Olfactory Receptor Family Research Articles

High-throughput analysis of mammalian olfactory receptors: measurement of receptor activation via luciferase activity.

Odorants create unique and overlapping patterns of olfactory receptor activation, allowing a family of approximately 1,000 murine and 400 human receptors to recognize thousands of odorants. Odorant ligands have been published for fewer than 6% of human receptors(1-11). This lack of data is due in part to difficulties functionally expressing these receptors in heterologous systems. Here, we describe a method for expressing the majority of the olfactory receptor family in Hana3A cells, followed by high-throughput assessment of olfactory receptor activation using a luciferase reporter assay. This assay can be used to (1) screen panels of odorants against panels of olfactory receptors; (2) confirm odorant/receptor interaction via dose response curves; and (3) compare receptor activation levels among receptor variants. In our sample data, 328 olfactory receptors were screened against 26 odorants. Odorant/receptor pairs with varying response scores were selected and tested in dose response. These data indicate that a screen is an effective method to enrich for odorant/receptor pairs that will pass a dose response experiment, i.e. receptors that have a bona fide response to an odorant. Therefore, this high-throughput luciferase assay is an effective method to characterize olfactory receptors-an essential step toward a model of odor coding in the mammalian olfactory system.

Genomic organization and evolution of the trace amine-associated receptor (TAAR) repertoire in Atlantic salmon (Salmo salar).

There is strong evidence that olfaction plays a key role in the homing of salmonids to their natal spawning grounds, particularly in the freshwater phase. However, the physiological and genetic mechanisms behind this biological phenomenon are largely unknown. It has been shown that Pacific salmon respond to dissolved free amino acids from their natal streams. This indicates that amino acids comprise part of the olfcatory cues for imprinting and homing in salmonids. As trace amine-associated receptors (TAARs), a class of olfactory receptors that are close relatives of the G protein-coupled aminergic neurotransmitter receptors, recognize amino acid metabolites, we hypothesize that TAARs play an important role in salmon homing by recognizing olfactory cues. Therefore, to better understand homing in Atlantic salmon, we set out to characterize the TAAR genes in this species. We searched the first assembly of the Atlantic salmon genome for sequences resembling TAARs previously characterized in other teleosts. We identified 27 putatively functional TAAR genes and 25 putative TAAR pseudogenes, which cluster primarily on chromosome 21 (Ssa21). Phylogenetic analysis of TAAR amino acid sequences from 15 vertebrate species revealed the TAAR gene family arose after the divergence of jawed and jawless vertebrates. The TAARs group into three classes with salmon possessing class I and class III TAARs. Within each class, evolution is characterized by species-specific gene expansions, which is in contrast to what is observed in other olfactory receptor families (e.g., OlfCs and oras).

Dynamics of mRNA and polysomal abundance in early 3T3-L1 adipogenesis

BackgroundAdipogenesis is a complex process, in which immature pre-adipocytes change morphology, micro-anatomy and physiology to become mature adipocytes. These store and accumulate fat and release diverse hormones. Massive changes in protein content and protein composition of the transforming cell take place within a short time-frame.In a previous study we analyzed changes in the abundance of free and polysomal, i.e. ribosome bound, RNAs in the first hours of adipogenesis in the murine cell line 3T3-L1. Here we analyze changes of mRNA levels and their potential contribution to the changing protein pool by determination of mRNA levels and ribosome binding to mRNAs in 3T3-L1 cells stimulated for adipogenesis. We grouped mRNA species into categories with respect to up- or down-regulated transcription and translation and analyzed the groups regarding specific functionalities based on Gene Ontology (GO).ResultsA shift towards up-regulation of gene expression in early adipogenesis was detected. Genes up-regulated at the transcriptional (TC:up) and translational (TL:up) level (TC:up/TL:up) are very likely involved in control and logistics of translation. Many of them are known to contain a TOP motif. In the TC:up/TL:unchanged group we detected most of the metal binding proteins and metal transporters. In the TC:unchanged/TL:up group several factors of the olfactory receptor family were identified, while in TC:unchanged/TL:down methylation and repair genes are represented. In the TC:down/TL:up group we detected many signaling factors. The TC:down/TL:unchanged group mainly consists of regulatory factors.ConclusionsWithin the first hours of adipogenesis, changes in transcriptional and translational regulation take place. Notably, genes with a specific biological or molecular function tend to cluster in groups according to their transcriptional and translational regulation.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-381) contains supplementary material, which is available to authorized users.

Chemosensory functions for pulmonary neuroendocrine cells.

The mammalian airways are sensitive to inhaled stimuli, and airway diseases are characterized by hypersensitivity to volatile stimuli, such as perfumes, industrial solvents, and others. However, the identity and function of the cells in the airway that can sense volatile chemicals remain uncertain, particularly in humans. Here, we show that solitary pulmonary neuroendocrine cells (PNECs), which are morphologically distinct and physiologically undefined, might serve as chemosensory cells in human airways. This conclusion is based on our finding that some human PNECs expressed members of the olfactory receptor (OR) family in vivo and in primary cell culture, and are anatomically positioned in the airway epithelium to respond to inhaled volatile chemicals. Furthermore, apical exposure of primary-culture human airway epithelial cells to volatile chemicals decreased levels of serotonin in PNECs, and the led to the release of the neuropeptide calcitonin gene-related peptide (CGRP) to the basal medium. These data suggest that volatile stimulation of PNECs can lead to the secretion of factors that are capable of stimulating the corresponding receptors in the lung epithelium. We also found that the distribution of serotonin and neuropeptide receptors may change in chronic obstructive pulmonary disease, suggesting that increased PNEC-dependent chemoresponsiveness might contribute to the altered sensitivity to volatile stimuli in this disease. Together, these data indicate that human airway epithelia harbor specialized cells that respond to volatile chemical stimuli, and may help to explain clinical observations of odorant-induced airway reactions.

Critical Association Study of Olfactory Receptor Gene Polymorphism in Diabetic Complications

Type I diabetes (TID) is an autoimmune disease (AD) known to trigger retinopathy, neuropathy and nephropathy. Recent findings suggest that numerous pathways are activated during the course of T1D and that these pathways individually or collectively influence progression to Diabetic Nephropathy (DN). A single nucleotide polymorphism (SNP) in the promoter region of the Olfactory Receptor family 14 (OR14) gene, rs9257691, has been shown to be significantly associated with T1D in general. Recent investigations have emphasized on the significance of OR in diabetic complications. In this pilot study, we sought to confirm these findings by investigating the OR14 gene in a group of patients with and without diabetic complications. A hundred patients with (n=75) and without (n=25) different diabetic complications (i.e. Retinopathy (DR), Neuropathy (DNu) and DN) were recruited. Patients with long term ≥ 20 years history of diabetes with no complications were considered as the control group. Case and control subjects were genotyped for OR14 gene adjacent to the Human Leukocyte Antigen (HLA)-F region. The current results showed that the OR14-CC genotype is more significant in patients with DN, p=0.004, in comparison to groups with other complications. No other statistically significant difference was found among male and female groups. In addition, there was no difference in allelic frequencies of cases compared to control subjects. This critical analysis indicates that patients with T1D who have the OR14-CC genotype are significantly susceptible to progressive DN. Screening and identifying diabetic patients at risk for future nephropathy would permit better clinical management. However, a large scale association study is recommended to confirm the above findings.

Dysregulation of brain olfactory and taste receptors in AD, PSP and CJD, and AD-related model

Recently, we have shown the expression of novel chemoreceptors corresponding to the olfactory receptor (OR) and taste receptor (TASR) families in the human brain. We have also shown dysregulation of ORs and TASRs in the cerebral cortex in Parkinson’s disease. The present study demonstrates the presence of OR mRNA and mRNA of obligated downstream components of OR signaling adenylyl cyclase 3 (ADYLC3) and olfactory G protein (Gnal) in the cerebral cortex of the mouse. Dysregulation of selected ORs and TASRs has been found in the entorhinal cortex and frontal cortex in Alzheimer’s disease (AD) in a gradient compatible with Braak and Braak staging; frontal cortex in terminal stages of Progressive Supranuclear Palsy; and frontal cortex and cerebellum in Creutzfeldt–Jakob disease subtypes methionine/methionine at codón 129 of PRNP (MM1) and valine/valine at codón 129 of PRNP (VV2). Altered OR, ADYLC3 and Gnal mRNA expression with disease progression has also been found in APP/PS1 transgenic mice, used as a model of AD. The function of these orphan receptors is not known, but probably related to cell signaling pathways responding to unidentified ligands.Variability in the drift, either down- or up-regulation, of dysregulated genes, suggests that central ORs and TASRs are vulnerable to variegated neurodegenerative diseases with cortical involvement, and that altered expression of ORs and TASRs is not a mere reflection of neuronal loss but rather a modulated pathological response.

Ancestral amphibian v2r s are expressed in the main olfactory epithelium

Mammalian olfactory receptor families are segregated into different olfactory organs, with type 2 vomeronasal receptor (v2r) genes expressed in a basal layer of the vomeronasal epithelium. In contrast, teleost fish v2r genes are intermingled with all other olfactory receptor genes in a single sensory surface. We report here that, strikingly different from both lineages, the v2r gene family of the amphibian Xenopus laevis is expressed in the main olfactory as well as the vomeronasal epithelium. Interestingly, late diverging v2r genes are expressed exclusively in the vomeronasal epithelium, whereas "ancestral" v2r genes, including the single member of v2r family C, are restricted to the main olfactory epithelium. Moreover, within the main olfactory epithelium, v2r genes are expressed in a basal zone, partially overlapping, but clearly distinct from an apical zone of olfactory marker protein and odorant receptor-expressing cells. These zones are also apparent in the spatial distribution of odor responses, enabling a tentative assignment of odor responses to olfactory receptor gene families. Responses to alcohols, aldehydes, and ketones show an apical localization, consistent with being mediated by odorant receptors, whereas amino acid responses overlap extensively with the basal v2r-expressing zone. The unique bimodal v2r expression pattern in main and accessory olfactory system of amphibians presents an excellent opportunity to study the transition of v2r gene expression during evolution of higher vertebrates.

Olfactory receptors and the mechanism of odor perception

The olfactory system plays one of the key roles in the lives of humans and animals. It can detect thousands of different odor molecules through a large family of olfactory receptors (ORs), of a diverse protein sequence, which are located in olfactory sensory neurons (OSNs) in the olfactory epithelium in the nose of humans, and in the vomeronasal organ in animals. The OR family is comprised of 172 subfamilies, whose members have related protein sequences and are encoded by a single chromosomal locus. The human receptor gene family includes 339 intact receptor genes and 297 receptor pseudogenes, unevenly distributed among 51 different loci on 21 human chromosomes. Different parts of the genome may be involved in the detection of different types of structural odorants. Odor detection is mediated by odorant receptors. Signals generated in OSNs in response to odorants are transmitted to the olfactory bulb (OB) of the brain, i.e., the first relay station in the control of the olfactory system in mammals. Then, signals are transmitted to the olfactory brain cortex, which has a cortical structure with distinct layers and numerous glomerular modules, and forms a map of olfactory axon terminals. The axonal projection of OSNs is precisely organized with a few topographically fixed glomeruli. The purpose of this paper is to present the recent literature in the field of the undertaken subject. The review of articles is devoted to olfactory receptors and the mechanism of odor perception. In the first part, this review summarizes the mammalian protein ORs that are encoded by genes, as well as the location and structure of these receptors. Extensive studies reveal that mammals can have up to 1000 different OR genes, which constitute approximately 1% of the genomic complement of genes. The analysis of the entire receptor family has shown that it is comprised of 172 subfamilies, whose members are 60% identical in protein amino acid sequence and can recognize odorants with related structures. The second part of this review presents the opinions of many authors concerning the olfactory perception that initiates in the olfactory epithelium. Odor signals are further transmitted to the OB, i.e., the first relay station of the central olfactory system in the mammalian brain. Then such signals ultimately reach higher cortical areas involved in the conscious perception of odor. At the review's conclusion some diseases associated with smell disorders are discussed. The olfactory cortex still remains an unexplored and unexplained area in terms of the processing of odorant information. This subject requires further study.

Identification of New Agonists and Antagonists of the Insect Odorant Receptor Co-Receptor Subunit

BackgroundInsects detect attractive and aversive chemicals using several families of chemosensory receptors, including the OR family of olfactory receptors, making these receptors appealing targets for the control of insects. Insect ORs are odorant-gated ion channels, comprised of at least one common subunit (the odorant receptor co-receptor subunit, Orco) and at least one variable odorant specificity subunit. Each of the many ORs of an insect species is activated or inhibited by an unique set of odorants that interact with the variable odorant specificity subunits, making the development of OR directed insect control agents complex and laborious. However, several N-,2-substituted triazolothioacetamide compounds (VUAA1, VU0450667 and VU0183254) were recently shown to act directly on the highly conserved Orco subunit, suggesting that broadly active compounds can be developed. We have explored the chemical space around the VUAA1 structure in order to identify new Orco ligands.Principal FindingsWe screened ORs from several insect species, using heterologous expression in Xenopus oocytes and an electrophysiological assay, with a panel of 22 compounds structurally related to VUAA1. By varying the nitrogen position in the pyridine ring and altering the moieties decorating the phenyl ring, we identified two new agonists and a series of competitive antagonists. Screening smaller compounds, similar to portions of the VUAA1 structure, also yielded competitive antagonists. Importantly, we show that Orco antagonists inhibit odorant activation of ORs from several insect species. Detailed examination of one antagonist demonstrated inhibition to be through a non-competitive mechanism.ConclusionsA similar pattern of agonist and antagonist sensitivity displayed by Orco subunits from different species suggests a highly conserved binding site structure. The susceptibility to inhibition of odorant activation by Orco antagonism is conserved across disparate insect species, suggesing the ligand binding site on Orco as a promising target for the development of novel, broadly active insect repellants.

A Quantitative Model for Human Olfactory Receptors

AbstractA wide variety of chemicals having distinct odors are smelled by humans. Odor perception initiates in the nose, where it is detected by a large family of olfactory receptors (ORs). Based on divergence of evolutionary model, a sequence of human ORs database has been proposed by D. Lancet et al (2000, 2006). It is quite impossible to infer whether a given sequence of nucleotides is a human OR or not, without any biological experimental validation. In our perspective, a proper quantitative understanding of these ORs is required to justify or nullify whether a given sequence is a human OR or not. In this paper, all human OR sequences have been quantified, and a set of clusters have been made using the quantitative results based on two different metrics. Using this proposed quantitative model, one can easily make probable justification or deterministic nullification whether a given sequence of nucleotides is a probable human OR homologue or not, without seeking any biological experiment. Of course a further biological experiment is essential to validate the probable human OR homologue.

A Quantitative Model for Human Olfactory Receptors

A wide variety of chemicals having distinct odors are smelled by humans. Odor perception initiates in the nose, where it is detected by a large family of olfactory receptors (ORs). Based on divergence of evolutionary model, a sequence of human ORs database has been proposed by D. Lancet et al (2000, 2006). It is quite impossible to infer whether a given sequence of nucleotides is a human OR or not, without any biological experimental validation. In our perspective, a proper quantitative understanding of these ORs is required to justify or nullify whether a given sequence is a human OR or not. In this paper, all human OR sequences have been quantified, and a set of clusters have been made using the quantitative results based on two different metrics. Using this proposed quantitative model, one can easily make probable justification or deterministic nullification whether a given sequence of nucleotides is a probable human OR homologue or not, without seeking any biological experiment. Of course a further biological experiment is essential to validate the probable human OR homologue.

A Quantitative Model for Human Olfactory Receptors

AbstractA wide variety of chemicals having distinct odors are smelled by humans. Odor perception initiates in the nose, where it is detected by a large family of olfactory receptors (ORs). Based on divergence of evolutionary model a sequence of human ORs database has been proposed by D. Lancet et al (2000, 2006). It is quite impossible to infer whether a given sequence of nucleotides is a human OR or not, without any biological experimental validation. In our perspective, a proper quantitative understanding of these ORs is required to justify or nullify whether a given sequence is a human OR or not. In this paper, all human OR sequences have been quantified, and a set of clusters have been made using the quantitative results based on two different metrics. Using this proposed quantitative model, one can easily make probable justification or deterministic nullification whether a given sequence of nucleotides is a probable human OR homologue or not, without seeking any biological experiment. Of course a further biological experiment is essential to validate the probable human OR homologue.

The Olfactory Nervous System Of Terrestrial And Aquatic Vertebrates

AbstractAnimals in their natural milieu are surrounded by odors. These odors are rich source of information, and are perceived by sophisticated olfactory systems, that have evolved over time. The sense of smell helps species to localize prey, evade predators, explore food and recognize viable mates. In humans, memoirs, thoughts, emotions, and associations are more readily reached through the sense of smell than through any other channel. This suggests that olfactory processing is imperative and may differ fundamentally from processing in other sensory modalities. The molecular age in olfaction initiated in 1991 with the significant discovery of a large, multigene family of olfactory receptors in rat by Linda Buck and Richard Axel (Buck and Axel, 1991). The first cloned olfactory receptors consisted of a diverse repertoire of G-protein coupled receptors (GPCRs) with seven-trans membrane topology, and they were sparsely expressed in the olfactory epithelium. This Nobel Prize worthy pioneering discovery, together with availability of modern techniques and numerous completely sequenced genomes opened the way to characterize the gene families of olfactory receptors through exhaustive computational data mining in different species genome as well as by in vitro biology. In this review, I will explain about the two main model organism of olfactory perceptions, zebrafish and mouse.

Crypt Neurons Express a Single V1R-Related ora Gene

Both ciliated and microvillous olfactory sensory neuron populations express large families of olfactory receptor genes. However, individual neurons generally express only a single receptor gene according to the "one neuron-one receptor" rule. We report here that crypt neurons, the third type of olfactory neurons in fish species, use an even more restricted mode of expression. We recently identified a novel olfactory receptor family of 6 highly conserved G protein-coupled receptors, the v1r-like ora genes. We show now that a single member of this family, ora4 is expressed in nearly all crypt neurons, whereas the other 5 ora genes are not found in this cell type. Consistent with these findings, ora4 is never coexpressed with any of the remaining 5 ora genes. Furthermore, several lines of evidence indicate the absence of any other olfactory receptor families in crypt neurons. These results suggest that the vast majority of the crypt neuron population may select one and the same olfactory receptor gene, a "one cell type-one receptor" mode of expression. Such an expression pattern is familiar in the visual system, with rhodopsin as the sole light receptor of rod photoreceptor cells, but unexpected in the sense of smell.

Positive Darwinian Selection And The Birth Of An Olfactory Receptor Clade In Teleost Fish

AbstractTrace amine-associated receptors (TAARs) in mammals recently have been shown to function as olfactory receptors. We have delineated the taar gene family in jawless, cartilaginous and bony fish (zero, two, and more than hundred genes, respectively). We conclude that taar genes are evolutionary much younger than the related OR and ORA/V1R olfactory receptor families, which are present already in lamprey, a jawless vertebrate. The two cartilaginous fish genes appear to be ancestral for two taar classes, each with mammalian and bony fish (teleost) representatives. Unexpectedly, a whole new clade, class III, of taar genes originated even later, within the teleost lineage. Taar genes from all three classes are expressed in subsets of zebrafish olfactory receptor neurons, supporting their function as olfactory receptors. Expression of most TAAR genes in 5dpf zebrafish is found restricted to olfactory epithelium (OE). The highly conserved TAAR1 (shark, mammalian and teleost orthologs) is not expressed in the olfactory epithelium and may constitute the sole remnant of a primordial, non-olfactory function of this family. Class III comprises three-fourths of all teleost taar genes, and is characterized by the complete loss of the aminergic ligand-binding motif, stringently conserved in the other two classes. Two independent intron gains in class III taar genes represent extraordinary evolutionary dynamics considering the virtual absence of intron gains during vertebrate evolution. The dN/dS analysis suggests both minimal global negative selection and an unparalleled degree of local positive selection as another hallmark of class III genes. The accelerated evolution of class III teleost taar genes conceivably might mark the birth of a new olfactory receptor gene family.

Complementary Function and Integrated Wiring of the Evolutionarily DistinctDrosophilaOlfactory Subsystems

To sense myriad environmental odors, animals have evolved multiple, large families of divergent olfactory receptors. How and why distinct receptor repertoires and their associated circuits are functionally and anatomically integrated is essentially unknown. We have addressed these questions through comprehensive comparative analysis of the Drosophila olfactory subsystems that express the ionotropic receptors (IRs) and odorant receptors (ORs). We identify ligands for most IR neuron classes, revealing their specificity for select amines and acids, which complements the broader tuning of ORs for esters and alcohols. IR and OR sensory neurons exhibit glomerular convergence in segregated, although interconnected, zones of the primary olfactory center, but these circuits are extensively interdigitated in higher brain regions. Consistently, behavioral responses to odors arise from an interplay between IR- and OR-dependent pathways. We integrate knowledge on the different phylogenetic and developmental properties of these receptors and circuits to propose models for the functional contributions and evolution of these distinct olfactory subsystems.

Shared and Unique G Alpha Proteins in the Zebrafish Versus Mammalian Senses of Taste and Smell

Chemosensory systems in vertebrates employ G protein-coupled receptors as sensors. In mammals, several families of olfactory and gustatory receptors as well as specific G alpha proteins coupling to them have been identified, for example, gustducin for taste. Orthologous receptor families have been characterized in fish, but the corresponding G alpha genes have not been well investigated so far. We have performed a comprehensive search of several lower vertebrate genomes to establish the G alpha protein family in these taxa and to identify those genes that may be involved in chemosensory signal transduction in fish. We report that gustducin is absent from the genomes of all teleost and amphibian species analyzed, presumably due to independent gene losses in these lineages. However, 2 other G alpha genes, Gi1b and G14a, are expressed in zebrafish taste buds and 4 G proteins, Go1, Go2, Gi1b, and Golf2, were detected in the olfactory epithelium. Golf2, Gi1b, and G14a are expressed already shortly after hatching, consistent with the physiological and behavioral responses of larvae to odorants and tastants. Our results show general similarity to the mammalian situation but also clear-cut differences and as such are essential for using the zebrafish model system to study chemosensory perception.

Acid sensing by the Drosophila olfactory system

The odour of acids has a distinct quality that is perceived as sharp, pungent and often irritating. How acidity is sensed and translated into an appropriate behavioural response is poorly understood. Here we describe a functionally segregated population of olfactory sensory neurons in the fruitfly, Drosophila melanogaster, that are highly selective for acidity. These olfactory sensory neurons express IR64a, a member of the recently identified ionotropic receptor (IR) family of putative olfactory receptors. In vivo calcium imaging showed that IR64a+ neurons projecting to the DC4 glomerulus in the antennal lobe are specifically activated by acids. Flies in which the function of IR64a+ neurons or the IR64a gene is disrupted had defects in acid-evoked physiological and behavioural responses, but their responses to non-acidic odorants remained unaffected. Furthermore, artificial stimulation of IR64a+ neurons elicited avoidance responses. Taken together, these results identify cellular and molecular substrates for acid detection in the Drosophila olfactory system and support a labelled-line mode of acidity coding at the periphery.

Ancient protostome origin of chemosensory ionotropic glutamate receptors and the evolution of insect taste and olfaction.

Ionotropic glutamate receptors (iGluRs) are a highly conserved family of ligand-gated ion channels present in animals, plants, and bacteria, which are best characterized for their roles in synaptic communication in vertebrate nervous systems. A variant subfamily of iGluRs, the Ionotropic Receptors (IRs), was recently identified as a new class of olfactory receptors in the fruit fly, Drosophila melanogaster, hinting at a broader function of this ion channel family in detection of environmental, as well as intercellular, chemical signals. Here, we investigate the origin and evolution of IRs by comprehensive evolutionary genomics and in situ expression analysis. In marked contrast to the insect-specific Odorant Receptor family, we show that IRs are expressed in olfactory organs across Protostomia—a major branch of the animal kingdom that encompasses arthropods, nematodes, and molluscs—indicating that they represent an ancestral protostome chemosensory receptor family. Two subfamilies of IRs are distinguished: conserved “antennal IRs,” which likely define the first olfactory receptor family of insects, and species-specific “divergent IRs,” which are expressed in peripheral and internal gustatory neurons, implicating this family in taste and food assessment. Comparative analysis of drosophilid IRs reveals the selective forces that have shaped the repertoires in flies with distinct chemosensory preferences. Examination of IR gene structure and genomic distribution suggests both non-allelic homologous recombination and retroposition contributed to the expansion of this multigene family. Together, these findings lay a foundation for functional analysis of these receptors in both neurobiological and evolutionary studies. Furthermore, this work identifies novel targets for manipulating chemosensory-driven behaviours of agricultural pests and disease vectors.

Abstract 1153: The development and utilization of a novel DNA microarray platform for biomarker and target identification in advanced prostate cancer

Abstract Prostate cancer is the second leading cause of cancer-related deaths in men; specifically one in six men are diagnosed with prostate cancer in their lifetime. The use of serum prostate-specific antigen (PSA) levels has been lauded as a huge step forward in the diagnosis and treatment of prostate cancer, however since it's implemenatation as a biomarker it has become apparent that the numbers of deaths from prostate cancer has only decreased slightly. Therefore the identification of new biomarkers and treatments for highly invasive/metastatic prostate cancers is of a high priority. We sought to identify new biomarkers and drug targets by performing DNA microarray analysis of prostate tumour samples and normal prostate tissue samples. To further these goals we developed a specific array platform, this array was based upon extensive sequencing of prostate tumour samples and contains approximately 90,000 probesets many of which are specific to prostate cancer. We then utilized this technology to profile a series of fresh high Gleason score primary prostate tumour samples and normal prostate samples. We identified approximately 1,600 transcripts and many associated functionally relevant pathways that were significantly differentially expressed in the prostate tumour samples when compared with the normal prostate samples. Encouragingly we also identified several transcripts which are known to be specifically expressed in prostate cancer including prostate cancer antigen 3 (PCA3), α-methylacyl-coA-racemase AKA 2-methylacyl-CoA 2-epimerase (AMACR) and members of the olfactory receptor family 51, thereby demonstrating that this approach was producing reliable information. Additionally to these transcripts 34% of the 1,600 was annotated as being unique to the prostate cancer disease specific array when compared to available generic microarrays, thereby representing novel potential biomarkers and drug targets. Functional analysis of these unique transcripts annotated many to apoptotic processes, DNA repair and cellular proliferation amongst others. This content may be highly relevant to biomarker and target development for advanced prostate cancer. In conclusion we have developed a novel prostate cancer disease specific array, we have utilized this platform to profiled a series of prostate tumour and normal samples identifying several novel transcripts associated with advanced prostate cancer. Functional annotation of these unique transcripts associated many with processes know to be deregulated in cancer. We believe that this approach demonstrates the utility of this novel platform for the discovery of clinical biomarkers and novel drug targets from tumour tissue. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1153.