Carcinogenesis, Vol. 23, No. 9, 1447-1454,
September 2002
© 2002 Oxford University Press
MOLECULAR EPIDEMIOLOGY AND CANCER PREVENTION |
Altered expression of c-myc, p16 and p27 in rat colon tumors and its reversal by short-term treatment with chemopreventive agents
1 Department of Pathology, HEB, Rm 202, Medical College of Ohio, 3055 Arlington Ave., Toledo, OH 43614-5806, USA and
2 Chemopreventive Agent Development Research Group, Division of Cancer Prevention, National Cancer Institute, Bethesda, MD 20892, USA
Modulation of gene expression in tumors has the potential of being a surrogate end-point biomarker for chemoprevention. Thus, we determined the modulation by chemopreventive agents of the protein and mRNA expression of genes in rat colon tumors. Male F344 rats were administered three weekly injections of 15 mg/kg azoxymethane. Forty-seven weeks later, they received aspirin (600), calcium chloride (50 000), 2-(carboxyphenyl) retinamide (2-CPR, 315),
-difluoromethylornithine (DFMO, 3000), piroxicam (200), quercetin (33 600), 9-cis retinoic acid (9-cis RA, 30), rutin (3000), or sulindac (280) in their diet at the indicated mg/kg concentration for 7 days and were then killed. In colon tumors relative to the mucosa, the protein and mRNA levels of c-myc were increased, while the levels of p16 and p27 were decreased. Calcium chloride, DFMO, piroxicam and sulindac administered for 7 days decreased the mitotic index and reduced the protein and mRNA levels of c-myc in colon tumors. Calcium chloride, DFMO and piroxicam increased the protein and mRNA levels of p16 and along with sulindac increased the protein level of p27, but not its mRNA. The other agents failed to modulate both the mitotic index and the expression of the genes. The ability of the chemopreventive agents to prevent colon tumors was determined. Male F344 rats were administered three weekly injections of 15 mg/kg azoxymethane and 8 weeks later they were administered aspirin, 2-CPR, DFMO, piroxicam, 9-cis RA and rutin in their diet. The rats were killed 26 weeks after they started to receive the chemopreventive agents. The multiplicity of colon tumors was reduced by DFMO and piroxicam, increased by rutin and not affected by the other agents. Hence, agents that prevented colon cancer decreased the mitotic index and altered the expression of c-myc, p16 and p27 suggesting that modulation in the expression of these genes are potential biomarkers for chemopreventive activity.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
T. P. Ong, R. Heidor, A. de Conti, M. L. Z. Dagli, and F. S. Moreno Farnesol and geraniol chemopreventive activities during the initial phases of hepatocarcinogenesis involve similar actions on cell proliferation and DNA damage, but distinct actions on apoptosis, plasma cholesterol and HMGCoA reductase Carcinogenesis, June 1, 2006; 27(6): 1194 - 1203. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Yu, D. A. Quinn, H. G. Garg, and C. A. Hales Cyclin-Dependent Kinase Inhibitor p27Kip1, But Not p21WAF1/Cip1, Is Required for Inhibition of Hypoxia-Induced Pulmonary Hypertension and Remodeling by Heparin in Mice Circ. Res., October 28, 2005; 97(9): 937 - 945. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. R. Volate, D. M. Davenport, S. J. Muga, and M. J. Wargovich Modulation of aberrant crypt foci and apoptosis by dietary herbal supplements (quercetin, curcumin, silymarin, ginseng and rutin) Carcinogenesis, August 1, 2005; 26(8): 1450 - 1456. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. de Moura Espindola, R. P. Mazzantini, T. P. Ong, A. de Conti, R. Heidor, and F. S. Moreno Geranylgeraniol and {beta}-ionone inhibit hepatic preneoplastic lesions, cell proliferation, total plasma cholesterol and DNA damage during the initial phases of hepatocarcinogenesis, but only the former inhibits NF-{kappa}B activation Carcinogenesis, June 1, 2005; 26(6): 1091 - 1099. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. A. Pereira, L. Tao, W. Wang, Y. Li, A. Umar, V. E. Steele, and R. A. Lubet Modulation by celecoxib and difluoromethylornithine of the methylation of DNA and the estrogen receptor-{alpha} gene in rat colon tumors Carcinogenesis, October 1, 2004; 25(10): 1917 - 1923. [Abstract] [Full Text] [PDF] |
||||

