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1.
Int J Cancer ; 121(3): 514-9, 2007 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-17397026

RESUMO

The abundance of fat tissue surrounding normal and malignant epithelial mammary cells raises the questions whether such "adipose milieu" is important in the local proinflammatory/genotoxic shift, which apparently promotes tumor development and worsens prognosis, and what conditions stimulate this shift, or "adipogenotoxicosis." We studied 95 mammary fat samples from 70 postmenopausal and 25 premenopausal breast cancer (BC) patients at a distance of 1.5-2.0 cm from tumors. The levels of leptin, adiponectin, TNFalpha and IL-6 release after 4-hr incubation of the samples were evaluated with ELISA, nitric oxide (NO) production by Griess reaction and lipid peroxidation by determination of thiobarbiturate-reactive products (TBRP). Infiltration of fat with macrophages (CD68-positive cells) and expression of cytochrome P450 1B1/estrogen 4-hydroxylase (CYP1B1) were detected by immunohistochemistry. Aromatase (CYP19) activity in mammary fat was measured by (3)H(2)O release from (3)H-1beta-androstenedione. In the postmenopausal BC patients, NO and TNFalpha production by adipose tissue explants increased independent of BMI and in parallel with decreasing leptin and, especially, adiponectin release. In the premenopausal patients, higher CYP1B1 expression and TBRP level were found in mammary fat, while higher aromatase activity was combined with higher CYP1B1 expression as well as NO and IL-6 production. In the postmenopausal group, impaired glucose tolerance was associated with higher IL-6 release production by fat and with higher IL-6/adiponectin ratio. Thus, signs of adipogenotoxicosis in mammary fat can be found in both pre- and postmenopausal BC patients. This condition is likely being maintained through estrogen- and glucose-related factors and mechanisms presumably associated with less favorable types of hormonal carcinogenesis.


Assuntos
Tecido Adiposo/fisiologia , Neoplasias da Mama/patologia , Estrogênios/fisiologia , Hiperglicemia/patologia , Glândulas Mamárias Humanas/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Aromatase/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Feminino , Humanos , Inflamação/patologia , Leptina/metabolismo , Macrófagos/patologia , Pessoa de Meia-Idade , Pós-Menopausa , Pré-Menopausa
2.
Ann N Y Acad Sci ; 1057: 235-46, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16399898

RESUMO

Estrogens and glucose are characterized by a myriad of functions that can be reduced to a small number of principal actions. In aging there is a simultaneous increase in the prevalence of diseases connected with estrogen deficiency as well as with estrogenic excess and associated with the phenomenon of the switching of estrogen effects (PSEE). Estrogens possess hormonal and genotoxic properties. An increase in genotoxic effect (isolated or combined with a decrease in hormonal effect) can influence the course of age-associated diseases that, contrary to the situation with adaptive hypersensitivity to estrogens, may become less favorable or more aggressive. Inductors of PSEE include smoking, irradiation, and aging. Yet with "glycemic load" and the endocrine effect of glucose (the stimulation of insulin secretion), reactive oxygen species are formed in multiple sites, including adipose tissue. The ratio between hormonal and genotoxic effects reflects a "joker" function of glucose and can be conditioned by endogenous (perhaps including genetic) and exogenous factors. The shift in this glucose-associated ratio may selectively encourage some chronic non-communicable diseases. Several groups of treatments can be distinguished including alleviators of PSEE and insulin resistance syndrome (biguanides, glitazones, statins, modifiers of adipocytokines secretion, etc.) as well as other compounds aimed to optimally orchestrate the balance between endocrine and DNA-damaging effects of estrogens and glucose.


Assuntos
Envelhecimento/fisiologia , Estrogênios/metabolismo , Glucose/metabolismo , Tecido Adiposo/metabolismo , Animais , Receptor alfa de Estrogênio/metabolismo , Estrogênios/toxicidade , Feminino , Glucose/toxicidade , Humanos , Resistência à Insulina , Camundongos
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