[900] Comparative Analysis of Gene Expression Sigunatures of 3-D Culture Specific Genes and Epithelial Specific Genes from Clinicaly Localized Human Prostate Normal and Cancer Specimens

T Tsunoda, B Furusato, DR Tyson, S Ravulapalli, A Dobi, S Srivastava, S Naito, IA Sesterhenn, DK Ornstein. University of California, Irvine, Irvine, CA; Armed Forces Institute of Pathology, Washington, DC; Center for Prostate Disease Research, Rockville, MD; Kyushu University, Kyusyu, Japan; Fukuoka University, Fukuoka, Japan

Background: Development of prostate cancer (CaP) is associated with the dysregulation of the normal homeostatic process responsible for maintaining glandular structure. Recently, a method to recapitulate acinar morphogenesis using a benign prostatic epithelial cell line in three-dimensional culture (3-DC) was established. We found that 3-DC specific genes are cooperatively regulated when making acinar morphology. We hypothesized that these genes would be important in maintaining prostatic acini in vivo and dysregulation of these genes may play a role in CaP initiation and development. Therefore, we assessed the expression of these 3-DC specific genes in 80 microarray data sets of matching tumor and benign specimens isolated by laser capture microdissection (LCM).
Design: Human benign prostatic epithelial cell line, RWPE-1 and TA2 were cultured in 2-D with 2% matrigel or 3-DC. Total mRNA was extracted from cells in each culture condition and from LCM specimens. All the samples were amplified by the T7-based linear amplification method. Gene expression analyses were performed by Genesprings and Ingenuity Pathway Analyses using Affymetrix microarrays.
Results: In 3-DC, consistent down regulation of 126 genes and up regulation of 175 genes were observed when compared to 2D matrigel cultures. In silico pathway analyses revealed the suppression of the transforming growth factor beta (TGFbeta) signaling pathway and upregulation of epidermal growth factor receptor (EGFR) and integrin signaling pathways. Analysis of human benign and CaP samples confirmed the importance of these pathways and further identified altered expression of nephronectin, ribonucleotide reductase M2 polypeptide, osteoblast specific factor 2, and E74 like factor 3 specifically in CaP.
Conclusions: Both EGFR and TGFbeta signaling pathways are suggested to be essential pathway for cancer initiation and development. The up-regulated genes, NPNT, RRM2 and OSF2 appear to be associated with the cellular growth through EGFR and integrin pathways by analyses in silico. The ELF3 gene was reduced and associated with dedifferentiation through TGFbeta receptor downregulation.
Category: Genitourinary (including renal tumors)

Wednesday, March 11, 2009 1:00 PM

Poster Session VI # 117, Wednesday Afternoon