RESUMEN
This paper introduces the reader to the field of liquid biopsies and cell-free nucleic acids, focusing on circulating tumor DNA (ctDNA) in breast cancer (BC). BC is the most common type of cancer in women, and progress with regard to treatment has been made in recent years. Despite this, there remain a number of unresolved issues in the treatment of BC; in particular, early detection and diagnosis, reliable markers of response to treatment and for the prediction of recurrence and metastasis, especially for unfavorable subtypes, are needed. It is also important to identify biomarkers for the assessment of drug resistance and for disease monitoring. Our work is devoted to ctDNA, which may be such a marker. Here, we describe its main characteristics and potential applications in clinical oncology. This review considers the results of studies devoted to the analysis of the prognostic and predictive roles of various methods for the determination of ctDNA in BC patients. Currently known epigenetic changes in ctDNA with clinical significance are reviewed. The possibility of using ctDNA as a predictive and prognostic marker for monitoring BC and predicting the recurrence and metastasis of cancer is also discussed, which may become an important part of a precision approach to the treatment of BC.
Asunto(s)
Neoplasias de la Mama , Ácidos Nucleicos Libres de Células , ADN Tumoral Circulante , Humanos , Femenino , ADN Tumoral Circulante/genética , ADN Tumoral Circulante/análisis , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Pronóstico , Biopsia Líquida/métodos , Ácidos Nucleicos Libres de Células/genética , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/análisis , MutaciónRESUMEN
Atopic dermatitis (AD) is a worldwide disease with a complex aetiology. Both genetic and environmental factors cause a predisposition to AD. DNA methylation may be an additional predisposing factor. The goal of our study was to investigate genome-wide methylation profiles of skin from patients with AD and healthy persons. This case-control study included 12 AD patients and 6 healthy volunteers. DNA methylation levels in skin samples were analysed using the Illumina Infinium HumanMethylation450 BeadChip. We found that the methylation profile of skin from patients with AD was significantly different from that of healthy controls. Differential DNA methylation was observed for genes involved in a number of AD-related processes including regulation of the immune response, activation of lymphocytes, cell proliferation, apoptosis and differentiation of the epidermis. Our study indicates the involvement of epigenetic regulation in the development of atopic dermatitis.
Asunto(s)
Metilación de ADN , ADN/química , Dermatitis Atópica/genética , Adulto , Estudios de Casos y Controles , Epigénesis Genética , Femenino , Genoma , Humanos , Masculino , Regiones Promotoras Genéticas , Piel , Adulto JovenRESUMEN
CONTEXT: Increased oxidative stress is a significant part of pathogenesis of smoking-related cancer. AIM: The study aims to investigate changes in antioxidant status induced by chronic cigarette smoking in cancer patients and healthy subjects. SETTING AND DESIGN: We examined the venous blood samples of 54 healthy subjects, both smokers (25) and non-smokers and of 50 patients with smoking-related cancer, both smokers (34) and non-smokers. MATERIALS AND METHODS: We measured the activities of five antioxidant (AO) enzymes: glutathione peroxidase, glutathione transferase (GST), glutathione reductase, superoxide dismutase and catalase in the blood of 50 cancer patients and 54 healthy persons. Damage to cellular structures (level of malonic dialdehyde, micro viscosity of erythrocyte membranes, number of leukocyte DNA breaks) was determined. Statistical analysis of results obtained was performed using conventional and multi-factorial statistical methods. RESULTS: Statistically significant increase in GST activity and DNA breaks, but decrease of membranes micro viscosity in cancer patients, compared with healthy subjects were obtained. In the cancer patients, no influence of smoking on studied parameters was found. Correlations of parameters within cancer patients and healthy subjects group did not coincide with each other. CONCLUSIONS: Changes of AO status parameters and oxidative damages in cell structures are related to tumor processes indicating the augmentation of oxidative stress in human blood. This study demonstrated potential applicability of a statistical model based on the evaluated biomarkers of oxidative stress to determine a smoking-induced harm of cancer incidence in healthy subjects.