Gene expression profiling of prostate tissues and seminal vesicles from PB-Pten-NICD mice. Mus musculus

To investigate the identity of the tissue origin for metastases, we compared gene expression profiles of the prostate tissues and seminal vesicles from PB-Pten-NICD mice and those of 7 lung metastases from different mice. Three respective cell lines established from primary seminal vesicle tumors, primary prostate tumors, and lung metastases in PB-Pten-NICD mice were also included in the microarray analysis. We hypothesized that the gene expression profiles of primary and metastatic tumors should resemble those of their tissue origins. We identified genes differentially expressed between the seminal vesicle and prostate tumors. The expression profiles of the two cell lines established from primary tumors resembled those of their respective tissue origins, which supports our hypothesis. The expression profile of the metastatic cell line resembled those of the prostate tumor tissues, indicating the prostate as its tissue of origin. The expression profiles of 2 metastatic specimens each resembled those of the seminal vesicle tumors and the prostate tumors, respectively, while the expression profiles of the remaining 3 samples displayed a mixed pattern. This study suggests that metastatic tumors in this model may have originated from either the prostate, or the seminal vesicles, or both. Overall design: Gene expression microarray analyses were performed on prostate tissues and seminal vesicles (SVs) from PB-Pten-NICD mice, on lung metastases from different mice, and on three respective cell lines established from primary seminal vesicle tumors, primary prostate tumors, and lung metastases in PB-Pten-NICD mice.