“Disease-specific serum miRNA profiles may serve as biomarkers and might reveal
ID: 256712 • Letter: #
Question
“Disease-specific serum miRNA profiles may serve as biomarkers and might reveal potential new avenues for therapy. An HBV-specific serum miRNA profile associated with HBV surface antigen (HBsAg) particles has recently been reported, and AGO2 and miRNAs have been shown to be stably associated with HBsAg in serum. We identified HBV-associated serum miRNAs using the Toray 3D array system in 10 healthy controls and 10 patients with chronic hepatitis B virus (HBV) infection. 19 selected miRNAs were then measured by quantitative RT-PCR in 248 chronic HBV patients and 22 healthy controls. MiRNA expression in serum versus liver tissue was also compared using biopsy samples. To examine the role of AGO2 during the HBV life cycle, we analyzed intracellular co-localization of AGO2 and HBV core (HBcAg) and surface (HBsAg) antigens using immunocytochemistry and proximity ligation assays in stably transfected HepG2 cells. The effect of AGO2 ablation on viral replication was assessed using siRNA. Several miRNAs, including miR-122, miR-22, and miR-99a, were up-regulated at least 1.5 fold (P<2E-08) in serum of HBV-infected patients. AGO2 and HBcAg were found to physically interact and co-localize in the ER and other subcellular compartments. HBs was also found to co-localize with AGO2 and was detected in multiple subcellular compartments. Conversely, HBx localized non-specifically in the nucleus and cytoplasm, and no interaction between AGO2 and HBx was detected. SiRNA ablation of AGO2 suppressed production of HBV DNA and HBs antigen in the supernatant.”
https://www.ncbi.nlm.nih.gov/pubmed/23091627
1. What are miRNAs and how could they be used as biomarkers for disease?
Explanation / Answer
miRNAs are short non-coding RNA molecules (21-25 nucleotides) that function as negative, post-transcriptional, regulators of gene expression. They are released into the extracellular space. Their stability and presence in biofluids such as plasma make them easier to be detected by non-invasive and reliable methods, making them very appealing as quantifiable biomarkers for monitoring various diseases. miRNAs are crucial in cell physiology (development, proliferation, apoptosis, enzymatic processes, etc.). Their expression is altered in several diseases such as cancer so that they can be used in diagnosis, and clinical evaluations. miRNA signatures are specific for each human tissue and pathologic state and can be analysed in many biologic specimens and fluids. They also regulate drug responses making them useful in predictive diagnostics.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.