Cell cycle and apoptosis alteration of human hepatocarcinoma cells by subclinical-dose 12C6+-beam irradiation.
OBJECTIVE
The purpose of this study is to investigate the effect of subclinical-dose C-beam irradiation on cell cycle and cell apoptosis in hepatocarcinoma cells.


METHODS
The HepG2 cells were exposed to 0-2.0 Gy of either the C beam or a gamma-ray. Cell survival was detected by clonogenic assay. Cell cycle was determined by flow-cytometry analysis. The apoptosis was monitored by fluorescence microscope with DAPI staining. p53 and p21 expression were detected by Western blot.


RESULTS
The G0/G1 cells in the irradiated groups were significantly more than those in the control (P<0.05). The C-ion irradiation had a greater effect on the cell cycle of HepG2 cells (including promoting G1-phase and G2-phase arrest) than gamma-ray irradiation. The apoptotic cells induced by C beam were significantly more numerous than those induced by gamma-ray (P<0.05). The carbon ions had a stronger effect on p53 and p21 expression than the gamma-ray irradiation. The survival fractions for cells irradiated by C beam were significantly smaller than those irradiated by gamma-ray (P<0.05).


CONCLUSIONS
The subclinical-dose C-beam irradiation significantly suppresses HepG2 cells through cell-cycle arrests and cell apoptosis in contrast to same-dose gamma-ray irradiation.
Liu
Bing
B
Institute of Modern Physics, Chinese Academy of Sciences, Beijing 100039, China. liub626@126.com
Zhang
Hong
H
Xie
Yi
Y
Hao
Jifang
J
Duan
Xin
X
Zhou
Qingming
Q
Qiu
Rong
R
Zhou
Guangming
G
D017209:Apoptosis / Q000528:radiation effects*; D015153:Blotting, Western; D002244:Carbon; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology*; D002453:Cell Cycle / Q000528:radiation effects*; D002470:Cell Survival / Q000528:radiation effects; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D020450:Heavy Ions; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology*; D009363:Neoplasm Proteins / Q000378:metabolism; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D009363:Neoplasm Proteins; D016159:Tumor Suppressor Protein p53; D002244:Carbon