No description available.

Vitamin D is central in calcium turnover, and adequate levels are important for skeletal health. It is not clear how large contributions from food and sunlight are in Swedish primary care patients, considering the low radiation of UVB in Sweden and fortification of some foods, and whether differences exist between patients of immigrant and Swedish origin. Increasing incidence of osteoporosis-related fractures is a major global health problem. Genetic variations in metabolising enzymes and in the Vitamin D receptor (VDR) have also been shown to be of importance to the overall effect of vitamin D. Polymorphic variation in the gene CYP2R1 encoding the 25-hydroxylase has previously been reported to correlate with circulating levels of 25(OH)D3. Results of association studies between genetic variants of the VDR and muscle strength, as well as falls have been contradictory. The purposes of this thesis were to examine possible differences in plasma-25(OH)D3 levels and intake of vitamin D between Swedish and immigrant female primary care patients, to estimate what foods contribute the most, and to identify contributors to vitamin D status (Paper I-II). Furthermore, the relationship between polymorphisms in the CYP2R1 gene and levels of 25(OH)D3 as well as other biochemical parameters (parathyroid hormone, calcium, phosphate and fibroblast growth factor 23) of skeletal homeostasis, bone mineral density and incidence of fractures was investigated (Paper III). Also, the association between genetic variations in the gene for the vitamin D receptor and measures of muscle strength, physical performance and falls (Paper IV), was investigated by using data from a Swedish multicenter study of elderly men (MrOS). Most important results: Vitamin D deficiency was common, with significant difference between Swedish born and immigrant patients (Paper I). Food intake of vitamin D is associated with circulating vitamin D, but the factors most strongly affecting vitamin D levels were reported sun holiday and origin (Paper II). CYP2R1 polymorphisms are associated with circulating levels of 25(OH)D3 and bone mineral density (Paper III). VDR genetic variants do not appear to have a direct effect on muscle strength or physical performance and incidence of falls in elderly Swedish men (Paper IV).

<p>Correa, P. 2002. Vitamin D and its receptor in parathyroid tumors. Acta Universitatis Upsaliensis. Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine 1186. 49 pp. Uppsala. ISBN 91-554-541-0 </p><p>Hyperparathyroidism (HPT) is characterized by tumor development in the parathyroid glands and excessive production of parathyroid hormone. Parathyroidectomy is the only considered therapy for the majority of patients. </p><p>LOH (loss of heterozygosity) analysis revealed putative tumor suppressor genes on chromosome regions 1p and 11q in tumors from patients with truly mild hypercalcemia.</p><p>Active vitamin D [1,25(OH)2D3] and its receptors, the vitamin D receptor (VDR), are essential regulators of the calcium homeostasis and are involved in HPT development. The VDR-FokI polymorphism, coupled to bone mineral density, was found not to be associated to development of primary HPT (pHPT). The total VDR mRNA levels is reduced in adenomas of pHPT as well as in hyperplastic glands of secondary HPT (sHPT). The VDR exon 1f transcripts were exclusively downregulated in the adenomas of pHPT, suggesting default regulation of the tissue-specially expressed VDR 1f promoter. The cytochrome P450 enzymes responsible for synthesis and degradation of 1,25(OH)2D3, namely vitamin D3 25-hydroxylase (25-hydroxylase), 25-hydroxyvitamin D3 1a-hydroxylase (1a-hydroxylase) and 25-hydroxyvitamin D3 24-hydroxylase (24-hydroxylase) were found to be expressed in normal and pathological parathyroid glands. Tumors of pHPT and sHPT demonstrated increased 1a-hydroxylase and reduced 24- and 25-hydroxylase expression, suggesting an augmented local production of active vitamin D. In contrast, parathyroid carcinomas displayed reduced expression of all three hydroxylases. The gained knowledge of vitamin D metabolism and catabolism in parathyroid tumors may indicate possibilities for novel treatment of sHPT and perhaps pHPT.</p>

Correa, P. 2002. Vitamin D and its receptor in parathyroid tumors. Acta Universitatis Upsaliensis. Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine 1186. 49 pp. Uppsala. ISBN 91-554-541-0 Hyperparathyroidism (HPT) is characterized by tumor development in the parathyroid glands and excessive production of parathyroid hormone. Parathyroidectomy is the only considered therapy for the majority of patients. LOH (loss of heterozygosity) analysis revealed putative tumor suppressor genes on chromosome regions 1p and 11q in tumors from patients with truly mild hypercalcemia. Active vitamin D [1,25(OH)2D3] and its receptors, the vitamin D receptor (VDR), are essential regulators of the calcium homeostasis and are involved in HPT development. The VDR-FokI polymorphism, coupled to bone mineral density, was found not to be associated to development of primary HPT (pHPT). The total VDR mRNA levels is reduced in adenomas of pHPT as well as in hyperplastic glands of secondary HPT (sHPT). The VDR exon 1f transcripts were exclusively downregulated in the adenomas of pHPT, suggesting default regulation of the tissue-specially expressed VDR 1f promoter. The cytochrome P450 enzymes responsible for synthesis and degradation of 1,25(OH)2D3, namely vitamin D3 25-hydroxylase (25-hydroxylase), 25-hydroxyvitamin D3 1a-hydroxylase (1a-hydroxylase) and 25-hydroxyvitamin D3 24-hydroxylase (24-hydroxylase) were found to be expressed in normal and pathological parathyroid glands. Tumors of pHPT and sHPT demonstrated increased 1a-hydroxylase and reduced 24- and 25-hydroxylase expression, suggesting an augmented local production of active vitamin D. In contrast, parathyroid carcinomas displayed reduced expression of all three hydroxylases. The gained knowledge of vitamin D metabolism and catabolism in parathyroid tumors may indicate possibilities for novel treatment of sHPT and perhaps pHPT.

No description available.

No description available.

O melanoma é uma lesão maligna da pele, com alta taxa de mortalidade cuja incidência vem aumentando nos últimos anos. Os principais fatores de risco são a história familial da doença, presença de nevos benignos múltiplos ou nevos atípicos e melanoma prévio. Imunossupressão, sensibilidade ao sol e exposição intermitente e intensa à radiação UV da luz solar, sem proteção, são fatores de risco adicionais. O objetivo deste estudo caso-controle de base hospitalar foi avaliar a contribuição de polimorfismos de genes de metabolização de xenobióticos (CYP1A1/MspI, CYP2E1/PstI, GSTM1, GSTT1 e GSTP1/Bsma), de genes de reparo do DNA (XRCC1/MspI, XRCC3/NcoI e XPD/PstI) e do gene do receptor de vitamina D (VDR/FokI e VDR/TaqI) no risco de melanoma. Consentiram em participar 193 pacientes com melanoma (49,7% homens e 50,3% mulheres, média de 52 ± 14,28 anos) e 208 controles (51,4% homens e 48,6% mulheres, média de 48 ± 15,24 anos) que após responderem a um questionário detalhado sobre hábitos e tipos de exposição a fatores de risco cederam amostras biológicas para análsie do DNA por PCR-RFLP. Os principais fatores de risco para o melanoma foram ascendência européia (p<0,001), cor de olhos claros (p<0,001), presença de nevos (p<0,001), histórico de queimadura grave na adolescência (p<0,001), falta de filtro solar (p<0.034) e exposição à lâmpadas fluorescentes (p=0,001). Quanto à análise dos polimorfismos de genes de metabolização de xenobióticos somente o GSTT1 nulo revelou associação inversamente positiva com o risco de melanoma maligno (OR ajustado = 0,60; IC95% = 0,37-0,97). Entretanto, essa associação não se manteve após a análise de regressão múltipla escalonada. Os polimorfismos VDR/FokI e VDR/TaqI não modificaram a susceptibilidade ao melanoma maligno na comparação entre os grupos. Na análise conjunta do fenótipo-genótipo, indivíduos com olhos verdes e genótipo VDR/FokI polimórfico, apresentaram risco praticamente seis vezes maior de melanoma (OR ajustado = 5,93; IC95% = 1,49-23,59). A associação entre os polimorfismos em pelo menos um dos alelos dos genes de reparo do DNA, XRCC3/NcoI e XPD/PstI aumentou praticamente duas vezes o risco de melanoma tanto na análise estatística multivariada (OR ajustado = 1,84; IC95% = 1,08-3,14) quanto na regressão logística múltipla escalonada (OR ajustado = 2,32; IC95% = 1,01-5,36). Na interação genemeio ambiente a falta do uso de filtro solar dobrou o risco de melanoma em indivíduos com polimorfismo XPD/PstI (OR ajustado = 2,17; IC95% = 1,12- 4,17). A identificação de polimorfismos genéticos associados com doenças multifatorias como o caso do melanoma maligno devem ser estimuladas em nosso meio, principalmente por vivermos em um país tropical com alta incidência solar em praticamente todo seu território. A identificação de marcadores genéticos de susceptibilidade pode propiciar medidas precoces e eficazes de prevenção do câncer. / Melanoma is a malignant skin lesion, with high mortalitty rate and its incidence has been rising in the last years. The main risk factors are melanoma family history, presence of multiple benign or atypical nevi and previous melanoma. Immunosuppression, sun sensitivy and intermittent and intense exposure to UV sunlight radiation, without protection, are additional risk factors. The aim of this hospital based case-control study was to evaluate the contribution of genetic polymorphisms of xenobiotic metabolizing enzymes (CYP1A1/MspI, CYP2E1/PstI, GSTM1, GSTT1 and GSTP1/Bsma), DNA repair genes (XRCC1/MspI, XRCC3/NcoI and XPD/PstI) and vitamin D receptor genes (VDR/FokI and VDR/TaqI) to the risk of melanoma. All participants, including 193 melanoma patients (49.7% men and 50.3% women, mean age 52 ± 14.28 years old) and 208 controls (51.4% men and 48.6% women, mean age 48 ± 15.24 years old) gave written informed consent to participate in the study and agreed to donate a sample of bloody to analysis of DNA by PCR-RFLP and answer a questionarie regarding phenotypic characteristics, personal habits and questions regarding sun exposure that could be associated to the disease. The main risk factors to melanoma were European ancestries (p<0.001), light colored eyes (p<0.001), presence of nevi (p<0.001), history of sunburns during the adolescence (p<0.001), no use of sunblock (p<0.034) and exposure of fluorescent lamps (p<0.001). Regarding the genes polymorphisms, only GSTT1 null genotype showed as an inversely positivefactor (OR adjusted = 0.60; 95%CI = 0.37-0.97) to malignant melanoma. However, this association disappeared with multiple regression analysis. The VDR/FokI and VDR/TaqI polymorphisms did not alter the susceptibility to malignant melanoma in the comparison between groups. A joint analysis of phenotype-genotype, individuals with green eyes and polymorphic genotype VDR/FokI, presented almost six times more risk to melanoma (OR adjusted = 5.93, 95% CI = 1.49-23.59). The association between polymorphisms, in at least one polymorphic allele of DNA repair genes XRCC3/NcoI and XPD/PstI increased almost twice the risk of melanoma in the multivariate statistic analysis (OR adjusted = 1.84, 95%CI = 1.08-3.14) and in multiple logistic regression (OR adjusted = 2.32, 95%CI = 1.01-5.36). In the interaction gene-environment the lack of sunscreen doubled the risk of melanoma in individuals with polymorphisms of XPD/PstI (OR adjusted = 2.17, 95%CI = 1.12-4.17). The identification of genetic polymorphisms associated with diseases such as multi factorial case of malignant melanoma should be encouraged in our country, mainly because we live in a tropical country with high solar irradiation in almost all its territory. The identification of genetic markers of susceptibility may provide early and effective prevention of cancer.

O melanoma é uma lesão maligna da pele, com alta taxa de mortalidade cuja incidência vem aumentando nos últimos anos. Os principais fatores de risco são a história familial da doença, presença de nevos benignos múltiplos ou nevos atípicos e melanoma prévio. Imunossupressão, sensibilidade ao sol e exposição intermitente e intensa à radiação UV da luz solar, sem proteção, são fatores de risco adicionais. O objetivo deste estudo caso-controle de base hospitalar foi avaliar a contribuição de polimorfismos de genes de metabolização de xenobióticos (CYP1A1/MspI, CYP2E1/PstI, GSTM1, GSTT1 e GSTP1/Bsma), de genes de reparo do DNA (XRCC1/MspI, XRCC3/NcoI e XPD/PstI) e do gene do receptor de vitamina D (VDR/FokI e VDR/TaqI) no risco de melanoma. Consentiram em participar 193 pacientes com melanoma (49,7% homens e 50,3% mulheres, média de 52 ± 14,28 anos) e 208 controles (51,4% homens e 48,6% mulheres, média de 48 ± 15,24 anos) que após responderem a um questionário detalhado sobre hábitos e tipos de exposição a fatores de risco cederam amostras biológicas para análsie do DNA por PCR-RFLP. Os principais fatores de risco para o melanoma foram ascendência européia (p<0,001), cor de olhos claros (p<0,001), presença de nevos (p<0,001), histórico de queimadura grave na adolescência (p<0,001), falta de filtro solar (p<0.034) e exposição à lâmpadas fluorescentes (p=0,001). Quanto à análise dos polimorfismos de genes de metabolização de xenobióticos somente o GSTT1 nulo revelou associação inversamente positiva com o risco de melanoma maligno (OR ajustado = 0,60; IC95% = 0,37-0,97). Entretanto, essa associação não se manteve após a análise de regressão múltipla escalonada. Os polimorfismos VDR/FokI e VDR/TaqI não modificaram a susceptibilidade ao melanoma maligno na comparação entre os grupos. Na análise conjunta do fenótipo-genótipo, indivíduos com olhos verdes e genótipo VDR/FokI polimórfico, apresentaram risco praticamente seis vezes maior de melanoma (OR ajustado = 5,93; IC95% = 1,49-23,59). A associação entre os polimorfismos em pelo menos um dos alelos dos genes de reparo do DNA, XRCC3/NcoI e XPD/PstI aumentou praticamente duas vezes o risco de melanoma tanto na análise estatística multivariada (OR ajustado = 1,84; IC95% = 1,08-3,14) quanto na regressão logística múltipla escalonada (OR ajustado = 2,32; IC95% = 1,01-5,36). Na interação genemeio ambiente a falta do uso de filtro solar dobrou o risco de melanoma em indivíduos com polimorfismo XPD/PstI (OR ajustado = 2,17; IC95% = 1,12- 4,17). A identificação de polimorfismos genéticos associados com doenças multifatorias como o caso do melanoma maligno devem ser estimuladas em nosso meio, principalmente por vivermos em um país tropical com alta incidência solar em praticamente todo seu território. A identificação de marcadores genéticos de susceptibilidade pode propiciar medidas precoces e eficazes de prevenção do câncer. / Melanoma is a malignant skin lesion, with high mortalitty rate and its incidence has been rising in the last years. The main risk factors are melanoma family history, presence of multiple benign or atypical nevi and previous melanoma. Immunosuppression, sun sensitivy and intermittent and intense exposure to UV sunlight radiation, without protection, are additional risk factors. The aim of this hospital based case-control study was to evaluate the contribution of genetic polymorphisms of xenobiotic metabolizing enzymes (CYP1A1/MspI, CYP2E1/PstI, GSTM1, GSTT1 and GSTP1/Bsma), DNA repair genes (XRCC1/MspI, XRCC3/NcoI and XPD/PstI) and vitamin D receptor genes (VDR/FokI and VDR/TaqI) to the risk of melanoma. All participants, including 193 melanoma patients (49.7% men and 50.3% women, mean age 52 ± 14.28 years old) and 208 controls (51.4% men and 48.6% women, mean age 48 ± 15.24 years old) gave written informed consent to participate in the study and agreed to donate a sample of bloody to analysis of DNA by PCR-RFLP and answer a questionarie regarding phenotypic characteristics, personal habits and questions regarding sun exposure that could be associated to the disease. The main risk factors to melanoma were European ancestries (p<0.001), light colored eyes (p<0.001), presence of nevi (p<0.001), history of sunburns during the adolescence (p<0.001), no use of sunblock (p<0.034) and exposure of fluorescent lamps (p<0.001). Regarding the genes polymorphisms, only GSTT1 null genotype showed as an inversely positivefactor (OR adjusted = 0.60; 95%CI = 0.37-0.97) to malignant melanoma. However, this association disappeared with multiple regression analysis. The VDR/FokI and VDR/TaqI polymorphisms did not alter the susceptibility to malignant melanoma in the comparison between groups. A joint analysis of phenotype-genotype, individuals with green eyes and polymorphic genotype VDR/FokI, presented almost six times more risk to melanoma (OR adjusted = 5.93, 95% CI = 1.49-23.59). The association between polymorphisms, in at least one polymorphic allele of DNA repair genes XRCC3/NcoI and XPD/PstI increased almost twice the risk of melanoma in the multivariate statistic analysis (OR adjusted = 1.84, 95%CI = 1.08-3.14) and in multiple logistic regression (OR adjusted = 2.32, 95%CI = 1.01-5.36). In the interaction gene-environment the lack of sunscreen doubled the risk of melanoma in individuals with polymorphisms of XPD/PstI (OR adjusted = 2.17, 95%CI = 1.12-4.17). The identification of genetic polymorphisms associated with diseases such as multi factorial case of malignant melanoma should be encouraged in our country, mainly because we live in a tropical country with high solar irradiation in almost all its territory. The identification of genetic markers of susceptibility may provide early and effective prevention of cancer.

Submitted by Verena Bastos (verena@uefs.br) on 2015-09-21T13:18:11Z No. of bitstreams: 1 DISSERTACAO FINAL ALINE THOMAZ.pdf: 1680438 bytes, checksum: 85bf2d7886a394df745618b6fd50d435 (MD5) / Made available in DSpace on 2015-09-21T13:18:11Z (GMT). No. of bitstreams: 1 DISSERTACAO FINAL ALINE THOMAZ.pdf: 1680438 bytes, checksum: 85bf2d7886a394df745618b6fd50d435 (MD5) Previous issue date: 2015-09-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The vitamin D receptor (VDR) is a cytoplasmic transcription factor and when activated by its ligand, translocates to the nucleus and interacts with DNA in the promoter regions with which has affinity, acting as a modulator of gene transcription and thereby producing multiple biological effects. Its main activities are the regulation and maintenance of plasma levels of calcium and phosphorus, as well as presenting immunomodulatory activities, such as the suppression of T cell activation, formation of secretion patterns of cytokines, modulation of proliferation and interference in the apoptosis. So this receptor is an important target for drugs that can help in the discovery of new immunomodulators. The present work had the objective to produce the recombinant vitamin D receptor in its soluble form for conducting future assays of drug screening of potential immunomodulators and drug-receptor interaction studies. For this, we used initially Escherichia coli expression system transformed with the plasmid HS_VDR_EC1-PQE T7, but it was only possible to obtain the protein in the insoluble fraction, even varying the temperature, time of induction and IPTG concentration. In an attempt to obtain soluble VDR, we used a eukaryotic expression system in insect cells using the baculovirus as a vector. It was built a vector, pFASTBacHT_VDR, which had the sequence of this protein cloned from pCMX.VDR. From there, it was possible to obtain recombinant bacmids used in transfection of insect cells, generating recombinant baculovirus, to then proceed with the expression of VDR. / O receptor de vitamina D (VDR) ? um fator de transcri??o g?nica citoplasm?tico e, quando ativado pelo seu ligante, transloca-se para o n?cleo e interage com regi?es promotoras no DNA com a qual apresenta afinidade, atuando como fator modulador da transcri??o g?nica e assim produzindo m?ltiplos efeitos biol?gicos. Suas principais atividades s?o a regula??o e a manuten??o dos n?veis plasm?ticos de c?lcio e f?sforo, e apresenta atividades imunomoduladoras, como a supress?o da ativa??o de c?lulas T, forma??o de padr?es de secre??o de citocinas, a modula??o da prolifera??o e interfer?ncia na apoptose. Sendo assim, esse receptor representa um importante alvo de drogas que pode contribuir na descoberta de novos f?rmacos com a??o imunomoduladora. O presente trabalho teve, como objetivo, produzir o VDR recombinante na forma sol?vel para a realiza??o de futuros ensaios de triagem de potenciais drogas com a??o imunomoduladora e estudos de intera??o droga-receptor. Para isso, foi utilizado, inicialmente, o sistema de express?o em Escherichia coli, utilizando o plasm?deo HS_VDR_EC1-PQE T7, por?m s? foi poss?vel obter a prote?na na fra??o insol?vel, mesmo variando a temperatura, o tempo de indu??o e a concentra??o de IPTG. Na tentativa de obter o VDR sol?vel, foi utilizado um sistema de express?o eucari?tico em c?lulas de inseto, utilizando como vetor o baculov?rus. Foi constru?do um vetor pFASTBacHT_VDR, o qual teve a sequ?ncia desta prote?na clonada a partir do pCMX.VDR. A partir da?, foi poss?vel obter bacm?deos recombinantes, utilizados na transfec??o de c?lulas de inseto, gerando baculov?rus recombinantes, para, ent?o, seguir com a express?o do VDR.

<p>In hyperparathyroidism (HPT) raised serum concentrations of ionized calcium is caused by increased secretion of parathyroid hormone (PTH) by parathyroid tumors. Active vitamin D, 1α,25-dihydroxyvitamin D₃, is known to suppress PTH secretion and to reduce proliferation of parathyroid tumor cells.</p><p>The aim of this thesis was to examine expression of vitamin D hydroxylating enzymes, regulating the activation and inactivation of vitamin D and to study effects of vitamin D analogues, in parathyroid tumors and breast cancer.</p><p>The vitamin D activating enzyme, CYP27B1/25-hydroxyvitamin D₃ 1α-hydroxylase (1α-hydroxylase) and the vitamin D inactivating enzyme CYP24A1/25-hydroxyvitamin D₃ 24-hydroxylase (24-hydroxylase) were expressed in parathyroid tumors and breast cancer. </p><p>The parathyroid tumors had raised expression levels of 1α-hydroxylase and reduced levels of 24-hydroxylase in comparison to normal parathyroid glands, indicating ability for endogenous activation of vitamin D. The expression of 1α-hydroxylase may be of therapeutic advantage for local activation of non-1α-hydroxylated vitamin D analogues in tumor cells, thereby reducing unwanted hypercalcemic effects. </p><p>Three of five selected low calcemic vitamin D analogues had as efficient PTH suppressing effect, in bovine parathyroid cells, as three vitamin D analogues used clinically for treatment of secondary HPT.</p><p>The non-1α-hydroxylated vitamin D analogue EB1285 showed antiproliferative and PTH suppressive effects as well as transcriptional activity in parathyroid and breast tumor cells, respectively.</p><p>Ketoconazole, an inhibitor of vitamin D hydroxylating enzymes, suppressed PTH secretion and potentiated the effect of vitamin D analogues. Combined treatment with vitamin D analogues and specific 24-hydroxylase inhibitors may be important for future therapy. </p>