Transcriptome analyses of benign and malignant prostate epithelial cells in formalin-fixed paraffin-embedded whole-mounted radical prostatectomy specimens

Abstract

Formalin-fixed paraffin-embedded (FFPE) prostate specimens are rich sources of molecular pathological information. However, FFPE-based microarray analysis of tissue samples may be hampered by the degradation and chemical alteration of RNA molecules due to the preservation procedure. In this report, we employed a probe analyses of Affymetrix oligonucleotide arrays at individual probe level to compensate for the potential loss of gene identifications associated with compromised mRNA quality in FFPE preparations. Furthermore, to increase the sample quality, we utilized laser capture microdissection of prostate tumor and benign epithelial cells. Remarkably, combination of these approaches recapitulated the common prostate cancer-associated gene expression alteration. Identification of prostate cancer associated-gene expression alterations such as AMACR, Kallikrein gene family and genes associated with androgen signaling such as PDEF and STEAP were consistent with previous findings reported in prostate cancer. These data suggest that combination of laser capture dissection with computational enhancement of microarray data may be useful for the assessment of gene expression changes in FFPE prostate cancer specimens.