PURPOSE: The effect of pravastatin, an inhibitor of ras p21 isoprenylation, on the gross type of colon tumors induced by azoxymethane was investigated in Wistar rats. METHODS: Rats received ten weekly subcutaneous injections of 7.4 mg/kg body weight of azoxymethane and intraperitoneal injections of 10 or 20 mg/kg body weight of pravastatin every other day until the end of the experiment at Week 45. RESULTS: Administration of pravastatin at both dosages had no significant effect on the incidence of colon tumors but significantly increased the incidence of rats with adenomas only. In contrast to the elevated adenomas in control rats, flat adenomas were significantly more prevalent in rats given pravastatin. Pravastatin at both doses significantly decreased the labeling index, but not the apoptotic index, of elevated adenomas, whereas it significantly decreased the labeling index but increased the apoptotic index of flat adenomas. Administration of pravastatin at both dosages also significantly decreased the amounts of membrane-associated ras p21 in colon tumors. CONCLUSIONS: These findings suggest that the ras oncogene may be closely related to the development of adenocarcinomas from adenomas and the development of elevated or polypoid tumors of the colon.
PURPOSE: The effect of pravastatin, an inhibitor of ras p21 isoprenylation, on the gross type of colon tumors induced by azoxymethane was investigated in Wistar rats. METHODS:Rats received ten weekly subcutaneous injections of 7.4 mg/kg body weight of azoxymethane and intraperitoneal injections of 10 or 20 mg/kg body weight of pravastatin every other day until the end of the experiment at Week 45. RESULTS: Administration of pravastatin at both dosages had no significant effect on the incidence of colon tumors but significantly increased the incidence of rats with adenomas only. In contrast to the elevated adenomas in control rats, flat adenomas were significantly more prevalent in rats given pravastatin. Pravastatin at both doses significantly decreased the labeling index, but not the apoptotic index, of elevated adenomas, whereas it significantly decreased the labeling index but increased the apoptotic index of flat adenomas. Administration of pravastatin at both dosages also significantly decreased the amounts of membrane-associated ras p21 in colon tumors. CONCLUSIONS: These findings suggest that the ras oncogene may be closely related to the development of adenocarcinomas from adenomas and the development of elevated or polypoid tumors of the colon.
Authors: Dominique Beaudry; Kenneth E Stone; Suzanne Wetherold; John Hemphill; Dat Do; John McClish; Robert Chilton Journal: Curr Atheroscler Rep Date: 2007-01 Impact factor: 5.113
Authors: Keith R Solomon; Kristine Pelton; Kelly Boucher; Jinsoo Joo; Christopher Tully; David Zurakowski; Carl P Schaffner; Jayoung Kim; Michael R Freeman Journal: Am J Pathol Date: 2009-01-29 Impact factor: 4.307