Catálogo de publicaciones - libros

Molecular profiling of tumors at the transcript or protein level has the potential of explaining the biology of tumors as well as classifying them in molecular terms for the purpose of more decisive diagnosis or prognosis, with respect to their aggressive, recurrence, or treatment response. In recent years, these approaches have been used for the study of gliomas, which are the most prevalent and lethal primary brain tumors. The studies on differential protein expression using 2DE/MS-based and other proteomic approaches, which are reviewed here, indicate their usefulness for future studies. We discuss the clinicopathological issues currently encountered with gliomas, the experimental approaches for protein profiling, experimental systems used to find molecular markers for gliomas, followed by a review of recent proteomics studies carried out by us and other investigators. A speculative scheme integrating the observations made in these studies is discussed and the chapter concludes with a perspective of the future developments that can come from constantly improving proteomics technologies.

Our research in immunotechnology focuses on the cells and molecules of the immune system for various biomedical applications. Applied research as well as projects addressing fundamental issues is being pursued within four main project areas: 1) antibody technology, 2) proteomics, 3) cancer, and 4) allergy. Within the proteomics project, we have taken advantage of the strong background in antibody engineering to design antibody-based micro- and nanoarrays for applications ranging from focused assays to proteome-scale analysis. Antibody-based microarray is a novel technology that holds great promise in proteomics. The microarray can be printed with thousands of recombinant antibodies carrying the desired specificities, the biological sample added (e.g., an entire proteome), and virtually any specifically bound analytes detected. The microarray patterns generated can then be converted into proteomic maps, or molecular fingerprints, revealing the composition of the proteome. Global proteome analysis and protein expression profiling, by using this tool, will provide new opportunities for biomarker discovery, drug target identification, and disease diagnostics and will give insight into disease biology. Ultimately, we apply this novel technology platform within our cancer and allergy projects to perform high-throughput disease proteomics.

In recent years, the importance of glycosylation has been realized. Carbohydrates not only serve as decoration for proteins and lipids but also form an integral part of the glycoconjugate, adding to its functional and structural properties. The specific type of glycosylation may change with altering physiological conditions, such as disease. Likewise, altering glycosylation may determine disease or disease properties. Studying glycosylation has long been a major problem, mainly because of the lack of proper analytical technology. Only minute quantities of the analytes are available from natural sources, and they cannot be amplified like DNA. The possibility of branching, different isomeric linkages, and the use of building blocks with the same mass lead to isomeric and isobaric structures. Lately, technology has become available that is able to differentiate these structures and that comforts enough sensibility and throughput to analyze samples from natural sources. DNA sequencer-aided fluorophore-assisted carbohydrate electrophoresis (DSA-FACE) is one of these new techniques with great potential. Here, we briefly introduce the method and discuss some of its applications in diagnosis of disease.

One of our long-term interests is to explore the immunogenic sugar moieties that are important for “self-” and “nonself” discrimination and host immune responses. We have established a highthroughput platform of carbohydrate microarrays to facilitate these investigations. Using this technology, carbohydrate-containing macromolecules of distinct structural configurations, including polysaccharides, natural glycoconjugates, and mono- and oligosaccharides coupled to lipid, polyacrylamide, and protein carriers, have been tested for microarray construction without further chemical modification. Here, we discuss issues related to the establishment of this technology and areas that are highly promising for its application. We also provide an example to illustrate that the carbohydrate microarray is a discovery tool; it is particularly useful for identifying immunological sugar moieties, including differentially expressed complex carbohydrates of cancer cells and stem cells as well as sugar signatures of previously unrecognized microbial pathogens.

Blood donation testing consists of a series of distinct assays determining compatibility of blood and blood products between donor and recipient as well as detecting potential contamination by life-threatening blood-borne pathogens. Current testing algorithms in developed countries provide extremely safe blood supply, although they are rather complex. Microarray technology has the potential to simplify the testing of algorithms by providing a single multiplex testing platform.

Dielectrophoresis (DEP)-based lab-on-a-chip devices represent a very appealing approach for cell manipulation and will enable laboratory testing to move from laboratories into nonlaboratory settings. DEP-based lab-on-a-chip platforms involve the miniaturization of several complex chemical and physical procedures in a single microchip-based device, allowing the identification and isolation of cell populations or single cells, separation of cells exhibiting different DEP properties, isolation of infected from uninfected cells, and viable from nonviable cells. In addition, DEP-arrays allow cellomics procedures based on the parallel manipulation of thousands of cells. Arrayed lab-on-a-chip platforms are also suitable to study cell-cell interactions and cell targeting with programmed numbers of microspheres.

The new genetics or—as it is often called—genomics is one of the most exciting and challenging areas of science today. It promises to revolutionize medicine and healthcare in the twenty-first century. We are now only just beginning to understand the genetic basis of common diseases; but the number of patients with the potential to be affected by genetic susceptibility and the capability to identify them using newer advances in genetics is rising rapidly. The simple rules of inheritance proposed by Gregor Mendel are no longer adequate to explain complex patterns of inheritance, reflecting intriguing phenomena such as mitochondrial inheritance and genomic imprinting. The distinction blurs between the genetic factors and the environment in the expression of the clinical phenotype. Genes are no longer thought to operate in isolation but to interact with each other and with the environmental milieu, both external and internal.

Mapping of the human genome, one of the greatest scientific developments, places researchers at the edge of a new frontier that is already yielding medical breakthroughs and shows promise for many others. The resultant discoveries have come to herald a new era wherein these new scientific advances are fast becoming an integral part of modern medicine and have led to an increased understanding of diseases. Contemporary aspects, such as molecular diagnostic testing for various single gene disorders, bacterial and viral identification, chromosome analysis in congenital anomalies, and DNA analysis for forensic and parental identification, have come to be regarded as representative and crucial facets of present standards of health care.

This chapter aims to create an interface among the subject, its students, and its practitioners at the field level, encompassing diverse walks of life, ranging from diagnostics to industrial and pharmaceutical applications, as well keeping pace with the current emerging developments and the challenges involved. It is fondly hoped that this will serve as a platform for further scientific inquiries and pave the way for the refinement of the discipline in the times ahead.