Regulation and function of miRNA-21 in health and disease

NAFLD and Vitamin D: Evidence for Intersection of MicroRNA Regulated Pathways

Non-alcoholic fatty liver disease (NAFLD) is now the most common cause of chronic liver disease, worldwide. The molecular pathogenesis of NAFLD is complex, involving numerous signalling molecules including microRNAs (miRNAs). Dysregulation of miRNA expression is associated with hepatic inflammation, fibrosis and hepatocellular carcinoma. Although miRNAs are also critical to the cellular response to vitamin D, mediating regulation of the vitamin D receptor (VDR) and vitamin D’s anticancer effects, a role for vitamin D regulated miRNAs in NAFLD pathogenesis has been relatively unexplored. Therefore, this review aimed to critically assess the evidence for a potential subset of miRNAs that are both dysregulated in NAFLD and modulated by vitamin D. Comprehensive review of 89 human studies identified 25 miRNAs found dysregulated in more than one NAFLD study. In contrast, only 17 studies, including a protocol for a trial in NAFLD, had examined miRNAs in relation to vitamin D status, response to supplementation, or vitamin D in the context of the liver. This paper summarises these data and reviews the biological roles of six miRNAs (miR-21, miR-30, miR-34, miR-122, miR-146, miR-200) found dysregulated in multiple independent NAFLD studies. While modulation of miRNAs by vitamin D has been understudied, integrating the data suggests seven vitamin D modulated miRNAs (miR-27, miR-125, miR-155, miR-192, miR-223, miR-375, miR-378) potentially relevant to NAFLD pathogenesis. Our summary tables provide a significant resource to underpin future hypothesis-driven research, and we conclude that the measurement of serum and hepatic miRNAs in response to vitamin D supplementation in larger trials is warranted.

Circular Antisense Oligonucleotides for Specific RNase-H-Mediated microRNA Inhibition with Reduced Off-Target Effects and Nonspecific Immunostimulation

Antisense microRNA oligodeoxynucleotides (AMOs) are powerful tools to regulate microRNA functions. Unfortunately, severe off-target effects are sometimes observed. Due to the special topological and enzymatic properties of circular oligodeoxynucleotides (c-ODNs), we rationally designed and developed circular AMOs, which effectively inhibited microRNA functions with high target specificity and low off-target effects. Binding and enzymatic assays indicated that small circular AMOs could selectively bind to and further digest the target mature miR 21, which suggested that the topological properties of circular c-ODNs significantly decreased their off-target effects as microRNA inhibitors. Compared with their linear corresponding phosphorothioated AMOs, circular phosphorothioated AMOs could more effectively reduce the amount of carcinogenic miR 21 and miR 222 and upregulate the expression levels of downstream antitumor proteins of PTEN and PDCD4. In addition, c-PS-antimiRs induced much less nonspecific immunostimulatory effects compared with their linear partner PS-ODNs, further indicating the advantages of circular ODNs in nonspecific immunostimulation.

Biological Roles and Clinical Significance of Exosome-Derived Noncoding RNAs in Bladder Cancer

Bladder cancer (BCa) is a common heterogeneous urinary system tumor with high malignancy and limited advancement in treatment. Limited understanding of BCa has not contributed to any significant progress in diagnosis or treatment, exploring the mechanisms underlying BCa has become an urgent research focus. Exosomes, a type of extracellular vesicle (EV), have drawn substantial interest for their important roles in mediating intracellular communication. Exosomes shuttle numerous bioactive molecules, and noncoding RNAs (ncRNAs) are among the most numerous. ncRNAs including microRNA, long noncoding RNA, and circular RNA are sorted and packaged into exosomes selectively and transferred into recipient cells to regulate their function. Exosomal ncRNAs are associated with hallmarks of BCa, such as proliferation, apoptosis, epithelial-mesenchymal transition (EMT), cell cycle arrest, lymphangiogenesis, and chemotherapy resistance. Exosomal ncRNAs can also be detected in urine and serum, making them encouraging biomarkers for BCa diagnosis and prognosis. More importantly, exosomes exhibit excellent biocompatibility and potential for diversified applications. The delivery of bioactive substances and drugs into specific cells has become a promising approach for precision therapy for BCa patients. In addition, cancer vaccines have also received increasing attention. In this review, we summarize the current research on the regulatory roles of exosomal ncRNAs in BCa tumorigenesis and progression, as well as their potential clinical value in accelerating the diagnosis and therapy of BCa.

Cardiorenal Syndrome: New Pathways and Novel Biomarkers

Cardiorenal syndrome (CRS) is a multi-organ disease characterized by the complex interaction between heart and kidney during acute or chronic injury. The pathogenesis of CRS involves metabolic, hemodynamic, neurohormonal, and inflammatory mechanisms, and atherosclerotic degeneration. In the process of better understanding the bi-directional pathophysiological aspects of CRS, the need to find precise and easy-to-use markers has also evolved. Based on the new pathophysiological standpoints and an overall vision of the CRS, the literature on renal, cardiac, metabolic, oxidative, and vascular circulating biomarkers was evaluated. Though the effectiveness of different extensively applied biomarkers remains controversial, evidence for several indicators, particularly when combined, has increased in recent years. From new aspects of classic biomarkers to microRNAs, this review aimed at a 360-degree analysis of the pathways that balance the kidney and the heart physiologies. In this delicate system, different markers and their combination can shed light on the diagnosis, risk, and prognosis of CRS.

Crosstalk Between microRNAs and the Pathological Features of Secondary Lymphedema

Secondary lymphedema is characterized by lymphatic fluid retention and subsequent tissue swelling in one or both limbs that can lead to decreased quality of life. It often arises after loss, obstruction, or blockage of lymphatic vessels due to multifactorial modalities, such as lymphatic insults after surgery, immune system dysfunction, deposition of fat that compresses the lymphatic capillaries, fibrosis, and inflammation. Although secondary lymphedema is often associated with breast cancer, the condition can occur in patients with any type of cancer that requires lymphadenectomy such as gynecological, genitourinary, or head and neck cancers. MicroRNAs demonstrate pivotal roles in regulating gene expression in biological processes such as lymphangiogenesis, angiogenesis, modulation of the immune system, and oxidative stress. MicroRNA profiling has led to the discovery of the molecular mechanisms involved in the pathophysiology of auto-immune, inflammation-related, and metabolic diseases. Although the role of microRNAs in regulating secondary lymphedema is yet to be elucidated, the crosstalk between microRNAs and molecular factors involved in the pathological features of lymphedema, such as skin fibrosis, inflammation, immune dysregulation, and aberrant lipid metabolism have been demonstrated in several studies. MicroRNAs have the potential to serve as biomarkers for diseases and elucidation of their roles in lymphedema can provide a better understanding or new insights of the mechanisms underlying this debilitating condition.

Label-free and sensitive MiRNA detection based on turn-on fluorescence of DNA-templated silver nanoclusters coupled with duplex-specific nuclease-assisted signal amplification

A novel strategy for microRNAs (miRNAs) detection has been developed utilizing duplex-specific nuclease-assisted signal amplification (DSNSA) and guanine-rich DNA-enhanced fluorescence of DNA-templated silver nanoclusters (AgNCs). The combination between target miRNA, DSNSA, and AgNCs is achieved by the unique design of DNA sequences. Target miRNA opens the hairpin structure of the Hairpin DNA probe (HP) by hybridizing with the HP and initiates the duplex-specific nuclease-assisted signal amplification (DSNSA) reaction. The DSNSA reaction generates the release of the guanine-rich DNA sequence, which can turn on the fluorescence of the dark AgNCs by hybridizing with the DNA template of the dark AgNCs. The fluorescence intensity of AgNCs corresponds to the dosage of the target miRNA. This is measured at 630 nm by exciting at 560 nm. The constructed method exhibits a low detection limit (~8.3 fmol), a great dynamic range of more than three orders of magnitude, and excellent selectivity. Moreover, it has a good performance for miR-21 detection in complex biological samples. A novel strategy for microRNAs (miRNAs) detection has been developed utilizing duplex-specific nuclease-assisted signal amplification (DSNSA) and guanine-rich DNA-enhanced fluorescence of DNA-templated silver nanoclusters (AgNCs).

Downregulation of microRNA-21 contributes to decreased collagen expression in venous malformations via transforming growth factor-β/Smad3/microRNA-21 signaling feedback loop

OBJECTIVE

Venous malformations (VMs) are the most frequent vascular malformations and are characterized by dilated and tortuous veins with a dysregulated vascular extracellular matrix. The purpose of the present study was to investigate the potential involvement of microRNA-21 (miR-21), a multifunctional microRNA tightly associated with extracellular matrix regulation, in the pathogenesis of VMs.

METHODS

The expression of miR-21, collagen I, III, and IV, transforming growth factor-β (TGF-β), and Smad3 (mothers against decapentaplegic homolog 3) was evaluated in VMs and normal skin tissue using in situ hybridization, immunohistochemistry, Masson trichrome staining, and real-time polymerase chain reaction. Human umbilical vein endothelial cells (HUVECs) were used to explore the underlying mechanisms.

RESULTS

miR-21 expression was markedly decreased in the VM specimens compared with normal skin, in parallel with downregulation of collagen I, III, and IV and the TGF-β/Smad3 pathway in VMs. Moreover, our data demonstrated that miR-21 positively regulated the expression of collagens in HUVECs and showed a positive association with the TGF-β/Smad3 pathway in the VM tissues. In addition, miR-21 was found to mediate TGF-β-induced upregulation of collagens in HUVECs. Our data have indicated that miR-21 and the TGF-β/Smad3 pathway could form a positive feedback loop to synergistically regulate endothelial collagen synthesis. In addition, TGF-β/Smad3/miR-21 feedback loop signaling was upregulated in bleomycin-treated HUVECs and VM specimens, which was accompanied by increased collagen deposition.

CONCLUSIONS

To the best of our knowledge, the present study has, for the first time, revealed downregulation of miR-21 in VMs, which might contribute to decreased collagen expression via the TGF-β/Smad3/miR-21 signaling feedback loop. These findings provide new information on the pathogenesis of VMs and might facilitate the development of new therapies for VMs.

The inhibitor miR-21 regulates macrophage polarization in an experimental model of chronic obstructive pulmonary disease

INTRODUCTION

In chronic obstructive pulmonary disease (COPD), macrophages play an indispensable role. In the lung tissues of COPD patients and smokers, macrophages can be observed to polarize towards M2 phenotype. The molecular mechanism of this process is unclear, and it has not been fully elucidated in COPD.

METHODS

We bought laboratory animals [C57BL/6 and miR-21^-/- C57BL/6(F1)] from the Jackson Laboratory. The model of COPD mice was established by cigarette smoke (CS) exposure combined with intraperitoneal injection of cigarette smoke extract (CSE). RT-PCR detected the expression levels of inflammatory factors and markers associated with M1 and M2 macrophages. The ratio of M2 macrophages to M1 macrophages was detected by immunohistochemical staining.

RESULTS

The level of miR-21 was increased in RAW264.7 cells intervened by CSE and in lung tissue and bone marrow-derived macrophages (BMDMs) from COPD mice. CSE can gradually over time increase the level of miR-21. The proportion of M2 macrophages to M1 macrophages had a positive correlation with miR-21. Knockdowning miR-21 can reduce lung tissue damage. CSE also increased the levels of related inflammatory factors and markers associated with M2 macrophages, and an miR-21 inhibitor can reverse this conversion.

CONCLUSIONS

We confirmed that CSE can lead to macrophage transformation to the M2 phenotype and an increase in the expression level of miR-21. Knockdown of the miR-21 gene could inhibit the transformation of macrophages to the M2 phenotype in COPD.

Metastatic pancreatic cancer: Mechanisms and detection (Review)

Pancreatic cancer (PC) is a lethal malignancy. Its prevalence rate remains low but continues to grow each year. Among all stages of PC, metastatic PC is defined as late-stage (stage IV) PC and has an even higher fatality rate. Patients with PC do not have any specific clinical manifestations. Most cases are inoperable at the time-point of diagnosis. Prognosis is also poor even with curative-intent surgery. Complications during surgery, postoperative pancreatic fistula and recurrence with metastatic foci make the management of metastatic PC difficult. While extensive efforts were made to improve survival outcomes, further elucidation of the molecular mechanisms of metastasis poses a formidable challenge. The present review provided an overview of the mechanisms of metastatic PC, summarizing currently known signaling pathways (e.g. epithelial-mesenchymal transition, NF-κB and KRAS), imaging that may be utilized for early detection and biomarkers (e.g. carbohydrate antigen 19-9, prostate cancer-associated transcript-1, F-box/LRR-repeat protein 7 and tumor stroma), giving insight into promising therapeutic targets.

Development of electrochemical biosensors for simultaneous multiplex detection of microRNA for breast cancer screening

A highly sensitive electrochemical biosensors has been developed for the detection of multiplex micro ribonucleic acids (miRNAs) by modifying an electrode with reduced graphene oxide/poly(2-aminobenzylamine)/gold nanoparticles and adopting porous, hollow silver-gold nanoparticles as tagged labeling with metal ions. In addition, an anti-deoxyribonucleic acid (DNA)-RNA hybrid [S9.6] antibody was used to detect different hybridized capture DNAs and miRNAs that can detect multiple miRNAs simultaneously. The developed electrochemical platform exhibits high selectivity, stability, and sensitivity with a wide linear range from 1 fM to 10 nM and a low detection limit of 0.98 fM, 3.58 fM, and 0.25 fM for miRNA-155, miRNA-21, and miRNA-16, respectively. In addition, the proposed electrochemical biosensor capable for the simultaneous detection of miRNA-155, miRNA-16, and miRNA-21, which are breast cancer biomarkers, in normal human serum, can be adopted and potentially used for breast cancer screening.

Expression of Salivary miRNA 21 in Oral Submucous Fibrosis (OSMF): An Observational Study

Objective:

To observe the expression patterns of salivary mRNA 21 in different stages and grades of OSMF and also in habitual areca nut chewers without OSMF.

Subjects and Methods

The study consisted of a total of 185 samples, where 61 patients had chewing habits (chewing gutkha and other forms of areca nut) and had OSMF (Group 1). 61 patients had chewing habits but did not have OSMF (Group 2), and 63 were normal healthy patients (control group) without any chewing habits (Group 3). Unstimulated saliva samples were collected from patients following the standard operating procedures. miRNA 21 was isolated and purified from saliva samples using the miRNeasy Mini Kit, Qiagen. The primers for miRNA relative quantification analysis were designed using the Primer Express software of Applied Biosystems. Quantification of all the samples was carried out using SYBR chemistry in an Applied Biosystems Real-Time PCR.

Results

There was no statistically significant difference between the demographic characteristics of patients. There was a statistically significant difference between the expressions of miRNA 21 amongst the three groups noted in Kruskal Wallis test. (<0.001*) A post hoc test was perfomed to confirm the statistical difference between patients within all three groups. There was no statistically significant difference noted between the OSMF group and patients with chewing habits group (G1 vs. G2 p: 0.10), but there was a significant difference when compared with normal patients. (G1 vs. G3 p: <0.001*) and (G2 vs. G3 <0.001*)

Conclusion

This study concludes that miRNA 21 is overexpressed in OSMF and chewing habit patients. But the expression levels were not significantly associated with the severity of the disease process. A long term and large scale studies are required to assess its application as a diagnostic profibrotic marker in OSMF.

SPTBN1 inhibits growth and epithelial-mesenchymal transition in breast cancer by downregulating miR-21

SPTBN1 (spectrin beta, non-erythrocytic 1) has been linked to tumor progression and epithelial-mesenchymal transition (EMT). However, the role of SPTBN1 has yet to be investigated in breast cancer. This study aimed to evaluate the viability, growth, and migration ability of the breast cancer cell line MDA-MB-231 and BT549 using CCK-8 assay, xenograft models, and Transwell assays. The expression of SPTBN1, EMT-related genes, and miRNA21 in breast cancer cells and tissues were assessed by quantitative real-time polymerase chain reaction (qPCR) and Western blot. SPTBN1 staining of breast cancer tissues was analyzed by the Human Protein Atlas databases. Both chromatin immunoprecipitation qPCR and immunofluorescence were performed to detect how SPTBN1 regulates miRNA21. Our results showed that the expression of SPTBN1 in primary breast cancer tumors was dramatically lower than that in normal tissues and that lower levels of SPTBN1 were associated with significantly shorter progression-free survival. We also discovered that the loss of SPTBN1 promotes EMT, the viability of MDA-MB-231 and BT549 in vitro, and the growth of MDA-MB-231 tumor xenografts in vivo by upregulating miR-21 level. Furthermore, loss of SPTBN1-mediated miR-21 upregulation was dependent on the stability and nuclear translocation of NF-κB p65. Therefore, SPTBN1 is a pivotal regulator that inhibits EMT and the growth of breast cancer.

Increased miR-21-3p and miR-487b-3p serum levels during anaphylactic reaction in food allergic children

BACKGROUND

Anaphylaxis is the most severe manifestation of allergic disorders. The poor knowledge of its molecular mechanisms often leads to under-diagnosis. MicroRNAs (miRNA) regulate physiologic and pathologic processes, and they have been postulated as promising diagnostic markers. The main objectives of this study were to characterize the human miRNA profile during anaphylaxis and to assess their capacity as diagnostic markers and determine their participation in the molecular mechanisms of this event.

METHODS

The miRNA serum profiles from the acute and baseline phase of 5 oral food-challenged anaphylactic children (<18 years old) were obtained by next-generation sequencing (NGS). From the panel of statistically significant miRNAs obtained, several candidates were selected and analyzed in 19 anaphylactic children by qPCR. We performed system biology analysis (SBA) on their target genes to identify main functions and canonical pathways. A functional in vitro assay was carried out incubating endothelial cells (ECs) in anaphylactic conditions.

RESULTS

The NGS identified 389 miRNAs among which 41 were significantly different between acute and baseline samples. The high levels of miR-21-3p (fold change = 2.28, P = .006) and miR-487b-3p (fold change = 1.04, P = .039) observed by NGS in acute serum samples were confirmed in a larger group of 19 patients. The SBA revealed molecular pathways related to the inflammation and immune system regulation. miR-21-3p increased intracellularly and in acute phase serum after EC stimulation.

CONCLUSIONS

These findings provide, for the first time, some insights into the anaphylactic miRNA serum profile in children and point to miR-21-3p and miR-487b-3p as candidate biomarkers. Furthermore, the SBA revealed a possible implication of these molecules in the underlying molecular mechanisms. Moreover, ECs increased miR-21-3p intracellularly and released it to the environment in response to anaphylaxis.

Advances in Multiplexed Paper-Based Analytical Devices for Cancer Diagnosis: A Review of Technological Developments

Cancer is one of the leading causes of death worldwide producing estimated cost of $161.2 billion in the US in 2017 only. Early detection of cancer would not only reduce cancer mortality rates but also dramatically reduce healthcare costs given that the 17 million new cancer cases in 2018 are estimated to grow 27.5 million new cases by 2040. Analytical devices based upon paper substrates could provide effective, rapid, and extremely low cost alternatives for early cancer detection compared to existing testing methods. However, low concentrations of biomarkers in body fluids as well as the possible association of any given biomarker with multiple diseases remain as one of the greatest challenges to widespread adoption of these paper-based devices. However, recent advances have opened the possibility of detecting multiple biomarkers within the same device, which could be predictive of a patient's condition with unprecedented cost-effectiveness. Accordingly, this review highlights the recent advancements in paper-based analytical devices with a multiplexing focus. The primary areas of interest include lateral flow assay and microfluidic paper-based assay formats, signal amplification approaches to enhance the sensitivity for a specific cancer type, along with current challenges and future outlook for the detection of multiple cancer biomarkers.

MicroRNA 21 Elicits a Pro-inflammatory Response in Macrophages, with Exosomes Functioning as Delivery Vehicles

MicroRNAs can regulate inflammatory responses by modulating macrophage polarization. Although microRNA miR-21 is linked to crucial processes involved in inflammatory responses, its precise role in macrophage polarization is controversial. In this study, we investigated the functional relevance of endogenous miRNA-21 and the role of exosomes. RAW 264.7 macrophages were transfected with miR-21 plasmid, and the inflammatory response was evaluated by flow cytometry, phagocytosis, and real-time PCR analysis of inflammatory cytokines. To understand the signaling pathways' role, the cells were treated with inhibitors specific for PI3K or NFĸB. Exosomes from transfected cells were used to study the paracrine action of miR-21 on naive macrophages. Overexpression of miR-21 resulted in significant upregulation of pro-inflammatory cytokines, pushing the cells towards a pro-inflammatory phenotype, with partial involvement of PI3K and NFĸB signal pathways. The cells also secreted miR-21 rich exosomes, which, on delivery to naive macrophages, caused them to exhibit pro-inflammatory activity. The presence of miR-21 inhibitor quenched the inflammatory response. This study validates the pro-inflammatory property of miR-21 with a tendency to foster an inflammatory milieu. Our findings also reinforce the dual importance of exosomal miR-21 as a biomarker and therapeutic target in inflammatory conditions.

May the Force Be with You (Or Not): The Immune System under Microgravity

All terrestrial organisms have evolved and adapted to thrive under Earth's gravitational force. Due to the increase of crewed space flights in recent years, it is vital to understand how the lack of gravitational forces affects organisms. It is known that astronauts who have been exposed to microgravity suffer from an array of pathological conditions including an impaired immune system, which is one of the most negatively affected by microgravity. However, at the cellular level a gap in knowledge exists, limiting our ability to understand immune impairment in space. This review highlights the most significant work done over the past 10 years detailing the effects of microgravity on cellular aspects of the immune system.

Ketogenic Diet in Cancer Prevention and Therapy: Molecular Targets and Therapeutic Opportunities

Although cancer is still one of the most significant global challenges facing public health, the world still lacks complementary approaches that would significantly enhance the efficacy of standard anticancer therapies. One of the essential strategies during cancer treatment is following a healthy diet program. The ketogenic diet (KD) has recently emerged as a metabolic therapy in cancer treatment, targeting cancer cell metabolism rather than a conventional dietary approach. The ketogenic diet (KD), a high-fat and very-low-carbohydrate with adequate amounts of protein, has shown antitumor effects by reducing energy supplies to cells. This low energy supply inhibits tumor growth, explaining the ketogenic diet's therapeutic mechanisms in cancer treatment. This review highlights the crucial mechanisms that explain the ketogenic diet's potential antitumor effects, which probably produces an unfavorable metabolic environment for cancer cells and can be used as a promising adjuvant in cancer therapy. Studies discussed in this review provide a solid background for researchers and physicians to design new combination therapies based on KD and conventional therapies.

Downregulation of miR-21 gene expression by CRE-Ter to modulate osteoclastogenesis: De Novo mechanism

miR-21 expression stimulates osteoclast cells in the context of osteoclastogenesis. A previous report showed that NFκB-miR-21 pathway could serve as an innovative alternative to devise therapeutics for healing diabetic ulcers. Furthermore, our study demonstrated that a highly water-soluble curcuminoids-rich extract (CRE-Ter) inhibits osteoclastogenesis through NFκB pathway. The interplay between miR-21 and CRE-Ter in osteoclastogenesis has not yet been investigated. In this study, we examined the relation of CRE-Ter and miR-21 gene expression in receptor of the nuclear factor κB (NFκB) ligand (RANKL) - induced murine monocyte/macrophage RAW 264.7 cells, osteoclast cells, in osteoclastogenesis. Effect of CRE-Ter on generation of intracellular reactive oxygen species (ROS) was estimated by dichlorofluorescein diacetate (DCFH-DA). The results reveal that CRE-Ter reduced expression levels of miR-21 gene in osteoclasts. The inhibitory effects of CRE-Ter on in vitro osteoclastogenesis were evaluated by reduction in tartrate-resistant acid phosphatase (TRAP) content, and by reduction in expression levels of an osteoclast-specific gene, cathepsin K. Treatment of the osteoclast cells with CRE-Ter suppressed RANKL-induced NFκB activation including phospho-NFκB-p65, and phospho IκBα proteins. Western blot analysis revealed that NFκB inhibitor up-regulated CRE-Ter-promoted expression of phospho-NFκB-p65. In addition, CRE-Ter dose-dependently inhibited phospho-Akt expression. CRE-Ter also dose-dependently reduced DNA binding activity of NFκB and Akt as revealed by EMSA. ChIP assay revealed binding of NFκB-p65 to miR-21 promoters. In conclusion, our results demonstrate that CRE-Ter downregulates miR-21 gene expression in osteoclasts via a de novo mechanism, NFκB- Akt-miR-21 pathway.

Direct detection of intracellular miRNA in living circulating tumor cells by tumor targeting nanoprobe in peripheral blood

Molecular analysis of circulating tumor cells (CTCs) is of critical significance for the non-invasive early detection of tumors. However, in situ detection of intracellular nucleic acids of CTCs in whole blood still remains challenge. By using a highly efficient tumor targeting nanoprobe, we realize in situ detection of microRNA-21 (miR-21) of living CTCs in unprocessed whole blood. In the nanoprobe, a catalytic hairpin assembly (CHA) system is complexed with protamine sulfate (PS), and then decorated by SYL3C conjugated hyaluronic acid (SHA) and hyaluronic acid (HA). The CHA system can be specifically delivered into living CTCs in whole blood, followed by hybridization between the CHA system and intracellular miR-21 in CTCs to induce strong fluorescence emission. After isolation of CTCs by membrane filtration, CTCs of cancer patients can be directly visualized by a fluorescence microscope for miR-21 detection at a single-cell level. Our study provides an efficient strategy to realize in situ genomic analysis of living CTCs in whole blood.

Breast Cancer Response to Therapy: Can microRNAs Lead the Way?

Breast cancer (BC) is a leading cause of death among women with malignant diseases. The selection of adequate therapies for highly invasive and metastatic BCs still represents a major challenge. Novel combinatorial therapeutic approaches are urgently required to enhance the efficiency of BC treatment. Recently, microRNAs (miRNAs) emerged as key regulators of the complex mechanisms that govern BC therapeutic resistance and susceptibility. In the present review we aim to critically examine how miRNAs influence BC response to therapies, or how to use miRNAs as a basis for new therapeutic approaches. We summarized recent findings in this rapidly evolving field, emphasizing the challenges still ahead for the successful implementation of miRNAs into BC treatment while providing insights for future BC management.The goal of this review was to propose miRNAs, that might simultaneously improve the efficacy of all four therapies that are the backbone of current BC management (radio-, chemo-, targeted, and hormone therapy). Among the described miRNAs, miR-21 and miR-16 emerged as the most promising, closely followed by miR-205, miR-451, miR-182, and miRNAs from the let-7 family. miR-21 inhibition might be the best choice for future improvement of invasive BC treatment.New therapeutic strategies of miRNA-based agents alongside current standard treatment modalities could greatly benefit BC patients. This review represents a guideline on how to navigate this elaborate puzzle.

LIX1-like protein promotes liver cancer progression via miR-21-3p-mediated inhibition of fructose-1,6-bisphosphatase

Limb and CNS expressed 1 like (LIX1L) is over-expressed in several types of tumors. However, the function of LIX1L in glucose metabolism and hepatocellular carcinoma (HCC) progression remains elusive. Here we report that LIX1L is over-expressed in human HCC tissues, which predicts unfavorable prognosis. LIX1L deficiency in vivo significantly attenuated liver cancer initiation in mice. Functional studies indicated that LIX1L overexpression elevated proliferation, migratory, invasive capacities of HCC cells in vitro, and promoted liver cancer growth and metastasis in vivo. LIX1L knockdown up-regulated fructose-1,6-bisphosphatase (FBP1) expression to reduce glucose consumption as well as lactate production. Mechanistically, LIX1L increased miR-21-3p expression, which targeted and suppressed FBP1, thereby promoting HCC growth and metastasis. MiR-21-3p inhibitor could abrogate LIX1L induced enhancement of cell migration, invasion, and glucose metabolism. Inhibition of miR-21-3p suppressed tumor growth in an orthotopic tumor model. Our results establish LIX1L as a critical driver of hepatocarcinogenesis and HCC progression, with implications for prognosis and treatment.

Role of Stress-Survival Pathways and Transcriptomic Alterations in Progression of Colorectal Cancer: A Health Disparities Perspective

Every year, more than a million individuals are diagnosed with colorectal cancer (CRC) across the world. Certain lifestyle and genetic factors are known to drive the high incidence and mortality rates in some groups of individuals. The presence of enormous amounts of reactive oxygen species is implicated for the on-set and carcinogenesis, and oxidant scavengers are thought to be important in CRC therapy. In this review, we focus on the ethnicity-based CRC disparities in the U.S., the negative effects of oxidative stress and apoptosis, and gene regulation in CRC carcinogenesis. We also highlight the use of antioxidants for CRC treatment, along with screening for certain regulatory genetic elements and oxidative stress indicators as potential biomarkers to determine the CRC risk and progression.

MiR-21 in the Cancers of the Digestive System and Its Potential Role as a Diagnostic, Predictive, and Therapeutic Biomarker

MicroRNAs (miRNAs) are small non-coding RNAs. They can regulate the expression of their target genes, and thus, their dysregulation significantly contributes to the development of cancer. Growing evidence suggests that miRNAs could be used as cancer biomarkers. As an oncogenic miRNA, the roles of miR-21 as a diagnostic and prognostic biomarker, and its therapeutic applications have been extensively studied. In this review, the roles of miR-21 are first demonstrated via its different molecular networks. Then, a comprehensive review on the potential targets and the current applications as a diagnostic and prognostic cancer biomarker and the therapeutic roles of miR-21 in six different cancers in the digestive system is provided. Lastly, a brief discussion on the challenges for the use of miR-21 as a therapeutic tool for these cancers is added.

Diets enriched in PUFAs at an early postimplantation stage prevent embryo resorptions and impaired mTOR signaling in the decidua from diabetic rats

Maternal diabetes increases the risk of embryo resorptions and impairs embryo development. Decidualization is crucial for embryo development and regulated by mTOR signaling. However, little is known about how maternal diabetes affects the decidua at early postimplantation stages and whether dietary treatments enriched in polyunsaturated fatty acids (PUFAs) can prevent decidual alterations. Here, we determined resorption rates, decidual mTOR pathways and markers of decidual function and remodeling in diabetic rats fed or not with diets enriched in PUFAs exclusively during the early postimplantation period. Pregestational streptozotocin-induced diabetic Albino Wistar rats and controls were fed or not with diets enriched in 6% sunflower oil or 6% chia oil (enriched in n-6 or n-3 PUFAs, respectively) on days 7, 8 and 9 of pregnancy and evaluated on day 9 of pregnancy. Maternal diabetes induced an 11-fold increase in embryo resorptions, which was prevented by both PUFAs-enriched diets despite no changes in maternal glycemia. The activity of mTOR pathway was decreased in the decidua from diabetic rats, an alteration prevented by the PUFAs-enriched diets. PUFAs-enriched diets prevented increased expression of Foxo1 (a negative regulator of mTOR) and reduced expression of miR-21 (a negative regulator of Foxo1). These diets also prevented reduced markers of decidual function (leukemia inhibitory factor and IGFBP1 expression and MMPs activity) in diabetic rat decidua. We identified the early post implantation as a crucial stage for pregnancy success, in which dietary PUFAs can protect diabetic pregnancies from embryo resorptions, decidual mTOR signaling impairments, and altered markers of decidual function and remodeling.

Identification of novel circulating microRNAs in advanced heart failure by next-generation sequencing

Aims

Risk stratification in patients with advanced chronic heart failure (HF) is an unmet need. Circulating microRNA (miRNA) levels have been proposed as diagnostic and prognostic biomarkers in several diseases including HF. The aims of the present study were to characterize HF‐specific miRNA expression profiles and to identify miRNAs with prognostic value in HF patients.

Methods and results

We performed a global miRNome analysis using next‐generation sequencing in the plasma of 30 advanced chronic HF patients and of matched healthy controls. A small subset of miRNAs was validated by real‐time PCR (P < 0.0008). Pearson's correlation analysis was computed between miRNA expression levels and common HF markers. Multivariate prediction models were exploited to evaluate miRNA profiles' prognostic role. Thirty‐two miRNAs were found to be dysregulated between the two groups. Six miRNAs (miR‐210‐3p, miR‐22‐5p, miR‐22‐3p, miR‐21‐3p, miR‐339‐3p, and miR‐125a‐5p) significantly correlated with HF biomarkers, among which N‐terminal prohormone of brain natriuretic peptide. Inside the cohort of advanced HF population, we identified three miRNAs (miR‐125a‐5p, miR‐10b‐5p, and miR‐9‐5p) altered in HF patients experiencing the primary endpoint of cardiac death, heart transplantation, or mechanical circulatory support implantation when compared with those without clinical events. The three miRNAs added substantial prognostic power to Barcelona Bio‐HF score, a multiparametric and validated risk stratification tool for HF (from area under the curve = 0.72 to area under the curve = 0.82).

Conclusions

This discovery study has characterized, for the first time, the advanced chronic HF‐specific miRNA expression pattern. We identified a few miRNAs able to improve the prognostic stratification of HF patients based on common clinical and laboratory values. Further studies are needed to validate our results in larger populations.

MicroRNA-21 inhibition attenuates airway inflammation and remodelling by modulating the transforming growth factor β-Smad7 pathway

BACKGROUND/AIMS

Current asthma therapies remain unsatisfactory for controlling airway remodelling in asthma. MicroRNA-21 is a key player in asthma pathogenesis, but the molecular mechanisms underlying its effects on airway remodelling are not completely understood. We investigated the effects of inhibition of microRNA-21 on allergic airway inflammation and remodelling.

METHODS

Female BALB/c mice were divided into four groups: control, ovalbumin-sensitized and -challenged for 3 months, microRNA-negative control-treated ovalbumin-treated, and microRNA-21 inhibitor-treated ovalbumin-treated groups. Parameters related to airway remodelling, cytokine production, airway inflammation, and airway hyperresponsiveness were compared between groups. Human bronchial smooth muscle cells were used in a mechanism study.

RESULTS

In this asthma model, ovalbumin-sensitized and -challenged mice exhibited allergic airway inf lammation and airway remodelling. MicroRNA-21 inhibitor-treated mice had fewer inflammatory cells, lower TH2 cytokine production, and suppressed parameters related to remodelling such as goblet cell hyperplasia, collagen deposition, hydroxyproline content, and expression of smooth muscle actin. Inhibition of microRNA-21 decreased transforming growth factor β1 expression and induced Smad7 expression in lung tissue. In human bronchial smooth muscle cells stimulated with transforming growth factor β1, microRNA-21 inhibition upregulated Smad7 expression and decreased markers of airway remodelling.

CONCLUSION

Inhibition of microRNA-21 had both anti-inflammatory and anti-remodelling effects in this model of ovalbumin-induced chronic asthma. Our data suggest that the microRNA-21-transforming growth factor β1-Smad7 axis modulates the pathogenesis of ovalbumin-induced chronic asthma and in human bronchial smooth muscle cells. MicroRNA-21 inhibitors may be a novel therapeutic target in patients with allergic asthma, especially those with airway remodelling.

NF-KappaB interacting LncRNA: Review of its roles in neoplastic and non-neoplastic conditions

NF-κB Interacting LncRNA (NKILA) is a long non-coding RNA (lncRNA) which has inhibitory roles on NF-κB. NF-κB regulates expression of several molecules participating in various crucial physiological reaction including immune responses, cell proliferation and differentiation, as well as cell death. Therefore, NKILA can be involved in the pathogenesis of a wide spectrum of human disorders. Numerous studies in hepatocellular carcinoma, breast cancer, melanoma, glioma and other types of neoplasms have indicated the role of NKILA in blockage of tumor growth and inhibition of metastasis. Further in vitro and in vivo assays including apoptosis assays, knock-down and knock-in experiments have verified such roles. In addition to its roles in neoplastic conditions, NKILA is involved in the pathogenesis of immune-related disorders. Dysregulation of expression of NKILA has been reported in patients with diverse conditions such as epilepsy, osteoarthritis, periodontitis and coronary artery disease. In this paper, we recapitulate the contribution of NKILA in neoplastic and non-neoplastic conditions.

A Super-Enhancer Driven by FOSL1 Controls miR-21-5p Expression in Head and Neck Squamous Cell Carcinoma

MiR-21-5p is one of the most common oncogenic miRNAs that is upregulated in many solid cancers by inhibiting its target genes at the posttranscriptional level. However, the upstream regulatory mechanisms of miR-21-5p are still not well documented in cancers. Here, we identify a super-enhancer associated with the MIR21 gene (MIR21-SE) by analyzing the MIR21 genomic regulatory landscape in head and neck squamous cell carcinoma (HNSCC). We show that the MIR21-SE regulates miR-21-5p expression in different HNSCC cell lines and disruption of MIR21-SE inhibits miR-21-5p expression. We also identified that a key transcription factor, FOSL1 directly controls miR-21-5p expression by interacting with the MIR21-SE in HNSCC. Moreover, functional studies indicate that restoration of miR-21-5p partially abrogates FOSL1 depletion-mediated inhibition of cell proliferation and invasion. Clinical studies confirmed that miR-21-5p expression is positively correlated with FOSL1 expression. These findings suggest that FOSL1-SE drives miR-21-5p expression to promote malignant progression of HNSCC

Elevated microRNA-21 Is a Brake of Inflammation Involved in the Development of Nasal Polyps

Background

CRSwNP is an inflammatory disease but the mechanism is not yet fully understood. MiR-21, a member of miRNAs, has been reported to play roles in mediating inflammation. However, the expression of miR-21 and its role in patients with CRSwNP remain elusive.

Methods

Turbinates from control subjects, uncinate processes from CRSsNP, polyp tissues from CRSwNP, and nasal epithelial cells brushed from nasal mucosa were collected. The expression of miR-21 and cytokines in nasal tissues and epithelial cells were detected by qPCR. The localization of miR-21 was detected by ISH, and its target was identified by bioinformation analysis, qPCR, IHC, WB, and luciferase reporter system. The protein and mRNA of PDCD4 and NF-κB P65 were determined by WB and qPCR after miR-21 transfection in HNEpC. The role of miR-21 on cytokines was analyzed in HNEpC and nasal polyp explants.

Results

MiR-21 was upregulated in CRSwNP relative to control subjects by qPCR, which was determined mainly in nasal epithelial cells of CRSwNP by ISH. Both pro-inflammation cytokines (IL-1β, IL-6, IL-8, IL-25, and TSLP) and a suppressive cytokine (IL-10) were overexpressed in the epithelial cells of CRSwNP. The expression of miR-21 was positively correlated with IL-10 and negatively correlated with IL-6, IL-8, IL-33, and TSLP in the epithelial cells of CRSwNP. As a potential target of miR-21, the expression of PDCD4 was negatively correlated with miR-21 in CRSwNP. In HNEpC, miR-21 could reduce the expression of PDCD4 at both mRNA and protein levels, and bioinformation analysis and luciferase reporter system confirmed PDCD4 as one target of miR-21. Furthermore, miR-21 could decrease the activation of NF-κB and increase IL-10 mRNA. Both SEB and LPS could elevate miR-21, with IL-25, IL-33, TSLP induced by SEB and IL-1β, IL-6, IL-8 induced by LPS, while the miR-21 could regulate the expression of IL-33, TSLP, IL-1β, IL- 6 and IL-8 in vitro and ex vivo. Clinically, miR-21 expression was inversely correlated with the Lund-Mackay CT scores and the Lund-Kennedy scores in CRSwNP.

Conclusion

MiR-21 could be a prominent negative feedback factor in the inflammation process to attenuate the expression of pro-inflammatory cytokines, thereby playing an anti-inflammation role in CRSwNP.

PMDFI: Predicting miRNA-Disease Associations Based on High-Order Feature Interaction

MicroRNAs (miRNAs) are non-coding RNA molecules that make a significant contribution to diverse biological processes, and their mutations and dysregulations are closely related to the occurrence, development, and treatment of human diseases. Therefore, identification of potential miRNA–disease associations contributes to elucidating the pathogenesis of tumorigenesis and seeking the effective treatment method for diseases. Due to the expensive cost of traditional biological experiments of determining associations between miRNAs and diseases, increasing numbers of effective computational models are being used to compensate for this limitation. In this study, we propose a novel computational method, named PMDFI, which is an ensemble learning method to predict potential miRNA–disease associations based on high-order feature interactions. We initially use a stacked autoencoder to extract meaningful high-order features from the original similarity matrix, and then perform feature interactive learning, and finally utilize an integrated model composed of multiple random forests and logistic regression to make comprehensive predictions. The experimental results illustrate that PMDFI achieves excellent performance in predicting potential miRNA–disease associations, with the average area under the ROC curve scores of 0.9404 and 0.9415 in 5-fold and 10-fold cross-validation, respectively.

DF-MDA: An effective diffusion-based computational model for predicting miRNA-disease association

It is reported that microRNAs (miRNAs) play an important role in various human diseases. However, the mechanisms of miRNA in these diseases have not been fully understood. Therefore, detecting potential miRNA-disease associations has far-reaching significance for pathological development and the diagnosis and treatment of complex diseases. In this study, we propose a novel diffusion-based computational method, DF-MDA, for predicting miRNA-disease association based on the assumption that molecules are related to each other in human physiological processes. Specifically, we first construct a heterogeneous network by integrating various known associations among miRNAs, diseases, proteins, long non-coding RNAs (lncRNAs), and drugs. Then, more representative features are extracted through a diffusion-based machine-learning method. Finally, the Random Forest classifier is adopted to classify miRNA-disease associations. In the 5-fold cross-validation experiment, the proposed model obtained the average area under the curve (AUC) of 0.9321 on the HMDD v3.0 dataset. To further verify the prediction performance of the proposed model, DF-MDA was applied in three significant human diseases, including lymphoma, lung neoplasms, and colon neoplasms. As a result, 47, 46, and 47 out of top 50 predictions were validated by independent databases. These experimental results demonstrated that DF-MDA is a reliable and efficient method for predicting potential miRNA-disease associations.

In Situ Modulating DNAzyme Activity and Internalization Behavior with Acid-Initiated Reconfigurable DNA Nanodevice for Activatable Theranostic

DNAzyme-mediated gene silencing was still challenged by off-target toxicity. In this study, we developed a split DNAzyme-based nanodevice (sDz-ND) that leveraged acidic tumor microenvironments to drive in situ assembly, thus modulating internalization behavior and silencing activity of DNAzymes. sDz-ND consisted of two different modules, which functionalized with split DNAzyme fragments, respectively. At psychological pH (∼7.4), the two modules were monodispersed, showing cleavage anergy and quenched fluorescence. At pH 6.3, the separated modules could cross-link with each other to form integrated sDz-ND, resulting activation of theranostic function. Meanwhile, the increased particle size and acquired multivalent effect favored 2.1-fold enhanced binding ability, which further facilitated rapid endocytosis of sDz-ND into target cancer cells, then allowing DNAzyme mediated gene silencing. The strategy provides a promising and general concept for precise tumor imaging and gene therapy.

Retinoic acid abrogates LPS-induced inflammatory response via negative regulation of NF-kappa B/miR-21 signaling

CONTEXT

Macrophages are essential components of the immune system, with significant roles in inflammation modulation. They can be activated into pro-inflammatory M1 or anti-inflammatory M2 phenotypes, depending on their micro-environment. Molecular factors that modulate macrophage polarization are hot targets for therapeutic strategies to counter chronic inflammatory pathological conditions.

OBJECTIVE

The current study aimed to elucidate the molecular mechanisms by which Retinoic acid (RA), a potent immunomodulator, suppresses LPS-induced inflammatory response in macrophages.

MATERIALS AND METHODS

RAW 264.7 macrophages were treated with RA and/or LPS, and analyzed for inflammatory genes and miR-21 by PCR. The roles of miR-21 and NF-ĸB signaling pathway were also assessed by knock-down experiments, immunofluorescence, and ChIP assays.

RESULTS

Pretreatment with RA quenched the LPS-induced inflammatory responses, including phagocytosis, ROS generation, and NO production. RA shifted the polarization away from the M1 state by negative regulation of IKKα/β, p65, and miR-21. RA hindered the phosphorylation of IKKα/β, translocation of p65 into the nucleus, and the subsequent upregulation of miR-21. Knock-in and knock-down experiments showed that miR-21 is central for the polarization shift toward the pro-inflammatory M1 state.

CONCLUSION

miR-21 is involved in the LPS-induced pro-inflammatory profile of macrophages and that RA negatively regulates the inflammatory response by targeting NF-ĸB/miR-21 signaling. Our data exposes RA's potential as a pharmacological agent to manipulate miR-21 and counteract hyper-inflammatory response.

Predictive value of miRNA-21 on coronary restenosis after percutaneous coronary intervention in patients with coronary heart disease: A protocol for systematic review and meta-analysis

BACKGROUND

Evidence reveals that microRNA (miRNA) can predict coronary restenosis in patients suffering from coronary heart disease (CHD) after percutaneous coronary intervention (PCI). Perhaps, miRNA-21 is a promising biomarker for the diagnosis of coronary restenosis after PCI. However, the accuracy of miRNA-21 has not been systematically evaluated. Therefore, it is necessary to perform meta-analysis to certify the diagnostic values of miRNA-21 on coronary restenosis after PCI.

METHODS

China National Knowledge Infrastructure, Wanfang, VIP, and China Biology Medicine disc, PubMed, EMBASE, Cochrane Library, and Web of Science were searched for relevant studies to explore the potential diagnostic values of miRNA-21 on coronary restenosis after PCI from inception to January 2021. All data were extracted by 2 experienced researchers independently. The risk of bias about the meta-analysis was confirmed by the Quality Assessment of Diagnostic Accuracy Studies-2. The data extracted were synthesized and heterogeneity was investigated as well. All of the above statistical analyses were carried out with Stata 16.0.

RESULTS

This study proved the pooled diagnostic performance of miRNA-21 on coronary restenosis after PCI.

CONCLUSION

This study clarified confusions about the specificity and sensitivity of miRNA-21 on coronary restenosis after PCI, thus further guiding their promotion and application.

ETHICS AND DISSEMINATION

Ethical approval is not required for this study. The systematic review will be published in a peer-reviewed journal, presented at conferences, and shared on social media platforms. This review would be disseminated in a peer-reviewed journal or conference presentations.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/356QK.

The number and periodicity of seizures induce cardiac remodeling and changes in micro-RNA expression in rats submitted to electric amygdala kindling model of epilepsy

Generalized tonic-clonic seizures (GTCS) are the main risk factor for sudden unexpected death in epilepsy (SUDEP). Also, among the several mechanisms underlying SUDEP there is the cardiac dysfunction. So, we aimed to evaluate the impact of the number of seizures on heart function and morphology in rats with epilepsy. Rats were randomized into three groups: Sham (without epilepsy), 5 S, and 10 S groups, referred as rats with epilepsy with a total of 5 or 10 GTCS, respectively. Epilepsy was induced by electrical amygdala kindling. The ventricular function was analyzed by the Langendorff technique and challenged by ischemia/reperfusion protocol. Cardiac fibrosis and hypertrophy were analyzed by histology. We also analyzed cardiac metalloproteinases (MMP2 and MMP9), ERK 1/2 and phosphorylated ERK1/2 (P-ERK) by western blot; microRNA-21 and -320 by RT-PCR; and oxidative stress (TBARS, catalase activity and nitrite) by biochemical analysis. Only the 5S group presented decreased values of ventricular function at before ischemia/reperfusion (baseline): intraventricular systolic pressure, developed intraventricular pressure, positive and negative dP/dt. During ischemia/reperfusion protocol, the variation of the ventricular function did not differ among groups. Both 5S and 10S groups had increased cardiomyocyte hypertrophy and fibrosis compared to Sham, but in the 5S group, these alterations were higher than in the 10S group. The 5S group increased in microRNA-21 and decreased in microRNA-320 expression compared to Sham and the 10S group. The 10S group increased in MMP9 and decreased in P-ERK/ERK expression, and increased in nitrite content compared to both Sham and the 5S group. Therefore, seizures impair cardiac function and morphology, probably through microRNA modulation. The continuation of seizures seems to exert a preconditioning-like stimulus that fails to compensate the cardiac tissue alteration.

MicroRNA-21 Plays Multiple Oncometabolic Roles in the Process of NAFLD-Related Hepatocellular Carcinoma via PI3K/AKT, TGF-β, and STAT3 Signaling

MicroRNA-21 (miR-21) is one of the most frequently upregulated miRNAs in liver diseases such as nonalcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma (HCC). However, mechanistic pathways that connect NAFLD and HCC remain elusive. We developed a doxycycline (Dox)-inducible transgenic zebrafish model (LmiR21) which exhibited an upregulation of miR-21 in the liver, which in turn induced the full spectrum of NAFLD, including steatosis, inflammation, fibrosis, and HCC, in the LmiR21 fish. Diethylnitrosamine (DEN) treatment led to accelerated liver tumor formation and exacerbated their aggressiveness. Moreover, prolonged miR-21 expression for up to ten months induced nonalcoholic steatohepatitis (NASH)-related HCC (NAHCC). Immunoblotting and immunostaining confirmed the presence of miR-21 regulatory proteins (i.e., PTEN, SMAD7, p-AKT, p-SMAD3, and p-STAT3) in human nonviral HCC tissues and LmiR21 models. Thus, we demonstrated that miR-21 can induce NAHCC via at least three mechanisms: First, the occurrence of hepatic steatosis increases with the decrease of ptenb, pparaa, and activation of the PI3K/AKT pathway; second, miR-21 induces hepatic inflammation (or NASH) through an increase in inflammatory gene expression via STAT3 signaling pathways, and induces liver fibrosis through hepatic stellate cell (HSC) activation and collagen deposition via TGF-β/Smad3/Smad7 signaling pathways; finally, oncogenic activation of Smad3/Stat3 signaling pathways induces HCC. Our LmiR21 models showed similar molecular pathology to the human cancer samples in terms of initiation of lipid metabolism disorder, inflammation, fibrosis and activation of the PI3K/AKT, TGF-β/SMADs and STAT3 (PTS) oncogenic signaling pathways. Our findings indicate that miR-21 plays critical roles in the mechanistic perspectives of NAHCC development via the PTS signaling networks.

A distance-based capillary biosensor using wettability alteration

Distance-based detection methods with a quantitative readout are of great significance to point-of-care testing (POCT), are low-cost and user-friendly, and can be integrated into portable analytical devices. Here, we submit a visual quantitative distance-based sensor by capillary force alteration in a capillary tube. This sensor converts the wettability alteration caused by the target molecules into a capillary rise height signal. Moreover, the sensor profits from isothermal amplification technology, achieving the detection of miRNAs with high sensitivity and specificity by visually reading the height of the water in the capillary tube. The proposed biosensor shows great potential in routine clinical diagnosis as well as POCT in resource-limited settings.

Molecular Insights into the Potential of Extracellular Vesicles Released from Mesenchymal Stem Cells and Other Cells in the Therapy of Hematologic Malignancies

Hematologic cancer encompasses the heterogeneous group of neoplasms that affect different stages of blood cell linages. Despite the significant improvements made in the new modalities of anticancer therapy, many forms of blood cancer remain untreatable, putting the afflicted patients at high risk of death. Therefore, there has been an urgent need for novel therapy to improve the clinical outcomes of patients with blood cancer. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have been reported to possess an anticancer activity. This review discusses (i) the therapeutic potential of MSC-EVs against blood cancer, (ii) the possibility of using EVs from sources other than MSCs as a mean for blood cancer vaccination and drug delivery, and (iii) areas to be optimized for MSC-EV-based clinical application on blood malignancies.

Enhancement of Therapies for Glioblastoma (GBM) Using Nanoparticle-based Delivery Systems

Glioblastoma multiforme (GBM) is the most aggressive type of malignant brain tumor. Current FDA-approved treatments include surgical resection, radiation, and chemotherapy, while hyperthermia, immunotherapy, and most relevantly, nanoparticle (NP)-mediated delivery systems or combinations thereof have shown promise in preclinical studies. Drug-carrying NPs are a promising approach to brain delivery as a result of their potential to facilitate the crossing of the blood-brain barrier (BBB) via two main types of transcytosis mechanisms: adsorptive-mediated transcytosis (AMT) and receptor-mediated transcytosis (RMT). Their ability to accumulate in the brain can thus provide local sustained release of tumoricidal drugs at or near the site of GBM tumors. NP-based drug delivery has the potential to significantly reduce drug-related toxicity, increase specificity, and consequently improve the lifespan and quality of life of patients with GBM. Due to significant advances in the understanding of the molecular etiology and pathology of GBM, the efficacy of drugs loaded into vectors targeting this disease has increased in both preclinical and clinical settings. Multitargeting NPs, such as those incorporating multiple specific targeting ligands, are an innovative technology that can lead to decreased off-target effects while simultaneously having increased accumulation and action specifically at the tumor site. Targeting ligands can include antibodies, or fragments thereof, and peptides or small molecules, which can result in a more controlled drug delivery system compared to conventional drug treatments. This review focuses on GBM treatment strategies, summarizing current options and providing a detailed account of preclinical findings with prospective NP-based approaches aimed at improving tumor targeting and enhancing therapeutic outcomes for GBM patients.

NLRP3 Inflammasome at the Interface of Inflammation, Endothelial Dysfunction, and Type 2 Diabetes

Type 2 diabetes mellitus (T2DM), accounting for 90-95% cases of diabetes, is characterized by chronic inflammation. The mechanisms that control inflammation activation in T2DM are largely unexplored. Inflammasomes represent significant sensors mediating innate immune responses. The aim of this work is to present a review of links between the NLRP3 inflammasome, endothelial dysfunction, and T2DM. The NLRP3 inflammasome activates caspase-1, which leads to the maturation of pro-inflammatory cytokines interleukin 1β and interleukin 18. In this review, we characterize the structure and functions of NLRP3 inflammasome as well as the most important mechanisms and molecules engaged in its activation. We present evidence of the importance of the endothelial dysfunction as the first key step to activating the inflammasome, which suggests that suppressing the NLRP3 inflammasome could be a new approach in depletion hyperglycemic toxicity and in averting the onset of vascular complications in T2DM. We also demonstrate reports showing that the expression of a few microRNAs that are also known to be involved in either NLRP3 inflammasome activation or endothelial dysfunction is deregulated in T2DM. Collectively, this evidence suggests that T2DM is an inflammatory disease stimulated by pro-inflammatory cytokines. Finally, studies revealing the role of glucose concentration in the activation of NLRP3 inflammasome are analyzed. The more that is known about inflammasomes, the higher the chances to create new, effective therapies for patients suffering from inflammatory diseases. This may offer potential novel therapeutic perspectives in T2DM prevention and treatment.

From Liver Cirrhosis to Cancer: The Role of Micro-RNAs in Hepatocarcinogenesis

In almost all cases, hepatocellular carcinoma (HCC) develops as the endpoint of a sequence that starts with chronic liver injury, progresses to liver cirrhosis, and finally, over years and decades, results in liver cancer. Recently, the role of non-coding RNA such as microRNA (miRNA) has been demonstrated in the context of chronic liver diseases and HCC. Moreover, data from a phase II trial suggested a potential role of microRNAs as therapeutics in hepatitis-C-virus infection, representing a significant risk factor for development of liver cirrhosis and HCC. Despite progress in the clinical management of chronic liver diseases, pharmacological treatment options for patients with liver cirrhosis and/or advanced HCC are still limited. With their potential to regulate whole networks of genes, miRNA might be used as novel therapeutics in these patients but could also serve as biomarkers for improved patient stratification. In this review, we discuss available data on the role of miRNA in the transition from liver cirrhosis to HCC. We highlight opportunities for clinical translation and discuss open issues applicable to future developments.

Triggered Dimerization and Trimerization of DNA Tetrahedra for Multiplexed miRNA Detection and Imaging of Cancer Cells

The reversible and switchable triggered reconfiguration of tetrahedra nanostructures from monomer tetrahedra structures into dimer or trimer structures is introduced. The triggered bridging of monomer tetrahedra by K⁺ -ion-stabilized G-quadruplexes or T-A•T triplexes leads to dimer or trimer tetrahedra structures that are separated by crown ether or basic pH conditions, respectively. The signal-triggered dimerization/trimerization of DNA tetrahedra structures is used to develop multiplexed miRNA-sensing platforms, and the tetrahedra mixture is used for intracellular sensing and imaging of miRNAs.

MicroRNA Modulation of Host Immune Response and Inflammation Triggered by Helicobacter pylori

Helicobacter pylori (H. pylori) remains the most-researched etiological factor for gastric inflammation and malignancies. Its evolution towards gastric complications is dependent upon host immune response. Toll-like receptors (TLRs) recognize surface and molecular patterns of the bacterium, especially the lipopolysaccharide (LPS), and act upon pathways, which will finally lead to activation of the nuclear factor-kappa B (NF-kB), a transcription factor that stimulates release of inflammatory cytokines. MicroRNAs (MiRNAs) finely modulate TLR signaling, but their expression is also modulated by activation of NF-kB-dependent pathways. This review aims to focus upon several of the most researched miRNAs on this subject, with known implications in host immune responses caused by H. pylori, including let-7 family, miRNA-155, miRNA-146, miRNA-125, miRNA-21, and miRNA-221. TLR-LPS interactions and their afferent pathways are regulated by these miRNAs, which can be considered as a bridge, which connects gastric inflammation to pre-neoplastic and malignant lesions. Therefore, they could serve as potential non-invasive biomarkers, capable of discriminating H. pylori infection, as well as its associated complications. Given that data on this matter is limited in children, as well as for as significant number of miRNAs, future research has yet to clarify the exact involvement of these entities in the progression of H. pylori-associated gastric conditions.

An autoregulatory feedback loop of miR-21/VMP1 is responsible for the abnormal expression of miR-21 in colorectal cancer cells

MircoRNA-21 (miR-21) was found to be highly expressed in various solid tumors, and its oncogenic properties have been extensively studied in recent years. However, the reason why miR-21 is highly expressed in various tumors remains elusive. Here, we found that the expression of miR-21 was negatively correlated with the expression of vacuole membrane protein-1 (VMP1) in colorectal cancer. Transcription of VMP1 activated either by small activating RNA (saRNA) or transcriptional activator GLI3 inhibited miR-21 expression through reducing its transcripts of VMP1-miR-21 and pri-miR-21, while no significant change in miR-21 expression after exogenous overexpression VMP1 in colorectal cancer cell HCT116. Considering the overlapping location of VMP1 and miR-21 gene in genome, the result suggested that the transcription of miR-21 was inhibited by the endogenous transcriptional activation of VMP1. Furthermore, we identified that miR-21 inhibited the activation and nuclear translocation of transcription factor EB (TFEB) through reducing the inhibitory of PTEN on AKT phosphorylation, which can directly activate the transcription of VMP1. Loss of miR-21 significantly increased VMP1 expression, which could be blocked by PTEN inhibitor (VO-Ohpic) or TFEB siRNA. These results showed that miR-21 negatively regulated VMP1 transcription through the PTEN/AKT/TFEB pathway, and TFEB-induced transcriptional activation of VMP1 could inhibit miR-21 expression, thus forming a feedback regulatory loop of miR-21/VMP1. We further found that disrupting the miR-21/VMP1 feedback loop will decrease the expression of miR-21, reduce the malignancy, and increase their sensitivity to 5-fluorouracil in colorectal cancer cells. Taken together, our results revealed a novel regulatory mechanism of miR-21 expression, and targeting the miR-21/VMP1 feedback loop may provide a new approach to inhibit miR-21 expression in colorectal cancer cells.

Non-Coding RNAs as Mediators of Epigenetic Changes in Malignancies

Non-coding RNAs (ncRNAs) are untranslated RNA molecules that regulate gene expressions. NcRNAs include small nuclear RNAs (snRNAs), small nucleolar RNAs (snoRNAs), ribosomal RNAs (rRNAs), transfer RNAs (tRNAs), circular RNAs (cRNAs) and piwi-interacting RNAs (piRNAs). This review focuses on two types of ncRNAs: microRNAs (miRNAs) or short interfering RNAs (siRNAs) and long non-coding RNAs (lncRNAs). We highlight the mechanisms by which miRNAs and lncRNAs impact the epigenome in the context of cancer. Both miRNAs and lncRNAs have the ability to interact with numerous epigenetic modifiers and transcription factors to influence gene expression. The aberrant expression of these ncRNAs is associated with the development and progression of tumors. The primary reason for their deregulated expression can be attributed to epigenetic alterations. Epigenetic alterations can cause the misregulation of ncRNAs. The experimental evidence indicated that most abnormally expressed ncRNAs impact cellular proliferation and apoptotic pathways, and such changes are cancer-dependent. In vitro and in vivo experiments show that, depending on the cancer type, either the upregulation or downregulation of ncRNAs can prevent the proliferation and progression of cancer. Therefore, a better understanding on how ncRNAs impact tumorigenesis could serve to develop new therapeutic treatments. Here, we review the involvement of ncRNAs in cancer epigenetics and highlight their use in clinical therapy.

MiRNAs directly targeting the key intermediates of biological pathways in pancreatic cancer

Pancreatic Cancer (PC) is a severe form of malignancy all over the world. Delayed diagnosis and chemoresistance are the major factors contributing to its poor prognosis and high mortality rate. The genetic and epigenetic regulations of biological pathways further complicate the progression and chemotherapy response to this cancer. MicroRNAs (MiRNAs) involvement has been observed in all types of cancers including PC. The understanding and categorization of miRNAs according to their specific targets are very important to develop early diagnostic and therapeutic interventions. The current review, emphasizing recent research findings, has categorized miRNAs that directly target the potential onco-factors that act as central converging signal-nodes in five major cancer-related pathways i.e., MAPK/ERK, JAK/STAT, Wnt/β-catenin, AKT/mTOR, and TGFβ in PC. The therapeutic perspectives of miRNAs in PC have also been discussed. This will help to understand the interplay of various miRNAs within foremost signaling pathways and develop a multifactorial approach to treat difficult-to-treat PC.