CYP450 1A1 and p53 expression and DNA adduct formation in the liver of rats treated with a single dose of aflatoxins

아플라톡신을 간회 투여한 랫드의 간에서 CYP450 1A1, p53의 발현과 DNA adduct의 형성

  • Lee, Beom Jun (College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University) ;
  • Lee, Sook Jin (College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University) ;
  • Kim, Tae Myoung (College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University) ;
  • Kim, Dae Joong (College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University) ;
  • Nam, Sang Yoon (College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University) ;
  • Hyun, Sang Hwan (College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University) ;
  • Kang, Jong Koo (College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University) ;
  • Hong, Jin Tae (College of Pharmacy and Research Institute of Veterinary Medicine, Chungbuk National University) ;
  • Kim, Cheul Kyu (National Institute of Toxicological Research, Korea FDA) ;
  • Yun, Young Won (College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University)
  • 이범준 (충북대학교 수의과대학 및 동물의학연구소) ;
  • 이숙진 (충북대학교 수의과대학 및 동물의학연구소) ;
  • 김태명 (충북대학교 수의과대학 및 동물의학연구소) ;
  • 김대중 (충북대학교 수의과대학 및 동물의학연구소) ;
  • 남상윤 (충북대학교 수의과대학 및 동물의학연구소) ;
  • 현상환 (충북대학교 수의과대학 및 동물의학연구소) ;
  • 강종구 (충북대학교 수의과대학 및 동물의학연구소) ;
  • 홍진태 (충북대학교 약학대학 및 동물의학연구소) ;
  • 김철규 (국립독성연구원 독성연구부) ;
  • 윤영원 (충북대학교 수의과대학 및 동물의학연구소)
  • Accepted : 2004.11.20
  • Published : 2004.12.30

Abstract

Aflatoxins are produced mainly by Aspergillus flavus and Aspergillus parasiticus that grow in improperly stored cereals. Aflatoxin B1 ($AFB_1$) is a potent hepatocarcinogen in a variety of experimental animals including human beings. In spite of a high attention to the hepatocarcinogenecity of $AFB_1$, the relative toxicity of aflatoxins ($AFB_2$ and $AFG_1$) is not fully clarified. Sprague-Dawley male rats were orally administered with $AFB_1$, $AFB_2$, and $AFG_1$ at the dose of 250 ${\mu}g/kg$ (additionally including a dose of $1250{\mu}g/kg $ for $AFB_1$) body weight. Animals were then killed at 12, 24 or 48 hrs following aflatoxin exposure. Subsequently the immunohistochemical examination of p53, cytochrome p450 1A1 (CYP450 1A1), and glutathione-S-transferase placental form (GST-P) were performed. The level of the 8-OxodG in the liver was determined. Expressions of CYP450 1A1 and p53 were high in the liver of rats through 48 hrs after treatment of $AFB_1$ at the single dose of $250{\mu}g/kg $. This pattern was more clear as increasing doses. The treatment of $AFB_2$ and $AFG_1$ did not affect the expression of CYP450 1A1 but it caused weak expression of p53. The activity of GST were not found in the liver of rats treated with aflatoxins. The formation of 8-OxodG by $AFB_1$ increased in a dose-dependent manner up to 24 hrs after a single treatment of $AFB_1$ thereafter decreased to the level of control. The treatment of $AFB_2$ and $AFG_1$ did not affect the levels of 8-OxodG in the liver of rats with increasing time. These results in the present study indicate that $AFB_1$ among aflatoxins with low comparable levels is the most toxic as determined by early biomarkers such as CYP450 1A1, p53, GST-P, and 8-OxodG.

Keywords

References

  1. Allameh, A., Farahani, M. and Zarghi, A. Kinetic studies of aflatoxin B1-glutathione conjugate formation in liver and kidney of adult and weanling rats. Mech. Ageing Dev. 2000, 115, 73-83
  2. Busby, W. F., Jr. and Wogan, G. N. Chemical Carcinogens (Searle, C. ed) pp. 945-1136, Am. Chem. Soc., Washington, DC, 1984
  3. Chao, H. K., Tsai, T. F., Lin, C. S. and Su, T. S. Evidence that Mutational Activation of the ras genes may not be involved in Aflatoxin B1-induced Human Hepatocarcinogenesis, Based on Sequence Analysis of the ras and p53 genes. Mol. Carcinog. 1999, 26, 69-73
  4. Chen, S. Y., Chen, C. J., Tsai, W. Y., Ahsan, H., Liu, T. Y., Lin, J. T. and Santella, R. M. Associations of plasma aflatoxin B1-albumin adduct level with plasma selenium level and genetic polymorphisms of glutathione S-transferase $M_1$ and $T_1$. Nutr. Cancer. 2000, 38, 179-185
  5. Croy, R. G. and Wogan, G. N. Temporal patterns of covalent DNA adducts in rat liver after single and multiple doses of aflatoxin B1. Cancer Res. 1981, 41, 197-203
  6. Croy, R. G., Essigmann, J. M., Reinhoil, V. N. and Wogan, G. N. Identification of the principal aflatoxin B1-DNA adduct formed in vivo in rat liver. Proc. Natl. Acad. Sci. USA. 1978, 75, 1745-1749
  7. Donnelly, P. J. and Massey, T. E. Ki-ras Activation in Lung Cells Isolated from AC3F1 (A/J×C3H/HeJ) Mice After Treatment With Aflatoxin B1. Mol. Carcinog. 1999, 26, 62-67
  8. Gallagher, E. P., Kunze, K. L., Stapleton, P. L. and Eaton, D. L. The kinetics of Aflatoxin B1 oxidation by human cDNA-expressed and human liver microsomal cytochromes P450 1A2 and 3A4. Toxicol. Appl. Pharmacol. 1996, 141, 595-606
  9. Guengerich, F. P., Johnson, W. W., Ueng, Y. F., Yamazaki, H. and Shimada, T. Involvement of cytochrome P450, glutathione S-transferase, and epoxide hydrolase in the metabolism of aflatoxin B1 and relevance to risk of human liver cancer. Environ. Health Perspect. 1996, 104, 557-562
  10. Hall, A. J. and Wild, C. P. Epidemiology of aflatoxin related disease. In The Toxicology of Aflatoxins. Human Health, Veterinary, and Agricultural Significance. p. 233, Academic Press, New York, 1994
  11. Kasai, H. Analysis of a form of oxidative DNA damage, 8-hydorxy-2'-deoxyguanosine, as a marker of cellular oxidative stress during carcinogenesis. Mutat. Res. 1997, 387, 147-163
  12. Lin, J. K., Miller, J. A. and Miller, E. C. 2,3-Dihydro-2-(guan-7-yl)-3-hydroxy-aflatoxin B1, a major acid hydrolysis product of aflatoxin B1-DNA or-ribosomal RNA adducts formed in hepatic microsome-mediated reactions in rat liver in vivo. Cancer Res. 1977, 37, 4430-4438
  13. McMahon, G., Hanson, L., Lee, J. J. and Wogan, G. N. Identification of an activated c-Ki-ras oncogene in rat liver tumors induced by aflatoxin B1. Proc. Natl. Acad. Sci. USA. 1986, 83, 9418-9422
  14. Otteneder, M. and Lutz, W. K. Correlation of DNA adduct levels with tumor incidence: carcinogenic potency of DNA adducts. Mutat. Res. 1999, 424, 237-247
  15. Peers, F., Bosch, X., Kaldor J., Linsell, A. and Pluijmen, M. Aflatoxin exposure, hepatitis B virus infection and liver cancer in Swaziland, Int. J. Cancer. 1987, 39, 545-553
  16. Riley, J., Mandel, H. G., Sinha, S., Judah, D. J. and Neal, G. E. In vitro activation of the human Ha-ras proto-oncogene by aflatoxin B1. Carcinogenesis. 1997, 18, 905-910
  17. Shen, H. M., Ong, C. N., Lee, B. L. and Shi, C. Y. Aflatoxin $B_1$-induced 8-hydroxydeoxyguanosine formation in rat hepatic DNA. Carcinogenesis. 1995, 16, 419-422
  18. Tiemersma, E. W., Omer, R. E., Bunschoten, A., van't Veer, P., Kok, F. J., Idris, M. O., Kadaru, A. M., Fedail, S. S. and Kampman, E. Role of genetic polymorphism of glutathione-S-transferase T1 and microsomal epoxide hydrolase in aflatoxin-associated hepatocellular carcinoma. Cancer Epidemiol. Biomarkers Prev. 2001, 10, 785-791
  19. Ueng, Y. F., Shimada, T., Yamazaki, H. and Guengerich, F. P. Oxidation of aflatoxin B1 by bacterial recombinant human cytochrome P450 enzymes. Chem. Res. Toxicol. 1995, 8, 218-225
  20. Wild, C. P. and Turner, P. C. The toxicology of aflatoxins as a basis for public health decisions. Mutagenesis. 2002, 17, 471-481
  21. Wogan, G. N. and Newberne, P. M. Dose-Response Characteristics of Aflatoxin B1 Carcinogenesis in the rat. Cancer Res. 1969, 27, 2370-2376