Tammy Sadler

Androgen-regulated genes (ARGs) are essential for the development of the prostate. Ironically, ARGs are also responsible for the pathogenesis of prostate cancer. We used oligonucleotide array technology to study the expression profiles of ARGs in LNCaP prostate cancer cells and identified 692 dihydrotestosterone-regulated genes. Representative clusters containing genes with similar expression patterns to prostate-specific antigen and other known ARGs are discussed. Based on functional information, we categorized several candidate targets for prostate cancer therapy and diagnosis. Although many of these candidate targets are known to play an important role in cancer development, several are novel genes to the field of prostate cancer. A cross-comparison study of our results with those that have been previously published from three other array experiments using a similar LNCaP model validated 13 of these candidate targets as androgen-regulated. FKBP51 (FK506-binding immunophilin 51) was found in the same cluster as prostate-specific antigen and its protein expression was increased in LNCaP cells treated with either dihydrotestosterone or synthetic androgen R1881. Results from mining the Gene Logic BioExpress database showed that FKBP51 expression is significantly higher in the prostate cancer group than in the normal and normal adjacent group. Additionally, the androgen-independent prostate tumor xenograft, CWR22R, had higher FKBP51 protein levels than that of the androgen-dependent prostate tumor xenograft, CWR22. A tissue microarray study further revealed that FKBP51 protein expression was higher in prostate cancer specimens than in benign prostate tumor samples. These results suggest the potential value of FKBP51 as a novel diagnostic marker or target for prostate cancer therapy.

BACKGROUND: Fibrosis of the intestine is a common and poorly understood complication of Crohn's disease (CD) characterized by excessive deposition of extracellular matrix and accompanied by narrowing and obstruction of the gut lumen. Defining the molecular characteristics of this fibrotic disorder is a vital step in the development of specific prediction, prevention, and treatment strategies. Previous epigenetic studies indicate that alterations in DNA methylation could explain the mechanism by which mesenchymal cells adopt the requisite pro-fibrotic phenotype that promotes fibrosis progression. However, to date, genome-wide analysis of the DNA methylome of any type of human fibrosis is lacking. We employed an unbiased approach using deep sequencing to define the DNA methylome and transcriptome of purified fibrotic human intestinal fibroblasts (HIF) from the colons of patients with fibrostenotic CD. RESULTS: When compared with normal fibroblasts, we found that the majority of differential DNA methylation was within introns and intergenic regions and not associated with CpG islands. Only a low percentage occurred in the promoters and exons of genes. Integration of the DNA methylome and transcriptome identified regions in three genes that inversely correlated with gene expression: wingless-type mouse mammary tumor virus integration site family, member 2B (WNT2B) and two eicosanoid synthesis pathway enzymes (prostacyclin synthase and prostaglandin D2 synthase). These findings were independently validated by RT-PCR and bisulfite sequencing. Network analysis of the data also identified candidate molecular interactions relevant to fibrosis pathology. CONCLUSIONS: Our definition of a genome-wide fibrosis-specific DNA methylome provides new gene networks and epigenetic states by which to understand mechanisms of pathological gene expression that lead to fibrosis. Our data also provide a basis for development of new fibrosis-specific therapies, as genes dysregulated in fibrotic Crohn's disease, following functional validation, can serve as new therapeutic targets.