MECANISMOS EPIGENÉTICOS NO DESENVOLVIMENTO DO CÂNCER

Abstract

Introduction: Epigenetics, a field of study dedicated to the mechanisms that regulate gene expression without modifying the DNA sequence, encompasses changes resulting from alterations in the DNA bases and the superstructure of their packaging. DNA, organized into repeating units called nucleosomes, forms a histone complex made up of H2A, H2B, H3 and H4. Modifications to these histone proteins can facilitate or hinder access to DNA by the replication and transcription machinery, impacting on gene expression patterns. These changes, although not permanent, can last for several generations and are susceptible to influences such as age, environment and specific disease states. Objective: To analyze the complexities of epigenetics, focusing on the mechanisms that regulate gene expression without modifying the DNA sequence. In addition, we sought to understand how changes in these mechanisms, especially those related to DNA methylation, histone modifications and genomic imprinting, are associated with the emergence of different types of cancer. Methodology: This is a literature review. Articles were obtained from the Scientific Electronic Library Online (SciELO), PubMed and Web of Science databases, using descriptors registered with Decs. Articles published between 2015 and 2023 in peer-reviewed journals were selected, with the languages considered being Portuguese and English. The analysis of the articles aimed to identify correlations between epigenetic mechanisms and cancer incidence, with an emphasis on persistent epigenetic changes over generations. Results: The results of this literature review indicate that alterations in DNA methylation at key sites in the genome are directly associated with the development of cancer. Recent literature highlights the potential of abnormal DNA methylation as a biomarker for cancer, highlighting the relevance of these epigenetic mechanisms in understanding neoplastic genesis. The analysis also revealed that factors such as histone modifications and genomic imprinting play a crucial role in this context. Final considerations: The importance of epigenetic mechanisms in the context of cancer has provided a comprehensive view of how these alterations contribute to the formation of neoplastic cells. Understanding these processes opens the door to the development of more sensitive diagnostic methods and more effective treatments. This study contributes to updating scientific knowledge by identifying recent relationships between epigenetic mechanisms and different types of cancer, offering valuable perspectives for future therapeutic approaches and early diagnosis.