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Mammary Cancer (mammary + cancer)
Selected AbstractsThe contribution of hepatic steroid metabolism to serum estradiol and estriol concentrations in nonylphenol treated MMTVneu mice and its potential effects on breast cancer incidence and latencyJOURNAL OF APPLIED TOXICOLOGY, Issue 5 2005Ricardo Acevedo Abstract The two major pathways for the metabolism of estradiol-17, (E2) are the 2- and 16-hydroxylase pathways. Research has suggested that the increased production of the estrogenically active 16-hydroxy products such as estriol (E3) may be involved in increased susceptibility to breast cancer. 4-Nonylphenol (4-NP) is an environmental estrogen that also can activate the pregnane-X receptor (PXR) and induce P-450 enzymes responsible for the production of E3. It is hypothesized that 4-NP may act in part as an environmental estrogen by increasing E3 production. Based on its affinity for the estrogen receptor (ER) alone, 4-NP may be more potent than predicted at increasing mammary cancer incidence in the MMTVneu mouse. Female mice were treated per os for 7 days at 0, 25, 50 or 75 mg kg,1 day,1 4-NP to investigate the effects of 4-NP on hepatic estrogen metabolism after an acute treatment. 4-Nonylphenol increased the hepatic formation of E3 in a dose-dependent manner. However, serum E3 concentrations were only increased at 25 mg kg,1 day,1 presumably due to direct inhibition of E3 formation by 4-NP. MMTVneu mice were then treated for 32 weeks at 0, 30 or 45 mg kg,1 day,1 4-NP to determine its effects on mammary cancer formation and estrogen metabolism. 4-Nonylphenol increased mammary cancer formation in the MMTVneu mice at 45 mg kg,1 day,1 but not at 30 mg kg,1 day,1. Mice treated with an equipotent dose of E2, 10 µg kg,1 day,1, based on the relative binding affinities of nonylphenol and estradiol for ER,, did not develop mammary cancer. This suggests that nonylphenol is more potent than predicted based on its affinity for the estrogen receptor. However, no changes in serum E3 concentrations or hepatic E3 production were measured after the chronic treatment. Changes in E3 formation were correlated with increased CYP2B levels after the 7 day 4-NP treatment, and repression of CYP2B and CYP3A after 32 weeks of 4-NP treatment. Microarray analysis and Q-PCR of liver mRNA from the mice treated for 32 weeks demonstrated a decrease in RXR,, the heterodimeric partner of the PXR, which may in part explain the repressed transcription of the P450s measured. In conclusion, 4-NP treatment for 32 weeks increased mammary cancer formation at a dose of 45 mg kg,1 day,1. However, chronic treatment with 4-NP did not increase hepatic E3 formation or serum E3 concentrations. The transient induction by 4-NP of hepatic E3 formation and serum concentrations is most likely not involved in the increased incidence of mammary cancer in MMTVneu mice since E3 serum concentrations were only increased at 25 mg kg,1 day,1, a dose that was not sufficient to induce mammary tumor formation. Nevertheless, the induced hepatic E3 production in the acute exposures to 4-NP was indicative of an increase in mammary cancer incidence after the chronic exposure. Copyright © 2005 John Wiley & Sons, Ltd. [source] Topical superoxide dismutase reduces post-irradiation breast cancer fibrosisJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 1 2004F. Campana Abstract Fibrosis following breast radiotherapy for mammary cancer is a frequent undesired effect with objective (esthetic) and subjective (pain) consequences. Forty-four patients with clinical radiofibrosis following conservative treatment of breast cancer were evaluated for the local antifibrosis effect of copper zinc superoxide dismutase [SOD(Cu/Zn)]. Extracted SOD(Cu/Zn) in a concentration of 3,600 units/mg was applied as ointment to the fibrotic affected area, b.i.d. for 90 days, in a total dose of 40 mg. The radiofibrosis intensity was scored on the basis of clinical criteria (pain and the fibrosis area) before and after SOD(Cu/Zn) treatment. SOD(Cu/Zn) was found to be effective in reducing radiation induced fibrosis by a lowering pain score in 36/39 patients and a decrease of the fibrotic area size in half cases, after 6 months. The intensity and changes of breast fibrosis were assessed also by mammography and, for the topographical distribution of subcutaneous temperature, by infrared thermography. Mammography density suggested decreased fibrosis in one third of patients. Thermography showed that fibrosis was accompanied by two zones clinically indistinctive: a central area with maximum thermal activity, called "Maximal Thermic zone" (MTZ) and a peripheral area with less thermal activity but higher than in the surrounding normal tissue, "Transitional Thermic Zone" (TTZ). Both MTZ and TTZ were significantly decreased in 36/44 patients after SOD(Cu/Zn) treatment. Clinical changes persisted all along the study. Treatment was well tolerated except for one case of local allergic reaction, and no important side effects. Molecular mechanisms involved are discussed. Further studies are running to confirm and explain these results. [source] Association between Waste Management and Cancer in Companion AnimalsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 3 2009L. Marconato Background: Increased cancer rates have been documented in people residing in areas around Naples characterized by illegal dumping and incineration of waste. Hypothesis: Risk of cancer in dogs and cats is associated with waste management. Animals: Four hundred and fifty-three dogs and cats with cancer and 1,554 cancer-free animals. Methods: Hospital-based case-control study in Naples (low danger) and nearby cities having a history of illegal waste dumping (high danger). Odds ratio (OR) between high- and low-danger areas was calculated for all tumors and various malignancies in dogs and cats. Results: An increased risk for cancer development was identified in dogs but not in cats residing in high-danger areas (OR: 1.55; 95% confidence interval: 1.18,2.03; P < .01). A 2.39-fold increased risk of lymphoma (P < .01) accounted for the greater tumor frequency in dogs residing in high-danger areas. The risk of mast cell tumor and mammary cancer did not differ in dogs residing in high- or low-danger areas. Conclusions and Clinical Importance: Waste emission from illegal dumping sites increases cancer risk in dogs residing in high-danger areas. An increased prevalence of lymphoma has been previously recognized in humans living close to illegal waste dumps. Thus, epidemiological studies of spontaneous tumors in dogs might suggest a role for environmental factors in canine and human carcinogenesis and can predict health hazards for humans. [source] Role of dietary lignans in the reduction of breast cancer riskMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 7 2007Niina M. Saarinen Abstract Lignans are a large group of fiber-associated phenolic compounds widely distributed in edible plants. Some of the ingested plant lignans are converted by intestinal microbiota to enterolignans, enterodiol (END) and enterolactone (ENL), the latter of which has been thought to be the major biologically active lignan, and suggested to be associated with low risk of breast cancer. In line with this, administration of plant lignans which are further metabolized to ENL, or ENL as such, have been shown to inhibit or delay the growth of experimental mammary cancer. The mechanism of anticarcinogenic action of ENL is not yet fully understood, but there is intriguing evidence for ENL as a modulator of estrogen signaling. These findings have generated interest in the use of lignans as components of breast cancer risk reducing functional foods. Identification of target groups, who would benefit most, is of pivotal importance. Therefore, further identification and validation of relevant biomarkers, which can be used as indicators of lignan or ENL action and breast cancer risk reduction at different stages of the disease, are of importance. [source] | ||||||||||