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Wakui S, Takahashi H, Muto T. In Utero Exposure to 3,3',4,4', 5-Pentachlorobiphenyl Dose-Dependently Induces N-butyl-4-(hydroxybutyl) Nitrosamine in Rats With Urinary Bladder Carcinoma. Toxicol Pathol 2022; 50:366-380. [PMID: 35045775 DOI: 10.1177/01926233211064180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Polychlorinated biphenyls (PCBs) are fat-soluble environmental pollutants that can accumulate in adipose tissue or be secreted in milk. N-butyl-4-(hydroxy butyl) (BBN), a rat bladder carcinogen, recruits the host metabolism to yield its ultimate carcinogenic form via CYP1s. Since estrogen receptors (ERs) mediate biological responses important for the growth of bladder carcinoma, we investigated PCNA, Cyclin D1, ERs, CYP1s, and AhR expression in BBN rat bladder carcinomas with prenatal PCB exposure. Female SD rats were treated with 7.5 μg, 250 ng, and 2.5 ng of 3,3',4,4',5-pentachlorobiphenyl (PCB126)/kg or vehicle on days 13 to 19 post-pregnancy. Six-week-old male offspring were treated with 0.05% BBN for 10 weeks before being anesthetized and the urinary bladder wall incised to expose the bladder carcinomas. N-butyl-4-(hydroxybutyl) bladder carcinoma incidence increased with prenatal PCB exposure dose-dependently. In bladder carcinoma, PCB126 exposure significantly increased PCNA, D1, ERα, CYPIA1, CYP1B1, and AhR expression dose-dependently, and increased ERα expression was particularly prominent. However, the expression of ERβ was low, independent of the volume of PCB126 given, indicating similarity to the Vehicle group. We conclude that prenatal PCB126 exposure in rats can induce PCB126 to dose-dependently metabolize BBN via CYP1A1, and contribute to bladder carcinogenesis with upregulation of ERα expression.
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Affiliation(s)
- Shin Wakui
- Laboratory of Toxicology, Azabu University School of Veterinary Medicine, Kanagawa, Japan
| | - Hiroyuki Takahashi
- Department of Pathology, The Jikei University School of Medicine, Tokyo, Japan. Muto is now with Kumiai Chemical Industry Co., Ltd. Japan
| | - Tomoko Muto
- Laboratory of Toxicology, Azabu University School of Veterinary Medicine, Kanagawa, Japan
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Wakui S, Motohashi M, Satoh T, Shirai M, Mutou T, Takahashi H, Wempe MF, Endou H, Inomata T, Asari M. Nuclear Morphometric Analysis of Leydig Cells of Male Pubertal Rats Exposed In Utero to Di(n-butyl) Phthalate. J Toxicol Pathol 2013; 26:439-46. [PMID: 24526819 PMCID: PMC3921929 DOI: 10.1293/tox.2013-0031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 08/05/2013] [Indexed: 11/30/2022] Open
Abstract
We recently reported that prenatal rat exposure to di(n-butyl) phthalate (DBP) induced Leydig cell (LC) hyperplasia after nine weeks (wks) of age, yet the number of LCs was similar to that of the vehicle group until seven weeks. Nuclear pleomorphism of hyperplastic LCs is common and is considered to be continuous progressive degeneration. Thus, computer-assisted image cell nuclear analysis of LCs was performed on 5- and 7-wk-old Sprague-Dawley (SD) rats whose dams had been administered DBP (i.g.) at 100 mg/kg/day or vehicle (corn oil) on gestation day 12 to 21. The results of the 5-wk-old DBP group were similar to those of the vehicle group; LC nuclei of the 7-wk-old DBP group showed normal ploidy and similar amounts of DNA. However, the size, elongation and peripheral chromatin aggregation parameters were significantly higher, and the reticular chromatin distribution and isolated chromatin aggregation parameters were significantly lower compared with the vehicle group. The present study quantitatively demonstrated nuclear morphological alterations in rat LCs at 7 wks old (puberty) due to the prenatal DBP administration before apparent LC hyperplasia developed.
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Affiliation(s)
- Shin Wakui
- Department of Toxicology, Laboratory Animal Science, and Veterinary Anatomy, Azabu University School of Veterinary Medicine, 1-17-71 Chuo, Sagamihara, Kanagawa 252-5201, Japan
| | - Masaya Motohashi
- Department of Toxicology, Laboratory Animal Science, and Veterinary Anatomy, Azabu University School of Veterinary Medicine, 1-17-71 Chuo, Sagamihara, Kanagawa 252-5201, Japan
| | - Takemi Satoh
- Kokusan Co., Ltd., 7-8-16 Nishibori Sakura, Saitama 338-0832, Japan
| | - Masaru Shirai
- Department of Toxicology, Laboratory Animal Science, and Veterinary Anatomy, Azabu University School of Veterinary Medicine, 1-17-71 Chuo, Sagamihara, Kanagawa 252-5201, Japan
| | - Tomoko Mutou
- Drug Safety Testing Center, 25-1 Kuroiwa, Yoshimi Hiki, Saitama 335-0116, Japan
| | - Hiroyuki Takahashi
- Department of Pathology, The Jikei University School of Medicine, 3-35-8 Nishishimbashi, Minato, Tokyo 105-8461, Japan
| | - Michael F. Wempe
- School of Pharmacy, University of Colorado, Anschutz Medical Campus, 12850 East Montview Blvd., Aurora, CO 80045, USA
| | - Hitoshi Endou
- J-Pharma Co., Ltd., 75-1 Turumi, Kanagawa 230-0046, Japan
| | - Tomoo Inomata
- Department of Toxicology, Laboratory Animal Science, and Veterinary Anatomy, Azabu University School of Veterinary Medicine, 1-17-71 Chuo, Sagamihara, Kanagawa 252-5201, Japan
| | - Masao Asari
- Department of Toxicology, Laboratory Animal Science, and Veterinary Anatomy, Azabu University School of Veterinary Medicine, 1-17-71 Chuo, Sagamihara, Kanagawa 252-5201, Japan
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Macon MB, Fenton SE. Endocrine disruptors and the breast: early life effects and later life disease. J Mammary Gland Biol Neoplasia 2013; 18:43-61. [PMID: 23417729 PMCID: PMC3682794 DOI: 10.1007/s10911-013-9275-7] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 01/16/2013] [Indexed: 01/09/2023] Open
Abstract
Breast cancer risk has both heritable and environment/lifestyle components. The heritable component is a small contribution (5-27 %), leaving the majority of risk to environment (e.g., applied chemicals, food residues, occupational hazards, pharmaceuticals, stress) and lifestyle (e.g., physical activity, cosmetics, water source, alcohol, smoking). However, these factors are not well-defined, primarily due to the enormous number of factors to be considered. In both humans and rodent models, environmental factors that act as endocrine disrupting compounds (EDCs) have been shown to disrupt normal mammary development and lead to adverse lifelong consequences, especially when exposures occur during early life. EDCs can act directly or indirectly on mammary tissue to increase sensitivity to chemical carcinogens or enhance development of hyperplasia, beaded ducts, or tumors. Protective effects have also been reported. The mechanisms for these changes are not well understood. Environmental agents may also act as carcinogens in adult rodent models, directly causing or promoting tumor development, typically in more than one organ. Many of the environmental agents that act as EDCs and are known to affect the breast are discussed. Understanding the mechanism(s) of action for these compounds will be critical to prevent their effects on the breast in the future.
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Affiliation(s)
- Madisa B. Macon
- Curriculum in Toxicology, University of North Carolina, Chapel Hill, NC, USA
- NTP Laboratories, Division of the National Toxicology Program, NIEHS, NIH, 111 TW Alexander Dr, Bldg 101, MD E1-08, Research Triangle Park, NC 27709, USA
| | - Suzanne E. Fenton
- NTP Laboratories, Division of the National Toxicology Program, NIEHS, NIH, 111 TW Alexander Dr, Bldg 101, MD E1-08, Research Triangle Park, NC 27709, USA
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Sertoli cells proliferate in adult rats with prenatal exposure to 3,3′,4,4′,5-pentachlorobiphenyl. Arch Toxicol 2011; 86:159-62. [DOI: 10.1007/s00204-011-0736-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 07/05/2011] [Indexed: 11/27/2022]
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Wakui S, Muto T, Motohashi M, Kobayashi Y, Suzuki Y, Takahashi H, Hano H. Testicular spermiation failure in rats exposed prenatally to 3,3',4,4',5-pentachlorobiphenyl. J Toxicol Sci 2011; 35:757-65. [PMID: 20930470 DOI: 10.2131/jts.35.757] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Testicular spermatogenesis was studied in 7-, 10-, 13- and 17-week-old Sprague-Dawley rats whose dams had been administered intragastrically with 2.5, 25, or 250 ng of 3,3',4,4',5-pentachlorobiphenyl (PCB126) or vehicle on days 13-19 of gestation. The 250 ng groups among the 7-, 10- and 13-week-old offspring showed significant inhibition of mature spermatid release (spermiation), but 17-week-old offspring did not show this. These alterations were not observed in other PCB126 and vehicle groups, and no germ cell or Sertoli cell degeneration were observed in any group. Spermiation failure at puberty appeared in those rats born to dams exposed 250 ng/kg PCB126 on days 13-19 of gestation was reversible change that recovered at adulthood. Because the serum testosterone, luteinizing hormone and follicle-stimulating hormone concentrations were similar in the PCB126 and vehicle groups, a direct endocrine cause for the observed effects was unlikely.
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Hattis D, Chu M, Rahmioglu N, Goble R, Verma P, Hartman K, Kozlak M. A preliminary operational classification system for nonmutagenic modes of action for carcinogenesis. Crit Rev Toxicol 2009; 39:97-138. [PMID: 19009457 DOI: 10.1080/10408440802307467] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This article proposes a system of categories for nonmutagenic modes of action for carcinogenesis. The classification is of modes of action rather than individual carcinogens, because the same compound can affect carcinogenesis in more than one way. Basically, we categorize modes of action as: (1) co-initiation (facilitating the original mutagenic changes in stem and progenitor cells that start the cancer process) (e.g. induction of activating enzymes for other carcinogens); (2) promotion (enhancing the relative growth vs differentiation/death of initiated clones (e.g. inhibition of growth-suppressing cell-cell communication); (3) progression (enhancing the growth, malignancy, or spread of already developed tumors) (e.g. suppression of immune surveillance, hormonally mediated growth stimulation for tumors with appropriate receptors by estrogens); and (4) multiphase (e.g., "epigenetic" silencing of tumor suppressor genes). A priori, agents that act at relatively early stages in the process are expected to manifest greater relative susceptibility in early life, whereas agents that act via later stage modes will tend to show greater susceptibility for exposures later in life.
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Affiliation(s)
- D Hattis
- George Perkins Marsh Institute, Clark University, Worcester, Massachusetts, USA
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Wakui S, Akagi Y, Muto T, Yokoo K, Hirono S, Kobayashi Y, Kamei Y, Shirota K, Akahori F, Suzuki Y, Hano H, Endou H, Kanai Y. Testicular Toxicology of Pubescent and Adult Rats Prenatally Exposure to 3,3',4,4',5-Pentachlorobiphenyl. J Toxicol Pathol 2007. [DOI: 10.1293/tox.20.133] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Shin Wakui
- Department of Toxicology, Azabu University School of Veterinary Medicine
| | - Yousuke Akagi
- Department of Toxicology, Azabu University School of Veterinary Medicine
| | - Tomoko Muto
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine
| | - Kiyofumi Yokoo
- Department of Toxicology, Azabu University School of Veterinary Medicine
| | - Shyou Hirono
- Department of Toxicology, Azabu University School of Veterinary Medicine
| | - Yasuko Kobayashi
- Department of Toxicology, Azabu University School of Veterinary Medicine
| | - Yousuke Kamei
- Department of Toxicology, Azabu University School of Veterinary Medicine
| | - Kinji Shirota
- High-Tech Research Project Leaders, Azabu University
| | | | - Yoshihiko Suzuki
- Department of Biochemistry, Azabu University School of Veterinary Medicine
| | - Hiroshi Hano
- Department of Pathology, The Jikei University School of Medicine
| | - Hitoshi Endou
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine
| | - Yoshikatsu Kanai
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine
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Wakui S, Yokoo K, Takahashi H, Muto T, Suzuki Y, Kanai Y, Hano H, Furusato M, Endou H. Prenatal 3,3′,4,4′,5-pentachlorobiphenyl exposure modulates induction of rat hepatic CYP 1A1, 1B1, and AhR by 7,12-dimethylbenz[a]anthracene. Toxicol Appl Pharmacol 2006; 210:200-11. [PMID: 15990133 DOI: 10.1016/j.taap.2005.04.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2005] [Revised: 04/13/2005] [Accepted: 04/30/2005] [Indexed: 10/25/2022]
Abstract
We previously reported the finding that prenatal exposure to a relatively low dose of PCB126 increases the rate of DMBA-induced rat mammary carcinoma, while a high dose decreased it. One of the most important factors determining the sensitivity to mammary carcinogenesis is the metabolic stage at administration of the carcinogenic agent. DMBA is a procarcinogen that recruits the host metabolism to yield its ultimate carcinogenic form, and CYP1A1 and CYP1B1 (CYP1) conduct this metabolism. We investigated the hepatic expression of CYP1 and AhR following oral administration of DMBA (100 mg/kg b.w.) (i.g.) to 50-day-old female Sprague-Dawley rats whose dams had been treated (i.g.) with 2.5 ng, 250 ng, 7.5 microg of PCB126/kg or the vehicle on days 13 to 19 post-conception. Real-time quantitative RT-PCR analysis revealed that the prenatal exposure to a relatively low dose of PCB126 (the 250 ng group) prolonged the higher expression of CYP1A1, CYP1B1, and AhR mRNA, while prenatal exposure to a high dose of PCB126 (the 7.5 microg group) prolonged the higher expression of CYP1A1 and AhR mRNA. Western blotting and immunohistochemical analyses were consistent with mRNAs changes. Because DMBA oxidation produces a highly mutagenic metabolite and is finally catalyzed by CYP1B1, a relatively low PCB126 dose might produce the biological character to potentially increase the risk of DMBA-induced mammary carcinoma.
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Affiliation(s)
- Shin Wakui
- Department of Toxicologic Pathology, Azabu University School of Veterinary Medicine, 1-17-71 Fuchinobe, Kanagawa 229-8501, Japan.
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Wakui S, Yokoo K, Takahashi H, Muto T, Suzuki Y, Kanai Y, Hano H, Furusato M, Endou H. CYP1 and AhR expression in 7,12-dimethylbenz[a]anthracene-induced mammary carcinoma of rats prenatally exposed to 3,3′,4,4′,5-pentachlorobiphenyl. Toxicology 2005; 211:231-41. [PMID: 15908097 DOI: 10.1016/j.tox.2005.03.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2005] [Revised: 03/23/2005] [Accepted: 03/23/2005] [Indexed: 11/30/2022]
Abstract
We previously reported the finding that prenatal exposure to a relatively low dose of 3,3',4,4',5-pentachlorobiphenyl (PCB126) acted as an enhancing agent for 17-beta-estradiol (E2)-dependent 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat mammary carcinoma, while a high dose decreased it. E2 is a known risk factor for mammary carcinoma, and CYP1A1 and 1B1 (CYP1) are the major enzymes catalyzing 2- and 4-hydroxylation of E2, respectively. We investigated the induction of CYP1 and aryl hydrocarbon receptor (AhR) in DMBA-induced mammary carcinoma using female Sprague-Dawley rats whose dams had been treated (i.g.) with 2.5 ng, 250 ng, 7.5 microg of PCB126/kg or the vehicle on days 13-19 post-conception. Immunohistochemical analysis revealed that the mammary carcinoma of the 250 ng group showed a significantly higher number of nuclei expressing estrogen receptor alpha (ER) and proliferating cell nuclear antigen (PCNA) compared to those of the other groups. Quantitative real-time RT-PCR analysis revealed that the 7.5 microg group showed a significantly higher level of CYP1A1 mRNA, and that the 250 ng group showed significantly higher levels of CYP1B1 mRNA. The level of AhR mRNA was significantly higher in both the 7.5 microg and 250 ng groups. Western blotting analysis was consistent with mRNA changes. It has been revealed that CYP1B1 catalyzes a step in the formation of 4-hydroxylated E2 metabolites, which show quite high mammary carcinogenicity. This study indicates that the enhancement of DMBA-induced mammary carcinogenicity in a relatively low PCB126 dose group might partially involve the higher expression of CYP1B1 and AhR in these carcinomas.
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MESH Headings
- 9,10-Dimethyl-1,2-benzanthracene
- Adenocarcinoma/chemically induced
- Adenocarcinoma/enzymology
- Adenocarcinoma/metabolism
- Adenocarcinoma/pathology
- Animals
- Aryl Hydrocarbon Hydroxylases/biosynthesis
- Aryl Hydrocarbon Hydroxylases/genetics
- Blotting, Western
- Body Weight/drug effects
- Carcinogens, Environmental/toxicity
- Cytochrome P-450 CYP1A1/biosynthesis
- Cytochrome P-450 CYP1A1/genetics
- Cytochrome P-450 CYP1B1
- Female
- Immunohistochemistry
- Male
- Mammary Neoplasms, Experimental/chemically induced
- Mammary Neoplasms, Experimental/enzymology
- Mammary Neoplasms, Experimental/metabolism
- Mammary Neoplasms, Experimental/pathology
- Organ Size/drug effects
- Polychlorinated Biphenyls/toxicity
- Pregnancy
- Prenatal Exposure Delayed Effects
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Rats
- Receptors, Aryl Hydrocarbon/biosynthesis
- Receptors, Aryl Hydrocarbon/genetics
- Receptors, Aryl Hydrocarbon/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
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Affiliation(s)
- Shin Wakui
- Department of Toxicologic Pathology, Azabu University School of Veterinary Medicine, Kanagawa 229-8501, Japan.
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Muto T, Watanabe T, Moto M, Okamura M, Kashida Y, Kanai Y, Mitsumori K, Endou H. Time Course of Expression of 7,12-Dimethylbenz[a]anthracene-induced CYP1A1 and CYP1B1 mRNA and Protein in Rat Liver. J Toxicol Pathol 2003. [DOI: 10.1293/tox.16.287] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Tomoko Muto
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine
| | - Takao Watanabe
- Laboratory of Veterinary Pathology, Faculty of Agriculture, Tokyo University of Agriculture and Technology
| | - Mitsuyoshi Moto
- Laboratory of Veterinary Pathology, Faculty of Agriculture, Tokyo University of Agriculture and Technology
| | - Miwa Okamura
- Laboratory of Veterinary Pathology, Faculty of Agriculture, Tokyo University of Agriculture and Technology
| | - Youko Kashida
- Laboratory of Veterinary Pathology, Faculty of Agriculture, Tokyo University of Agriculture and Technology
| | - Yoshikatsu Kanai
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine
| | - Kunitoshi Mitsumori
- Laboratory of Veterinary Pathology, Faculty of Agriculture, Tokyo University of Agriculture and Technology
| | - Hitoshi Endou
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine
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Muto T, Wakui S, Imano N, Nakaaki K, Takahashi H, Hano H, Furusato M, Masaoka T. Mammary gland differentiation in female rats after prenatal exposure to 3,3',4,4',5-pentachlorobiphenyl. Toxicology 2002; 177:197-205. [PMID: 12135623 DOI: 10.1016/s0300-483x(02)00224-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recently we reported finding that prenatal exposure to a relatively low dose of 3,3',4,4',5-pentachlorobiphenyl (PCB126) increases the rate of 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary carcinoma, while a high dose decreases it. One of the most important factors determining sensitivity of the mammary gland to neoplastic stimuli is its stage of differentiation at the time of exposure to the carcinogenic agent. Hence, to verify a biphasic dose-response relationship (enhancement of carcinogenesis at low dose, and inhibition at high dose), we investigated the effects of prenatal exposure to PCB126 on mammary gland differentiation. Female SD rats were injected (i.g.) with 25 pg, 2.5 ng, 250 ng, 7.5 microg of PCB126/kg, or the vehicle, on days 13-19 postconception. In 50-day-old offspring, regardless of the day of exposure to DMBA, only the 7.5 microg group showed statistically significant high levels of PCB126 in the fatty tissue of their mammary glands. Fifty-day-old female offspring of the 250 ng group showed apparent inhibition of the normal differentiation of terminal end buds (TEB) to alveolar buds and lobules (ABL), while those of the 7.5 microg group showed mammary gland hypoplasia. Expression levels of the estrogen receptor-alpha (ER) in TEBs and the ER mRNA in mammary glands were higher in the 7.5 microg, 250 ng, 2.5 ng groups. Proliferating cell nuclear antigen (PCNA) expression in TEBs of 50-day-old rats was statistically significantly higher in the 250 ng group and lower in the 7.5 microg group. In the developing mammary gland, TEBs are considered the most susceptible to mammary carcinogenesis, while ABLs are relatively protected from mammary carcinogenesis. Thus, prenatal exposure to a relatively low dose of PCB126 induced an alteration of mammary gland differentiation that might potentially increase the risk of DMBA-induced mammary carcinoma.
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Affiliation(s)
- Tomoko Muto
- Department of Pathology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan
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