skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Threshold Level of p53 Required for the Induction of Apoptosis in X-Irradiated MOLT-4 Cells

Abstract

Purpose: To determine the threshold level for the initiation of apoptosis by studying the quantitative aspect of p53 response to DNA damage in individual cells, to better understand the process in X-ray-induced p53-dependent apoptosis. Methods and Materials: Time-sequential changes in p53 protein level were obtained for X-irradiated MOLT-4 cells using flow cytometry and analyzed. Results: The changes in the cellular frequency distribution pattern of p53 content could be divided into two parts at a certain p53 level. The p53 vs. side-scatter in flow cytometry showed the sequential changes of p53 increase followed by an increase in cell death. On the basis of these results we determined a threshold level of p53 for the initiation of apoptosis. The level was estimated to be (1.08 {+-} 0.05) x 10{sup 5} molecules per cell, which was approximately threefold higher than the mean content of control cells. The minimum times for p53 level to reach this threshold level were independent of X-ray dose and 1.4-1.6 h. The times for the signal transduction from the p53 accumulation to disruption of the mitochondrial membrane potential, caspase-3 activation, and cell death were 1.6, 2.1, and 2.8 h, respectively. Conclusions: The threshold level of p53 for the initiationmore » of apoptosis and the time sequence in the course of apoptotic events were determined in X-irradiated MOLT-4 cells.« less

Authors:
 [1];  [1];  [1]
  1. Department of Laboratory Animal Science, Tokyo Metropolitan Institute of Medical Science, Tokyo (Japan)
Publication Date:
OSTI Identifier:
20951719
Resource Type:
Journal Article
Journal Name:
International Journal of Radiation Oncology, Biology and Physics
Additional Journal Information:
Journal Volume: 68; Journal Issue: 3; Other Information: DOI: 10.1016/j.ijrobp.2007.03.007; PII: S0360-3016(07)00386-0; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0360-3016
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; APOPTOSIS; DNA DAMAGES; IRRADIATION; MITOCHONDRIA; PROTEINS; RADIATION DOSES; X RADIATION

Citation Formats

Nakano, Hisako, Yonekawa, Hiromichi, Shinohara, Kunio, and Japan Synchrotron Radiation Research Institute, Hyogo. Threshold Level of p53 Required for the Induction of Apoptosis in X-Irradiated MOLT-4 Cells. United States: N. p., 2007. Web. doi:10.1016/j.ijrobp.2007.03.007.
Nakano, Hisako, Yonekawa, Hiromichi, Shinohara, Kunio, & Japan Synchrotron Radiation Research Institute, Hyogo. Threshold Level of p53 Required for the Induction of Apoptosis in X-Irradiated MOLT-4 Cells. United States. https://doi.org/10.1016/j.ijrobp.2007.03.007
Nakano, Hisako, Yonekawa, Hiromichi, Shinohara, Kunio, and Japan Synchrotron Radiation Research Institute, Hyogo. 2007. "Threshold Level of p53 Required for the Induction of Apoptosis in X-Irradiated MOLT-4 Cells". United States. https://doi.org/10.1016/j.ijrobp.2007.03.007.
@article{osti_20951719,
title = {Threshold Level of p53 Required for the Induction of Apoptosis in X-Irradiated MOLT-4 Cells},
author = {Nakano, Hisako and Yonekawa, Hiromichi and Shinohara, Kunio and Japan Synchrotron Radiation Research Institute, Hyogo},
abstractNote = {Purpose: To determine the threshold level for the initiation of apoptosis by studying the quantitative aspect of p53 response to DNA damage in individual cells, to better understand the process in X-ray-induced p53-dependent apoptosis. Methods and Materials: Time-sequential changes in p53 protein level were obtained for X-irradiated MOLT-4 cells using flow cytometry and analyzed. Results: The changes in the cellular frequency distribution pattern of p53 content could be divided into two parts at a certain p53 level. The p53 vs. side-scatter in flow cytometry showed the sequential changes of p53 increase followed by an increase in cell death. On the basis of these results we determined a threshold level of p53 for the initiation of apoptosis. The level was estimated to be (1.08 {+-} 0.05) x 10{sup 5} molecules per cell, which was approximately threefold higher than the mean content of control cells. The minimum times for p53 level to reach this threshold level were independent of X-ray dose and 1.4-1.6 h. The times for the signal transduction from the p53 accumulation to disruption of the mitochondrial membrane potential, caspase-3 activation, and cell death were 1.6, 2.1, and 2.8 h, respectively. Conclusions: The threshold level of p53 for the initiation of apoptosis and the time sequence in the course of apoptotic events were determined in X-irradiated MOLT-4 cells.},
doi = {10.1016/j.ijrobp.2007.03.007},
url = {https://www.osti.gov/biblio/20951719}, journal = {International Journal of Radiation Oncology, Biology and Physics},
issn = {0360-3016},
number = 3,
volume = 68,
place = {United States},
year = {Sun Jul 01 00:00:00 EDT 2007},
month = {Sun Jul 01 00:00:00 EDT 2007}
}