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Biomedical subjects

Julia D Wulfkuhle

Publications and source records attributed to Julia D Wulfkuhle.

8 recordsLinked to original sources
PubMed2006

Technology insight: pharmacoproteomics for cancer--promises of patient-tailored medicine using protein microarrays.

Patient-tailored medicine can be defined as the selection of specific therapeutics to treat disease in a particular individual based on genetic, genomic or proteomic information. While individualized treatments have been used in medicine for years, advances in cancer treatment have now generated a need to more precisely define and identify those patients who will derive the most benefit from new-targeted agents. Cellular signaling pathways are a protein-based network, and the intended drug effect is to disrupt aberrant protein phosphorylation-based enzymatic activity and epigenetic phenomena. Pharmacoproteomics, or the tailoring of therapy based on proteomic knowledge, will begin to take a central role in this process. A new type of protein array platform, the reverse-phase protein microarray, shows potential for providing detailed information about the state of the cellular 'circuitry' from small samples such as patient biopsy specimens. Measurements of hundreds of specific phosphorylated proteins that span large classes of important signaling pathways can be obtained at once from only a few thousand cells. Clinical implementation of these new proteomic tools to aid the clinical, medical and surgical oncologist in making decisions about patient care will now require thoughtful communication between practicing clinicians and research scientists.

Gene Expression Profiling↗
PubMed2005

Use of reverse phase protein microarrays and reference standard development for molecular network analysis of metastatic ovarian carcinoma.

Cancer can be defined as a deregulation or hyperactivity in the ongoing network of intracellular and extracellular signaling events. Reverse phase protein microarray technology may offer a new opportunity to measure and profile these signaling pathways, providing data on post-translational phosphorylation events not obtainable by gene microarray analysis. Treatment of ovarian epithelial carcinoma almost always takes place in a metastatic setting since unfortunately the disease is often not detected until later stages. Thus, in addition to elucidation of the molecular network within a tumor specimen, critical questions are to what extent do signaling changes occur upon metastasis and are there common pathway elements that arise in the metastatic microenvironment. For individualized combinatorial therapy, ideal therapeutic selection based on proteomic mapping of phosphorylation end points may require evaluation of the patient's metastatic tissue. Extending these findings to the bedside will require the development of optimized protocols and reference standards. We have developed a reference standard based on a mixture of phosphorylated peptides to begin to address this challenge.

Carcinoma↗
PubMed2005

Reverse-phase protein microarrays for tissue-based analysis.

The deciphering of the human genome has elucidated our biological structural design and has generated insights into disease development and pathogenesis. At the same time, knowledge of genetic changes during disease processes has demonstrated the need to move beyond genomics towards proteomics and a systems biology approach to science. Analyzing the proteome comprises more than just a numeration of proteins. In fact, it characterizes proteins within cells in the context of their functional status and interactions in their physiological micro- and macroenvironments. As dysregulated signaling often underpins most human diseases, an overarching goal of proteomics is to profile the working state of signaling pathways, to develop 'circuit maps' of normal and diseased protein networks and identify hyperactive, defective or inoperable transduction pathways. Reverse-phase protein microarrays represent a new technology that can generate a multiplex readout of dozens of phosphorylated events simultaneously to profile the state of a signaling pathway target even after the cell is lyzed and the contents denatured.

Animals↗
PubMed2003

Signal pathway profiling of ovarian cancer from human tissue specimens using reverse-phase protein microarrays.

Defects in cell signaling pathways play a central role in cancer cell growth, survival, invasion and metastasis. An important goal of proteomics is to characterize and develop "circuit maps" of these signaling pathways in normal and diseased cells. We have used reverse-phase protein array technology coupled with laser capture microdissection and phospho-specific antibodies to examine the activation status of several key molecular "gates" involved in cell survival and proliferation signaling in human ovarian tumor tissue. The levels of activated extracellular-regulated kinase (ERK1/2) varied considerably in tumors of the same histotype, but no significant differences between histotypes were observed. Advanced stage tumors had slightly higher levels of phosphorylated ERK1/2 compared to early stage tumors. The activation status of Akt and glycogen synthase kinase 3beta, key proteins and indicators of the state of the phosphatidylinositol 3-kinase/Akt pro-survival pathway also showed more variation within each histotype than between the histotypes studied. Our results demonstrate the utility of reverse phase protein microarrays for the multiplexed analysis of signal transduction from discreet cell populations of cells procured directly from human ovarian tumor specimens and suggest that patterns in signal pathway activation in ovarian tumors may be patient-specific rather than type or stage specific.

Biomarkers, Tumor↗
PubMed2003

Proteomic approaches to the diagnosis, treatment, and monitoring of cancer.

The field of proteomics holds promise for the discovery of new biomarkers for the early detection and diagnosis of disease, molecular targets for therapy and markers for therapeutic efficacy and toxicity. A variety of proteomics approaches may be used to address these goals. Two-dimensional gel electrophoresis (2D-PAGE) is the cornerstone of many discovery-based proteomics studies. Technologies such as laser capture microdissection (LCM) and highly sensitive MS methods are currently being used together to identify greater numbers of lower abundance proteins that are differentially expressed between defined cell populations. Newer technologies such as reverse phase protein arrays will enable the identification and profiling of target pathways in small biopsy specimens. Surface-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) analysis enables the high throughput characterization of lysates from very few tumor cells or body fluids and may be best suited for diagnosis and monitoring of disease. Such technologies are expected to supplement our arsenal of mRNA-based assays, and we believe that in the future, entire cellular networks and not just a single deregulated protein will be the target of therapeutics and that we will soon be able to monitor the status of these pathways in diseased cells before, during and after therapy.

Biomarkers, Tumor↗
PubMed2003

Proteomic applications for the early detection of cancer.

The ability of physicians to effectively treat and cure cancer is directly dependent on their ability to detect cancers at their earliest stages. Proteomic analyses of early-stage cancers have provided new insights into the changes that occur in the early phases of tumorigenesis and represent a new resource of candidate biomarkers for early-stage disease. Studies that profile proteomic patterns in body fluids also present new opportunities for the development of novel, highly sensitive diagnostic tools for the early detection of cancer.

Biomarkers, Tumor↗
PubMed2002

Proteomics of human breast ductal carcinoma in situ.

We report the first proteomic analysis of matched normal ductal/lobular units and ductal carcinoma in situ (DCIS) of the human breast. An understanding of the transition from normal epithelium to the first definable stage of cancer at the functional level of protein expression is hypothesized to contribute to improved detection, prevention, and treatment. Ten sets of two-dimensional gels were evaluated, containing either matched normal ductal/lobular units or DCIS from either whole tissue sections or up to 100,000 laser capture microdissected epithelial cells. Differential protein expression was confirmed by image analysis. Protein spots (315) were excised and subjected to mass spectrometry sequencing. Fifty-seven proteins were differentially expressed between normal ductal/lobular units and DCIS. Differences in overall protein expression levels and posttranslational processing were evident. Ten differentially expressed proteins were validated in independent DCIS specimens, and 14 of 15 proteomic trends from two-dimensional gel analyses were confirmed by standard immunohistochemical analysis using a limited independent tumor cohort. Many of the proteins identified were previously unconnected with breast cancer, including proteins regulating the intracellular trafficking of membranes, vesicles, cancer preventative agents, proteins, ions, and fatty acids. Other proteomic identifications related to cytoskeletal architecture, chaperone function, the microenvironment, apoptosis, and genomic instability. Proteomic analysis of DCIS revealed differential expression patterns distinct from previous nucleic acid-based studies and identified new facets of the earliest stage of breast cancer progression.

Breast Neoplasms↗