28 research outputs found

    Alterations in Vitamin D signalling and metabolic pathways in breast cancer progression: a study of VDR, CYP27B1 and CYP24A1 expression in benign and malignant breast lesions Vitamin D pathways unbalanced in breast lesions

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    <p>Abstract</p> <p>Background</p> <p>Breast cancer is a heterogeneous disease associated with different patient prognosis and responses to therapy. Vitamin D has been emerging as a potential treatment for cancer, as it has been demonstrated that it modulates proliferation, apoptosis, invasion and metastasis, among others. It acts mostly through the Vitamin D receptor (VDR) and the synthesis and degradation of this hormone are regulated by the enzymes CYP27B1 and CYP24A1, respectively. We aimed to study the expression of these three proteins by immunohistochemistry in a series of breast lesions.</p> <p>Methods</p> <p>We have used a cohort comprising normal breast, benign mammary lesions, carcinomas <it>in situ </it>and invasive carcinomas and assessed the expression of the VDR, CYP27B1 and CYP24A1 by immunohistochemistry.</p> <p>Results</p> <p>The results that we have obtained show that all proteins are expressed in the various breast tissues, although at different amounts. The VDR was frequently expressed in benign lesions (93.5%) and its levels of expression were diminished in invasive tumours (56.2%). Additionally, the VDR was strongly associated with the oestrogen receptor positivity in breast carcinomas. CYP27B1 expression is slightly lower in invasive carcinomas (44.6%) than in benign lesions (55.8%). In contrast, CYP24A1 expression was augmented in carcinomas (56.0% in <it>in situ </it>and 53.7% in invasive carcinomas) when compared with that in benign lesions (19.0%).</p> <p>Conclusions</p> <p>From this study, we conclude that there is a deregulation of the Vitamin D signalling and metabolic pathways in breast cancer, favouring tumour progression. Thus, during mammary malignant transformation, tumour cells lose their ability to synthesize the active form of Vitamin D and respond to VDR-mediated Vitamin D effects, while increasing their ability to degrade this hormone.</p

    Brazilian Consensus on Photoprotection

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    Brazil is a country of continental dimensions with a large heterogeneity of climates and massive mixing of the population. Almost the entire national territory is located between the Equator and the Tropic of Capricorn, and the Earth axial tilt to the south certainly makes Brazil one of the countries of the world with greater extent of land in proximity to the sun. The Brazilian coastline, where most of its population lives, is more than 8,500 km long. Due to geographic characteristics and cultural trends, Brazilians are among the peoples with the highest annual exposure to the sun. Epidemiological data show a continuing increase in the incidence of nonmelanoma and melanoma skin cancers. Photoprotection can be understood as a set of measures aimed at reducing sun exposure and at preventing the development of acute and chronic actinic damage. Due to the peculiarities of Brazilian territory and culture, it would not be advisable to replicate the concepts of photoprotection from other developed countries, places with completely different climates and populations. Thus the Brazilian Society of Dermatology has developed the Brazilian Consensus on Photoprotection, the first official document on photoprotection developed in Brazil for Brazilians, with recommendations on matters involving photoprotection

    Serum level of under-carboxylated osteocalcin and bone mineral density in early menopausal Norwegian women

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    Purpose: Serum level of under-carboxylated osteocalcin (ucOC) is considered a sensitive measure of vitamin K status, and ucOC levels are associated with bone mineral density (BMD) and fracture risk in elderly persons. The aim of this study was to assess the relationship between ucOC and BMD in early menopausal women. Methods: The data reported here come from the enrolment in a double-blinded placebo-controlled randomized trial comprising 334 healthy Norwegian women between 50 and 60 years, 1-5 years after menopause, not using warfarin or medication known to affect bone metabolism. Total hip, femoral neck, lumbar spine, and total body BMD and serum level of ucOC and total osteocalcin were measured, and information of lifestyle was collected through questionnaires. The association between ucOC and BMD at all measurement sites was assessed by multiple regression analyses adjusting for possible confounding variables. Results: The absolute serum level of ucOC was significantly and negatively associated with BMD at all measurements sites, both in univariate analyses (p < 0.01) and in multivariate analyses adjusting for years since menopause, smoking status and weight (p < 0.01). However, serum ucOC, expressed as percentage of the total osteocalcin level, was not associated with BMD at any site. Conclusions: Achievement of adequate vitamin K nutritional intake is important, but ucOC expressed as percentage of total osteocalcin levels as reflection of vitamin K status does not seem to play a central role in determining BMD levels in early menopausal women. © 2011 Springer-Verlag
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