Mammary tumors, in mice

The photodynamic effect of chloroaluminum(III) phthalocyanine ((47), with C1A1 in place of Zn), a commercial product, was reported by Ben-Hur and Rosenthal.302 The photosensitizer was delivered in ethanol to cultures of Chinese hamster fibroblasts. After equilibration (16 h), exposure to visible light (fluence rate 64 Wm-2) of a suspension in PBS for 2 min gave a 3 log kill. Lack of water solubility is a problem, and for in vivo PDT of EMT-6 mammary tumors in mice a Cremophor emulsion was employed.303 The compound was a more effective PDT sensitizer than... 

In addition to the above-mentioned examples of tumors with disputed relevance to humans, mammary tumors in mice have been regarded as being of uncertain relevance for humans. The incidence of mammary tumors in mice has been shown to be highly influenced by environmental factors such as stress (Riley 1975), which complicates the interpretation of increased mammary tumor incidence in a carcinogenicity study. 

Carcinogenicity of hydroxylamine and its salts has not been demonstrated. Several studies have shown a decreased incidence of spontaneous mammary tumors in mice exposed to the sulfate and hydrochloride. There was some indication of an increase in the incidence of spontaneous mammary tumors when the sulfate was administered to older animals whose mammary glands were already well developed. 

It is of interest to compare our results with the two classic studies from the literature using multiple levels of fat. Silverstone and Tannenbaum (42) found that the incidence of spontaneous mammary tumors in mice increased as the level of a partially hydrogenated mixture of cottonseed and soybean oil was increased from 2 to 4% of the diet up to 12 or 16% by weight. Further increments in fat intake did not significantly increase tumor incidence. Carroll and Khor (43) examined the effects of corn oil at 0.5, 5.0, 10.0 and 20.0% of the diet by weight on DMBA-induced breast cancer in rats. They observed that rats fed 0.5% or 5.0% dietary corn oil showed a slightly lower incidence and a greatly reduced total tumor number than those fed 10 or 20% corn oil. The tumor yields were not increased by the 10-fold increase from 0.5 to 5.0% or the 2-fold increase from 10 to 20% corn oil. 

Vanadium in the drinking water of mice had no influence on tumor induction by the known carcinogen 1,2-dimethylhydrazine given by subcutaneous injection (Kingsnorth et al. 1986), but dietary vanadium did decrease mammary tumors in mice caused by 1-methyl-1-nitrosourea administered concurrently (Thompson et al. 1984). The latter effect may have been due to interaction with DNA. 

Sass, B., Vlahakis, G., and Heston, W. E. (1982). Precursor lesions and pathogenesis of spontaneous mammary tumors in mice. Toxicol Pathol 10, 12-21. 

Schrauzbe GN, Kuehn K and Hamm D (1979) Effects of dietary selenium and lead on the genesis of spontaneous mammary tumors in mice. Biol Trace Elem Res 3 185-196. 

Bentvelzen P., Daams J.H., Hageman P., Calafat J. (1970). Genetic transmission of viruses that incite mammary tumor in mice. Proc. Natl. Acad. Sci. USA 67 377-384. 

Bradlow HE, Michnovicz J, Telang NT, Oxborne MP, Effects of dietary indole-3carbinol on estradiol metabolism and spontaneous mammary tumors in mice. Carcinogenesis 1991 12 1571-1574. 

There are striking coincidences in effective Se levels between experiments of immunoenhancement and carcinostatic suppression when injected or ingested Se levels are compared. Data presented by Schrauzer (1976) for the reduction of mammary tumors in mice showing a dose-related effect of dietary Se can be superimposed with the dose-related enhancement of PFC and anti-SRBC antibodies in mice. Levels of dietary supplemented Se in animal experiments that were effective in immunoenhancement (Spallholz et al., 1973a) and tumor reduction (Schrauzer, 1976) were 1.25 and 2.0 ppm Se respectively. 

Mice fed AIN-76A diet in the control group were intubated with 1 mg of DMBA per mouse once a week for 5 weeks. The mice developed DMBA-induced 0.025, 0.50, 0.73 and 1.08 palpable mammary tumors per mouse at 3, 9, 13, or 20 weeks, respectively, after the last dose of DMBA treatment (Table I). Mammary tumors in mice that were killed at 20 weeks after the last dose of DMBA were confirmed histopathologically. The first tumors in control mice appeared at 3 weeks after the last dose of DMBA treatment. In the parallel group... 

Dmochowski, L. 1953. The milk agent in the origin of mammary tumors in mice. In Advances in Cancer Research 1 103-160, J.B. Greenstein and A. Haddow, eds. New York Academic Press. 

It is not appropriate to generali2e the carcinogenicity of this class of compounds. Nitrofura2one appears to increase the incidence of benign mammary tumors in rats. The tumorigenic activity of fura2ohdone is expressed by an increase in the incidence of spontaneous tumors in both mice and rats. Bioassays of nitrofurantoin in several species of mice and rats failed to reveal any evidence of direct tumorigenic activity. Ovarian tumors have been reported in B C F mice, but these are beheved due to an indirect expression of toxicity (14,15). 

For example, 7,12-dimethylbenz[a]anthracene is a particularly potent carcinogen for the mammary gland of young female Sprague-Dawley rats after oral or intravenous administration (25,26), dietary benzo[a]pyrene leads to leukemia, lung adenoma and stomach tumors in mice (27), and either of these hydrocarbons can induce hepatomas in male mice when injected on the first day of life (28). Nevertheless, the mouse skin system has proved to be particularly valuable because of the rapidity of tumor induction, the ease of detection of tumors and because the multi-stage nature of the carcinogenic process was experimentally established in this system. 

Griffin and coworkers (U.K.) reported work on ECT of mammary carcinoma in mice.67 Tumor destruction was found to be significantly greater, for a given charge, when anode was implanted in the tumor with cathode outside it. The results demonstrated a linear relationship between the volume of tumor regression induced and the quantity of electric charge passed. 

Provinciali M, Papalini F, Orlando F, Pierpaoli S, Donnini A, Morazzoni P, Riva A, Smorlesi A. (2007) Effect of the silybin-phosphatidylcholine complex (IdB 1016) on the development of mammary tumors in HER-2/neu transgenic mice. Cancer Res 67 2022-2029. 

Willett, W. C., M. J. Stampfer, J. E. Manson, et al. Coffee consumption and coronary heart disease in women. J Am Med Ass 1996 275(6) 458-462. Nagasawa, H., M. Yasuda, S. Sakamoto, and H. Inatomi. Suppression in coffee cherry of the growth of spontaneous mammary tumors in SHN mice. Anticancer Res 1996 16(1) 151-153. Barrett, B. Medicinal plants of Nicaragua s Atlantic coast. Econ Bot... 

Dichloroethylene has been shown to cause mammary tumors in both rats and mice and kidney adenocarcinomas in mice (3). This compound was found only once during the survey, but it was found at 20 /zg/L in treated water, a level significantly higher than the WHO action limit. Further investigation is necessary to determine the significance of this observation. 

None of the selected triazines showed any evidence of inducing tumors in mice, despite high feeding levels doses ranged from 87 to 1140mg/kg/day and were equal to or exceeded the MTD. The chloro-.v-triazines (e.g., atrazine, cyanazine, propazine, and simazine) resulted in either an increased incidence or an earlier onset of mammary tumors when administered to female SD rats at high feeding levels, as presented in Table 25.7. 

Table II. Effect of Dietary Selenium on the Incidence of Mammary Tumors in C H/St Mice...

Bouchard, L., Lamarre, L., Tremblay, P. J., and Jolicoeur, P. (1989). Stochastic appearance of mammary tumors in transgenic mice carrying the MMTV/c-neu oncogene. Cell51, 931-936. 

Spontaneous incidences in tumors are commonly seen in untreated rats and mice, and vary from strain to strain. Examples include pituitary and mammary tumors in rats, and liver and lung tumors in mice. The incidences of tumors can vary, and even today. 

The development of hver tumors in mice and an increased incidence of mammary fibroadenomata in female rats at one time caused concern in the USA, although animal studies elsewhere and chnical studies have shown no evidence of tumor-forming potential. 

Phenanthrene may cause skin allergy, and is considered phototoxic. It has induced sister chromatid exchanges in Chinese hamster cells. The available data are inadequate to permit an evaluation of the carcinogenicity of phenanthrene to experimental animals however, a number of other PAHs have caused tumors in laboratory animals via oral, inhalation, and dermal exposures. A single oral dose of phenanthrene did not induce mammary tumors in rats, and a single subcutaneous injection did not result in treatment-related increases in tumor incidence in mice. Neonate mice administered intraperitoneal or subcutaneous injections of phenanthrene also did not develop tumors. No skin tumors were reported in two skin painting assays with mice. Phenanthrene was also tested in several mouse skin initiation-promotion assays. It was active as an initiator in one study, inactive as an initiator in four others, and inactive as a promoter in one study. 

Inhibition of 7,I2-dimethylbenz[a ]anthracene (DMBA) induced mammary tumors Inhibition of spontaneous mammary tumors (in SHN mice)... 

Siegel PM, Ryan ED, Cardiff RD et al (1999) Elevated expression of activated forms of Neu/ErbB-2 and ErbB-3 are involved in the induction of mammary tumors in transgenic mice implications for hmnan breast cancer. EMBO J 18i2149-2164... 

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