Comprehensive Analysis of Genetic Ancestry and Its Molecular Correlates in Cancer.
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ABSTRACT:
SUBMITTER: Carrot-Zhang J
PROVIDER: S-EPMC7328015 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Cellular and molecular aberrations contribute to the disparity of human cancer incidence and etiology between ancestry groups. Multiomics profiling in The Cancer Genome Atlas (TCGA) allows for querying of the molecular underpinnings of ancestry-specific discrepancies in human cancer. Here, we provide a protocol for integrative associative analysis of ancestry with molecular correlates, including somatic mutations, DNA methylation, mRNA transcription, miRNA transcription, and pathway activity, using TCGA data. This protocol can be generalized to analyze other cancer cohorts and human diseases. For complete details on the use and execution of this protocol, please refer to Carrot-Zhang et al. (2020).
| S-EPMC8082263 | biostudies-literature
Project description:BackgroundThere are known disparities in incidence and outcomes of colorectal cancer (CRC) by race and ethnicity. Some of these disparities may be mediated by molecular changes in tumors that occur at different rates across populations. Genetic ancestry is a measure complementary to race and ethnicity that can overcome missing data issues and better capture genetic similarity in admixed populations. We aimed to identify somatic mutations and tumor gene expression differences associated with both genetic ancestry and imputed race and ethnicity.MethodsSequencing was performed with the Tempus xT NGS 648-gene panel and whole exome capture RNA-Seq for 8454 primarily late-stage CRC patients. Genetic ancestry proportions for five continental groups-Africa (AFR), American indigenous (AMR), East Asia (EAS), Europe (EUR), and South Asia (SAS)-were estimated using ancestry informative markers. To address data gaps, race and ethnicity categories were imputed, resulting in assignments for 952 Hispanic/Latino, 420 non-Hispanic (NH) Asian, 1061 NH Black, and 5763 NH White individuals. We assessed association of genetic ancestry proportions and imputed race and ethnicity categories with somatic mutations in relevant CRC genes and in 2608 expression profiles, as well as 1957 consensus molecular subtypes (CMS).ResultsIncreased AFR ancestry was associated with higher odds of somatic mutations in APC, KRAS, and PIK3CA and lower odds of BRAF mutations. Additionally, increased EAS ancestry was associated with lower odds of mutations in KRAS, EUR with higher odds in BRAF, and the Hispanic/Latino category with lower odds in BRAF. Greater AFR ancestry and the NH Black category were associated with higher rates of CMS3, while a higher proportion of Hispanic/Latino patients exhibited indeterminate CMS classifications.ConclusionsMolecular differences in CRC tumor mutation frequencies and gene expression that may underlie observed differences by race and ethnicity were identified. The association of AFR ancestry with increased KRAS mutations aligns with higher CMS3 subtype rates in NH Black patients. The increase of indeterminate CMS in Hispanic/Latino patients suggests that subtype classification methods could benefit from enhanced patient diversity.
| S-EPMC11321170 | biostudies-literature
Project description:BACKGROUND:Given the scarcity of cell lines from underrepresented populations, it is imperative that genetic ancestry for these cell lines is characterized. Consequences of cell line mischaracterization include squandered resources and publication retractions. METHODS:We calculated genetic ancestry proportions for 15 cell lines to assess the accuracy of previous race/ethnicity classification and determine previously unknown estimates. DNA was extracted from cell lines and genotyped for ancestry informative markers representing West African (WA), Native American (NA), and European (EUR) ancestry. RESULTS:Of the cell lines tested, all previously classified as White/Caucasian were accurately described with mean EUR ancestry proportions of 97%. Cell lines previously classified as Black/African American were not always accurately described. For instance, the 22Rv1 prostate cancer cell line was recently found to carry mixed genetic ancestry using a much smaller panel of markers. However, our more comprehensive analysis determined the 22Rv1 cell line carries 99% EUR ancestry. Most notably, the E006AA-hT prostate cancer cell line, classified as African American, was found to carry 92% EUR ancestry. We also determined the MDA-MB-468 breast cancer cell line carries 23% NA ancestry, suggesting possible Afro-Hispanic/Latina ancestry. CONCLUSIONS:Our results suggest predominantly EUR ancestry for the White/Caucasian-designated cell lines, yet high variance in ancestry for the Black/African American-designated cell lines. In addition, we revealed an extreme misclassification of the E006AA-hT cell line. IMPACT:Genetic ancestry estimates offer more sophisticated characterization leading to better contextualization of findings. Ancestry estimates should be provided for all cell lines to avoid erroneous conclusions in disparities literature.
| S-EPMC6548687 | biostudies-literature
Project description:The etiology behind cancer-related fatigue (CRF) is currently unknown. The physiological mechanisms of CRF are based on limited evidence that genetic factors, energy expenditure, metabolism, aerobic capacity, and the individual's immune response to inflammation are responsible for the experience of CRF. Gene expression profiling using microarray analysis from white blood cells of men with non-metastatic prostate cancer shows significant, differential expression of 463 probesets during localized external beam radiation therapy (EBRT). Pathway analysis shows a central role of SNCA (alpha-synuclein gene) among these differentially expressed probesets. Significant expression of SNCA was confirmed by qPCR (p<.001) and ELISA (p<.001) over time during EBRT. A significant correlation was noted between averaged fatigue scores and delta CT values of SNCA expression using confirmatory qPCR over time during EBRT (R=-.90, p=.006). Development of fatigue experienced by these men during EBRT may be mediated by SNCA expression. Pathways related to alpha-synuclein may serve as useful biomarkers to understand the mechanisms behind the development of fatigue. A longitudinal design exploring the association between changes in gene expression and fatigue symptoms of men with non-metastatic prostate cancer receiving external beam radiation therapy. Blood samples were collected from ten subjects at 7 timepoints for microarray analysis: baseline (before EBRT); days 1, 7, 14, 21, 42 of EBRT; and 30 days post-EBRT. Baseline data obtained from subjects were compared to data obtained from age-, race-, and gender-matched healthy controls.
2012-12-21 | E-GEOD-30174 | biostudies-arrayexpress
Project description:The genetic heterogeneity of sensorineural hearing loss (SNHL) is a major hurdle to the detection of disease-causing variants. We aimed to identify underlying causal genes associated with mid-frequency hearing loss (HL), which contributes to less than about 1% of SNHL cases, by whole exome sequencing (WES). Thirty families segregating mid-frequency SNHL, in whom biallelic GJB2 mutations had been previously excluded, were selected from among 851 families in our DNA repository of SNHL. DNA samples from the probands were subjected to WES analysis and searched for candidate variants associated with SNHL. We were able to identify the genetic aetiology in six probands (20%). In total, we found three pathogenic and three likely pathogenic variants in four genes (COL4A5, OTOGL, TECTA, TMPRSS3). One more proband was a compound heterozygote for a pathogenic variant and a variant of uncertain significance (VUS) in MYO15A gene. To date, MYO15A and TMPRSS3 have not yet been described in association with mid-frequency SNHL. In eight additional probands, eight candidate VUS variants were detected in five genes (DIAPH1, MYO7A, TECTA, TMC1, TSPEAR). Seven of these 16 variants have not yet been published or mentioned in the available databases. The most prevalent gene was TECTA, identified in 23% of all tested families. Furthermore, we confirmed the hypothesis that a substantive portion of cases with this conspicuous audiogram shape is a consequence of a genetic disorder.
| S-EPMC8602250 | biostudies-literature
Project description:The etiology behind cancer-related fatigue (CRF) is currently unknown. The physiological mechanisms of CRF are based on limited evidence that genetic factors, energy expenditure, metabolism, aerobic capacity, and the individual's immune response to inflammation are responsible for the experience of CRF. Gene expression profiling using microarray analysis from white blood cells of men with non-metastatic prostate cancer shows significant, differential expression of 463 probesets during localized external beam radiation therapy (EBRT). Pathway analysis shows a central role of SNCA (alpha-synuclein gene) among these differentially expressed probesets. Significant expression of SNCA was confirmed by qPCR (p<.001) and ELISA (p<.001) over time during EBRT. A significant correlation was noted between averaged fatigue scores and delta CT values of SNCA expression using confirmatory qPCR over time during EBRT (R=-.90, p=.006). Development of fatigue experienced by these men during EBRT may be mediated by SNCA expression. Pathways related to alpha-synuclein may serve as useful biomarkers to understand the mechanisms behind the development of fatigue.
2012-12-21 | GSE30174 | GEO
Project description:Mitochondrial DNA copy number (mtCN) is often treated as a proxy for mitochondrial (dys-) function and disease risk. Pathological changes in mtCN are common symptoms of rare mitochondrial disorders, but reported associations between mtCN and common diseases vary across studies. To understand the biology of mtCN, we carried out genome- and phenome-wide association studies of mtCN in 30,666 individuals from the Penn Medicine BioBank (PMBB)-a diverse cohort of largely African and European ancestry. We estimated mtCN in peripheral blood using exome sequence data, taking cell composition into account. We replicated known genetic associations of mtCN in the PMBB and found that their effects are highly correlated between individuals of European and African ancestry. However, the heritability of mtCN was much higher among individuals of largely African ancestry (h2=0.3) compared with European ancestry individuals(h2=0.1). Admixture mapping suggests that there are undiscovered variants underlying mtCN that are differentiated in frequency between individuals with African and European ancestry. We show that mtCN is associated with many health-related phenotypes. We discovered robust associations between mtDNA copy number and diseases of metabolically active tissues, such as cardiovascular disease and liver damage, that were consistent across African and European ancestry individuals. Other associations, such as epilepsy and prostate cancer, were only discovered in either individuals with European or African ancestry but not both. We show that mtCN-phenotype associations can be sensitive to blood cell composition and environmental modifiers, explaining why such associations are inconsistent across studies. Thus, mtCN-phenotype associations must be interpreted with care.
| S-EPMC10225932 | biostudies-literature
Project description:Genetic alterations identified in adjacent normal appearing tissue in bladder cancer patients are indicative of a field disease. Here we assessed normal urothelium transformation and intra-tumour heterogeneity (ITH) in four patients with bladder cancer. Exome sequencing identified private acquired mutations in a lymph node metastasis and local recurrences. Deep re-sequencing revealed presence of at least three and four subclones in two patients with multifocal disease, while no demarcation of subclones was identified in the two patients with unifocal disease. Analysis of adjacent normal urothelium showed low frequency mutations in patients with multifocal disease. Expression profiling showed intra-tumour and intra-patient co-existence of basal- and luminal-like tumour regions, and patients with multifocal disease had a greater degree of genomic and transcriptomic ITH, as well as transformation of adjacent normal cells, compared to patients with unifocal disease. Analysis of the adjacent urothelium may pave the way for therapies targeting the field disease.
| S-EPMC5600970 | biostudies-literature
Project description:BackgroundProstate cancer (PrCa) is one of the most genetically driven solid cancers with heritability estimates as high as 57%. Men of African ancestry are at an increased risk of PrCa; however, current polygenic risk score (PRS) models are based on European ancestry groups and may not be broadly applicable. The objective of this study was to construct an African ancestry-specific PrCa PRS (PRState) and evaluate its performance.MethodsAfrican ancestry group of 4,533 individuals in ELLIPSE consortium was used for discovery of African ancestry-specific PrCa SNPs. PRState was constructed as weighted sum of genotypes and effect sizes from genome-wide association study (GWAS) of PrCa in African ancestry group. Performance was evaluated using ROC-AUC analysis.ResultsWe identified African ancestry-specific PrCa risk loci on chromosomes 3, 8, and 11 and constructed a polygenic risk score (PRS) from 10 African ancestry-specific PrCa risk SNPs, achieving an AUC of 0.61 [0.60-0.63] and 0.65 [0.64-0.67], when combined with age and family history. Performance dropped significantly when using ancestry-mismatched PRS models but remained comparable when using trans-ancestry models. Importantly, we validated the PRState score in the Million Veteran Program (MVP), demonstrating improved prediction of PrCa and metastatic PrCa in individuals of African ancestry.ConclusionsAfrican ancestry-specific PRState improves PrCa prediction in African ancestry groups in ELLIPSE consortium and MVP. This study underscores the need for inclusion of individuals of African ancestry in gene variant discovery to optimize PRSs and identifies African ancestry-specific variants for use in future studies.
| S-EPMC9733391 | biostudies-literature
Project description:Triple negative breast cancers (TNBCs) are molecularly heterogeneous, and the link between their aggressiveness with African ancestry is not established. We investigated primary TNBCs for gene expression among self-reported race (SRR) groups of African American (AA, n = 42) and European American (EA, n = 33) women. RNA sequencing data were analyzed to measure changes in genome-wide expression, and we utilized logistic regressions to identify ancestry-associated gene expression signatures. Using SNVs identified from our RNA sequencing data, global ancestry was estimated. We identified 156 African ancestry-associated genes and found that, compared to SRR, quantitative genetic analysis was a more robust method to identify racial/ethnic-specific genes that were differentially expressed. A subset of African ancestry-specific genes that were upregulated in TNBCs of our AA patients were validated in TCGA data. In AA patients, there was a higher incidence of basal-like two tumors and altered TP53, NFB1, and AKT pathways. The distinct distribution of TNBC subtypes and altered oncologic pathways show that the ethnic variations in TNBCs are driven by shared genetic ancestry. Thus, to appreciate the molecular diversity of TNBCs, tumors from patients of various ancestral origins should be evaluated.
| S-EPMC7281131 | biostudies-literature