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Untitled Document
CANCER GENOMICS & PROTEOMICS
Volume 4, Number
6, November-December 2007
| CONTENTS |
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| Concurrent Down-regulation of Egr-1 and Gelsolin in the Majority of Human Breast Cancer Cells. J. LIU, Y.-G. LIU, R. HUANG, C. YAO, S. LI, W. YANG, D. YANG, R.-P. HUANG (Atlanta, GA, USA; Guangzhou, P.R. China) |
377 |
| IL-6 Enhances the Nuclear Translocation of DNA Cytosine-5-Methyltransferase 1 (DNMT1) via Phosphorylation of the Nuclear Localization Sequence by the AKT Kinase. D.R. HODGE, E. CHO, T.D. COPELAND, T. GUSZCZYNSKI, E. YANG, A.K. SETH, W.L. FARRAR (Frederick, MD, USA; Toronto, ONT, Canada) |
387 |
| Molecular Subgroups of Small (pT1) Breast Carcinomas Belonging Exclusively to the Ductal Infiltrating Variety. J. SCHNEIDER, A. TEJERINA, C. PEREA, R. LUCAS, J. SANCHEZ (Madrid; Alcorcon, Spain) |
399 |
| Characterization of Microarray Gene Expression Profiles of Early Stage Thyroid Tumours. K. GOMBOS, E. SZELE, I. KISS, T. VARJAS, L. PUSKAS, L. KOZMA, F. JUHASZ, E. KOVACS, I. SZANYI, I. EMBER (Pecs; Szeged; Debrecen, Hungary) |
403 |
| Irradiated Breast Cancer Patients Demonstrate Subgroup-specific Regularities in Protein Expression Patterns of Circulating Leukocytes. K. YEGHIAZARYAN, S. MAMLOUK, D. TROG, H. MOENKEMANN, M. BRAUN, W. KUHN, H.H. SCHILD, O. GOLUBNITSCHAJA (Bonn, Germany) |
411 |
| Standardization for Transcriptomic Molecular Markers to Screen Human Colon Cancer. F.E. AHMED, P.W. VOS, S. IJAMES, D.T. LYSLE, G. FLAKE, D.R. SINAR, W. NAZIRI, S.P. MARCUARD (Greenville; Chapel Hill; Research Triangle Park, NC, USA |
419 |
CANCER GENOMICS & PROTEOMICS 4: 377-386 (2007)
Concurrent Down-regulation of Egr-1 and Gelsolin in the Majority of Human Breast Cancer Cells
JINGBO LIU1, YA-GUANG LIU1, RUOCHUN HUANG1, CHEN YAO2,
SHIYONG LI3, WEIMIN YANG1, DONGZI YANG4
and RUO-PAN HUANG1
Departments of 1Gynecology and Obstetrics, and 2Pathology and Laboratory Medicine,
Emory University School of Medicine, Atlanta, GA, U.S.A.
Departments of 3Surgery, First Affiliated Hospital, and 4Gynecology and Obstetrics, Second Affiliated Hospital,
Sun Yat-sen University, Guangzhou, P.R. China
Abstract: A growing body of evidence suggests that early growth response-1 (Egr-1), a transcription factor, may function as a tumor suppressor. The aim of this study was to gain more evidence to support the role of Egr-1 in the suppression of cancer cell growth and to examine the potential correlation between Egr1 and gelsolin. Materials and Methods: Histochemical staining coupled with breast cancer tissue arrays were used to examine the expression levels of Egr-1 and gelsolin. Reporter assays and gel shift were used to study the transcriptional activity of Egr-1 on the regulation of gelsolin. Results: Our data showed that most normal mammary tissues expressed high levels of Egr-1, while the majority of breast cancer tissues expressed very small amounts of Egr-1. The expression pattern of Egr-1 in human breast cancer tissues was highly correlated with gelsolin expression. Induction of Egr-1 by serum stimulation accompanied the increase of gelsolin expression. In cells lacking the induction of Egr-1 in response to serum stimulation, gelsolin expression remained unchanged. Furthermore, gelsolin promoter activity was profoundly reduced in Egr-1 null mouse embryonic fibroblasts compared to Egr-1 wild-type mouse embryonic fibroblasts. Gel shift experiments indicated that Egr-1 can directly bind to the gelsolin promoter. Conclusion: Our results suggest that Egr-1 may be an important breast cancer marker and that an as yet uncharacterized pathway involved in Egr-1 and gelsolin expression exists which leads to breast cancer cell development.
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CANCER GENOMICS & PROTEOMICS 4: 387-398 (2007)
IL-6 Enhances the Nuclear Translocation of DNA Cytosine-5-Methyltransferase 1 (DNMT1) via Phosphorylation of the Nuclear Localization Sequence by the AKT Kinase
DAVID R. HODGE1, EDWARD CHO2, TERRY D. COPELAND3, TAD GUSZCZYNSKI3,
ERIC YANG4, ARUN K. SETH4 and WILLIAM L. FARRAR1
1Laboratory of Cancer Prevention, Cancer Stem Cell Section, Center for Cancer Research, and
3Laboratory of Protein Dynamics and Signaling, Protein Chemistry Core Facility, The National Cancer Institute at Frederick, Frederick, Maryland, 21702; 2Image Analysis Laboratory, Confocal Microscopy Laboratory, SAIC Frederick, Maryland 21702, USA; 4Laboratory of Molecular Pathology, University of Toronto, Sunnybrook Health Sciences Center, Toronto, Ontario, Canada M4N 3M5
Abstract: The epigenetic programming of genomic DNA is accomplished, in part, by several DNA cytosine-5methyltransferases that act by covalently modifying cytosines with the addition of a methyl group. This covalent modification is maintained by the DNA cytosine-5-methyltransferase-1 enzyme (DNMT1), which is capable of acting in concert with other similar enzymes to silence important tumor suppressor genes. IL-6 is a multifunctional mediator of inflammation, acting through several major signaling cascades, including the phosphatidylinositol-3-kinase pathway (PI-3-K), which activates protein kinase B (AKT/PKB) downstream. Here, we show that the subcellular localization of DNMT1 can be altered by the addition of IL-6, increasing the rate of nuclear translocation of the enzyme from the cytosolic compartment. The mechanism of nuclear translocation of DNMT1 is greatly enhanced by phosphorylation of the DNMT1 nuclear localization signal (NLS) by PKB/AKT kinase. Mutagenic alteration of the two AKT target amino acids within the NLS results in a major loss of DNMT1 nuclear translocation, while the creation of a "phospho-mimic" amino acid (mutation to acidic residues) restores this compartmentation ability. These observations suggest an interesting hypothesis regarding how mediators of chronic inflammation may disturb the delicate balance of cellular compartmentalization of important proteins, and reveals a potential mechanism for the induction or enhancement of tumor growth via alteration of the components involved in the epigenetic programming of a cell.
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CANCER GENOMICS & PROTEOMICS 4: 399-402 (2007)
Molecular Subgroups of Small (pT1) Breast Carcinomas Belonging Exclusively to the Ductal Infiltrating Variety
JOSÉ SCHNEIDER 1,2, ARMANDO TEJERINA 1, CLEMENTE PEREA 1,
RAÚL LUCAS 1 and JAIME SÁNCHEZ 1,3
1Centro de Patologia de la Mama, Madrid; 2Universidad Rey Juan Carlos,
Facultad de Ciencias de la Salud, Alcorcon, Madrid;
3Universidad de Alcala, Alcala de Henares, Madrid, Spain
Abstract: Background: The use of microarray technology has resulted in a new classification of breast cancer according to gene expression profiles. None of the reports published so far using this new classification has stratified the studied tumors by histology or size. Materials and Methods: This study was restricted to the ductal infiltrating variety only, and to pT1 size using the immunohistochemical markers estrogen receptor (ER), progesterone receptor (PR), HER2 and cytokeratin 5/6. ER+ and/or PR+, HER2- tumors were termed "luminal A"; ER+ and/or PR+, HER2+ "luminal B"; triple-negative, CK 5/6+ and/or HER1+ "basal-like"; with an additional category for ER-, PR-, HER2+ tumors termed HER2, and a final group of unclassified ones, negative for all five markers. Results: Out of 346 tumors, 251 (72.5%) were luminal A, 45 (13%) were "triple-negative" ("basal"-like), 20 (5.8%) were luminal B, and 30 (8.7%) were HER2. Luminal A, "triple-negative" ("basal"like), and HER2-expressing tumors (luminal B + HER2) showed significantly different associations with histological and nuclear grade, mutant p53 expression and Ki67 labelling index. Conclusion: Studies of the other, less frequent histological varieties of breast cancer, stratifying by tumor size, are mandatory to disclose which precise gene-expression pattern defines similar subgroups.
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CANCER GENOMICS & PROTEOMICS 4: 403-410 (2007)
Characterization of Microarray Gene Expression Profiles of Early Stage Thyroid Tumours
KATALIN GOMBOS1, ESZTER SZELE1, ISTVÁN KISS1, TÍMEA VARJAS1,
LÁSZLÓ PUSKÁS2, LÁSZLÓ KOZMA3, FERENC JUHÁSZ4, ERIK KOVÁCS5,
ISTVÁN SZANYI6 and ISTVÁN EMBER1
1Institute of Public Health, Faculty of Medicine, 5Heart Institute and First Department
of Internal Medicine and 6Department of Otolaryngology Head and Neck Surgery,
Faculty of Medicine, University of Pecs, Pecs; 2Functional Genomical Laboratory,
Biological Research Center of Hungarian Academy of Sciences, Szeged;
3Regional Blood Transfusion Center of Debrecen, Debrecen;
4First Department of Surgery, University of Debrecen,
Faculty of Medicine, Debrecen, Hungary
Abstract: Background: Microarray analysis offers the opportunity of screening transcriptional expression profile of neoplastic cells on a genomic level. Defining consistent changes in gene expression pattern of tumours enables the detection of genes essential for tumorigenesis and might provide biomarkers to early recognition of malignant behaviour and new therapeutical targets. Patients and Methods: A high-density oligonucleotide array with 20,000 human gene-specific oligonucleotide was used to analyze benign and early-stage malignant thyroid tumours of epithelial origin: follicular adenoma, follicular carcinoma and papillary carcinoma, compared to normal thyroid tissue. Results: Significant expression differences of 279 genes - underexpression of 252 and overexpression of 27 genes - were found. The overlapping genes of the different histological types were examined extensively. Among these genes a limited set acting on the same transcriptional pathway, through NF-ęB, were found. Conclusion: The role of overlapping genes in histologically different tumours has not been clarified, but might represent early or pivotal steps of carcinogenesis. All investigated histiotypes of tumours contained significantly modulated genes acting on the NF-ęB regulatory pathway. Our findings suggest that modulation of NF-ęB signalling plays a crucial role in early thyroid carcinogenesis.
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CANCER GENOMICS & PROTEOMICS 4: 411-418 (2007)
Irradiated Breast Cancer Patients Demonstrate Subgroup-specific Regularities in Protein Expression Patterns of Circulating Leukocytes
KRISTINA YEGHIAZARYAN1, SOULAFA MAMLOUK1, DANIELA TROG1,
HEIKE MOENKEMANN1, MICHAEL BRAUN2, WALTER KUHN2,
HANS H. SCHILD1,3 and OLGA GOLUBNITSCHAJA1,3
Departments of 1Radiology and 2Gynecology, and
3Center of Excellence for Breast Cancer Research,
Friedrich Wilhelms University of Bonn, D-53105 Germany
Abstract: Background: Breast cancer is one of the most frequent types of cancer with fatal outcome worldwide. The use of breast conserving lumpectomy followed by radiation therapy is common and has been shown to be a strategy competitive to mastectomy in preventing mortality caused by breast cancer. However, breast irradiation, particularly applied after pre-irradiation chemotherapy, frequently leads to serious short- and long-term side-effects, the prediction of which is highly desirable in terms of individual therapy planning. For these purposes, minimal-invasive molecular blood analysis is considered as a powerful diagnostic tool: molecular interplay in blood is highly informative and may predict individual side-effects of therapy. Materials and Methods: Ex vivo comparative protein expression profiling was performed in circulating leukocytes isolated from fresh blood samples of seven breast cancer patients before lumpectomy and consequently at several checkpoints under radiation treatment (0-60 Gy). Protein expression patterns were investigated by two-dimensional polyacrylamide gel electrophoresis followed by protein spot identification using matrix assisted laser desorption/ ionisation - time of flight. Specific expression levels of highly affected differentially expressed proteins were quantified by Western blotting. Results: The radiation treatment caused individual extensive alterations in expression patterns of leukocytes in the patients tested. In particular, a key regulator of redox status, thioredoxin, and the free-radical detoxification cascade members, SOD-2 and catalase, were highly affected. In spite of the high diversity of individual expression levels, characteristic protein expression patterns were recognized and patients were grouped according to the similarities found. Conclusion: Characteristic expression patterns in circulating leukocytes might provide novel molecular targets for prediction of therapy side-effects and improve individual therapy planning for breast cancer patients, thus avoiding unnecessary and excessive treatment-related toxicity. Molecular candidates and specific patterns are demonstrated in this work.
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CANCER GENOMICS & PROTEOMICS 4: 419-432 (2007)
Standardization for Transcriptomic Molecular Markers to Screen Human Colon Cancer
FARID E. AHMED1, PAUL W. VOS2, STEPHANIE IJAMES3, DONALD T. LYSLE3,
GORDON FLAKE4, DENNIS R. SINAR5, WADE NAZIRI6 and STEFAN P. MARCUARD7
Departments of 1Radiation Oncology, Leo W. Jenkins Cancer Center and
5Internal Medicine, The Brody School of Medicine (BSOM)
at East Carolina University (ECU), Greenville, NC;
2Department of Biostatistics, School of Allied Health Sciences, ECU, Greenville, NC;
3Department of Psychology, University of North Carolina, Chapel Hill, NC;
4Laboratory of experimental Pathology, National Institute of Environmental Health Sciences, Research Triangle Park, NC;
6Carolina Physicians PA, Greenville, NC; 7Carolina Digestive Diseases PA, Greenville,
NC, U.S.A.
Abstract: Establishing test performance criteria for a transcriptomic colon cancer marker approach must be carried out in a standardized fashion in order tso ensure that the test will perform the same way in any laboratory, anywhere. Condition of sample preservation and shipping prior to total RNA extraction is critical, and we recommend preserving stool samples in an appropriate preservative and shipping them in cold packs so as to keep stools at 4<sup>o</sup>C. It is not necessary to isolate colonocytes to obtain adequate RNA for testing. It is, however, important to obtain samples from both mucin-rich and non-mucin rich to have a good representation of both left- and right-side colon cancers. Employing a commercial total RNA extraction kit that contains an RLT buffer from Qiagen Corporation (Valencia, CA, USA) removes bacterial RNA from stool preparations and results in a high yield of undegraded RNA of human origin. Genes selected based on the enormous resources of NCI's Cancer Genome Anatomy project give good results. Primers for PCR should span more than one exon. Use of semiquantitative PCR, preferably with several reference housekeeping genes of various copy numbers, depending on tested genes, should enhance confidence in the quantitative results. Having standardized the testing conditions in our ongoing work, it is now imperative that a larger prospective randomized clinical study utilizing stool and tissue samples derived from several control and colon cancer patients, to allow for statistically valid analyses, be conducted in order to determine the true sensitivity and specificity of the transcriptomic screening approach for this cancer whose incidence is on the rise worldwide.
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