Nuclear matrix protein fluid assay

Abstract

Disclosed is a method for detecting and quantitating soluble nuclear matrix proteins in body fluids and extracellular media. The method is useful for monitoring the viability of cells and tissue, for evaluating the progress of a disease or its treatment, and for evaluating the cytotoxicity of unknown compounds. Also disclosed are methods for inducing the release of nuclear matrix proteins in soluble form from cells.

Description

BACKGROUND OF THE INVENTION This invention relates generally to the use of body fluid-soluble nuclear matrix proteins as cellular markers. More particularly, the invention relates to a method of monitoring the degree of cell death in a tissue by monitoring the level of interior nuclear matrix proteins and / or fragments thereof released from cells in a body fluid-soluble form. Cell death occurs as a function of healthy tissue homeostasis, as well as a result of disease or injury to the tissue. Detectable changes in the rate of cell death in a tissue therefore can provide an indication of the tissue's status. In normal growing tissue, for example, changes in the rate of cell death can indicate a new developmental stage. Alternatively, a sudden detected change in cell death in adult tissue can signal an injury to the tissue and also provide information on the type of injury. Previously, clinical assessment of tissue viability has required presentation of clinical symptoms and a visual...

AI Technical Summary

Benefits of technology

It now has been discovered that interior nuclear matrix proteins or soluble fragments thereof are released in soluble form from cells undergoing cell death. As used herein, “cell death” is understood to include both apoptosis (“programmed” cell death), and necrosis. Moreover, it also now has been discovered that these soluble forms of interior nuclear matrix proteins can be quantitated in a fluid and used to monitor the degree, or rate, of cell death in a tissue. The method of the invention also may be used to distinguish between types of cell death occurring. The presence of these proteins and protein fragments in solution in a body fluid soluble form is unexpected as the molecules comprise part of an insoluble nuclear complex under standard physiological conditions. The discovery of these proteins released in soluble form from dying cells allows one to use the soluble interior nuclear matrix proteins as biochemical monitors of tissue-specific cell death in fluid assays. The method is rapid and quantitative and can be used to evaluate the viability of cells and tissue, to evaluate progress of a disease and / or its treatment, to evaluate the cytotoxicity of unknown compounds and to study the kinetics of cell death. The discovery also provides an alternative method for purifying interior nuclear matrix proteins from cells.

In still another embodiment of the invention the method may be used to monitor the status of a cell culture and / or to assess the cytotoxicity of a compound by monitoring the levels of soluble interior nuclear matrix proteins or protein fragments released from these cells. Finally, the method also may be used to induce release of body fluid-soluble interior nuclear matrix proteins from intact cells, using compounds capable of inducing apoptosis, such as, for example, cytokines. A particularly useful cytokine is TNF (Tumor Necrosis Factor). This embodiment of the invention may be used to enhance identification of particular interior nuclear matrix proteins. It further may be used as part of a protocol to isolate soluble interior nuclear matrix proteins or protein fragments. Novel nuclear matrix proteins may be obtained by this method, as well as known or novel proteins useful as antigenic determinants in antibody production. Finally, the method of the invention may be useful as part of a protocol to identify candidate compounds useful as cancer chemotheapeutic agents (see infra.)

Problems solved by technology

Early stages of a malignancy therefore can be particularly difficult to detect by this method.

Biochemical assessments of cell or tissue viability also generally have been difficult to interpret, primarily because in many instances cell death occurs in individual cells which are intimately intermixed with viable cells in a sample.

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