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Virginia Espina

Publications and source records attributed to Virginia Espina.

29 records · Page 2Linked to original sources
PubMed2004

Protein microarray detection strategies: focus on direct detection technologies.

Protein microarrays are being utilized for functional proteomic analysis, providing information not obtainable by gene arrays. Microarray technology is applicable for studying protein-protein, protein-ligand, kinase activity and posttranslational modifications of proteins. A precise and sensitive protein microarray, the direct detection or reverse-phase microarray, has been applied to ongoing clinical trials at the National Cancer Institute for studying phosphorylation events in EGF-receptor-mediated cell signaling pathways. The variety of microarray applications allows for multiple, creative microarray designs and detection strategies. Herein, we discuss detection strategies and challenges for protein microarray technology, focusing on direct detection of protein microarrays.

Animals↗
PubMed2004

Serum proteomics in cancer diagnosis and management.

Mass spectrometry-based diagnostics has the potential to revolutionize molecular medicine. Using modern mass-spectrometer technologies, clinical tests can be developed that are practical, robust, accurate, and inexpensive. Serum proteomic pattern profiling couples mass spectrometry with adaptive artificial-intelligence-based bioinformatics, which can now be employed to detect pathological states reflected in the serum proteome. With this approach, rapid and cost-effective tests with exquisite clinical sensitivity and specificity are emerging. These tools may dramatically change how disease is detected, monitored, and managed.

Blood Proteins↗
PubMed2004

Use of proteomic analysis to monitor responses to biological therapies.

Proteomics has the potential to revolutionise diagnosis and disease management. Serum protein pattern profiling by surface-enhanced laser desorption/ionisation time of flight (SELDI-TOF) mass spectrometry is emerging as a novel approach to discover protein patterns capable of distinguishing disease and disease-free states with high sensitivity and specificity. This method has shown great promise for early diagnosis of ovarian cancer and is being applied to a range of pathological states. Protein microarray technology is being evaluated as a new means to track biological responses to therapy. Through the measurement of key protein phosphorylation sites at different stages of disease progression or before and after treatment, protein signal pathways can be mapped and thus become the starting point for individualised therapy. Laser capture microdissection (LCM) coupled with immunostaining of protein microarrays allows isolation of pure cell populations and relative quantitation of phosphorylated and non-phosphorylated forms of the cell's key signalling proteins. This technology is currently in use at the National Institutes of Health in Phase II clinical trials of metastatic breast and ovarian cancer. Cell survival and apoptotic protein pathways are monitored as biological markers of disease progression in these clinical trials. Proteomic technologies, such as serum protein pattern profiling, combined with protein microarray technologies, constitute a new paradigm for detecting disease and monitoring disease response to therapy. Ultimately, proteomics and genomics will become integrated into cancer patient management through the design and tracking of individualised therapy.

Animals↗
PubMed2003

Proteomic profiling of the NCI-60 cancer cell lines using new high-density reverse-phase lysate microarrays.

Because most potential molecular markers and targets are proteins, proteomic profiling is expected to yield more direct answers to functional and pharmacological questions than does transcriptional profiling. To aid in such studies, we have developed a protocol for making reverse-phase protein lysate microarrays with larger numbers of spots than previously feasible. Our first application of these arrays was to profiling of the 60 human cancer cell lines (NCI-60) used by the National Cancer Institute to screen compounds for anticancer activity. Each glass slide microarray included 648 lysate spots representing the NCI-60 cell lines plus controls, each at 10 two-fold serial dilutions to provide a wide dynamic range. Mouse monoclonal antibodies and the catalyzed signal amplification system were used for immunoquantitation. The signal levels from the >30,000 data points for our first 52 antibodies were analyzed by using p-scan and a quantitative dose interpolation method. Clustered image maps revealed biologically interpretable patterns of protein expression. Among the principal early findings from these arrays were two promising pathological markers for distinguishing colon from ovarian adenocarcinomas. When we compared the patterns of protein expression with those we had obtained for the same genes at the mRNA level by using both cDNA and oligonucleotide arrays, a striking regularity appeared: cell-structure-related proteins almost invariably showed a high correlation between mRNA and protein levels across the NCI-60 cell lines, whereas non-cell-structure-related proteins showed poor correlation.

Blotting, Western↗
PubMed2003

Protein microarrays: molecular profiling technologies for clinical specimens.

Proteomics, the study of protein function within biologic systems, will further our understanding of cancer pathogenesis. Coupled with transcript profiling, proteomics can herald the advent of molecular therapy tailored to the individual patient's neoplasm. Protein microarrays, one emerging class of proteomic technologies, have broad applications for discovery and quantitative analysis. This technology is uniquely suited to gather information about the post-translational modifications of proteins reflecting the activity state of signal pathways and networks. Protein microarrays now make it feasible to conduct signal network profiling within cellular samples. Nevertheless, to be successful, design and use of protein microarrays must take into consideration enormous analytical challenges. A subclass of protein microarrays, Reverse Phase Arrays, created to meet these challenges, has been optimized for use with tissue specimens, and is now in use for the analysis of biopsy samples for clinical trial research.

Antibodies↗
PubMed2003

Protein microarrays: meeting analytical challenges for clinical applications.

Protein microarrays, one emerging class of proteomic technologies, have broad applications for discovery and quantitative analysis. A rapidly expanding use of this technology is the acquisition of information about the posttranslational modifications of proteins reflecting the activity state of signal pathways and networks, and is now employed for the analysis of biopsy samples in clinical trial research.

Animals↗
PubMed2003

Molecular diagnostics.

It is increasingly evident that molecular diagnostics, that is, the use of diagnostic testing to understand the molecular mechanisms of an individual patient's disease, will be pivotal in the delivery of safe and effective therapy for many diseases in the future. A huge body of new information on the genetic, genomic and proteomic profiles of different hematopoietic diseases is accumulating. This chapter focuses on new technologies and advancements in understanding the molecular basis of hematologic disorders, providing an overview of new information and its significance to patient care. In Section I, Dr. Braziel discusses the impact of new genetic information and research technologies on the actual practice of diagnostic molecular hematopathology. Recent and projected changes in methodologies and analytical strategies used by clinical molecular diagnostics laboratories for the evaluation of hematologic disorders will be discussed, and some of the challenges to clinical implementation of new molecular information and techniques will be highlighted. In Section II, Dr. Shipp provides an update on current scientific knowledge in the genomic profiling of malignant lymphomas, and describes some of the technical aspects of gene expression profiling. Analysis methods and the actual and potential clinical and therapeutic applications of information obtained from genomic profiling of malignant lymphomas are discussed. In Section III, Dr. Liotta presents an update on proteomic analysis, a new and very active area of research in hematopoietic malignancies. He describes new technologies for rapid identification of different important proteins and protein networks, and the potential therapeutic and prognostic value of the elucidation of these proteins and protein pathways in the clinical care of patients with malignant lymphomas.

Cytogenetic Analysis↗
PubMedDate not supplied

Pegylated, steptavidin-conjugated quantum dots are effective detection elements for reverse-phase protein microarrays.

Protein microarray technologies provide a means of investigating the proteomic content of clinical biopsy specimens in order to determine the relative activity of key nodes within cellular signaling pathways. A particular kind of protein microarray, the reverse-phase microarray, is being evaluated in clinical trials because of its potential to utilize limited amounts of cellular material obtained through biopsy. Using this approach, cellular lysates are arrayed in dilution curves on nitrocellulose substrates for subsequent probing with antibodies. To improve the sensitivity and utility of reverse-phase microarrays, we tested whether a new reporter technology as well as a new detection instrument could enhance microarray performance. We describe the use of an inorganic fluorescent nanoparticle conjugated to streptavidin, Qdot 655 Sav, in a reverse-phase protein microarray format for signal pathway profiling. Moreover, a pegylated form of this bioconjugate, Qdot 655 Sav, is found to have superior detection characteristics in assays performed on cellular protein extracts over the nonpegylated form of the bioconjugate. Hyperspectral imaging of the quantum dot microarray enabled unamplified detection of signaling proteins within defined cellular lysates, which indicates that this approach may be amenable to multiplexed, high-throughput reverse-phase protein microarrays in which numerous analytes are measured in parallel within a single spot.

Calibration↗
PubMedDate not supplied

Clinical proteomics: revolutionizing disease detection and patient tailoring therapy.

The evolving discipline of Clinical Proteomics is more than simply describing and enumerating the systematic changes in the protein constituency of a cell, or just generating lists of proteins that increase or decrease in expression as a cause or consequence of disease. Clinical applications of proteomics involve the use of proteomic technologies at the bedside with the ultimate goal to characterize the information flow through the intra- and extracellular molecular protein networks that interconnect organ and circulatory systems together. These networks are both new targets for therapeutics themselves as well as underpin the dynamic changes that give rise to cascades of new diagnostic biomarkers. The analysis of human cancer can be used as a model for how clinical proteomics is having an impact at the bedside for early detection, rational therapeutic targeting, and patient-tailored therapy.

Animals↗
PubMedDate not supplied

An interventional magnetic resonance imaging technique for the molecular characterization of intraprostatic dynamic contrast enhancement.

The biological characterization of an individual patient's tumor by noninvasive imaging will have an important role in cancer care and clinical research if the molecular processes that underlie the image data are known. Spatial heterogeneity in the dynamics of magnetic resonance imaging contrast enhancement (DCE-MRI) is hypothesized to reflect variations in tumor angiogenesis. Here we demonstrate the feasibility of precisely colocalizing DCE-MRI data with the genomic and proteomic profiles of underlying biopsy tissue using a novel MRI-guided biopsy technique in a patients with prostate cancer.

Biopsy↗