Increased expression of prohormone convertase-2 in the irradiated rat brain.
Changes in gene expression have been suggested to play a role in radiotherapy-induced central nervous system (CNS) injury. To begin to identify radiation-inducible genes in the CNS, we have applied the differential display of reverse transcription-polymerase chain reaction products to RNA extracted from the brain of adult rats. RNA was isolated from a rat brain 6 h after whole-body exposure to 10 Gy and compared with RNA from unirradiated brain. A cDNA band was consistently observed at about 600 bp in samples from the irradiated rat but not from unirradiated (control) rat. Amplification and sequencing of the cDNA revealed that it corresponded to the prohormone convertase-2 (PC2) gene, which is involved in the processing of inert prohormones and neuropeptides to their bioactive forms. Enhanced PC2 expression was detected after irradiation of neuronal cultures but not in cultures of astrocytes, suggesting that the cell type in the CNS responsible for the PC2 induction after in vivo irradiation is the neuron. These results indicate that radiation induces the expression of a neuronal enzyme that is critical to the activation of a number of prohormones and neuropeptides, which may influence the radioresponse of the CNS.
Noel
F
F
Departments of Experimental Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
Gumin
G J
GJ
Raju
U
U
Tofilon
P J
PJ
D000818:Animals; D001921:Brain / Q000201:enzymology* / Q000528:radiation effects*; D004790:Enzyme Induction; D005720:Gamma Rays; D045706:Proprotein Convertase 2; D051381:Rats; D017207:Rats, Sprague-Dawley; D013381:Subtilisins / Q000096:biosynthesis*; D014916:Whole-Body Irradiation
D013381:Subtilisins; D045706:Proprotein Convertase 2