MicroRNA-182 Promotes Cell Migration by Targeting Programmed Cell Death 4 in Hepatocellular Carcinoma Cells

Specific and efficient knockdown of intracellular miRNA using partially neutralized phosphate-methylated DNA oligonucleic acid-loaded mesoporous silica nanoparticles

Antisense oligonucleotides (ASOs) are molecules used to regulate RNA expression by targeting specific RNA sequences. One specific type of ASO, known as neutralized DNA (nDNA), contains site-specific methyl phosphotriester (MPTE) linkages on the phosphate backbone, changing the negatively charged DNA phosphodiester into a neutralized MPTE with designed locations. While nDNA has previously been employed as a sensitive nucleotide sequencing probe for the PCR, the potential of nDNA in intracellular RNA regulation and gene therapy remains underexplored. Our study aims to evaluate the regulatory capacity of nDNA as an ASO probe in cellular gene expression. We demonstrated that by tuning MPTE locations, partially and intermediately methylated nDNA loaded onto mesoporous silica nanoparticles (MSNs) can effectively knock down the intracellular miRNA, subsequently resulting in downstream mRNA regulation in colorectal cancer cell HCT116. Additionally, the nDNA ASO-loaded MSNs exhibit superior efficacy in reducing miR-21 levels over 72 hours compared to the efficacy of canonical DNA ASO-loaded MSNs. The reduction in the miR-21 level subsequently resulted in the enhanced mRNA levels of tumour-suppressing genes PTEN and PDCD4. Our findings underscore the potential of nDNA in gene therapies, especially in cancer treatment via a fine-tuned methylation location.

The emerging role of MicroRNA-182 in tumorigenesis; a promising therapeutic target

A wide range of studies have indicated that microRNAs (miRNAs), a type of small single-stranded regulatory RNAs, are dysregulated in a different variety of human cancers. Therefore, they are expected to play important roles in tumorigenesis by functioning as oncogenic (oncomiRs) or tumor-suppressive miRNAs. Subsequently, their potential as diagnostic and therapeutic targets for malignancies has attracted attention in recent years. In particular, studies have revealed the aberrant expression of miR-182 through tumorigenesis and its important roles in various aspects of malignancies, including proliferation, metastasis, and chemoresistance. Accumulating reports have illustrated that miR-182, as a dual-role regulator, directly or indirectly regulates the expression of a wide range of genes and modulates the activity of various signaling pathways involved in tumor progression, such as JAK / STAT3, Wnt / β-catenin, TGF-β, and P13K / AKT. Therefore, considering the high therapeutic and diagnostic potential of miR-182, this review aims to point out the effects of miR-182 dysregulation on the signaling pathways involved in tumorigenesis.

MiR-182-5p Is Upregulated in Hepatic Tissues from a Diet-Induced NAFLD/NASH/HCC C57BL/6J Mouse Model and Modulates Cyld and Foxo1 Expression

Non-alcoholic fatty liver disease (NAFLD) is considered a relevant liver chronic disease. Variable percentages of NAFLD cases progress from steatosis to steatohepatitis (NASH), cirrhosis and, eventually, hepatocellular carcinoma (HCC). In this study, we aimed to deepen our understanding of expression levels and functional relationships between miR-182-5p and Cyld-Foxo1 in hepatic tissues from C57BL/6J mouse models of diet-induced NAFL/NASH/HCC progression. A miR-182-5p increase was detected early in livers as NAFLD damage progressed, and in tumors compared to peritumor normal tissues. An in vitro assay on HepG2 cells confirmed Cyld and Foxo1, both tumor-suppressor, as miR-182-5p target genes. According to miR-182-5p expression, decreased protein levels were observed in tumors compared to peritumor tissues. Analysis of miR-182-5p, Cyld and Foxo1 expression levels, based on datasets from human HCC samples, showed results consistent with those from our mouse models, and also highlighted the ability of miR-182-5p to distinguish between normal and tumor tissues (AUC 0.83). Overall, this study shows, for the first time, miR-182-5p overexpression and Cyld-Foxo1 downregulation in hepatic tissues and tumors from a diet-induced NAFLD/HCC mouse model. These data were confirmed by the analysis of datasets from human HCC samples, highlighting miR-182-5p diagnostic accuracy and demonstrating the need for further studies to assess its potential role as a biomarker or therapeutic target.

Self-assembled DNA nanostructure containing oncogenic miRNA-mediated cell proliferation by downregulation of FOXO1 expression

FOXO1 transcription factor not only limits the cell cycle progression but also promotes cell death as a tumor suppressor protein. Though the expression of FOXO1 is largely examined in breast cancer, the regulation of FOXO1 by miRNA is yet to be explored. In the current study, self-assembled branched DNA (bDNA) nanostructures containing oncogenic miRNAs were designed and transfected to the MCF7 cell line to decipher the FOXO1 expression. bDNA containing oncogenic miRNAs 27a, 96, and 182 synergistically downregulate the expression of FOXO1 in MCF7 cells. The down-regulation is evident both in mRNA and protein levels suggesting that bDNA having miRNA sequences can selectively bind to mRNA and inhibit translation. Secondly, the downstream gene expression of p21 and p27 was also significantly downregulated in presence of miR-bDNA nanostructures. The cell proliferation activity was progressively increased in presence of miR-bDNA nanostructures which confirms the reduced tumor suppression activity of FOXO1 and the downstream gene expression. This finding can be explored to design novel bDNA structures which can downregulate the tumor suppressor proteins in normal cells and induce cell proliferation activity to identify early-phase markers of cancer.

Circ_0091702 relieves lipopolysaccharide (LPS)-induced cell injury by regulating the miR-182/PDE7A axis in sepsis

Circular RNA (circRNA) plays an important role in the progression of sepsis. Circ_0091702 has been found to be an important regulator of sepsis progression, so its role and mechanism in sepsis progression deserve to be further explored. LPS could suppress cell viability, while enhance cell apoptosis and inflammation to induce cell injury. Circ_0091702 was downregulated in LPS-induced HK2 cells, and its overexpression alleviated LPS-induced cell injury. MiR-182 could be sponged by circ_0091702. Moreover, miR-182 inhibitor could relieve LPS-induced cell injury, and its overexpression also reversed the inhibition of circ_0091702 on LPS-induced cell injury. PDE7A was a target of miR-182, and its expression was reduced in LPS-induced HK2 cells. Additionally, silencing of PDE7A reversed the suppressive effect of circ_0091702 on LPS-induced cell injury. Our data suggested that circ_0091702 sponged miR-182 to regulate PDE7A, thereby alleviating LPS-induced cell injury in sepsis.