Transgenic rats carrying copies of the human c-Ha-ras proto-oncogene exhibit enhanced susceptibility to N-butyl-N-(4-hydroxybutyl)nitrosamine bladder carcinogenesis

Ota, Tomohiro; Asamoto, Makoto; Toriyama‐Baba, Hiroyasu; Yamamoto, Fumi; Matsuoka, Yoichiro; Ochiya, Takahiro; Sekiya, Takao; Terada, Masaaki; Akaza, Hideyuki; Tsuda, Hiroyuki

doi:10.1093/carcin/21.5.391

Cited by 13 publications

(19 citation statements)

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“…Taken together with the fact that activating mutations in Hras are an early event in the development of a subset of human UC, this suggests that mutation of the Hras transgene is a primary factor in the development of invasive UC in the animal model described in this study. However, it has been demonstrated that enhanced UC development is not primarily due to mutations occurring in the transgene in Hras128 rats . Another factor in the susceptibility of Hras128 to UC could be relatively high expression of the human Hras transgene.…”

Section: Discussionmentioning

confidence: 99%

Carbonic anhydrase 2 is a novel invasion‐associated factor in urinary bladder cancers

Tachibana

Kato

et al. 2017

Cancer Science

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Rat bladder cancer is nearly always papillary non‐invasive urothelial carcinoma (UC). To establish an animal model mimicking invasive UC that arises from papillary non‐invasive UC in the bladder, male human c‐Ha‐ras proto‐oncogene transgenic rats (Hras128) were treated with 0.05% N‐butyl‐N‐(hydroxybutyl)nitrosameine (BBN) in their drinking water and/or 0.1% phenylethyl isothiocyanate (PEITC) in their diet as follows: BBN (8 weeks)→PEITC (8 weeks); PEITC (8 weeks)→BBN (8 weeks); BBN alone (16 weeks); PEITC alone (16 weeks); and no treatment. At the end of week 16, the highest incidence of invasive UC was observed in the BBN→PEITC group. Therefore, we used Hras128 rats treated with BBN followed by PEITC as a model of invasive bladder cancer to identify invasion‐associated proteins. Proteome analysis was performed to compare the protein profiles of invasive and non‐invasive UC in Hras128 rats. We identified 49 proteins that were either overexpressed or underexpressed in invasive UC but not in non‐invasive UC. Immunohistochemical analysis of carbonic anhydrase 2 (CA2), an overexpressed protein, showed that the relative number of CA2‐positive UC was significantly higher for invasive UC compared to non‐invasive UC in rats. Moreover, the incidence of CA2‐positive cancers was also significantly higher for human muscle‐invasive bladder cancer (MIBC) compared to non‐MIBC (NMIBC) and was positively associated with the progression of NMIBC. Our findings indicate that CA2 is an invasion‐associated factor and suggest that it could serve as a potential therapeutic molecular target for bladder cancers.

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Section: Discussionmentioning

confidence: 99%

Carbonic anhydrase 2 is a novel invasion‐associated factor in urinary bladder cancers

Tachibana

Kato

et al. 2017

Cancer Science

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“…9) Similarly, transgenic rats carrying a probesin promoter fused to the SV 40 T antigen gene have been shown to develop prostatic tumors. 10,11) In addition, we have generated transgenic rats utilizing the same gene construct employed for generation of human c-Ha-ras proto-oncogene transgenic mice 12) and shown them to be highly susceptible to induction of tumors in the mammary tissue by N-methyl-N-nitrosourea (MNU) and 7,12dimethylbenz[a]anthracene (DBMA), 12,13) in the urinary bladder by N-butyl-N-(4-hydroxybutyl)nitrosamine 14) and in the esophagus by N-nitrosomethylbenzylamine. 15) The model has also proven to be useful for demonstrating effects of inhibitory potential in the mammary gland.…”

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Rapid induction of skin and mammary tumors in human c‐Ha‐ras proto‐oncogene transgenic rats by treatment with 7,12‐dimethylbenz[a]anthracene followed by 12‐O‐tetradecanoylphorbol 13‐acetate

et al. 2004

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We have established a transgenic rat line carrying 3 copies of the human c-Ha-ras proto-oncogene with its own promoter region (Jcl/SD-TgN(HrasGen)128Ncc) (Hras128 rat), expression being detectable in almost all organs. We have already demonstrated that the rat is highly sensitive to mammary, esophagus and bladder carcinogenesis. In the present study, male and female transgenic and wild-type littermates were topically treated with 2.5 mg of 7,12-dimethylbenz[a]anthracene (DMBA) dissolved in 1.0 ml of acetone on the back skin at 50 days after birth. Starting 1 week thereafter, they were again topically treated with 100 nmol of 12-O-tetradecanoylphorbol 13-acetate (TPA) dissolved in 0.5 ml of acetone 3 times weekly for the following 31 weeks. In males treated with DMBA and/or TPA, skin tumors, including both squamous cell papillomas (SCP) and carcinomas (SCC), were preferentially induced at the DMBA-TPA painting sites: DMBA-TPA, 15/15 (100%); DMBA, 6/8 (75%); TPA, 1/6 (16.7%). They were also, unexpectedly, induced on remote scrotal skin: DMBA-TPA, 13/15 (86.7%); DMBA, 5/8 (62.5%); TPA, 0/6 (0%). Lesions were thus more frequent in the DMBA-TPA group than with DMBA or TPA alone. In females, adenomas and adenocarcinomas of the mammary glands were preferentially induced: DMBA-TPA, 12/14 (85.7%); DMBA, 6/8 (75%); TPA, 3/6 (50%), with only a few small skin papillomas at painting sites. Incidences and numbers of the mammary and skin tumors were much greater in Hras128 rats than in their wild-type counterparts. PCR-RFLP analysis of the transgene indicated that the percentage of the cell populations harboring a mutation in codons 12 and/or 61 ranged from 2% to 60% in individual tumors; skin tumors showed more mutations in codon 61 in the DMBA-treated groups. In contrast, no mutations were detected in the endogenous rat c-Ha-ras gene. These results indicate that the Hras128 rat is highly susceptible to DMBA-TPA skin and mammary carcinogenesis, thus providing a unique painting model for skin as well as mammary gland carcinogenesis, that would be suitable for investigating the role of transgene mutations. (Cancer Sci 2004; 95: 205-210) arious transgenic and knockout mice have proven to be good animal models for analysis of gene functions. In the chemical carcinogenesis field, transgenic mice carrying human c-Ha-ras proto-oncogenes (rasH2 mice) have been shown to be highly susceptible to induction of skin, lung and lymphatic cell tumors by various carcinogens.1-6) However, rats are more frequently used for analysis of events occurring during tumor development. There are thus many more basic experimental data available for rats than mice regarding chemical carcinogenesis, and a variety of preneoplastic lesions, including hepatocellular enzyme-altered foci, for example, are available in rats as surrogate markers for cancer development. 7,8) Furthermore, mammary cancers in rats can be induced without the complication of a viral etiology irrelevant to the disease in man. So far, only limited types of transgenic rats have been de...

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“…7) In humans, Ki-ras mutations are preferentially found in colon, 8,9) pancreatic duct 10) and bile duct carcinomas, 11) and N-ras mutations are typically seen in myeloid leukemia. 12) We have generated a transgenic rat line, harboring copies of a human c-Ha-ras proto-oncogene (Hras128 rat), and have shown that these animals are highly susceptible to mammary, 13,14) bladder 15) and esophageal 16) carcinogens.…”

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Preferential mammary carcinogenic effects of 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) in human c‐Ha‐ras proto‐oncogene transgenic rats

et al. 2004

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he Ras family is composed of three members, Harvey Ras, Kirsten Ras and N-Ras, which exhibit mutations at variable frequencies in various human and animal tumors, 1) with involvement appearing to be tissue-specific. 2, 3) For example, with N-methyl-N-nitrosourea (MNU) in experimental animals, Haras mutations are found primarily in mammary tumors, [4][5][6] while colon tumors generally have Ki-ras mutations. 7) In humans, Ki-ras mutations are preferentially found in colon, 8,9) pancreatic duct 10) and bile duct carcinomas, 11) and N-ras mutations are typically seen in myeloid leukemia. 12) We have generated a transgenic rat line, harboring copies of a human c-Ha-ras proto-oncogene (Hras128 rat), and have shown that these animals are highly susceptible to mammary, 13,14) bladder 15) and esophageal 16) carcinogens.Heterocyclic amines found in overcooked foods are both mutagenic and carcinogenic to animals, 17) and 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP), the most abundant in our daily diet, 18) has been shown to induce primarily colon, mammary and prostate tumors in rats. [19][20][21] PhIP intake in food has also been implicated as an important risk factor in humans 22,23) although further analysis of the interactions between PhIP and relevant macromolecules is required for a full understanding of the carcinogenic processes.Although mutational analyses of tumors induced by PhIP have been conducted, 24) specific molecular targets have yet to be elucidated. One problem is that the relatively weak carcinogenic potential requires the use of long experimental periods for lesion induction. This study was conducted to analyze the susceptibility of Hras128 rats to PhIP, in the hope of overcoming the above problem. We show here that Hras128 rats are in fact highly susceptible to PhIP mammary carcinogenesis, and multiple tumors of various morphological types develop in a short period. Furthermore, they feature mutations of the transgene along with down-regulation of BRCA1. Materials and MethodsAnimals and experimental protocol. Seven-week-old Hras128 rats of both sexes were maintained on basal diet (Oriental MF, Oriental Yeast Co., Ltd. Tokyo) with tap water ad libitum under standard conditions. 13) Seven females and 18 males were treated with PhIP HCl salt (NARD Institute, Osaka), at doses of 100 mg and 80 mg/kg body weight, respectively, by gastric intubation, from 3 to 4 times a week over a 9-week period (total, 8 times in females and 10 times in males). Five female and 20 male Hras128 rats were similarly treated with vehicle (saline). Sacrifice was at week 12 for females and week 30 for males. Seven female and 20 male wild-type littermates were also treated with PhIP, and 8 female and 20 male wild-type littermates received the vehicle (saline).The experiments were conducted according to the "Guidelines for Animal Experiments in the National Cancer Center Japan" promulgated by the Committee for Ethics of Animal Experimentation.Tissue preparation. Immediately after killing of the animals, mammary tumors wer...

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Transgenic rats carrying copies of the human c-Ha-ras proto-oncogene exhibit enhanced susceptibility to N-butyl-N-(4-hydroxybutyl)nitrosamine bladder carcinogenesis

Cited by 13 publications

References 25 publications

Carbonic anhydrase 2 is a novel invasion‐associated factor in urinary bladder cancers

Carbonic anhydrase 2 is a novel invasion‐associated factor in urinary bladder cancers

Rapid induction of skin and mammary tumors in human c‐Ha‐ras proto‐oncogene transgenic rats by treatment with 7,12‐dimethylbenz[a]anthracene followed by 12‐O‐tetradecanoylphorbol 13‐acetate

Preferential mammary carcinogenic effects of 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) in human c‐Ha‐ras proto‐oncogene transgenic rats

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