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Quantitative RT-PCR Analysis (quantitative + rt-pcr_analysis)
Selected AbstractsLoss of Nkx3.1 expression in the transgenic adenocarcinoma of mouse prostate modelTHE PROSTATE, Issue 16 2007Carlise R. Bethel Abstract BACKGROUND The transgenic adenocarcinoma of mouse prostate (TRAMP) model has been extensively characterized at the histological and molecular levels, and has been shown to mimic significant features of human prostate cancer. However, the status of Nkx3.1 expression in the TRAMP model has not been elucidated. METHODS Immunohistochemical analyses were performed using dorsal, lateral, and ventral prostate (VP) lobes from ages 6 to 30 weeks. Quantitative RT-PCR analyses were performed to determine relative mRNA expression. RESULTS Heterogeneous loss of Nkx3.1 was observed in hyperplastic lesions of the ventral, dorsal, and lateral lobes. At 6 weeks of age, the ventral lobe displayed profound loss of Nkx3.1. Diminished Nkx3.1 protein was observed in well- to moderately-differentiated cancer lesions of all lobes. Poorly differentiated (PD) tumors stained negatively for Nkx3.1. Quantitative RT-PCR analyses revealed the presence of Nkx3.1 mRNA in each lobe at all ages, albeit reduced to variable levels. CONCLUSIONS These data suggest that disease progression in the TRAMP model may be driven by loss of function of Nkx3.1, in addition to p53 and Rb. Lobe-specific disease progression in the TRAMP model correlates with the reduction of Nkx3.1 protein. Regulation of Nkx3.1 expression during tumorigenesis appears to occur by post-transcriptional and post-translational mechanisms. Prostate 67: 1740,1750, 2007. © 2007 Wiley-Liss, Inc. [source] Alterations of 3p21.31 tumor suppressor genes in head and neck squamous cell carcinoma: Correlation with progression and prognosisINTERNATIONAL JOURNAL OF CANCER, Issue 11 2008Susmita Ghosh Abstract The aim of our study was to analyze the alterations of some candidate tumor suppressor genes (TSGs) viz. LIMD1, LTF, CDC25A, SCOTIN, RASSF1A and CACNA2D2 located in the chromosomal region 3p21.31 associated with the development of early dysplastic lesions of head and neck. In analysis of 72 dysplastic lesions and 116 squamous cell carcinoma of head and neck, both deletion and promoter methylation have been seen in these genes except for CDC25A and SCOTIN where no methylation has been detected. The alteration of LIMD1 was highest (50%) in the mild dysplastic lesions and did not change significantly during progression of tumor indicating its association with this stage of the disease. It was evident that alterations of LTF, CDC25A and CACNA2D2 were associated with development of moderate dysplastic lesions, while alterations in RASSF1A and CACNA2D2 were needed for progression. Novel somatic mutations were seen in exon 1 of LIMD1 (7%), intron 3/exon4 splice junction of LTF (2%) and exon 7 of cdc25A (10%). Quantitative RT-PCR analysis revealed mean reduced expression of the genes in the following order: LTF (67.6 ± 16.8) > LIMD1 (53.2 ± 20.1) > CACNA2D2 (23.7 ± 7.1) > RASSF1A (15.1 ± 5.6) > CDC25A (5.3 ± 2.3) > SCOTIN (0.58 ± 0.54). Immunohistochemical analysis of CDC25A showed its localization both in cytoplasm and nucleus in primary lesions and oral cancer cell lines. In absence of HPV infection, LTF and RASSF1A alterations jointly have adverse impact on survival of tobacco addicted patients. Thus, our data suggested that multiple candidate TSGs in the chromosomal 3p21.31 region were differentially associated with the early dysplastic lesions of head and neck. © 2008 Wiley-Liss, Inc. [source] cAMP activation by PACAP/VIP stimulates IL-6 release and inhibits osteoblastic differentiation through VPAC2 receptor in osteoblastic MC3T3 cellsJOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2009Azusa Nagata The neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP), a member of the glucagon/vasoactive intestinal peptide (VIP) superfamily, stimulates cyclic AMP accumulation initiating a variety of biological processes such as: neurotropic actions, immune and pituitary function, learning and memory, catecholamine biosynthesis and regulation of cardiopulmonary function. Both osteoclasts and osteoblasts have been shown to express receptors for PACAP/VIP implicated in their role in bone metabolism. To further understand the role of PACAP/VIP family in controlling bone metabolism, we investigated differentiation model of MC3T3-E1 cells, an osteoblastic cell line derived from mouse calvaria. Quantitative RT-PCR analysis demonstrated that MC3T3-E1 cells expressed only VPAC2 receptor and its expression was upregulated during osteoblastic differentiation, whereas VPAC1 and PAC1 receptors were not expressed. Consistent with expression of receptor subtype, both PACAP and VIP stimulate cAMP accumulation in a time- and dose-dependent manner with the similar potency in undifferentiated and differentiated cells, while Maxadilan, a specific agonist for PAC1-R, did not. Furthermore, downregulation of VPAC2-R by siRNA completely blocked cAMP response mediated by PACAP and VIP. Importantly, PACAP/VIP as well as forskolin markedly suppressed the induction of alkaline phosphatase mRNA upon differentiation and the pretreatment with 2,,5,-dideoxyadenosine, a cAMP inhibitor, restored its inhibitory effect of PACAP. We also found that PACAP and VIP stimulated IL-6 release, a stimulator of bone resorption, and VPAC2-R silencing inhibited IL-6 production. Thus, PACAP/VIP can activate adenylate cyclase response and regulate IL-6 release through VPAC2 receptor with profound functional consequences for the inhibition of osteoblastic differentiation in MC3T3-E1 cells. J. Cell. Physiol. 221: 75,83, 2009. © 2009 Wiley-Liss, Inc [source] Quantitative RT-PCR analysis of estrogen receptor gene expression in laser microdissected prostate cancer tissueTHE PROSTATE, Issue 8 2009Thomas J. Walton Abstract BACKGROUND Real-time quantitative RT-PCR analysis of laser microdissected tissue is considered the most accurate technique for determining tissue gene expression. The discovery of estrogen receptor beta (ER,) has focussed renewed interest on the role of estrogen receptors in prostate cancer, yet few studies have utilized the technique to analyze estrogen receptor gene expression in prostate cancer. METHODS Fresh tissue was obtained from 11 radical prostatectomy specimens and from 6 patients with benign prostate hyperplasia. Pure populations of benign and malignant prostate epithelium were laser microdissected, followed by RNA isolation and electrophoresis. Quantitative RT-PCR was performed using primers for androgen receptor (AR), estrogen receptor beta (ER,), estrogen receptor alpha (ER,), progesterone receptor (PGR) and prostate specific antigen (PSA), with normalization to two housekeeping genes. Differences in gene expression were analyzed using the Mann,Whitney U -test. Correlation coefficients were analyzed using Spearman's test. RESULTS Significant positive correlations were seen when AR and AR-dependent PSA, and ER, and ER,-dependent PGR were compared, indicating a representative population of RNA transcripts. ER, gene expression was significantly over-expressed in the cancer group compared with benign controls (P,<,0.01). In contrast, PGR expression was significantly down-regulated in the cancer group (P,<,0.05). There were no significant differences in AR, ER, or PSA expression between the groups. This study represents the first to show an upregulation of ER, gene expression in laser microdissected prostate cancer specimens. CONCLUSIONS In concert with recent studies the findings suggest differential production of ER, splice variants, which may play important roles in the genesis of prostate cancer. Prostate 69: 810,819, 2009. © 2009 Wiley-Liss, Inc. [source] A single nucleotide polymorphism at the splice donor site of the human MYH base excision repair gene results in reduced translation efficiency of its transcriptsGENES TO CELLS, Issue 5 2002Satoru Yamaguchi Background: Adenine paired with 8-hydroxyguanine, a major oxidatively damaged DNA lesion, is excised by mutY homologue (MYH) base excision repair protein in human cells. Since genetic polymorphisms of DNA repair genes associated with the activities and the expression levels of their products may modulate cancer susceptibility of individuals, we investigated the effect of a single nucleotide polymorphism (SNP) in the MYH gene on the difference in the expression levels of its products. Results: An aberrant size of the , type nuclear form transcript was detected in a lung cancer cell line, VMRC-LCD, by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. The transcript contained the intron 1 sequence, and it was due to alternative splicing resulting from IVS1+5G/C SNP. The presence of the upstream open reading frame (ORF) on the 5,-side of the native ORF in the , type transcript from the IVS1+5C allele could reduce the translation efficiency of the transcript into the nuclear form protein. Thus, expression vectors bearing the 5,-untranslated region sequence of either the IVS1+5G or 5C allele were constructed. In vitro translation analysis, as well as Western blot and quantitative RT-PCR analyses of the H1299 lung cancer cell line transfected with these vectors, revealed that the translation efficiency of the IVS1+5C transcript into MYH protein was much lower (, 30%) than that of the IVS1+5G transcript. Conclusions: The SNP at the splice donor site of the MYH gene resulted in reduced translation efficiency of its transcripts. This is the fourth case of single nucleotide variations that cause alterations in translation initiation sites and translation efficiencies in human cells. [source] BimEL as a possible molecular link between proteasome dysfunction and cell death induced by mutant huntingtinEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2010Rebecca Leon Abstract Huntington's disease (HD) is a devastating neurodegenerative disorder caused by an expanded polyglutamine repeat within the N-terminus of the huntingtin protein. It is characterized by a selective loss of medium spiny neurons in the striatum. It has been suggested that impaired proteasome function and endoplasmic reticulum (ER) stress play important roles in mutant huntingtin (mHtt)-induced cell death. However, the molecular link involved is poorly understood. In the present study, we identified the essential role of the extra long form of Bim (Bcl-2 interacting mediator of cell death), BimEL, in mHtt-induced cell death. BimEL protein expression level was significantly increased in cell lines expressing the N-terminus of mHtt and in a mouse model of HD. Although quantitative RT-PCR analysis indicated that BimEL mRNA was increased in cells expressing mHtt, we provided evidence showing that, at the post-translational level, phosphorylation of BimEL played a more important role in regulating BimEL expression. Up-regulation of BimEL facilitated the translocation of Bax to the mitochondrial membrane, which further led to cytochrome c release and cell death. On the other hand, knocking down BimEL expression prevented mHtt-induced cell death. Taken together, these findings suggest that BimEL is a key element in regulating mHtt-induced cell death. A model depicting the role of BimEL in linking mHtt-induced ER stress and proteasome dysfunction to cell death is proposed. [source] Gene Expression Profiling in Cluster Headache: A Pilot Microarray StudyHEADACHE, Issue 10 2006Christina Sjöstrand MD Background.,Cluster headache (CH) is a primary neurovascular headache disorder characterized by attacks of excruciating pain accompanied by ipsilateral autonomic symptoms. CH pathophysiology is presumed to involve an activation of hypothalamic and trigeminovascular systems, but inflammation and immunological mechanisms have also been hypothesized to be of importance. Objective.,To identify differentially expressed genes during different clinical phases of CH, assuming that changes of pathophysiological importance would also be seen in peripheral venous blood. Methods.,Blood samples were drawn at 3 consecutive occasions from 3 episodic CH patients: during attacks, between attacks and in remission, and at 1 occasion from 3 matched controls. Global gene expression was analyzed with microarray tehnology using the Affymetrix Human Genome U133 2.0 Plus GeneChip® Set, covering more than 54,000 gene transcripts, corresponding to almost 22,000 genes. Quantitative RT-PCR on S100P gene expression was analyzed in 6 patients and 14 controls. Results.,Overall, quite small differences were seen intraindividually and large differences interindividually. However, pairwise comparisons of signal values showed upregulation of several S100 calcium binding proteins; S100A8 (calgranulin A), S100A12 (calgranulin C), and S100P during active phase of the disease compared to remission. Also, annexin A3 (calcium-binding) and ICAM3 showed upregulation. BIRC1 (neuronal apoptosis inhibitory protein), CREB5, HLA-DQA1, and HLA-DQB1 were upregulated in patients compared to controls. The upregulation of S100P during attack versus remission was confirmed by quantitative RT-PCR analysis. Conclusions.,The S100A8 and S100A12 proteins are considered markers of non-infectious inflammatory disease, while the function of S100P is still largely unknown. Furthermore, upregulation of HLA-DQ genes in CH patients may also indicate an inflammatory response. Upregulation of these pro-inflammatory genes during the active phase of CH has not formerly been reported. Data from this pilot microarray study provide a basis for further studies in CH. [source] MRNA differential display identification of thyroid hormone-responsive protein (THRP) gene in association with early phase of long-term potentiationHIPPOCAMPUS, Issue 6 2001Y.P. Tang Abstract The process of long-term potentiation (LTP) consists of the early induction and late maintenance phases. Few studies have examined the cellular mechanisms underlying these two phases; their respective mRNA expression profiles have not yet been elucidated. Here we used the technique of PCR differential display to identify genes that are differentially expressed between the early and late phases of LTP in vivo. Our results indicated that the cDNA fragment corresponding to one mRNA with preferentially increased expression during the early, but not late, phase of LTP encodes the rat thyroid hormone-responsive protein (THRP) gene. In situ hybridization analysis confirmed the results obtained from the PCR differential display. Prior NMDA receptor blockade with MK801 prevented induction of LTP and decreased THRP mRNA expression in the dentate gyrus, as assayed by quantitative RT-PCR analysis. THRP antisense oligonucleotide treatment before tetanic stimulation also prevented induction of LTP. However, when THRP antisense oligonucleotide was administered after induction of LTP, it did not affect expression and maintenance of LTP. THRP is known to be responsive to thyroid hormone. Our results indicate that direct thyroid hormone (T3) injection into the dentate gyrus produces a long-lasting enhancement of synaptic efficacy of these neurons. T3 injection also markedly increased THRP mRNA expression in the dentate gyrus. Taken together, our results suggest that THRP mRNA expression plays an important role in the early phase, but not the late phase, of LTP and that both THRP and thyroid hormone are involved in synaptic plasticity in hippocampal neurons. Hippocampus 2001;11:637,646. © 2001 Wiley-Liss, Inc. [source] Identification of Novel Regulators Associated With Early-Phase Osteoblast Differentiation,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2004Diana S de Jong Abstract Key regulatory components of the BMP-induced osteoblast differentiation cascade remain to be established. Microarray and subsequent expression analyses in mice identified two transcription factors, Hey1 and Tcf7, with in vitro and in vivo expression characteristics very similar to Cbfa1. Transfection studies suggest that Tcf7 modulates BMP2-induced osteoblast differentiation. This study contributes to a better definition of the onset of BMP-induced osteoblast differentiation. Introduction: Elucidation of the genetic cascade guiding mesenchymal stem cells to become osteoblasts is of extreme importance for improving the treatment of bone-related diseases such as osteoporosis. The aim of this study was to identify regulators of the early phases of bone morphogenetic protein (BMP)2-induced osteoblast differentiation. Materials and Methods: Osteoblast differentiation of mouse C2C12 cells was induced by treatment with BMP2, and regulation of gene expression was studied during the subsequent 24 h using high-density microarrays. The regulated genes were grouped by means of model-based clustering, and protein functions were assigned. Real-time quantitative RT-PCR analysis was used to validate BMP2-induced gene expression patterns in C2C12 cells. Osteoblast specificity was studied by comparing these expression patterns with those in C3H10T1/2 and NIH3T3 cells under similar conditions. In situ hybridization of mRNA in embryos at embryonic day (E)14.5 and E16.5 of gestation and on newborn mouse tails were used to study in vivo expression patterns. Cells constitutively expressing the regulated gene Tcf7 were used to investigate its influence on BMP-induced osteoblast differentiation. Results and Conclusions: A total of 184 genes and expressed sequence tags (ESTs) were differentially expressed in the first 24 h after BMP2 treatment and grouped in subsets of immediate early, intermediate early, and late early response genes. Signal transduction regulatory factors mainly represented the subset of immediate early genes. Regulation of expression of these genes was direct, independent of de novo protein synthesis and independent of the cell type studied. The intermediate early and late early genes consisted primarily of genes related to processes that modulate morphology, basement membrane formation, and synthesis of extracellular calcified matrix. The late early genes require de novo protein synthesis and show osteoblast specificity. In vivo and in vitro experiments showed that the transcription factors Hey1 and Tcf7 exhibited expression characteristics and cell type specificity very similar to those of the osteoblast specific transcription factor Cbfa1, and constitutive expression of Tcf7 in C2C12 cells differentially regulated osteoblast differentiation marker genes. [source] Quantitative RT-PCR analysis of estrogen receptor gene expression in laser microdissected prostate cancer tissueTHE PROSTATE, Issue 8 2009Thomas J. Walton Abstract BACKGROUND Real-time quantitative RT-PCR analysis of laser microdissected tissue is considered the most accurate technique for determining tissue gene expression. The discovery of estrogen receptor beta (ER,) has focussed renewed interest on the role of estrogen receptors in prostate cancer, yet few studies have utilized the technique to analyze estrogen receptor gene expression in prostate cancer. METHODS Fresh tissue was obtained from 11 radical prostatectomy specimens and from 6 patients with benign prostate hyperplasia. Pure populations of benign and malignant prostate epithelium were laser microdissected, followed by RNA isolation and electrophoresis. Quantitative RT-PCR was performed using primers for androgen receptor (AR), estrogen receptor beta (ER,), estrogen receptor alpha (ER,), progesterone receptor (PGR) and prostate specific antigen (PSA), with normalization to two housekeeping genes. Differences in gene expression were analyzed using the Mann,Whitney U -test. Correlation coefficients were analyzed using Spearman's test. RESULTS Significant positive correlations were seen when AR and AR-dependent PSA, and ER, and ER,-dependent PGR were compared, indicating a representative population of RNA transcripts. ER, gene expression was significantly over-expressed in the cancer group compared with benign controls (P,<,0.01). In contrast, PGR expression was significantly down-regulated in the cancer group (P,<,0.05). There were no significant differences in AR, ER, or PSA expression between the groups. This study represents the first to show an upregulation of ER, gene expression in laser microdissected prostate cancer specimens. CONCLUSIONS In concert with recent studies the findings suggest differential production of ER, splice variants, which may play important roles in the genesis of prostate cancer. Prostate 69: 810,819, 2009. © 2009 Wiley-Liss, Inc. [source] Distinct pattern of gene expression in pyothorax-associated lymphoma (PAL), a lymphoma developing in long-standing inflammationCANCER SCIENCE, Issue 10 2004Mieko Nishiu Pyothorax-associated lymphoma (PAL) is a unique lymphoma developing in the pleural cavity after long-standing pyothorax. They are diffuse large B-cell lymphomas (DLBCLs), frequently with immunoblastic morphology, and show a strong association with Epstein-Barr virus (EBV) infection. In this study, cDNA microarray analysis was performed in six cases with PAL and 12 with nodal DLBCL. Among 5516 informative genes, 348 displayed more than 2-fold difference (higher or lower) of expression level between PAL and nodal DLBCL (P>0.001). These genes are known to be involved in apoptosis, interferon response, and signal transduction. One of the most differentially expressed genes, IFI27 (interferon-,-inducible protein 27) was subjected to quantitative RT-PCR analysis, and increased expression of IFI27 was confirmed. Over-expression of IFI27 was also found in cell lines derived from PAL, but not in other lymphoid cell lines. This study shows that PAL is a distinctive subtype of DLBCL not only in its clinical presentation, but also in its molecular profile. [source] | |||||||||||||