Interpreting the various associations of MiRNA polymorphisms with susceptibilities of cardiovascular diseases: Current evidence based on a systematic review and meta-analysis

miRNA-128 modulates bone neoplasms cells proliferation and migration through the WNT/β-catenin and EMT signal pathways

BACKGROUND

Bone neoplasms present poor prognosis due to recurrence and metastasis. Although the role microRNAs (miRNAs) in inhibiting growth and metastasis of bone neoplasms has been investigated, the underlying potential molecular mechanisms mediated by miRNA-128 (miR-218) for the invasiveness of bone neoplasms cells are still not completely understood. The purpose of this study was to identify the regulatory mechanisms of miR-218 in bone neoplasms cells.

METHODS

Western blotting, quantitative reverse transcription-polymerase chain reaction (qRT-PCR), Counting Kit-8 assay, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, luciferase activity assay immunofluorescence, and immunohistochemistry were used to analyze the regulatory effects of miR-218 on bone neoplasms cells.

RESULTS

Here, the results showed that transfection of miR-128 suppressed bone neoplasms cells proliferation, migration, and invasion. Genetic knockdown of miR-128 in bone neoplasms cells suppressed the activation of the Wnt/β-catenin and epithelial-mesenchymal transition (EMT) signaling pathways. Activation of Wnt or EMT blocked miR-128-inhibited cells proliferation and migration in bone neoplasms cells. Exogenously introduced miR-128 markedly inhibited tumor regeneration in bone neoplasms xenograft models.

CONCLUSIONS

These results define a tumor-regulated function for miR-128 in bone neoplasms by down-regulation of the Wnt/β-catenin and EMT signal pathways, which provided a potential target for bone neoplasms gene therapy.

miR-27b Modulates Insulin Signaling in Hepatocytes by Regulating Insulin Receptor Expression

Insulin resistance (IR) is one of the key contributing factors in the development of type 2 diabetes mellitus (T2DM). However, the molecular mechanisms leading to IR are still unclear. The implication of microRNAs (miRNAs) in the pathophysiology of multiple cardiometabolic pathologies, including obesity, atherosclerotic heart failure and IR, has emerged as a major focus of interest in recent years. Indeed, upregulation of several miRNAs has been associated with obesity and IR. Among them, miR-27b is overexpressed in the liver in patients with obesity, but its role in IR has not yet been thoroughly explored. In this study, we investigated the role of miR-27b in regulating insulin signaling in hepatocytes, both in vitro and in vivo. Therefore, assessment of the impact of miR-27b on insulin resistance through the hepatic tissue is of special importance due to the high expression of miR-27b in the liver together with its known role in regulating lipid metabolism. Notably, we found that miR-27b controls post-transcriptional expression of numerous components of the insulin signaling pathway including the insulin receptor (INSR) and insulin receptor substrate 1 (IRS1) in human hepatoma cells. These results were further confirmed in vivo showing that overexpression and inhibition of hepatic miR-27 enhances and suppresses hepatic INSR expression and insulin sensitivity, respectively. This study identified a novel role for miR-27 in regulating insulin signaling, and this finding suggests that elevated miR-27 levels may contribute to early development of hepatic insulin resistance.

miR-196a2 (rs11614913) polymorphism is associated with coronary artery disease, but not with in-stent coronary restenosis

OBJECTIVE

The aim of the study was to evaluate the association of miRNA-146a G/C (rs2910164), and miRNA-196a2 C/T (rs11614913) polymorphisms with the presence of coronary artery disease (CAD) and/or restenosis in patients with coronary stent.

MATERIALS AND METHODS

The polymorphisms were determined in 218 patients with CAD who underwent coronary artery stenting (66 with restenosis and 152 without restenosis) and 611 healthy controls using 5' exonuclease TaqMan assays.

RESULTS

The distribution of both polymorphisms was similar in patients with and without restenosis. However, when the whole group of patients (with and without restenosis) was compared to healthy controls, under co-dominant, dominant and additive genetic models, the T allele of the miRNA-196a2 C/T (rs11614913) polymorphism was associated with increased risk of CAD (OR = 2.18, P_co-dom = 0.006, OR = 1.86, P_dom = 0.002, and OR = 1.52, P_add = 0.002, respectively). All models were adjusted for age, type 2 diabetes mellitus, dyslipidemia, hypertension and smoking habit. The "GT" haplotype was associated with increased risk of developing CAD (OR = 1.36, P = 0.046).

CONCLUSIONS

Our data suggests that the T allele of the miRNA-196a2 C/T (rs11614913) polymorphism is associated with the risk of developing CAD, but no association with restenosis was observed.