Puslapis 1 nuo 23 rezultatus
The breast cancer resistance protein (BCRP/ABCG2) usually protects the body from a wide variety of environmental and dietary xenotoxins by reducing their net uptake from intestine and by increasing their hepatobiliary, intestinal and renal elimination. BCRP is also highly expressed in lactating
Aflatoxin B1 (AFB1), a mycotoxin produced by Aspergillus spp., was proved as one of the major causes of human hepatocellular carcinoma (HCC) when chronically consumed. An efflux of AFB1 was reported to be associated with breast cancer resistance protein (BCRP)
Zearalenone (ZEA) has long been recognized as a xenoestrogen, while the endocrine disrupting effects of aflatoxin B1 (AFB1) have been identified recently. Due to co-occurrence and endocrine disrupting potentials of ZEA and AFB1, it was hypothesized that co-exposure to ZEA and AFB1 might affect
Cytochrome P450 3A4 (CYP3A4), a member of multigene superfamily of enzymes, plays a major role in the activation of procarcinogens such as polycyclic hydrocarbon dihydrodiols, aflatoxins and heterocyclic amines as well as of several drugs including tamoxifen which is used in breast cancer therapy.
Dehydroepiandrosterone, an adrenal steroid that has been reported to be produced in subnormal amounts and found in lower plasma concentrations in women with benign and malignant breast tumors, protects cultured rat liver epithelial-like cells against aflatoxin B1-induced cytotoxicity and protects
The direct and transplacental action of aflatoxin B1 was studied on organic cultures of the embryonic pulmonary tissue of mice of the A line, BD-IX rats and golden hamsters (Cricetus auratus W.). Its toxic action on the cultures and the absence of any blastomogenic effect was demonstrated. In
A mammalian cell expression plasmid containing cytochrome P450IIIA7 complementary DNA was constructed. Breast cancer cells (MCF-7) were transfected with the plasmid and neomycin-resistant selection marker plasmid. We established three cell lines, termed M13, M21, and M27, which expressed the
Recent clinical trials suggest that tamoxifen (TAM) is a preventive agent for breast cancer, however, the mechanism is unknown. Previously, we found that both 17beta-estradiol (E2) and estrone (E1) could be activated by epoxidation resulting in their ability to bind to DNA, forming DNA adducts both
Epidemiological and animal studies have indicated that 17beta-estradiol (E2) is involved in breast cancer; however, the mechanism is unclear. We found that E2 could be activated by epoxidation, resulting in its ability to inhibit nuclear DNA-dependent RNA synthesis, and to bind DNA, forming DNA
Descriptive epidemiology, particularly regarding the cancer pattern in Japanese and Koreans in the United States, indicates that lifestyle factors contribute substantially to the development of common cancers such as gastric, colorectal, breast and prostate cancers. Sex and age are important
AR42J-B-13 (B-13) cells form hepatocyte-like (B-13/H) cells in response to glucocorticoid treatment. To establish its utility in toxicity and genotoxicity screening, cytochrome P450 (CYP) induction, susceptibility to toxins, and transporter gene expression were examined. Conversion to B-13/H cells
Dietary factors including obesity and physical activity are estimated to account for approximately 35% of cancer death in the United States. According to the WHO/FAO report in 2003 based on a review of published epidemiological studies, convincing evidence between diet-related factors and cancer are
A regulator of the protein phosphatase 2A (PP2A), α4, has been implicated in a variety of functions that regulate many cellular processes. To explore the role of α4 in human cell transformation and tumorigenesis, we show that α4 is highly expressed in human cells transformed by chemical carcinogens
Despite an increasing incidence of human breast cancer, its etiology remains unknown. Since some environmental chemicals are stored in human breast fat and are rodent mammary carcinogens, determining the genotoxic potential of environmental agents in this key target tissue is important. An assay was
The past four decades of epidemiological research have yielded valuable information on the risks of populations to environmental exposures such as tobacco, asbestos, and dietary components. Prevention efforts have been focused on large-scale population-based interventions to minimize exposure to