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Mizukami S, Watanabe Y, Saegusa Y, Nakajima K, Ito Y, Masubuchi Y, Yoshida T, Shibutani M. Downregulation of UBE2E2 in rat liver cells after hepatocarcinogen treatment facilitates cell proliferation and slowing down of DNA damage response in GST-P-expressing preneoplastic lesions. Toxicol Appl Pharmacol 2017; 334:207-216. [PMID: 28899750 DOI: 10.1016/j.taap.2017.09.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Revised: 08/20/2017] [Accepted: 09/06/2017] [Indexed: 10/18/2022]
Abstract
We previously found downregulation of ubiquitin-conjugating enzyme E2E 2 (UBE2E2) in GST-P-positive (+) proliferative lesions produced by tumor promotion from early hepatocarcinogenesis stages in rats. Here we investigated the role of UBE2E2 downregulation in preneoplastic lesions of the liver and other target organs produced by tumor promotion in rats. Increased number of UBE2E2-related ubiquitination target proteins, phosphorylated c-MYC, KDM4A and KMT5A, was found in the UBE2E2-downregulated GST-P+ foci, compared with GST-P+ foci expressing UBE2E2. However, p21WAF1/CIP1, another UBE2E2 target protein, did not increase in the positive cells. Furthermore, the numbers of PCNA+ cells and γH2AX+ cells were increased in UBE2E2-downregulated foci. These results suggest sustained activation of c-MYC and stabilization of KMT5A to result in c-MYC-mediated transcript upregulation and following KMT5A-mediated protein stabilization of PCNA in GST-P+ foci, as well as KDM4A stabilization resulting in slowing down of DNA damage response in these lesions. Similar results were also observed in GST-P+ foci produced by repeated treatment of rats with a hepatocarcinogen, thioacetamide, for 90days. Hepatocarcinogen treatment for 28 or 90days also increased the numbers of liver cells expressing UBE2E2-related ubiquitination target proteins, as well as PCNA+ or γH2AX+ cells. Conversely, UBE2E2 downregulation was lacking in PPARα agonist-induced hepatocarcinogenesis, as well as in carcinogenic processes targeting other organs, suggestive of the loss of UBE2E2-related ubiquitination limited to hepatocarcinogenesis producing GST-P+ proliferative lesions. Our results suggest that repeated hepatocarcinogen treatment of rats causes stabilization of UBE2E2-related ubiquitination target proteins in liver cells to promote carcinogenesis.
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Affiliation(s)
- Sayaka Mizukami
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan; Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193, Japan.
| | - Yousuke Watanabe
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan; Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193, Japan.
| | - Yukie Saegusa
- Environment Health and Safety Division, Environment Directorate, OECD, 2, rue André Pascal, 75775 Paris, Cedex 16, France.
| | - Kota Nakajima
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan; Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193, Japan.
| | - Yuko Ito
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan; Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193, Japan.
| | - Yasunori Masubuchi
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan; Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193, Japan.
| | - Toshinori Yoshida
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.
| | - Makoto Shibutani
- Laboratory of Veterinary Pathology, Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan; Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.
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Rubio CA. Traditional serrated adenomas and serrated carcinomas in carcinogen-treated rats. J Clin Pathol 2016; 70:301-307. [PMID: 27566816 DOI: 10.1136/jclinpath-2016-204037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/01/2016] [Accepted: 08/03/2016] [Indexed: 01/23/2023]
Abstract
AIMS A recent review of archived sections from early experiments in rats showed neoplasias exhibiting serrated configurations. The aim was to assess the frequency of serrated neoplasias in the colon and small intestine of carcinogen-treated rats. METHODS While reviewing archival sections from early experiments in Sprague-Dawley (SD) and Fisher-344 (F-344) rats, we recently detected colonic and intestinal traditional serrated adenomas (displaying serrated or microtubular patterns) and serrated carcinomas. SD rats were injected 1,2-dimethylhydrazine (DMH) for 27 weeks whereas F-344 rats were fed with a pyrolysate (GLU-1) for 24 months. Filed sections from 358 colonic and small intestinal neoplasias were re-evaluated. RESULTS DMH-treated SD rats had 215 colonic neoplasias (1.4% were serrated adenomas, 7.9% microtubular adenomas, 2.8% serrated carcinomas and 2.8% microtubular carcinomas). GLU1-treated F-344 rats had 53 colonic neoplasias (1.9% were serrated adenomas and 20.8% microtubular adenomas), and 89 small intestinal neoplasias (1.1% were serrated adenomas, 42.7% microtubular adenomas and 6.7%, microtubular carcinomas). CONCLUSIONS DMH/SD-rats develop serrated and microtubular adenomas and carcinomas in the colon, whereas GLU1/F-344 rats develop microtubular adenomas in the colon and microtubular adenomas and carcinomas in the small intestine. The two rat-settings emerge as suitable models to study the molecular attributes of serrated and microtubular neoplasias under the standard conditions of the laboratory. This study is the first showing that a substantial number of serrated and particularly microtubular adenomas and carcinomas develop in the colon and small intestine of experimental rats. Importantly, serrated and microtubular neoplasias in rats recreate the histology of duodenal and colonic traditional serrated neoplasias in human beings.
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