MicroRNA - Volume 11, Issue 1, 2022

It is estimated that 2-4% of live births will have a birth defect (BD). The availability of biomarkers for the prenatal detection of BDs will facilitate early risk assessment, prompt medical intervention and ameliorating disease severity. miRNA expression levels are often found to be altered in many diseases. There is, thus, a growing interest in determining whether miRNAs, particularly extracellular miRNAs, can predict, diagnose, or monitor BDs. These miRNAs, typically encapsulated in exosomes, are released by cells (including those of the fetus and placenta) into the extracellular milieu, such as blood, urine, saliva and cerebrospinal fluid, thereby enabling interaction with target cells. Exosomal miRNAs are stable, protected from degradation, and retain functionality. The observation that placental and fetal miRNAs can be detected in maternal serum, provides a strong rationale for adopting miRNAs as noninvasive prenatal biomarkers for BDs. In this mini-review, we examine the current state of research involving the use of miRNAs as prognostic and diagnostic biomarkers for BD.

Gastric cancer (GC) is the fourth most frequent disease in the world and the second cause of cancer-related death. In this way, over 80% of diagnoses are made in the middle to advanced degrees of the disease, underscoring the requirement for innovative biomarkers that can be identified quickly. Meaningly, biomarkers that can complement endoscopic diagnosis and be used to detect patients with a high risk of GC are desperately needed. These biomarkers will allow for the accurate prediction of therapy response and prognosis in GC patients, as well as the development of an optimal treatment strategy for each individual. Conspicuously, microRNAs (miRNAs) and small noncoding RNA regulate the expression of target mRNA, thereby modifying critical biological mechanisms. According to the data, abnormally miRNAs expression in GC is linked to tumor growth, carcinogenesis, aggression, and distant metastasis. Importantly, miRNA expression patterns and nextgeneration sequencing (NGS) can also be applied to analyze different kinds of tissues and cancers. Given the high death rates and poor prognosis of GC, and the absence of a clinical diagnostic factor that is adequately sensitive to GC, research on novel sensitive and specific markers for GC diagnosis is critical. In this review, we examine the latest research findings that suggest the feasibility and clinical utility of miRNAs in GC.

Background: The analysis of individual microRNAs (miRNAs) as a diagnostic and prognostic tool for the effective treatment of various diseases has aroused particular interest in the scientific community. The determination of circulating miRNAs makes it possible to assess biological changes associated with nutritional processes, the intake of dietary supplements and drugs, etc. The profile of circulating miRNAs reflects the individual adaptation of the organism to the effect of specific environmental conditions. Objective: The objective of this study is to systematize the data and show the importance of circulating miRNAs as new potential biomarkers of the organism's response to the intake of various dietary supplements, drugs, and consider the possibility of their use in doping control. Methods: A systematic analysis of scientific publications (ncbi.nlm.nih.gov) on the miRNA expression profile in response to the intake of dietary supplements and drugs most often used by athletes, and supposed their role as potential markers in modern doping control was carried out. Results: The profile of circulating miRNAs is highly dependent on the intake of a particular drug, and, therefore, may be used as a marker of the effects of biologically active supplements and drugs including the substances from the Prohibited List of the World Anti-Doping Agency (WADA). Conclusion: Monitoring of circulating miRNAs can serve as a high-precision marker for detecting doping abuse in elite sports. However, it is necessary to conduct additional studies on the effect of complex drugs on the profile of circulating miRNAs and individual circulating miRNAs on a particular biological process.

Introduction: DEAD-box RNA helicases catalyze the ATP-dependent unwinding of doublestranded RNA. In addition, they are required for protein displacement and remodelling of RNA or RNA/protein complexes. P68 RNA helicase regulates the alternative splicing of the important protooncogene H-Ras, and numerous studies have shown that p68 RNA helicase is probably involved in miRNA biogenesis, mainly through Drosha and RISC/DICER complexes. Objective: This study aimed to determine how p68 RNA helicase affects the activity of selected mature miRNAs, including miR-342, miR-330, miR-138 and miR-206, miR-126, and miR-335, and let-7a, which are known to be related to cancer processes. Methods: The miRNA levels were analyzed in stable HeLa cells containing p68 RNA helicase RNAi induced by doxycycline (DOX). Relevant results were repeated using transient transfection with pSuper/ pSuper-p68 RNA helicase RNAi to avoid DOX interference. Results: Herein, we reported that p68 RNA helicase downregulation increases the accumulation of the mature miRNAs, such as miR-126, let-7a, miR-206, and miR-138. Interestingly, the accumulation of these mature miRNAs does not downregulate their known protein targets, thus suggesting that p68 RNA helicase is required for mature miRNA-active RISC complex activity. Conclusion: Furthermore, we demonstrated that this requirement is conserved, as drosophila p68 RNA helicase can complete the p68 RNA helicase depleted activity in human cells. Dicer and Drosha proteins are not affected by the downregulation of p68 RNA helicase despite the fact that Dicer is also localized in the nucleus when p68 RNA helicase activity is reduced.

Background: Since ancient times, "betel leaf" (Piper betle) has been revered for its religious, cultural, and medicinal properties. Phytochemicals from the Piper betle are effective in a variety of conditions, including cancer. To date, however, no genomic study or evidence has been found to elucidate the regulatory mechanism that underpins its therapeutic properties. This is the first study of its kind to predict Piper betle miRNAs and also the first genomics source representation of Piper betle. According to previous research, miRNAs from the plants we eat can regulate gene expression. In line with this, our in-silico study revealed that Piper betle and human cross-kingdom control occurs. Methods: This study demonstrates the prediction and in-silico validation of Piper betle miRNAs from NGS-derived transcript sequences. The cross-kingdom regulation, which can also be understood as inter- species RNA regulation, was studied to identify human mRNA targets controlled by Piper betle miRNAs. Functional annotation and gene-disease association of human targets were performed to understand the role of Piper betle miRNAs in human health and disease. The protein-protein interaction and expression study of targets was further carried out to decipher their role in cancer development. Results: Identified six Piper betle miRNAs belonging to miR156, miR164, miR172, and miR535 families were discovered to target 198 human mRNAs involved in various metabolic and disease processes. Angiogenesis and the cell surface signaling pathway were the most enriched gene ontology correlated with targets, both of which play a critical role in disease mechanisms, especially in the case of carcinoma. In an analysis of gene-disease interactions, 40 genes were found to be related to cancer. According to a protein-protein interaction, the CDK6 gene, which is thought to be a central regulator of cell cycle progression, was found as a hub protein, affecting the roles of CBFB, SAMD9, MDM4, AXIN2, and NOTCH2 oncogenes. Further investigation revealed that pbe-miRNA164a can be used as a regulator to minimise disease severity in Acute Myeloid Leukemia, where CDK6 expression is highest compared to normal cells. Conclusion: The predicted pbe-miRNA164a in this study can be a promising suppressor of CDK6 gene involved in tumour angiogenesis. In vivo validation of the pbe-miRNA164a mimic could pave the way for new opportunities to fight cancer and leverage the potential of Piper betle in the healthcare sector.

Background: Small non-coding micro RNAs (miRNAs) are indicated in various metabolic processes and play a critical role in disease pathology, including gestational diabetes mellitus (GDM). Objective: The purpose of this study was to examine the altered expression of miRNAs and their target genes in placental tissue (PL), cord blood (CB), and maternal blood (MB) of matched non-glucose tolerant (NGT) and GDM mother. Methods: In a case-control study, micro-RNA was quantified from forty-five serum (MB n = 15, CB n = 15, and PL n = 15) and matched placental tissue using stem-loop RT-qPCR followed by target prediction, network construction and functional and pathways enrichment analysis. Further, target genes were verified in-vitro through transfection and RT-qPCR. Results: Five miRNAs, namely hsa-let 7a-5P, hsa-miR7-5P, hsa-miR9-5P, hsa-miR18a-5P, and hsamiR23a- 3P were significantly over-expressed (p < 0.05) in all three samples namely PL, CB, and MB of GDM patients. However, the sample-wise comparison reveals higher expression of miRNA 7 in MB while lowest in CB than control. Furthermore, a comparison of fold change expression of target genes discloses a lower expression of IRS1, IRS2, and RAF1 in MB while comparatively higher expression of NRAS in MB and CB. In-vitro validation reveals lower expression of IRS1/2 and RAF1 in response to overexpression of miR-7 and vice-versa. Thus it is evident that increased miRNA7 expression causes down-regulation of its target genes IRS1, IRS2, and RAF1 in GDM mother compared to control. Further, target prediction, pathway enrichment, and hormone analysis (significantly higher FSH & LH in MB of GDM compared to NGT) revealed insulin signaling, inflammatory and GnRH signaling as major pathways regulated by miRNA7. Conclusion: Thus, an elevated level of miRNA7 may be associated with the progression of GDM by altering the multiple pathways like insulin, GnRH, and inflammatory signaling pathways via targeting IRS1, IRS2, and RAF1, implicating a new therapeutic target for GDM.

Background: Papillary thyroid cancer (PTC) is the most frequent subtype of thyroid carcinoma, mainly detected in patients with benign thyroid nodules (BTN). Due to the invasiveness of accurate diagnostic tests, there is a need to discover applicable biomarkers for PTC. So, in this study, we aimed to identify the genes associated with prognosis in PTC. Besides, we performed a machine learning tool to develop a non-invasive diagnostic approach for PTC. Methods: For the study purposes, the miRNA dataset GSE130512 was downloaded from the GEO database and then analyzed to identify the common differentially expressed miRNAs in patients with non-metastatic PTC (nm-PTC)/metastatic PTC (m-PTC) compared with BTNs. The SVM was also applied to differentiate patients with PTC from those patients with BTN using the common DEMs. A protein-protein interaction network was also constructed based on the targets of the common DEMs. Next, functional analysis was performed, the hub genes were determined, and survival analysis was then executed. Results: A total of three common miRNAs were found to be differentially expressed among patients with nm-PTC/m-PTC compared with BTNs. In addition, it was established that the autophagosome maturation, ciliary basal body-plasma membrane docking, antigen processing as ubiquitination & proteasome degradation, and class I MHC mediated antigen processing & presentation are associated with the pathogenesis of PTC. Furthermore, it was illustrated that RPS6KB1, CCNT1, SP1, and CHD4 might serve as new potential biomarkers for PTC prognosis. Conclusion: RPS6KB1, CCNT1, SP1, and CHD4 may be considered new potential biomarkers used for prognostic aims in PTC. However, performing validation tests is inevitable in the future.