Relationship between miR-21 and miR-182 levels in peripheral blood and gastric cancer tissue

MicroRNA-183 cluster: a promising biomarker and therapeutic target in gastrointestinal malignancies

Small non-coding RNAs (microRNA, miR), powerful epigenetic regulators, were found involved in the regulation of most biological functions via post-translational inhibition of protein expression. Increased expression of pro-oncogenic miRs (known as miR cancer biomarkers) and inhibition of pro-apoptotic miR expression have been demonstrated in different tumors. The recently identified miR-183 was found implicated in gastrointestinal tumor metabolism regulation. Elevated miR-183 expression and cancer-promoting effects were reported in esophageal and colorectal cancers, which was partially contradicted by controversial data observed in gastric cancers. Anti-cancer effect of miR-183 in gastric cancer cells was associated with the Bim-1 and Ezrin genes regulation. Many studies indicated that miR-183 can inhibit tumor suppressor genes in most cell lines, promoting tumor cell proliferation and migration. Increased miR-183 level results in the downregulation of FOXO1, PDCD4, and other tumor suppressor genes in gastrointestinal tumor cells. MiR-183 also influences the signaling of PI3K/AKT/mTOR, Wnt/β-catenin, and Bcl-2/p53 signaling pathways. Mir-183 inhibits apoptosis and autophagy, and promotes epithelial-to-mesenchymal transition, cancer cell proliferation, and migration. Accordingly, gastrointestinal cancer occurrence, development of chemoradiotherapy resistance, recurrence/metastasis, and prognosis were associated with miR-183 expression. The current study assessed reported miR-183 functions and signaling, providing new insights for the diagnosis and treatment of gastrointestinal malignancies.

Drug-Like Small Molecules That Inhibit Expression of the Oncogenic MicroRNA-21

We report the discovery of drug-like small molecules that bind specifically to the precursor of the oncogenic and pro-inflammatory microRNA-21 with mid-nanomolar affinity. The small molecules target a local structure at the Dicer cleavage site and induce distinctive structural changes in the RNA, which correlate with specific inhibition of miRNA processing. Structurally conservative single nucleotide substitutions eliminate the conformational change induced by the small molecules, which is also not observed in other miRNA precursors. The most potent of these compounds reduces cellular proliferation and miR-21 levels in cancer cell lines without inhibiting kinases or classical receptors, while closely related compounds without this specific binding activity are inactive in cells. These molecules are highly ligand-efficient (MW < 330) and display specific biochemical and cellular activity by suppressing the maturation of miR-21, thereby providing an avenue toward therapeutic development in multiple diseases where miR-21 is abnormally expressed.

Pre-clinical and clinical importance of miR-21 in human cancers: Tumorigenesis, therapy response, delivery approaches and targeting agents

The field of non-coding RNA (ncRNA) has made significant progress in understanding the pathogenesis of diseases and has broadened our knowledge towards their targeting, especially in cancer therapy. ncRNAs are a large family of RNAs with microRNAs (miRNAs) being one kind of endogenous RNA which lack encoded proteins. By now, miRNAs have been well-coined in pathogenesis and development of cancer. The current review focuses on the role of miR-21 in cancers and its association with tumor progression. miR-21 has both oncogenic and onco-suppressor functions and most of the experiments are in agreement with the tumor-promoting function of this miRNA. miR-21 primarily decreases PTEN expression to induce PI3K/Akt signaling in cancer progression. Overexpression of miR-21 inhibits apoptosis and is vital for inducing pro-survival autophagy. miR-21 is vital for metabolic reprogramming and can induce glycolysis to enhance tumor progression. miR-21 stimulates EMT mechanisms and increases expression of MMP-2 and MMP-9 thereby elevating tumor metastasis. miR-21 is a target of anti-cancer agents such as curcumin and curcumol and its down-regulation impairs tumor progression. Upregulation of miR-21 results in cancer resistance to chemotherapy and radiotherapy. Increasing evidence has revealed the role of miR-21 as a biomarker as it is present in both the serum and exosomes making them beneficial biomarkers for non-invasive diagnosis of cancer.

Effect of artificial skin membrane on the expression of miR-155 and miR-506-3p in patients with second-degree burns

OBJECTIVE

To investigate the effect of artificial skin on the expression of miR-155 and miR-506-3p in patients with second-degree burns.

METHODS

The study subjects included 50 patients with second-degree burns treated from July 2019 to July 2021. The control group received routine nursing, while the research group received both routine and artificial skin intervention simultaneously. The changes in wound tissue fibrosis and prognosis were observed. The expression levels of miR-155 and miR-506-3p and their downstream regulatory factors were detected and correlated with the rehabilitation of patients after artificial skin treatment.

RESULTS

After treating second-degree burns with artificial skin membranes, the patient's wound tissue fibrosis and inflammation level improved. At the same time, the expression levels of miR-155 and miR-506-3p in related tests were higher than those in patients with available treatment.

CONCLUSION

The effect of artificial skin membrane on the wound healing of second-degree burn patients may be realized by influencing the expression levels of miR-155 and miR-506-3p and their related signaling pathways.

MicroRNA-182 is a potential biomarker for prognosis of gastric cancer: A protocol for meta-analysis and bioinformatics analysis

BACKGROUND

Being the second leading cause of cancer death in the world, gastric cancer is a common malignant tumor in digestive system. Most patients were diagnosed in advanced stage and had poor prognosis. In recent years, related studies have displayed that MicroRNA-182 (miRNA-182) can promote the proliferation, infiltration, metastasis and drug resistance of tumor cells, so it can be used as a new molecular marker for the early diagnosis, prognosis, and treatment of tumors. However, the expression and prognosis of miRNA-182 in gastric cancer are not clear. Therefore, this study conducted a meta-analysis to further clarify the relationship between the expression of miRNA-182 in gastric cancer and prognosis. In addition, a bioinformatics analysis was adopted to further analyze the possible molecular mechanism of miRNA-182, so as to provide a theoretical basis for the diagnosis, treatment, and prognosis of patients suffering from gastric cancer.

METHODS

The following electronic databases were searched on computer: Wanfang, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure, the Chongqing VIP Chinese Science and Technology Periodical Database, PubMed, Embase, and Web of Science databases. The retrieval time is set to build the database until April 2021. Combined hazard ratios (HRs) and 95% confidence intervals (95% CIs) were used to evaluate the effects of miRNA-182 on the prognosis of gastric cancer. Stata 16.0 software was applied for the meta-analysis. The expression of miRNA-182 in gastric cancer was analyzed by Gene Expression Omnibus database and The Cancer Genome Atlas database. The survival curve of miRNA-182 differential expression was analyzed by OncomiR. The target genes of miRNA-182 were predicted by TargetScan, miRBase, miRTarBase, starBase V2.0, and miRWalk. The target genes were obtained by the intersection of Wayne diagram. DAVID database was used for gene ontology (GO) and Kyoto encyclopedia of genes and genomes enrichment analysis. STRING database and Cytoscape were applied to construct Protein-protein interaction network to obtain key genes (hub gene). The expression of hub gene in gastric cancer was analyzed by gene expression profiling interactive analysis. The survival curve between hub gene and prognosis of gastric cancer was drawn by Kaplan-Meier Plotter database. TIMER database was used to analyze the relationship between hub gene expression and immune cell infiltration in gastric cancer.

RESULTS

The results of this meta-analysis will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This study provides high-quality evidence support for the expression of miRNA-182 and the prognosis of gastric cancer. Through bioinformatics analysis, we further discussed the mechanism of miRNA-182 in gastric cancer and the understanding of related pathways.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/EHJ6X.

Circ_002059 suppresses cell proliferation and migration of gastric cancer via miR-182/MTSS1 axis

Circular RNAs (circRNAs) play either oncogenic or tumor suppressive roles in gastric cancer (GC). A previous study demonstrated that circ_002059, a typical circRNA, was downregulated in GC tissues. However, the role and mechanism of circ_002059 in GC development are still unknown. In this study, the levels of circ_002059, miR-182, and metastasis suppressor-1 (MTSS1) were examined by real-time quantitative polymerase chain reaction and western blot analysis. Cell proliferation and migration were evaluated by MTT assay and Transwell migration assay, respectively. The interactions between miR-182 and circ_002059 or MTSS1 were analyzed by dual-luciferase reporter assay. A GC xenograft model was established to validate the role of circ_002059 in GC progression in vivo. Overexpression of circ_002059 significantly inhibited, whereas knockdown of circ_002059 notably facilitated, cell proliferation and migration in GC cells. MTSS1 was found to be a direct target of miR-182 and circ_002059 upregulated MTSS1 expression by competitively sponging miR-182. Transfection with miR-182 mimic and MTSS1 silencing abated the inhibitory effect of circ_002059 on GC progression. Circ_002059 inhibited GC cell xenograft tumor growth by regulating miR-182 and MTSS1 expression. Collectively, Circ_002059 inhibited GC cell proliferation and migration in vitro and xenograft tumor growth in mice, by regulating the miR-182/MTSS1 axis.

Exosomal miR-21/Let-7a ratio distinguishes non-small cell lung cancer from benign pulmonary diseases

Aim

To assess the exosomal miR‐21/Let‐7a ratio, a noninvasive method, in distinguishing non‐small cell lung cancer (NSCLC) from benign pulmonary diseases.

Methods

The exosomes were extracted from the peripheral blood serum using serum exosomal extraction kit. miR‐21 and Let‐7a levels were evaluated by quantitative reverse transcription polymerase chain reaction.

Results

We found that miR‐21/Let‐7a ratio of NSCLC patients was significantly higher than that of healthy people, patients with pulmonary inflammation diseases, and benign pulmonary nodules, respectively. Receiver‐operating characteristic analysis revealed that as compared with healthy controls, miR‐21/Let‐7a produced the area under the curve (AUC) at 0.8029 in patients with NSCLC, which helped to distinguish NSCLC from healthy controls with 81.33% sensitivity and 69.57% specificity. In addition, the AUC of miR‐21/Let‐7a in NSCLC patients was 0.8196 in comparison to patients with pulmonary inflammation diseases. Meanwhile, the sensitivity and specificity were 56.00% and 100%, respectively. Furthermore, compared with patients with benign pulmonary nodules, the AUC of miR‐21/Let‐7a in NSCLC patients was 0.7539. The sensitivity and specificity were 56.00% and 82.61%, respectively.

Conclusion

In the present study, our findings revealed that exosomal miR‐21/Let‐7a ratio holds considerable promise as a noninvasive biomarker for the diagnosis of NSCLC from benign pulmonary diseases.