Organ differences in the impact of p27kip1 deficiency on carcinogenesis induced by N-methyl-N-nitrosourea
Article first published online: 19 DEC 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Journal of Applied Toxicology
Volume 33, Issue 6, pages 471–479, June 2013
How to Cite
Ogawa, K., Murasaki, T., Sugiura, S., Nakanishi, M. and Shirai, T. (2013), Organ differences in the impact of p27kip1 deficiency on carcinogenesis induced by N-methyl-N-nitrosourea. J. Appl. Toxicol., 33: 471–479. doi: 10.1002/jat.1770
- Issue published online: 22 APR 2013
- Article first published online: 19 DEC 2011
- Manuscript Accepted: 7 OCT 2011
- Manuscript Revised: 22 SEP 2011
- Manuscript Received: 23 AUG 2011
- knockout mice;
To evaluate the impact of p27 on carcinogenesis in various organs, N-methyl-N-nitrosourea (MNU), a direct-acting alkylating agent, was given to p27 knock-out mice. Groups of 20–40 male and female mice with null, hetero- or wild-type p27 alleles were given drinking water containing 240 ppm MNU or distilled water every other week for five cycles. The incidence and multiplicity of the induced proliferative lesions were then histologically evaluated at weeks 14 and 20. MNU treatment induced various lesions including squamous hyperplasia and squamous cell carcinoma in the forestomach, atypical hyperplasia and adenocarcinomas in the fundic and pyloric glands, adenomas and adenocarcinomas in the duodenum, malignant lymphomas in the thymus, liver, kidney and spleen and alveolar hyperplasia, adenomas, adenocarcinomas and malignant lymphomas in the lung. Although the incidences of the lesions in the forestomach, fundic and pyloric glands did not differ among the p27 genotypes, those of alveolar hyperplasia of the lung and malignant lymphoma of the thymus were significantly increased in p27-null males as compared with both wild- and hetero-type animals. Moreover, in both p27+/+ and p27+/− cases, the rates for p27-positive cells were obviously increased in proliferative lesions of the pyloric gland and the lung. However, an increased rate of p27-positive cells was not observed in malignant lymphoma of the thymus. These findings suggest that p27 does not control the cell cycle equally in all organs affected by MNU-induced carcinogenesis. Copyright © 2011 John Wiley & Sons, Ltd.