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Biomedical subjects

R L Strausberg

Publications and source records attributed to R L Strausberg.

At least 19 recordsLinked to original sources

Gene discovery in oral squamous cell carcinoma through the Head and Neck Cancer Genome Anatomy Project: confirmation by microarray analysis.

The near completion of the human genome project and the recent development of novel, highly sensitive high-throughput techniques have now afforded the unique opportunity to perform a comprehensive molecular characterization of normal, precancerous, and malignant cells, including those derived from squamous carcinomas of the head and neck (HNSCC). As part of these efforts, representative cDNA libraries from patient sets, comprising of normal and malignant squamous epithelium, were generated and contributed to the Head and Neck Cancer Genome Anatomy Project (HN-CGAP). Initial analysis of the sequence information indicated the existence of many novel genes in these libraries [Oral Oncol 36 (2000) 474]. In this study, we surveyed the available sequence information using bioinformatic tools and identified a number of known genes that were differentially expressed in normal and malignant epithelium. Furthermore, this effort resulted in the identification of 168 novel genes. Comparison of these clones to the human genome identified clusters in loci that were not previously recognized as being altered in HNSCC. To begin addressing which of these novel genes are frequently expressed in HNSCC, their DNA was used to construct an oral-cancer-specific microarray, which was used to hybridize alpha-(33)P dCTP labeled cDNA derived from five HNSCC patient sets. Initial assessment demonstrated 10 clones to be highly expressed (>2-fold) in the normal squamous epithelium, while 14 were highly represented in the malignant counterpart, in three of the five patient sets, thus suggesting that a subset of these newly discovered transcripts might be highly expressed in this tumor type. These efforts, together with other multi-institutional genomic and proteomic initiatives are expected to contribute to the complete understanding of the molecular pathogenesis of HNSCCs, thus helping to identify new markers for the early detection of preneoplastic lesions and novel targets for pharmacological intervention in this disease.

Aged↗

An international database and integrated analysis tools for the study of cancer gene expression.

Researchers working collaboratively in Brazil and the United States have assembled an International Database of Cancer Gene Expression. Several strategies have been employed to generate gene expression data including expressed sequence tags (ESTs), serial analysis of gene expression (SAGE), and open reading-frame expressed sequence tags (ORESTES). The database contains six million gene tags that reflect the gene expression profiles in a wide variety of cancerous tissues and their normal counterparts. All sequences are deposited in the public databases, GenBank and SAGEmap. A suite of informatics tools was designed to facilitate in silico analysis of the gene expression datasets and are available through the NCI Cancer Genome Anatomy Project web site (http://cgap.nci.nih.gov).

DNA, Complementary↗

Transcriptional response to hypoxia in human tumors.

BACKGROUND: The presence of hypoxic regions within solid tumors is associated with a more malignant tumor phenotype and worse prognosis. To obtain a blood supply and protect against cellular damage and death, oxygen-deprived cells in tumors alter gene expression, resulting in resistance to therapy. To investigate the mechanisms by which cancer cells adapt to hypoxia, we looked for novel hypoxia-induced genes. METHODS: The transcriptional response to hypoxia in human glioblastoma cells was quantified with the use of serial analysis of gene expression. The time course of gene expression in response to hypoxia in a panel of various human tumor cell lines was measured by real-time polymerase chain reaction. Hypoxic regions of human carcinomas were chemically marked with pimonidazole. Immunohistochemistry and in situ hybridization were used to examine gene expression in the tumor's hypoxic regions. RESULTS: From the 24 504 unique transcripts expressed, 10 new hypoxia-regulated genes were detected-all induced, to a greater extent than vascular endothelial growth factor, a hypoxia-induced mitogen that promotes blood vessel growth. These genes also responded to hypoxia in breast and colon cancer cells and were activated by hypoxia-inducible factor 1, a key regulator of hypoxic responses. In tumors, gene expression was limited to hypoxic regions. Induced genes included hexabrachion (an extracellular matrix glycoprotein), stanniocalcin 1 (a calcium homeostasis protein), and an angiopoietin-related gene. CONCLUSIONS: We have identified the genes that are transcriptionally activated within hypoxic malignant cells, a crucial first step in understanding the complex interactions driving hypoxia response. Within our catalogue of hypoxia-responsive genes are novel candidates for hypoxia-driven angiogenesis.

Blotting, Western↗

Integration of cytogenetic landmarks into the draft sequence of the human genome.

We have placed 7,600 cytogenetically defined landmarks on the draft sequence of the human genome to help with the characterization of genes altered by gross chromosomal aberrations that cause human disease. The landmarks are large-insert clones mapped to chromosome bands by fluorescence in situ hybridization. Each clone contains a sequence tag that is positioned on the genomic sequence. This genome-wide set of sequence-anchored clones allows structural and functional analyses of the genome. This resource represents the first comprehensive integration of cytogenetic, radiation hybrid, linkage and sequence maps of the human genome; provides an independent validation of the sequence map and framework for contig order and orientation; surveys the genome for large-scale duplications, which are likely to require special attention during sequence assembly; and allows a stringent assessment of sequence differences between the dark and light bands of chromosomes. It also provides insight into large-scale chromatin structure and the evolution of chromosomes and gene families and will accelerate our understanding of the molecular bases of human disease and cancer.

Chromosome Aberrations↗

The Cancer Genome Anatomy Project: new resources for reading the molecular signatures of cancer.

The Cancer Genome Anatomy Project (CGAP) has built informational, technological, and physical resources to interface genomics with basic and clinical cancer research. The CGAP web site (http://cgap.nci.nih.gov) provides informatics tools for in silico analysis of the CGAP datasets as well as information for accessing each of the CGAP resources. Published in 2001 by John Wiley & Sons, Ltd.

Animals↗

In silico analysis of cancer through the Cancer Genome Anatomy Project.

The Cancer Genome Anatomy Project (CGAP) was designed and implemented to provide public datasets, material resources and informatics tools to serve as a platform to support the elucidation of the molecular signatures of cancer. This overview of CGAP describes the status of this effort to develop resources based on gene expression, polymorphism identification and chromosome aberrations, and we describe a variety of analytical tools designed to facilitate in silico analysis of these datasets.

Animals↗

Genome and genetic resources from the Cancer Genome Anatomy Project.

The Cancer Genome Anatomy Project (CGAP) is a collaborative network of cancer researchers with a common goal: to decipher the genetic changes that occur during cancer formation and progression. The project brings together several recent technologies capable of high-throughput analysis to help achieve this goal. Automated sequencing of cDNA libraries is a primary focus and is geared towards providing a comprehensive and annotated set of human and mouse transcribed sequences. This effort includes full-length transcript sequence generated by CGAP's new Mammalian Gene Collection initiative. Single nucleotide polymorphisms (SNPs) within human gene sequences (Genetic Annotation Initiative) and chromosomal rearrangements within cancer cells (Cancer Chromosome Aberration Project) are also being cataloged as part of CGAP. Finally, to help determine gene expression patterns related to cancer, CGAP provides a quantitative catalog of data through its SAGEmap initiative. The genome and genetic analysis tools listed in this review are all freely distributed by CGAP (http://cgap.nci.nih.gov/) without restriction.

Animals↗

SAGEmap: a public gene expression resource.

We have constructed a public gene expression data repository and online data access and analysis, WWW and FTP sites for serial analysis of gene expression (SAGE) data. The WWW and FTP components of this resource, SAGEmap, are located at http://www.ncbi.nlm.nih. gov/sage and ftp://ncbi.nlm.nih.gov/pub/sage, respectively. We herein describe SAGE data submission procedures, the construction and characteristics of SAGE tags to gene assignments, the derivation and use of a novel statistical test designed specifically for differential-type analyses of SAGE data, and the organization and use of this resource.

Databases, Factual↗

Identifying potential tumor markers and antigens by database mining and rapid expression screening.

Genes expressed specifically in malignant tissue may have potential as therapeutic targets but have been difficult to locate for most cancers. The information hidden within certain public databases can reveal RNA transcripts specifically expressed in transformed tissue. To be useful, database information must be verified and a more complete pattern of tissue expression must be demonstrated. We tested database mining plus rapid screening by fluorescent-PCR expression comparison (F-PEC) as an approach to locate candidate brain tumor antigens. Cancer Genome Anatomy Project (CGAP) data was mined for genes highly expressed in glioblastoma multiforme. From 13 mined genes, seven showed potential as possible tumor markers or antigens as determined by further expression profiling. Now that large-scale expression information is readily available for many of the commonly occurring cancers, other candidate tumor markers or antigens could be located and evaluated with this approach.

Algorithms↗

Genome-wide analysis of oral cancer--early results from the Cancer Genome Anatomy Project.

The Cancer Genome Anatomy Project (CGAP) is a large cooperative effort sponsored by the US National Institutes of Health designed to find, catalog and annotate genes that are expressed during cancer development. In the past 2 years, the CGAP has sequenced over 700,000 clones from approximately 140 cDNA libraries, resulting in the identification of over 30,000 new human genes. As a first step in applying this project to oral cancer we entered four cell lines--two from oral cancer, one from primary oral keratinocytes, and one from oral keratinocytes which had been immortalized by human papillomavirus. Libraries of cDNA were made and sequenced and the data were deposited in GenBank. The expressed genes were then identified where possible. The cell lines, and the total number of expressed genes that were cloned from each were: HN3 (oral cancer), 263 genes; HN4 (oral cancer), 550 genes; HN5 (primary keratinocytes), 237 genes; HN6 (immortalized keratinocytes), 408 genes. The total number of different genes that were found was 1160. A total of 38 new genes, of unknown function, were discovered. The data presented here represent a beginning of the application of the CGAP technology to oral cancer. Even though the data are still quite incomplete, they already represent a large quantity of new information and clones of potential utility to the oral cancer community, and provide a glimpse of the data sets to be forthcoming from the Project. It must therefore be expected that there will soon be a large expansion in the volume of data regarding the genetics of oral cancer. Those who study this disease must be prepared to develop new methods of analysis and storage for handling the oncoming volumes of information.

Clone Cells↗

A public database for gene expression in human cancers.

A public database, SAGEmap, was created as a component of the Cancer Genome Anatomy Project to provide a central location for depositing, retrieving, and analyzing human gene expression data. This database uses serial analysis of gene expression to quantify transcript levels in both malignant and normal human tissues. By accessing SAGEmap (http://www.ncbi.nlm.nih.gov/SAGE) the user can compare transcript populations between any of the posted libraries. As an initial demonstration of the database's utility, gene expression in human glioblastomas was compared with that of normal brain white matter. Of the 47,174 unique transcripts expressed in these two tissues, 471 (1.0%) were differentially expressed by more than 5-fold (P<0.001). Classification of these genes revealed functions consistent with the biological properties of glioblastomas, in particular: angiogenesis, transcription, and cell cycle related genes.

Brain↗

The mammalian gene collection.

The Mammalian Gene Collection (MGC) project is a new effort by the NIH to generate full-length complementary DNA (cDNA) resources. This project will provide publicly accessible resources to the full research community. The MGC project entails the production of libraries, sequencing, and database and repository development, as well as the support of library construction, sequencing, and analytic technologies dedicated to the goal of obtaining a full set of human and other mammalian full-length (open reading frame) sequences and clones of expressed genes.

Animals↗

Functional genomics: technological challenges and opportunities.

In April, the Merck Genome Research Institute and the National Cancer Institute's Cancer Genome Anatomy Project, both supporters of functional genomics technology development and research, brought together a group of 27 scientists working at the forefront of this new field. Here we report on the presentations, discussions, and outcomes from this highly interactive and stimulating meeting held at the Banbury Center.

Animals↗

The Cancer Genome Anatomy Project: EST sequencing and the genetics of cancer progression.

As the process of tumor progression proceeds from the normal cellular state to a preneoplastic condition and finally to the fully invasive form, the molecular characteristics of the cell change as well. These characteristics can be considered a molecular fingerprint of the cell at each stage of progression and, analogous to fingerprinting a criminal, can be used as markers of the progression process. Based on this premise, the Cancer Genome Anatomy Project was initiated with the broad goal of determining the comprehensive molecular characterization of normal, premalignant, and malignant tumor cells, thus making a reality the identification of all major cellular mechanisms leading to tumor initiation and progression ([Strausberg, R.L., Dahl, C.A., and Klausner, R.D. (1997). "New opportunities for uncovering the molecular basis of cancer." Nat. Genet., 16: 415-516.], www.ncbi.nlm.nih.gov/ncicgap/). The expectation of determining the genetic fingerprints of cancer progression will allow for 1) correlation of disease progression with therapeutic outcome; 2) improved evaluation of disease treatment; 3) stimulation of novel approaches to prevention, detection, and therapy; and 4) enhanced diagnostic tools for clinical applications. Whereas acquiring the comprehensive molecular analysis of cancer progression may take years, results from initial, short-term goals are currently being realized and are proving very fruitful.

Databases, Factual↗