Expression data from prostate cancer epithelial cells from African American and European American men
ABSTRACT: 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. 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.
INSTRUMENT(S): [HG-U133A_2] Affymetrix Human Genome U133A 2.0 Array
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:African-American (AA) men have a higher risk of lethal prostate cancer (PCa) compared to European-American (EA) men. However, the molecular basis of this difference, if any, remains unclear. In EA PCa, PTEN loss, but not ERG rearrangement, has been associated with poor outcomes in most studies. Although ERG rearrangement is less common in AA compared to EA PCa, the relative frequency of PTEN loss and the association of PTEN/ERG molecular subtypes with outcomes is unknown for AA PCa. We examined PTEN/ERG status by immunohistochemistry in self-identified AA patients undergoing radical prostatectomy at Johns Hopkins with tumor tissue available on tissue microarray (TMA; n=169) and matched these cases by pathologic parameters to 169 EA patients from the same TMAs. The rate of PTEN loss was significantly lower in AA compared to EA PCa (18% vs 34%; p=0.001), similar to the lower rate of ERG expression (25% vs 51%; p<0.001). To examine the association of PTEN/ERG status with oncologic outcomes, we created an additional TMA of 87 AA tumors with Gleason score > 4 + 3 = 7. Among the total population of AA men with outcome data from all TMAs (n=222), PTEN loss was associated with higher risk of biochemical recurrence (hazard ratio [HR] 2.25, 95% confidence interval [CI] 1.33-3.82) and metastasis (HR 3.90, 95% CI 1.46-10.4) in multivariable models.PTEN and ERG alterations in prostate cancer are less likely in African-American than in European-American men. However, PTEN loss remains associated with poor prostate cancer outcomes among African-American men.
Project description:African American (AA) men have a significantly higher mortality rate from prostate cancer (PCa) compared to European American (EA) men. AA men are twice as likely to die from PCa compared to EA men and 8 times as likely as Asian American men to die from PCa. The biological basis for these differences in PCa mortality are unclear. We carried out Copy Number Alteration (CNA) studies on a new set of 40 highly tumor-enriched primary PCas and matched benign prostate tissues from AA men using high resolution Affymetrix 6.0 SNP arrays and expression array analysis using RNAs (GSE71016) from the same tissues using high purity tumors from AA men and matched benign tissue. We have confirmed the specific loss of 4p16.3 described previously and identified a novel tumor suppressor gene, RGS12 at this locus that shows significantly decreased expression in AA PCa but not EA EA PCa. Overall design: Profiles were generated on Affymetrix SNP 6.0 chips. In all, 40 tumors and 40 paired normal samples were profiled, 40 profiles in all. Each tumor was centered on its corresponding normal pair to define copy number alterations (CNA) in that tumor.
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. Overall design: Fusion Genes in Prostate Cancer: A Comparison in Men of African and European Descent
Project description:African-American (AA) men have both a higher incidence and significantly higher mortality rates from prostate cancer (PCa) than European American (EA) men. In this study we have carried out a detailed analysis of both CNAs and gene expression changes in PCas from AA men compared to their matched benign tissues. We have identified MNX1 as a novel androgen regulated oncogene that is upregulated to a greater degree in AA PCa compared to EA PCa. Furthermore, RGS12 is a novel tumor suppressor on 4p16.3 that is preferentially deleted in AA PCa which negatively regulates MNX1 expression. Overall design: In this study we have carried out a detailed analysis of gene expression changes in PCas from AA men compared to their matched benign tissues. two-group comparison
Project description:Prostate cancer (PCa) tends to be more aggressive and lethal in African Americans (AA) compared to European Americans (EA). To further understand the thebiological risk factors associated with PCa disparities observed in AA and EA patients, we performed microRNA profiling using Agilent Human miRNA arrays to identify the differentially expressed microRNAs beween: 1) AA and EA PCa patients; 2) AA PCa vs. AA normal; and 3) EA PCa vs. EA normal. 54 prostate biopsy specimens (tumor and adjacent normal tissues) were collected from 14 African American and 13 European American prostate cancer patients. 54 RNA samples, purified from the collected biopy specimens using Qiagen miRNeasy kit, were process and applied to Agilent human miRNA arrays. Array data was normalized and analyzed using Agilent GeneSpring program.
Project description:BACKGROUND:Expression of p16 is increased in a number of malignancies, including prostate cancer (PCa). Recent studies in a European cohort showed that expression of p16 is correlated with expression of the TMPRSS2/ERG (T/E) fusion protein. The T/E fusion is significantly less common in PCas in African American (AA) men. Thus, it would be predicted that p16 expression should be less common in PCas in AA men. We, therefore, sought to compare the expression of p16 in benign prostate and PCas from AA and European American (EA) men. METHODS:Immunohistochemistry for p16 and ERG was performed on tissue microarrays constructed from radical prostatectomies performed on AA and EA veterans. Staining was scored and the scores compared with demographic, clinical and pathological parameters. Percent of West African ancestry in the AA cohort was assessed using ancestry informative markers. RESULTS:Contrary to our predictions, p16 expression was similar in the cancers in the AA and EA cohorts. Consistent with prior reports, expression of p16 was quite low in benign prostate tissues from EA patients but surprisingly was significantly higher in benign tissues from AA patients. Expression of p16 was significantly associated with a family history of PCa in AA men. In addition, p16 was associated with ERG expression in AA PCa. CONCLUSIONS:While overall expression of p16 is similar in PCas from the two racial groups, the expression of p16 in benign tissues from a subset of AA men and the stronger correlation with ERG expression implies that there are different mechanisms for p16 overexpression in PCas from the two racial groups.
Project description:Prostate cancer (PCa) tends to be more aggressive and lethal in African Americans (AA) compared to European Americans (EA). To further understand the biological factors accounting for the PCa disparities observed in AA and EA patients, we performed gene profiling analysis using Affymetrix human exon 1.0 ST arrays to identify the differentially expressed genes in AA and EA patients. 35 prostate biopsy specimens (tumor and adjacent normal tissues) were collected from 20 African American and 15 European American prostate cancer patients. RNA samples, purified from the collected biopy specimens, were process and applied to Affymetrix human exon ST 1.0 arrays. Array data was normalized, batch corrected and analyzed (1-way ANOVA) using Partek Genomics Suite program.