title: Effect of the Bowman-Birk protease inhibitor on the expression of oncogenes in the irradiated rat colon.
abstract: In this study, we tested the influence of i.p. Bowman-Birk protease inhibitor (BBI) administration on oncogene expression in unirradiated and irradiated rat colonic mucosa. Total cellular RNA was collected from the colonic mucosa, and the levels of c-myc, c-fos, c-Ha-ras, c-EGFR, and c-actin mRNA were examined by standard dot and Northern blot analyses. The data demonstrate that BBI is capable of preventing radiation-induced overexpression of c-myc and c-fos without interfering with the constitutive expression of these 2 genes. It was also determined that BBI did not interfere with either radiation-induced overexpression of c-Ha-ras and c-EGFR or the constitutive expression of c-Ha-ras, c-EGFR, or c-actin. The data demonstrate that the anticarcinogenic BBI selectively inhibits the overexpression of c-myc and c-fos while not affecting crypt cell proliferation. These results suggest that a protease is involved in the pathway for enhanced c-myc and c-fos expression and that protease inhibitors such as BBI can interrupt this pathway.
authors.affiliation: Department of Radiology, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, North Carolina 27157.
authors.forename: W H
authors.initials: WH
authors.lastname: St Clair
authors.forename: D K
authors.initials: DK
authors.lastname: St Clair
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D002455:Cell Division / Q000187:drug effects; D003106:Colon / Q000528:radiation effects* / Q000648:ultrastructure; D066246:ErbB Receptors / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D016259:Genes, myc; D011905:Genes, ras; D016761:Oncogene Proteins v-fos; D009856:Oncogene Proteins, Viral / Q000235:genetics; D009857:Oncogenes / Q000528:radiation effects*; D010179:Pancreas / Q000528:radiation effects; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344; D014358:Trypsin Inhibitor, Bowman-Birk Soybean / Q000494:pharmacology*
chemical_list: D016761:Oncogene Proteins v-fos; D009856:Oncogene Proteins, Viral; D012333:RNA, Messenger; D014358:Trypsin Inhibitor, Bowman-Birk Soybean; D066246:ErbB Receptors