Prostate cancer is a biologically heterogeneous disease with considerable variation in clinical aggressiveness. The behavior of prostate cancer can be considered a direct or indirect result of aberrant alterations of gene expression in prostate epithelial cells. Identification of the patterns of gene-expression alterations that are related to the aggressiveness of prostate cancers will greatly assist the development of tools for early detection of prostate cancers with poor clinical outcome and identification of targets for future therapeutic intervention. To detect the patterns of gene-expression alterations of prostate cancers, we performed a comprehensive gene-expression analysis on 30 prostate tissues of various levels of invasiveness (ranging from those confined to the organ to distant metastases) and Gleason grades (combined scores 4-9), using the Affymetrix chip set Hu35k (A-D) and U95a. Following three sequential selection screens, we identified 84 largely novel genes and expressed sequence tag (EST) sequences whose expression levels were altered significantly in prostate cancer samples compared with control normal tissues. In addition, the expression levels of a group of 12 genes and EST sequences was found to be altered significantly in aggressive type of prostate cancers but not in organ-confined prostate cancers. Cluster analysis using the 84-gene list showed that the highly aggressive prostate cancers contained gene-expression patterns that were distinct from organ-confined prostate cancers.

UV exposure and serum levels of vitamin D have been linked in several studies with prostate cancer risk. At the cellular level, the principal action of vitamin D is mediated though vitamin D receptors (VDR). Since prostate cancer is a disease strongly associated with age, we examined the presence of VDR in normal prostate from donors of various ages to determine if the VDR expression pattern changed with age. We also compared the VDR expression in the peripheral and central zones of the prostate to determine if the expression pattern varied by location. Immunohistochemical studies were performed on paraffin-embedded tissue from cases selected by the following age decades; 10-19, 20-29, 30-39, 40-49, 50-59, and 60-69. Both the central and peripheral zones were examined for VDR expression. The intensity of VDR expression in prostate was compared with expression in different types of human tissues. Mean VDR expression was lowest in the 10-19 years of age group. The intensity of the nuclear VDR was higher though the fifth decade, and then declined in cases of ages 60-70. When multiple sections of the same donor prostate were compared, VDR expression was greater in the peripheral zone compared to the central zone.

Cadherins are a family of transmembrane proteins that play a crucial role in cell differentiation, cell migration, and intercellular adhesion. Cadherins are associated with catenins through their highly conserved cytoplasmic domain. Down-regulation of E-cadherin protein has been shown in various human cancers. This study examined the expression of cadherins and associated catenins at the mRNA level. Paired tumor and nonneoplastic primary prostate cultures were obtained from surgical specimens. Quantitative multiplex fluorescence reverse transcriptase-polymerase chain reaction (QMF RT-PCR) and quantitative analysis were performed and correlated with immunostain results. Six of seven cases of neoplastic cultures showed moderately-to-markedly decreased levels of E-cadherin and P-cadherin mRNA. Similar losses of alpha-catenin and beta-catenin mRNA were also observed. The results of QMF RT-PCR showed good correlation with the results of immunohistochemical studies based on corresponding formalin-fixed sections. In conclusion, this paper presents a coordinated down-regulation in the expression of E-cadherin and associated catenins at the mRNA and protein level in most of the cases studied. This down-regulation may play an important role in the pathogenesis of prostate cancer.

The standard practice of tissue fixation in 10% formalin followed by embedding in paraffin wax preserves cellular morphology at the expense of availability and quality of DNA and RNA. The negative effect on cellular constituents results from a combination of extensive cross-linking and strand scission of DNA, RNA, and proteins induced by formaldehyde as well as RNA loss secondary to ubiquitous RNase activity and negative effects of high temperature exposure during paraffin melting, microscopic section collection, and tissue adherence to glass slides. An effective strategy to correlate cellular phenotype with molecular genotype involves microdissection of tissue sections based on specific histopathological features followed by genotyping of minute representative samples for specific underlying molecular alterations. Currently, this approach is limited to short-length polymerase chain reaction amplification (<250 bp) of DNA, due to the negative effects of standard tissue fixation and processing. To overcome this obstacle and permit both cellular morphology and nucleic acid content to be preserved to the fullest extent, we instituted a system of cold-temperature plastic resin embedding based on the use of the water-miscible methyl methacrylate polymer known as Immunobed (Polysciences, Warminster, PA). The system is simple, easy to adapt to clinical practice, and cost-effective. Immunobed tissue sections demonstrate a cellular appearance equivalent or even superior to that of standard tissue sections. Moreover, thin sectioning (0.5-1.0 microm thickness) renders ultrastructural evaluation feasible on plastic-embedded blocks. Tissue microdissection is readily performed, yielding high levels of long DNA and RNA for genomic and transcription-based correlative molecular analysis. We recommend the use of Immunobed or similar products for use in molecular anatomical pathology.

The Strongin-Hinsie Peck whole-mouth salivation measure (Peck, 1959)is typically collected for a 2-min duration. This study compared saliva collected for 120 sec with saliva collected for shorter durations (30 and 60sec) over repeated presentation of gustatory cues. Results showed reliable increases in salivation from a water stimulus baseline to the first presentation of lemon juice as a function of measurement duration. Repeated measures analysis of variance showed overall decreases in salivation across each measurement duration, with a greater rate of habituation for the 120-secinterval than for the 30-and 6o-sec intervals. These data suggest that shorter measurement intervals can be used to measure salivation in acute and repeated measurement paradigms, but the change in response to repeated stimulus presentations is more pronounced for the longer measurement duration.Salivation is an important physiological measure in the study of intake and ingestive behaviors. Salivation has been shown to change in response to olfactory and gustatory cues as a function of factors that initiate intake, such as the degree of hunger and deprivation (Wardle,