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Gene-expression Profiles (gene-expression + profile)

Distribution by Scientific Domains

Medical Sciences	62%

Selected Abstracts

Sympathectomy suppresses tumor growth and alters gene-expression profiles in rat tongue cancer

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 4 2009
Bina Raju
Sympathetic nerves are known to affect carcinogenesis. Recently we found that sympathetic denervation decreases the size of rat tongue tumors. To identify genes involved in rat tongue carcinogenesis and to study the effect of sympathetic nerves on these genes, we compared gene-expression profiles in normal rat tongue (control) and in tumor-induced tongues with (SCGx) and without (Sham) bilateral sympathectomy. Significance analysis of microarrays revealed 280 genes (168 up-regulated, 112 down-regulated) that showed at least a twofold differential expression between Sham and SCGx tumors (false discovery rate < 5%). These included genes associated with cell adhesion, signaling, structure, proliferation, metabolism, angiogenesis, development, and immunity. Hierarchical clustering demonstrated that controls and sympathectomized tumors grouped together, while Sham tumors grouped separately. We identified 34 genes, known to be involved in carcinogenesis, that were not differentially expressed between sympathectomized tumors and control tongues, but which showed a significant change in expression in Sham tumors. Microarray results of 12 of these genes were confirmed by quantitative reverse transcription,polymerase chain reaction. In conclusion, sympathectomy significantly altered the gene-expression profile and inhibited tumor growth. The expression of several cancer genes were increased more than threefold in Sham tumors, but unaltered in the sympathectomized tumors when compared with controls, indicating that these genes may be of significance in rat tongue carcinogenesis. [source]

Neuroprotective effects of Brazilian green propolis and its main constituents against oxygen-glucose deprivation Stress, with a gene-expression analysis

PHYTOTHERAPY RESEARCH, Issue 10 2009
Yoshimi Nakajima
Abstract Our purpose was to investigate the neuroprotective effects (and the underlying mechanism) exerted by water extract of Brazilian green propolis (WEP) and its main constituents against the neuronal damage induced by oxygen-glucose deprivation (OGD)/reoxygenation in retinal ganglion cells (RGC-5, a rat ganglion cell-line transformed using E1A virus). Cell damage was induced by OGD 4 h plus reoxygenation 18 h exposure. In RGC-5, and also in PC12 (rat pheochromocytoma, neuronal cells), WEP and some of its main constituents attenuated the cell damage. At the end of the period of OGD/reoxygenation, RNA was extracted and DNA microarray analysis was performed to examine the gene-expression profile in RGC-5. Expression of casein kinase 2 (CK2) was down-regulated and that of Bcl-2-related ovarian killer protein (Bok) was up-regulated following OGD stress, results that were confirmed by quantitative reverse transcriptase-PCR (qRT-PCR). These effects were normalized by WEP. Our findings indicate that WEP has neuroprotective effects against OGD/reoxygenation-induced cell damage and that certain constituents of WEP (caffeoylquinic acid derivatives, artepillin C, and p -coumaric acid) may be partly responsible for its neuroprotective effects. Furthermore, the protective mechanism may involve normalization of the expressions of antioxidant- and apoptosis-related genes (such as CK2 and Bok, respectively). Copyright © 2009 John Wiley & Sons, Ltd. [source]

Differential Expression and Network Inferences through Functional Data Modeling

BIOMETRICS, Issue 3 2009
Donatello Telesca
Summary Time course microarray data consist of mRNA expression from a common set of genes collected at different time points. Such data are thought to reflect underlying biological processes developing over time. In this article, we propose a model that allows us to examine differential expression and gene network relationships using time course microarray data. We model each gene-expression profile as a random functional transformation of the scale, amplitude, and phase of a common curve. Inferences about the gene-specific amplitude parameters allow us to examine differential gene expression. Inferences about measures of functional similarity based on estimated time-transformation functions allow us to examine gene networks while accounting for features of the gene-expression profiles. We discuss applications to simulated data as well as to microarray data on prostate cancer progression. [source]

Sympathectomy suppresses tumor growth and alters gene-expression profiles in rat tongue cancer

Genome-wide analysis of gene expression in human intrahepatic cholangiocarcinoma,

HEPATOLOGY, Issue 6 2005
Kazutaka Obama
Intrahepatic cholangiocarcinoma is a neoplasm arising in the liver, and its incidence is increasing in Japan as well as in Western countries. Prognosis of patients with this type of tumor remains unsatisfactory because no effective chemotherapeutic drugs are available, we have no sensitive tumor markers to detect this tumor in its early stage, and it is difficult to identify a high-risk group for the disease. To clarify the molecular mechanism of tumorigenesis and identify molecular targets for diagnosis and treatment, we analyzed global gene-expression profiles of 25 intrahepatic cholangiocarcinomas using tumor cell populations purified by laser microbeam microdissection and a cDNA microarray containing 27,648 genes. We identified 52 genes that were commonly upregulated and 421 that were downregulated in intrahepatic cholangiocarcinomas compared with noncancerous biliary epithelial cells. From the 52 upregulated genes, we selected P-cadherin and survivin for further investigation and corroborated enhanced expression of their products in cancer tissues by immunohistochemical staining. Furthermore, comparison between tumors with lymph node metastasis and those without metastasis identified 30 genes that were associated with lymph node involvement. In conclusion, these data should be helpful for a better understanding of the tumorigenesis of intrahepatic cholangiocarcinoma and should contribute to the development of diagnostic and therapeutic strategies for this type of tumor. Supplementary material for this article can be found on the HEPATOLOGY website (http://www.interscience.wiley.com/jpages/0270-9139/suppmat/index.html). (HEPATOLOGY 2005.) [source]

Genome-wide analysis of gene expression in adult Anopheles gambiae

INSECT MOLECULAR BIOLOGY, Issue 1 2006
O. Marinotti
Abstract With their genome sequenced, Anopheles gambiae mosquitoes now serve as a powerful tool for basic research in comparative, evolutionary and developmental biology. The knowledge generated by these studies is expected to reveal molecular targets for novel vector control and pathogen transmission blocking strategies. Comparisons of gene-expression profiles between adult male and nonblood-fed female Anopheles gambiae mosquitoes revealed that roughly 22% of the genes showed sex-dependent regulation. Blood-fed females switch the majority of their metabolism to blood digestion and egg formation within 3 h after the meal is ingested, in detriment to other activities such as flight and response to environment stimuli. Changes in gene expression are most evident during the first, second and third days after a blood meal, when as many as 50% of all genes showed significant variation in transcript accumulation. After laying the first cluster of eggs (between 72 and 96 h after the blood meal), mosquitoes return to a nongonotrophic stage, similar but not identical to that of 3-day-old nonblood-fed females. Ageing and/or the nutritional state of mosquitoes at 15 days after a blood meal is reflected by the down-regulation of ,5% of all genes. A full description of the large number of genes regulated at each analysed time point and each biochemical pathway or biological processes in which they are involved is not possible within the scope of this contribution. Therefore, we present descriptions of groups of genes displaying major differences in transcript accumulation during the adult mosquito life. However, a publicly available searchable database (http://www.angagepuci.bio.uci.edu/) has been made available so that detailed analyses of specific groups of genes based on their descriptions, functions or levels of gene expression variation can be performed by interested investigators according to their needs. [source]