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Postnatal exposure to Bisphenol A in females with gestational protein restriction: effects on breast development and susceptibility to carcinogenesis

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Muriele Bertagna Varuzza
Total Authors: 1
Document type: Master's Dissertation
Press: Botucatu. 2018-03-05.
Institution: Universidade Estadual Paulista (Unesp). Faculdade de Medicina. Botucatu
Defense date:
Advisor: Luis Fernando Barbisan

Disturbances in the uterine environment and in the early stages of life, due to nutritional factors and/or hormonal changes, may predispose newborns to chronic diseases in adult life. Gestational protein restriction (GPR) and exposure to Bisphenol A (BPA), in the pre and postnatal phases alter breast development and increase susceptibility to mammary carcinogenesis. Therefore, the aim of this study was to investigate the possible effects of GPR and its association with postnatal exposure to BPA on mammary gland development and on susceptibility to 7,12-dimethylbenzanthracene (DMBA) induced mammary carcinogenesis. For this purpose, pregnant females of the Sprague-Dawley strain were allocated into four experimental groups: normoprotein diet (NPD); hypoproteic diet (HPD); NPD+BPA and HPD+BPA. BPA (1 mg/L) was given in drinking water to offspring from postnatal day (PND) 21 to PND 51. At the PDN 51, offspring females (n=10/group) were euthanized for mammary glands evaluation, while the remainder (n=11/group) received a single dose of DMBA (30 mg/kg, ig) and were euthanized at the PND 250 for breast tumors evaluation. GPR and BPA exposure did not alter the growth of the mammary tree, number of bud and terminal duct (TEBs and TDs), cell proliferation (Ki-67), expression of estrogen receptor β (ER-β) and collagen fibers area in the mammary glands at PDN 51. However, in the HPD and NPD+BPA groups was a decreased area corresponding to the glandular epithelial tissue and the association (HPD+BPA) increased the fat pad. Exposure to BPA (NPD+BPA and HPD+BPA) increased apoptotic indexes, GPR increased estrogen receptors α expression (ER-α) while their association (HPD+BPA) increased progesterone receptors (PR) in the mammary glands. The groups HPD, NPD+BPA and HPD+BPA also showed lower tumor latency. In addition, the groups that received BPA presented higher tumor incidence and multiplicity. These results suggests that GPR and BPA exposure increased the susceptibility to mammary carcinogenesis induced by DMBA, but the association (HPD+BPA) did not increase the risk. (AU)

FAPESP's process: 16/01220-2 - Postnatal exposure to bisphenol A in females with gestational protein restriction: effects on breast development and susceptibility to carcinogenesis
Grantee:Muriele Bertagna Varuzza
Support Opportunities: Scholarships in Brazil - Master