Role for DNA Methylation in the Regulation of miR-200c and miR-141 Expression in Normal and Cancer Cells

The microRNA-200 family participates in the maintenance of an epithelial phenotype and loss of its expression can result in epithelial to mesenchymal transition (EMT). Furthermore, the loss of expression of miR-200 family members is linked to an aggressive cancer phenotype. Regulation of the miR-200 family expression in normal and cancer cells is not fully understood.Epigenetic mechanisms participate in the control of miR-200c and miR-141 expression in both normal and cancer cells. A CpG island near the predicted mir-200c/mir-141 transcription start site shows a striking correlation between miR-200c and miR-141 expression and DNA methylation in both normal and cancer cells, as determined by MassARRAY technology. The CpG island is unmethylated in human miR-200/miR-141 expressing epithelial cells and in miR-200c/miR-141 positive tumor cells. The CpG island is heavily methylated in human miR-200c/miR-141 negative fibroblasts and miR-200c/miR-141 negative tumor cells. Mouse cells show a similar inverse correlation between DNA methylation and miR-200c expression. Enrichment of permissive histone modifications, H3 acetylation and H3K4 trimethylation, is seen in normal miR-200c/miR-141-positive epithelial cells, as determined by chromatin immunoprecipitation coupled to real-time PCR. In contrast, repressive H3K9 dimethylation marks are present in normal miR-200c/miR-141-negative fibroblasts and miR-200c/miR-141 negative cancer cells and the permissive histone modifications are absent. The epigenetic modifier drug, 5-aza-2′-deoxycytidine, reactivates miR-200c/miR-141 expression showing that epigenetic mechanisms play a functional role in their transcriptional control.We report that DNA methylation plays a role in the normal cell type-specific expression of miR-200c and miR-141 and this role appears evolutionarily conserved, since similar results were obtained in mouse. Aberrant DNA methylation of the miR-200c/141 CpG island is closely linked to their inappropriate silencing in cancer cells. Since the miR-200c cluster plays a significant role in EMT, our results suggest an important role for DNA methylation in the control of phenotypic conversions in normal cells

Individualizing therapy – in search of approaches to maximize the benefit of drug treatment (II)

Adjusting drug therapy to the individual, a common approach in clinical practice, has evolved from 1) dose adjustments based on clinical effects to 2) dose adjustments made in response to drug levels and, more recently, to 3) dose adjustments based on deoxyribonucleic acid (DNA) sequencing of drug-metabolizing enzyme genes, suggesting a slow drug metabolism phenotype. This development dates back to the middle of the 20(th )century, when several different drugs were administered on the basis of individual plasma concentration measurements. Genetic control of drug metabolism was well established by the 1960s, and pharmakokinetic-based individualized therapy was in use by 1973

Systemic inhibition of tumour angiogenesis by endothelial cell-based gene therapy

Angiogenesis and post-natal vasculogenesis are two processes involved in the formation of new vessels, and both are essential for tumour growth and metastases. We isolated endothelial cells from human blood mononuclear cells by selective culture. These blood outgrowth cells expressed endothelial cell markers and responded correctly to functional assays. To evaluate the potential of blood outgrowth endothelial cells (BOECs) to construct functional vessels in vivo, NOD-SCID mice were implanted with Lewis lung carcinoma cells subcutaneously (s.c.). Blood outgrowth endothelial cells were then injected through the tail vein. Initial distribution of these cells occurred throughout the lung, liver, spleen, and tumour vessels, but they were only found in the spleen, liver, and tumour tissue 48 h after injection. By day 24, they were mainly found in the tumour vasculature. Tumour vessel counts were also increased in mice receiving BOEC injections as compared to saline injections. We engineered BOECs to deliver an angiogenic inhibitor directly to tumour endothelium by transducing them with the gene for human endostatin. These cells maintained an endothelial phenotype and decreased tumour vascularisation and tumour volume in mice. We conclude that BOECs have the potential for tumour-specific delivery of cancer gene therapy

Vascular Remodeling in Health and Disease

The term vascular remodeling is commonly used to define the structural changes in blood vessel geometry that occur in response to long-term physiologic alterations in blood flow or in response to vessel wall injury brought about by trauma or underlying cardiovascular diseases.1, 2, 3, 4 The process of remodeling, which begins as an adaptive response to long-term hemodynamic alterations such as elevated shear stress or increased intravascular pressure, may eventually become maladaptive, leading to impaired vascular function. The vascular endothelium, owing to its location lining the lumen of blood vessels, plays a pivotal role in regulation of all aspects of vascular function and homeostasis.5 Thus, not surprisingly, endothelial dysfunction has been recognized as the harbinger of all major cardiovascular diseases such as hypertension, atherosclerosis, and diabetes.6, 7, 8 The endothelium elaborates a variety of substances that influence vascular tone and protect the vessel wall against inflammatory cell adhesion, thrombus formation, and vascular cell proliferation.8, 9, 10 Among the primary biologic mediators emanating from the endothelium is nitric oxide (NO) and the arachidonic acid metabolite prostacyclin [prostaglandin I2 (PGI2)], which exert powerful vasodilatory, antiadhesive, and antiproliferative effects in the vessel wall

¿Por qué se denuncian delitos patrimoniales ante la policía? Una evaluación empírica para el Perú

Abstract Peru has not only one of the highest victimization rates in Latin America (24%), but also the lowest rate of reported crimes (15%) (Latinobarometro, 2016) The purpose of this study was to identify the characteristics of the crimes and the characteristics of the individuals that predict the decision of reporting four different property crimes (burglary, auto theft, auto parts theft, and motorcycle theft). To this end, a seven-year survey of households at the national level in Peru was used (2010-2016). The estimations were made using multilevel mixed effects logistics regression, in order to control for characteristics of the environment that also influence the decision to report. Use of a weapon by the criminal is the factor that most increases the probability of reporting any of the four assessed crimes. Repeated victimization is also an important predictor, although for a lower number of crimes. Trust in the police is not associated to the decision to report. This is the first study to quantitatively analyze the factors that affect the decision to report in Peru. Its results are useful for a better understanding of the low reporting rates in the country.Resumo O Peru não apenas tem uma das taxas mais altas de vitimização em América Latina (24%), mas também a mais baixa em crimes denunciados (15%) (Latinobarómetro, 2016). Neste trabalho, o objetivo foi identificar as características do crime e as características individuais que predizem a decisão de denunciar quatro diferentes crimes patrimoniais (furto de casa, carro, autopeças e motocicleta). Para isso, foram utilizados sete anos de dados de uma pesquisa domiciliar nacional no Peru (2010-2016). As estimativas foram feitas usando regressão logística multinível de efeitos mistos a fim de controlar as características ambientais que também influenciam na decisão de denunciar. O uso de arma de fogo pelo delinquente é o fator que aumenta em maior proporção a probabilidade de denúncia de qualquer um dos quatro crimes avaliados. A vitimização repetida também é um indicador importante, embora para menos crimes. A confiança na polícia não está associada à decisão de denunciar. Este estudo é o primeiro a analisar quantitativamente os fatores que afetam a decisão de denunciar no Peru. Seus resultados são úteis para um melhor entendimento da taxa baixa de denúncias no país.Resumen Perú no solo tiene una de las mayores tasas de victimización en Latinoamérica (24%), sino también la menor en delitos denunciados (15%) (Latinobarómetro, 2016). En este trabajo, el objetivo fue identificar las características del crimen y las características individuales que predicen la decisión de denunciar cuatro delitos patrimoniales distintos (robo de hogares, de auto, de autopartes y de moto). Para ello, se emplearon siete años de una encuesta de hogares a nivel nacional en Perú (2010-2016). Las estimaciones se realizaron mediante regresión logística multinivel de efectos mixtos a fin de controlar las características del ambiente que también influyen en la decisión de denuncia. El uso de arma de parte del delincuente es el factor que eleva en mayor proporción la probabilidad de denunciar cualquiera de los cuatro delitos evaluados. La victimización reiterada es también un predictor importante, aunque para menos delitos. La confianza en la policía no está asociada a la decisión de denunciar. Este estudio es el primero que analiza cuantitativamente los factores que afectan la decisión de denunciar en el Perú. Sus resultados son útiles para un mejor entendimiento de la baja tasa de denuncias en el país