Prostate tumors are complex entities composed of malignant cells mixed and interacting with nonmalignant cells. However, molecular analyses by standard gene expression profiling are limited because spatial information and nontumor cell types are lost in sample preparation. We scored 88 prostate specimens for relative content of tumor, benign hyperplastic epithelium, stroma, and dilated cystic glands. The proportions of these cell types were then linked in silico to gene expression levels determined by microarray analysis, revealing unique cell-specific profiles. Gene expression differences for malignant and nonmalignant epithelial cells (tumor versus benign hyperplastic epithelium) could be identified without being confounded by contributions from stroma that dominate many samples or sacrificing possible paracrine influences. Cellspecific expression of selected genes was validated by immunohistochemistry and quantitative PCR. The results provide patterns of gene expression for these three lineages with relevance to pathogenetic, diagnostic, and therapeutic considerations.microarray ͉ expression profiles ͉ linear regression ͉ biomarkers ͉ paracine

Behavioral models indicate that persistent small afferent input, as generated by tissue injury, results in a hyperalgesia at the site of injury and a tactile allodynia in areas adjacent to the injury site. Local tissue injury and inflammation yields well-defined escape behaviors in animals and pain reports in humans. Examination of the histochemistry and electrophysiology of spinal systems has revealed considerable detail regarding the elements of systems that are activated by these stimuli. Nevertheless, the functional contribution of different spinal systems in pain processing ultimately must be defined in terms of the systems in which such end points can be measured, e.g., the behavior of the intact organism. We will consider below how certain spinal systems contribute to the observed behavioral states. Behavioral Effects of Cutaneous Stimuli After InjuryAn acute, unconditioned, thermal, or mechanical stimulus sufficient to activate polymodel nociceptive afferents (C fibers) depolarizes populations of dorsal horn wide dynamic range (WDR) neurons that project supraspinally. This output in turn evokes a supraspinally organized escape behavior. The hot plate test (thermal stimulus to the paw) or the local injection of an irritant such as formalin or capsaicin where the unconditioned stimulus evokes a somatotopically directed behavior (e.g., withdrawal or licking) are behavioral paradigms believed to reflect this underlying mechanism (1). The more intense the stimulus, the more robust will be the afferent volley and the more vigorous or shorter latencied is the escape behavior (2).An acute stimulus of intensity and duration that leads to tissue injury also produces an acute discharge. In addition, the injury leads to the local release of active factors that evoke and sustain persistent activity in the sensory afferents innervating the injured or inflamed tissue (3). Thus, in contrast to the acute response, injury leads to persistent activity in populations of small afferents and also may activate afferent populations that are excited only in the presence of local factors generated by the injury (e.g., silent ''nociceptors'') (4). Electrophysiological studies have shown that the persistent activation of spinal WDR neurons by small, but not large, afferents, will lead: (i) a progressive enhancement of the WDR response to each subsequent input, and (ii) an increase in the dimensions of the peripheral receptive field to which the spinal neuron will respond (5). This electrophysiological observation parallels behavioral changes in which the animal displays an enhanced response to a given stimulus or a reduction in the intensity of the stimulus required to evoke an escape response. Thus, the injection of an irritant (formalin) into one hind paw evokes a high frequency barrage during the first 10-20 min followed by a modest ongoing discharge over the next hour (6). Coincident with the initial afferent barrage, WDR neurons display an initial burst of activity followed by a period of quiescence and then a progress...

Normal mammalian development requires a diploid combination of both haploid parental genomes. Uniparental disomy for certain segments of specific chromosomes results in aberrant development or prenatal lethality, indicating that the parental genomes have undergone modifications during gametogenesis. These modifications result in parent-of-origin specific expression for some genes, a phenomenon called genomic imprinting. Recent work with DNA methyltransferase deficient mice showed that differential methylation is the probable basis of the imprinted character of several genes. Screening for endogenous imprinted loci using restriction landmark genomic scanning with methylation sensitive enzymes (RLGS-M) identified eight imprinted RLGS (Irigs) candidate loci. Molecular analysis of the genomic region of one of the loci (Irigs2) resulted in the discovery of the paternally imprinted U2afbp-rs gene within a previously identified imprinted region on mouse chromosome 11 (refs 5, 7). This paper describes the characterisation of a novel imprinted RLGS-M locus, Irigs3, on mouse chromosome 9 (ref. 6). Within this locus we identified the Grf1 (also called Cdc25Mm) gene, which is homologous to the RAS-specific guanine nucleotide exchange factor gene, CDC25, in Saccharomyces cerevisiae. Grf1 is located about 30 kb downstream of the methylation imprinted site, identified by RLGS-M, and shows paternal allele specific expression in mouse brain, stomach and heart. Our results indicate that imprinting may have a role in regulating mitogenic signal transduction pathways during growth and development.

Dinucleotide (CA)n repeat sequences are highly abundant and interspersed in eukaryotic genomes. Individual sites or loci can be identified by PCR-based assays using unique sequence oligonucleotides that flank specific CA-repeats. The number of CA-repeats at a given locus is variable making these markers highly informative for genetic analysis in humans (1) and other species (2). Unique sequences flanking specific (CA)n loci are usually identified by analyzing genomic libraries containing small size inserts, suitable for sequencing, generated by restriction enzymes. However the construction and screening of these type