Download or read book Identification and Cloning a Novel Tumor Suppressor Gene in Breast Cancer written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: On the basis of an extensive body of cytogenetic literature as well as molecular evidence from our laboratory, we hypothesize that a tumor suppressor gene is located on the long arm of Human Chromosome 7 at the q3 1.1 band. Furthermore, we propose that inactivation of this tumor suppressor gene plays a role in the development of breast cancer. The long term objectives of the study are to identify and clone the tumor suppressor gene and to determine its function. The objectives for the requested funding period are to provide functional evidence for the existence of this tumor suppressor gene in breast cancer using microcell fusion and to clone the DNA fragment containing the putative tumor suppressor gene using a novel approach based on the introduction of Yeast Artificial Chromosomes (YACs) into breast cancer cells. This novel approach will facilitate the cloning of putative tumor suppressor genes closing the technical gaps that exist between the identification of deleted regions of genome containing putative tumor suppressor genes and the actual cloning of DNA fragments containing the candidate genes.
Download or read book Identification of Novel Tumor Suppressor Genes in Breast Cancer Using Gene Tapping Technique written by Leia M. Smith and published by . This book was released on 2001 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cancer is a multi-step process resulting from a number of genetic changes in cells. The role of tumor suppressor genes in breast carcinogenesis, especially at the early stage, remains largely unknown. We hypothesize that during the transformation of a breast epithelial cell, loss of function of several yet unidentified genes (tumor suppressors) results in either a partially or fully transformed phenotype. The aim of this study is to identify% novel tumor suppressor genes involved in breast epithelial transformation using the gene-trapping technique. We used the polyA-trap retroviral vector pRET for infection into non-tumorigenic human mammary epithelial cells MCF 1 0A. We screened for clones where functional genes have been "trapped" by selection for G4 18-resistance. We essentially established a gene-trapped library of MCF 1 0A clones where expression of a single gene per clone is disrupted. We screened for transformed clones using the soft-agar cloning assay for anchorage independent growth. We isolated 25 transformed clones and identified the trapped genes in 5 clones by rapid amplification of cDNA ends (3 RACE). We identified 2 known genes and 2 novel genes as putative tumor suppressor genes. Further characterization of these genes will elucidate their role in the early transformation process in breast epithelial cells.
Download or read book Identification of BRCA1 and 2 Other Tumor Suppressor Genes on Chromosome 17 Through Positional Cloning written by and published by . This book was released on 2000 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall goal of this project is to identify genes involved with the development and progression of breast cancer. This goal has remained unchanged since the start of the project, however the discovery of BRCA1 in 1994 together with technological advances in gene expression profiling has influenced our strategy to achieve this goal. In the early part of the project our search for tumor suppressor genes was directed by genetic or LOH mapping strategies followed by positional cloning of candidate genes. As we proposed in our revised statement of work (SOW), we have now focused our efforts entirely on microarray-based comparisons to identify breast cancer related genes. Our laboratory has gained access to this technology through collaboration with Molecular Dynamics and now we have established microarray spotting and scanning systems with over 40,000 minimally redundant sequence-verified human cDNA clones. Once candidate genes have been identified, they will be further characterized using a retroviral-based conditional expression system to assess changes in characteristics pertaining to morphology and growth rate by culturing human breast epithelial cells in an extracellular matrix.
Download or read book Tumor Suppressor Genes written by Wafik S. El-Deiry and published by Springer Science & Business Media. This book was released on 2008-02-03 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: It has become clear that tumors arise from excessive cell proliferation and a c- responding reduction in cell death. Tumors result from the successive accumulation of mutations in key regulatory target genes over time. During the 1980s, a number of oncogenes were characterized, whereas from the 1990s to the present, the emphasis shifted to tumor suppressor genes (TSGs). It has become clear that oncogenes and tumor suppressor genes function in the same pathways, providing positive and ne- tive growth regulatory activities. The signaling pathways controlled by these genes involve virtually every process in cell biology, including nuclear events, cell cycle, cell death, cytoskeletal, cell membrane, angiogenesis, and cell adhesion effects. Tumor suppressor genes are mutated in hereditary cancer syndromes, as well as somatically in nonhereditary cancers. In their normal state, TSGs control cancer development and p- gression, as well as contribute to the sensitivity of cancers to a variety of therapeutics. Understanding the classes of TSGs, the biochemical pathways they function in, and how they are regulated provides an essential lesson in cancer biology. We cannot hope to advance our current knowledge and to develop new and more effective therapies without understanding the relevant pathways and how they influence the present approaches to therapy. Moreover, it is important to be able to access the powerful tools now available to discover these genes, as well as their links to cell biology and growth control.
Download or read book Suppressor Genes in Breast Cancer written by and published by . This book was released on 1999 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several tumor suppressor genes (TSGs) have been cloned and found to be mutated in a variety of cancers, including breast cancer. However, few breast cancer specific TSGs are known. The purposes of this proposal are to: (1) generate cDNA expression libraries from reduction mammoplasties, (2) use a novel functional assay to clone new TSGs specific to human breast cancer, and (3) identify their characteristics, regulation and function. We are utilizing the tetracycline (tet) regulable system. We have constructed a cDNA library from normal human breast epithelia and cloned this cDNA library into a vector that is negatively regulated by tat repressor (tetR) and simultaneously expresses the enhanced green fluorescent protein. These vectors were then co-transfected into LCC6, MDA231, and MCF-7 cells that have the capability to express tetR. Upon withdrawal of tet, the repressed expression of the cDNA of interest is released, and the cDNA is expressed. Using a novel dye retained in nonproliferating cells, we were able to identify growth inhibited clones which were then sorted by Flow Cytometry. This functional screen has provided the basis for identifying TSGs that are expressed in the growth inhibited cells. Using PCR, we have obtained and sequenced two insert sequences. One is a putative TSG on chromosome #9 (725 bp) but the other sequence is vector DNA.
Download or read book Cloning of Tumor Suppressor Genes in Breast Cancer written by and published by . This book was released on 2003 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Breast cancer arises through the accumulation of genetic alterations that affect two classes of genes, oncogenes and tumor suppressor genes. These genes must be identified for several reasons. Characterization of the genes that drive carcinogenesis will facilitate a better understanding of cancer development. As part of this big picture, we have studied tumor suppressor genes involved in breast cancer. A tumor suppressor candidate, DBC2 was analyzed. DBC2 is a structurally new gene and its function remains to be studied. DBC2 is composed of a BAS domain, protein-protein interacting domains, and DNA binding domain. DBC2 expression is extinguished in more than half of breast tumors we tested. Methylation analysis of tumor cells revealed hypermethylation of the CpG islands in the DBC2 promoter region. Additionally, we have discovered somatic mutations of DBC2 in breast cancer. These mutations are accompanied by LOB. When DBC2 expression was induced in tumor cells, the cell growth was hindered. In contrast naturally occurring mutants did not suppress growth of the tumor cells. Our findings suggest that DBC2 is the target of mutations at 8p22.
Download or read book Identification of BRCAl and 2 Other Tumor Suppressor Genes on Chromosome 17 Through Positional Cloning written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the past year our project has evolved dramatically and significant progress has been make with respect to our overall goals of defining the genetic changes that distinguish normal cells from tumor cells of the breast. The most important evolution of the project is our change in strategy from identifying presumed tumor suppressor genes defined by loss of heterozygosity (LOH) using a positional cloning approach, to ascertaining and comparing genetic expression profiles from surgical specimens or cells grown in tissue culture using hybridization of cDNA from our tissues to microarrays of interesting genes. This is a very new technology and we are using a novel micro arraying and scanning instrument recently acquired by our laboratory in collaboration with Molecular Dynamics/Amersham. Preliminary experiments suggest that the sensitivity of our new microarray system is sufficiently high to allow us to detect variance in gene expression levels with high precision even under complex hybridization conditions. We have also applied the Differential Display protocol to identify three genes with altered expression in a model system of normal and neoplastic epithelial colonocytes. As an alternative to determining biologic effects of specific genes, we have tested and selected an amphoteric retroviral conditional expression system, which replaces previous experiments using antisense oligo's. We are confident that the 'modernization' of our research project will facilitate the identification of genes critical to the development and progression of breast cancer.
Download or read book Identification of Novel Tumor Suppressor Genes for Breast Cancer written by and published by . This book was released on 2006 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chromosomal deletions are very common events in breast cancer. However, no TSGs have been identified from most of recurrent deletions and few identified TSGs do not account for the risk of majority of breast cancer. In additional to the classical TSGs, there are haplo-insufficient TSGs which defy the identification through mutation analysis and may be quite common. By using a new system to generate random chromosomal deletions, we identified a ~3Mbp deletion in mouse chromosome 3, which was associated with tumorigenesis. The expression of Fat4 in the deleted region was inactivated due to promoter methylation in the second allele of Fat4, and the re-expression of Fat4 suppressed the tumorigenecity, suggesting Fat4 as a strong candidate for breast tumor suppressor genes. We also found that Fat4 expression was lost in a high proportion of human breast cancers, some of which were attributed to Fat4 promoter methylation.
Download or read book Identification of Two Candidate Tumor Suppressor Genes on Chromosome 17p13 3 Assessment of Their Roles in Breast and Ovarian Carcinogenesis written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Breast cancer is one of the most common malignancies affecting women in the US. Despite the magnitude of this disease little is known about the molecular events that occur during its development. We have identified a region of less than 30 kbp, on chromosome l7pl3.3 by allelic loss mapping, which is altered in>50% of the breast tumors analyzed. Using positional cloning techniques we have identified a gene, OVCA2, within this region, which we believe may be a tumor suppressor gene.
Download or read book Identification of Novel Tumor Suppressor Genes in Human Breast Cancer Using Nonsense Mediated MRNA Decay Inhibition NMDI Microarray Analysis written by and published by . This book was released on 2007 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project sought to identify genes that harbor nonsense mutations in breast cancer cell lines that are commonly used as in vitro models in the study of breast cancer biology, with the ultimate aim of identifying novel tumor suppressor genes for sporadic breast cancer. We focused our efforts on the long arm chromosome 22 which is known to undergo LOH in primary breast tumors. Before the NMD-microarray strategy could be undertaken, we very thoroughly characterized chromosome 22q copy number and allelic imbalance in several breast cancer cell lines by integrating publicly available genetic data with empirical data derived from 317K single nucleotide polymorphism (SNP) arrays. MCF-7, T-47D, and MDA-MB-231 breast cancer-derived cell lines were selected for NMD-microarray analysis. Two different regimens for inhibiting NMD were then directly compared for their ability to specifically inhibit NMD while leaving wild-type transcripts unaffected. The improved second-generation NMD protocol was performed and we eagerly await the results of the Affymetrix GeneChip expression arrays so that interrogation of the expression data may begin.
Download or read book Identification of Tumor Suppressor Genes in Breast Cancer by Insertional Mutagenesis and Functional Inactivation written by YAN. SU and published by . This book was released on 1998 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development and progression of cancer result from multiple genetic changes accumulated in the cells. The identification of tumor suppressor genes inactivated and proto-oncogenes activated in mammary epithelial cells is essential to understand the genetic basis of breast cancer and is a prerequisite for development of strategies for prevention, diagnosis, and treatment. In breast cancer, loss of heterozygosity (LOH) was detected frequently on chromosome 17 and other chromosomes, suggesting unrecognized tumor suppressor genes. We are applying the novel retroviral-tagging strategy to identify the genes using chromosome 17-suppressed (independent of p53 and BRCAl) breast cancer cell lines. In contrast to the parental tumorigenic cell line CAL51, the suppressed sublines CAL/17-3 and CAL/17-5 display retard growth in flasks, no growth in soft-agar culture and athymic nude mice. In this annual report, we present preparation of biological materials including cell culture, isolation of DNA and RNA, construction of cDNA library and packaging retrovirus particles. In order to provide antisense and mutant proteins to inhibit activities of tumor suppressor genes, poly-(A)+RNA was isolated from the suppressed subline CAL17-3 and used to construct the library. We are now in the process to package cDNA library into retrovirus particles for transduction.
Download or read book Cloning of Novel Oncogenes Involved in Human Breast Cancer written by Geoffrey Clark and published by . This book was released on 1998 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The genetic determinants which lie behind the development of breast cancer remain largely uncharacterized. In order to identify genes which may play a role in breast cancer we have begun a process of manufacturing cDNA expression libraries derived from human breast tumor cell lines in retroviral vectors. These libraries will be screened for their ability to induce a transformed phenotype in non-transformed or sub-transformed breast epithelial cells. The genes responsible for the transformation will be isolated with the goal of identifying important new markers for tumorigenesis which may serve as the targets for intervention or diagnosis.
Download or read book Molecular Genetics of Cancer written by John K. Cowell and published by Gulf Professional Publishing. This book was released on 2001 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the first volume was published, there has been significant success in isolating genes responsible for particular cancers as well as a major improvement in our understanding of the molecular events leading to tumors. This book explores possible genetic treatments that can suppress cancer cells that have formed tumors and it presents the details of the isolation and characterization of new human cancer genes that have recently been identified. Molecular Genetics of Cancer, 2E is an essential book for anyone involved in cancer research and the search for a cure.
Download or read book The Genetics of Cancer written by B.A. Ponder and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: It has been recognized for almost 200 years that certain families seem to inherit cancer. It is only in the past decade, however, that molecular genetics and epidemiology have combined to define the role of inheritance in cancer more clearly, and to identify some of the genes involved. The causative genes can be tracked through cancer-prone families via genetic linkage and positional cloning. Several of the genes discovered have subsequently been proved to play critical roles in normal growth and development. There are also implications for the families themselves in terms of genetic testing with its attendant dilemmas, if it is not clear that useful action will result. The chapters in The Genetics of Cancer illustrate what has already been achieved and take a critical look at the future directions of this research and its potential clinical applications.
Download or read book Genetic Alterations in Familial Breast Cancer Mapping and Cloning Genes Other Than BRCAl written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this project was to identify genes responsible for inherited predisposition to Breast cancer in families. The gene PTEN was successfully cloned by this project, and simultaneously by others (for a different reason) and proved to be such a gene. This project indicated that inherited mutations in PTEN predispose to breast cancer in women with the rare Cowden's syndrome. However, symptoms of that syndrome may be very subtle, so breast cancer may be the first sign to appear. Inherited mutations in PTEN predispose to multiple other cancers that may appear with breast cancer in these patients. Also, this project demonstrated the value of patients with germline translocations and breast cancer for the identification of tumor suppressor genes.
Download or read book A Breast Tumor Suppressor Gene on 8p22 Identification by the Genetic Suppressor Element Approach written by and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We are currently investigating a putative tumor suppressor gene (TSG) located at chromosomal band 8p22 that is involved in breast cancer. We have proposed to apply the genetic suppressor element (GSE) approach to the identification of this TSG. Briefly, a library of short gene fragments will be introduced into a cell line which demonstrates suppression of clonogenicity in soft agar with the transfer of chromosome 8. Presumably, the 8p22 TSG is responsible for the suppression of clonogenicity, and the introduction of an "active" GSE from the library into the suppressed cells should inhibit the 8p22 TSU contained in the hybrid cells and allow reversion back to the parental phenotype, the ability to grow in soft agar. Any clones that form will be isolated and further evaluated, as a candidate for the TSU. Currently, several ESTs have been identified in the 8p22 interval using various methods. Construction of the USE library consisting of these ESTs is currently underway. All preliminary optimization experiments for retroviral library delivery have been completed. Any positive USE clones identified will be characterized and evaluated as candidate TSGs.
Download or read book Molecular Genetics of Cancer written by John Cowell and published by Garland Science. This book was released on 2003-12-16 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular Genetics of Cancer, Second Edition provides an authoritative and up to date review of the key genes known to be critical in the development or progression of cancer. Throughout the book, scientific advances and their clinical relevance are covered in detail, particularly in the light of findings concerning the inheritance of genes predisposing to tumorigenesis. The book is therefore a valuable source of reference for clinicians and genetic counsellors as well as researchers.
