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Ionizing radiation induces a p53-dependent apoptotic mechanism in ARPE-19 cells.
Jpn J Ophthalmol 2004 Mar-Apr; 48(2):106-14JJ

Abstract

PURPOSE

To investigate the molecular mechanisms for cell growth inhibition or apoptosis in human retinal pigment epithelium (RPE) cells after ionizing radiation.

METHODS

Cell survival studies, a TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay, and a caspase-3 immunocytochemical analysis were performed on irradiated ARPE-19 cell cultures at different time periods. Transcriptional levels of p53, p21, Bax, Fas/Fas-L, vascular endothelial growth factor (VEGF), and pigment epithelium-derived growth factor (PEDF) were evaluated by semiquantitative reverse transcriptional polymerase chain reaction. Mutations in the p53 gene were analyzed by DNA sequencing. Protein levels of p53, VEGF, and PEDF were evaluated by Western blot.

RESULTS

Cell viability was inversely related to radiation dose. TUNEL-positive cells were detected 6 h after radiation exposure. Caspase-3 immunocytochemical analysis revealed increased immunoreactivity in the TUNEL-positive cells. Levels of p53, p21, and Bax mRNA were greatest at the 2-h postradiation period. VEGF and PEDF mRNA and protein levels were constant. Protein levels of p53 were increased at the 4- and 6-h postradiation period.

CONCLUSIONS

Ionizing radiation induces apoptosis in normal proliferating RPE cells through p53 activation, without affecting expression of VEGF or PEDF. We documented a molecular basis for explaining the decrease in effectiveness of radiation therapy, particularly for age-related macular degeneration. In the clinical setting, selection of appropriate radiation therapy methods and the doses for specific diseases need careful evaluation.

Authors+Show Affiliations

Department of Organ Therapeutics, Kobe University Graduate School of Medicine, Kobe, Japan. jiangyanlin00@hotmail.comNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15064971

Citation

Jiang, Yan Lin, et al. "Ionizing Radiation Induces a P53-dependent Apoptotic Mechanism in ARPE-19 Cells." Japanese Journal of Ophthalmology, vol. 48, no. 2, 2004, pp. 106-14.
Jiang YL, Escaño MF, Sasaki R, et al. Ionizing radiation induces a p53-dependent apoptotic mechanism in ARPE-19 cells. Jpn J Ophthalmol. 2004;48(2):106-14.
Jiang, Y. L., Escaño, M. F., Sasaki, R., Fujii, S., Kusuhara, S., Matsumoto, A., ... Negi, A. (2004). Ionizing radiation induces a p53-dependent apoptotic mechanism in ARPE-19 cells. Japanese Journal of Ophthalmology, 48(2), pp. 106-14.
Jiang YL, et al. Ionizing Radiation Induces a P53-dependent Apoptotic Mechanism in ARPE-19 Cells. Jpn J Ophthalmol. 2004;48(2):106-14. PubMed PMID: 15064971.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Ionizing radiation induces a p53-dependent apoptotic mechanism in ARPE-19 cells. AU - Jiang,Yan Lin, AU - Escaño,Michael F T, AU - Sasaki,Ryohei, AU - Fujii,Shigeki, AU - Kusuhara,Sentaro, AU - Matsumoto,Akira, AU - Sugimura,Kazuro, AU - Negi,Akira, PY - 2003/04/21/received PY - 2003/11/28/accepted PY - 2004/4/6/pubmed PY - 2004/5/14/medline PY - 2004/4/6/entrez SP - 106 EP - 14 JF - Japanese journal of ophthalmology JO - Jpn. J. Ophthalmol. VL - 48 IS - 2 N2 - PURPOSE: To investigate the molecular mechanisms for cell growth inhibition or apoptosis in human retinal pigment epithelium (RPE) cells after ionizing radiation. METHODS: Cell survival studies, a TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay, and a caspase-3 immunocytochemical analysis were performed on irradiated ARPE-19 cell cultures at different time periods. Transcriptional levels of p53, p21, Bax, Fas/Fas-L, vascular endothelial growth factor (VEGF), and pigment epithelium-derived growth factor (PEDF) were evaluated by semiquantitative reverse transcriptional polymerase chain reaction. Mutations in the p53 gene were analyzed by DNA sequencing. Protein levels of p53, VEGF, and PEDF were evaluated by Western blot. RESULTS: Cell viability was inversely related to radiation dose. TUNEL-positive cells were detected 6 h after radiation exposure. Caspase-3 immunocytochemical analysis revealed increased immunoreactivity in the TUNEL-positive cells. Levels of p53, p21, and Bax mRNA were greatest at the 2-h postradiation period. VEGF and PEDF mRNA and protein levels were constant. Protein levels of p53 were increased at the 4- and 6-h postradiation period. CONCLUSIONS: Ionizing radiation induces apoptosis in normal proliferating RPE cells through p53 activation, without affecting expression of VEGF or PEDF. We documented a molecular basis for explaining the decrease in effectiveness of radiation therapy, particularly for age-related macular degeneration. In the clinical setting, selection of appropriate radiation therapy methods and the doses for specific diseases need careful evaluation. SN - 0021-5155 UR - https://www.unboundmedicine.com/medline/citation/15064971/Ionizing_radiation_induces_a_p53_dependent_apoptotic_mechanism_in_ARPE_19_cells_ L2 - https://dx.doi.org/10.1007/s10384-003-0043-x DB - PRIME DP - Unbound Medicine ER -