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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

THE PHARMACOGENOMICS OF EGFR-DEPENDENT NSCLC: PREDICTING AND ENHANCING RESPONSE TO TARGETED EGFR THERAPY

Balko, Justin M. 01 January 2009 (has links)
The introduction of tyrosine kinase inhibitors (TKI) targeting the epidermal growth factor receptor (EGFR) inhibitors to the clinic has resulted in an improvement in the treatment of non small cell lung cancer (NSCLC). However, many patients treated with EGFR TKIs do not respond to therapy. The burden of failed treatment is largely placed on the healthcare field, limiting the effectiveness of EGFR TKIs. Furthermore, responses are hindered by the emergence of resistance. Thus, two questions must be addressed to achieve maximum benefit of EGFR inhibitors: How can patients who will benefit from EGFR TKIs be selected a priori? How can patients who respond achieve maximal benefit? To answer these questions, two hypotheses were formed. First, the EGFR-dependent phenotype, which is displayed by the tumors cells of those patients who respond clinically to EGFR TKIs, can be captured by genomic profiling of NSCLC cell lines stratified by sensitivity to EGFR TKIs. This gene signature may be used to predict the outcome of EGFR TKI therapy in unknown samples. Secondly, the predictive signature of response to EGFR TKI could provide insights into the underlying biology of the phenotype of EGFR-dependency. This information could be exploited to identify inhibitors which could be combined with EGFR inhibitors to elicit a greater effect, thereby minimizing resistance. The work herein describes the testing of these hypotheses. Pharmacogenomics was utilized to define a signature of EGFR-dependency which effectively predicted response to EGFR TKI in vitro and in vivo. Furthermore, the signature was analyzed by bioinformatic approaches to identify the RAS/MAPK pathway as a candidate target in EGFR-dependent NSCLC. The RAS/MAPK pathway regulates expression and activation of EGF-like ligands. Furthermore, the RAS/MAPK pathway modulates EGFR stability in the EGFR-dependent phenotype. Further biochemical analyses demonstrated that the RAS/MAPK pathway mediates proliferation and survival of EGFR-dependent NSCLC cells. Finally, combinatorial treatment of EGFR-dependent NSCLC cell lines with small molecules targeting EGFR and the RAS/MAPK pathway yielded cytotoxic synergy. Thus, we have used pharmacogenomics methods to potentially improve NSCLC treatment by developing a method of predicting response and identifying an additional target to combine with EGFR TKIs to maximize responses.
22

Efeitos de hipolipemiantes sobre a expressão de CYP3A4 e CYP3A5 in vitro e in vivo / Hypolipemiant effects on CYP3A4 and CYP3A5 mRNA expression in vitro and in vivo

Willrich, Maria Alice Vieira 07 October 2011 (has links)
Introdução: As CYP3A4 e CYP3A5 são enzimas do citocromo P450 responsáveis pela biotransformação de esteróides endógenos e vários fármacos, entre eles as estatinas. Polimorfismos nos genes CYP3A4 e CYP3A5 (CYP3A4*1B, CYP3A5*3C e CYP3A5*1D) foram associados com diferenças na resposta hipolipemiante de indivíduos tratados com atorvastatina e sinvastatina. Neste estudo foram avaliados os efeitos de hipolipemiantes sobre a expressão e a atividade de CYP3A4 e CYP3A5, em linhagens celulares HepG2 e Caco-2 e em CMSP de indivíduos hipercolesterolêmicos, e sua relação com variantes de CYP3A4 e CYP3A5. Métodos: Foram analisados 99 indivíduos normolipidêmicos (NL) e 139 hipercolesterolêmicos (HC). Os HC foram tratados com atorvastatina (10 mg/dia/4 semanas). A genotipagem das variantes CYP3A4*1B, CYP3A5*3C e CYP3A5*1D foi feita por PCR-RFLP ou sequenciamento. A análise da expressão de RNAm de CYP3A4 e CYP3A5 foi avaliada por PCR em tempo real quantitativo (PCRq). As proteínas totais de HepG2 foram avaliadas por Western Blotting. A atividade de CYP3A4 e CYP3A5 in vivo foi avaliada pela relação entre cortisol e seu metabólito, 6&#946;-hidróxicortisol, na urina (razão 6&#946;OH-cortisol/cortisol), por CLAE. Resultados: O perfil de expressão basal de RNAm de CYP3A4 e CYP3A5 é diferente entre HepG2 e Caco-2. Caco-2 expressa 31 vezes mais CYP3A4 e 122 vezes mais CYP3A5 que HepG2. Em células HepG2 tratadas por 12 h, a atorvastatina 20 &#181;M aumentou a expressão de CYP3A4 em 10 vezes, em relação ao controle (p=0,006). Após 24 h de tratamento, atorvastatina (1-20 &#181;M) aumentou a expressão de CYP3A4 em 5 a 8 vezes, nas HepG2 (p< 0,001). Para CYP3A5, a exposição por 12 h à atorvastatina 20 &#181;M aumentou a expressão em 4 vezes em relação ao controle ( p<0,001). A exposição à sinvastatina 1,0 &#181;M por 24 h aumentou a expressão de CYP3A4, em 2 vezes (p<0,01), em HepG2. Também se observou que, nesse tempo de tratamento, a sinvastatina (0,1 &#181;M a 10 &#181;M) aumentou a expressão de CYP3A5 em 2 a 4 vezes (p<0,05). A linhagem HepG2 apresenta alelos funcionais (CYP3A4*1A e CYP3A5*1A) em homozigose. A linhagem Caco-2 apresenta os alelos não funcionais CYP3A5*3C e CYP3A5*1D, em heterozigose. Também foi avaliada a expressão das proteínas CYP3A4 e CYP3A5 por Western Blotting, em células HepG2, após atorvastatina (0,1 a 20 &#181;M) e sinvastatina (0,01 a 10 &#181;M) por 12 e 24 h. O perfil de expressão das proteínas não diferiu com os tratamentos. Nas células mononucleares do sangue periférico (CMSP), a expressão de RNAm basal de CYP3A4 é cerca de 2,5 a 9,6 vezes maior que a expressão de CYP3A5 (p< 0,05). Observou-se correlação da expressão de CYP3A4 e CYP3A5 nessas células, antes (r2 = 0,22; p< 0,0001) e após o tratamento (r2 = 0,58; p<0,0001) com atorvastatina. A expressão basal de RNAm de CYP3A4 e CYP3A5 é maior nos indivíduos (NL) que nos indivíduos (HC) (p<0,05). A atorvastatina não influenciou a expressão de CYP3A4 e CYP3A5 em CMSP (p> 0,05). Os indivíduos NL apresentam atividade de CYP3A4 e CYP3A5 basal maior que os indivíduos HC- (p<0,0001). O tratamento com atorvastatina não alterou a atividade de CYP3A4 e CYP3A5 nos HC (p>0,05). As variantes gênicas estudadas (CYP3A4*1B, CYP3A5*3C e CYP3A5*1D) como grupos haplotípicos não afetaram a resposta ao tratamento, a expressão de RNAm ou a atividade de CYP3A4 e CYP3A5, embora o haplótipo AGT tenha expressão basal de RNAm de CYP3A5 menor que os portadores de haplótipos GAT e GAC (p<0,005). Conclusão: Os resultados deste trabalho nos permitem concluir que a atorvastatina e a sinvastatina, mas não a ezetimiba, influenciam a expressão de CYP3A4 e CYP3A5 in vitro, em linhagem derivada de hepatócitos (HepG2), e que este efeito não foi reproduzido em linhagem derivada de enterócitos (Caco-2). A expressão de CYP3A4 e CYP3A5 tem grande variabilidade interindividual, independente do grupo haplotípico de cada indivíduo, e que não é influenciada pela atorvastatina. / Background: CYP3A4 and CYP3A5 are enzymes from the cytochrome P450 resposible for the biotransformation of endogenous steroids and several drugs, e.g. statins. Polymorphisms in CYP3A4 and CYP3A5 (CYP3A4*1B, CYP3A5*3C and CYP3A5*1D) have been associated with variation of lipid-lowering response in individuals treated with atorvastatin and simvastatin. In this study we evaluated the effect of hypolipemiants on expression and activity of CYP3A4 and CYP3A5, in HepG2 and Caco-2 cell lines as well as peripheral blood mononuclear cells (PBMC) in hypercholesterolemic individuals, and their relationship with CYP3A4 and CYP3A5 variants. Methods: We analyzed 99 normolipidemic individuals (NL) and 139 hypercholesterolemic (HC). HC subjects were treated with atorvastatin (HC, 10 mg/day/4 weeks). Analysis of CYP3A4*1B, CYP3A5*3C e CYP3A5*1D variants was performed with PCR-RFLP or sequencing assays and mRNA expression of CYP3A4 and CYP3A5 with Quantitative Real-time PCR (qRT-PCR) was performed . Total protein content was extracted from HepG2 for Western Blotting experiments. Activity of CYP3A4 and CYP3A5 in vivo was evaluated by 6&#946;OH-cortisol and cortisol ratio in urine samples, by HPLC-UV method. Results: Baseline mRNA expression is different for HepG2 and Caco-2. Caco-2 expresses 31 times more CYP3A4 and 122 times more CYP3A5 than HepG2. In HepG2 cells treated for 12h, atorvastatin 20 &#181;M increased CYP3A4 expression in 10 times, when compared to the control (p=0.006). After 24h treatment, atorvastatin (1-20 &#181;M) increased CYP3A4 mRNA expression in 5 to 8 times, in HepG2 (p< 0.001). To CYP3A5, exposure for 12h to atorvastatin 20 &#181;M increased expression in 4 times when compared to the control (p<0.001). Exposure to simvastatin 1.0 &#181;M for 24 h increased CYP3A4 expression in 2 times, (p<0.01), in HepG2. With the 24h treatment,simvastatin (0.1 &#181;M - 10 &#181;M) CYP3A5 showed increased mRNA expression in 2 to 4 times (p<0.05). HepG2 cell line carries homozygous functional alleles (CYP3A4*1A e CYP3A5*1A). Caco-2 carries heterozygous CYP3A5*3C and CYP3A5*1D. We evaluated the protein expression of CYP3A4 and CYP3A5 with Western Blotting in HepG2 cells, after atorvastatin (0.1 - 20 &#181;M) and simvastatin (0.01 - 10 &#181;M) for 12 and 24 h. The proteins profile did not change with statins treatment. In PBMC, baseline mRNA expression of CYP3A4 is approximately 2.6 to 9.5 times higher than CYP3A5 (p< 0.05). There was a correlation in expression between CYP3A4 and CYP3A5, before (r2 = 0.22; p< 0.0001) and after treatment (r2 = 0.58; p<0.0001) with atorvastatin. Baseline mRNA expression of CYP3A4 and CYP3A5 is higher in (NL) than in (HC) (p<0.05). Atorvastatin treatment did not increase CYP3A4 and CYP3A5 mRNA in PBMC (p>0.05). CYP3A4/5 activity was higher in NL subjects than in HC (p<0.0001). Atorvastatin treatment did not affect CYP3A4/5 activity in HC (p>0.05). The studied variants CYP3A4*1B, CYP3A5*3C e CYP3A5*1D analyzed as a haplotype block did not affect response to treatment, mRNA expression or activity of CYP3A4 and CYP3A5. However, AGT haplotype showed lower CYP3A5 mRNA expression levels when compared to GAC and GAT haplotypes at baseline (p<0.05). Conclusion: The results of this study allow us to conclude that atorvastatin and simvastatin, but not ezetimibe, influence the expression of CYP3A4 and CYP3A5 mRNA in vitro in HepG2 cell line, but this effect was not reproduced in Caco-2 cell line or PBMC. CYP3A4 and CYP3A5 present great interindividual variability, despite the individual´s haplotype and is not influenced by atorvastatin.
23

Individualized Cancer Treatment based on Pharmacogenomics Analysis

Khalaf, Rossa, Bossaer, John B., Spradling, Elnora N. 01 April 2017 (has links)
5-Fluorouracil (5-FU) is one of most frequently used chemotherapeutic medications for the treatment of many types of cancer in curative and palliative setting. It is important to recognize chemotherapy side effects and toxicities because some of these symptoms may indicate a clinical syndrome needing evaluation for a principal cause. We discuss a patient who developed severe mucositis requiring hospitalization after first use of Fluorouracil. Dihydropyrimidine dehydrogenase ( DPD) deficiency was suspected and was proven to be a cause of severe drug-related toxicity. Our patient is fifty six year old gentleman with stage III nasopharyngeal squamous cell carcinoma who developed two masses on right side of the neck and large posterior right nasopharyngeal mass. Patient was treated with concurrent chemotherapy with high dose of cisplatin along with radiation. Once completion of concurrent chemotherapy and radiation he was started on combination of 5-Fluorouracil and cisplatin. Three days after completion of ninety six hour continuous 5-flurouracil infusion patient developed severe mucositis. Clinical exam was consistent with swollen tongue and mouth and inability to clear oral secretions. Patient was tested for DPYD gene mutation. Testing showed heterozygous for the c.1679T>G(*13) variant in the DPYD gene consistent with predicted intermediate DPD activity (30-70% enzyme activity). About 80% of administered 5-fluorouracil is normally inactivated by DPD. A decrease in DPD enzymatic activity may lead to increased concentrations of 5-FU and elevated risk for severe toxicities. Standard dose of 5-FU was decreased by 50% with second cycle of chemotherapy. Patient tolerated the second cycle of chemotherapy well. Variants in the DPD gene can lead to reduced 5-FU catabolism resulting in severe toxicities. Some of the toxicities can cause death. It is important to screen for this deficiency and closely observe patients during chemotherapy treatment.
24

Genetic Determinants of the Acute Effects and Withdrawal Symptoms of Caffeine

Day-Tasevski, Erica 06 April 2010 (has links)
The mechanisms underlying caffeine’s acute effects and withdrawal symptoms are not entirely understood. The purpose was to determine whether these effects or symptoms co-exist in clusters, and whether they are associated with polymorphisms in β1- and β2-adrenoceptors. Subjects (n=1271) were from the Toronto Nutrigenomics and Health Study. The acute effects and withdrawal symptoms clustered into 4 and 6 factors, respectively. Subjects with the ADRβ2 Gly16Arg Gly/Arg genotype were more likely than Gly allele homozygotes to report “fatigue” withdrawal symptoms. Among >200 mg/d caffeine consumers, ADRβ2 Gly allele carriers had a greater risk, compared to Arg allele homozygotes, of reporting ‘flu-like somatic’ withdrawal symptoms. Among subjects with the CYP1A2 -163 A>C A/A genotype and 100-200 mg/d caffeine consumers, ADRβ1 Arg389Gly Gly allele carriers had a greater risk, compared to Arg allele homozygotes, of reporting “dysphoric mood” withdrawal symptoms. The findings suggest that β1- and β2- adrenoceptors play a role in caffeine withdrawal.
25

Genetic Determinants of the Acute Effects and Withdrawal Symptoms of Caffeine

Day-Tasevski, Erica 06 April 2010 (has links)
The mechanisms underlying caffeine’s acute effects and withdrawal symptoms are not entirely understood. The purpose was to determine whether these effects or symptoms co-exist in clusters, and whether they are associated with polymorphisms in β1- and β2-adrenoceptors. Subjects (n=1271) were from the Toronto Nutrigenomics and Health Study. The acute effects and withdrawal symptoms clustered into 4 and 6 factors, respectively. Subjects with the ADRβ2 Gly16Arg Gly/Arg genotype were more likely than Gly allele homozygotes to report “fatigue” withdrawal symptoms. Among >200 mg/d caffeine consumers, ADRβ2 Gly allele carriers had a greater risk, compared to Arg allele homozygotes, of reporting ‘flu-like somatic’ withdrawal symptoms. Among subjects with the CYP1A2 -163 A>C A/A genotype and 100-200 mg/d caffeine consumers, ADRβ1 Arg389Gly Gly allele carriers had a greater risk, compared to Arg allele homozygotes, of reporting “dysphoric mood” withdrawal symptoms. The findings suggest that β1- and β2- adrenoceptors play a role in caffeine withdrawal.
26

A pharmacokinetic study of rifabutin and its interaction with antiretrovirals in African patients with TB-HIV co-infection.

Naiker, Suhashni. 23 October 2013 (has links)
The management of HIV-associated tuberculosis (TB) is complicated by the pharmacokinetic interactions between rifampicin (RMP) and co-administered protease inhibitors (PIs) and non-nucleoside reverse transcriptase inhibitors. Rifabutin (RBT) is an alternative rifamycin, preferred in patients requiring PIs. Recent studies suggest the current recommended dose of RBT in combination with boosted lopinavir (LPV/r) is suboptimal and there are insufficient pharmacokinetic data evaluating the interaction between RBT coadministered with efavirenz (EFV) and nevirapine (NVP). Pharmacogenomic studies have shown that RMP concentrations are lower in patients from sub-Saharan Africa with polymorphisms of the SLCO1B1gene but there is currently no data on the pharmacogenetic determinants of RBT exposure. The pharmacokinetics of RBT were evaluated at two different doses in HIV co-infected patients before and after the introduction of LPV/r, EFV and NVPbased antiretroviral therapy (ART). After six weeks of standard TB therapy, RBT 300 mg daily was started for four weeks. Thereafter patients were randomized to receive either RBT 150 mg daily or RBT 150 mg three times a week (TPW) with LPV/r, RBT 300mg or 450mg with NVP or RBT- 450mg or 600mg with efavirenz. After four weeks on the first RBT dose, patients switched to the alternate dose and continued until the end of TB treatment. Serial RBT and 25-O-desacetylrifabutin (dRBT) concentrations were measured during a dose interval before patients switched RBT doses. The median AUC0-24 and Cmax, of RBT in patients taking 150mg RBT TPW was significantly reduced when compared to the other treatment arms. 86% of patients whilst on this intermittent RBT arm had an AUC0-24 < 4.5 μg.h/mL, level that has been associated with acquired rifamycin resistance. Rifabutin exposure was maintained within the range of AUCs that have been shown to prevent acquired rifamycin resistance (ARR) with 150mg daily dosing in combination with LPV/r. In addition, the combination of RBT with NVP 300mg resulted in significantly increased exposure of RBT, with significantly higher exposure observed with 600mg RBT. However, the combination of RBT 450mg with EFV resulted in RBT exposure lower than 300mg RBT given alone in the same patients, whereas RBT 600mg plus NVP results in bioavailability of RBT equivalent to 300mg given alone. Rifabutin was well tolerated at all doses. Only three grade 4 laboratory toxicities, elevated transaminases, neutropenia, and uveitis, possibly related to RBT were reported in patients taking NVP. SLCO1B1 rs4149032 C>T polymorphism occurs frequently in African patients in Durban and may be associated with low RBT bioavailability. These findings support recommendations for the higher dose of RBT in combination with LPV and EFV but not with NVP. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2012.
27

Genetic association analysis of polymorphisms in four cytochrome P450 genes, the MDR1 gene and treatment-outcome in Xhosa schizophrenia patients /

Truter, Erika. January 2007 (has links)
Thesis (MSc)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.
28

Efeitos de hipolipemiantes sobre a expressão de CYP3A4 e CYP3A5 in vitro e in vivo / Hypolipemiant effects on CYP3A4 and CYP3A5 mRNA expression in vitro and in vivo

Maria Alice Vieira Willrich 07 October 2011 (has links)
Introdução: As CYP3A4 e CYP3A5 são enzimas do citocromo P450 responsáveis pela biotransformação de esteróides endógenos e vários fármacos, entre eles as estatinas. Polimorfismos nos genes CYP3A4 e CYP3A5 (CYP3A4*1B, CYP3A5*3C e CYP3A5*1D) foram associados com diferenças na resposta hipolipemiante de indivíduos tratados com atorvastatina e sinvastatina. Neste estudo foram avaliados os efeitos de hipolipemiantes sobre a expressão e a atividade de CYP3A4 e CYP3A5, em linhagens celulares HepG2 e Caco-2 e em CMSP de indivíduos hipercolesterolêmicos, e sua relação com variantes de CYP3A4 e CYP3A5. Métodos: Foram analisados 99 indivíduos normolipidêmicos (NL) e 139 hipercolesterolêmicos (HC). Os HC foram tratados com atorvastatina (10 mg/dia/4 semanas). A genotipagem das variantes CYP3A4*1B, CYP3A5*3C e CYP3A5*1D foi feita por PCR-RFLP ou sequenciamento. A análise da expressão de RNAm de CYP3A4 e CYP3A5 foi avaliada por PCR em tempo real quantitativo (PCRq). As proteínas totais de HepG2 foram avaliadas por Western Blotting. A atividade de CYP3A4 e CYP3A5 in vivo foi avaliada pela relação entre cortisol e seu metabólito, 6&#946;-hidróxicortisol, na urina (razão 6&#946;OH-cortisol/cortisol), por CLAE. Resultados: O perfil de expressão basal de RNAm de CYP3A4 e CYP3A5 é diferente entre HepG2 e Caco-2. Caco-2 expressa 31 vezes mais CYP3A4 e 122 vezes mais CYP3A5 que HepG2. Em células HepG2 tratadas por 12 h, a atorvastatina 20 &#181;M aumentou a expressão de CYP3A4 em 10 vezes, em relação ao controle (p=0,006). Após 24 h de tratamento, atorvastatina (1-20 &#181;M) aumentou a expressão de CYP3A4 em 5 a 8 vezes, nas HepG2 (p< 0,001). Para CYP3A5, a exposição por 12 h à atorvastatina 20 &#181;M aumentou a expressão em 4 vezes em relação ao controle ( p<0,001). A exposição à sinvastatina 1,0 &#181;M por 24 h aumentou a expressão de CYP3A4, em 2 vezes (p<0,01), em HepG2. Também se observou que, nesse tempo de tratamento, a sinvastatina (0,1 &#181;M a 10 &#181;M) aumentou a expressão de CYP3A5 em 2 a 4 vezes (p<0,05). A linhagem HepG2 apresenta alelos funcionais (CYP3A4*1A e CYP3A5*1A) em homozigose. A linhagem Caco-2 apresenta os alelos não funcionais CYP3A5*3C e CYP3A5*1D, em heterozigose. Também foi avaliada a expressão das proteínas CYP3A4 e CYP3A5 por Western Blotting, em células HepG2, após atorvastatina (0,1 a 20 &#181;M) e sinvastatina (0,01 a 10 &#181;M) por 12 e 24 h. O perfil de expressão das proteínas não diferiu com os tratamentos. Nas células mononucleares do sangue periférico (CMSP), a expressão de RNAm basal de CYP3A4 é cerca de 2,5 a 9,6 vezes maior que a expressão de CYP3A5 (p< 0,05). Observou-se correlação da expressão de CYP3A4 e CYP3A5 nessas células, antes (r2 = 0,22; p< 0,0001) e após o tratamento (r2 = 0,58; p<0,0001) com atorvastatina. A expressão basal de RNAm de CYP3A4 e CYP3A5 é maior nos indivíduos (NL) que nos indivíduos (HC) (p<0,05). A atorvastatina não influenciou a expressão de CYP3A4 e CYP3A5 em CMSP (p> 0,05). Os indivíduos NL apresentam atividade de CYP3A4 e CYP3A5 basal maior que os indivíduos HC- (p<0,0001). O tratamento com atorvastatina não alterou a atividade de CYP3A4 e CYP3A5 nos HC (p>0,05). As variantes gênicas estudadas (CYP3A4*1B, CYP3A5*3C e CYP3A5*1D) como grupos haplotípicos não afetaram a resposta ao tratamento, a expressão de RNAm ou a atividade de CYP3A4 e CYP3A5, embora o haplótipo AGT tenha expressão basal de RNAm de CYP3A5 menor que os portadores de haplótipos GAT e GAC (p<0,005). Conclusão: Os resultados deste trabalho nos permitem concluir que a atorvastatina e a sinvastatina, mas não a ezetimiba, influenciam a expressão de CYP3A4 e CYP3A5 in vitro, em linhagem derivada de hepatócitos (HepG2), e que este efeito não foi reproduzido em linhagem derivada de enterócitos (Caco-2). A expressão de CYP3A4 e CYP3A5 tem grande variabilidade interindividual, independente do grupo haplotípico de cada indivíduo, e que não é influenciada pela atorvastatina. / Background: CYP3A4 and CYP3A5 are enzymes from the cytochrome P450 resposible for the biotransformation of endogenous steroids and several drugs, e.g. statins. Polymorphisms in CYP3A4 and CYP3A5 (CYP3A4*1B, CYP3A5*3C and CYP3A5*1D) have been associated with variation of lipid-lowering response in individuals treated with atorvastatin and simvastatin. In this study we evaluated the effect of hypolipemiants on expression and activity of CYP3A4 and CYP3A5, in HepG2 and Caco-2 cell lines as well as peripheral blood mononuclear cells (PBMC) in hypercholesterolemic individuals, and their relationship with CYP3A4 and CYP3A5 variants. Methods: We analyzed 99 normolipidemic individuals (NL) and 139 hypercholesterolemic (HC). HC subjects were treated with atorvastatin (HC, 10 mg/day/4 weeks). Analysis of CYP3A4*1B, CYP3A5*3C e CYP3A5*1D variants was performed with PCR-RFLP or sequencing assays and mRNA expression of CYP3A4 and CYP3A5 with Quantitative Real-time PCR (qRT-PCR) was performed . Total protein content was extracted from HepG2 for Western Blotting experiments. Activity of CYP3A4 and CYP3A5 in vivo was evaluated by 6&#946;OH-cortisol and cortisol ratio in urine samples, by HPLC-UV method. Results: Baseline mRNA expression is different for HepG2 and Caco-2. Caco-2 expresses 31 times more CYP3A4 and 122 times more CYP3A5 than HepG2. In HepG2 cells treated for 12h, atorvastatin 20 &#181;M increased CYP3A4 expression in 10 times, when compared to the control (p=0.006). After 24h treatment, atorvastatin (1-20 &#181;M) increased CYP3A4 mRNA expression in 5 to 8 times, in HepG2 (p< 0.001). To CYP3A5, exposure for 12h to atorvastatin 20 &#181;M increased expression in 4 times when compared to the control (p<0.001). Exposure to simvastatin 1.0 &#181;M for 24 h increased CYP3A4 expression in 2 times, (p<0.01), in HepG2. With the 24h treatment,simvastatin (0.1 &#181;M - 10 &#181;M) CYP3A5 showed increased mRNA expression in 2 to 4 times (p<0.05). HepG2 cell line carries homozygous functional alleles (CYP3A4*1A e CYP3A5*1A). Caco-2 carries heterozygous CYP3A5*3C and CYP3A5*1D. We evaluated the protein expression of CYP3A4 and CYP3A5 with Western Blotting in HepG2 cells, after atorvastatin (0.1 - 20 &#181;M) and simvastatin (0.01 - 10 &#181;M) for 12 and 24 h. The proteins profile did not change with statins treatment. In PBMC, baseline mRNA expression of CYP3A4 is approximately 2.6 to 9.5 times higher than CYP3A5 (p< 0.05). There was a correlation in expression between CYP3A4 and CYP3A5, before (r2 = 0.22; p< 0.0001) and after treatment (r2 = 0.58; p<0.0001) with atorvastatin. Baseline mRNA expression of CYP3A4 and CYP3A5 is higher in (NL) than in (HC) (p<0.05). Atorvastatin treatment did not increase CYP3A4 and CYP3A5 mRNA in PBMC (p>0.05). CYP3A4/5 activity was higher in NL subjects than in HC (p<0.0001). Atorvastatin treatment did not affect CYP3A4/5 activity in HC (p>0.05). The studied variants CYP3A4*1B, CYP3A5*3C e CYP3A5*1D analyzed as a haplotype block did not affect response to treatment, mRNA expression or activity of CYP3A4 and CYP3A5. However, AGT haplotype showed lower CYP3A5 mRNA expression levels when compared to GAC and GAT haplotypes at baseline (p<0.05). Conclusion: The results of this study allow us to conclude that atorvastatin and simvastatin, but not ezetimibe, influence the expression of CYP3A4 and CYP3A5 mRNA in vitro in HepG2 cell line, but this effect was not reproduced in Caco-2 cell line or PBMC. CYP3A4 and CYP3A5 present great interindividual variability, despite the individual´s haplotype and is not influenced by atorvastatin.
29

Coriandrum sativum L. (coriander) essential oil = antifungal activity and mode of action on Candida spp., and molecular targets affected in the human whole whole-genome expression = Atividade antifúngica e modo de ação do óleo essencial de Coriandrum sativum L. (coentro) sobre Candida spp. e alvos moleculares afetados na expressão do genoma humano / Atividade antifúngica e modo de ação do óleo essencial de Coriandrum sativum L. (coentro) sobre Candida spp. e alvos moleculares afetados na expressão do genoma humano

Freires, Irlan de Almeida, 1988- 24 August 2018 (has links)
Orientadores: Pedro Luiz Rosalen, Marta Cristina Teixeira Duarte / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-24T14:33:59Z (GMT). No. of bitstreams: 1 Freires_IrlandeAlmeida_M.pdf: 5300507 bytes, checksum: c7e268d2d061cfb090db127a48e976f8 (MD5) Previous issue date: 2014 / Resumo: Introdução: A candidíase oral é uma infecção fúngica oportunista da cavidade oral, cujas taxas de prevalência e incidência vêm aumentando significativamente em todo o mundo. Assim, novas estratégias orientadas para gerir esta doença têm sido propostas, dentre as quais está o uso de óleos essenciais (OE) com propriedades antifúngicas. Evidências indicam que o OE de Coriandrum sativum L. (coentro) é um forte agente antifúngico contra Candida e, portanto, investigações devem dar continuidade ao conhecimento gerado. Objetivo: Este estudo buscou avaliar a atividade antifúngica e modo de ação do OE de C. sativum sobre Candida spp., e determinar os alvos moleculares afetados na expressão global do genoma humano. Material e Métodos: C. sativum foi obtido a partir do Banco de Germoplasmas do Centro Pluridisciplinar de Pesquisas Químicas, Biológicas e Agrícolas (Universidade Estadual de Campinas, SP, Brasil) cujo OE e fração ativa tiveram o perfil fitoquímico determinado por cromatografia gasosa acoplada a espectrometria de massa. Posteriormente, foram realizados testes com cinco cepas de referência de Candida: Determinação da Concentração Inibitória e Fungicida Mínima (CIM/CFM); modo de ação antifúngica (ensaio do sorbitol e ergosterol); Microscopia Eletrônica de Varredura (MEV) de biofilmes de Candida e testes de inibição de aderência em biofilme. Utilizou-se nistatina, anfotericina B ou caspofungina como controles positivos, além de controles negativos. Também, foi testado o efeito do OE sobre a atividade proteolítica de C. albicans. Por fim, um ensaio de farmacogenômica identificou quais alvos moleculares no genoma humano foram afetados pelo OE e fração ativa de C. sativum. Os testes foram realizados em triplicata de experimentos independentes e os dados foram tratados estatisticamente (ANOVA, pós-teste de Tukey, ?=0,05). Os dados da análise farmacogenômica foram processados nas plataformas GeneGo MetaCore® e David Bioinformatics Resources. Resultados: O perfil fitoquímico EO indicou monoterpenos (37,9%) e sesquiterpenos (62,1%) como compostos principais. Os valores de CIM/CFM para o OE variaram de 15,6 a 62,5 µg/mL. Quanto ao modo de ação, o OE de C. sativum parece se ligar ao ergosterol da membrana celular fúngica, aumentando a permeabilidade iônica e causando morte celular; entretanto, o OE não atua sobre vias de biossíntese da parede celular. Estes achados confirmam as alterações na integridade da morfologia do biofilme verificadas nas análises por MEV. Além disso, o OE apresentou atividade antiaderente em biofilme em baixas concentrações (15,6-62,5 µg/mL) contra as cepas testadas, bem como atividade contra proteases produzidas por C. albicans, sendo estatisticamente significante na CIM (p<0,05). Finalmente, o OE e sua fração ativa apresentaram baixa citotoxicidade em células humanas com CI30 de 359,8 e 366,7 µg/mL, respectivamente. As principais vias afetadas estão relacionadas com quimiocinas e MAP-quinase (apoptose, proliferação) bem como proteínas de adesão. Conclusões: O OE das folhas de C. sativum tem forte atividade antifúngica e antiaderente sobre Candida spp. e atividade anti-proteolítica sobre C. albicans, e atua aumentando a permeabilidade iônica da membrana celular, provavelmente devido ao efeito sinérgico de mono e sesquiterpenos. Análise farmacogenômica indicou baixa citotoxicidade do OE e sua fração ativa com alvos moleculares específicos afetados no genoma humano, o que incentiva o desenvolvimento de novas pesquisas pré-clínicas toxicológicas e clínicas nesta área / Abstract: Introduction: Oral candidiasis is a common opportunistic fungal infection of the oral cavity with increasingly significant worldwide prevalence and incidence rates. Accordingly, novel specific-targeted strategies to manage this ailment have been proposed, among which is the use of essential oils (EO) with antifungal properties. Coriandrum sativum L. (coriander) EO has proven antifungal activity against Candida species and thus deserves further investigation. Objective: This study aimed to evaluate the antifungal activity and mode of action of the EO from Coriandrum sativum L. leaves on Candida spp., and to determine the molecular targets affected in the whole-genome expression in human cells. Material and Methods: C. sativum was obtained from the Germoplasm Bank of the Research Center for Chemistry, Biology and Agriculture (University of Campinas, SP, Brazil) whose EO and active fraction had their phytochemical profile determined by Gas Chromatography coupled to Mass Spectrometry. Then, we carried out the following tests with five reference strains of Candida spp. (CBS): Minimum Inhibitory and Fungicidal Concentration (MIC/MFC); antifungal mode of action (sorbitol and ergosterol assays); Scanning Electron Microscopy (SEM) analysis of Candida biofilm and tests of inhibition of biofilm adherence. We used nystatin, amphotericin B or caspofungin as positive controls, in addition to negative controls. Also, we tested the effect of C. sativum EO on the proteolytic activity of C. albicans. Next, a pharmacogenomic assay identified which molecular targets in the human genome were affected by C. sativum EO and its active fraction. Tests were performed in triplicate of independent experiments and data were statistically treated (ANOVA, Tukey¿s post-test, ?=0.05). Pharmacogenomic data were processed on GeneGo MetaCore® and DAVID Bioinformatics Resources. Results: The EO phytochemical profile indicated monoterpenes (37.9 %) and sesquiterpenes (62.1 %) as major compounds. The MIC/MFC values for the EO ranged from 15.6 to 62.5 µg/ml. With regard to the mode of action, C. sativum EO may bind to membrane ergosterol, increasing ionic permeability and causing membrane damage to cell death, but it does not act on cell wall biosynthesis-related pathways. This mode of action confirms the changes in the integrity of the biofilm morphology as verified in the analyses by SEM. The EO showed anti-adherent activity at low concentrations (31.2 ¿ 62.5 µg/ml) against all strains tested, as well as activity against proteases produced by C. albicans, with statistical significance at MIC (P < 0.05). Finally, the EO and its active fraction had low cytotoxicity on human cells with IC30 of 359.8 and 366.7 µg/ml, respectively, affecting the pathways of chemokines and MAP-kinase (apoptosis, proliferation), as well as adhesion proteins. Conclusions: The EO from C. sativum leaves has strong antifungal and anti-adherent activity against Candida spp., as well as anti-proteolytic activity against C. albicans, and acts by increasing cell membrane ionic permeability, probably due to the synergistic effect of mono- and sesquiterpenes. Pharmacogenomic analyses revealed low cytotoxicity with specific targets affected in the human genome, which encourages further pre-clinical toxicological screening and clinical research in this field / Mestrado / Farmacologia, Anestesiologia e Terapeutica / Mestre em Odontologia
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Optimization of pyrosequencing method for copy number analysis of CYP2D6

Carls, Stefan January 2017 (has links)
CYP2D6, a member of the cytochrome P450 enzyme system, has a central role in drug metabolism, it metabolizes 25 % of clinically used drugs. The gene that codes for the enzyme displays a high degree of polymorphism, which effects enzyme functions to various degrees. Aside from smaller mutations like SNPs, alleles may also feature duplications or deletion of the whole gene. Due to the clinical relevance of these mutations, a simple and precise method for genotyping is needed. In this study, a method based on pyrosequencing for copy number analysis was evaluated, wherein the copy number was determined by relative quantification to a reference gene CYP2D8P. During evaluation of the method, several adjustments were tried for optimization, including adjustments of annealing temperature and primer concentration. The results showed a difficulty in distinguishing between copy numbers using the method, as well as a high coefficient of variation. Therefore, further optimization is required before the method could be implemented into clinical practice.

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