Activation of nuclear factor kappa B in human lymphoblastoid cells by low-dose ionizing radiation.
Nuclear factor kappa B (NF-kappa B) is a pleiotropic transcription factor which is involved in the transcriptional regulation of several specific genes. Recent reports demonstrated that ionizing radiation in the dose range of 2-50 Gy results in expression of NF-kappa B in human KG-1 myeloid leukemia cells and human B-lymphocyte precursor cells; the precise mechanism involved and the significance are not yet known. The present report demonstrates that even lower doses of ionizing radiation, 0.25-2.0 Gy, are capable of inducing expression of NF-kappa B in EBV-transformed 244B human lymphoblastoid cells. These results are in a dose range where the viability of the cells remains very high. After exposure to 137Cs gamma rays at a dose rate of 1.17 Gy/min, a maximum in expression of NF-kappa B was seen at 8 h after a 0.5-Gy exposure. Time-course studies revealed a biphasic time-dependent expression after 0.5-, 1- and 2-Gy exposures. However, for each time examined, the expression of NF-kappa B was maximum after the 0.5-Gy exposure. The expression of the p50 and p65 NF-kappa B subunits was also shown to be regulated differentially after exposures to 1.0 and 2.0 Gy.
Prasad
A V
AV
Department of Radiology, University of Texas Health Science Center, San Antonio 78284-7800.
Mohan
N
N
Chandrasekar
B
B
Meltz
M L
ML
D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006801:Humans; D066298:In Vitro Techniques; D008214:Lymphocytes / Q000378:metabolism / Q000528:radiation effects*; D046911:Macromolecular Substances; D016328:NF-kappa B / Q000378:metabolism*; D013997:Time Factors
D046911:Macromolecular Substances; D016328:NF-kappa B