Liquid biopsy of patients with advanced liver fibrosis reveals the association of methylation in CpGs and miRNAs expression with the degree of severity

Abstract

Introduction and Objective: This study aimed to assess whether the expression of specific miRNAs and the percentage of DNA methylation of the Peroxisomal Proliferator-Activated Receptors (PPAR) α, γ and δ genes in tissue and liquid biopsy from patients with advanced liver fibrosis (F3 and F4) is associated to the degree of severity. Materials and methods: Transjugular liver biopsy and liquid biopsy were collected from 23 patients with sustained viral response to the hepatitis C virus, with advanced residual fibrosis (F3 and F4). The percentage of methylation in CpG islands of the promoters of the PPARα, PPARγ and PPARδ genes and the expression levels of miRNAs were determined. Masson's trichrome hematoxylin-eosin staining was performed. DNA was extracted from tissues and plasma, and percent methylation was measured by pyrosequencing. Extraction and isolation of miRNAs from liver tissue were performed: miR-21, miR-34, miR-122, miR181b, miR192, miR-200a/b and their expression level compared to miR-16 was evaluated. The trial was approved by the research ethics committee, and informed consent was obtained. Results: Higher promoter methylation percentages were observed in patients with more severe degrees of fibrosis (F4), both in tissue and in liquid biopsy. In addition, overexpression of miRNAs was associated with the degree of fibrosis. Discussion: Epigenetic mechanisms (DNA methylation and microRNA expression) regulate the expression of multiple genes and their status may be a biomarker associated with the degree of fibrosis. Conclusion: Liquid biopsy is an effective and accessible method for evaluating the degree of fibrosis. Funding: The resources used in this study were from the hospital without any additional financing Declaration of interest: The authors declare no potential conflicts of interest.