Hdm2 and nitric oxide radicals contribute to the p53-dependent radioadaptive response
Abstract
The aim of this work was to characterize the radioadaptive response at the molecular level. We used wild-type (wt) p53 and mutated (m) p53-containing cells derived from the human lung cancer H1299 cell line, which is p53-null. Cellular radiation sensitivities were determined with a colony-forming assay. The accumulations of p53, the human homolog of endogenous murine double minute 2 (Hdm2), and inducible nitric oxide synthase were analyzed with Western blotting. Quantification of chromosomal aberrations was estimated by scoring dicentrics per cell. In wtp53 cells, it was demonstrated that the lack of p53 accumulation was coupled with the activation of Hdm2 after low-dose irradiation (0.02 Gy). Although NO radicals were only minimally induced in wtp53 cells irradiated with a challenging irradiation (6 Gy) alone, NO radicals were seen to increase about two- to fourfold after challenging irradiation subsequent to a priming irradiation (0.02 Gy). Under similar irradiation conditions with a priming and challenging irradiation in wtp53 cells, induction of radioresistance and a depression of chromosomal aberrations were observed only in the absence of 5, 5'-(2, 5-Furanidiyl)bis-2-thiophenemethanol (RITA) or Nutlin-3 (p53-Hdm2 interact...Continue Reading
References
Citations
Related Concepts
Related Feeds
Bioinformatics in Biomedicine
Bioinformatics in biomedicine incorporates computer science, biology, chemistry, medicine, mathematics and statistics. Discover the latest research on bioinformatics in biomedicine here.
Antianginal Drugs: Mechanisms of Action
Antianginal drugs, including nitrates, beta-blockers, and calcium channel blockers, are used in the treatment of angina pectoris. Here is the latest research on their use and their mechanism of action.
Apoptosis
Apoptosis is a specific process that leads to programmed cell death through the activation of an evolutionary conserved intracellular pathway leading to pathognomic cellular changes distinct from cellular necrosis