PMC2714974 DOI: 10.1038/nature05887] [Citation(s) in RCA: 1676] [Impact Index Per Article: 98.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Accepted: 04/30/2007] [Indexed: 12/17/2022]
Abstract
Breast cancer exhibits familial aggregation, consistent with variation in genetic susceptibility to the disease. Known susceptibility genes account for less than 25% of the familial risk of breast cancer, and the residual genetic variance is likely to be due to variants conferring more moderate risks. To identify further susceptibility alleles, we conducted a two-stage genome-wide association study in 4,398 breast cancer cases and 4,316 controls, followed by a third stage in which 30 single nucleotide polymorphisms (SNPs) were tested for confirmation in 21,860 cases and 22,578 controls from 22 studies. We used 227,876 SNPs that were estimated to correlate with 77% of known common SNPs in Europeans at r2 > 0.5. SNPs in five novel independent loci exhibited strong and consistent evidence of association with breast cancer (P < 10(-7)). Four of these contain plausible causative genes (FGFR2, TNRC9, MAP3K1 and LSP1). At the second stage, 1,792 SNPs were significant at the P < 0.05 level compared with an estimated 1,343 that would be expected by chance, indicating that many additional common susceptibility alleles may be identifiable by this approach.
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Tentori F, Hunt WC, Stidley CA, Rohrscheib MR, Bedrick EJ, Meyer KB, Johnson HK, Zager PG. Mortality risk among hemodialysis patients receiving different vitamin D analogs. Kidney Int 2006; 70:1858-65. [PMID: 17021609 DOI: 10.1038/sj.ki.5001868] [Citation(s) in RCA: 321] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Intravenous vitamin D is standard therapy for secondary hyperparathyroidism in hemodialysis (HD) patients. In for-profit dialysis clinics, mortality was higher for patients on calcitriol compared to paricalcitol. Doxercalciferol, a second vitamin D2 analog, is currently available. We assessed mortality associated with each vitamin D analog and with lack of vitamin D therapy in patients who began HD at Dialysis Clinic Inc. (DCI), a not-for-profit dialysis provider. During the 1999-2004 study period we studied 7731 patients (calcitriol: n=3212; paricalcitol: n=2087; doxercalciferol: n=2432). Median follow-up was 37 weeks. Mortality rates (deaths/100 patient-years) were identical in patients on doxercalciferol (15.4, 95% confidence interval (13.6-17.1)) and paricalcitol (15.3 (13.6-16.9)) and higher in patients on calcitriol (19.6 (18.2-21.1)) (P<0.0001). In all models mortality was similar for paricalcitol versus doxercalciferol (hazard ratios=1.0). In unadjusted models, mortality was lower in patients on doxercalciferol (0.80 (0.66, 0.96)) and paricalcitol (0.79 (0.68, 0.92)) versus calcitriol (P<0.05). In adjusted models, this difference was not statistically significant. In all models mortality was higher for patients who did not receive vitamin D versus those who did (1.2 (1.1-1.3)). Mortality in doxercalciferol- and paricalcitol-treated patients was virtually identical. Differences in survival between vitamin D2 and D3 may be smaller than previously reported.
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Conlon TM, Meyer KB. The chicken Ig light chain 3′-enhancer is essential for gene expression and regulates gene conversionvia the transcription factor E2A. Eur J Immunol 2006; 36:139-48. [PMID: 16342328 DOI: 10.1002/eji.200535219] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Expression of the rearranged chicken immunoglobulin light chain (IgL) gene is regulated by a V gene promoter, a matrix attachment region (MAR) in the J-C intron and an enhancer downstream of the Ig constant region. Using knockout analysis, we demonstrate that the 3'-enhancer is not only required for gene activation but is also essential for the maintenance of gene expression. Deletion of the MAR on the other hand increases IgL transcription, indicating that the MAR acts as negative regulator. We demonstrate that Id1 and Id3, dominant-negative regulators of basic-region helix-loop-helix (bHLH) transcription factors, are able to reduce chicken IgL 3'-enhancer activity in transient assays and strongly reduce the rate of gene conversion (GC) in DT40 clone 18 cells. Conversely, overexpression of avian E47, a bHLH transcription factor, leads to a dramatic increase in GC rates independent of IgL or activation-induced cytidine deaminase RNA levels. Thus, E47 is the first transcription factor to activate GC without an apparent increase in transcription.
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Conlon TM, Meyer KB. Cloning and functional characterisation of avian transcription factor E2A. BMC Immunol 2004; 5:11. [PMID: 15196311 PMCID: PMC446191 DOI: 10.1186/1471-2172-5-11] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2004] [Accepted: 06/14/2004] [Indexed: 11/10/2022] Open
Abstract
Background During B lymphocyte development the E2A gene is a critical regulator of cell proliferation and differentiation. With regards to the immunoglobulin genes the E2A proteins contribute to the regulation of gene rearrangement, expression and class switch recombination. We are now using the chicken cell line DT40 as a model system to further analyse the function of E2A. Results Here we report the cloning and functional analysis of the transcription factor E2A from chicken. Using RACE PCR on the chicken lymphoma cell line DT40 we have isolated full-length clones for the two E2A splice variants E12 and E47. Sequence conservation between the human and chicken proteins is extensive: the basic-helix-loop-helix DNA binding domain of human and chicken E47 and E12 are 93% and 92% identical, respectively. In addition high levels of conservation are seen in activation domain I, the potential NLS and the ubiquitin ligase interaction domain. E2A is expressed in a variety of tissues in chicken, with higher levels of expression in organs rich in immune cells. We demonstrate that chicken E12 and E47 proteins are strong transcriptional activators whose function depends on the presence of activation domain I. As in mammals, the dominant negative proteins Id1 and Id3 can inhibit the function of chicken E47. Conclusions The potential for homologous recombination in DT40 allows the genetic dissection of biochemical pathways in somatic cells. With the cloning of avian E2A and the recent description of an in vitro somatic hypermutation assay in this cell line, it should now be possible to dissect the potential role of E2A in the regulation of somatic hypermutation and gene conversion.
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Miskulin DC, Athienites NV, Yan G, Martin AA, Ornt DB, Kusek JW, Meyer KB, Levey AS. Comorbidity assessment using the Index of Coexistent Diseases in a multicenter clinical trial. Kidney Int 2001; 60:1498-510. [PMID: 11576365 DOI: 10.1046/j.1523-1755.2001.00954.x] [Citation(s) in RCA: 141] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The Hemodialysis (HEMO) Study is a multicenter trial designed to determine whether hemodialysis dose and membrane flux affect survival. Comorbid conditions are also important determinants of survival, and thus, an accurate and reliable method to assess comorbidity was required. Comorbidity was being assessed at baseline and annually in the HEMO Study using the Index of Coexistent Disease (ICED). We describe the instrument, its implementation in the HEMO Study, and the results of comorbidity assessment in the first 1000 randomized patients in the trial. METHODS The ICED aggregated the presence and severity of 19 medical conditions and 11 physical impairments within two scales: the Index of Disease Severity (IDS) and the Index of Physical Impairment (IPI). The final ICED score was determined by an algorithm combining the peak scores for the IDS and IPI. The range of the ICED was from 0 to 3, reflecting increasing severity. RESULTS Study personnel at 15 clinical centers were trained to update and abstract data from the dialysis medical records. Availability of data, measures of construct validity, and measures of reliability were adequate; 99.8% and 60.6% of patients had comorbid conditions in at least one IDS or IPI category, respectively. The distribution of patients by ICED level was 0 (0.2%), 1 (34.9%), 2 (31.2%), and 3 (33.7%). In multivariable analysis, the following factors were significantly associated with more severe comorbidity: older age, diabetes and other causes of renal disease, a lower level of education, employment status (unemployed and retired), longer duration of dialysis, and lower serum creatinine. There was a significant variation in the severity of comorbidity among clinical centers after adjustment for other factors. The R2 of the model was 25.3%, indicating that a substantial proportion of the variation in the ICED was not explained by these factors. CONCLUSIONS We conclude that comorbidity assessment using the ICED is feasible in multicenter clinical trials of dialysis patients. There is a large burden of comorbidity in dialysis patients, which is not well explained by the cause of renal disease, demographic, and socioeconomic factors and common clinical and laboratory measurements. These variables should not be considered substitutes for comorbid conditions in case-mix adjustment. Comorbidity assessment is useful to describe the sample population, to improve the precision of the treatment effect, and to use possibly as an outcome measurement.
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Wu AW, Fink NE, Cagney KA, Bass EB, Rubin HR, Meyer KB, Sadler JH, Powe NR. Developing a health-related quality-of-life measure for end-stage renal disease: The CHOICE Health Experience Questionnaire. Am J Kidney Dis 2001; 37:11-21. [PMID: 11136162 DOI: 10.1053/ajkd.2001.20631] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The Choices for Healthy Outcomes in Caring for End-Stage Renal Disease ([ESRD] CHOICE) Study was designed to evaluate the effectiveness of alternative dialysis prescriptions. As part of CHOICE, we developed an instrument for measuring health-related quality of life (HRQOL) for patients with ESRD that would complement the Medical Outcomes Study 36-Item Short-Form Survey (SF-36) and be sensitive to differences in dialysis modality (hemodialysis [HD] and peritoneal dialysis [PD]) and dialysis dose. The selection of HRQOL domains to be included was based on: (1) a structured literature review of 47 articles describing 53 different instruments; (2) content analysis of five focus groups with HD and PD patients, nephrologists, and other providers; (3) a survey of 110 dialysis providers about features of different modalities that affect patient HRQOL; and (4) a semistructured survey of 25 patients with ESRD on the effects of dialysis on functioning and HRQOL. To help prioritize domains and items identified by these methods, a representative sample of 136 dialysis patients rated each item for frequency and bother. A panel of nephrologists provided advice about the salience of items to modality or dose. Items and scales were selected with a preference for existing measures tested in patients with ESRD and were tested for reliability and validity. The first four steps yielded 22 HRQOL domains that included 96 items: 8 generic domains in the SF-36 (health perceptions, physical, social, physical and emotional role function, pain, mental health, and energy); 8 additional generic domains (cognitive functioning, sexual functioning, sleep, work, recreation, travel, finances, and general quality of life); and 6 ESRD-specific domains (diet, freedom, time, body image, dialysis access [catheters and/or vascular], and symptoms). New items were developed or adapted to assess ESRD-specific domains. Scales for these items showed adequate internal consistency (Cronbach's alpha > 0.70, except for time [alpha = 0.57] and quality of life [alpha = 0.68]), as well as convergent and discriminant construct validity in a sample of 928 patients. The final questionnaire included 21 domains (time was deleted) and 83 items. We have designed a patient-centered instrument, the CHOICE Health Experience Questionnaire, that addresses domains that may be sensitive to differences in dialysis modality and dose and shows evidence for reliability and validity as a measure of HRQOL in ESRD.
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Athienites NV, Miskulin DC, Fernandez G, Bunnapradist S, Simon G, Landa M, Schmid CH, Greenfield S, Levey AS, Meyer KB. Comorbidity assessment in hemodialysis and peritoneal dialysis using the index of coexistent disease. Semin Dial 2000; 13:320-6. [PMID: 11014695 DOI: 10.1046/j.1525-139x.2000.00095.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The purpose of this paper is to describe the ICED, summarize outcomes of prior studies in which it was used, and describe the adaptations that have lead to the present instrument. We will then demonstrate its use in quantifying the burden of comorbid conditions in a sample of hemodialysis and peritoneal dialysis patients from our center, and show the relationship between ICED levels and outcomes in peritoneal dialysis patients.
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Cagney KA, Wu AW, Fink NE, Jenckes MW, Meyer KB, Bass EB, Powe NR. Formal literature review of quality-of-life instruments used in end-stage renal disease. Am J Kidney Dis 2000; 36:327-36. [PMID: 10922311 DOI: 10.1053/ajkd.2000.8982] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Although quality-of-life assessment is an important complement to conventional clinical evaluation, there are limited opportunities for researchers in end-stage renal disease (ESRD) to examine evidence for a range of quality-of-life measures. To better understand how quality of life has been conceptualized, measured, and evaluated for ESRD, we conducted a structured literature review. Eligible articles were identified from a MEDLINE search, expert input, and review of references from eligible articles. A standardized instrument was created for article review and included type of measure, instrument development process, study sample characteristics, quality-of-life domains, and reliability and validity testing. From 436 citations, 78 articles were eligible for final review, and of those, 47 articles contained evidence of reliability or validity testing. Within this set, there were 113 uses of 53 different instruments: 82% were generic and 18% were disease specific. Only 32% defined quality of life. The most frequently assessed domains were depression (41%), social functioning (32%), positive affect (30%), and role functioning (27%). Testing was completed for test-retest reliability (20%), interrater reliability (13%), internal consistency (22%), content validity (24%), construct validity (41%), criterion validity (55%), and responsiveness (59%). Few articles measuring quality of life in ESRD defined quality-of-life domains or adequately described instrument development and testing. Generic measures, such as the Sickness Impact Profile, and disease-specific measures, such as the Kidney Disease Questionnaire, had been tested more thoroughly than others. Standardized reporting and more rigorous testing could help researchers make informed choices about instruments that would best serve their own and their patients' needs.
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Abstract
The transcription factor E2A plays a crucial role in B cell development, the control of immunoglobulin gene rearrangement and expression. Here we report that in primary mouse B cells lipopolysaccharide (LPS) is able to induce the level of E2A protein by over 50-fold in days of culture. In contrast, CD40 signaling is insufficient to cause an E2A increase and can in fact prevent the LPS-mediated induction of E2A. These results suggest that E2A induction requires both proliferation and differentiation. We find that E2A protein induction is regulated post-transcriptionally since E2A mRNA is not induced by LPS. We have thus identified an important additional layer of regulation affecting the activity of E2A transcription factors.
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