Mechanisms of apoptosis induction and cell cycle regulation in irradiated leukemia U937 cells and enhancement by arsenic trioxide.
Apoptosis is a common mode of cell death after exposure of tumor cells to radiation and/or chemotherapy. The factors that determine the rate of induction of apoptosis are generally related to the functioning of cell cycle checkpoints. In the present study, we investigated the involvement of several genes in cell cycle redistribution and induction of apoptosis in U937 cells after low and high doses of radiation. Activation of CDC2 was observed after both low and high doses of radiation in U937 cells that underwent apoptosis. Expression of CDK2, CDC2 and cyclin A was induced rapidly in the process of radiation-induced apoptosis. In addition, we investigated the use of a clinically relevant dose of radiation to promote As2O3-induced apoptosis in U937 cells. We found that combining radiation and As2O3 may be a new and more effective means of cancer treatment.
Institute of Basic Medical Sciences, National Cheng Kung University, Medical College, Tainan, Taiwan.
Sheng-Yow
SY
Ho
Po-Chang
PC
Huang
How-Ran
HR
Guo
Wen-Huei
WH
Chang
Rong-Jane
RJ
Chen
Bai-Lu
BL
Wei
Wei-Jr
WJ
Wu
Chein
C
Tai
Ying-Jan
YJ
Wang
D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000008:administration & dosage*; D002453:Cell Cycle / Q000187:drug effects* / Q000528:radiation effects*; D018797:Cell Cycle Proteins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D010087:Oxides / Q000008:administration & dosage*; D011829:Radiation Dosage; D011836:Radiation Tolerance / Q000187:drug effects*; D020298:U937 Cells
D051017:Apoptosis Regulatory Proteins; D001152:Arsenicals; D018797:Cell Cycle Proteins; D010087:Oxides; D000077237:Arsenic Trioxide