前沿科技及其它

Much progress has been made in understanding how matrix remodeling proteases, including metalloproteinases, serine proteases, and cysteine cathepsins, functionally contribute to cancer development. In addition to modulating extracellular matrix metabolism, protea ...

Proteolytic enzymes play an essential role in many biological and pathological processes. Taking advantage of the recent availability of several mammalian genome sequences and by using a set of computational approaches, we have annotated and compared the degradome or complete repe ...

The interplay between a protease and its substrates is controlled at many different levels, including coexpression, colocalization, binding driven by ancillary contacts, and the presence of natural inhibitors. Here we focus on the most basic parameter that guides substrate recogn ...

All proteases and peptidases are to some extent sequence-specific, in that one or more residues are preferred at particular positions surrounding the cleavage site in substrates. I describe here a general protocol for determining protease cleavage site preferences using mixture-b ...

Determining the preferred substrate cleavage sequence of proteases is an important step toward understanding their roles in cancer development and progression. Knowledge of this sequence can aid in the design of new experimental tools for study as well as aid in the identification of end ...

Expression of a given protease and of the endogenous inhibitors that regulate protease activity can be readily determined at the transcript level by using whole genome microarray chips. In the case of proteases and protease inhibitors, however, determining which cells are expressing t ...

The scarcity of methods to visualize the activity of individual cell surface proteases in situ has hampered basic research and drug development efforts. In this chapter, we describe a simple, sensitive, and noninvasive assay that uses nontoxic reengineered bacterial cytotoxins with a ...

Proteolysis is one of the most important post-translational modifications of the proteome with every protein undergoing proteolysis during its synthesis and maturation and then upon inactivation and degradation. Extracellular proteolysis can either activate or inactiva ...

The exuberant expression of proteinases by tumor cells has long been associated with the breakdown of the extracellular matrix, tumor invasion, and metastasis to distant organs. There are both epidemiological and experimental data that support a causative role for proteinases of the m ...

Gene expression analysis provides an insight into the unique and defining biomolecular characteristics of a given cell type. However, heterogeneous cellular compositions hinder gene analysis studies from most tissue samples. The laser microdissection (LMD) technique allows ...

Described are four widely used procedures to analyze the cell cycle by flow cytometry. The first two are based on univariate analysis of cellular DNA content following cell staining with either propidium iodide (PI) or 4′,6′-diamidino-2-phenylindole (DAPI) and deconvolution of the cell ...

The invasion and metastasis of tumor cells has been shown to require proteolytic activity in order to degrade components of the extracellular matrix (ECM). The hydrolysis of the ECM appears to facilitate tumor cell migration contributing to the metastatic dissemination of malignant ce ...

Baker’s yeast or Saccharomyces cerevisiae is the most intensely studied eukaryotic microorganism for very good reasons. Many fundamental processes such as cell cycle control and DNA repair show evolutionary conservation from yeast to human, thus making studies in yeast highly rele ...

The immune system is capable of recognizing and rejecting autologous tumor cells. This is suggested by reported cases of spontaneous remission of various cancers (1) and the presence of infiltrating leukocytes, the majority of which consist of T cells. However, the very existence of cancer a ...

Interference with the innate apoptotic activity is a hallmark of neoplastic transformation and tumor formation. Modulation of the apoptotic cascade has been proposed as a new approach for the treatment of cancer. In this chapter, we discuss the role of apoptosis in ovarian cancer and the use of p ...

Most authors currently quantify the frequency of apoptotic cells in a given phenotypically defined population after calculating the apoptotic index (AI), that is, the percentage of apoptotic cells displaying a specific lineage antigen (LAg) within a population of cells that remain un ...

A number of methods have been developed to identify the cells that undergo apoptosis by analyzing the morphological, biochemical, and molecular changes that take place during this universal biological process. The best recognized biochemical hallmark of both early and late stages of a ...

Tumors are heterogeneous structures that contain different cell populations. Laser capture microdissection (LCM) can be used to obtain pure cancer cells from fresh-frozen cancer tissue and the surrounded environment, thus providing an accurate snapshot of the tumor and its microe ...

Apoptosis (programmed cell death) is an active process that plays a critical role in multiple biologic processes from embryologic development, to lymphocyte development and selection, and homeostasis. The two major mechanisms of cell death are referred to as the intrinsic and extrins ...

The ChemoFx� Assay is an ex vivo assay designed to predict the sensitivity and resistance of a given patient’s solid tumor to a variety of chemotherapy agents. A portion of a patient’s solid tumor, as small as a core biopsy, is mechanically disaggregated and established in primary culture where malig ...