X-ray-mediated reduction in basic fibroblast growth factor expression in primary rat astrocyte cultures.
Injury of the normal central nervous system is a major concern in the radiotherapy of brain tumors, but the pathogenesis of injury remains poorly understood. Modulation of the production of growth factors is associated with ischemia and traumatic injury in the central nervous system. Ionizing radiation has been shown to induce basic fibroblast growth factor in endothelial cells and in cells of a human breast carcinoma cell line. The inducibility of basic fibroblast growth factor after irradiation and its potential role in the recovery response of the central nervous system led us to investigate the effects of radiation on the expression of this growth factor in primary cultures of normal rat type 1 astrocytes. Astrocyte monolayers were exposed to ionizing radiation (1 to 10 Gy). Northern blot analysis revealed that doses of 2 to 10 Gy markedly reduced the expression of basic fibroblast growth factor as early as 1 h after irradiation, and that it remained below levels in unirradiated cells for at least 24 h. The effect was not associated with astrocyte cytotoxicity, and it appears to have some specificity for basic fibroblast growth factor since the levels of mRNA coding for ciliary neurotrophic factor and glial fibrillary acidic protein were not affected.
Noel
F
F
Department of Experimental Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston 77030, USA.
Ijichi
A
A
Chen
J J
JJ
Gumin
G J
GJ
Tofilon
P J
PJ
D000591:Amino Acid Isomerases / Q000096:biosynthesis; D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D001943:Breast Neoplasms; D002352:Carrier Proteins / Q000096:biosynthesis; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000378:metabolism; D020934:Ciliary Neurotrophic Factor; D004622:Embryo, Mammalian; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000096:biosynthesis*; D005904:Glial Fibrillary Acidic Protein / Q000096:biosynthesis; D006801:Humans; D007700:Kinetics; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D019696:Peptidylprolyl Isomerase; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects / Q000528:radiation effects*; D014407:Tumor Cells, Cultured
D002352:Carrier Proteins; D020934:Ciliary Neurotrophic Factor; D005904:Glial Fibrillary Acidic Protein; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D016222:Fibroblast Growth Factor 2; D000591:Amino Acid Isomerases; D019696:Peptidylprolyl Isomerase; D013755:Tetradecanoylphorbol Acetate