An overview of the multifaceted roles of miRNAs in gastric cancer: Spotlight on novel biomarkers and therapeutic targets

Potential of sonobiopsy as a novel diagnosis tool for brain cancer

Brain tumors have a poor prognosis. Early, accurate diagnosis and treatment are crucial. Although brain surgical biopsy can provide an accurate diagnosis, it is highly invasive and risky and is not suitable for follow-up examination. Blood-based liquid biopsies have a low detection rate of tumor biomarkers and limited evaluation ability due to the existence of the blood-brain barrier (BBB). The BBB is composed of brain capillary endothelial cells through tight junctions, which prevents the release of brain tumor markers to the human peripheral circulation, making it more difficult to diagnose, predict prognosis, and evaluate therapeutic response through brain tumor markers than other tumors. Focused ultrasound (FUS)-enabled liquid biopsy (sonobiopsy) is an emerging technique using FUS to promote the release of tumor markers into the circulatory system and cerebrospinal fluid, thus facilitating tumor detection. The feasibility and safety data from both animal models and clinical trials support sonobiopsy as a great potential in the diagnosis of brain diseases.

Catalytic hairpin assembly-assisted dual-signal amplification platform for ultrasensitive detection of tumor markers and intelligent diagnosis of gastric cancer

Quantification of extracellular tumor markers has shown great promise for non-invasive cancer diagnosis. Combined detection of multiple tumor markers instead of a single one is valuable for accurate diagnosis. Here, we integrate CRISPR-Cas12a with DNA catalytic hairpin assembly (CHA) to doubly amplify the output signal for detecting microRNA-182 (miR-182), which is overexpressed by gastric cancer patients. Additionally, we develop a CHA system with self-replicating capacity (SRCHA) to realize dual-signal amplification for the detection of carcinoembryonic antigen (CEA), a broad-spectrum tumor marker. The proposed cascade amplification strategies enable ultrasensitive detection of miR-182 and CEA with low LODs of 0.063 fM and 4.8 pg mL^-1, respectively. Moreover, we design a ternary "AND" logic gate using different concentrations of miR-182 and CEA as inputs, which demonstrates intelligent diagnosis of gastric cancer staging with a high accuracy of 93.3% in a clinical cohort of 30 individuals. Overall, our study expands the application of CRISPR-Cas12a in biosensing and provides a new diagnostic strategy for non-invasive liquid biopsy of gastric cancer before resorting to a traumatic tissue biopsy.

Histone Modifications and Non-Coding RNAs: Mutual Epigenetic Regulation and Role in Pathogenesis

In the last few years, more and more scientists have suggested and confirmed that epigenetic regulators are tightly connected and form a comprehensive network of regulatory pathways and feedback loops. This is particularly interesting for a better understanding of processes that occur in the development and progression of various diseases. Appearing on the preclinical stages of diseases, epigenetic aberrations may be prominent biomarkers. Being dynamic and reversible, epigenetic modifications could become targets for a novel option for therapy. Therefore, in this review, we are focusing on histone modifications and ncRNAs, their mutual regulation, role in cellular processes and potential clinical application.

Cord blood microRNA-376c and microRNA-1268a as biomarkers for neonatal hypoxic-ischaemic encephalopathy: a diagnostic accuracy study

Background

Hypoxic-ischaemic encephalopathy (HIE) is one of the most common causes of morbidity and mortality among neonates. There is a critical need for non-invasive novel biomarkers to detect HIE early, predict its outcomes and monitor its progression. We conducted this observational study to assess the relative expression of miRNA-376c and miRNA-1268a in cord blood as potential diagnostic and prognostic biomarkers for HIE.

Methods

A total of 100 neonates divided into two independent groups were included. The case group included 50 neonates with HIE, while the control group included 50 matched healthy neonates. Relative expressions of miRNA-376c and miRNA-1268a were measured in whole cord blood at birth using real-time PCR.

Results

Compared with the control group, patients with HIE had a significantly lower median level of miRNA-376c (0.168, IQR=0.011–0.411 vs 1, IQR=0.80–1.20) and a higher median level of miRNA-1268a (13.46, IQR=2.7–22.8 vs 1, IQR=0.4–1.6). Comparing neonates with HIE who survived versus those who did not survive, no statistically significant difference between the groups in terms of miRNA-376c and miRNA-1268a (p=0.124 and p=0.279) was elicited. Our diagnostic analysis showed that, at 0.90 points, miRNA-376c has a sensitivity and a specificity of 88% and 68.40%, with an area under the curve of 84%. At 2.70 points, miRNA-1268a has a sensitivity and a specificity of 76% and 100%, with an area under the curve of 96%.

Conclusion

The relative expression of miRNA-376c and miRNA-1268a was altered in the cord blood of neonates with HIE. In addition, they have moderate diagnostic accuracy in detecting HIE.

Methylation and Noncoding RNAs in Gastric Cancer: Everything Is Connected

Despite recent progress, gastric cancer remains one of the most common cancers and has a high mortality rate worldwide. Aberrant DNA methylation pattern and deregulation of noncoding RNA expression appear in the early stages of gastric cancer. Numerous investigations have confirmed their significant role in gastric cancer tumorigenesis and their high potential as diagnostic and prognostic biomarkers. Currently, it is clear that these epigenetic regulators do not work alone but interact with each other, generating a complex network. The aim of our review was to summarize the current knowledge of this interaction in gastric cancer and estimate its clinical potential for the diagnosis, prognosis, and treatment of the disease.

Effect of chitosan oligosaccharide-conjugated selenium on improving immune function and blocking gastric cancer growth

Selenium (Se) is a potential chemopreventive or chemotherapeutic agent against malignant tumor. Selenium-oligosaccharides are important selenium source of dietary supplementation. Due to the insufficient natural production, it is therefore urgent to develop selenium-oligosaccharides by artificial synthesis. Chitosan, the N-deacetylated derivative of chitin, has been applied widely in biomedical field, owing to its nontoxicity, hydrophilicity, biocompatibility, and biodegradation. While chitosan is water insoluble at neutral pH, limiting its application in physiological conditions. Chitosan oligosaccharide (COS), the hydrolysate of chitosan, is readily soluble in water because of the shorter chain lengths of the oligomers and the free amino groups in the D-glucosamine units. This study was aimed at preparing COS-conjugated selenium (COS-Se) and examining the toxicity and ability on improving immune function and blocking gastric cancer growth. Our results demonstrated that COS-Se displayed directly co-mitogenic and mitogenic actions on mouse splenocytes proliferation in vitro. Besides, COS-Se treatment could effectively elevate phagocytosis and increase the secretion of anti-inflammatory cytokine in mouse peritoneal macrophages. Further in vivo experiments showed that COS-Se exhibited immuno-enhancing effects through promoting the phagocytic index, spleen index and thymus index with no obvious toxicity to Kunming mice. Moreover, COS-Se inhibited proliferation and metastasis of human gastric cancer cells, with non-toxic effects on the normal fibroblast cells in vitro. COS-Se supplementation could significantly repress the growth of gastric adenocarcinoma through reducing levels of CD34, vascular endothelial growth factor and matrix metalloproteinase-9 of nude mice. In conclusion, COS-Se was non-toxic and showed great potential as a functional food ingredient in cancer prevention.

The Aberrant Expression of MicroRNA-125a-5p/IGF2BP3 Axis in Advanced Gastric Cancer and Its Clinical Relevance

RNA-binding proteins have been associated with cancer development. The overexpression of a well-known RNA-binding protein, insulin-like growth factor 2 messenger RNA-binding protein 3, has been identified as an indicator of poor prognosis in patients with various types of cancer. Although gastric cancer is a relatively frequent and potentially fatal malignancy, the mechanism by which insulin-like growth factor 2 messenger RNA-binding protein 3 regulates the development of this cancer remains unclear. This study aimed to investigate the role and regulatory mechanism of insulin-like growth factor 2 messenger RNA-binding protein 3 in gastric cancer. An analysis of IGF2BP3 expression patterns reported in 4 public gastric cancer-related microarray data sets from the Gene Expression Omnibus and The Cancer Genome Atlas-Stomach Adenocarcinoma revealed strong expression of this gene in gastric cancer tissues. Insulin-like growth factor 2 messenger RNA-binding protein 3 expression in gastric cancer was further confirmed via quantitative reverse transcription polymerase chain reaction and immunohistochemistry, respectively, in an in-house gastric cancer cohort (n = 30), and the association of insulin-like growth factor 2 messenger RNA-binding protein 3 expression with clinical parameters and prognosis was analyzed. Notably, stronger IGF2BP3 expression significantly correlated with poor prognosis, and significant changes in insulin-like growth factor 2 messenger RNA-binding protein 3 expression were only confirmed in patients with advanced-stage gastric cancer in an independent cohort. The effects of insulin-like growth factor 2 messenger RNA-binding protein 3 on cell proliferation were confirmed through in vitro experiments involving the HGC-27 gastric cancer cell line. MicroR-125a-5p, a candidate microRNA that target on insulin-like growth factor 2 messenger RNA-binding protein 3, decreased in advanced-stage gastric cancer. Upregulation of microR-125a-5p inhibited insulin-like growth factor 2 messenger RNA-binding protein 3, and dual-luciferase report assay indicated that microR-125a-5p inhibited the translation of IGF2BP3 by directly targeting the 3' untranslated region. These results indicate that the microR-125a-5p/insulin-like growth factor 2 messenger RNA-binding protein 3 axis contributes to the oncogenesis of advanced gastric cancer.

MiR-17-5p promotes cellular proliferation and invasiveness by targeting RUNX3 in gastric cancer

BACKGROUND

Dysregulated microRNAs (miRNAs/miRs) directly modulate the biological functions of gastric cancer (GC) cells and contribute to the initiation and progression of GC. MiR-17-5p and runt-related transcription factor 3 (RUNX3) have been reported to be related to GC progression; however, the specific interaction between miR-17-5p and RUNX3 in GC require further investigation.

METHODS

Western blotting, real-time PCR and immunohistochemistry were used to study the expression level of miR-17-5p and RUNX3 in gastric cancer tissues and plasma. The biological function of miR-17-5p was examined by measuring cell proliferation, apoptosis and cell invasion in vitro; the target gene of miR17-5p was identified by luciferase reporter assays, RNA Binding protein immunoprecipitation (RIP) and western blotting. In vivo animal study was conducted to confirm the role of miR-17-5p during tumorigensis of gastric cancer.

RESULTS

This study showed that miR17-5p was upregulated in the plasma and tissues of patients with GC, while RUNX3 was downregulated in GC tissues. Functional experiments indicated that miR-17-5p mimics promoted the proliferation and invasion of GC via suppressing apoptosis in vitro. Furthermore, bioinformatics prediction, luciferase reporter assays, reverse transcription quantitative polymerase chain reaction assays, RIP and western blotting analysis demonstrated that RUNX3 was a direct target gene of miR-17-5p in GC. In addition, overexpression of RUNX3 suppressed the proliferation and invasiveness of GC cells. In vivo data indicated miR-17-5p agomir significantly promoted tumor growth. In contrast, miR-17-5p antagomir notably decreased tumor volume compared with control group.

CONCLUSIONS

MiR-17-5p promoted the progression of GC via directly targeting RUNX3, suggesting that miR-17-5p and RUNX3 could be considered as diagnostic and therapeutic targets for patients with GC.

Exosomes-microRNAs interacted with gastric cancer and its microenvironment: a mini literature review

Exosomes have appeared as fundamental vehicle-modulated crosstalk among various cells in the tumor microenvironment. The systematic understanding of exosomes in gastric cancer (GC) enhances our comprehension about the tumor growth, metastasis, chemoresistance and diagnosis of cancers. The versatile functions of exosomes provide reasonable explanations about the propensity for GC metastasis. The selectively enriched components, especially some exosomal miRNAs, are potential noninvasive biomarkers for sensitive and specific GC diagnosis. Given the characteristics of exosomes, frontier researchers are stimulated to modulate the biogenesis, concentrations or release of exosomes so as to disturb malignant signals between cells. Abnormal expression profiles of exosomal miRNAs afford potential GC therapeutic or diagnostic strategies in future.

Efficient delivery of anti-miR-210 using Tachyplesin, a cell penetrating peptide, for glioblastoma treatment

The levels of microRNAs (miRNAs) are altered in various diseases including glioblastoma (GBM) and this alteration may have widespread effects on various hallmarks of cancer cells. MiR210 is overexpressed in GBM and functions as an oncogenic miRNA. Anti-miR210 therapy holds great promise but its efficient delivery remains a major challenge. Our work here explores a novel role of Tachyplesin (Tpl), a cell-penetrating antimicrobial peptide, as a nanocarrier for anti-miR210. Tpl electrostatically interacts with anti-miR210 at 1:25 and 1:50 (anti-miR:Tpl) weight ratios to form a complex and efficiently delivers anti-miR210 inside GBM cells cultured as 2D and 3D spheroid model. Treatment of GBM cells with the complex significantly inhibited miR210 levels (~90%), proliferation, migration and spheroid formation ability and induced apoptosis as evident by increased levels of caspase 3/7 and ROS. GBM cells pre-treated with anti-miR210:Tpl complex were also found to be sensitive to TMZ mediated action. Uptake of the complex in GBM cells induced the levels of miR210 targeted tumor suppressor genes, NeuroD2 and HIF3A. Overall, our work reveals a novel and efficient miRNA delivery ability of Tpl in glioma cells, holding a great promise for treatment of GBM and potentially for other cancers.

Long noncoding RNA SNHG16 silencing inhibits the aggressiveness of gastric cancer via upregulation of microRNA-628-3p and consequent decrease of NRP1

Background

MicroRNA-628-3p (miR-628) has been reported to play important roles in the progression of multiple human cancer types. Nonetheless, whether the expression profile of miR-628 is altered in gastric cancer remains unclear and whether its aberrant expression plays a crucial part in the aggressiveness of gastric cancer is yet to be determined. Therefore, in this study, we systematically investigated the involvement of miR-628 in gastric cancer progression.

Materials and methods

MiR-628 expression in gastric cancer tissues and cell lines were determined via reverse transcription-quantitative polymerase chain reaction (RT-qPCR). A CCK-8 assay, flow-cytometric analysis, Transwell assays, and a xenograft model experiment were performed to evaluate the influence of miR-628 overexpression on gastric cancer cells. Notably, the mechanisms underlying the tumor-suppressive activity of miR-628 in gastric cancer cells were explored by bioinformatics analysis, a luciferase reporter assay, RT-qPCR, and Western blotting.

Results

MiR-628 expression was low in gastric cancer tissue samples and cell lines. The low expression of miR-628 was closely associated with the lymph node metastasis, invasive depth and TNM stage among patients with gastric cancer. Further clinical analysis indicated that patients with gastric cancer underexpressing miR-628 had a worse prognosis than did the patients with high miR-628 expression in the tumor. Overexpressed miR-628 restrained proliferation, migration, and invasion; induced apoptosis; and impaired tumor growth of gastric cancer cells. In addition, neuropilin 1 (NRP1) mRNA was validated as the direct target of miR-628 in gastric cancer. Long noncoding RNA small nucleolar RNA host gene 16 (SNHG16) was demonstrated to sponge miR-628 in gastric cancer. Moreover, miR-628 knockdown abrogated the influence of SNHG16 silencing on gastric cancer cells.

Conclusion

Our findings elucidate how the SNHG16–miR-628–NRP1 pathway serves as a regulatory network playing crucial roles in gastric cancer progression, suggesting that this pathway may be a novel target of anticancer therapy.