CHARACTERIZATION OF DNA METHYLATION CHANGES IN THE PERIPHERAL BLOOD OF COCAINE AND CRACK DEPENDENTS

Background Abuse and dependence on cocaine and its smoked form, crack, is an important public health problem. To better understand the interaction between genes and the environment, we analyzed methylation changes in the peripheral blood of cocaine/crack dependents. Methods The DNA methylation pattern in the peripheral blood of 23 cocaine and crack dependents and 24 healthy control subjects, all males with an age range of 23 to 29 years, were characterized in the Illumina Infinium HumanMethylation450 BeadChip arrays. After identifying the differentially methylated positions (DMPs) (ChAMP and RnBeads), the closest genes were annotated and functionally explored under a network perspective using STRING. These networks were annotated for biological processes and cellular signaling pathways. Results ChAMP revealed 249 DMPs, being 108 hypermethylated and 141 hypomethylated (adjP Discussion Genes related to changes in the methylation in the peripheral blood probably associated with the use of crack were enriched for signaling pathways and biological processes related to chromatin regulation. These results could help to understand the mechanisms involved in the interaction between biological and environmental factors of abuse/dependence behavior, mainly towards cocaine/crack abuse.