Project description:The incidence and mortality rates of prostate cancer are significantly higher in African-American men when compared to European-American men. We tested the hypothesis that differences in tumor biology contribute to this survival health disparity. Using microarray technology, we obtained gene expression profiles of primary prostate tumors resected from 33 African-American and 36 European-American patients. These tumors were matched on clinical parameters. We also evaluated 18 non-tumor prostate tissues from 7 African-American and 11 European-American patients. The resulting datasets were analyzed for expression differences on the gene and pathway level comparing African-American with European-American patients. Our analysis revealed a significant number of genes, e.g., 162 transcripts at a false-discovery rate less than 5%, to be differently expressed between African-American and European-American patients. Using a disease association analysis, we identified a common relationship of these transcripts with autoimmunity and inflammation. These findings were corroborated on the pathway level with numerous differently expressed genes clustering in immune response, stress response, cytokine signaling, and chemotaxis pathways. Furthermore, a two-gene tumor signature was identified that accurately differentiated between African-American and European-American patients. This finding was confirmed in a blinded analysis of a second sample set. In conclusion, the gene expression profiles of prostate tumors indicate prominent differences in tumor immunobiology between African-American and European-American men. The profiles portray the existence of a distinct tumor microenvironment in these two patient groups. Keywords: Microdissected tissue analysis
Project description:The incidence and mortality rates of prostate cancer are significantly higher in African-American men when compared to European-American men. We tested the hypothesis that differences in tumor biology contribute to this survival health disparity. Using microarray technology, we obtained gene expression profiles of primary prostate tumors resected from 33 African-American and 36 European-American patients. These tumors were matched on clinical parameters. We also evaluated 18 non-tumor prostate tissues from 7 African-American and 11 European-American patients. The resulting datasets were analyzed for expression differences on the gene and pathway level comparing African-American with European-American patients. Our analysis revealed a significant number of genes, e.g., 162 transcripts at a false-discovery rate less than 5%, to be differently expressed between African-American and European-American patients. Using a disease association analysis, we identified a common relationship of these transcripts with autoimmunity and inflammation. These findings were corroborated on the pathway level with numerous differently expressed genes clustering in immune response, stress response, cytokine signaling, and chemotaxis pathways. Furthermore, a two-gene tumor signature was identified that accurately differentiated between African-American and European-American patients. This finding was confirmed in a blinded analysis of a second sample set. In conclusion, the gene expression profiles of prostate tumors indicate prominent differences in tumor immunobiology between African-American and European-American men. The profiles portray the existence of a distinct tumor microenvironment in these two patient groups. Experiment Overall Design: A total of 69 fresh-frozen prostate tumors were obtained from the NCI Cooperative Prostate Cancer Tissue Resource (CPCTR) and the Department of Pathology at the University of Maryland (UMD). All tumors were resected adenocarcinomas that had not received any therapy prior to prostatectomy. The macro-dissected CPCTR tumor specimens (n = 59) were reviewed by a CPCTR-associated pathologist, who confirmed the presence of tumor in the specimens. These tissues were collected between 2002 and 2004 at four different sites, with each site providing tissues from both African-American and European-American patients. Information on race/ethnicity (33 African-Americans and 36 European-Americans) was either extracted from medical records (CPCTR) or obtained through an epidemiological questionnaire in which race/ethnicity was self-reported (UMD). Only one patient, a European-American, was also Hispanic. Surrounding non-tumor prostate tissue was collected from 18 of the recruited patients in this study. Of those, 7 were African-American men and 11 were European-American men. We also isolated total RNA from 10 needle biopsy specimens collected from patients at the National Naval Medical Center (one African-American and 9 European-Americans) that did not have prostate cancer. From those, we prepared two RNA pools, each representing 5 patients. Clinicopathological characteristics of the patients, including age at prostatectomy, histology, Gleason score, pathological stage, PSA at diagnosis, tumor size, extraprostatic extension, margin involvement, and seminal vesicle invasion were obtained from CPCTR. For UMD cases, this information was extracted from the medical and pathology records, if available. Written informed consent was obtained from all donors. Tissue collection and study design were approved by the institutional review boards of the participating institutions.
Project description:We use androgen receptor chromatin immunoprecipitation (AR ChIP) on frozen prostate adenocarcinoma samples and normal prostate counterparts in men of European ancestry as well as men of African (AA) ancestry and derive a model whereby increased androgen signaling drives higher levels of lipogenesis in AA prostate tumors.
Project description:We use androgen receptor chromatin immunoprecipitation (AR ChIP) on frozen prostate adenocarcinoma samples and normal prostate counterparts in men of European ancestry as well as men of African (AA) ancestry and derive a model whereby increased androgen signaling drives higher levels of lipogenesis in AA prostate tumors.
Project description:African-American (AA) men experience increased risk of developing prostate cancers as well as increased mortality following treatment as compared to European-American (EA) men. The aim of our study was to identify biological factors with potential to predispose AA men to prostate tumor progression and metastasis. High-throughput microarrays were used to investigate differences in global gene expression comparing the two groups.
Project description:African-American (AA) men experience increased risk of developing prostate cancers as well as increased mortality following treatment as compared to European-American (EA) men. The aim of our study was to identify biological factors with potential to predispose AA men to prostate tumor progression and metastasis. High-throughput microarrays were used to investigate differences in global gene expression comparing the two groups. Experiment Overall Design: To identify cancer-specific gene expression patterns in AA men, we established primary prostate cancer epithelial cells from 14 AA and 13 EA men. Cells were cultured for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Men with African ancestry have the highest incidence and mortality rates of prostate cancer (PCa) worldwide. This study aimed to identify differentially methylated genes between tumor vs. adjacent normal and aggressive vs. indolent PCa in 121 African American patients. Epigenome-wide DNA methylation patterns in tumor DNA were assessed using the human Illumina Methylation EPIC V1 array. Around 5,139 differentially methylated CpG-sites (q<0.01, lΔβl>0.2) were identified when comparing normal vs. tumor, with an overall trend of hypermethylation in prostate tumors. Multiple representatives differentially methylated regions (DMRs), including immune-related genes, such as CD40, Galectin3, OX40L, and STING, were detected in prostate tumors when compared to adjacent normal tissues. Based on an epigenetic clock model, we observed that tumors' total number of stem cell divisions and the stem cell division rate were significantly higher than adjacent normal tissues. Regarding aggressiveness, 2,061 differentially methylated CpG-sites (q<0.05, lΔβl>0.05) were identified when the grade group (GG)1 was compared with GG4/5. Among these 2,061 CpG sites, 155 probes were consistently significant in more than one comparison. Among these genes, several immune system genes, such as COL18A1, S100A2, ITGA4, HLA-C, and ADCYAP1, have previously been linked to tumor progression in PCa. Several differentially methylated genes involved in immune-oncologic pathways associated with disease risk or aggressiveness were identified. In addition, 261 African American-specific differentially methylated genes related to the risk of PCa were identified. These results can shed light on potential mechanisms contributing to PCa disparities in the African American population.
Project description:Gene expression characteristics of primary prostate cancer tumors from African-Americans are substantially different as compared to European-American men
Project description:Here we report the establishment and characterization of a Prostate Cancer Patient Derived Explant (PCPDX) from a patient of West African ancestry with metastatic castration resistant disease. The following data represents gene expression in a series of mice carrying this PCPDX and undergoing different treatment courses. Mice were treated for 10 weeks with either Enzalutamide, Cisplatin, or Docetaxel, or appropriate vehicle controls.
Project description:Prostate cancer is one of the most prevalent cancers worldwide, particularly affecting men living a western lifestyle and of African descent, suggesting risk factors that are genetic, environmental, and socioeconomic in nature. In the USA, African American (AA) men are disproportionately af-fected, on average suffering from a higher grade of the disease and at a younger age compared to men of European descent (EA). Fusion genes are chimeric products formed by the merging of two separate genes occurring as a result of chromosomal structural changes, for example, inversion or trans/cis-splicing of neighboring genes. They are known drivers of cancer and have been identified in 20% of cancers. Improvements in genomics technologies such as RNA-sequencing coupled with better algorithms for prediction of fusion genes has added to our knowledge of specific gene fu-sions in cancers. At present AA are underrepresented in genomic studies of prostate cancer. The primary goal of this study was to examine molecular differences in predicted fusion genes in a cohort of AA and EA men in the context of prostate cancer using computational approaches. RNA was purified from prostate tissue specimens obtained at surgery from subjects enrolled in the study. Fusion gene predictions were performed using four different fusion gene detection pro-grams. This identified novel putative gene fusions unique to AA and suggested that the fusion gene burden was higher in AA compared to EA men.