Low energy proton beam induces efficient cell killing in A549 lung adenocarcinoma cells.
The aim of the current study was to determine the signaling differences between gamma- and proton beam-irradiations. A549 lung adenocarcinoma cells were irradiated with 2 Gy proton beam or gamma-radiation. Proton beam was found to be more cytotoxic than gamma-radiation. Proton beam-irradiated cells showed phosphorylation of H2AX, ATM, Chk2, and p53. The mechanism of excessive cell killing in proton beam-irradiated cells was found to be upregulation of Bax and downregulation of Bcl-2. The noteworthy finding of this study is the biphasic activation of the sensor proteins, ATM, and DNA-PK and no activation of ATR by proton irradiation.
Ghosh
Somnath
S
Radiation Biology and Health Sciences Division, Trombay, Mumbai, India.
Bhat
Nagesh N
NN
Santra
S
S
Thomas
R G
RG
Gupta
S K
SK
Choudhury
R K
RK
Krishna
Malini
M
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D017209:Apoptosis / Q000235:genetics / Q000528:radiation effects*; D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins / Q000378:metabolism; D016923:Cell Death / Q000528:radiation effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000528:radiation effects; D064447:Checkpoint Kinase 2; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000378:metabolism; D005720:Gamma Rays; D015972:Gene Expression Regulation, Neoplastic / Q000528:radiation effects; D006657:Histones / Q000378:metabolism; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011522:Protons; D013997:Time Factors; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000378:metabolism
C494826:BAX protein, human; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; C468783:H2AX protein, human; D006657:Histones; D019253:Proto-Oncogene Proteins c-bcl-2; D011522:Protons; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D051028:bcl-2-Associated X Protein; D064447:Checkpoint Kinase 2; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C578634:CHEK2 protein, human; D017346:Protein Serine-Threonine Kinases