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Age and vitamin E-induced changes in gene expression profiles of T cells.

T cells are vulnerable to age-associated changes. Vitamin E has been shown to improve T cell functions in the old. We studied gene expression profiles of T cells to better understand the underlying mechanisms of age and vitamin E-induced changes in T cell function. Young and old C57BL mice were fed diets containing 30 (control) or 500 (supplemented) ppm of vitamin E for 4 wks. Gene expression profiles of T cells were assessed using microarray analysis with/without anti-CD3/anti-CD28 stimulation. Genes associated with cytokines/chemokines, transcriptional regulation, signal transduction, cell cycle, and apoptosis were significantly up-regulated upon stimulation. Higher SOCS3 and lower growth factor independent 1 (Gfi-1) expression in old T cells may contribute to age-associated decline in proliferation. Higher Gadd45 and lower Bcl2 expression may contribute to increased apoptosis in old T cells. Vitamin E supplementation resulted in higher expression of genes involved in cell cycle regulation (Ccnb2, Cdc2, Cdc6) in old T cells. Vitamin E supplementation resulted in higher up-regulation of IL-2 expression in young and old T cells and lower up-regulation of IL-4 expression in old T cells following stimulation. These findings suggest that aging has significant effects on the expression of genes associated with signal transduction, transcriptional regulation, and apoptosis pathways in T cells, and vitamin E has a significant impact on the expression of genes associated with cell cycle and Th1/Th2 balance in old T cells. Further studies are needed to determine whether these changes are due to the effects of aging at a single-cell level or to the shift in the ratio of naïve:memory T cells with age.

Age Factors↗

Abnormal gene expression profiles in human ovaries from polycystic ovary syndrome patients.

Polycystic ovary syndrome (PCOS) represents the most common cause of anovulatory infertility and affects 5-10% of women of reproductive age. The etiology of PCOS is still unknown. The current study is the first to describe consistent differences in gene expression profiles in human ovaries comparing PCOS patients vs. healthy normoovulatory individuals. The microarray analysis of PCOS vs. normal ovaries identifies dysregulated expression of genes encoding components of several biological pathways or systems such as Wnt signaling, extracellular matrix components, and immunological factors. Resulting data may provide novel clues for ovarian dysfunction in PCOS. Intriguingly, the gene expression profiles of ovaries from (long-term) androgen-treated female-to-male transsexuals (TSX) show considerable overlap with PCOS. This observation provides supportive evidence that androgens play a key role in the pathogenesis of PCOS. Presented data may contribute to a better understanding of dysregulated pathways in PCOS, which might ultimately reveal novel leads for therapeutic intervention.

Adult↗

Gene expression profiles in mouse urethral development.

OBJECTIVE: To analyse the gene expression profiles of the mouse genital tubercle (GT) during urethral tube development at embryonic (E) days E14, E15, E16 and E17, as the aetiology of hypospadias, one of the most common congenital anomalies, remains unknown. MATERIALS AND METHODS: During GT development the urethral folds fuse to form an epithelial seam; subsequently, the epithelial seam disappears, resulting in the normal tubular urethra. Abnormalities in urethral seam formation and remodelling might explain hypospadias, and elucidating the molecular developmental mechanisms underlying normal penile development might provide the basis for understanding hypospadias. Total RNA was isolated from the genital tubercle at embryonic days E14, E15, E16, and E17. Together with reference RNA, sample RNA was labelled with Cy-3 and Cy-5 respectively and hybridized to a 16 000-mouse gene array that included the Incyte GEM2.1 and NIA 7k sets. Candidate genes were analysed by immunohistochemistry and real-time polymerase chain reaction. RESULTS: Using cDNA microarrays, we identified the up-regulation of genes involved in the transforming growth factor (TGF)-beta and Wnt-Frizzled pathways, and of thrombospondin (TSP) 4, a member of a cell-migration molecule family, all candidates for involvement in urethral tube formation. Immunohistochemistry showed TGFbeta1, TGFbeta receptor III, and Frizzled1 were expressed exclusively in E14-E17 urethral epithelium. TSP4 was expressed in the mesenchymal basal layer underlying E17 GT skin epidermis. CONCLUSIONS: Many signalling pathways are involved in late GT development, and cell migration molecules might have an important role in urethral tube formation.

Animals↗

Identification of specific gene expression profiles in human mast cells mediated by Toll-like receptor 4 and FcepsilonRI.

Rodent mast cells (MCs) are reported to play a pivotal role in both innate and adaptive immunity. However, there is so far no evidence that human MCs are involved in innate immunity. We found that a functional Toll-like receptor 4 (TLR4) was expressed on human MCs when it was up-regulated by interferon gamma (IFN-gamma). To systematically explore how human MCs modulate the immune system following TLR4-mediated activation and FcepsilonRI aggregation, we used high-density oligonucleotide probe arrays (GeneChip) to compare the lipopolysaccharide (LPS)-induced gene expression profile with the IgE/anti-IgE-mediated profile in MCs. Both a shared core response, and LPS- or anti-IgE-specific programs of gene expression were observed in MCs. Furthermore, MCs exhibited an antiviral response gene program in response to IFN-gamma, and LPS sustained that expression. Compared with the LPS-stimulated gene expression profile of human peripheral blood mononuclear cells, LPS-stimulated MCs specifically induced a subset of genes that included a Th2 cytokine and chemokines that recruit Th2 cells and eosinophils. These results reveal that human MCs express tailored pathogen- and antigen-specific immune responses and that human MCs may play important roles in innate and adaptive immunity.

Chemokine CCL1↗

The use of microarray analysis to determine the gene expression profiles of Mycobacterium tuberculosis in response to anti-bacterial compounds.

The response of Mycobacterium tuberculosis to six anti-microbial agents was determined by microarray analysis in an attempt to define mechanisms of innate resistance in M. tuberculosis. The gene expression profiles of M. tuberculosis after treatment at the minimal inhibitory concentration (MIC) for 4 h with isoniazid, isoxyl, tetrahydrolipstatin, SRI#221, SR1#967 and SR1#9190 were compared to untreated M. tuberculosis. A common response to drug exposure was defined, and this expression profile overlapped with a number of other mycobacterial stress responses recently identified by microarray analysis. Compound-specific responses were also distinguished including a number of putative transcriptional regulators and translocation-related genes. These genes may contribute to the intrinsic resistance of M. tuberculosis to anti-microbial compounds. Further investigation into these mechanisms may elucidate novel pathways contributing to mycobacterial drug resistance and influence anti-mycobacterial drug development strategies.

Antitubercular Agents↗

Looking beyond morphology: cancer gene expression profiling using DNA microarrays.

Although molecular testing has been increasingly used in clinical practice, the precise diagnosis and prognosis of most human cancers still heavily rely on descriptive histopathological data. Identification of robust molecular markers associated with distinctive morphological parameters will assist in diagnostic and prognostic assessment. On the other hand, the diversity of morphologically identical/similar cancers can be manifested at multiple levels, most importantly at the level of clinical outcome. In the past several years, DNA microarray technology has been widely used in the context of cancer research, resulting in a deluge of new information that can be used to identify molecular alterations common to all tumors as well as signatory profiles unique to a subcategory of cancers. These new findings will very likely transform the clinical management of cancer patients in the near term. This article reviews recent advances in cancer gene expression-profiling results derived from the application of DNA microarray technology, with an emphasis on studies performed on human prostate cancer specimens. We discuss broad issues relevant to cancer expression profiling and attempt to illustrate the rapid pace of novel discoveries using prostate cancer as examples wherever appropriate.

DNA, Neoplasm↗

Analysis of expression profile of mammalian cell entry (mce) operons of Mycobacterium tuberculosis.

The sequencing of the complete genome of M. tuberculosis H37Rv has resulted in the recognition of four mce operons in its genome by in silico analysis. In an attempt to understand the significance of the redundancy of mce operons, we analyzed the expression profile of mce operons after different periods of growth in culture as well as during in vivo infection. Our results strongly suggest that mce1 is expressed as a polycistronic message. In culture from day 8 to day 12, expression of only mce1 was observed, but as the cultures progress towards stationary phase the expression profile of mce operons was altered; the transcripts of the mce1 operon were barely detected while those of the mce4 operon were prominent. In an analysis of the expression of mce operons in tubercle material collected from infected animal tissues, we detected the expression of mce1, -3 and -4. Our results imply that mce operons other than mce1 are also expressed during infection and that it is necessary to examine their role in pathogenesis.

Animals↗

Gene expression profiling in breast cancer: understanding the molecular basis of histologic grade to improve prognosis.

BACKGROUND: Histologic grade in breast cancer provides clinically important prognostic information. However, 30%-60% of tumors are classified as histologic grade 2. This grade is associated with an intermediate risk of recurrence and is thus not informative for clinical decision making. We examined whether histologic grade was associated with gene expression profiles of breast cancers and whether such profiles could be used to improve histologic grading. METHODS: We analyzed microarray data from 189 invasive breast carcinomas and from three published gene expression datasets from breast carcinomas. We identified differentially expressed genes in a training set of 64 estrogen receptor (ER)-positive tumor samples by comparing expression profiles between histologic grade 3 tumors and histologic grade 1 tumors and used the expression of these genes to define the gene expression grade index. Data from 597 independent tumors were used to evaluate the association between relapse-free survival and the gene expression grade index in a Kaplan-Meier analysis. All statistical tests were two-sided. RESULTS: We identified 97 genes in our training set that were associated with histologic grade; most of these genes were involved in cell cycle regulation and proliferation. In validation datasets, the gene expression grade index was strongly associated with histologic grade 1 and 3 status; however, among histologic grade 2 tumors, the index spanned the values for histologic grade 1-3 tumors. Among patients with histologic grade 2 tumors, a high gene expression grade index was associated with a higher risk of recurrence than a low gene expression grade index (hazard ratio = 3.61, 95% confidence interval = 2.25 to 5.78; P < .001, log-rank test). CONCLUSIONS: Gene expression grade index appeared to reclassify patients with histologic grade 2 tumors into two groups with high versus low risks of recurrence. This approach may improve the accuracy of tumor grading and thus its prognostic value.

Breast Neoplasms↗

Gene expression profiling of leukemic cell lines reveals conserved molecular signatures among subtypes with specific genetic aberrations.

Hematologic malignancies are characterized by fusion genes of biological/clinical importance. Immortalized cell lines with such aberrations are today widely used to model different aspects of leukemogenesis. Using cDNA microarrays, we determined the gene expression profiles of 40 cell lines as well as of primary leukemias harboring 11q23/MLL rearrangements, t(1;19)[TCF3/PBX1], t(12;21)[ETV6/RUNX1], t(8;21)[RUNX1/CBFA2T1], t(8;14)[IGH@/MYC], t(8;14)[TRA@/MYC], t(9;22)[BCR/ABL1], t(10;11)[PICALM/MLLT10], t(15;17)[PML/RARA], or inv(16)[CBFB/MYH11]. Unsupervised classification revealed that hematopoietic cell lines of diverse origin, but with the same primary genetic changes, segregated together, suggesting that pathogenetically important regulatory networks remain conserved despite numerous passages. Moreover, primary leukemias cosegregated with cell lines carrying identical genetic rearrangements, further supporting that critical regulatory pathways remain intact in hematopoietic cell lines. Transcriptional signatures correlating with clinical subtypes/primary genetic changes were identified and annotated based on their biological/molecular properties and chromosomal localization. Furthermore, the expression profile of tyrosine kinase-encoding genes was investigated, identifying several differentially expressed members, segregating with primary genetic changes, which may be targeted with tyrosine kinase inhibitors. The identified conserved signatures are likely to reflect regulatory networks of importance for the transforming abilities of the primary genetic changes and offer important pathogenetic insights as well as a number of targets for future rational drug design.

Acute Disease↗

Gene expression profiling of cerebellar development with high-throughput functional analysis.

We measured the expression levels of 450 genes during mouse postnatal cerebellar development by quantitative PCR using RNA purified from layers of the cerebellar cortex. Principal component analysis of the data matrix demonstrated that the first and second components corresponded to general levels of gene expression and gene expression patterns, respectively. We introduced 288 of the 450 genes into PC12 cells using a high-throughput transfection assay based on atelocollagen and determined the ability of each gene to promote neurite outgrowth or cell proliferation. Five genes induced neurite outgrowth, and seven genes enhanced proliferation. Evaluation of the functional data and gene expression patterns showed that none of these genes exhibited elevated expression at maturation, suggesting that genes characteristic of mature neurons are not likely to participate in neuronal development. These results demonstrate that functional data can facilitate interpretation of expression profiles and identification of new molecules that participate in biological processes.

Animals↗

Gene expression profiles of progressive pancreatic endocrine tumours and their liver metastases reveal potential novel markers and therapeutic targets.

The intrinsic nature of tumour behaviour (stable vs progressive) and the presence of liver metastases are key factors in determining the outcome of patients with a pancreatic endocrine tumour (PET). Previous expression profile analyses of PETs were limited to non-homogeneous groups or to primary lesions only. The aim of this study was to investigate the gene expression profiles of a more uniform series of sporadic, non-functioning (NF) PETs with progressive disease and, for the first time, their liver metastases, on the Affymetrix human genome U133A and B GeneChip set. Thirteen NF PET samples (eight primaries and five liver metastases) from ten patients with progressive, metastatic disease, three cell lines (BON, QGP and CM) and four purified islet samples were analysed. The same samples were employed for confirmation of candidate gene expression by means of quantitative RT-PCR, while a further 37 PET and 15 carcinoid samples were analysed by immunohistochemistry. Analysis of genes differentially expressed between islets and primaries and metastases revealed 667 up- and 223 down-regulated genes, most of which have not previously been observed in PETs, and whose gene ontology molecular function has been detailed. Overexpression of bridging integrator 1 (BIN1) and protein Z dependent protease inhibitor (SERPINA10) which may represent useful biomarkers, and of lymphocyte specific protein tyrosine kinase (LCK) and bone marrow stromal cell antigen (BST2) which could be used as therapeutic targets, has been validated. When primary tumours were compared with metastatic lesions, no significantly differentially expressed genes were found, in accord with cluster analysis which revealed a striking similarity between primary and metastatic lesions, with the cell lines clustering separately. We have provided a comprehensive list of differentially expressed genes in a uniform set of aggressive NF PETs. A number of dysregulated genes deserve further in-depth study as potentially promising candidates for new diagnostic and treatment strategies. The analysis of liver metastases revealed a previously unknown high level of similarity with the primary lesions.

Adult↗

Expression profile analysis of neurodegenerative disease: advances in specificity and resolution.

Microarray technology has become a common tool for developing expression profiles. Initially used in the analysis of cells lines and homogeneous tissues, this platform has been applied to more diverse tissues, such as the brain. Several neural disorders have already been profiled by microarrays using relatively large amounts of tissue. This data has unveiled many genes with differential expression between normal and diseased tissue that could potentially be used as gene markers for these afflictions. Because of the heterogeneity of the CNS, it is likely that small differences between gene expression in these studies would be enhanced by the sampling of a subset of cells based on these newly characterized gene markers. Subtraction of normal, unaffected cells from the sample may also result in a more accurate profile of a diseased cell. Expression profile studies from several neuropathological states are presented, with emphasis placed on those studies using small samples of cellular material and those using specialized methods of cell isolation and RNA amplification.

AIDS Dementia Complex↗

Classification of human lung carcinomas by mRNA expression profiling reveals distinct adenocarcinoma subclasses.

We have generated a molecular taxonomy of lung carcinoma, the leading cause of cancer death in the United States and worldwide. Using oligonucleotide microarrays, we analyzed mRNA expression levels corresponding to 12,600 transcript sequences in 186 lung tumor samples, including 139 adenocarcinomas resected from the lung. Hierarchical and probabilistic clustering of expression data defined distinct subclasses of lung adenocarcinoma. Among these were tumors with high relative expression of neuroendocrine genes and of type II pneumocyte genes, respectively. Retrospective analysis revealed a less favorable outcome for the adenocarcinomas with neuroendocrine gene expression. The diagnostic potential of expression profiling is emphasized by its ability to discriminate primary lung adenocarcinomas from metastases of extra-pulmonary origin. These results suggest that integration of expression profile data with clinical parameters could aid in diagnosis of lung cancer patients.

Adenocarcinoma↗

Surface-antigen expression profiling (SEP) in B-cell chronic lymphocytic leukemia (B-CLL): Identification of markers with prognostic relevance.

Studies of gene expression profiling (GEP) have been successfully used for the identification of molecules to be employed as potential prognosticators. With the aim of identifying the immunophenotypic profile of B-CLL subsets with different prognoses, we investigated by flow cytometry the expression of 36 surface antigens in 117 cases, 113 with survival data. In analogy with GEP, results were analyzed by applying unsupervised hierarchical algorithms (surface-antigen expression profiling, SEP). Distinct immunophenotypic groups (A, B1, B2 and C) were identified, group C (57/117) with longer survivals, as compared to groups A (23/117), B1 (16/117) and B2 (21/117). The immunophenotypic signatures of these groups were characterized by the coordinated and differential over-expression of: i) CD62L, CD54 and CD49c (group C); ii) CD38 and CD49d (group A); iii) none of the above markers (group B1 and B2). Other molecules were either not expressed, widely expressed by all samples, or were variably expressed within the observed B-CLL subgroups, although without a clearly distinguishable pattern. By employing an identical approach for investigating the reactivity of B-cell panel monoclonal antibodies (B-mAbs) in B-CLLs (29 cases) and in 19 B and non-B leukemia/lymphoma cell lines, we found mAbs (B012, B001, B006, B018, B019, B020, B017) mainly unreactive in all the samples, mAbs (B002, B010, B013, B014, B015) strongly reactive in B-CLLs and B-cell lines but not in non-B-cell lines, and mAbs recognizing antigens variably expressed in cell lines and B-CLLs. A hierarchical clustering focused on B-CLLs alone, combining reactivity values for B-mAbs with the expression of CD62L and CD38, these latter antigens identified as leader markers of B-CLL subsets with different prognosis, demonstrated a correlation between CD62L expression and the reactivity of B007, B003, B011 and B005 mAbs. These mAbs may represent potentially novel markers with prognostic relevance in B-CLLs.

ADP-ribosyl Cyclase 1↗

Gene expression profiling of 1p35-36 genes in neuroblastoma.

Deletion of the chromosome 1p36 region is a frequent abnormality in neuroblastoma. To gain further insights into the role of this alteration in oncogenesis, we have constructed a specific cDNA microarray representing most known genes and ESTs from the 1p35-36 region and analysed the expression profiles of 15 neuroblastoma cell lines and 28 neuroblastoma tumours. Hierarchical clustering using expression levels of 320 cDNAs from 1p35-36 separated localized or 4S cases without 1p deletion from advanced stages and cell lines. Supervised learning classification enabled to predict reliably the status of chromosome 1p according to its expression profile. Around 15% of the genes or ESTs presented a significantly decreased expression in samples with 1p deletion as compared to 1p-normal samples suggesting that 1p deletion results in a gene dosage effect on a subset of genes critical for the development of 1p-deleted neuroblastoma. Several genes presumed to have functions in neural differentiation (CDC42, VAMP3, CLSTN1), signal transduction in neural cells (GNB1) and cell cycle regulation (STMN1, RPA2, RBAF600, FBXO6, MAD2L2) exhibited a decreased expression in samples presenting 1p deletion. The identification of such genes provides baseline information for further studies to elucidate how these genes could individually or collectively play a critical role in neuroblastoma tumorigenesis.

Cell Line, Tumor↗

Gene expression profiling of cancer progression reveals intrinsic regulation of transforming growth factor-beta signaling in ErbB2/Neu-induced tumors from transgenic mice.

Upregulation of HER2/ErbB2/Neu occurs in 15-30% of human breast cancers and correlates with poor prognosis. Identification of ErbB2/Neu transcriptional targets should facilitate development of novel therapeutic approaches. Development of breast cancer is a multistep process; thus, to identify the transcriptomes associated with different stages of progression of tumorigenesis, we compared expression profiles of mammary tumors and preneoplastic mammary tissue from MMTV-Neu transgenic mice to expression profiles of wild-type mammary glands using Affymetrix microarrays. We identified 324 candidate genes that were unique to ErbB2/Neu-induced tumors relative to normal mammary gland tissue from wild-type controls. Expression of a subset of these genes (82) was also changed in the preneoplastic mammary glands compared to wild-type controls, indicating that they may play a pivotal role during early events of ErbB2/Neu-initiated mammary tumorigenesis. Further analysis of the microarray data revealed that expression of several known transforming growth factor (TGF)-beta target genes was altered, suggesting that the TGF-beta signaling cascade is downregulated in ErbB2/Neu-induced tumors. Western blot analysis for TGF-beta-Receptor-I/ALK5 and immunohistochemistry for TGF-beta-Receptor-I/ALK5 and phosphorylated/activated Smad2 confirmed that the Smad-dependent TGF-beta signaling cascade was inactive in these tumors. Although absent in most of the tumor, phosphorylated Smad2 was present in the periphery of tumors. Interestingly, presence of phosphorylated/activated Smad2 correlated with expression of Activin-Receptor-IB/ALK4, suggesting that although Smad-dependent TGF-beta signaling is absent in ErbB2/Neu-induced tumors, Activin signaling may be active at the leading edge of these tumors. Cumulatively, these data indicate that the TGF-beta pathway is intrinsically suppressed in ErbB2/Neu tumors via a mechanism involving loss of TGF-beta-Receptor-I/ALK5.

Activin Receptors↗

[Changes in apoptosis-related genes expression profile in human breast carcinoma cell line Bcap-37 induced by flavonoids from seed residues of Hippophae Rhamnoides L].

BACKGROUND & OBJECTIVE: Hippophae rhamnoides L. possesses functions of antioxidation and radioprotection. This study was designed to investigate changes in apoptosis-related genes expression profile in human breast carcinoma cell line Bcap-37 induced by flavonoids from seed residues of Hippophae rhamnoides L. (FHR) with cDNA microarray, and to explore possible mechanism of signal transduction on apoptosis. METHODS: Total RNA was extracted from Bcap-37 cells before and after treatment of FHR. Two cDNA probes, labeled by Cy3-dUTP or Cy5-dUTP fluorescent dyes, were synthesized via reverse transcription, and hybridized with a microarray contained 13 824 human 14K cDNA. Differential gene expression profiles of FHR group and control group were analyzed by Genespring software. RESULTS: After treatment of FHR, 305 genes were up-regulated, and 361 were down-regulated; 32 apoptosis-related genes were differentially expressed, and accounted for 0.23% of the total genes in cDNA microarray. Of the 32 apoptosis-related genes, 25 were up-regulated (average Ratio: 3.071), and 7 were down-regulated (average Ratio: 0.418). Bioinformatic analyses showed that the 32 genes, including CTNNB1, TSSC3, IGFBP4, IGFBP6, GADD34, TNFRSF10B, Caspase-9, and PCNA, related with apoptosis of Bcap-37 cells when treated with FHR. CONCLUSION: Apoptosis of Bcap-37 cells induced by FHR relates with various genes through co-regulating of intracellular and extracellular signal transduction pathways.

Apoptosis↗

New expression profiles of voltage-gated ion channels in arteries exposed to high blood pressure.

The diameters of small arteries and arterioles are tightly regulated by the dynamic interaction between Ca(2+) and K(+) channels in the vascular smooth muscle cells. Calcium influx through voltage-gated Ca(2+) channels induces vasoconstriction, whereas the opening of K(+) channels mediates hyperpolarization, inactivation of voltage-gated Ca(2+) channels, and vasodilation. Three types of voltage-sensitive ion channels have been highly implicated in the regulation of resting vascular tone. These include the L-type Ca(2+) (Ca(L)) channels, voltage-gated K(+) (K(V)) channels, and high-conductance voltage- and Ca(2+)-sensitive K(+) (BK(Ca)) channels. Recently, abnormal expression profiles of these ion channels have been identified as part of the pathogenesis of arterial hypertension and other vasospastic diseases. An increasing number of studies suggest that high blood pressure may trigger cellular signaling cascades that dynamically alter the expression profile of arterial ion channels to further modify vascular tone. This article will briefly review the properties of Ca(L), K(V), and BK(Ca) channels, present evidence that their expression profile is altered during systemic hypertension, and suggest potential mechanisms by which the signal of elevated blood pressure may result in altered ion channel expression. A final section will discuss emerging concepts and opportunities for the development of new vasoactive drugs, which may rely on targeting disease-specific changes in ion channel expression as a mechanism to lower vascular tone during hypertensive diseases.

Arteries↗