Efecto de Tropaeolum Tuberosum o "Mashua" (tropaeolaceae) sobre la expresión génica relacionada a espermatogénesis en ratón

Introducción: Tropaeolum tuberosum, conocido comomashua, es un tubérculo andino que tiene un valor tanto económico como nutritivo para las poblaciones de pocos recursos. Se cree que afecta la fertilidad masculina, porque los hombres andinos lo relacionan con impotencia y disminución de la capacidad fecundante. Estudios hechos en ratas que se alimentaron con mashua demostraron que hubo un 45% de decrecimiento de la tasa testosterona/dihidrotestosterona. El efecto de esta planta en la reproducción está relacionada a su contenido de isotiocianatos, compuestos que se unen covalentemente a las proteínas, las cuales pueden estar directa o indirectamente involucradas en el proceso espermatogénico. El propósito de esta investigación fue evaluar el efecto del extracto acuoso de la mashua sobre la espermatogénesis y la fisiología reproductiva de ratones. Métodos: Se evaluaron los parámetros morfofuncionales in vivo de espermios de ratones (espermatograma) y se cuantificó la expresión de: Cytochrome P450 17α-hydroxylase/17,20-lyase, proteína reguladora de esteroidogénesis aguda, ciclina y protamina, relacionados a la espermatogénesis. Resultados: A los 7, 14 y 21 días de dosificación, se vio afectado el conteo de espermatozoides, así como su motilidad progresiva (MP); por otra parte, se observó un retardo en la maduración de los mismos. En cuanto a la expresión génica, no se encontró diferencias significativas entre la expresión de los dos genes estudiados (cytochrome P450 17α-hydroxylase/17,20-lyase, ciclina). Conclusión: El efecto de la mashua no se da a nivel de la expresión de los genes involucrados en la espermatogénesis, sino a nivel de sus funciones como proteína.

Introduction: Tropaeolum tuberosum, known as "mashua" is an Andean tuber that holds both economic and nutritional value for low-income populations. It is believed that it affects male fertility because Andean men associate it with impotence and decreased fertility. Studies conducted on rats fed with "mashua" showed that there was a 45% decrease in the testosterone/dihydrotestosterone ratio. The effect of this plant on reproduction is related to its content of isothiocyanates, compounds that covalently bind to proteins, which may be directly or indirectly involved in the spermatogenic process. The purpose of this research was to evaluate the effect of the aqueous extract of "mashua" on spermatogenesis and reproductive physiology of mice. Methods: In vivo morphofunctional parameters of mouse sperm (spermatogram) were evaluated and the expression of Cytochrome P450 17α-hydroxylase/17,20-lyase, acute steroidogenesis regulatory protein, cyclin, and protamine related to spermatogenesis was quantified. Results: The results indicated that at 7, 14 and 21 days of dosing, the sperm count was affected, as well as their progressive motility (PM), on the other hand, a delay in their maturation was observed. Regarding gene expression, no significant differences were found between the expression of the two genes studied (Cytochrome P450 17α-hydroxylase/17,20-lyase, Cyclin). Conclusion: The effect of "mashua" does not occur at the level of gene expression involved in spermatogenesis, but at the level of its functions as a protein.

Larynx cancer: search for molecular markers

Introduction: Despite the advances in the understanding and treatment of the Larynx squamous cell carcinoma (LSCC), the survival has not changed in the last 30 years. Objective: In this study, we search for a better understanding of the pattern of genic expression of LSCC. Methods: Thirty-two tumor samples were collected from patients submitted to LSCC resection. The samples were submitted to cDNA microarray analysis to identify LSCC target. Results: The comparison of gene expression between early and advanced stages revealed 30 genes with significant differential expression. RT-qPCR validation experiments confirmed significant expression of only two genes (TMEM56 and SEC14L2) from eight selected. Comparing adjacent normal and tumor tissues, 69 genes showed statistically significant expression (mean ratio of 5.5), and 30 of them were up-regulated in tumor tissues. Gene expression validation by RT-qPCR showed SPRR2G and S100A7A as the most expressed in tumor tissue. Conclusion: The results demonstrate different pattern of expression, specially among tumor and non neoplastic tissue. The limitations to improve survival in larynx cancer justify studies focusing on search for molecular markers of prognosis and possible targeted therapy on LSCC.

Efecto de las nanopartículas industriales TiO 2 , SiO 2 y ZnO sobre la viabilidad celular y expresión génica en médula ósea roja de mus musculus / Effect of the Industrial Nanoparticles TiO 2 , SiO 2 and ZnO on Cell Viability and Gene Expression in Red Bone Marrow of Mus Musculus

RESUMEN Objetivos Evaluar el efecto de las nanopartículas de ZnO, TiO2 y SiO2 sobre la viabilidad celular y la expresión génica de las interleuquinas 7 y 3 y del factor estimulante de colonias de granulocito - macrófago (GM-CSF) en Mus musculus. Materiales y métodos Se extrajo médula ósea roja de cinco roedores (Balb/c) para el estudio de viabilidad celular mediante la prueba de MTT. Por otro lado, grupos cinco roedores fueron inoculados vía intraperitoneal con dosis de 0,5; 1; 2,5; 5 y 10 mg/kg de nanopartículas de ZnO y SiO2 y de 5; 10; 15; 20 y 25 mg/kg de nanopartículas de TiO2, 30 h después, se obtuvo el ARN a partir de la médula ósea roja para los análisis de expresión génica empleando las técnicas de PCR y RT-PCR cuantitativa. Resultados Las nanopartículas de ZnO y SiO2 redujeron la viabilidad celular de una manera dosis-dependiente en un 37 y 26%, respectivamente, a partir de una dosis de 1 mg/kg. En cuanto al efecto sobre la expresión génica, a las dosis 5 y 10 mg/kg, las nanopartículas de TiO2 redujeron en mayor porcentaje la expresión de las interleuquinas 7 y 3 (55,3 y 70,2% respectivamente), con respecto a la expresión del GM-CSF, el mayor porcentaje de reducción lo produjo las nanopartículas de SiO2 (91%). Las nanopartículas de ZnO redujeron a partir de las dosis de 20 y 25 mg/kg. Conclusiones Las nanopartículas de ZnO, SiO2 y TiO2 alteran la viabilidad celular y la expresión génica en la médula ósea de ratón.

ABSTRACT Objectives To evaluate the effect of ZnO, TiO2 and SiO2 nanoparticles on cell viability and expression of the interleukin 7, interleukin 3, and granulocyte-macrophage colony stimulating factor (GM-CSF) genes in Mus musculus. Material and methods Red bone marrow was extracted from five Balb/c mice for the analysis of cell viability using the MTT test. The mice were divided into two groups of five each: one group was inoculated intraperitoneally with 0.5, 1.0, 2.5, 5.0, and 10 mg/kg of ZnO and SiO2 nanoparticles, respectively, and the other group was inoculated with 5.0, 10.0, 15.0, 20.0, and 25 mg/kg of TiO2 nanoparticles, respectively. Thirty hours later, RNA was extracted from the red bone marrow of the mice in both groups for gene expression analysis using quantitative PCR and RT-PCR. Results ZnO and SiO2 nanoparticles reduced cell viability in a dose-dependent manner by 37% and 26%, respectively, starting at a dose of 1 mg/kg. TiO2 nanoparticles at 5 mg/kg and 10 mg/kg reduced the gene expression of interleukins 7 and 3 by 55.3% and 70.2%, respectively, and SiO2 nanoparticles caused the greatest decrease (91%) in the expression of GM-CSF. ZnO nanoparticles reduced the expression of GM-CSF starting at doses of 20 mg/kg and 25 mg/kg. Conclusions ZnO, SiO2 and TiO2 nanoparticles affect cell viability and gene expression in the mouse bone marrow.

Utilização de biomarcadores de genotoxicidade e expressão gênica na avaliação de trabalhadores de postos de combustíveis expostos a vapores de gasolina / Use of genotoxicity biomarkers and gene expression on the evaluation of gas station attendants exposed to gasoline fumes

Resumo Introdução: a avaliação de uma exposição mensura sua intensidade, frequência e duração, podendo detectar danos precoces que, se ignorados, podem evoluir para um quadro nocivo. Nos campos da saúde ambiental e ocupacional, os biomarcadores de genotoxicidade tem sido largamente utilizados para essa avaliação. Objetivo: identificar, descrever e discutir os principais bioindicadores de genotoxicidade e seu uso conjunto com técnicas de avaliação de expressão gênica em estudos de exposição ocupacional ao benzeno em postos de revenda de combustíveis (PRC). Métodos: revisão bibliográfica de trabalhos publicados entre 1995 e 2015. Resultados: as técnicas identificadas foram: ensaio cometa, estresse oxidativo, micronúcleos, aberrações cromossômicas, polimorfismos, adutos de DNA e proteínas, fatores epigenéticos e expressão gênica. Foi observado que testes de danos genéticos e epigenéticos são utilizados em frentistas de PRC que participam de programas de saúde do trabalhador ou de pesquisas, embora um baixo número de publicações sobre o tema tenha sido identificado. Esse fato talvez possa ser explicado pelos poucos países onde a profissão persiste e pelas limitações para o desenvolvimento de pesquisas nesses países. Conclusão: os bioindicadores de genotoxicidade e as técnicas de expressão gênica são úteis na detecção de dano precoce desta exposição ocupacional e devem ser avaliados em conjunto.

Abstract Introduction: an exposure evaluation measures its intensity, frequencyand duration, detecting premature damage that, if ignored, might develop into a harmful framework. On environmental and occupational health fields, genotoxicity biomarkers have been widely used for this evaluation. Objective: to identify, describe and discuss main genotoxicity biomarkers and their use together with gene expression evaluation techniques in studies concerning occupational exposure to benzene in gas stations (GS). Methods: bibliographical review of studies published between 1995 and 2015. Results: the following techniques were identified: comet assay, oxidative stress, micronuclei, chromosomal aberrations, polymorphisms, DNA and protein adducts, epigenetic factors and gene expression. We observed that genetic and epigenetic damage tests are used in gas station attendants who participate in worker’s health programs or in researches, although a short number of publications on the theme have been identified. This can be explained by the small number of countries where such job still exists and by the limitations for developing research in such countries. Conclusion: genotoxicity biomarkers and gene expression techniques are useful for detecting the premature damage resulting from this occupational exposure and must be jointly evaluated.

Ácido fólico: efeitos paradoxais na promoção da hepatocarcinogênese em ratos / Folic acid: paradoxical effects during promotion of hepatocarcinogenesis in rats

A suplementação com ácido fólico (AF) apresenta efeitos quimiopreventivos, porém, pode aumentar o risco de desenvolvimento e acelerar a progressão do câncer se ocorrer em doses elevadas ou após a ocorrência de lesões pré-neoplásicas (LPN). O AF é essencial na síntese de novo de purinas e timidalato e consequentemente na síntese, replicação e reparo do DNA, proliferação celular e apoptose. Assim, a deficiência pode implicar em danos ao DNA e erros na sua replicação e reparo, processos importantes na carcinogênese, onde as células apresentam taxas de replicação e divisão aceleradas, e é possível que a suplementação module estes processos. Além disso, como AF ocupa uma posição de destaque no metabolismo dos grupamentos metila pode exercer efeitos sobre a hipometilação global do DNA e o aumento da expressão de proto-oncogenes como o c-myc, fenômenos característicos da hepatocarcinogênese. Assim, objetivando-se avaliar os efeitos do AF na promoção da hepatocarcinogênese em ratos Wistar, desenvolveu-se o modelo do /"Hepatócito Resistente/" e administrou-se por entubação gástrica diariamente, durante 5 semanas, o AF (0,16; 0,32; ou 0,64 mg / 100 g de peso / dia) ou água (0,25 mL / 100 g de peso / dia). Então, avaliou-se as LPN hepáticas presentes visíveis à macroscopia e microscopia (GST-P), a proliferação celular (BrdU) e a apoptose (microscopia de fluorescência) no tecido hepático ao redor das LPN e nas LPN persistentes e em remodelação, a intensidade de danos ao DNA (/"Cometa/" alcalino), e o padrão de metilação global (Dot Blot) e a expressão do c-myc (RT-PCR) especificamente em LPN microdissecadas. Apesar de não ter alterado a incidência e multiplicidade das LPN, o tratamento com AF 0,32 mg / 100 g promoveu um aumento na porcentagem de lesões ≥ 1 mm e o com AF 0,64 mg / 100 g a diminuição na porcentagem dessa lesões com relação ao grupo água (p<0,05). De modo semelhante, observou-se na análise das LPN GST-P positivas que o AF 0,32 mg / 100 g promoveu aumento e...

Folic acid (FA) supplementation shows chemopreventive effects, however, it may increase the risk of development and accelerate cancer progression in case of high doses or after preneoplastic lesions (PNL) are established. FA is essential on de novo synthesis of purine and thymidalate and, consequently, on DNA synthesis, replication and repair, cell proliferation and apoptosis. Thus, its deficiency may cause DNA damage and replication and repair mistakes, important processes on carcinogenesis, where cells present high replication rates and accelerated division, and is possible that supplementation modulates these processes. Besides, as FA has a central role on methyl group metabolism, it may have effects on hepatocarcinogenesis peculiar events such as DNA global hypomethylation and on the increased expression of proto-oncogenes like c-myc. Objecting the evaluation of FA effects during hepatocarcinogenesis promotion in Wistar rats, the /"Resistant Hepatocyte/" model was developed and water (0.25 mL / 100 g BW / day) or FA (0.16; 0.32; or 0.64 mg / 100 g BW / day) were supplemented daily by gavage for 5 weeks. Then, hepatic PNL detected by macroscopy and microscopy (GST-P), cell proliferation (BrdU) and apoptosis (fluorescence microscopy) on surrounding tissue, persistent and remodeling PNL, DNA damage (alcaline Comet assay), DNA global methylation pattern (Dot Blot) and c-myc expression (RT-PCR) specifically in microdissected PNL were evaluated. Even though FA treatment was not able to change incidence and multiplicity of PNL, the treatment with 0.32 mg / 100 g of FA increased the percentage of lesions ≥ 1 mm whereas with 0.64 mg / 100 g of FA diminished the percentage of these lesions, compaired to the water group (p<0.05). Similarly, it could be observed in PNL positive GST-P analysis that FA 0.32 mg / 100 g enhanced and FA 0.64 mg / 100 g inhibited the carcinogenic process, although it was not possible to detect significant differences on number, size and…