The effects of the Bowman-Birk protease inhibitor on c-myc expression and cell proliferation in the unirradiated and irradiated mouse colon.
The levels of c-myc RNA and crypt cell proliferation were monitored in the mouse colonic mucosa following X-irradiation with and without oral administration of the Bowman-Birk protease inhibitor (BBI). Mice were divided into 4 groups and treated as follows: (A) daily gavage with water; (B) daily gavage with BBI; (C) daily gavage with water and 12 Gy of abdominal irradiation 1 day after the first gavage; (D) daily gavage with BBI and 12 Gy of abdominal irradiation 1 day after the first gavage. Samples were collected at various times after X-irradiation and ascending colon samples were taken for crypt cell proliferation analysis. The mucosa was removed from the remaining sample and total cellular RNA was isolated. The levels of c-myc mRNA underwent a time-dependent change following X-irradiation. Expression of the c-myc gene was unchanged at 1 day and 3 weeks after irradiation, but was markedly elevated at 1 week after X-irradiation. BBI was found to suppress the radiation induced elevation of c-myc mRNA, while having no effect on the rate of crypt cell proliferation or body weight of the mice.
Department of Radiology, Bowman Gray School of Medicine, Winston-Salem, NC 27104.
W H
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St Clair
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Billings
A R
AR
Kennedy
D000818:Animals; D015152:Blotting, Northern; D001835:Body Weight / Q000528:radiation effects; D002455:Cell Division / Q000187:drug effects* / Q000528:radiation effects; D003106:Colon / Q000166:cytology; D015870:Gene Expression / Q000187:drug effects / Q000528:radiation effects; D007413:Intestinal Mucosa / Q000166:cytology*; D008297:Male; D051379:Mice; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger / Q000235:genetics; D014358:Trypsin Inhibitor, Bowman-Birk Soybean / Q000494:pharmacology*; D014361:Trypsin Inhibitors / Q000494:pharmacology*; D014965:X-Rays
D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D014358:Trypsin Inhibitor, Bowman-Birk Soybean; D014361:Trypsin Inhibitors