Search Results - EGA European Genome-Phenome Archive

Using Genomics to Reduce Breast Cancer Disparities in the African Diaspora

Differences in breast cancer incidence and mortality rates between North American Caucasian and African American women are well-described and transcend socioeconomic issues. Black women are diagnosed with breast cancer at a younger median age; have more clinically aggressive disease and stage-for-stage; and have higher mortality rates than age-matched Caucasian women. Black women in West Africa, the origin of the slave trade in the US in the 19th century and thus the founder population for most African Americans, have even higher rates of early-onset, poor-prognosis breast cancer than African American women. Racial difference in the distribution of intrinsic molecular subtypes has been well characterized in the US and throughout the African Diaspora as well. Despite the large efforts on characterizing racial/ethnic differences, however, the reasons women of African ancestry are disproportionately affected by breast cancer incidence and mortality remain poorly understood - largely due to paucity of data on inherent genomic differences that contribute to the disparities in incidence and progression of breast cancer across populations. West Africa Breast Cancer Study (WABCS) is an initiative that aims to comprehensively understand the genetic architecture of breast cancer in West Africans, the founder population of a large proportion of black women in the United States. The objective of the study was to provide a better understanding of the molecular genetic factors that influence prognosis in Nigerian breast cancer patients, and determine which of these alterations may be amenable to available therapy. To that end, we examined the molecular features of breast cancers of indigenous African women using a combination of whole-genome, whole-exome, and transcriptome sequencing (WGS, WES, and RNA-seq) on 194 tumors from Nigerian patients. The goal of this project was to obtain answers to two related research questions using an unscreened population without genetic admixture in Nigeria: 1) why are women of African ancestry more likely to develop aggressive young onset breast cancer? 2) What are the associated genomic and non-genomic risk factors? We hypothesize that the genomic determinants of breast cancer molecular subtypes in women of African ancestry are also molecular drivers of tumor progression and represent targets for interventions to improve clinical outcomes and close the mortality gap. By identifying causal links between genetic variants that promote aggressive tumor progression in Nigerian women in comparison to women from different population found in TCGA and ICGC, the present dataset will have significant public health impact on millions of women in the African Diaspora. The potential to identify novel pathways for interventions to reduce the increasing mortality gap between women of African and European ancestry is huge

Study phs001687

Shanghai Breast Cancer Genetics Study (SBCGS)

The Shanghai Breast Cancer Genetics Study (SBCGS) includes data from four population-based studies conducted among Chinese women in urban Shanghai: the Shanghai Breast Cancer Study (SBCS), the Shanghai Breast Cancer Survival Study (SBCSS), the Shanghai Women's Health Study (SWHS), and the Shanghai Endometrial Cancer Study (SECS, contributing controls only). Shanghai Breast Cancer Study (SBCS): The SBCS is a population-based, case-control study conducted in urban Shanghai. Subject recruitment in the initial phase of the SBCS (SBCS-I) was conducted between August 1996 and March 1998. The second phase (SBCS-II) of recruitment occurred between April 2002 and February 2005. Breast cancer cases were identified through the population-based Shanghai Cancer Registry and supplemented by a rapid case-ascertainment system. Controls were randomly selected using the Shanghai Resident Registry. Approximately 3500 cases and 3500 controls were recruited in the study. Shanghai Breast Cancer Survival Study (SBCSS) and Shanghai Endometrial Cancer Study (SECS): The SBCSS also used the population-based Shanghai Cancer Registry to identify newly diagnosed breast cancer cases. A total of 5,046 breast cancer patients were recruited. In-person interviews were conducted to collect information on known breast cancer risk factors and anthropometrics by using a protocol and questionnaire similar to those used in the SBCS. For genetic studies, controls for the SBCSS cases came from the SECS, which recruited healthy women between January 1997 and December 2003. With the exception of a few questions related specifically to breast or endometrial cancer risk, the questionnaires used in the SECS and the SBCS were very similar. Shanghai Women's Health Study (SWHS): The SWHS is a population-based prospective cohort study of approximately 75,000 adult women who were recruited between 1997 and 2000. The cohort has been followed by a combination of record linkage and active follow-ups. Breast cancer patients identified in the SWHS and non-cases were included in the current study.

Study phs000799

Methylation biomarker study of magnesium deficiency and colorectal cancer

Five US studies using the Mg tolerance test, the "gold standard" test of Mg status, indicated that >50% participants had Mg deficiency. In our ongoing US trial, we have found a similar result. In growing recognition of the importance of Mg in human health, very recently, Mg was selected by the US Federal Dietary Reference Intake (DRI) Committee to update the DRI. In US and other populations at high risk of Mg deficiency, high Mg intake has been linked to reduced risk of colorectal neoplasia, insulin resistance, metabolic syndrome, type 2 diabetes, and cardiovascular disease (CVD). Conversely, in populations not at high risk of Mg deficiency, high Mg intake has been related to increased risk of total mortality (e.g. total cancer, colorectal cancer, and CVD), particularly when calcium intake is low. These observations suggest that the associations between high Mg intake and disease risks may completely differ by the underlying Mg status. Due to major limitations, the Mg tolerance test is not used in conventional clinical practice and rarely used in research. Instead, serum Mg is used for clinical diagnosis. However, serum Mg performs very poorly at identifying those with Mg deficiency. There is a great need to develop implementable, sensitive, and specific biomarkers which can be easily used for identifying people with Mg deficiency. Without such a marker, it is impossible to develop effective strategies that minimize adverse effects by targeting those who, as a result of Mg deficiency, are at risk of common diseases. It is known that DNA methylation changes are inducible by environmental exposures, including nutrients, and reversible when the exposure disappears. There are two major types of cytosine modifications in DNA, 5-hydroxymethylcytosine (5-hmC) and 5-methylcytosine (5-mC). 5-mC is often associated with suppressed gene expression. 5-hmC, generated by the oxidation of 5-mC, is specifically enriched in expressed genes and plays a critical role in activating and/or maintaining gene expression. However, current epigenomic profiling platforms cannot distinguish 5-hmC from 5-mC. Just recently, our collaborator, Dr. Chuan He (HHMI Investigator), established a novel and state of the art technique, TAB-Seq and TAB-Array protocol, which can separate 5-hmC from 5-mC in the genome. Our pilot studies indicate that Mg intake or treatment significantly affects methylation capacity, 5-mC and 5-hmC biomarkers. Our findings suggest blood leukocyte 5-hmC/5-mC biomarkers may serve as more sensitive biomarkers to identify Mg deficiency than serum Mg. Thus, a comprehensive epigenome-wide association study (EWAS) may help to identify the most sensitive 5-hmC/ 5- mC biomarkers for Mg deficiency. We propose to identify 5-hmC/5-mC biomarkers for Mg deficiency by a 4- phase EWAS study in the "Personalized Prevention of Colorectal Cancer Trial [PPCCT, R01CA149633; PI, Dai and Yu]" with a total of 240 participants. Mg tolerance test will be used as the gold standard. Finally, using newly identified biomarkers, we will evaluate if 12-week Mg treatment reduces TRPM7 expression, essential in Mg homeostasis and colorectal carcinogenesis, in rectal tissues only among those with Mg deficiency.

Study phs002037

Preclinical Modeling of Leiomyosarcoma Identifies Susceptibility to Transcriptional CDK Inhibitors through Antagonism of E2F-Driven Oncogenic Gene Expression

Leiomyosarcoma (LMS) is a smooth muscle-derived mesenchymal cancer commonly found to have recurrent loss of tumor suppressor genes and a poorly defined oncogenic program. Empiric cytotoxic chemotherapy is the standard systemic treatment for LMS, and while more targeted and effective therapies are urgently needed, insights into therapeutic vulnerabilities in LMS have been limited by available preclinical models. We generated a panel of LMS patient-derived xenograft (PDX) models and evaluated fidelity to their tumors of origin using RNA sequencing and ultra-low passage whole-genome sequencing (ULP-WGS). Data available at dbGaP include RNA sequencing and ULP-WGS of primary tumors and early and late passages of PDX. 

Study phs002587

Genomics of Pediatric Renal Medullary Carcinomas

Version 1We derived faithful cancer cell lines from patients with a diagnosis of renal medullary carcinomas (RMC). These models have been sequenced with whole genome, exome and transcriptome technologies along with the patient's primary germline and tumor samples. We took these faithful models and performed loss-of-function genetic perturbation screens (e.g. RNAi and CRISPR-Cas9) along with an orthogonal small molecule screen. We identified the ubiquitin-proteasome system as an important target in RMC as well as other SMARCB1 deficient cancers.Version 2We have collaborated with the Children's Oncology Group and the study AREN03B2 to study the cohort of patients with a central diagnosis of RMC. Here, we used 10x linked read sequencing along with RNA-sequencing to profile these matched tumor-normal pairs.

Study phs001800

A Pilot Study of Rapid Autopsy and Procurement of Tissue in Thoracic Malignancy Cancer Patients to Investigate Tumor Heterogeneity

Integrated proteo-genomics studies to characterize tumor heterogeneity of metastatic lung adenocarcinoma and thymic carcinoma are lacking. We carried out whole exome sequencing, RNA sequencing, copy number estimation and mass spectrometry-based proteomics of 40 tumors from five rapid/warm autopsy patients. We found highly variable mutational heterogeneity that was largely driven by APOBEC-mutagenesis with the expression of APOBEC3B (Gene ID: 9582) and APOBEC3A_B (Gene ID: 100913187) due to underlying APOBEC3 region germline variants as the likely mediating mechanism. APOBEC3A_B expression was associated with increased immune tumor microenvironment and CD274 (Gene ID: 29126) expression while smoking was associated with increased APOBEC-mutagenesis in TP53 (Gene ID: 7157) mutant tumors with high APOBEC3B expression. Heterogeneity at the level of the transcriptome and proteome occurred in association with copy number heterogeneity, not APOBEC-induced mutational heterogeneity. Arm and focal copy number alterations (CNAs) occurred as an evolutionarily late event in a subset of patients, with corresponding changes in the transcriptome and proteome, implicating CNAs as a driving force of heterogeneity in the evolution of metastatic disease.

Study phs001432

A Pilot Study Using Next Generation Sequencing in Advanced Cancers: Feasibility and Challenges

In this study, we used NGS to identify somatic events in advanced stage cancer patients to demonstrate the feasibility for using this approach to improve patient treatment.

Study phs000657

Multiregion Sequencing of Localized Prostate Cancer

Ten patients with treatment-naïve, locally advanced or localized prostate cancer underwent radical prostatectomy. Pathological stage ranged from T2aN0 to T3bN1, and Gleason scores from 3+4 to 4+5. Tumor foci were mapped, and DNA was extracted from multiple (5-9) regions from a single, contiguous index focus. Whole exome sequencing was performed to identify single nucleotide variants and indels, and low coverage whole genome sequencing was performed to estimate copy number variation. Phylogenetic relationships between foci was determined, and alterations associated with advanced disease or response to targeted therapy were identified.

Study phs001465

Phase IB/II Study of Bazedoxifene in Combination with Palbociclib in Patients with Endocrine Resistant Hormone Receptor-Positive Breast Cancer

In this phase Ib/II clinical trial, the investigators evaluated the efficacy and safety of the combination of palbociclib with bazedoxifene in patients with a metastatic endocrine-resistant hormone receptor-positive, HER2-negative breast cancer. Furthermore, whole exome sequencing of cell-free tumor DNA was done on serial samples from these patients, revealing potential molecular changes associated with mechanisms of resistance.

Study phs002802

Childhood Cancer Data Initiative (CCDI): Clonal Evolution During Metastatic Spread in High-Risk Neuroblastoma

The goal of this study is to deliver a detailed characterization of the patterns of disease dissemination at diagnosis, during progression and in response to therapy in high-risk neuroblastoma. Longitudinal and spatially distinct tumors were collected from patients. Clinical data includes diagnosis and treatment information. Biospecimen data includes whole genome sequencing (WGS) and whole transcriptome sequencing (WTS).

Study phs003111

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