前沿科技及其它

Radioimmunohistochemistry was developed for quantitation of epidermal growth factor receptors (EGFR) and the c-erbB-2 protein and applied in breast tumors. With appropriate preliminary development, the method can be extended to other antigens and tissues. Radioimmunohist ...

Several assays exist to determine receptor status in ovarian cancers, like radio ligand binding assays, biochemical analysis, and even Northern blotting. However, patholo- gists generally prefer to judge the presence of biological markers in the context of tissue architecture, usi ...

Immunohistochemistry is the study of the intracellular distribution of antigens based on the formation of an immune complex. The concept is based on the application of a specific antibody to the antigen to be detected and visualization of the antigen-antibody reaction with a staining proc ...

Delineation of downstream signal transduction pathways is important for determining which intracellular signals contribute to the malignant phenotype of cancer cells. In this review, we discuss current methodologies used to study cell signaling. A number of factors that may infl ...

In cytokine receptors, there is no consensus sequence motif for tyrosine and/or serine/threonine kinases in its intracellular domain (1). Cytokine receptors associate with and activate members of the Janus kinase family (JAK), which is phosphorylated following ligand binding (2). T ...

The epidermal growth factor receptor (EGFr) is a 170-kDa glycosylated transmembrane protein found in a wide variety of tissues (1). It is the receptor for epidermal growth factor (EGF), transforming growth factor α (TGFα), and other related growth factor peptides (2,3). In 1980, EGF binding acti ...

The epidermal growth factor receptor (EGFR) (ErbB) family of receptor tyrosine kinases is frequently overexpressed in ovarian cancer (1) . This receptor group is comprised of four members, EGFR (ErbB-1), HER2 (ErbB-2), HER3 (ErbB-3), and HER4 (ErbB-4). These receptors share a common molecular ...

An important convergence point involved in the signal transduction pathways of many different growth factors, hormones, and cytokines are the p42 and p44 serine/ threonine kinases called either MAP kinases (mitogen-activate protein kinases) or ERK 1 and ERK 2 (extracellular regulat ...

Phosphoinositides constitute less than 0.1% of total cellular lipids, yet accumulating evidence suggests that phosphoinositide has functions in cellular growth and proliferation in addition to a role as a second messenger precursor (1,2). Phosphatidylinositol (PtdIns) kina ...

The ability to fractionate nucleic acids and to determine which of them has sequences complementary to an array of DNA or RNA molecules is one of the most powerful tools of molecular biology. The Southern blot, named for its inventor, is a method for transferring size-fractionated DNA from a gel matrix ...

A number of cellular processes, including cell proliferation and differentiation, appear to be regulated by the phosphorylation of proteins on tyrosine residues (1,2). The level of tyrosine phosphorylation of intracellular protein substrates is determined by the balance of phos ...

Membrane-constituting phospholipids include glycerol phospholipids such as phos- phatidylcholine and phosphatidylinositol (PI) and sphingolipids. Recently, signal transduction starting from hydrolysis of these phospholipids have attracted attention as regu ...

Intracellular free Ca2+concentration (i) plays a critical role in regulating many diverse cellular functions including cell proliferation and programmed cell death (apoptosis) (1). An elevation in i activates enzymes (phospholipase A2, phospho- lipase D and some isoforms of prot ...

Protein kinases and phosphatases play an important role in a variety of cellular functions such as cell growth, development, and gene expression (1). It is estimated that one-third of the proteins in a typical mammalian cell are phosphorylated and about 200 protein kinases and 100 protein phos ...

Protein kinase C (PKC), a family of phospholipid-dependent serine/threonine kinases, plays a cardinal role in malignancy (1-5). PKC isozymes can be categorized into three groups: Group A or conventional (c) PKC: α, βI, βII, and γ; Group B or novel (n) PKC: δ, ε, η, θ, and �, and Group C or atypical (a) PKC: ζ and λ (ι) (1,3,4). Wher ...

Identification of individual cyclic AMP binding proteins in tumor cytosolic extracts is possibly owing to the ability of 32P-labeled 8-azido cyclic AMP to act as an effective analog of cAMP, to bind specifically to its protein effector sites, and on photo activation to incorporate covalent ...

The techniques presented in this chapter describe the experimental procedure for the identification of the nonrandom DNA fragmentation associated with apoptosis. The major benefits of this method are its ability to detect a low level of DNA fragmentation and its ability to detect large D ...

Physiological or programmed cell death plays an important role during a variety of physiological and pathological processes (1). It is an active form of cell death under tight regulation. Physiological cell death in mammals occurs during embryonic development of organs and tissues; for e ...

The ability of a cell to undergo apoptosis is crucial during development, tissue homeostasis, and in the pathogenesis and treatment of disease (1). To study apoptosis, it is important to be able to detect apoptotic cells reliably. Here we describe a method to detect apoptosis in vitro and in vivo on basis ...

Apoptotic cells were originally recognized by their characteristic morphology. Since then, a series of biochemical changes have been described. However, it has yet to be established whether any of these changes unequivocally identify an apoptotic cell. In any study of apoptosis, it is imp ...