Magíster en farmacología / El carcinoma escamoso de laringe es una enfermedad altamente invalidante ya que puede afectar la capacidad del habla, respiración y deglución del paciente que lo sufre. Los principales factores causales identificados son cigarro y alcohol. Las vías de respuesta inflamatoria, proliferativa y de reparación de ADN pueden contribuir al riesgo de cáncer de laringe. El objetivo de este estudio es determinar asociaciones entre variantes genéticas COX-2 rs20417, COX-2 rs689466, EGF rs4444903, EGFR rs2227983, P53 rs1042522 y el riesgo de cáncer de laringe en la población chilena. Se realizó un estudio casos y controles, con 100 pacientes con cáncer escamoso de laringe y 139 voluntarios adultos sin cáncer. La genotipificación se realizó mediante PCR-RLFP. Se observa que estos polimorfismos son capaces de incrementar el riesgo de cáncer de laringe asociado a la combinación de consumo de tabaco y alcohol en una razón de 0,34 veces para COX-2 rs20417, 0,5 veces para EGF rs4444903, 0,56 veces para P53 rs1042522, 1,72 veces para EGFR rs2227983 y 4,7 veces para COX-2 rs689466. Esto sugiere que las variantes COX-2 rs20417, COX-2 rs689466, EGF rs4444903, EGFR rs2227983 y P53 rs1042522 actúan como modificadores de riesgo de cáncer de laringe. / Laryngeal squamous cell carcinoma is a kind of cancer that can be highly disabling to the patient, affecting speech, swallowing and respiratory skills, and leading to impaired quality of life. Smoking and alcohol abuse are principal risk factors linked to this disease. Inflammation signaling pathways, mitogens and DNA repair genes are factors that can be involved in carcinogenesis. The aim of this research is to assess the effect of COX-2 rs20417, COX-2 rs689466, EGF rs4444903, EGFR rs2227983, P53 rs1042522 single nucleotide polymorphisms in the risk of laryngeal cancer development in Chilean population. For this case control study, we recruited 100 cancer patients and 139 healthy volunteers. SNP genotype was analyzed from genomic DNA by PCR-RFLP. We observed that these SNPs are capable of increase the smoking plus alcohol risk of laryngeal cancer in a ratio of 0,34 fold for COX-2 rs20417 SNP, 0,5 fold for EGF rs4444903 SNP, 0,56 fold for P53 rs1042522 SNP, 1,72 fold for EGFR rs2227983 SNP and 4,7 fold for COX-2 rs689466 SNP. These findings suggest that COX-2 rs20417, COX-2 rs689466, EGF rs4444903, EGFR rs2227983 and P53 rs1042522 single nucleotide polymorphisms acts as risk modifier factors for laryngeal cancer.

GRado de magíster en ciencias biológicas, mención biología celular y molecular. / A nivel mundial, el cáncer de mama (CM), es el más frecuente y la principal causa de muerte por cáncer en mujeres (14%), representando el 23% del total de casos nuevos de cáncer. En Chile, es la primera causa de muerte por cáncer en mujeres, y la mortalidad por CM, ha ido en aumento en las últimas dos décadas. Debido a lo anterior, es pertinente realizar estudios que permitan conocer mejor sus bases etiológicas, para poder tomar medidas que permitan su prevención y su detección temprana. En la literatura existen variadas publicaciones en relación a genes codificantes que aumentan la susceptibilidad a desarrollar CM. Este, es el caso de los genes BRCA1/2, ATM, PALB2 entre otros, sin embargo en los últimos años se ha puesto mayor atención a la influencia que pudiesen tener secuencias no codificantes sobre el riesgo de desarrollar CM. Especialmente, existe gran interés en los miRNAs, y polimorfismos presentes en ellos, que pudieran ser la causa de aumento de riesgo para CM. Se ha demostrado que la presencia de SNPs en las secuencias de precursores o miRNAs maduros, afecta la maduración y el procesamiento de estos RNAs pequeños, así como también el silenciamiento de sus mRNAs blancos, proponiéndose este mecanismo como el responsable del desarrollo de diversas patologías entre ellas el CM. En este trabajo se analizaron las frecuencias alélicas y genotípicas de tres SNPs (rs2910164, rs3764444 y rs11614913) presentes en los miRNAs 146a y miRNA-499 y miRNA-196 respectivamente, y su asociación con el aumento de susceptibilidad a desarrollar CM en mujeres chilenas. Los resultados muestran que los SNPs presentes tanto en el miRNA-499 como en el miRNA-196, disminuyen el riesgo a desarrollar CM y actuarían como potenciales factores protectores para la patología. Por el contrario, el SNP presente en el miRNA-146a se asoció con aumento de riesgo para desarrollar CM en mujeres con CM esporádico, sin historia familiar para la patología, mientras que en pacientes con historia familiar mostró ser un factor protector. Estos resultados muestran la complejidad biológica que estaría detrás de cada tipo de CM, y los efectos tan distintos que los miRNAs podrían tener en diferentes contextos celulares. Para estudiar la funcionalidad biológica que pudiese tener el SNP presente en el pre- miRNA- 146a, se clonó este fragmento desde pacientes portadores para el alelo de riesgo y de sujetos controles, para posteriormente estudiar su efecto in vitro mediante la transfección en células de mama humana. Aunque no analizado, se espera que un cambio en la secuencia de un precursor de miRNA, afecte de tal manera su estructura secundaria que aumente o disminuya su disponibilidad para la maquinaria de procesamiento, resultando en cambios en los niveles de expresión de los miRNAs maduros. Estos cambios tendrían un impacto directo sobre la tasa de silenciamiento de los mRNAs blancos, que al estar más o menos silenciados promoverían un desequilibrio que aportaría con la transformación celular. / Worldwide, breast cancer (CM) is the most common and the leading cause of cancer death in women (14%), representing 23% of all new cancer cases. In Chile, it is the leading cause of cancer death in women, and mortality from CM, has been increasing in the last two decades. Because of this, it is appropriate to conduct studies to better understand their etiological bases, to take measures to prevention and early detection. In the literature there are various publications regarding coding genes that increase susceptibility to CM. This is the case of BRCA1 / 2, ATM, PALB2 among other genes, however in recent years there has been more attention to the influence that may have non-coding sequences on the risk of developing CM, specifically there is great interest in miRNAs, and polymorphisms present in them, which could be the cause of increased risk for CM. It has been shown that the presence of SNPs in the sequences of precursors or mature miRNAs affects maturation and processing of these small RNAs, as well as the silencing of their targets mRNAs, proposing this mechanism as responsible for the development of various diseases among CM them. In this work the allele and genotype frequencies of three SNPs (rs2910164, rs3764444 and rs11614913) present in the miRNAs 146a and miRNA-499 and miRNA-196 respectively, and its association with increased susceptibility to CM in Chilean women were analyzed. The results demonstrate that the SNPs present in both the miRNA-499 and miRNA-196, decrease the risk of developing CM and act as potential protective factors for the disease. By contrast, the SNP present in the miRNA-146a was associated with increased risk for women with CM CM sporadic, without family history of the disease, while in patients with family history was shown to be a protective factor. These results show the biological complexity that would be behind each type of CM, and the very different effects that miRNAs may have in different cellular contexts. To study the biological functionality that might be present in the pre miRNA- SNP 146a, this fragment was cloned from patients for the risk allele and control subjects, transforming later to study its effect in vitro by transfection into cells human breast.Despite not studied, it is expected that a change in the sequence of a miRNA precursor, so affecting its secondary structure to increase or decrease their availability for processing machinery, resulting in changes in the expression levels mature miRNAs. These changes may have a direct impact on the rate of silencing targets mRNAs, which being more or less silenced would promote an imbalance that would contribute to tumor cell transformation.

Made available in DSpace on 2016-08-10T10:38:51Z (GMT). No. of bitstreams: 1 PAULA APARECIDA BORGES PERES.pdf: 1092863 bytes, checksum: 6b1ba024090a288ed778814bb2668c7f (MD5) Previous issue date: 2012-08-31 / Despite its obscure aetiopathology, fibromyalgia is defined by diffuse musculoskeletal pain and not joint, and heightened sensitivity to palpation of certain muscle points, mainly affecting women, in a ratio of 6 to 10 women for every man. Several studies have demonstrated the role of polymorphisms of genes serotonergic, dopaminergic and catecholaminergic in the etiology of fibromyalgia. Thus, genetic factors may be determinants in the pathogenesis of fibromyalgia and some environmental factors may trigger fibromyalgia in genetically predisposed individuals. In this context, it seems that the gene polymorphism T102C serotonin receptor (5-HT2A) is relevant in susceptibility to fibromyalgia. The objective of this study was to perform a metaanalysis in order to investigate the association between polymorphism of the serotonin receptor gene (5-HT2A), the T102C SNP in susceptibility to fibromyalgia. Five studies, between the years 1999 to 2011, about 5-HT2AT102C polymorphism in fibromyalgia were selected and used for making a meta-analysis. The epidemiological profile of fibromyalgia patients revealed a mean age of 46.7 (+ 5.9) years, with extremes ranging from 21 to 77 years. The proportion between genders showed a difference of approximately 7 women for every man diagnosed fibromyalgia. The average time in which patients suffering from fibromyalgia syndrome is 7.4 (+ 2.9) years. Allele frequencies for T and C, the gene for 5- HT2AT102C were, respectively, for patients: 337 (43.1%) and 445 (56.9%) and for the controls: 362 (51.6%) and 340 (48.4%), indicating a predominance of the C allele in patients with fibromyalgia (p=0.0013). When evaluating the genotypic frequencies, we found: 73 (18.7%) TT, 191 (48.8%) and TC 127 (32.5%) CC. The control group: 98 (27.9%) TT, 166 (47.3%) and TC 87 (24.8%) CC. The CC genotype appears more frequently in the patients fibromyalgia patients (p=0.0046). A meta-analysis generated a universe of simultaneous evaluation of 742 individuals (391 fibromyalgia patients and 351 controls). The applied tests indicated no significant differences between the case and control groups. Thus, the result of the meta-analysis suggests no correlation between polymorphism in question and susceptibility to fibromyalgia. We suggest the use of a broad panel of SNPs with the intention of increasing the chances of finding an association between genetic polymorphisms and susceptibility to fibromyalgia. / Apesar de sua etiopatologia obscura, a fibromialgia é definida por dores musculoesqueléticas difusas e não articulares e sensibilidade a palpação exacerbada em determinados pontos musculares, afetando principalmente mulheres, numa proporção de 6 a 10 mulheres para cada homem. Vários estudos têm demonstrado o papel relevante dos polimorfismos de genes serotoninérgicos, dopaminérgicos e catecolaminérgicos na etiologia da fibromialgia. Desta forma, fatores genéticos podem ser determinantes na patogênese da fibromialgia e alguns fatores ambientais podem desencadear a fibromialgia em indivíduos geneticamente predispostos. Neste contexto, parece que o polimorfismo T102C do gene do receptor da serotonina (5-HT2A) pode ser relevante na suscetibilidade à fibromialgia. Assim, o objetivo do presente trabalho foi o de realizar uma meta-análise com o intuito de investigar a associação entre o polimorfismo do gene do receptor da serotonina (5- HT2A), no SNP T102C, na suscetibilidade à fibromialgia. Cinco estudos, entre os anos de 1999 a 2011, sobre o polimorfismo 5-HT2AT102C em fibromialgia foram selecionados e utilizados para a confecção de uma meta-análise. O perfil epidemiológico dos pacientes fibromiálgicos revelou uma idade média de 46,7 (+ 5,9) anos, com os extremos variando de 21 a 77 anos. Adiconalmente, a proporção entre gêneros apontou uma diferença de aproximadamente 7 mulheres com fibromialgia para cada homem diagnosticado. O tempo médio em que os pacientes sofrem da síndrome fibromiálgica é de 7,4 (+ 2,9) anos. As frequências alélicas para T e C, para o gene 5-HT2AT102C, foram, respectivamente, para os pacientes: 337 (43,1%) e 445 (56,9%) e para os controles: 362 (51,6%) e 340 (48,4%), indicando um predomínio do alelo C em pacientes com fibromialgia (p=0,0013). Ao avaliar as frequências genotípicas, encontrou-se: 73 (18,7%) TT, 191 (48,8%) TC e 127 (32,5%) CC. No grupo controle foram: 98 (27,9%) TT, 166 (47,3%) TC e 87 (24,8%) CC. O genótipo CC aparece em maior frequência no grupo dos pacientes fibromiálgico (p=0,0046). A meta-análise gerou um universo de avaliação simultânea de 742 indivíduos (391 pacientes com fibromialgia e 351 controles). Os testes aplicados não indicaram diferenças significativas entre os grupos caso e controle. Assim, o resultado da meta-análise sugere ausência de correlação entre o polimorfismo em questão e a suscetibilidade à fibromialgia. Sugerimos a utilização de um amplo painel de SNPs com a intenção de aumentar as chances de se encontrar associação entre polimorfismos gênicos e suscetibilidade à fibromialgia.