Project description:Women of sub-Saharan African descent have disproportionately higher incidence of Triple Negative Breast Cancer (TNBC), and TNBC-specific mortality. Population comparative studies show racial differences in TNBC biology, including higher prevalence of basal-like and Quadruple-Negative subtypes in African Americans (AA). However, previous investigations relied on self-reported race (SRR) of primarily United States (US) populations. Due to heterogenous genetic admixture, and biological consequences of social determinants, the true association of African ancestry with TNBC biology is unclear. To address this, we conducted RNAseq on an international cohort of AAs, west and east Africans with TNBC. Using comprehensive genetic ancestry estimation in this African-enriched cohort, we found expression of 613 genes associated with African ancestry and 2000+ associated with regional African ancestry. A subset of African-associated genes also showed differences in normal breast tissue. Pathway enrichment and deconvolution of tumor cellular composition revealed tumor-associated immunological profiles are distinct in patients of African descent.
Project description:Study of genes that are differentially spliced and differentially expressed between African Americans and whites with lung squamous cell cancer. Despite racial disparities in lung cancer, the molecular landscape of lung cancer in patients of African ancestry remains underexplored. Population-related differences in alternative RNA splicing have not been explored. We identified differentially spliced genes and differentially expressed genes between lung squamous cell carcinoma from patients of West African and European ancestry.
Project description:The genomic and immune landscapes of prostate cancer differ by self-identified race. However, few studies have examined the genome-wide copy number landscape and immune content of matched cohorts with genetic ancestry data and clinical outcomes. Here, we assessed prostate cancer somatic copy number alterations (sCNA) and tumor immune content of a grade-matched, surgically-treated cohort of 145 self-identified Black (BL) and 145 self-identified white (WH) patients with genetic ancestry estimation. A generalized linear model adjusted with age, pre-operative PSA, and Grade Group and filtered for germline copy number variations (gCNV) identified 143 loci where copy number varied significantly by percent African ancestry, clustering on chromosomes 6p, 10q, 11p, 12p, and 17p. Multivariable Cox regression models adjusted for age, pre-operative PSA levels, and Grade Group revealed that chromosome 8q gains (including MYC) were significantly associated with biochemical recurrence and metastasis, independent of genetic ancestry. Finally, regulatory T-cell density in BL and WH patients was significantly correlated with percent genome altered, and these findings were validated in the TCGA cohort. Taken together, our findings identify specific sCNA linked to genetic ancestry and outcome in primary prostate cancer and demonstrate that regulatory T-cell infiltrate varies by global sCNA burden in primary disease.
Project description:Characterization of ancestry-linked peptide variants in disease-relevant patient tissues represents a foundational step to connect patient ancestry with molecular disease pathogenesis. Nonsynonymous single nucleotide polymorphisms (SNPs) encoding missense substitutions within tryptic peptides exhibiting high allele frequencies in European, African, and East Asian populations, termed peptide ancestry informative markers (pAIMs), were prioritized from 1000 genomes. In silico analysis shows that as few as 20 pAIMs can determine ancestry proportions similarly to >260K SNPs (R2=0.9905). Multiplexed proteomic analysis of >100 human endometrial cancer cell lines and uterine leiomyoma (ULM) tissues combined resulted in the quantitation of 62 pAIMs that correlate with self-described race and genotype-confirmed patient ancestry. Candidates include a D451E substitution in GC vitamin D-binding protein previously associated with altered vitamin D levels in African and European populations. These efforts describe a generalized set of markers for proteoancestry assessment that will further support studies investigating the impact of ancestry on the human proteome and how this relates to the pathogenesis of uterine neoplasms.
Project description:<p>The paucity of data on the genetic epidemiology of breast cancer for racial/ethnic groups other than those of European ancestry hinders the development of innovative interventions to reduce health disparities. Women in the African Diaspora experience a disproportionate burden of pre-menopausal breast cancer in comparison to all other races for reasons that remain unknown and understudied. This higher proportion of early-onset breast cancer might suggest a stronger genetic component in these populations. Genome-wide association studies (GWAS) have revealed several genetic loci that confer risk of breast cancer. Because all GWAS started the discovery stage in women of European ancestry and replicated mainly in women of European ancestry, we propose a novel approach for a GWAS in indigenous African women to identify alleles associated with breast cancer risk which will then be replicated in other populations. This innovative design builds on our current understanding of the etiologic heterogeneity in breast cancer and the distribution of breast cancer molecular subtypes which differ between women of African ancestry and women of European ancestry. The major objective of the proposed studies is to get to the "root" causes of breast cancer by identifying breast cancer risk alleles in a pooled sample of women of African ancestry and to replicate our findings in other populations.</p> <p>To achieve this objective, we conducted a case control study of breast cancer in women of African ancestry, including Africans living in Nigeria, African Americans and African Barbadians. We will genotype ~3800 individuals using the Illumina HumanOmni2.5-Quad platform. We will conduct both standard and novel genetic analyses of the data to map genes associated with breast cancer susceptibility, verify genotyping and carry out fine-mapping studies in genes or regions showing association with breast cancer risk, and replicate in other African American and non-African American populations. By pooling unique resources from studies throughout the African Diaspora, this study has the potential to identify risk alleles in several genes that contribute to increased breast cancer risk and may have implications for early detection, prognosis and treatment of breast cancer in ALL women. This should ultimately lead to improved outcomes for those who suffer a disproportionate burden of early-onset breast cancer.</p>
Project description:Background: Mortality from preeclampsia (PE) and PE-associated morbidities are 3-to 5-fold higher in persons of African ancestry than in those of Asian and European ancestries. The placenta is central to the etiology of PE. However, how and to what extent the placenta contributes to worse PE outcomes in persons of African ancestry is yet to be fully elucidated. Objective: We aimed to identify molecular pathways that are unique or enriched in placentas of parturient persons of African ancestry with PE with severe features (sPE) compared to those of Asian and European ancestry with sPE. Study design: Bulk RNA sequencing was performed on 50 placentas from parturient persons with sPE of African (n=9), Asian (n=18) and European (n=23) ancestries and 73 normotensive controls of African (n=9), Asian (n=15) and European (n=49) ancestries. Results: Metabolism, hormone regulation and hypoxia/angiogenesis genes, previously described to be upregulated in PE, including: LEP, PAPPA2, INHA, FSTL3, FLT1, PHYHIP and ENG, were upregulated in sPE across ancestries, with high expression of FSTL3 being additionally associated with intrauterine growth restriction (p<.0001). Notably, LEP, FLT1 and PHYHIP were more highly upregulated in sPE placentas from parturient persons of African versus Asian ancestry. Genes associated with allograft rejection and adaptive immune response were selectively upregulated in placentas from African ancestry parturitions and not in those of Asian and European ancestries. Among the allograft rejection/adaptive immune response genes, IL3RA was of particular interest because the patient with the highest placental IL3RA level, a woman of African ancestry with IL3RA levels 4.5-fold above the average for African ancestry parturitions with sPE, developed postpartum cardiomyopathy, and was the only patient out of 123, that developed this condition. Interestingly, the sPE patients of Asian and European ancestries with the highest IL3RA levels for their ancestries developed unexplained tachycardia peripartum, necessitating echocardiography in the European ancestry patient. The association between elevated placental IL3RA levels and unexplained tachycardia or peripartum cardiomyopathy was found to be significant in the 50 sPE patients (p=.0005). Conclusions: African ancestry parturitions are associated with higher placental upregulation of metabolism (LEP) and hypoxia/angiogenesis (FLT1) genes, and selective upregulation of allograft rejection/adaptive immune response genes, including IL3RA. High placental expression of IL3RA may predict worse maternal cardiovascular outcomes, including peripartum cardiomyopathy. Studies evaluating placental IL3RA levels in peripartum cardiomyopathy cohorts are therefore warranted, as are broader studies evaluating placental factors in maternal cardiovascular outcomes postpartum.
Project description:Individuals from different populations vary considerably in their susceptibility to immune-related diseases. To understand how genetic variation and natural selection contribute to these differences, we tested for the effects of African versus European ancestry on the transcriptional response of primary macrophages to live bacterial pathogens. 12% of macrophage-expressed genes show ancestry-associated differences in the gene regulatory response to infection, and African ancestry specifically predicts a stronger inflammatory response and reduced intracellular bacterial growth. A large proportion of these differences are under genetic control: for 569 genes, more than 75% of ancestry effects on the immune response can be explained by a single cis- or trans-acting eQTL. Finally, we show that genetic effects on the immune response are strongly enriched for recent, population-specific signatures of adaptation. Together, our results demonstrate how historical selective events continue to shape human phenotypic diversity today, including for traits that are central to coping with infection. Transcriptomic profiles of 503 infected (Listeria and Salmonella) and non-infected samples at 2hr time point.
Project description:Differences in microRNAs have not been well studied as potential mechanisms underlying the breast cancer disparity. A number of miRNAs were differentially expressed not only by tumor subtype but by ancestry, indicating differences in tumor biology of breast cancer between women of African and European ancestry. Findings may contribute to a better understanding of the biology of breast cancer disparities and help develop more targeted preventative and therapeutic strategies.