Biomaterial Database

Effect of p53 overexpression on radiation sensitivity of human colon cancer cells. 1997

R C Zellars, and J D Naida, and M A Davis, and T S Lawrence

Department of Radiation Oncology, University of Michigan, Ann Arbor 48109-0582, USA.

Substantial controversy surrounds our understanding of the effect of p53 status on radiation sensitivity. To assess directly the role of p53 expression on radiation sensitivity, we chose a conditional expression system using a temperature-sensitive murine p53 that permitted each cell line to act as its own control. We found that the conditional expression of wild type p53 induced cell death (both apoptotic and nonapoptotic), changes in cell cycle distribution (arrest in G1 and G2, which resulted in a marked depletion of S-phase cells and an increase in the fraction of cells in G2), and an increase in the radiation resistance of G1 cells. These counterbalancing effects resulted in no significant effect on overall radiosensitivity. These findings demonstrate that wild type p53 function can produce a variety of effects that can modulate radiation sensitivity and may explain why p53 status alone has not been a strong predictor of radiosensitivity.

UI	MeSH Term	Description	Entries
D011237	Predictive Value of Tests	In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.	Negative Predictive Value,Positive Predictive Value,Predictive Value Of Test,Predictive Values Of Tests,Negative Predictive Values,Positive Predictive Values,Predictive Value, Negative,Predictive Value, Positive
D011836	Radiation Tolerance	The ability of some cells or tissues to survive lethal doses of IONIZING RADIATION. Tolerance depends on the species, cell type, and physical and chemical variables, including RADIATION-PROTECTIVE AGENTS and RADIATION-SENSITIZING AGENTS.	Radiation Sensitivity,Radiosensitivity,Sensitivity, Radiation,Tolerance, Radiation,Radiation Sensitivities,Radiation Tolerances,Radiosensitivities,Sensitivities, Radiation,Tolerances, Radiation
D002453	Cell Cycle	The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.	Cell Division Cycle,Cell Cycles,Cell Division Cycles,Cycle, Cell,Cycle, Cell Division,Cycles, Cell,Cycles, Cell Division,Division Cycle, Cell,Division Cycles, Cell
D002470	Cell Survival	The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.	Cell Viability,Cell Viabilities,Survival, Cell,Viabilities, Cell,Viability, Cell
D004307	Dose-Response Relationship, Radiation	The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.	Dose Response Relationship, Radiation,Dose-Response Relationships, Radiation,Radiation Dose-Response Relationship,Radiation Dose-Response Relationships,Relationship, Radiation Dose-Response,Relationships, Radiation Dose-Response
D005434	Flow Cytometry	Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.	Cytofluorometry, Flow,Cytometry, Flow,Flow Microfluorimetry,Fluorescence-Activated Cell Sorting,Microfluorometry, Flow,Cell Sorting, Fluorescence-Activated,Cell Sortings, Fluorescence-Activated,Cytofluorometries, Flow,Cytometries, Flow,Flow Cytofluorometries,Flow Cytofluorometry,Flow Cytometries,Flow Microfluorometries,Flow Microfluorometry,Fluorescence Activated Cell Sorting,Fluorescence-Activated Cell Sortings,Microfluorimetry, Flow,Microfluorometries, Flow,Sorting, Fluorescence-Activated Cell,Sortings, Fluorescence-Activated Cell
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014408	Biomarkers, Tumor	Molecular products metabolized and secreted by neoplastic tissue and characterized biochemically in cells or BODY FLUIDS. They are indicators of tumor stage and grade as well as useful for monitoring responses to treatment and predicting recurrence. Many chemical groups are represented including HORMONES; ANTIGENS; amino and NUCLEIC ACIDS; ENZYMES; POLYAMINES; and specific CELL MEMBRANE PROTEINS and LIPIDS.	Biochemical Tumor Marker,Cancer Biomarker,Carcinogen Markers,Markers, Tumor,Metabolite Markers, Neoplasm,Tumor Biomarker,Tumor Marker,Tumor Markers, Biochemical,Tumor Markers, Biological,Biochemical Tumor Markers,Biological Tumor Marker,Biological Tumor Markers,Biomarkers, Cancer,Marker, Biochemical Tumor,Marker, Biologic Tumor,Marker, Biological Tumor,Marker, Neoplasm Metabolite,Marker, Tumor Metabolite,Markers, Biochemical Tumor,Markers, Biological Tumor,Markers, Neoplasm Metabolite,Markers, Tumor Metabolite,Metabolite Markers, Tumor,Neoplasm Metabolite Markers,Tumor Markers, Biologic,Tumor Metabolite Marker,Biologic Tumor Marker,Biologic Tumor Markers,Biomarker, Cancer,Biomarker, Tumor,Cancer Biomarkers,Marker, Tumor,Markers, Biologic Tumor,Markers, Carcinogen,Metabolite Marker, Neoplasm,Metabolite Marker, Tumor,Neoplasm Metabolite Marker,Tumor Biomarkers,Tumor Marker, Biochemical,Tumor Marker, Biologic,Tumor Marker, Biological,Tumor Markers,Tumor Metabolite Markers
D016159	Tumor Suppressor Protein p53	Nuclear phosphoprotein encoded by the p53 gene (GENES, P53) whose normal function is to control CELL PROLIFERATION and APOPTOSIS. A mutant or absent p53 protein has been found in LEUKEMIA; OSTEOSARCOMA; LUNG CANCER; and COLORECTAL CANCER.	p53 Tumor Suppressor Protein,Cellular Tumor Antigen p53,Oncoprotein p53,TP53 Protein,TRP53 Protein,p53 Antigen,pp53 Phosphoprotein,Phosphoprotein, pp53
D016923	Cell Death	The termination of the cell's ability to carry out vital functions such as metabolism, growth, reproduction, responsiveness, and adaptability.	Death, Cell