65 research outputs found
Diet and Leukocyte Telomere Length in a Population with Extended Longevity: The Costa Rican Longevity and Healthy Aging Study (CRELES)
Elderly Costa Ricans have lower mortality rates compared to their counterparts from
developed countries. Reasons for this survival advantage are not completely known. In the present
study, we aimed to identify dietary factors associated with leukocyte telomere length (LTL), a marker
of biologic aging, in the elderly population of Costa Rica. We conducted prospective analysis in
909 participants aged 60+ years from the Costa Rican Longevity and Healthy Aging Study (CRELES).
We used a food frequency questionnaire to assess usual diet. We calculated dietary patterns using
Principal Component Analysis (PCA). We used generalized linear models to examine the association
of dietary patterns and food groups with leukocyte telomere length. We found two major dietary
patterns explaining 9.15% and 7.18% of the total variation of food intake, respectively. The first dietary
pattern, which represents a traditional Costa Rican rice and beans pattern, was more frequent in rural
parts of the country and was positively associated with baseline LTL: (95% CI) = 42.0 base-pairs (bp)
(9.9 bp, 74.1 bp) per one-unit increase of the traditional dietary pattern. In analysis of individual
food groups, intake of grains was positively associated with baseline LTL: (95% CI) = 43.6 bp
(13.9 bp, 73.3 bp) per one-serving/day increase of consumption of grains. Our results suggest that
dietary factors, in particular a traditional food pattern, are associated with telomere length and may
contribute to the extended longevity of elderly Costa Ricans.Universidad de Costa Rica/[]/UCR/Costa RicaNational Institutes of Health/[P30 AG012839]/NIH/Estados UnidosNational Institutes of Health/[R01 AG031716]/NIH/Estados UnidosUCR::VicerrectorÃa de Investigación::Unidades de Investigación::Ciencias Sociales::Centro Centroamericano de Población (CCP)UCR::VicerrectorÃa de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de BiologÃ
The STR polymorphism (AAAAT)n within the intron 1 of the tumor protein 53 (TP53) locus in 17 populations of different ethnic groups of Africa, America, Asia and Europe
artÃculo arbitrado -- Universidad de Costa Rica, Instituto de investigaciones en Salud. 2004The SIR (A.AAAT). within intron 1 of the TP53 Locus was screened in 17 populations from 3 main
ethnic groups: Europeans, Asiatics, and Africans. and from the hybrid population of Costa Rica (1968 samples).
Three alleles, 126)7 (bp/copies of the repeat), 13118 and 136/9 were the most prevalent in all populations. Other
alleles rarely reached frequencies of 10% or higher. Observed heterozygosities ranged between 0.351 and 0.829.
Patterns of diversity fit well with both the geographic origin of the samples and the history of the populations
screened. A statistical test suggests that single-step mutational events have been the main mechanism producing
new alleles at this locus. Fixation indexes (R57) for this marker showed an effect of population subdivision on
divergence only within the Asiatic group; they were insensitive at the level of major ethnic groups as well as
within Africans and within EuropeansSe estudio el polimorfismo del microsatelite
(AAAAI), del intron 1 del gene TP53 en 17 poblaciones
de 3 grupos etnicos: europeos, asiaticos, y africanos subsaharianos,
asi coma de la poblacion hibrida de Costa Rica
(en total 1968 muestras). Tres aides, 12617 (pares de bases/
copias de la repetición), 131/8 y 136/9 fueron los mas
frecuentes en todas las poblaciones, aunque se observaron
otros alelos usualmente a frecuencias menores al 10%. Las
heterocigosis observadas variaron de 0.351 a 0.829. La
distribucion de la universidad parece concordar con el origen
geográfico de las muestras y con la historia de las poblaciones
estudiadas. Una prueba estadÃstica indica que el
evento mutacional que mas alelos nuevos produce en ese
marcador es el de un solo paso (expansión o contracción
de una cola copia de la repeticion). El indice de fijacion
R„ mostro los efectos de la subdivision de poblaciones
solo dentro del grupo de los asiaticos y mostro falta de sensibilidad
cuando los grupos comparados eran de nivetes
superiores de clasificacion (europeos, asiaticos, y africanos)
o cuando la comparación se hizo entre los grupos mas
antiguos (africanos y europeos).Universidad de costa Rica, Instituto de investigaciones en Salud.UCR::VicerrectorÃa de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA
Gene-based analysis of the fibroblast growth factor receptor signaling pathway in relation to breast cancer in African American women: the AMBER consortium
We conducted gene-based analysis in 26 genes in the FGFR signaling pathway to identify genes carrying genetic variation affecting risk of breast cancer and the specific estrogen receptor (ER) subtypes
Family History of Cancer in Relation to Breast Cancer Subtypes in African American Women
Evidence on the relation of family history of cancers other than breast cancer to breast cancer risk is conflicting and most studies have not assessed specific breast cancer subtypes
An exome-wide analysis of low frequency and rare variants in relation to risk of breast cancer in African American Women: the AMBER Consortium
A large percentage of breast cancer heritability remains unaccounted for, and most of the known susceptibility loci have been established in European and Asian populations. Rare variants may contribute to the unexplained heritability of this disease, including in women of African ancestry (AA). We conducted an exome-wide analysis of rare variants in relation to risk of overall and subtype-specific breast cancer in the African American Breast Cancer Epidemiology and Risk (AMBER) Consortium, which includes data from four large studies of AA women. Genotyping on the Illumina Human Exome Beadchip yielded data for 170 812 SNPs and 8287 subjects: 3629 cases (1093 estrogen receptor negative (ER−), 1968 ER+, 568 ER unknown) and 4658 controls, the largest exome chip study to date for AA breast cancer. Pooled gene-based association analyses were performed using the unified optimal sequence kernel association test (SKAT-O) for variants with minor allele frequency (MAF) ≤ 5%. In addition, each variant with MAF >0.5% was tested for association using logistic regression. There were no significant associations with overall breast cancer. However, a novel gene, FBXL22 (P = 8.2×10–6), and a gene previously identified in GWAS of European ancestry populations, PDE4D (P = 1.2×10–6), were significantly associated with ER− breast cancer after correction for multiple testing. Cases with the associated rare variants were also negative for progesterone and human epidermal growth factor receptors—thus, triple-negative cancer. Replication is required to confirm these gene-level associations, which are based on very small counts at extremely rare SNPs
Genetic variants in the mTOR pathway and breast cancer risk in African American women
The phosphatidylinositol 3-kinase–AKT–mammalian target of rapamycin (mTOR) pathway has been implicated in breast carcinogenesis. However, there has been no large-scale investigation of genetic variants in the mTOR pathway and breast cancer risk. We examined 28847 single-nucleotide polymorphisms (SNPs) in 61 mTOR pathway genes in the African American Breast Cancer Epidemiology and Risk consortium of 3663 cases [1983 estrogen receptor-positive (ER+) and 1098 ER-negative (ER−)] and 4687 controls. Gene-level analyses were conducted using the adaptive rank truncated product (ARTP) test for 10773 SNPs that were not highly correlated (r 2 < 0.8), and SNP-level analyses were conducted with logistic regression. Among genes that were prioritized (nominal P < 0.05, ARTP tests), associations were observed for intronic SNPs TSC2 rs181088346 [odds ratio (OR) of each copy of variant allele = 0.77, 95% confidence interval (CI) = 0.65–0.88 for all breast cancer] and BRAF rs114729114 (OR = 1.53, 95% CI = 1.24–1.91 for all breast cancer and OR = 2.03, 95% CI = 1.50–2.76 for ER− tumors). For ER− tumors, intronic SNPs PGF rs11542848 (OR = 1.38, 95% CI = 1.15–1.66) and rs61759375 (OR = 1.34, 95% CI = 1.14–1.57) and MAPK3 rs78564187 (OR = 1.26, 95% CI = 1.11–1.43) were associated with increased risk. These SNPs were significant at a gene-wide level (Bonferroni-corrected P < 0.05). The variant allele of RPS6KB2 rs35363135, a synonymous coding SNP, was more likely to be observed in ER− than ER+ tumors (OR = 1.18, 95% CI = 1.05–1.31, gene-wide Bonferroni-corrected P = 0.06). In conclusion, specific mTOR pathway genes are potentially important to breast cancer risk and to the ER negativity in African American women
Admixture Mapping of African–American Women in the AMBER Consortium Identifies New Loci for Breast Cancer and Estrogen-Receptor Subtypes
Recent genetic admixture coupled with striking differences in incidence of estrogen receptor (ER) breast cancer subtypes, as well as severity, between women of African and European ancestry, provides an excellent rationale for performing admixture mapping in African American women with breast cancer risk. We performed the largest breast cancer admixture mapping study with in African American women to identify novel genomic regions associated with the disease. We conducted a genome-wide admixture scan using 2,624 autosomal ancestry informative markers (AIMs) in 3,629 breast cancer cases (including 1,968 ER-positive, 1093 ER-negative, and 601 triple-negative) and 4,658 controls from the African American Breast Cancer Epidemiology and Risk (AMBER) Consortium, a collaborative study of four large geographically different epidemiological studies of breast cancer in African American women. We used an independent case-control study to test for SNP association in regions with genome-wide significant admixture signals. We found two novel genome-wide significant regions of excess African ancestry, 4p16.1 and 17q25.1, associated with ER-positive breast cancer. Two regions known to harbor breast cancer variants, 10q26 and 11q13, were also identified with excess of African ancestry. Fine-mapping of the identified genome-wide significant regions suggests the presence of significant genetic associations with ER-positive breast cancer in 4p16.1 and 11q13. In summary, we identified three novel genomic regions associated with breast cancer risk by ER status, suggesting that additional previously unidentified variants may contribute to the racial differences in breast cancer risk in the African American population
A survey of microRNA single nucleotide polymorphisms identifies novel breast cancer susceptibility loci in a case-control, population-based study of African-American women
Abstract
Background
MicroRNAs (miRNAs) regulate gene expression and influence cancer. Primary transcripts of miRNAs (pri-miRNAs) are poorly annotated and little is known about the role of germline variation in miRNA genes and breast cancer (BC). We sought to identify germline miRNA variants associated with BC risk and tumor subtype among African-American (AA) women.
Methods
Under the African American Breast Cancer Epidemiology and Risk (AMBER) Consortium, genotyping and imputed data from four studies on BC in AA women were combined into a final dataset containing 224,188 miRNA gene single nucleotide polymorphisms (SNPs) for 8350 women: 3663 cases and 4687 controls. The primary miRNA sequence was identified for 566 miRNA genes expressed in Encyclopedia of DNA Elements (ENCODE) Tier 1 cell types and human pancreatic islets. Association analysis was conducted using logistic regression for BC status overall and by tumor subtype.
Results
A novel BC signal was localized to an 8.6-kb region of 17q25.3 by four SNPs (rs9913477, rs1428882938, rs28585511, and rs7502931) and remained statistically significant after multiple test correction (odds ratio (OR) = 1.44, 95% confidence interval (CI) = 1.26–1.65; p = 3.15 × 10−7; false discovery rate (FDR) = 0.03). These SNPs reside in a genomic location that includes both the predicted primary transcript of the noncoding miRNA gene MIR3065 and the first intron of the gene for brain-specific angiogenesis inhibitor 1-associated protein 2 (BAIAP2). Furthermore, miRNA-associated SNPs on chromosomes 1p32.3, 5q32, and 3p25.1 were the strongest signals for hormone receptor, luminal versus basal-like, and HER2 enrichment status, respectively. A second phase of genotyping (1397 BC cases, 2418 controls) that included two SNPs in the 8.6-kb region was used for validation and meta-analysis. While neither rs4969239 nor rs9913477 was validated, when meta-analyzed with the original dataset their association with BC remained directionally consistent (OR = 1.29, 95% CI = 1.16–1.44 (p = 4.18 × 10–6) and OR = 1.33, 95% CI = 1.17–1.51 (p = 1.6 × 10–5), respectively).
Conclusion
Germline genetic variation indicates that MIR3065 may play an important role in BC development and heterogeneity among AA women. Further investigation to determine the potential functional effects of these SNPs is warranted. This study contributes to our understanding of BC risk in AA women and highlights the complexity in evaluating variation in gene-dense regions of the human genome.https://deepblue.lib.umich.edu/bitstream/2027.42/144216/1/13058_2018_Article_964.pd
Hormone-related pathways and risk of breast cancer subtypes in African American women
We sought to investigate genetic variation in hormone pathways in relation to risk of overall and subtype-specific breast cancer in women of African ancestry (AA)
A survey of microRNA single nucleotide polymorphisms identifies novel breast cancer susceptibility loci in a case-control, population-based study of African-American women
Abstract
Background
MicroRNAs (miRNAs) regulate gene expression and influence cancer. Primary transcripts of miRNAs (pri-miRNAs) are poorly annotated and little is known about the role of germline variation in miRNA genes and breast cancer (BC). We sought to identify germline miRNA variants associated with BC risk and tumor subtype among African-American (AA) women.
Methods
Under the African American Breast Cancer Epidemiology and Risk (AMBER) Consortium, genotyping and imputed data from four studies on BC in AA women were combined into a final dataset containing 224,188 miRNA gene single nucleotide polymorphisms (SNPs) for 8350 women: 3663 cases and 4687 controls. The primary miRNA sequence was identified for 566 miRNA genes expressed in Encyclopedia of DNA Elements (ENCODE) Tier 1 cell types and human pancreatic islets. Association analysis was conducted using logistic regression for BC status overall and by tumor subtype.
Results
A novel BC signal was localized to an 8.6-kb region of 17q25.3 by four SNPs (rs9913477, rs1428882938, rs28585511, and rs7502931) and remained statistically significant after multiple test correction (odds ratio (OR) = 1.44, 95% confidence interval (CI) = 1.26–1.65; p = 3.15 × 10−7; false discovery rate (FDR) = 0.03). These SNPs reside in a genomic location that includes both the predicted primary transcript of the noncoding miRNA gene MIR3065 and the first intron of the gene for brain-specific angiogenesis inhibitor 1-associated protein 2 (BAIAP2). Furthermore, miRNA-associated SNPs on chromosomes 1p32.3, 5q32, and 3p25.1 were the strongest signals for hormone receptor, luminal versus basal-like, and HER2 enrichment status, respectively. A second phase of genotyping (1397 BC cases, 2418 controls) that included two SNPs in the 8.6-kb region was used for validation and meta-analysis. While neither rs4969239 nor rs9913477 was validated, when meta-analyzed with the original dataset their association with BC remained directionally consistent (OR = 1.29, 95% CI = 1.16–1.44 (p = 4.18 × 10–6) and OR = 1.33, 95% CI = 1.17–1.51 (p = 1.6 × 10–5), respectively).
Conclusion
Germline genetic variation indicates that MIR3065 may play an important role in BC development and heterogeneity among AA women. Further investigation to determine the potential functional effects of these SNPs is warranted. This study contributes to our understanding of BC risk in AA women and highlights the complexity in evaluating variation in gene-dense regions of the human genome
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