351
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Erickson HS, Albert PS, Gillespie JW, Wallis BS, Rodriguez-Canales J, Linehan WM, Gonzalez S, Velasco A, Chuaqui RF, Emmert-Buck MR. Assessment of normalization strategies for quantitative RT-PCR using microdissected tissue samples. J Transl Med 2007; 87:951-62. [PMID: 17643124 DOI: 10.1038/labinvest.3700659] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Gene expression measurement techniques such as quantitative reverse transcriptase (qRT)-PCR require a normalization strategy to allow meaningful comparisons across biological samples. Typically, this is accomplished through the use of an endogenous housekeeping gene that is presumed to show stable expression levels in the samples under study. There is concern regarding how precisely specific genes can be measured in limited amounts of mRNA such as those from microdissected (MD) tissues. To address this issue, we evaluated three different approaches for qRT-PCR normalization of dissected samples; cell count during microdissection, total RNA measurement, and endogenous control genes. The data indicate that both cell count and total RNA are useful in calibrating input amounts at the outset of a study, but do not provide enough precision to serve as normalization standards. However, endogenous control genes can accurately determine the relative abundance of a target gene relative to the entire cellular transcriptome. Taken together, these results suggest that precise gene expression measurements can be made from MD samples if the appropriate normalization strategy is employed.
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Affiliation(s)
- Heidi S Erickson
- Pathogenetics Unit, Laboratory of Pathology and Urologic Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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352
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Gozgit JM, Pentecost BT, Marconi SA, Ricketts-Loriaux RSJ, Otis CN, Arcaro KF. PLD1 is overexpressed in an ER-negative MCF-7 cell line variant and a subset of phospho-Akt-negative breast carcinomas. Br J Cancer 2007; 97:809-17. [PMID: 17726467 PMCID: PMC2360386 DOI: 10.1038/sj.bjc.6603926] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
We have used a novel variant of the human oestrogen receptor (ER)-positive MCF-7 cell line, TMX2-28, as a model to study breast cancer. TMX2-28 cells show no detectable levels of mRNA or protein expression for the ER and express basal cytokeratins (CKs) 5, 14, and 17. cDNA microarray comparison between TMX2-28 and its parent cell line, MCF-7, identified 1402 differentially expressed transcripts, one of which was, phospholipase D1 (PLD1). Using real-time RT–PCR, we confirmed that PLD1 mRNA levels are 10-fold higher in TMX2-28 cells than in MCF-7 cells. We next examined PLD1 expression in human breast carcinomas. Phospholipase D1 mRNA levels were higher in breast tumours that expressed high-mRNA levels of basal CKs 5 and/or 17, but PLD1 mRNA levels were not significantly higher in ER-negative tumours. Phospholipase D1 protein was overexpressed in 10 of 42 (24%) breast tumours examined by IHC. Phospholipase D1 was overexpressed in 6 of 31 ER-positive tumours and 4 of 11 ER-negative tumours. Phospholipase D1 was overexpressed in three of the four tumours that showed high CK5/17 expression. Five PLD1-positive tumours were negative for phospho-Akt expression, but positive for phospho-mammalian target of rapamycin (mTOR) expression. The other five PLD1-positive breast tumours showed positive expression for phospho-Akt; however, only two of these cases were positive for phospho-mTOR. In this study, we report that PLD1 and phospho-mTOR are coexpressed in a subset of phospho-Akt-negative breast carcinomas.
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Affiliation(s)
- J M Gozgit
- Department of Veterinary and Animal Sciences, University of Massachusetts, 639 North Pleasant Street, Morrill 1 North, Amherst, MA 01003-9298, USA
| | - B T Pentecost
- Wadsworth Center, New York State Department of Health, Albany, NY 12202, USA
| | - S A Marconi
- Department of Pathology, Baystate Medical Center, Springfield, MA 01199, USA
| | | | - C N Otis
- Department of Pathology, Baystate Medical Center, Springfield, MA 01199, USA
| | - K F Arcaro
- Department of Veterinary and Animal Sciences, University of Massachusetts, 639 North Pleasant Street, Morrill 1 North, Amherst, MA 01003-9298, USA
- E-mail:
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353
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Nygard AB, Jørgensen CB, Cirera S, Fredholm M. Selection of reference genes for gene expression studies in pig tissues using SYBR green qPCR. BMC Mol Biol 2007; 8:67. [PMID: 17697375 PMCID: PMC2000887 DOI: 10.1186/1471-2199-8-67] [Citation(s) in RCA: 374] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Accepted: 08/15/2007] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Real-time quantitative PCR (qPCR) is a method for rapid and reliable quantification of mRNA transcription. Internal standards such as reference genes are used to normalise mRNA levels between different samples for an exact comparison of mRNA transcription level. Selection of high quality reference genes is of crucial importance for the interpretation of data generated by real-time qPCR. RESULTS In this study nine commonly used reference genes were investigated in 17 different pig tissues using real-time qPCR with SYBR green. The genes included beta-actin (ACTB), beta-2-microglobulin (B2M), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), hydroxymethylbilane synthase (HMBS), hypoxanthine phosphoribosyltransferase 1 (HPRT1), ribosomal protein L4 (RPL4), succinate dehydrogenase complex subunit A (SDHA), TATA box binding protein (TPB)and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta polypeptide (YWHAZ). The stability of these reference genes in different pig tissues was investigated using the geNorm application. The range of expression stability in the genes analysed was (from the most stable to the least stable): ACTB/RPL4, TBP, HPRT, HMBS, YWHAZ, SDHA, B2M and GAPDH. CONCLUSION Expression stability varies greatly between genes. ACTB, RPL4, TPB and HPRT1 were found to have the highest stability across tissues. Based on both expression stability and expression level, our data suggest that ACTB and RPL4 are good reference genes for high abundant transcripts while TPB and HPRT1 are good reference genes for low abundant transcripts in expression studies across different pig tissues.
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Affiliation(s)
- Ann-Britt Nygard
- University of Copenhagen, Faculty of Life Sciences, Department of Basic Animal and Veterinary Sciences, Division of Genetics and Bioinformatics, Groennegaardsvej 3, 1870 Frederiksberg C, Denmark
| | - Claus B Jørgensen
- University of Copenhagen, Faculty of Life Sciences, Department of Basic Animal and Veterinary Sciences, Division of Genetics and Bioinformatics, Groennegaardsvej 3, 1870 Frederiksberg C, Denmark
| | - Susanna Cirera
- University of Copenhagen, Faculty of Life Sciences, Department of Basic Animal and Veterinary Sciences, Division of Genetics and Bioinformatics, Groennegaardsvej 3, 1870 Frederiksberg C, Denmark
| | - Merete Fredholm
- University of Copenhagen, Faculty of Life Sciences, Department of Basic Animal and Veterinary Sciences, Division of Genetics and Bioinformatics, Groennegaardsvej 3, 1870 Frederiksberg C, Denmark
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354
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Gopee NV, Howard PC. A time course study demonstrating RNA stability in postmortem skin. Exp Mol Pathol 2007; 83:4-10. [PMID: 17174950 DOI: 10.1016/j.yexmp.2006.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2006] [Revised: 11/08/2006] [Accepted: 11/08/2006] [Indexed: 11/22/2022]
Abstract
Knowledge of the factors regulating the rate of mRNA degradation, including postmortem delay, is important in determining the reliability of gene expression patterns in dermal tissue. Since RNA stability can be tissue dependent, this study evaluates the effect of postmortem interval on the integrity of total RNA or the levels of representative mRNA species in murine cutaneous tissue. Pieces of fresh skin tissue were excised for periods of 0-60 min from SKH-1 female hairless mice that were maintained at room temperature post-sacrifice. Total RNA was subsequently isolated and RNA integrity from each specimen was evaluated. Bioanalyzer profiles showed no apparent change in 28S/18S rRNA ratio or RNA integrity number at time points up to 60 min. Changes in mRNA expression levels of five selected genes were determined by real-time quantitative PCR. There were no statistical differences in the relative gene expressions of Ccnd1, Hif1alpha, cMyc and Cyr61 as a function of postmortem interval. Our data suggest that the molecular quality of cutaneous tissue is well preserved for at least 60 min after death, which can be regarded as important information for consideration of the order for tissue procurement in in vivo studies and acute ex vivo dermal studies.
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Affiliation(s)
- Neera V Gopee
- Division of Biochemical Toxicology, and National Toxicology Program Center for Phototoxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Department of Health and Human Services, Jefferson, Arkansas 72079, USA
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355
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Waxman S, Wurmbach E. De-regulation of common housekeeping genes in hepatocellular carcinoma. BMC Genomics 2007; 8:243. [PMID: 17640361 PMCID: PMC1937003 DOI: 10.1186/1471-2164-8-243] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Accepted: 07/18/2007] [Indexed: 11/22/2022] Open
Abstract
Background Tumorigenesis is associated with changes in gene expression and involves many pathways. Dysregulated genes include "housekeeping" genes that are often used for normalization for quantitative real-time RT-PCR (qPCR), which may lead to unreliable results. This study assessed eight stages of hepatitis C virus (HCV) induced hepatocellular carcinoma (HCC) to search for appropriate genes for normalization. Results Gene expression profiles using microarrays revealed differential expression of most "housekeeping" genes during the course of HCV-HCC, including glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and beta-actin (ACTB), genes frequently used for normalization. QPCR reactions confirmed the regulation of these genes. Using them for normalization had strong effects on the extent of differential expressed genes, leading to misinterpretation of the results. Conclusion As shown here in the case of HCV-induced HCC, the most constantly expressed gene is the arginine/serine-rich splicing factor 4 (SFRS4). The utilization of at least two genes for normalization is robust and advantageous, because they can compensate for slight differences of their expression when not co-regulated. The combination of ribosomal protein large 41 (RPL41) and SFRS4 used for normalization led to very similar results as SFRS4 alone and is a very good choice for reference in this disease as shown on four differentially expressed genes.
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Affiliation(s)
- Samuel Waxman
- Mount Sinai School of Medicine, Department of Medicine, Division of Hematology/Oncology, New York, NY, USA
| | - Elisa Wurmbach
- Mount Sinai School of Medicine, Department of Medicine, Division of Hematology/Oncology, New York, NY, USA
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356
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Lassmann S, Shen Y, Jütting U, Wiehle P, Walch A, Gitsch G, Hasenburg A, Werner M. Predictive Value of Aurora-A/STK15 Expression for Late Stage Epithelial Ovarian Cancer Patients Treated by Adjuvant Chemotherapy. Clin Cancer Res 2007; 13:4083-91. [PMID: 17634533 DOI: 10.1158/1078-0432.ccr-06-2775] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE To investigate the expression and regulation of the centrosomal kinase Aurora-A/STK15 (AURKA) in epithelial ovarian cancers and to determine the prognostic and predictive value of this marker for patients with late stage epithelial ovarian cancer treated by distinct adjuvant chemotherapies. EXPERIMENTAL DESIGN Archival resection specimens of epithelial ovarian cancers (n=115) and nonneoplastic ovaries (n=28) were analyzed for AURKA mRNA and protein expression by microdissection and quantitative reverse transcriptase-PCR and immunohistochemistry. AURKA DNA copy numbers were measured by fluorescence in situ hybridization in 37 cases. Statistical evaluation was done with respect to clinicopathologic variables, disease-free survival, and overall survival. RESULTS AURKA mRNA expression was significantly elevated in cancers (P<0.001) and correlated with AURKA protein expression (P=0.0134). Overexpression of AURKA protein was detected in 68 of 107 (63.5%) cases and was linked with increased AURKA DNA copy numbers (P=0.0141) and centromere 20 aneusomy (P=0.0137). Moreover, AURKA overexpression was associated with improved overall survival in optimal debulked patients receiving taxol/carboplatin therapy (n=43, P=0.018). Finally, in an exploratory approach, patients receiving non-taxane-based therapy, AURKA overexpression was predictive for worse overall survival (n=30, P=0.049). CONCLUSIONS AURKA overexpression is seen in the majority of late stage epithelial ovarian cancers, most likely due to increased AURKA DNA copy numbers and/or chromosome 20 aneusomy. Importantly, AURKA overexpression may differentially affect taxane and non-taxane-based adjuvant therapy responses. The study sheds new light on AURKA expression and regulation in epithelial cancers in vivo and specifically shows its value as a clinically relevant marker and as a potential therapeutic target per se.
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Affiliation(s)
- Silke Lassmann
- Institute of Pathology, University Hospital, Albert-Ludwigs-University Freiburg, Freiburg, Germany.
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357
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Jung M, Ramankulov A, Roigas J, Johannsen M, Ringsdorf M, Kristiansen G, Jung K. In search of suitable reference genes for gene expression studies of human renal cell carcinoma by real-time PCR. BMC Mol Biol 2007; 8:47. [PMID: 17559644 PMCID: PMC1913536 DOI: 10.1186/1471-2199-8-47] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Accepted: 06/08/2007] [Indexed: 11/23/2022] Open
Abstract
Background Housekeeping genes are commonly used as endogenous reference genes for the relative quantification of target genes in gene expression studies. No conclusive systematic study comparing the suitability of different candidate reference genes in clear cell renal cell carcinoma has been published to date. To remedy this situation, 10 housekeeping genes for normalizing purposes of RT-PCR measurements already recommended in various studies were examined with regard to their usefulness as reference genes. Results The expression of the potential reference genes was examined in matched malignant and non-malignant tissue specimens from 25 patients with clear cell renal cell carcinoma. Quality assessment of isolated RNA performed with a 2100 Agilent Bioanalyzer showed a mean RNA integrity number of 8.7 for all samples. The between-run variations related to the crossing points of PCR reactions of a control material ranged from 0.17% to 0.38%. The expression of all genes did not depend on age, sex, and tumour stage. Except the genes TATA box binding protein (TBP) and peptidylprolyl isomerase A (PPIA), all genes showed significant differences in expression between malignant and non-malignant pairs. The expression stability of the candidate reference genes was additionally controlled using the software programs geNorm and NormFinder. TBP and PPIA were validated as suitable reference genes by normalizing the target gene ADAM9 using these two most stably expressed genes in comparison with up- and down-regulated housekeeping genes of the panel. Conclusion Our study demonstrated the suitability of the two housekeeping genes PPIA and TBP as endogenous reference genes when comparing malignant tissue samples with adjacent normal tissue samples from clear cell renal cell carcinoma. Both genes are recommended as reference genes for relative gene quantification in gene profiling studies either as single gene or preferably in combination.
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Affiliation(s)
- Monika Jung
- Department of Urology, Charité – Universitätsmedizin Berlin, Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany
| | - Azizbek Ramankulov
- Department of Urology, Charité – Universitätsmedizin Berlin, Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany
- Republic Center of Urology, Bishkek, Kyrgyz Republic
| | - Jan Roigas
- Department of Urology, Charité – Universitätsmedizin Berlin, Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany
| | - Manfred Johannsen
- Department of Urology, Charité – Universitätsmedizin Berlin, Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany
| | - Martin Ringsdorf
- Department of Urology, Charité – Universitätsmedizin Berlin, Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany
| | - Glen Kristiansen
- Institute of Pathology, Charité – Universitätsmedizin Berlin, Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany
| | - Klaus Jung
- Department of Urology, Charité – Universitätsmedizin Berlin, Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany
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358
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Baisden B, Sonne S, Joshi RM, Ganapathy V, Shekhawat PS. Antenatal dexamethasone treatment leads to changes in gene expression in a murine late placenta. Placenta 2007; 28:1082-90. [PMID: 17559929 PMCID: PMC2040329 DOI: 10.1016/j.placenta.2007.04.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Revised: 03/30/2007] [Accepted: 04/06/2007] [Indexed: 11/29/2022]
Abstract
Antenatal steroids like dexamethasone (DEX) are used to augment fetal lung maturity and there is a major concern that they impair fetal growth. If delivery is delayed after using antenatal DEX, placental function and hence fetal growth may be compromised even further. To investigate the effects of DEX on placental function, we treated 9 pregnant C57/BL6 mice with DEX and 9 pregnant mice were injected with saline to serve as controls. Placental gene expression was studied using microarrays in 3 pairs and other 6 pairs were used to confirm microarray results by semi-quantitative RT-PCR, real-time PCR, in situ hybridization, western blot analysis and Oligo ApopTaq assay. DEX-treated placentas were hydropic, friable, pale, and weighed less (80.0+/-15.1mg compared to 85.6.8+/-7.6mg, p=0.05) (n=62 placentas). Fetal weight was significantly reduced after DEX use (940+/-32mg compared to 1162+/-79mg, p=0.001) (n=62 fetuses). There was >99% similarity within and between the three gene chip data sets. DEX led to down-regulation of 1212 genes and up-regulation of 1382 genes. RT-PCR studies showed that DEX caused a decrease in expression of genes involved in cell division such as cyclins A2, B1, D2, cdk 2, cdk 4 and M-phase protein kinase along with growth-promoting genes such as EGF-R, BMP4 and IGFBP3. Oligo ApopTaq assay and western blot studies showed that DEX-treatment increased apoptosis of trophoblast cells. DEX-treatment led to up-regulation of aquaporin 5 and tryptophan hydroxylase genes as confirmed by real-time PCR, and in situ hybridization studies. Thus antenatal DEX treatment led to a reduction in placental and fetal weight, and this effect was associated with a decreased expression of several growth-promoting genes and increased apoptosis of trophoblast cells.
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Affiliation(s)
- B Baisden
- Department of Pediatrics, Medical College of Georgia, Augusta, GA 30912, USA
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359
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Deepak SA, Kottapalli KR, Rakwal R, Oros G, Rangappa KS, Iwahashi H, Masuo Y, Agrawal GK. Real-Time PCR: Revolutionizing Detection and Expression Analysis of Genes. Curr Genomics 2007; 8:234-51. [PMID: 18645596 PMCID: PMC2430684 DOI: 10.2174/138920207781386960] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2007] [Revised: 02/27/2007] [Accepted: 03/02/2007] [Indexed: 02/06/2023] Open
Abstract
Invention of polymerase chain reaction (PCR) technology by Kary Mullis in 1984 gave birth to real-time PCR. Real-time PCR - detection and expression analysis of gene(s) in real-time - has revolutionized the 21(st) century biological science due to its tremendous application in quantitative genotyping, genetic variation of inter and intra organisms, early diagnosis of disease, forensic, to name a few. We comprehensively review various aspects of real-time PCR, including technological refinement and application in all scientific fields ranging from medical to environmental issues, and to plant.
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Affiliation(s)
- SA Deepak
- Department of Studies in Applied Botany and Biotechnology, University of Mysore, Manasagangotri, Mysore 570006,
India
| | - KR Kottapalli
- Plant Genome Research Unit, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba 305-
8602, Ibaraki, Japan
| | - R Rakwal
- Human Stress Signal Research Center (HSS), National Institute of Advanced Industrial Science
and Technology (AIST), Tsukuba West, 16-1 Onogawa, Tsukuba 305-8569, Ibaraki, Japan
- Research Laboratory for
Agricultural Biotechnology and Biochemistry (RLABB), GPO Box 8207, Kathmandu, Nepal
| | - G Oros
- Plant Protection Institute,
Hungarian Academy of Sciences, Budapest, Hungary
| | - KS Rangappa
- Department of Studies in Chemistry, University of Mysore,
Manasagangotri, Mysore 570006, India
| | - H Iwahashi
- Human Stress Signal Research Center (HSS), National Institute of Advanced Industrial Science
and Technology (AIST), Tsukuba West, 16-1 Onogawa, Tsukuba 305-8569, Ibaraki, Japan
| | - Y Masuo
- Human Stress Signal Research Center (HSS), National Institute of Advanced Industrial Science
and Technology (AIST), Tsukuba West, 16-1 Onogawa, Tsukuba 305-8569, Ibaraki, Japan
| | - GK Agrawal
- Research Laboratory for
Agricultural Biotechnology and Biochemistry (RLABB), GPO Box 8207, Kathmandu, Nepal
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360
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Cai JH, Deng S, Kumpf SW, Lee PA, Zagouras P, Ryan A, Gallagher DS. Validation of rat reference genes for improved quantitative gene expression analysis using low density arrays. Biotechniques 2007; 42:503-12. [PMID: 17489238 DOI: 10.2144/000112400] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Real-time PCR has become increasingly important in gene expression profiling research, and it is widely agreed that normalized data are required for accurate estimates of messenger RNA (mRNA) expression. With increased gene expression profiling in pre-clinical research and toxicogenomics, a need for reference genes in the rat has emerged, and the studies in this area have not yet been thoroughly evaluated. The purpose of our study was to evaluate a panel of rat reference genes for variation of gene expression in different tissue types. We selected 48 known target genes based on their putative invariability. The gene expression of all targets was examined in 11 types of rat tissues using TaqMan® low density array (LDA) technology. The variability of each gene was assessed using a two-step statistical model. The analysis of mean expression using multiple reference genes was shown to provide accurate and reliable normalized expression data. The least five variable genes from each specific tissue were recommended for future tissue-specific studies. Finally, a subset of investigated rat reference genes showing the least variation is recommended for further evaluation using the LDA platform. Our work should considerably enhance a researcher's ability to simply and efficiently identify appropriate reference genes for given experiments.
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Affiliation(s)
- Jenny Hong Cai
- Pfizer Global Research and Development, Pfizer Inc., Groton, CT 06340, USA.
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361
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Røge R, Thorsen J, Tørring C, Ozbay A, Møller BK, Carstens J. Commonly used reference genes are actively regulated in in vitro stimulated lymphocytes. Scand J Immunol 2007; 65:202-9. [PMID: 17257226 DOI: 10.1111/j.1365-3083.2006.01879.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Quantitative polymerase chain reaction (Q-PCR) studies of urine sediments have demonstrated an increased expression of cytotoxin genes during episodes of acute rejection of renal allografts. To compensate for differences in initial sample size and cDNA preparation, standard Q-PCR experiments involve normalization to a reference gene. Although stable expression of reference genes is a prerequisite for any Q-PCR analysis, commonly used reference genes have demonstrated a varying expression across tissues and various stimuli. In this study, cellular expression of several reference genes was investigated in a mixed lymphocyte reaction as a model of gene expression during alloreactive T-lymphocyte activation and acute rejection. Gene expression was quantified using Q-PCR, normalized to cell counts obtained by DNA quantification and corrected for cell polyploidy using flow cytometry. Examined reference genes were 18S rRNA, beta-actin (ACTB), hydroxymethylbilane synthase (HMBS), hypoxanthine phosphoribosyltransferase (HPRT1) and peptidylprolyle isomerase B (PPIB). This study also examined two novel T-lymphocyte-specific reference genes: CD3E and CD8B. HMBS and HPRT were 18.8- and 7.4-fold upregulated, respectively, ACTB was 5.3-fold upregulated, PPIB was 3.2-fold upregulated while 18S rRNA remained stably expressed. The T-lymphocyte-specific reference gene CD3E remained stable while CD8B was upregulated 2.3-fold. In conclusion, several commonly used reference genes were actively regulated during alloreactive T-lymphocyte activation. Additionally, we introduce two stable T-lymphocyte-specific reference genes that might be useful in a Q-PCR analysis of T-lymphocyte-specific cytotoxin genes in urine sediments, as they overcome the contribution of reference gene mRNA from cells irrelevant for diagnosis.
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Affiliation(s)
- R Røge
- Research Laboratory C, Department of Nephrology, Skejby Hospital, Aarhus N, Denmark.
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362
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Synnergren J, Giesler TL, Adak S, Tandon R, Noaksson K, Lindahl A, Nilsson P, Nelson D, Olsson B, Englund MCO, Abbot S, Sartipy P. Differentiating human embryonic stem cells express a unique housekeeping gene signature. Stem Cells 2007; 25:473-80. [PMID: 17284652 DOI: 10.1634/stemcells.2006-0247] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Housekeeping genes (HKGs) are involved in basic functions needed for the sustenance of the cell and are assumed to be constitutively expressed at a constant level. Based on these features, HKGs are frequently used for normalization of gene expression data. In the present study, we used the CodeLink Gene Expression Bioarray system to interrogate changes in gene expression occurring during differentiation of human ESCs (hESCs). Notably, in the three hESC lines used for the study, we observed that the RNA levels of 56 frequently used HKGs varied to a degree that rendered them inappropriate as reference genes. Therefore, we defined a novel set of HKGs specifically for hESCs. Here we present a comprehensive list of 292 genes that are stably expressed (coefficient of variation <20%) in differentiating hESCs. These genes were further grouped into high-, medium-, and low-expressed genes. The expression patterns of these novel HKGs show very little overlap with results obtained from somatic cells and tissues. We further explored the stability of this novel set of HKGs in independent, publicly available gene expression data from hESCs and observed substantial similarities with our results. Gene expression was confirmed by real-time quantitative polymerase chain reaction analysis. Taken together, these results suggest that differentiating hESCs have a unique HKG signature and underscore the necessity to validate the expression profiles of putative HKGs. In addition, this novel set of HKGs can preferentially be used as controls in gene expression analyses of differentiating hESCs.
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Affiliation(s)
- Jane Synnergren
- School of Humanities and Informatics, University of Skövde, P.O. Box 408, SE-541 28 Skövde, Sweden.
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363
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Chen QR, Vansant G, Oades K, Pickering M, Wei JS, Song YK, Monforte J, Khan J. Diagnosis of the small round blue cell tumors using multiplex polymerase chain reaction. J Mol Diagn 2007; 9:80-8. [PMID: 17251339 PMCID: PMC1867426 DOI: 10.2353/jmoldx.2007.060111] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The small round blue cell tumors of childhood, which include neuroblastoma, rhabdomyosarcoma, non-Hodgkin's lymphoma, and the Ewing's family of tumors, are so called because of their similar appearance on routine histology. Using cDNA microarray gene expression profiles and artificial neural networks (ANNs), we previously identified 93 genes capable of diagnosing these cancers. Using a subset of these, together with some additional genes (total 39), we developed a multiplex polymerase chain reaction (PCR) assay to diagnose these cancer types. Blinded testing of 96 new samples (26 Ewing's family of tumors, 29 rhabdomyosarcomas, 24 neuroblastomas, and 17 lymphomas) using ANNs in a complete leave-one-out analysis demonstrated that all except one sample were accurately diagnosed as their respective category. Moreover, using an ANN-based gene minimization strategy in a separate analysis, we found that the top 31 genes could correctly diagnose all 96 tumors. Our results suggest that this molecular test based on a multiplex PCR reaction may assist the physician in the rapid confirmation of the diagnosis of these cancers.
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Affiliation(s)
- Qing-Rong Chen
- Oncogenomics Section, Pediatric Oncology Branch, Advanced Technology Center, National Cancer Institute, 8717 Grovemont Circle, Gaithersburg, MD 20877, USA
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364
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Lassmann S, Schuster I, Walch A, Göbel H, Jütting U, Makowiec F, Hopt U, Werner M. STAT3 mRNA and protein expression in colorectal cancer: effects on STAT3-inducible targets linked to cell survival and proliferation. J Clin Pathol 2007; 60:173-9. [PMID: 17264243 PMCID: PMC1860635 DOI: 10.1136/jcp.2005.035113] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS To evaluate mRNA and protein expression of signal transducers and activators of transcription (STAT)3 in colorectal carcinomas (CRCs) and to define the association of STAT3 activity with the STAT3-inducible targets cyclin D1, survivin, Bcl-xl and Mcl-1. MATERIALS AND METHODS Matching serial sections of normal colonic epithelium and invasive CRCs (n = 32) were subjected to quantitative reverse transcriptase polymerase chain reaction specific to STAT3, cyclin D1, survivin, Bcl-xl and Mcl-1, as well as immunohistochemistry. For STAT3 immunohistochemistry, two antibodies, recognising unphosphorylated (UP-) and phosphorylated (tyr705, P-) STAT3 were used. Ki-67 (MIB-1) staining was included as a proliferation marker. RESULTS Compared with normal colonic epithelium, UP-STAT3 and P-STAT3 (p = 0.023 and 0.006) protein expression and expression of its associated targets cyclin D1, survivin and Bcl-xl were significantly (all p<0.001) increased in carcinoma. In carcinomas, STAT3 (p = 0.019) and Bcl-xl (p = 0.001) mRNAs were correlated with lymph node status. Moreover, nuclear P-STAT3 protein expression (active state) was associated with the expression of its target genes Bcl-xl (p = 0.038) and survivin (p = 0.01) as well as with Ki-67 (p = 0.017). By contrast, cytoplasmic UP-STAT was significantly linked to Bcl-xl mRNA (p = 0.024) and protein (p = 0.001) as well as to cytoplasmic survivin protein expression (p = 0.019). CONCLUSION Both inactive (UP-STAT3) and active (P-STAT3) STAT3 proteins are markedly increased in invasive CRCs. This is associated with Bcl-xl and survivin induction, increased proliferation and lymph node metastasis. This study therefore provides the basis for further examination of the prognostic or predictive value of these molecular markers in CRC.
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Affiliation(s)
- Silke Lassmann
- Institut für Parthologie, Universitätsklinikum Freiburg, Freiburg, Germany.
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365
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Lazarus JE, Hegde A, Andrade AC, Nilsson O, Baron J. Fibroblast growth factor expression in the postnatal growth plate. Bone 2007; 40:577-86. [PMID: 17169623 DOI: 10.1016/j.bone.2006.10.013] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2006] [Revised: 10/07/2006] [Accepted: 10/23/2006] [Indexed: 01/08/2023]
Abstract
Fibroblast growth factor (FGF) signaling is essential for endochondral bone formation. Mutations cause skeletal dysplasias including achondroplasia, the most common human skeletal dysplasia. Most previous work in this area has focused on embryonic chondrogenesis. To explore the role of FGF signaling in the postnatal growth plate, we quantitated expression of FGFs and FGF receptors (FGFRs) and examined both their spatial and temporal regulation. Toward this aim, rat proximal tibial growth plates and surrounding tissues were microdissected, and specific mRNAs were quantitated by real-time RT-PCR. To assess the FGF system without bias, we first screened for expression of all known FGFs and major FGFR isoforms. Perichondrium expressed FGFs 1, 2, 6, 7, 9, and 18 and, at lower levels, FGFs 21 and 22. Growth plate expressed FGFs 2, 7, 18, and 22. Perichondrial expression was generally greater than growth plate expression, supporting the concept that perichondrial FGFs regulate growth plate chondrogenesis. Nevertheless, FGFs synthesized by growth plate chondrocytes may be physiologically important because of their proximity to target receptors. In growth plate, we found expression of FGFRs 1, 2, and 3, primarily, but not exclusively, the c isoforms. FGFRs 1 and 3, thought to negatively regulate chondrogenesis, were expressed at greater levels and at later stages of chondrocyte differentiation, with FGFR1 upregulated in the hypertrophic zone and FGFR3 upregulated in both proliferative and hypertrophic zones. In contrast, FGFRs 2 and 4, putative positive regulators, were expressed at earlier stages of differentiation, with FGFR2 upregulated in the resting zone and FGFR4 in the resting and proliferative zones. FGFRL1, a presumed decoy receptor, was expressed in the resting zone. With increasing age and decreasing growth velocity, FGFR2 and 4 expression was downregulated in proliferative zone. Perichondrial FGF1, FGF7, FGF18, and FGF22 were upregulated. In summary, we have analyzed the expression of all known FGFs and FGFRs in the postnatal growth plate using a method that is quantitative and highly sensitive. This approach identified ligands and receptors not previously known to be expressed in growth plate and revealed a complex pattern of spatial regulation of FGFs and FGFRs in the different zones of the growth plate. We also found temporal changes in FGF and FGFR expression which may contribute to growth plate senescence and thus help determine the size of the adult skeleton.
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Affiliation(s)
- Jacob E Lazarus
- Developmental Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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366
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Bertolotto A, Sala A, Caldano M, Capobianco M, Malucchi S, Marnetto F, Gilli F. Development and validation of a real time PCR-based bioassay for quantification of neutralizing antibodies against human interferon-beta. J Immunol Methods 2007; 321:19-31. [PMID: 17335844 DOI: 10.1016/j.jim.2006.12.012] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Revised: 11/20/2006] [Accepted: 12/20/2006] [Indexed: 11/29/2022]
Abstract
There are two commonly employed types of bioassays for the detection of neutralizing antibodies (NAbs) against interferon-beta (IFNbeta): the cytopatic effect assay (CPE), and the MxA (myxovirus resistance protein A) protein assay (MPA). This article describes a bioassay based on the real time PCR measurement of mRNA that results from the induction, in cultured human cells, of the MxA gene by IFNbeta. Serum samples from 104 patients with multiple sclerosis (MS) treated with IFNbeta were tested for NAbs using our real time PCR bioassay. NAbs also were measured in the same specimens by the MPA assay and CPE assay. The calibration range of the real time PCR bioassay is 0.125-30 LU/mL. The range of the intra- and inter-assay variations (coefficients of variation in log(10)) were 4.05% (range 0.88%-7.90%) and 4.42% (range 0.31%-9.15%), respectively. Samples of the three commercial preparations of IFNbeta-1a and -1b were measured showing dose-response curves parallel to that of the NIH reference IFNbeta (mean SD at the midpoint of the dose-response curve=5%). In addition, the assay was robust with respect to number of cells plated (i.e., increasing cell densities from 12x10(3)/well to 384x10(3)/well resulted in 3.03% variability in MxA expression normalized with glyceraldehyde-3 phosphate dehydrogenase). NAbs titers measured were closely comparable to those obtained by the MPA [r(spearman)=0.899; 89% of observed agreements; K=0.779] and the CPE [r(spearman)=0.7899); 86%; K=0.729] assays. Despite the obvious disadvantage of cost, when carried out according to quality assurance guidelines for molecular diagnostics the new MxA gene-expression assay (MGA) has significant advantages over the other methods for testing NAbs: it has excellent reliability and reproducibility, and utilizes equipment and methodologies already accessible in many clinical laboratories.
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Affiliation(s)
- A Bertolotto
- Centro Riferimento Regionale Sclerosi Multipla (CRESM) & Neurobiologia Clinica, Ospedale Universitario S. Luigi Gonzaga, Regione Gonzole 10, I-10043, Orbassano, Torino, Italy.
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367
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Filby AL, Tyler CR. Appropriate 'housekeeping' genes for use in expression profiling the effects of environmental estrogens in fish. BMC Mol Biol 2007; 8:10. [PMID: 17288598 PMCID: PMC1802086 DOI: 10.1186/1471-2199-8-10] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2006] [Accepted: 02/08/2007] [Indexed: 11/25/2022] Open
Abstract
Background Attempts to develop a mechanistic understanding of the effects of environmental estrogens on fish are increasingly conducted at the level of gene expression. Appropriate application of real-time PCR in such studies requires the use of a stably expressed 'housekeeping' gene as an internal control to normalize for differences in the amount of starting template between samples. Results We sought to identify appropriate genes for use as internal controls in experimental treatments with estrogen by analyzing the expression of eight functionally distinct 'housekeeping' genes (18S ribosomal RNA [18S rRNA], ribosomal protein l8 [rpl8], elongation factor 1 alpha [ef1a], glucose-6-phosphate dehydrogenase [g6pd], beta actin [bactin], glyceraldehyde-3-phosphate dehydrogenase [gapdh], hypoxanthine phosphoribosyltransferase 1 [hprt1], and tata box binding protein [tbp]) following exposure to the environmental estrogen, 17α-ethinylestradiol (EE2), in the fathead minnow (Pimephales promelas). Exposure to 10 ng/L EE2 for 21 days down-regulated the expression of ef1a, g6pd, bactin and gapdh in the liver, and bactin and gapdh in the gonad. Some of these effects were gender-specific, with bactin in the liver and gapdh in the gonad down-regulated by EE2 in males only. Furthermore, when ef1a, g6pd, bactin or gapdh were used for normalization, the hepatic expression of two genes of interest, vitellogenin (vtg) and cytochrome P450 1A (cyp1a) following exposure to EE2 was overestimated. Conclusion Based on the data presented, we recommend 18S rRNA, rpl8, hprt1 and/or tbp, but not ef1a, g6pd, bactin and/or gapdh, as likely appropriate internal controls in real-time PCR studies of estrogens effects in fish. Our studies show that pre-validation of control genes considering the scope and nature of the experiments to be performed, including both gender and tissue type, is critical for accurate assessments of the effects of environmental estrogens on gene expression in fish.
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Affiliation(s)
- Amy L Filby
- Environmental and Molecular Fish Biology Group, School of Biosciences, Hatherly Laboratories, University of Exeter, Prince of Wales Road, Exeter, Devon, EX4 4PS, UK
| | - Charles R Tyler
- Environmental and Molecular Fish Biology Group, School of Biosciences, Hatherly Laboratories, University of Exeter, Prince of Wales Road, Exeter, Devon, EX4 4PS, UK
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368
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Sugiura SH, Kelsey K, Ferraris RP. Molecular and conventional responses of large rainbow trout to dietary phosphorus restriction. J Comp Physiol B 2007; 177:461-72. [PMID: 17279387 DOI: 10.1007/s00360-007-0144-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2006] [Revised: 12/15/2006] [Accepted: 01/03/2007] [Indexed: 11/29/2022]
Abstract
The dietary phosphorus (P) requirement for large fish is difficult to estimate because of insensitivities of known P status indicators. We examined dietary P requirement of large rainbow trout (mean body weight 278 g) using recently identified P-responsive genes (mRNA abundances) as well as conventional serum P and bone P. Fish were fed six diets (varied P contents), and the tissues of intestine, pyloric caeca (PC), kidney, serum and bone were collected at varying time intervals. Serum P responded clearly to dietary P by day 2, but the estimated P requirement based on this variable changed as feeding duration continued. Bone P did not respond clearly until week 7. Among P-responsive genes studied, Na/Pi cotransporter in PC (PC-NaPi) was the most sensitive, and responded in 2 days. Fish-to-fish (within treatment) variance was larger in mRNA than in serum P and bone P levels. Estimated dietary P requirements (%P in dry diet) were 0.45 (based on serum P), 0.45 (based on bone P), 0.36 (based on PC-NaPi), 0.33 (based on intestinal NaPi), 0.71 (based on renal NaPi), and 0.33 (based on mitochondrial Pi carrier). This study is the first to evaluate the potential of genomic approaches in determining nutrient requirements of fish.
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Affiliation(s)
- Shozo H Sugiura
- Department of Pharmacology & Physiology, New Jersey Medical School, University of Medicine & Dentistry of New Jersey, Newark, NJ 07103, USA.
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369
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Schultz IJ, Wester K, Straatman H, Kiemeney LA, Babjuk M, Mares J, Willems JL, Swinkels DW, Witjes JA, Malmström PU, de Kok JB. Gene Expression Analysis for the Prediction of Recurrence in Patients with Primary Ta Urothelial Cell Carcinoma. Eur Urol 2007; 51:416-22; discussion 422-3. [PMID: 16920253 DOI: 10.1016/j.eururo.2006.07.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Accepted: 07/19/2006] [Indexed: 11/18/2022]
Abstract
OBJECTIVES The individual recurrence-free period after primary surgery of patients with Ta urothelial cell carcinoma (UCC) cannot be predicted accurately. This study aims at discriminating between patients with primary Ta UCC and long or short recurrence-free periods. METHODS We investigated mRNA expression of 23 genes in 44 primary Ta tumours (23 and 21 tumours were from patients with long [>or=4 yr] or short [<or=2 yr] recurrence-free periods, respectively), using real-time quantitative polymerase chain reaction. The genes were selected from previously published studies and showed a relationship with tumour recurrence in patients with UCC. RESULTS Differential mRNA expression between the two patient groups indicated statistical significance only for the gene survivin (p=0.0011). Its recurrence predictive value could not be increased by a combination with any of the other genes. Comparison of the receiver operating characteristic curves for survivin expression between patients with long or short recurrence-free intervals revealed an area under the curve of 0.79 (95%CI, 0.65-0.92). Using the median expression (0.84) as cut-off level, survivin identified 71.4% (95%CI, 47.8-88.7) and 69.6% (95%CI, 47.1-86.8) of the patients with long or short recurrence-free periods, respectively. CONCLUSIONS Our study identifies survivin as the most promising candidate to distinguish between patients with primary Ta UCC and long or short recurrence-free intervals. Therefore, survivin mRNA expression analysis might help the urologist to individualise patient treatment and prevent unnecessary cystoscopies in a subgroup of these patients.
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Affiliation(s)
- Iman J Schultz
- Department of Clinical Chemistry, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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370
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Gozgit JM, Pentecost BT, Marconi SA, Otis CN, Wu C, Arcaro KF. Use of an aggressive MCF-7 cell line variant, TMX2-28, to study cell invasion in breast cancer. Mol Cancer Res 2007; 4:905-13. [PMID: 17189381 DOI: 10.1158/1541-7786.mcr-06-0147] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
An estrogen receptor-negative variant of the MCF-7 breast cancer cell line, TMX2-28, was used as a model in which to study breast cancer cell invasion. Using a reconstituted basement membrane (Matrigel) assay to evaluate cell invasion, we determined that TMX2-28 cells are more invasive than MCF-7 cells and that the invasiveness of TMX2-28 is similar to that of the aggressive MDA-MB-231 breast cancer cell line. TMX2-28 cells displayed a rounded, epithelial cell-like morphology, suggesting an amoeboid mode of cell invasion, in contrast to the mesenchymal mode of invasion characteristic of spindle-shaped, fibroblast-like MDA-MB-231 cells. Using real-time reverse transcription-PCR, we found that mitogen-inducible gene 2 (MIG2) is expressed at a 17-fold higher level in TMX2-28 cells than in nonaggressive MCF-7 cells and that MIG2 mRNA levels are low in the nontumorigenic human mammary epithelial cell line, 184. We determined that MIG2 plays a role in cell invasion by using small interfering RNA (siRNA) to suppress the expression of MIG2 mRNA levels in TMX2-28 cells. TMX2-28 cell invasion was reduced by 48% when the cells were transfected with siRNAs targeting MIG2, relative to cells transfected with siRNAs against glyceraldehyde-3-phosphate dehydrogenase. Finally, MIG2 expression was evaluated in reductive mammoplasty and breast tumor tissue. Although all 21 normal tissues from reduction mammoplasty showed immunoreactivity for MIG2, ranging from weak (62%) to strong (24%), only half of the 34 formalin-fixed breast tumors showed immunoreactivity for MIG2. Of these 17 positive cases, 10 were considered to overexpress MIG2 (moderate to strong staining). Examination of 30 frozen breast tumors supported the finding that MIG2 is overexpressed in a subset of breast cancers. We suggest that MIG2's normal regulation and function are disrupted in breast cancer.
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Affiliation(s)
- Joseph M Gozgit
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts, USA
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371
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Nishimura M, Koeda A, Suzuki E, Kawano Y, Nakayama M, Satoh T, Narimatsu S, Naito S. Regulation of mRNA expression of MDR1, MRP1, MRP2 and MRP3 by prototypical microsomal enzyme inducers in primary cultures of human and rat hepatocytes. Drug Metab Pharmacokinet 2007; 21:297-307. [PMID: 16946557 DOI: 10.2133/dmpk.21.297] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The mRNA induction of various transporters by rifampicin (Rif), dexamethasone (Dex) and omeprazole (Ome) was investigated in primary cultures of cryopreserved human and rat hepatocytes. Analysis was performed by quantitative real-time RT-PCR using primers and TaqMan probes. In primary cultures of human hepatocytes, mRNA levels of MDR and MRP1 were increased by about 1.5 fold and 1.3 fold, respectively, by exposure to Rif at 2 to 50 microM as compared with 0.1% DMSO-treated controls. MRP2 mRNA levels in the same human hepatocytes were significantly increased by 1.2 to 1.8 fold by exposure to Rif at 50 microM as compared with controls. In primary cultures of rat hepatocytes, Mdr1a and Mdr1b mRNA levels were not increased or only slightly increased at 24 hr by exposure to any of the inducers at 2, 10 or 50 microM. Mrp2 mRNA levels in the same rat hepatocytes were significantly increased by 7 to 45 fold by exposure to Dex at 2 microM as compared with controls. Based on the species differences observed in the present study, primary cultures of cryopreserved hepatocytes from both the human and rat should be useful in preclinical drug development for evaluating candidate drugs for transporter induction.
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Affiliation(s)
- Masuhiro Nishimura
- Department of Drug Metabolism, Division of Pharmacology, Drug Safety and Metabolism, Otsuka Pharmaceutical Factory Inc., Naruto, Tokushima, Japan.
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372
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Abstract
We report the results of an optical assay to determine the degree of cell wall disruption in yeast. The results indicate that cell wall disruption with glass beads yields reproducible results that can be modelled with an integral measure of time to failure that implies a decreasing failure rate. It is shown that a standard protocol results in only 60% disruption, with a relatively large coefficient of variation. The data show that the yield of total RNA harvested is proportional to the degree of cellular disruption, and that there is no loss of RNA quality with > 90% disruption. The data also show that cell disruption of a synchronous culture varies with the cell cycle. We speculate that the decreasing failure rate is related to the cell cycle phase-dependent disruptability.
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Affiliation(s)
- Chris C Stowers
- Department of Chemical Engineering, Vanderbilt University, Nashville, TN 37232, USA
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373
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Sugiura SH, Roy PK, Ferraris RP. Dietary acidification enhances phosphorus digestibility but decreases H+/K+-ATPase expression in rainbow trout. ACTA ACUST UNITED AC 2006; 209:3719-28. [PMID: 16985189 DOI: 10.1242/jeb.02436] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Oxynticopeptic cells of fish stomach are thought to secrete less acid than the specialized parietal cells of mammalian stomach. Gastric acidity, however, has not been directly compared between fish and mammals. We therefore fed rainbow trout and rats the same meal, and found that the lowest postprandial pH of trout stomach was 2.7, which was only transiently sustained for 1 h, whereas that of rat stomach was 1.3, which was sustained for 3 h. Postprandial pH of the small intestine was slightly higher in trout (approximately 8.0) than in rats (approximately 7.6), but pH of the large intestine was similar (approximately 8.0). Addition of acids to fish feeds, in an attempt to aid the weak acidity of fish stomach, has been known to improve phosphorus digestibility, but its physiological effect on fish stomach is not known. Exogenous acids did improve phosphorus digestibility but also decreased steady-state mRNA expression of trout H(+)/K(+)-ATPase (ATP4A, the proton pump) as well as Na(+)/bicarbonate cotransporter (NBC), and had no effect on gastrin-like mRNA and somastostatin (SST) mRNA abundance. Gastrin-like mRNA and SST-2 mRNA were equally distributed between corpus and antrum. ATP4A mRNA and NBC mRNA were in the corpus, whereas SST-1 mRNA was in the antrum. Trout gastrin-like EST had modest homology to halibut and pufferfish gastrin, whereas trout ATP4A mRNA had > or = 95% amino acid homology with mammalian, Xenopus and flounder ATP4A. Although ATP4A seems highly conserved among vertebrates, gastric acidity is much less in trout than in rats, explaining the low digestibility of bone phosphorus, abundant in fish diets. Dietary acidification does not reduce acidity enough to markedly improve phosphorus digestibility, perhaps because exogenous acids may inhibit endogenous acid production.
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Affiliation(s)
- Shozo H Sugiura
- Department of Pharmacology and Physiology, UMDNJ-New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA
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374
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Stålberg P, Santesson M, Ekeblad S, Lejonklou MH, Skogseid B. Recognizing genes differentially regulated in vitro by the multiple endocrine neoplasia type 1 (MEN1) gene, using RNA interference and oligonucleotide microarrays. Surgery 2006; 140:921-9; discussion 929-31. [PMID: 17188139 DOI: 10.1016/j.surg.2006.06.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2006] [Accepted: 06/30/2006] [Indexed: 10/24/2022]
Abstract
BACKGROUND Data on downstream effects of MEN1 gene inactivation is scarce. In an effort to identify genes regulated by MEN1, we designed a silencing experiment in a human endocrine pancreatic tumor cell line (BON1). METHODS By using RNA interference, MEN1 mRNA expression was knocked-down by >85%. Gene expression was assessed by oligonucleotide microarrays and compared to expression in nonsilenced controls. We also investigated if genes were differentially expressed in 6 malignant endocrine pancreatic tumors (EPTs) with homozygous MEN1 inactivation compared to 2 without MEN1 gene alterations. RESULTS Using a cut-off of > or =2 times, 66 genes were found to be upregulated, and 22 were downregulated in the MEN1-silenced clones. We corroborated the microarray findings by performing quantitative-PCR on the RNA from the silencing experiments for 7 of the 88 differentially regulated genes. Genes involved in endocrine cell fate determination, as well as genes known to be involved in NFkappaB, Notch, and Wnt signaling pathways, were among genes verified as differentially regulated in vitro. CONCLUSIONS The demonstration of pathways affected by silencing of MEN1 in vitro provides novel insight into neoplastic processes of potential importance in vivo, which warrants further study.
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MESH Headings
- Cell Line, Tumor
- DNA, Neoplasm/genetics
- Gene Expression Profiling
- Gene Expression Regulation, Neoplastic/physiology
- Genes, Neoplasm/genetics
- Genes, Neoplasm/physiology
- Humans
- NF-kappa B/genetics
- NF-kappa B/metabolism
- Oligonucleotide Array Sequence Analysis
- Pancreatic Neoplasms/genetics
- Pancreatic Neoplasms/metabolism
- Pancreatic Neoplasms/pathology
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- RNA Interference
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Neoplasm/genetics
- Receptors, Notch/genetics
- Receptors, Notch/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Transfection
- Wnt Proteins/genetics
- Wnt Proteins/metabolism
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Affiliation(s)
- Peter Stålberg
- Department of Surgical Sciences, University Hospital, Uppsala, Sweden
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375
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O'Grady EP, Mulcahy H, O'Callaghan J, Adams C, O'Gara F. Pseudomonas aeruginosa infection of airway epithelial cells modulates expression of Kruppel-like factors 2 and 6 via RsmA-mediated regulation of type III exoenzymes S and Y. Infect Immun 2006; 74:5893-902. [PMID: 16988269 PMCID: PMC1594899 DOI: 10.1128/iai.00489-06] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Pseudomonas aeruginosa is an important opportunistic pathogen which is capable of causing both acute and chronic infections in immunocompromised patients. Successful adaptation of the bacterium to its host environment relies on the ability of the organism to tightly regulate gene expression. RsmA, a small RNA-binding protein, controls the expression of a large number of virulence-related genes in P. aeruginosa, including those encoding the type III secretion system and associated effector proteins, with important consequences for epithelial cell morphology and cytotoxicity. In order to examine the influence of RsmA-regulated functions in the pathogen on gene expression in the host, we compared global expression profiles of airway epithelial cells in response to infection with P. aeruginosa PAO1 and an rsmA mutant. The RsmA-dependent response of host cells was characterized by significant changes in the global transcriptional pattern, including the increased expression of two Kruppel-like factors, KLF2 and KLF6. This increased expression was mediated by specific type III effector proteins. ExoS was required for the enhanced expression of KLF2, whereas both ExoS and ExoY were required for the enhanced expression of KLF6. Neither ExoT nor ExoU influenced the expression of the transcription factors. Additionally, the increased gene expression of KLF2 and KLF6 was associated with ExoS-mediated cytotoxicity. Therefore, this study identifies for the first time the human transcription factors KLF2 and KLF6 as targets of the P. aeruginosa type III exoenzymes S and Y, with potential importance in host cell death.
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Affiliation(s)
- Eoin P O'Grady
- BIOMERIT Research Centre, Department of Microbiology, University College Cork, Cork, Ireland
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376
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Reid KE, Olsson N, Schlosser J, Peng F, Lund ST. An optimized grapevine RNA isolation procedure and statistical determination of reference genes for real-time RT-PCR during berry development. BMC PLANT BIOLOGY 2006; 6:27. [PMID: 17105665 PMCID: PMC1654153 DOI: 10.1186/1471-2229-6-27] [Citation(s) in RCA: 570] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2006] [Accepted: 11/14/2006] [Indexed: 05/12/2023]
Abstract
BACKGROUND Accuracy in quantitative real-time RT-PCR is dependent on high quality RNA, consistent cDNA synthesis, and validated stable reference genes for data normalization. Reference genes used for normalization impact the results generated from expression studies and, hence, should be evaluated prior to use across samples and treatments. Few statistically validated reference genes have been reported in grapevine. Moreover, success in isolating high quality RNA from grapevine tissues is typically limiting due to low pH, and high polyphenolic and polysaccharide contents. RESULTS We describe optimization of an RNA isolation procedure that compensates for the low pH found in grape berries and improves the ability of the RNA to precipitate. This procedure was tested on pericarp and seed developmental series, as well as steady-state leaf, root, and flower tissues. Additionally, the expression stability of actin, AP47 (clathrin-associated protein), cyclophilin, EF1-alpha (elongation factor 1-alpha), GAPDH (glyceraldehyde 3-phosphate dehydrogenase), MDH (malate dehydrogenase), PP2A (protein phosphatase), SAND, TIP41, alpha-tubulin, beta-tubulin, UBC (ubiquitin conjugating enzyme), UBQ-L40 (ubiquitin L40) and UBQ10 (polyubiquitin) were evaluated on Vitis vinifera cv. Cabernet Sauvignon pericarp using three different statistical approaches. Although several of the genes proved to be relatively stable, no single gene outperformed all other genes in each of the three evaluation methods tested. Furthermore, the effect of using one reference gene versus normalizing to the geometric mean of several genes is presented for the expression of an aquaporin and a sucrose transporter over a developmental series. CONCLUSION In order to quantify relative transcript abundances accurately using real-time RT-PCR, we recommend that combinations of several genes be used for normalization in grape berry development studies. Our data support GAPDH, actin, EF1-alpha and SAND as the most relevant reference genes for this purpose.
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Affiliation(s)
- Karen E Reid
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, Canada
| | - Niclas Olsson
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, Canada
| | - James Schlosser
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, Canada
| | - Fred Peng
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, Canada
| | - Steven T Lund
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, Canada
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377
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Kooter IM, Pennings JLA, Fokkens PHB, Leseman DLAC, Boere AJF, Gerlofs-Nijland ME, Cassee FR, Schalk JAC, Orzechowski TJH, Schaap MM, Breit TM, Dormans JAMA, van Oostrom CTM, de Vries A, van Steeg H. Ozone induces clear cellular and molecular responses in the mouse lung independently of the transcription-coupled repair status. J Appl Physiol (1985) 2006; 102:1185-92. [PMID: 17095637 DOI: 10.1152/japplphysiol.00796.2006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The oxidant ozone is a well-known air pollutant, inhalation of which is associated with respiratory tract inflammation and functional alterations of the lung. It is well established as an inducer of intracellular oxidative stress. We investigated whether Cockayne syndrome B, transcription-coupled, repair-deficient mice (Csb(-/-)), known to be sensitive to oxidative stressors, respond differently to ozone than repair-proficient controls (Csb(+/-)). Mice were exposed to 0.8 parts/million ozone for 8 h, and we examined a wide range of biological parameters in the lung at the gene expression, protein, and cellular level 4 h after the ozone exposure. Relevant biological responses to ozone for both repair-deficient Csb(-/-) and repair-proficient Csb(+/-) mice, as determined by biochemical analysis of bronchoalveolar lavage fluid (e.g., increases of polymorphonuclear neutrophils, alkaline phosphatase, macrophage-inflammatory protein-2, and tumor necrosis factor-alpha), pathological examinations, and gene expression (upregulation of oxidative-stress-related genes) analyses were observed. The bronchoalveolar lavage fluid showed significantly more tumor necrosis factor-alpha in repair-deficient Csb(-/-) mice than in repair-proficient Csb(+/-) mice after ozone exposure. In addition, a clear trend was observed toward fewer differentially expressed genes with a lower fold ratio in repair-deficient Csb(-/-) mice than in repair-proficient Csb(+/-) mice. However, repair-deficient Csb(-/-) mice do not respond significantly more sensitively to ozone compared with repair-proficient Csb(+/-) mice at the level of gene expression. We conclude that, under the conditions employed here, although small differences at the transcriptional level exist between repair-proficient Csb(+/-) mice and transcription-coupled repair defective Csb(-/-) mice, these do not have a significant effect on the ozone-induced lung injury.
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Affiliation(s)
- Ingeborg M Kooter
- National Institute for Public Health and the Environment, Bilthoven, the Netherlands.
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378
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Zhang Z, Hu J. Development and validation of endogenous reference genes for expression profiling of medaka (Oryzias latipes) exposed to endocrine disrupting chemicals by quantitative real-time RT-PCR. Toxicol Sci 2006; 95:356-68. [PMID: 17093204 DOI: 10.1093/toxsci/kfl161] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The quantitative real-time reverse transcription polymerase chain reaction (Q-RT-PCR) technique has been increasingly used in endocrine disrupting chemicals (EDCs) research. Usually, an appropriate endogenous control gene is critical for Q-RT-PCR to normalize the errors and sample-to-sample variations that occur in the course of tissue collection, RNA isolation, and RT-PCR. In this study, we cloned ribosomal protein L7 (RPL-7) from medaka (Oryzias latipes), and then used Q-RT-PCR to study its transcription characteristics and those of glyceraldehyde-3-phosphate dehydrogenase, beta-actin, mitochondrial 16S ribosomal RNA (16S rRNA), and 18S rRNA. Of the five genes, RPL-7 and 18S rRNA were expressed with the less variance among the same tissue samples, in different tissues, and stages of development and were unaffected by EDCs exposure. The expression levels of RPL-7 among different tissues were between 9.76 x 10(6) +/- 9.49 x 10(5) and 1.39 x 10(7) +/- 1.69 x 10(6) copies/microg RNA but those of 18S rRNA were as high as 4.48 x 10(11) +/- 5.95 x 10(10) to 5.90 x 10(11) +/- 1.21 x 10(10) copies/microg RNA, which is above the usual detection scope of Q-RT-PCR if no complementary DNA reaction dilution is performed. As a result, RPL-7 is the single suitable endogenous control gene for expression profiling in future studies, especially in studies on the EDCs issue using medaka.
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Affiliation(s)
- Zhaobin Zhang
- College of Environmental Science, Peking University, Beijing 100871, China
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379
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Baumbusch LO, Myhre S, Langerød A, Bergamaschi A, Geisler SB, Lønning PE, Deppert W, Dornreiter I, Børresen-Dale AL. Expression of full-length p53 and its isoform Deltap53 in breast carcinomas in relation to mutation status and clinical parameters. Mol Cancer 2006; 5:47. [PMID: 17054774 PMCID: PMC1636663 DOI: 10.1186/1476-4598-5-47] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2006] [Accepted: 10/20/2006] [Indexed: 11/22/2022] Open
Abstract
Background The tumor suppressor gene p53 (TP53) controls numerous signaling pathways and is frequently mutated in human cancers. Novel p53 isoforms suggest alternative splicing as a regulatory feature of p53 activity. Results In this study we have analyzed mRNA expression of both wild-type and mutated p53 and its respective Δp53 isoform in 88 tumor samples from breast cancer in relation to clinical parameters and molecular subgroups. Three-dimensional structure differences for the novel internally deleted p53 isoform Δp53 have been predicted. We confirmed the expression of Δp53 mRNA in tumors using quantitative real-time PCR technique. The mRNA expression levels of the two isoforms were strongly correlated in both wild-type and p53-mutated tumors, with the level of the Δp53 isoform being approximately 1/3 of that of the full-length p53 mRNA. Patients expressing mutated full-length p53 and non-mutated (wild-type) Δp53, "mutational hybrids", showed a slightly higher frequency of patients with distant metastasis at time of diagnosis compared to other patients with p53 mutations, but otherwise did not differ significantly in any other clinical parameter. Interestingly, the p53 wild-type tumors showed a wide range of mRNA expression of both p53 isoforms. Tumors with mRNA expression levels in the upper or lower quartile were significantly associated with grade and molecular subtypes. In tumors with missense or in frame mutations the mRNA expression levels of both isoforms were significantly elevated, and in tumors with nonsense, frame shift or splice mutations the mRNA levels were significantly reduced compared to those expressing wild-type p53. Conclusion Expression of p53 is accompanied by the functionally different isoform Δp53 at the mRNA level in cell lines and human breast tumors. Investigations of "mutational hybrid" patients highlighted that wild-type Δp53 does not compensates for mutated p53, but rather may be associated with a worse prognosis. In tumors, both isoforms show strong correlations in different mutation-dependent mRNA expression patterns.
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Affiliation(s)
- Lars O Baumbusch
- Department of Genetics, Institute for Cancer Research, Rikshospitalet-Radiumhospitalet Medical Center, 0310 Oslo, Norway
| | - Simen Myhre
- Department of Genetics, Institute for Cancer Research, Rikshospitalet-Radiumhospitalet Medical Center, 0310 Oslo, Norway
| | - Anita Langerød
- Department of Genetics, Institute for Cancer Research, Rikshospitalet-Radiumhospitalet Medical Center, 0310 Oslo, Norway
| | - Anna Bergamaschi
- Department of Genetics, Institute for Cancer Research, Rikshospitalet-Radiumhospitalet Medical Center, 0310 Oslo, Norway
- Medical Faculty, University of Oslo, Oslo, Norway
| | - Stephanie B Geisler
- Department of Medicine, Section of Oncology, Haukeland University Hospital, 5021 Bergen, Norway
| | - Per E Lønning
- Department of Medicine, Section of Oncology, Haukeland University Hospital, 5021 Bergen, Norway
| | - Wolfgang Deppert
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie an der Universität Hamburg, Martinistr. 52, 20251 Hamburg, Germany
| | - Irene Dornreiter
- Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie an der Universität Hamburg, Martinistr. 52, 20251 Hamburg, Germany
| | - Anne-Lise Børresen-Dale
- Department of Genetics, Institute for Cancer Research, Rikshospitalet-Radiumhospitalet Medical Center, 0310 Oslo, Norway
- Medical Faculty, University of Oslo, Oslo, Norway
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380
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Schultz IJ, Wester K, Straatman H, Kiemeney LA, Babjuk M, Mares J, Willems JL, Swinkels DW, Witjes JA, de Kok JB, Malmström PU. Prediction of recurrence in Ta urothelial cell carcinoma by real-time quantitative PCR analysis: a microarray validation study. Int J Cancer 2006; 119:1915-9. [PMID: 16721812 DOI: 10.1002/ijc.22059] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Accurate prediction of tumor recurrence in patients with superficial urothelial cell carcinoma (UCC) might result in a significant reduction of invasive follow-up cystoscopies. A recent study identified a panel of 26 genes from a large cDNA microarray analysis of bladder tumors that discriminated between early- and late-recurring patients with superficial Ta tumors (Dyrskjøt et al., Nat Genet 2003;33:90-6). We aimed to validate this panel of genes in 44 primary Ta UCCs (23 and 21 tumors from patients with short or prolonged recurrence-free periods, respectively), by real-time quantitative PCR. Statistical analysis showed marginal significant different mRNA expression levels between the 2 patient groups. To evaluate a supplementary effect of genes for the identification of patients with short or prolonged recurrence-free intervals, forward logistic regression analysis was applied. This revealed that a combination of the expression profiles of the genes HNRPK, LTB4DH and ANP32B resulted in the best performance, although the combination only marginally increased the predictive value of HNRPK alone. Comparing the receiver-operating-characteristic curves for HNRPK expression among patients with short or prolonged recurrence-free periods, revealed an area under the curve of 0.696 (95% CI, 0.537-0.855). Using the median HNRPK expression level as cut-off, a sensitivity of 69.6% and a specificity of 71.4% were obtained for the identification of patients with short or prolonged recurrence-free periods, respectively. In conclusion, we were not able to confirm the microarray gene expression pattern of the 26 genes shown by Dyrskjøt et al. The discovery of accurate recurrence predictive markers, therefore, remains a challenge.
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Affiliation(s)
- Iman J Schultz
- Department of Clinical Chemistry, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
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381
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Schmidt U, Fuessel S, Koch R, Baretton GB, Lohse A, Tomasetti S, Unversucht S, Froehner M, Wirth MP, Meye A. Quantitative multi-gene expression profiling of primary prostate cancer. Prostate 2006; 66:1521-34. [PMID: 16921506 DOI: 10.1002/pros.20490] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND This study describes the evaluation of the expression patterns of prostate-related transcripts in 106 matched prostate tissues from prostatectomies as predictors for prostate cancer (PCa). METHODS Quantitative PCR (QPCR) assays with site-specific hybridization probes were established for four housekeeping genes (GAPDH, HPRT, PBGD, TBP) and nine prostate-related genes (AibZIP, D-GPCR, EZH2, PCA3, PDEF, prostein, PSA, PSCA, TRPM8). RESULTS The relative mRNA expression levels of AibZIP, D-GPCR, EZH2, PCA3, PDEF, PSA, TRPM8 (all P < 0.001) and prostein (P = 0.019) normalized to the TBP reference gene were significantly higher in malignant compared to non-malignant prostate tissues. Employing receiver-operating characteristic (ROC) analyses, PCA3 was the best single tumor marker with the highest area-under-the-curve (AUC = 0.85). A multivariate logit model for the predictability of the tumor was developed, which employed the relative expression levels of EZH2, PCA3, prostein, and TRPM8 and yielded an AUC of 0.90. CONCLUSIONS The transcript marker PCA3 is a powerful predictor of primary PCa but the inclusion of EZH2, prostein, and TRPM8 adds even more to the diagnostic power. The finding of a significantly higher mRNA expression of three different genes (prostein, PSA, TRPM8) in organ-confined tumors compared to non-organ-confined tumors as well as the multi-marker PCa prediction model developed in the retrospective model system on prostatectomies could be of clinical importance for diagnostic purposes, and should be verified in diagnostic biopsies.
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Affiliation(s)
- Uta Schmidt
- Department of Urology, Technical University of Dresden, Germany
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382
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Christov CP, Gardiner TJ, Szüts D, Krude T. Functional requirement of noncoding Y RNAs for human chromosomal DNA replication. Mol Cell Biol 2006; 26:6993-7004. [PMID: 16943439 PMCID: PMC1592862 DOI: 10.1128/mcb.01060-06] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Noncoding RNAs are recognized increasingly as important regulators of fundamental biological processes, such as gene expression and development, in eukaryotes. We report here the identification and functional characterization of the small noncoding human Y RNAs (hY RNAs) as novel factors for chromosomal DNA replication in a human cell-free system. In addition to protein fractions, hY RNAs are essential for the establishment of active chromosomal DNA replication forks in template nuclei isolated from late-G(1)-phase human cells. Specific degradation of hY RNAs leads to the inhibition of semiconservative DNA replication in late-G(1)-phase template nuclei. This inhibition is negated by resupplementation of hY RNAs. All four hY RNAs (hY1, hY3, hY4, and hY5) can functionally substitute for each other in this system. Mutagenesis of hY1 RNA showed that the binding site for Ro60 protein, which is required for Ro RNP assembly, is not essential for DNA replication. Degradation of hY1 RNA in asynchronously proliferating HeLa cells by RNA interference reduced the percentages of cells incorporating bromodeoxyuridine in vivo. These experiments implicate a functional role for hY RNAs in human chromosomal DNA replication.
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Affiliation(s)
- Christo P Christov
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, United Kingdom
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383
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Fülöp P, Derdák Z, Sheets A, Sabo E, Berthiaume EP, Resnick MB, Wands JR, Paragh G, Baffy G. Lack of UCP2 reduces Fas-mediated liver injury in ob/ob mice and reveals importance of cell-specific UCP2 expression. Hepatology 2006; 44:592-601. [PMID: 16941708 DOI: 10.1002/hep.21310] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Fatty liver is vulnerable to conditions that challenge hepatocellular energy homeostasis. Lipid-laden hepatocytes highly express uncoupling protein-2 (UCP2), a mitochondrial carrier that competes with adenosine triphosphate (ATP) synthesis by mediating proton leak. However, evidence for a link between UCP2 expression and susceptibility of liver to acute injury is lacking. We asked whether absence of UCP2 protects ob/ob mice from Fas-mediated acute liver damage. UCP2-deficient ob/ob mice (ob/ob:ucp2-/-) and UCP2-competent littermates (ob/ob:ucp2+/+) received a single dose of agonistic anti-Fas antibody (Jo2). Low-dose Jo2 (0.15 mg/kg intraperitoneally) caused less serum alanine aminotransferase (ALT) elevation and lower apoptosis rates in ob/ob:ucp2-/- mice. High-dose Jo2 (0.40 mg/kg intraperitoneally) proved uniformly fatal; however, ob/ob:ucp2-/- mice survived longer with less depletion of liver ATP stores, indicating that fatty hepatocytes may benefit from lack of UCP2 during Jo2 challenge. Although UCP2 reportedly controls mitochondrial oxidant production, its absence had no apparent effect on fatty liver tissue malondialdehyde levels augmented by Jo2. This finding prompted us to determine UCP2 expression in Kupffer cells, a major source of intrahepatic oxidative stress. UCP2 expression was found diminished in Kupffer cells of untreated ob/ob:ucp2+/+ mice, conceivably contributing to increased oxidative stress in fatty liver and limiting the impact of UCP2 ablation. In conclusion, whereas UCP2 abundance in fatty hepatocytes exacerbates Fas-mediated injury by compromising ATP stores, downregulation of UCP2 in Kupffer cells may account for persistent oxidative stress in fatty liver. Our data support a cell-specific approach when considering the therapeutic effects of mitochondrial uncoupling in fatty liver disease.
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Affiliation(s)
- Péter Fülöp
- Division of Gastroenterology & Liver Research Center, Brown Medical School and Rhode Island Hospital, Providence, Rhode Island 02903, USA
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384
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Klamp T, Sahin U, Kyewski B, Schwendemann J, Dhaene K, Türeci O. Expression profiling of autoimmune regulator AIRE mRNA in a comprehensive set of human normal and neoplastic tissues. Immunol Lett 2006; 106:172-9. [PMID: 16876259 DOI: 10.1016/j.imlet.2006.06.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2006] [Revised: 06/13/2006] [Accepted: 06/15/2006] [Indexed: 01/17/2023]
Abstract
Defects in the autoimmune regulator (AIRE) gene cause the monogenic autoimmune disease autoimmune polyendocrinopathy syndrome type 1 (APS-1), which is characterized by a loss of self-tolerance to multiple organs. In concordance with its role in immune tolerance, AIRE is strongly expressed in medullary thymic epithelial cells (mTECs). Data on mechanisms controlling AIRE activation and the expression of this gene in other tissues are fragmentary and controversial. We report here AIRE mRNA expression profiling of a large set of normal human tissues and cells, tumor specimen and methylation deficient cell lines. On this broad data basis we found that AIRE mRNA expression is confined to mTECs in thymus and to lymph node tissue and that DNA hypomethylation contributes to transcriptional control of this gene.
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MESH Headings
- Cell Line, Tumor
- DNA Methylation
- Gene Expression Profiling/methods
- Gene Expression Regulation, Neoplastic
- Humans
- Immune Tolerance/genetics
- Lymph Nodes/immunology
- Lymph Nodes/metabolism
- Lymph Nodes/pathology
- Neoplasms/genetics
- Neoplasms/immunology
- Neoplasms/metabolism
- Neoplasms/pathology
- Polyendocrinopathies, Autoimmune/genetics
- Polyendocrinopathies, Autoimmune/immunology
- Polyendocrinopathies, Autoimmune/metabolism
- Polyendocrinopathies, Autoimmune/pathology
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- RNA, Messenger/immunology
- Reverse Transcriptase Polymerase Chain Reaction
- Thymus Gland/immunology
- Thymus Gland/metabolism
- Thymus Gland/pathology
- Transcription Factors/biosynthesis
- Transcription Factors/immunology
- Transcription, Genetic/immunology
- AIRE Protein
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Affiliation(s)
- Thorsten Klamp
- Department of Internal Medicine III, Johannes-Gutenberg University Mainz, Obere Zahlbacherstr 63, 55131 Mainz, Germany
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385
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Jongstra-Bilen J, Haidari M, Zhu SN, Chen M, Guha D, Cybulsky MI. Low-grade chronic inflammation in regions of the normal mouse arterial intima predisposed to atherosclerosis. ACTA ACUST UNITED AC 2006; 203:2073-83. [PMID: 16894012 PMCID: PMC2118407 DOI: 10.1084/jem.20060245] [Citation(s) in RCA: 256] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Atherosclerotic lesions develop in regions of arterial curvature and branch points, which are exposed to disturbed blood flow and have unique gene expression patterns. The cellular and molecular basis for atherosclerosis susceptibility in these regions is not completely understood. In the intima of atherosclerosis-predisposed regions of the wild-type C57BL/6 mouse aorta, we quantified increased expression of several proinflammatory genes that have been implicated in atherogenesis, including vascular cell adhesion molecule–1 (VCAM-1) and a relative abundance of dendritic cells, but only occasional T cells. In contrast, very few intimal leukocytes were detected in regions resistant to atherosclerosis; however, abundant macrophages, including T cells, were found throughout the adventitia (Adv). Considerably lower numbers of intimal CD68+ leukocytes were found in inbred atherosclerosis-resistant C3H and BALB/c mouse strains relative to C57BL/6 and 129; however, leukocyte distribution throughout the Adv of all strains was similar. The predominant mechanism for the accumulation of intimal CD68+ cells was continued recruitment of bone marrow–derived blood monocytes, suggestive of low-grade chronic inflammation. Local proliferation of intimal leukocytes was low. Intimal CD68+ leukocytes were reduced in VCAM-1–deficient mice, suggesting that mechanisms of leukocyte accumulation in the intima of normal aorta are analogous to those in atherosclerosis.
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Affiliation(s)
- Jenny Jongstra-Bilen
- Toronto General Research Institute, University Health Network, Toronto, Ontario M5G 2C4, Canada
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386
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Nishimura M, Koeda A, Suzuki E, Shimizu T, Kawano Y, Nakayama M, Satoh T, Narimatsu S, Naito S. Effects of prototypical drug-metabolizing enzyme inducers on mRNA expression of housekeeping genes in primary cultures of human and rat hepatocytes. Biochem Biophys Res Commun 2006; 346:1033-9. [PMID: 16777070 DOI: 10.1016/j.bbrc.2006.06.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2006] [Accepted: 06/02/2006] [Indexed: 11/29/2022]
Abstract
Quantitative real-time RT-PCR was used to investigate the effects of prototypical drug-metabolizing enzyme inducers rifampicin (Rif), dexamethasone (Dex), and omeprazole (Ome) on mRNA expression levels of the housekeeping genes beta-actin (ACTB), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), beta-glucuronidase (GUSB), hypoxanthine phosphoribosyltransferase 1 (HPRT1), peptidylprolylisomerase A (PPIA), TATA box binding protein (TBP), and transferrin receptor (TFRC) in primary cultures of cryopreserved human and rat hepatocytes. The mRNA levels of ACTB, GAPDH, GUSB, PPIA, TBP, and TFRC relative to HPRT1 in human hepatocytes were constant at all concentrations of inducers. However, the mRNA level of GAPDH relative to HPRT1 in rat hepatocytes was markedly increased by Rif. The mRNA levels of GAPDH, GUSB, PPIA, TBP, and TFRC relative to HPRT1 in rat hepatocytes were significantly increased by Dex. ACTB and HPRT1 are suitable internal controls for evaluating mRNA expression levels in primary cultures of human and rat hepatocytes after Rif, Dex, or Ome exposure.
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Affiliation(s)
- Masuhiro Nishimura
- Department of Drug Metabolism, Division of Pharmacology, Drug Safety and Metabolism, Otsuka Pharmaceutical Factory, Inc., Naruto, Tokushima 772-8601, Japan.
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387
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Span PN, Tjan-Heijnen VCG, Heuvel JJTM, de Kok JB, Foekens JA, Sweep FCGJ. Do the survivin (BIRC5) splice variants modulate or add to the prognostic value of total survivin in breast cancer? Clin Chem 2006; 52:1693-700. [PMID: 16873289 DOI: 10.1373/clinchem.2006.071613] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND A total of 4 additional splice variants (survivin-DeltaEx3, survivin 2alpha, survivin-2B, and survivin-3B) have been described for survivin [baculoviral IAP repeat-containing protein (BIRC-5), approved gene symbol BIRC5], which has been implicated in both inhibition of apoptosis and regulation in mitosis in many tumor types. In this study, we assessed whether the survivin splice variants modulate or add to the prognostic value of total survivin in breast cancer. METHODS With quantitative reverse transcription-PCR, we measured mRNA concentrations of survivin and all variants in tumor tissue from 275 patients with breast cancer and associated these with clinicopathologic characteristics and relapse-free survival. RESULTS Total survivin, survivin-DeltaEx3, and survivin 2alpha mRNA levels were associated with young age and ductal histology. Total survivin and survivin-DeltaEx3 were highest in samples with advanced histological grade, whereas patients with 4-9 involved lymph nodes expressed less survivin-2B mRNA than those with 1-3 involved nodes. All variants were higher in tumors negative for steroid hormone receptors. Total survivin, survivin 2alpha, and survivin-3B were associated with poor relapse-free survival in univariate analyses. Survivin 2alpha and survivin-3B added to the prognostic value of total survivin in multivariate analyses. In addition, the prognostic value of total survivin was evident only in the presence of higher expression levels of these 2 variants. CONCLUSIONS All variants of survivin exhibited particular associations with clinicopathologic characteristics (age, histology, grade, and steroid hormone receptor status) of breast cancer patients. Survival analyses suggest a modulating role of survivin 2alpha and survivin-3B on the biological function of total survivin.
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Affiliation(s)
- Paul N Span
- Department of Chemical Endocrinology, RAdboud University of Nimegen Medical Centre, Nijmegen, The Netherlands.
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388
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Nordgård O, Kvaløy JT, Farmen RK, Heikkilä R. Error propagation in relative real-time reverse transcription polymerase chain reaction quantification models: the balance between accuracy and precision. Anal Biochem 2006; 356:182-93. [PMID: 16899212 DOI: 10.1016/j.ab.2006.06.020] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2006] [Revised: 05/18/2006] [Accepted: 06/15/2006] [Indexed: 11/18/2022]
Abstract
Real-time reverse transcription polymerase chain reaction (RT-PCR) has gained wide popularity as a sensitive and reliable technique for mRNA quantification. The development of new mathematical models for such quantifications has generally paid little attention to the aspect of error propagation. In this study we evaluate, both theoretically and experimentally, several recent models for relative real-time RT-PCR quantification of mRNA with respect to random error accumulation. We present error propagation expressions for the most common quantification models and discuss the influence of the various components on the total random error. Normalization against a calibrator sample to improve comparability between different runs is shown to increase the overall random error in our system. On the other hand, normalization against multiple reference genes, introduced to improve accuracy, does not increase error propagation compared to normalization against a single reference gene. Finally, we present evidence that sample-specific amplification efficiencies determined from individual amplification curves primarily increase the random error of real-time RT-PCR quantifications and should be avoided. Our data emphasize that the gain of accuracy associated with new quantification models should be validated against the corresponding loss of precision.
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Affiliation(s)
- Oddmund Nordgård
- Department of Hematology and Oncology, Stavanger University Hospital, 4068 Stavanger, Norway.
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389
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Steinau M, Rajeevan MS, Unger ER. DNA and RNA references for qRT-PCR assays in exfoliated cervical cells. J Mol Diagn 2006; 8:113-8. [PMID: 16436642 PMCID: PMC1867570 DOI: 10.2353/jmoldx.2006.050088] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The noncritical use of housekeeping genes, RNA mass, or cell number for normalization in quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) assays has come under scrutiny in recent years, highlighting the need to evaluate references in the immediate context of the relevant samples and experimental design. The purpose of this study was to select appropriate references for normalizing qRT-PCR assays of gene expression in exfoliated cervical cells. We used total nucleic acid extracts from 30 samples, representing the full spectrum of pre-invasive cervical neoplasia. We determined the DNA content by quantitative PCR for the single-copy gene beta-globin and total RNA content using quantitative image analysis of ribosomal bands. In addition, qRT-PCR for 13 candidate housekeeping genes was performed. We used two analysis methods, geNorm and Norm-Finder, to identify the best combination of reference genes and then correlated housekeeping gene expression with DNA content and gel representation of ribosomal RNA. ACTB was the most stable single gene. The addition of PGK1 and RPLP0 increased the robustness in qRT-PCR applications not stratified by disease. These genes also showed the highest correlation with DNA contents in the same samples. If special attention to intraepithelial lesions is appropriate, RPL4 and PGK1 are recommended as the best combination of two genes.
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Affiliation(s)
- Martin Steinau
- Human Papillomavirus Program, Centers for Disease Control and Prevention, 1600 Clifton Rd., MS G41, Atlanta, GA 30333, USA
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390
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Dréau D, Karaa A, Culberson C, Wyan H, McKillop IH, Clemens MG. Bosentan® inhibits tumor vascularization and bone metastasis in an immunocompetent skin-fold chamber model of breast carcinoma cell metastasis. Clin Exp Metastasis 2006; 23:41-53. [PMID: 16826430 DOI: 10.1007/s10585-006-9016-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2005] [Accepted: 04/27/2006] [Indexed: 11/26/2022]
Abstract
Angiogenic factors including endothelin-1 (ET-1) play a key role in the progression of breast metastases to bone. We investigated the impact of ET-1 on the development of bone metastases in an immunocompetent murine skin-fold chamber model. Murine mammary carcinoma 4T1 was injected in a skin-fold chamber implanted on CB6 mice along with bone explants. Furthermore, mice were treated with or without a dual selective antagonist of both ET-1 receptors. The progression of the vascularization within the chamber was monitored over time by intravital microscopy (IVM). The tumor growth and the development of bone metastases were assessed by cytokeratin-19 gene expression and histological studies. Results indicate that this new model associated with IVM allows for the continuous monitoring of the change in vascularization associated with the development of bone metastases. Additionally, treatment with an antagonist of both ET-1 receptors was associated with the presence of significantly less vessels near the tumor mass compared to control mice. These changes were correlated with smaller tumor masses and reduced bone invasion (P < 0.05). Thus, in an immunocompetent murine model of breast carcinoma metastases to bone, our data support the hypothesis that vascularization plays a role in tumor development and progression and that ET-1 specifically modulates the angiogenesis associated with breast metastases to the bone.
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Affiliation(s)
- Didier Dréau
- Department of Biology, University of North Carolina at Charlotte, Science & Technology Bldg, Rm. 490B, 9201 University City Blvd, Charlotte, NC 28223, USA.
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391
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Douard R, Moutereau S, Pernet P, Chimingqi M, Allory Y, Manivet P, Conti M, Vaubourdolle M, Cugnenc PH, Loric S. Sonic Hedgehog-dependent proliferation in a series of patients with colorectal cancer. Surgery 2006; 139:665-70. [PMID: 16701100 DOI: 10.1016/j.surg.2005.10.012] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Revised: 09/29/2005] [Accepted: 10/21/2005] [Indexed: 12/21/2022]
Abstract
BACKGROUND The Hedgehog (Hh) gene family is known to regulate development of stem cells. In addition, activation is responsible for the induction of GLI1 proto-oncogene and subsequent cellular proliferation. Sonic Hedgehog (SHh), one of the Hh family members promotes carcinogenesis in airway and pancreatic epithelia, is expressed in colonic stem cells. As differentiated colonic cells arise from constant renewal of Hedgehog-expressing colonic stem cells, SHh could be involved in human colonic carcinogenesis. METHODS Tissue samples of colorectal adenocarcinoma (T) and adjacent normal colon tissue (NT) were sampled from each of 44 consecutive patients with colorectal cancer. Specific transcription of SHh, GLI1, and the GLI1 downstream target FOXM1 were evaluated using semiquantitative reverse transcriptase polymerase chain reaction. Similar in vitro measurements of mRNA of GLI1 and FOXM1 transcription levels after specific induction by SHh-Np were performed in the HT-29 colorectal tumor cell line to confirm the in vivo results. RESULTS SHh mRNA was overexpressed in colorectal adenocarcinomas in 38 of 44 (86%) patients. Expression of transcription levels of GLI1 and FOXM1 correlated with SHh expression (SHh vs GLI1, r = 0.77, P < .0001; GLI1 vs FOXM1, r = 0.68, P < .0001; SHh vs FOXM1, r = 0.79, P < .0001). SHh overexpression did not appear to correlate with the patient characteristics evaluated. Similarly, when studied in the HT-29 colorectal cell line, exogenous SHh promoted cell proliferation, while inhibition of SHh expression decreased proliferation. Expression of GLI1 and FOXM1 mRNA increased with exogenous exposure to SHh. CONCLUSIONS We demonstrated increased expression of SHh mRNA in human colonic adenocarcinomas and in a colorectal cell line with downstream increased expression of GLI1 and FOXM1 mRNA known to promote cell proliferation. This upregulation within human colorectal adenocarcinoma tissue confirms the potential role of the Hh pathway in colorectal carcinogenesis and suggests a potential therapeutic target of Hh blockade in colorectal cancer.
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Affiliation(s)
- Richard Douard
- General Surgery Department, APHP Georges Pompidou University Hospital, Paris.
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392
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Xie W, Shao N, Ma X, Ling B, Wei Y, Ding Q, Yang G, Liu N, Wang H, Chen K. Bacterial endotoxin lipopolysaccharide induces up-regulation of glyceraldehyde-3-phosphate dehydrogenase in rat liver and lungs. Life Sci 2006; 79:1820-7. [PMID: 16843500 DOI: 10.1016/j.lfs.2006.06.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Revised: 05/16/2006] [Accepted: 06/10/2006] [Indexed: 11/29/2022]
Abstract
Bacterial endotoxin or lipopolysaccharide (LPS) can trigger inflammatory responses and cause damage in organs such as liver and lungs when it is introduced into mammals, but the exact molecular events that mediate these responses have remained obscure. In this study, by using 2D gel electrophoresis and cDNA microarray analysis, we found that both protein and mRNA levels of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were significantly increased in rat liver and lungs after treatment with LPS. The results were further confirmed by Western blot and Northern blot. Given the known role of GAPDH in inducing apoptosis, our results suggest that LPS-induced GAPDH up-regulation may be an important mechanism responsible for the damage induced by Gram negative bacteria in mammalian tissue and GAPDH may be involved in the signaling pathway of LPS induced apoptosis. Our results also demonstrate that GAPDH is not a suitable internal control in gene expression studies, especially when bacterial infection is involved.
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Affiliation(s)
- Wenguang Xie
- Affiliated Hospital, North Sichuan Medical College, Nanchong, China.
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393
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Sindelka R, Ferjentsik Z, Jonák J. Developmental expression profiles of Xenopus laevis reference genes. Dev Dyn 2006; 235:754-8. [PMID: 16397894 DOI: 10.1002/dvdy.20665] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cell differentiation depends mainly on specific mRNA expression. To quantify the expression of a particular gene, the normalisation with respect to the expression of a reference gene is carried out. This is based on the assumption that the expression of the reference gene is constant during development, in different cells or tissues or after treatment. Xenopus laevis studies have frequently used eEF-1 alpha, GAPDH, ODC, L8, and H4 as reference genes. The aim of this work was to examine, by real-time RT-PCR, the expression profiles of the above-mentioned five reference genes during early development of X. laevis. It is shown that their expression profiles vary greatly during X. laevis development. The developmental changes of mRNA expression can thus significantly compromise the relative mRNA quantification based on these reference genes, when different developmental stages are to be compared. The normalisation against total RNA is recommended instead.
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Affiliation(s)
- Radek Sindelka
- Department of Gene Expression, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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394
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Schultz IJ, Witjes JA, Swinkels DW, de Kok JB. Bladder cancer diagnosis and recurrence prognosis: Comparison of markers with emphasis on survivin. Clin Chim Acta 2006; 368:20-32. [PMID: 16480698 DOI: 10.1016/j.cca.2005.12.036] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2005] [Revised: 12/21/2005] [Accepted: 12/22/2005] [Indexed: 11/21/2022]
Abstract
Expression of the anti-apoptotic protein survivin is hardly detectable or even absent in many differentiated adult tissues, but is upregulated in almost any type of cancer. Furthermore, high survivin mRNA or protein expression generally correlates with an adverse disease course. Both these important features of survivin expression have been investigated for diagnostic and prognostic purposes in many human cancers, including bladder cancer. In this review, the role of survivin in the detection of bladder tumors and the prediction of tumor recurrence in patients with superficial bladder cancer will be discussed and compared to that of other markers/tests. The most promising marker(s) will be outlined. Also, important requirements for a successful implementation of such markers in a hospital setting are discussed. Finally, future directions for the discovery of new diagnostic or prognostic candidate markers will be mentioned.
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Affiliation(s)
- Iman J Schultz
- Department of Clinical Chemistry, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
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395
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Wolff RA, Malinowski RL, Heaton NS, Hullett DA, Hoch JR. Transforming growth factor-beta1 antisense treatment of rat vein grafts reduces the accumulation of collagen and increases the accumulation of h-caldesmon. J Vasc Surg 2006; 43:1028-36. [PMID: 16678700 DOI: 10.1016/j.jvs.2006.01.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Accepted: 01/20/2006] [Indexed: 10/24/2022]
Abstract
BACKGROUND The main cause of occlusion and vein graft failure after peripheral and coronary arterial reconstruction is intimal hyperplasia. Transforming growth factor beta-1 (TGF-beta1) is a pleiotropic cytokine known to have powerful effects on cell growth, apoptosis, cell differentiation, and extracellular matrix synthesis. METHODS To investigate the role of TGF-beta1 in intimal hyperplasia, we used adenovirus to deliver to superficial epigastric vein messenger RNA (mRNA) antisense to TGF-beta1 (Ad-AST) or the sequence encoding the bioactive form of TGF-beta1 (Ad-BAT). Infection with "empty" virus was used as a control (Ad-CMVpLpA). The treated vein was then used for an interposition graft into rat femoral artery. Grafts were harvested at 1, 2, 4, and 12 weeks and formalin-fixed for histologic studies or placed in liquid nitrogen for mRNA studies. RESULTS Ad-AST treatment resulted in an overall reduction of TGF-beta1 expression (P = .001), and Ad-BAT treatment resulted in an overall increase in TGF-beta1 expression (P = .007). Histologic analysis showed Ad-AST caused reduced collagen build up in the neointima at 12 weeks (P = .0001). Immunohistochemical staining for h-caldesmon at 12 weeks indicated Ad-AST increased smooth muscle cells throughout the vessel wall compared with Ad-CMVpLpA (P = .0024) or Ad-BAT (P = .04). Ad-AST also resulted in reduced CD68-positive cells in the media/adventitia (P = .005 vs Ad-CMVpLpA, P = .01 vs Ad-BAT). To further understand how Ad-AST was influencing the build up of collagen, we performed quantitative polymerase chain reaction on complimentary DNA (cDNA) from homogenates of the vein grafts. Tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) was increased at 1 week by Ad-BAT (P = .048 vs Ad-CMVpLpA) and decreased by Ad-AST at all time points (P </= .038). The mRNA for collagen-1 alpha-1 was decreased by Ad-AST at 2, 4, and 12 weeks (P < or = .05) and increased by Ad-BAT at 1 week (P = .01). CONCLUSIONS TGF-beta1 antisense treatment of vein grafts prevents the accumulation of collagen in the neointima in part by (1) changing the proportions of the cell types populating the vein graft wall, (2) reducing the mRNA for TIMPs, and (3) reducing the amount of collagen mRNA. With the Ad-AST and Ad-BAT treatments, we have been able to tip the maturation of the vein graft toward positive remodeling (artery-like phenotype) or toward negative remodeling (fibroproliferation and stenosis), respectively.
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Affiliation(s)
- Randal A Wolff
- William S. Middleton Memorial Veterans Hospital and University of Wisconsin Medical School, Madison, Wisconsin 53792-3236, USA.
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396
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Zhou S, Liu Y, Bo H, Bian X, Xia X, Lin C, Wong VWS, Lu Z. Expression profilings of 39 genes selected by ANOVA could separate precursors of murine dendritic cells and macrophages. Biochem Biophys Res Commun 2006; 344:438-45. [PMID: 16603127 DOI: 10.1016/j.bbrc.2006.03.125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2006] [Accepted: 03/06/2006] [Indexed: 11/29/2022]
Abstract
Dendritic cells (DCs) and macrophages share some stages in the development and function of antigen presentation. But it is difficult to separate them from their precursors. We used one-way ANOVA (analysis of variances) on murine expression profilings of several hematopoietic cells associated with DCs and macrophages to find the genes with great differences across the cell groups. These groups were the DCs from spleen, cultivated DCs, DC precursors, DC progenitors, DC progenitor cell lines, hematopoietic stem cell (HSC), and bone marrow-derived macrophages. The data of expression profilings were all downloaded from GEO and ArrayExpress database. After the normalization of 11 housekeeping genes across 42 arrays, we got 39 genes (44 probesets) by analysis of one-way ANOVA (Bonferroni step-down) with p values cutoff of 0.05. These genes (probesets) could separate the hematopoietic cells well by the methods of unsupervised hierarchical clustering and principal component analysis (PCA). The class prediction also indicated that these genes could separate the precursors of DC and macrophages with 20 arrays composed of 5 cell types with the same normalization. The accuracy rate of class prediction was 90% (18/20). The genes selected by one-way ANOVA included those of MHC (major histocompatibility complex) and defense of immunity, cell adhesion, chemokine or its receptors, and transcription factors. The results indicated that these 39 genes could separate precursors of DC and macrophages very clearly. It was suggested that these genes might represent some important molecules that related with the precursors of DCs and macrophages, and were worthy for further study.
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Affiliation(s)
- Shixin Zhou
- Chien-Shiung Wu Laboratory, Department of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
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397
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Bernat JA, Crawford GE, Ogurtsov AY, Collins FS, Ginsburg D, Kondrashov AS. Distant conserved sequences flanking endothelial-specific promoters contain tissue-specific DNase-hypersensitive sites and over-represented motifs. Hum Mol Genet 2006; 15:2098-105. [PMID: 16723375 DOI: 10.1093/hmg/ddl133] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The transcriptional regulation of genes is a complex process, particularly for genes exhibiting a tissue-specific pattern of expression. We studied 28 genes that are expressed primarily in endothelial cells, another 28 genes that are expressed highly, but not exclusively, in cultured endothelial cells, and three control sets, consisting of genes not expressed in endothelium, genes expressed in neural tissues and housekeeping genes. For each gene, we identified conserved non-coding sequences (CNSs) of lengths 50 to >1000 nucleotides, located within the upstream intergenic region (from 500 to as far as 200 000 nucleotides upstream from the transcription start) or within the first intron. As a functional test, we assayed the CNSs from the set of endothelial cell-specific genes (EC-CNSs) for DNase hypersensitivity. Among 262 distant EC-CNSs, 33% are hypersensitive (HS) in endothelial cells, whereas only 16% are HS in control fibroblasts. A search for short sequence patterns revealed a number of motifs which are over-represented in EC-CNSs relative to CNSs from the control gene sets. In particular, the motif SAGGAAR is strongly and consistently over-represented among EC-CNSs, and is more over-represented in HS CNSs than in non-HS CNSs. CNSs which contain this motif are no closer to the promoter than an average CNS. This motif contains the core element of binding sites from the Ets family of transcription factors. Thus, one or several factors from this family may play a key role in the regulation of endothelial gene expression.
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Affiliation(s)
- John A Bernat
- Department of Human Genetics, Howard Hughes Medical Institute, USA
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398
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Areda T, Raud S, Philips MA, Innos J, Matsui T, Kõks S, Vasar E, Karis A, Asser T. Cat odour exposure decreases exploratory activity and alters neuropeptide gene expression in CCK2 receptor deficient mice, but not in their wild-type littermates. Behav Brain Res 2006; 169:212-9. [PMID: 16488027 DOI: 10.1016/j.bbr.2006.01.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Revised: 01/03/2006] [Accepted: 01/12/2006] [Indexed: 10/25/2022]
Abstract
An attempt was made to establish whether the anxiogenic effect of cat odour differs in female wild-type and CCK(2) receptor deficient mice, having different exploratory activity in the elevated plus-maze. The exposure of wild-type and homozygous CCK(2) receptor deficient mice to cat odour did not reveal substantial differences between the two genotypes. The number of contacts with the cat odour impregnated cloth was reduced and the frequency of stretch-attend postures was increased similarly in wild-type and homozygous mice. However, the following exposure of mice to the elevated plus-maze established differences as homozygous mice displayed increased exploratory activity in the plus-maze. The cat odour exposure significantly reduced exploratory activity only in homozygous mice. Together with the increased exploratory activity we established in homozygous mice significantly increased expression of the Oprm1 gene in the frontal cortex and mesencephalon. The exposure of mice to cat odour caused only minor changes in the gene expression of wild-type mice, whereas in homozygous animals a significantly increased expression of the Mc3r gene in the frontal cortex and temporal lobe, and the Pomc1 gene in the temporal lobe, mesencephalon and mesolimbic area was established. In conclusion, CCK(2) receptor deficient mice displayed reduced anxiety compared to their wild-type littermates in the plus-maze test. This behavioural effect seems to be related, at least partly, to an increased tone of opioid system in the brain. Moreover, homozygous mice respond to the exposure of cat odour with an increased anxiety. This effect seems to be related to the increased function of the melanocortin system in the brain structures of genetically modified mice.
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Affiliation(s)
- Tarmo Areda
- Department of Physiology, University of Tartu, Estonia
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399
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Dydensborg AB, Herring E, Auclair J, Tremblay E, Beaulieu JF. Normalizing genes for quantitative RT-PCR in differentiating human intestinal epithelial cells and adenocarcinomas of the colon. Am J Physiol Gastrointest Liver Physiol 2006; 290:G1067-74. [PMID: 16399877 DOI: 10.1152/ajpgi.00234.2005] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
As for other mRNA measurement methods, quantitative RT-PCR results need to be normalized relative to stably expressed genes. Widely used normalizing genes include beta-actin and glyceraldehyde-3-phosphate dehydrogenase. It has, however, become clear that these and other normalizing genes can display modulated patterns of expression across tissue types and during complex cellular processes such as cell differentiation and cancer progression. Our objective was to set the basis for identifying normalizing genes that displayed stable expression during enterocytic differentiation and between healthy tissue and adenocarcinomas of the human colon. We thus identified novel potential normalizing genes using previously generated cDNA microarray data and examined the alterations of expression of two of these genes as well as seven commonly used normalizing genes during the enterocytic differentiation process and between matched pairs of resection margins and primary carcinomas of the human colon using real-time RT-PCR. We found that ribosomal phosphoprotein P0 was particularly stable in all intestinal epithelial cell extracts, thereby representing a particularly robust housekeeping reference gene for the assessment of gene expression during the human enterocytic differentiation process. On the other hand, beta-2-microglobulin generated the best score as a normalizing gene for comparing human colon primary carcinomas with their corresponding normal mucosa of the resection margin, although others were found to represent acceptable alternatives. In conclusion, we identified and characterized specific normalizing genes that should significantly improve quantitative mRNA studies related to both the differentiation process of the human intestinal epithelium and adenocarcinomas of the human colon. This approach should also be useful to validate normalizing genes in other intestinal contexts.
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Affiliation(s)
- Anders Bondo Dydensborg
- Canadian Institutes of Health-Research Group in Functional Development and Physiopathology of the Digestive Tract, and Département d'Anatomie et de Biologie Cellulaire, Faculté de Médecine, Université de Sherbrooke, Sherbrooke, Québec, Canada J1H 5N4
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400
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Chen J, Rider DA, Ruan R. Identification of valid housekeeping genes and antioxidant enzyme gene expression change in the aging rat liver. J Gerontol A Biol Sci Med Sci 2006; 61:20-7. [PMID: 16456191 DOI: 10.1093/gerona/61.1.20] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Valid housekeeping genes (HKG) are a prerequisite for accurate gene quantification. We performed real-time reverse transcription-polymerase chain reaction to investigate the gene expression of five commonly used HKGs (beta-actin, glyceraldehyde-3-phosphate dehydrogenase [GAPDH], ubiquitin C [UBC], hypoxanthine phosphoribosyl-transferase [HPRT], and cyclophilin A [CYPa]) and antioxidant enzymes in the liver of young and old male Fischer rats. A wide variation in HKG expression existed during the aging process, and HPRT was identified as the most stable HKG in rat liver aging. When Cu/Zn-superoxide dismutase gene expression was normalized to HPRT, there was no detectable difference between young and old rats; however, a significant difference was seen when it was normalized to UBC. The variation of UBC caused the misinterpretation of Cu/Zn-superoxide dismutase expression. Catalase expression was significantly decreased, whereas glutathione peroxidase expression was not altered with age. We demonstrated that HPRT was an appropriate HKG, validation of HKGs was vital for accurate quantification, and decreased catalase expression might be involved in the decline of antioxidant defenses during rat liver aging.
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Affiliation(s)
- Jie Chen
- Department of Otolaryngology, National University Hospital, Singapore
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