• Toxicological Research
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• v.16 no.4
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• pp.275-284
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• 2000

The organ culture model of the whole mammary gland has many advantages for the study of branching morphogenesis and biological characteristics, including tumorigenesis. Prior to whole gland organ culture, rats were treated with 7,12-dimethylbenz[a]anthracene (DMBA) or N-methyl-N-nitrosourea (MNU) for one week. The tramdorming effect and the morphological changes were assessed by the whole mount preparations and histopathological examination in terminal end buds (TEB), terminal ducts (TD), alveolar buds (AB), alveolar lobules (AL) and hyperplastic alveolar nodules (HAN) of the mammary gland. Grossfindings of the mammary glands at dissection were higher branching morphogenesis and larger volume in carcinogen-treated groups than in carcinogen-non-treated groups. Results of the whole mount method were coincided with those of the histopathological observations. Circular TEB, normally maintained AB, AL, and high cellular density were more frequently observed in carcinogen-treated groups than in carcinogen-nan-treated groups. Histopathologically, as a preneoplastic marker, HAN was maintained only in mammary organ culture of the carcinogen-treated groups. These findings suggest that in vivo trans-formation effects by carcinogens persisted during the mammary organ culture. These results were more characteristic in DMBA than in MNU-treated group. Ducts and terminal ducts appeared to have lost morphology during their growths in case of without diethylstilbestrol (DES). The fact that in vitro organ culture without DES was resulted in abnormal ductular morphogenesis confirms that DES is a physiological regulator of ductular epithelial cell growth.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.39-40
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• 2003

Ochratoxin A (OA), a potent nephrotoxin in several species, is knownto be a renal carcinogen in animals and is implicated in the etiology of Balkan endemic nephropathy (BEN). The NTP (National Toxicology Program) classified Ochratoxin A as having clear evidence of carcinogenic activity, based on uncommon tubular adenomas and tubular cell carcinomas of the kidney and multiple fibroadenomas of the mammary gland, seen in the rat.(omitted)

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.4
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• pp.570-575
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• 2002

Effects of active immunization against native 14-mer somatostatin (SRIF, somatotropin releasing inhibiting factor) and its two 14-mer-somatostatin analogues on the milk production in rat mammary cells were studied. Native SRIF, Tyr11-somatostatin (Tyr11-SRIF), and D-Trp8, D-Cys14-somatostatin (Trp8Cys14-SRIF) were conjugated to bovine serum albumin (BSA) for immunogen preparation. Twenty-four female Sprague-Dawley rats were divided into four groups and immunized against saline (Control), SRIF, Tyr11-SRIF, and Trp8Cys14-SRIF at five weeks of age. Booster immunizations were performed at 7, 9, and 11 weeks of age. SRIFimmunized rats were mated at 10 weeks of age. The blood and mammary glands were collected at day 15 post-pregnancy and -lactation. To measure the amount of milk protein synthesis in the mammary gland, mammary cells isolated from the pregnant and the lactating rats, were cultured in the presence of $^3H$-lysine. No significant differences in growth performance, concentration of growth hormone in the circulation, and the amount of milk protein synthesis were observed among the groups. Inductive levels of serum anti-SRIF antibody in the SRIF and Tyr11-SRIF groups but not in the Trp8Cys14-SRIF group, were significantly higher than that of the control group during the pregnancy and lactation periods. The result suggests that active immunization against native 14-mer SRIF and Tyr11-SRIF was able to induce anti-SRIF antibodies, but did not affect the milk protein synthesis.

• Korean Journal of Veterinary Research
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• v.23 no.1
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• pp.57-67
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• 1983

The present study was carried out to observe the histopathological changes in the mammary gland of lactating rats and rabbits injected with dexamethasone. White rats were intramuscularly injected with 0.25mg, 0.5mg or 1.0mg of dexamethasone sodium phosphate (containing $9{\alpha}$-fluoro-$16{\alpha}$-methylprednisolone, 5.0mg/ml) daily for 3 to 10 days on the 3rd day after parturition and white rabbits were intramammary infused with 4mg or 20mg of dexamethasone daily for 4 days on 7th day after parturition. The histopathological changes of the mammary glands, ovaries and adrenal glands of rats and rabbits were observed with light microscope. In the mammary glands of rats, the microscopic findings encountered were decrease of the milk in the alveolar lumina, necrosis and desquamation of epithelial cells, atrophy of alveoli, proliferation of fibroblasts and thickness of alveolar walls, destruction of alveoli, presence of fat droplets within the glandular epithelial cells, infiltration of mononuclear cells and proliferation of adipose tissue, which were relative to the dose and duration of injection. Especially, in the cases of the administration of large doses or long duration, there were severe fibrosis and focal necrosis of glandular tissue. In the mammary glands of rabbits, the morphological changes were similar to those findings in the rats. The milk in the alveolar lumina was decreased gradually according to the dose and duration of injection, while milk fat concentration regarded to increase. In the histological findings of ovaries, necrosis of granulosa cellos, vacuolization and necrosis of luteal cells, atrophy and necrotic foci in the corpora lutes were observed. In the adrenal glands, hyperemia, hemorrhage, vacuolization of adrenal cortical cells, necrotic foci and atrophy of adrenal cortex were observed.

• Korean Journal of Veterinary Research
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• v.41 no.4
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• pp.549-555
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• 2001

Indole-3-carbinol (I3C), one component of cruciferous vegetables (the Fammily of Cruciferae), has been shown to exert its chemopreventive effect in liver, colon and mammary tissue before or concurrent exposure of carcinogen, but there have been several evidences that consumption of I3C induced tumor promotion in some tissues. Our studies were investigated to examine the modifying effects of I3C in the 7,12-dimethylbenz[$\alpha$]anthracene (DMBA) induced rat mammary gland tumor model. Fifty-two female Sprague-Dawley rats were randomly divided into five groups. Animals of the group 1 were given the diet containing 100ppm I3C and animals of the groups 2 and 4 were given the diet containing 300ppm I3C from 6 weeks of age. At 7 weeks of age, the animals of the groups 1, 2 and 3 were intubated with DMBA. All amimals were killed at 20 weeks after carcinogen treatment. There were significant increases of food consumption in I3C feeding groups compared with those of basal diet feeding groups. The incidences of the mammary tumors in the group 1, 2 and 3 were 75.0% (9/12), 56.3% (9/16) and 93.8% (15/16), respectively and the average number of tumors of group 1 (DMBA+I3C 100ppm: $2.08{\pm}0.61$) and 2 (DMBA+I3C 300ppm: $1.19{\pm}0.32$) were significantly lower than that of group 3 (DMBA alone: $4.63{\pm}0.72$) at the value of P<0.05 and P<0.001, respectively. In the pathological examination of appearing tumors, most of them were adenocarcinoma. Many epithelial cells of tumors showed strong estrogen receptor (ER) $\alpha$ expression but there were slight difference of ER $\alpha$ expression among the type of tumors. We suggest that pre-initiation treatment of I3C has an inhibitory effects on mammary carcinogenesis induced by DMBA.

• Journal of Nutrition and Health
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• v.39 no.4
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• pp.347-356
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• 2006

It is reported that a fermented soybean food, Doenjang, has srong antimutagenic and cytotoxic effect on cancer cells. This study investigated the effect of Chungkookjang, another traditional popular Korean soybean fermented food, on growth of cancer cells: HL-60, SNU-638 and MCF-7, and also its in vivo antitumorigenic effect in DMBA-induced mammary tumor rat model. For the in vitro study, Chungkookjang and steamed soybeans were extracted with ethanol and sequentially fractioned with 5 kinds of solvents differing in grades of polarity such as hexane, dichloromethane, ethylacetate, butanol and water. Almost all Chungkookjang extracts significantly inhibited the growth of HL-60 (human leukemic cancer cell), SNU-638 (human gastric cancer cell) and MCF-7 (human breast cancer cell) when compared to steamed soybean extracts. Butanol fraction of Chungkookjang extract especially showed a remarkable inhibitory effect in all the three kinds of cancer cells. To induce a mammary gland tumor, DMBA (50 mg/BW) was administered to 50 day-old female rats and followed by Chungkookjang or steamed soybean supplemented diets. Freezedried Chungkookjang powder (20% of diet in wet weight) was added to AIN-93G based diet for the Chungkookjang group of rats. Likewise, steamed soybean powder containing equal protein content to that of Chungkookjang powder was supplemented to soybean group of rats. At 13 weeks later, the mammary tumor incidence, average tumor number and tumor weight a rat were lower in Chungkookjang group compared to the control or soybean group. In conclusion, Chungkookjang showed a strong inhibitory effect on cancer cell growth in vitro, as well as a more preventive effect against chemically induced mammary tumorigenesis in vivo, while steamed soybeans did not. Therefore, these results suggest that Chungkookjang acquire its anticancer activity through the fermentation process.

• Molecular & Cellular Toxicology
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• v.5 no.3
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• pp.222-229
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• 2009

Our previous finding that pre-initiation treatment of indole-3-carbinol (I3C) represents a chemopreventive effect in dimethylbenz[a]anthracene (DMBA)-induced mammary carcinogenesis has prompted us to test the global expression of genes at an early stage. Rats were continuously fed 300 ppm I3C in their diet at 6 weeks of age and were injected with DMBA at 7 weeks of age, and were sacrificed at 8 weeks of age. Global gene expression analysis using oligonucleotide microarrays was conducted to detect altered genes in DMBA- or DMBA plus I3C-treated mammary glands. Altered genes were identified by fold changes of 1.2 and by t-test (P<0.05) from the log ratios of the hybridization intensity of samples between control (Group 1) and DMBA (Group 2), and from those of samples between DMBA (Group 2) and DMBA plus I3C (Group 3). From these genes, we chose altered genes that were up- or down-regulated by DMBA treatment and recovered to the control level by I3C treatment. For early stage of carcinogenesis, I3C treatment induced the recovery to normal levels of several genes including cell cycle pathway (cyclin B2, cell division cycle 2 homolog A), MAP signaling pathway (fibroblast growth factor receptor 1, platelet derived growth factor receptor, beta polypeptide), and insulin signaling (protein phosphatase 1, regulatory (inhibitor) subunit 3B and flotillin 2), which were up-regulated by DMBA treatment. In addition, I3C treatment induced the recovery to normal levels of several genes including those of MAPK signaling (transforming growth factor, beta receptor 1 and protein phosphatase 3, catalytic subunit, beta isoform), which were down-regulated by DMBA treatment. These results suggest that the targeting of these genes presents a possible approach for chemoprevention in DMBA-induced mammary carcinogenesis.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8411-8418
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• 2016

The effect of Eruca sativa seed extract (SE) on nuclear factor kappa B (NF-${\kappa}B$), cyclooxygenase-2 (COX-2) and B-cell lymphoma-2 (Bcl-2) gene expression levels was investigated in rat mammary gland carcinogenesis induced by 7,12 dimethylbenz(${\alpha}$)anthracene (DMBA). DMBA increased NF-${\kappa}B$, COX-2 and Bcl-2 gene expression levels and lipid peroxidation (LP), while, decreased glutathione-S-transferase (GST) and superoxide dismutase (SOD) activities and total antioxidant concentration (TAC) compared to the control group. After DMBA administration, SE treatment reduced NF-${\kappa}B$, COX-2 and Bcl-2 gene expression levels and LP. Hence, SE treatment reduced inflammation and cell proliferation, while increasing apoptosis, GST and SOD activities and TAC. Analysis revealed that SE has high concentrations of total flavonoids, triterpenoids, alkaloids and polyphenolic compounds such as gallic, chlorogenic, caffeic, 3,4-dicaffeoyl quinic, 3,5-dicaffeoyl quinic, tannic, cinnamic acids, catechin and phloridzin. These findings indicate that SE may be considered a promising natural product from cruciferous vegetables against breast cancer, especially given its high antioxidant properties.

• Applied Biological Chemistry
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• v.19 no.3
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• pp.121-129
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• 1976

A high concentration of myo-Inositol in rat's milk was observed (61-91mg. of myo-Inositol per 100g of milk) by gas-liquid chromatographic method, using a 3% SE-52 column. Feeding experiments showed that approximately 85% of myo-Inositol in milk was from dietary origin: the rest was considered to be synthesized by 1L-myo-Inositol-1-phosphate lyase. Results suggested that the biosynthesis was not sufficiently high to permit the maintenance of its myo-Inositol level in milk. However, study $using(^{14}C)-glucose$ injection into lactating female rats confirmed biosynthesis of myo-Inositol from glucose in mammary gland. This biosynthesis reached a maximum within an hour after $(^{14}C)-glucose$ injection intraperitoneally as lactose biosynthesis did. Study using $(^3H)-myo-Inositol$ confirmed that most of the myo-Inositol in milk was transported from blood plasma myo-Inositol against a concentration gradient. About four hours after the beginning of the injection of $(^{14}C)-glucose$, the specific radioactivity of myo-Inositol in milk was 8% of that of glucose in the blood. When $(^3H)-myo-Inositol$ was injected, the specific radioactivity of myo-Inositol in milk was about 26% of that of blood six hours after injection.

• Archives of Pharmacal Research
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• v.21 no.3
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• pp.298-304
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• 1998

Retinoids are applied to not only cancer prevention but also cancer chemotherapy by stimulating differentiation of cells. We studied differentiation inducing effect of all-trans retinoic acid (ATRA) by studying proportion of high dense fractions of stem-like cells and the size of S phase fraction in cell cycle. From mammary organoids obtained from 7- to 8-week old F344 female rat mammary gland, we cultured rat mammary epithelial cells (RMEC) and treated physiological doses of $10^{-6}$, $10^{-7}$, and $10^{-8}$ M ATRA from the first day and then cultured for 4, 7, and 14 days. After that, immunostaining was performed using peanut agglutinin (PNA) and anti-Thy-1.1 monoclonal antibody (Thy-1.1) that can be used as markers of differentiation. We separated four different cell subpopulations by flow cytometry: cells negative to both reagents (B-), PNA-positive cells (PNA+), Thy-1.1-positive cells (Thy-1.1+), and cells positive to both reagents (B+). We observed continuous decreases of high dense fractions of stem-like cells (PNA+ subpopulations) for 14 days and as much decreases as high doses of ATRA, which were thought to be proportional to doses of ATRA. We labeled RMEC with bromodeoxyuridine and investigated cell cycle fractions that went through S phase. We observed a tendency of decrease of S phase fraction with time in culture, which, is thought to be related to continuous decreases of PNA+ subpopulations and inhibitory role of ATRA on cell cycle. These results suggest that physiological doses of ATRA could stimulate differentiation of RMEC and convert stem-like RMEC to differentiated cells in SFM for a relatively long period of 14 days.