Multivariate analysis of clinicopathological and prognostic significance of miRNA 106b~25 cluster in gastric cancer

MiR-144/451a cluster synergistically modulates growth and metastasis of Oral Carcinoma

OBJECTIVES

MicroRNA (miRNA) clusters co-transcribe and function in a coordinated fashion mediating synergistic or antagonistic regulatory effects. MiR-144 and miR-451a are deregulated in various cancers but the combined regulatory role of miR-144/451a cluster in oral squamous cell carcinoma (OSCC) remains unexplored. In the present study, we studied the synergistic effect of miR-144/451a cluster on oral cancer progression.

MATERIALS AND METHODS

miR-144 and miR-451a expression was explored in OSCC cell lines by quantitative real-time PCR (qRT-PCR). Proliferation, wound healing, migration and invasion, spheroid formation, and colony formation assays were performed after transfection with miR-144-3p, miR-451a, miR-144-5p, and co-expressed miR-144/451a. Expression of putative target genes was analyzed using qRT-PCR and Western blotting.

RESULTS

miR-144 and miR-451a were downregulated in all cell lines. The cell viability and stemness of cancer cell lines were unaltered when treated with miRNA mimics. However, co-expressed miR-144/451a significantly reduced the migratory, invasive, and clonogenic potential of cells than individual miRNAs.

CONCLUSION

miR-144/451a cluster functions as a tumor suppressor in OSCC by inhibiting cancer cell invasion, migration, and clonogenic potential.

Extracellular microRNAs in human circulation are associated with miRISC complexes that are accessible to anti-AGO2 antibody and can bind target mimic oligonucleotides

MicroRNAs (miRNAs) function cell-intrinsically to regulate gene expression by base-pairing to complementary mRNA targets while in association with Argonaute, the effector protein of the miRNA-mediated silencing complex (miRISC). A relatively dilute population of miRNAs can be found extracellularly in body fluids such as human blood plasma and cerebrospinal fluid (CSF). The remarkable stability of circulating miRNAs in such harsh extracellular environments can be attributed to their association with protective macromolecular complexes, including extracellular vesicles (EVs), proteins such as Argonaut 2 (AGO2), or high-density lipoproteins. The precise origins and the potential biological significance of various forms of miRNA-containing extracellular complexes are poorly understood. It is also not known whether extracellular miRNAs in their native state may retain the capacity for miRISC-mediated target RNA binding. To explore the potential functionality of circulating extracellular miRNAs, we comprehensively investigated the association between circulating miRNAs and the miRISC Argonaute AGO2. Using AGO2 immunoprecipitation (IP) followed by small-RNA sequencing, we find that miRNAs in circulation are primarily associated with antibody-accessible miRISC/AGO2 complexes. Moreover, we show that circulating miRNAs can base-pair with a target mimic in a seed-based manner, and that the target-bound AGO2 can be recovered from blood plasma in an ∼1:1 ratio with the respective miRNA. Our findings suggest that miRNAs in circulation are largely contained in functional miRISC/AGO2 complexes under normal physiological conditions. However, we find that, in human CSF, the assortment of certain extracellular miRNAs into free miRISC/AGO2 complexes can be affected by pathological conditions such as amyotrophic lateral sclerosis.

MicroRNA-148a-3p inhibits cancer progression and is a novel screening biomarker for gastric cancer

PURPOSE

Dysregulation of miR-148a-3p in gastric cancer was reported. However, the diagnostic potential and biological function of miR-148a-3p in gastric cancer progression is not fully studied.

METHODS

Bioinformatics analysis and RT-qPCR assay were performed to analyze the expression of miR-148a-3p in gastric cancer tissues and plasma of gastric cancer patients. Receiver operating characteristic curve analysis was performed to analyze the diagnostic value of miR-148a-3p. In vitro proliferation, apoptosis, migration, invasion, sphere formation assay and Western blotting assay were performed to evaluate the biological function of miR-148a-3p in gastric cancer progression.

RESULTS

miR-148a-3p was significantly down-regulated in both gastric cancer patients' tissue and plasma samples. Plasma miR-148a-3p showed promising efficacy for gastric cancer diagnosis. Overexpression of miR-148a-3p could inhibit the proliferative phenotype, metastatic phenotype, and cancer stem-like properties of gastric cancer cells.

CONCLUSIONS

miR-148a-3p inhibits cancer progression and is a novel diagnostic biomarker for gastric cancer.

MiR-96 promotes apoptosis of nucleus pulpous cells by targeting FRS2

This study aimed to investigate the molecular mechanism by which microRNA (miR)-96 regulates the progression of intervertebral disc degeneration (IDD). The expression of miR-96 in normal intervertebral discs and in IDD was detected by performing reverse transcription-quantitative PCR. CCK8 assay was applied to examine the proliferation of nucleus pulpous (NP) cells and flow cytometry was used to evaluate the cell apoptosis and cell cycle profile. In addition, the immunofluorescence analysis was employed to detect cell proliferation. The expressions of proteins were assessed by western blot analysis. TargetScan and miRDB were used to predict the target genes of miR-96. The results indicated that miR-96 expression was upregulated in IDD compared with normal intervertebral discs. Overexpression of miR-96 could significantly inhibit the proliferation of NP cells via inducing apoptosis and G1 arrest. In addition, fibroblast growth factor receptor substrate 2 (FRS2) was identified as the target of miR-96 and overexpression of FRS2 could revere the effect of miR-96 mimics in NP cells. Therefore, these findings demonstrated that miR-96 plays a critical role during the progression of IDD and miR-96 may serve as a target for the treatment of IDD.

Effects of miR-330-3p on Invasion, Migration and EMT of Gastric Cancer Cells by Targeting PRRX1-Mediated Wnt/β-Catenin Signaling Pathway

BACKGROUND

miRNA, as a biological marker, had more and more attention in recent years due to the important role it plays in cancer. Currently, there are extensive studies on miRNAs, among which miR-330-3p is reported to be implicated in the pathophysiological processes of various cancers. However, little progress has been made in the mechanism of miR-330-3p in gastric cancer.

OBJECTIVE

To explore the expression and relevant mechanism of miR-330-3p and PRRX1 in gastric cancer (GC).

METHODS

Forty-five GC patients (study group), from whom paired GC and paracancerous tissues were collected, and another 45 healthy subjects (control group) who underwent physical examination during the same period were enrolled. In addition, GC cells and human gastric mucosa cells were purchased, and miR-330-3p-mimics, miR-330-3p-inhibitor, miR-NC, si-PRRX1, and sh-PRRX1 were transfected into MKN45, SGC7901 cell. QRT-PCR was employed to assess the miR-330-3p and PRRX1 expressions in the samples, and the cell expressions of PRRX1, GSK-3β, p-GSK-3β, β-catenin, p-β-catenin, cyclin D1, N-cadherin, E-cadherin and vimentin were evaluated by Western blot (WB). MTT, Transwell and wound-healing experiments were adopted to detect cell proliferation, invasion and migration.

RESULTS

MiR-330-3p was under-expressed, while PRRX1 was highly expressed in the serum of patients, both of which had an area under the curve (AUC) of more than 0.9. MiR-330-3p and PRRX1 were associated with tumor diameter, TNM staging, lymph node metastasis and differentiation of GC patients. Overexpression of miR-330-3p and inhibition of PRRX1 expression could suppress epithelial-mesenchymal transition (EMT), proliferation, invasion and apoptosis of cells. What is more, WB assay showed that overexpressed miR-330-3p and inhibited PRRX1 could inhibit the expression levels of p-GSK-3β, β-catenin, cyclin D1, N-cadherin and vimentin proteins, while elevating GSK-3β, p-β-catenin and E-cadherin protein expressions. Dual-luciferase reporter assay confirmed that there was a targeting relation between miR-330-3p and PRRX1. Furthermore, rescue experiments revealed that the cell proliferation, invasion, migration did not differ significantly between co-transfected miR-330-3p-mimics+sh-PRRX1, miR-330-3p-inhibitor+si-PRRX1 groups of MKN45 and SGC7901 and the miR-NC group (without transfected sequences).

CONCLUSION

Overexpressed miR-330-3p can promote cell EMT, proliferation, invasion and apoptosis through inhibiting PRRX1-mediated Wnt/β-catenin signaling pathway, which is expected to be a potential therapeutic target for GC.