The Promising Role of miR-21 as a Cancer Biomarker and Its Importance in RNA-Based Therapeutics

Engineering supramolecular dynamics of self-assembly and turnover of oncogenic microRNAs to drive their synergistic destruction in tumor models

Rationally-engineered functional biomaterials offer the opportunity to interface with complex biology in a predictive, precise, yet dynamic way to reprogram their behaviour and correct shortcomings. Success here may lead to a desired therapeutic effect against life-threatening diseases, such as cancer. Here, we engineered "Crab"-like artificial ribonucleases through coupling of peptide and nucleic acid building blocks, capable of operating alongside and synergistically with intracellular enzymes (RNase H and AGO2) for potent destruction of oncogenic microRNAs. "Crab"-like configuration of two catalytic peptides ("pincers") flanking the recognition oligonucleotide was instrumental here in providing increased catalytic turnover, leading to ≈30-fold decrease in miRNA half-life as compared with that for "single-pincer" conjugates. Dynamic modeling of miRNA cleavage illustrated how such design enabled "Crabs" to drive catalytic turnover through simultaneous attacks at different locations of the RNA-DNA heteroduplex, presumably by producing smaller cleavage products and by providing toeholds for competitive displacement by intact miRNA strands. miRNA cleavage at the 5'-site, spreading further into double-stranded region, likely provided a synergy for RNase H1 through demolition of its loading region, thus facilitating enzyme turnover. Such synergy was critical for sustaining persistent disposal of continually-emerging oncogenic miRNAs. A single exposure to the best structural variant (Crab-p-21) prior to transplantation into mice suppressed their malignant properties and reduced primary tumor volume (by 85 %) in MCF-7 murine xenograft models.

Role of MicroRNA-21 in Prostate Cancer Progression and Metastasis: Molecular Mechanisms to Therapeutic Targets

The role of noncoding RNA has made remarkable progress in understanding progression, metastasis, and metastatic castration-resistant prostate cancer (mCRPC). A better understanding of the miRNAs has enhanced our knowledge of their targeting mainly at the therapy level in solid tumors, such as prostate cancer (PCa). microRNAs (miRNAs) belong to a class of endogenous RNA that deficit encoded proteins. Therefore, the role of miRNAs has been well-coined in the progression and development of PCa. miR-21 has a dual nature in its work both as a tumor suppressor and oncogenic role, but most of the recent studies showed that miR-21 is a tumor promoter and also is involved in castration-resistant prostate cancer (CRPC). Upregulation of miR-21 suppresses programmed cell death and inducing metastasis and castration resistant in PCa. miR-21 is involved in the different stages, such as proliferation, angiogenesis, migration, and invasion, and plays an important role in the progression, metastasis, and advanced stages of PCa. Recently, various studies directly linked the role of high levels of miR-21 with a poor therapeutic response in the patient of PCa. In the present review, we have explained the molecular mechanisms/pathways of miR-21 in PCa progression, metastasis, and castration resistant and summarized the role of miR-21 in diagnosis and therapeutic levels in PCa. In addition, we have spotlighted the recent therapeutic strategies for targeting different stages of PCa.

Urinary extracellular vesicles-encapsulated miRNA signatures: A new paradigm for urinary bladder cancer diagnosis and classification

Bladder cancer (BCa) stands as prevalent malignancy of the urinary system globally, especially among men. The clinical classification of BCa into non-muscle invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC) is crucial for prognosis and treatment decisions. However, challenges persist in current diagnostic methods like Urine cytopathology that shows poor sensitivity therefore compromising on accurately diagnosing and monitoring BCa. In recent years, research has emphasized the importance of identifying urine and blood-based specific biomarkers for BCa that can enable early and precise diagnosis, effective tumor classification, and monitoring. The convenient proximity of urine with the urinary bladder epithelium makes urine a good source of noninvasive biomarkers, in particular urinary EVs because of the packaged existence of tumor-associated molecules. Therefore, the review assesses the potential of urinary extracellular vesicles (uEVs) as noninvasive biomarkers for BCa. We have elaborately reviewed and discussed the research that delves into the role of urinary EVs in the context of BCa diagnosis and classification. Extensive research has been dedicated to investigating differential microRNA (miRNA) expressions, with the goal of establishing distinct, noninvasive biomarkers for BCa. The identification of such biomarkers has the potential to revolutionize early detection, risk stratification, therapeutic interventions, and ultimately, the long-term prognosis of BCa patients. Despite notable advancements, inconsistencies persist in the biomarkers identified, methodologies employed, and study populations. This review meticulously compiles reported miRNA biomarkers, critically assessing the variability and discrepancies observed in existing research. By synthesizing these findings, the article aims to direct future studies toward a more cohesive and dependable approach in BCa biomarker identification, fostering progress in patient care and management.

Sex dimorphic response to osteocyte miR21 deletion in murine calvaria bone as determined by RNAseq analysis

Low levels of microRNA (miR) 21 may explain the higher osteocyte apoptosis with Cx43-deficient and aged female mice. However, miR21 exerts a sex-divergent role in osteocytes, regulating bone mass and architecture through non-cell autonomous effects on osteoblasts and osteoclasts, via sex-specific regulation of osteocyte cytokine production. miR21 deficiency improves bone strength in females, and, to a higher extent, in male miR21-deficient mice. To understand the molecular basis for the effects of miR21 deletion, mRNA was isolated from miR21fl/fl (controls) or miR21-deficient (by deletion in cells expressing Cre recombinase under the control of the 8 kb fragment of the DMP1 promoter: miR21ΔOt mice). miR21 was 50% lower in miR21ΔOt whole calvaria bone compared to control mice of the corresponding sex. RNAseq was performed in 4 samples/sex and genotype. There were 152 genes with <.05 P-value and >1 absolute log2 fold change in the male data analysis, and expression of most genes was higher in the miR21fl/fl group. Two of the genes, Actn3 and Myh4, had a false discovery rate < 0.1. Gene enrichment analysis of significant genes on both KEGG pathways and gene ontology (GO) gene sets shows that the significant genes were enriched in muscle contraction. Some muscle-related genes like Actn3 were included in multiple significant pathways. For females, only 65 genes had P-value <.05 and >1 absolute log2 fold change. Yet, no significant KEGG or GO pathways, including ≥5 significant genes, were seen, and no overlap of significant genes was found between male and female samples. Therefore, deletion of miR21 has a stronger effect on male transcriptome in calvaria, compared to females. Further, no enrichment of any pathway was detected in female samples. Thus, either there are no differences between 2 groups in female or the effect size is small, and a larger sample size is needed to uncover miR21-dependent differences.

A pipeline for the development and analysis of extracellular vesicle-based transcriptomic biomarkers in molecular diagnostics

Extracellular vesicles are shed by every cell type and can be found in any biofluid. They contain different molecules that can be utilized as biomarkers, including several RNA species which they protect from degradation. Here, we present a pipeline for the development and analysis of extracellular vesicle-associated transcriptomic biomarkers that our group has successfully applied multiple times. We highlight the key steps of the pipeline and give particular emphasis to the necessary quality control checkpoints, which are linked to numerous available guidelines that should be considered along the workflow. Our pipeline starts with patient recruitment and continues with blood sampling and processing. The purification and characterization of extracellular vesicles is explained in detail, as well as the isolation and quality control of extracellular vesicle-associated RNA. We point out the possible pitfalls during library preparation and RNA sequencing and present multiple bioinformatic tools to pinpoint biomarker signature candidates from the sequencing data. Finally, considerations and pitfalls during the validation of the biomarker signature using RT-qPCR will be elaborated.

MiR-136-5p in cancer: Roles, mechanisms, and chemotherapy resistance

MicroRNAs (miRNAs) have emerged as important regulators of gene expression, and the deregulation of their activity has been linked to the onset and progression of a variety of human malignancies. Among these miRNAs, miR-136-5p has attracted significant attention due to its diverse roles in cancer biology. Mostly, miR-136-5p is downregulated in malignancies. It could inhibit viability, proliferation, migration, invasion and promote apoptosis of tumor cells. This review article provides a comprehensive overview of the current understanding of miR-136-5p in different sorts of human cancers: genital tumors, head and neck tumors, tumors from the digestive and urinary systems, skin cancers, neurologic tumors, pulmonary neoplasms and other cancers by discussing its molecular mechanisms, functional roles, and impact in chemotherapies. In conclusion, miR-136-5p could be a promising new biomarker and potential clinical therapeutic target.

Extracellular vesicle biomarkers in circulation for colorectal cancer detection: a systematic review and meta-analysis

We provided an overview which evaluated the diagnostic performance of circulation EV biomarkers for CRC from PubMed, Medline, and Web of Science until 21 August 2022.Weidentified 48 studies that involved 7727 participants and evaluated 162 plasma/serum individual EV biomarkers including 117 RNAs and 45 proteins, as well as 45 EV biomarker panels for CRC detection. 12 studies evaluated the diagnostic performance of EV biomarkers for early CRC. The summarized sensitivity, specificity, and AUC value of individual EV RNAs and EV RNA panels were 76%, 75%, 0.87 and 82%, 79% and 0.90, respectively. Meanwhile, those of individual EV proteins and EV protein panels were 85%, 84%, 0.92 and 87%, 83%, 0.92, respectively. These results indicated that EV biomarker panels revealed superior diagnostic performance than the corresponding individual biomarkers. In early CRC, EV biomarkers showed available diagnostic value with the sensitivity, specificity, and AUC value of 80%, 75%, and 0.89.In subgroup analyses, EV miRNAs and LncRNAs held similar diagnostic value with the sensitivity, specificity and AUC value of 75%, 78%, 0.90 and 79%, 72%, 0.83, which was highly consistent with the whole EV RNAs. Significantly, the diagnostic values of EV miRNAs in plasma were marginally higher than those based on serum. In detail, the sensitivity, specificity, and AUC values were 79%, 81%, and 0.92 in plasma, as well as 74%, 77%, and 0.88 in serum, respectively. Therefore, circulation EV biomarkers could be considered as a promising biomarker for the early detection of CRC.

Mapping the function of MicroRNAs as a critical regulator of tumor-immune cell communication in breast cancer and potential treatment strategies

Among women, breast cancer ranks as the most prevalent form of cancer, and the presence of metastases significantly reduces prognosis and diminishes overall survival rates. Gaining insights into the biological mechanisms governing the conversion of cancer cells, their subsequent spread to other areas of the body, and the immune system's monitoring of tumor growth will contribute to the advancement of more efficient and targeted therapies. MicroRNAs (miRNAs) play a critical role in the interaction between tumor cells and immune cells, facilitating tumor cells' evasion of the immune system and promoting cancer progression. Additionally, miRNAs also influence metastasis formation, including the establishment of metastatic sites and the transformation of tumor cells into migratory phenotypes. Specifically, dysregulated expression of these genes has been associated with abnormal expression of oncogenes and tumor suppressor genes, thereby facilitating tumor development. This study aims to provide a concise overview of the significance and function of miRNAs in breast cancer, focusing on their involvement as tumor suppressors in the antitumor immune response and as oncogenes in metastasis formation. Furthermore, miRNAs hold tremendous potential as targets for gene therapy due to their ability to modulate specific pathways that can either promote or suppress carcinogenesis. This perspective highlights the latest strategies developed for miRNA-based therapies.

Quinazoline sulfonamide derivatives targeting MicroRNA-34a/MDM4/p53 apoptotic axis with radiosensitizing activity

Aim: New quinazoline benzenesulfonamide hybrids 4a-n were synthesized to determine their cytotoxicity and effect on the miR-34a/MDM4/p53 apoptotic pathway. Materials & methods: Cytotoxicity against hepatic, breast, lung and colon cancer cell lines was estimated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results: Compound 4d was the most potent against HepG2 and MCF-7 cancer cells, with potential apoptotic activity verified by a significant upregulation of miR-34a and p53 gene expressions. The apoptotic effect of 4d was further investigated and showed downregulation of miR-21, VEGF, STAT3 and MDM4 gene expression. Conclusion: The anticancer and apoptotic activities of 4d were enhanced post irradiation by a single dose of 8 Gy γ-radiation. Docking analysis demonstrated a valuable affinity of 4d toward VEGFR2 and MDM4 active sites.

Liquid Biomarkers in Prostate Cancer Diagnosis: Current Status and Emerging Prospects

Prostate cancer (PCa) is a major health concern that necessitates appropriate diagnostic approaches for timely intervention. This review critically evaluates the role of liquid biopsy techniques, focusing on blood- and urine-based biomarkers, in overcoming the limitations of conventional diagnostic methods. The 4Kscore test and Prostate Health Index have demonstrated efficacy in distinguishing PCa from benign conditions. Urinary biomarker tests such as PCa antigen 3, MyProstateScore, SelectMDx, and ExoDx Prostate IntelliScore test have revolutionized risk stratification and minimized unnecessary biopsies. Emerging biomarkers, including non-coding RNAs, circulating tumor DNA, and prostate-specific antigen (PSA) glycosylation, offer valuable insights into PCa biology, enabling personalized treatment strategies. Advancements in non-invasive liquid biomarkers for PCa diagnosis may facilitate the stratification of patients and avoid unnecessary biopsies, particularly when PSA is in the gray area of 4 to 10 ng/mL.

Phosphorylation of AGO2 by TBK1 Promotes the Formation of Oncogenic miRISC in NSCLC

Non-small-cell lung cancer (NSCLC) is a highly lethal tumor that often develops resistance to targeted therapy. It is shown that Tank-binding kinase 1 (TBK1) phosphorylates AGO2 at S417 (pS417-AGO2), which promotes NSCLC progression by increasing the formation of microRNA-induced silencing complex (miRISC). High levels of pS417-AGO2 in clinical NSCLC specimens are positively associated with poor prognosis. Interestingly, the treatment with EGFR inhibitor Gefitinib can significantly induce pS417-AGO2, thereby increasing the formation and activity of oncogenic miRISC, which may contribute to NSCLC resistance to Gefitinib. Based on these, two therapeutic strategies is developed. One is jointly to antagonize multiple oncogenic miRNAs highly expressed in NSCLC and use TBK1 inhibitor Amlexanox reducing the formation of oncogenic miRISC. Another approach is to combine Gefitinib with Amlexanox to inhibit the progression of Gefitinib-resistant NSCLC. This findings reveal a novel mechanism of oncogenic miRISC regulation by TBK1-mediated pS417-AGO2 and suggest potential therapeutic approaches for NSCLC.

Genomic and epigenetic characterization of the arsenic-induced oncogenic microRNA-21

As one of the first identified oncogenic microRNAs, the precise details concerning the transcriptional regulation and function of microRNA-21 (miR-21) are still not completely established. The miR-21 gene is situated on chromosome 17q23.2, positioned at the 3'-UTR of the gene that encodes vacuole membrane protein-1 (VMP1). In this current study, we presented evidence indicating that miR-21 possesses its own gene promoter, which can be found in the intron 10 of the VMP1 gene. Chromatin immunoprecipitation followed by global DNA sequencing (ChIP-seq) revealed the presence of a broad H3K4me3 peak spanning the entire gene body of the primary miR-21 and the existence of super-enhancer clusters in the close proximity to both the miR-21 gene promoter and the transcription termination site in arsenic (As3+)-induced cancer stem-like cells (CSCs) and human induced pluripotent stem cells (hiPSCs). In non-transformed human bronchial epithelial cells (BEAS-2B), As3+ treatment enhanced Nrf2 binding to both the host gene VMP1 of miR-21 and the miR-21 gene. Knockout of Nrf2 inhibited both the basal and As3+-induced expressions of miR-21. Furthermore, the As3+-enhanced Nrf2 peaks in ChIP-seq fully overlap with these super-enhancers enriched with H3K4me1 and H3K27ac in the miR-21 gene, suggesting that Nrf2 may coordinate with other transcription factors through the super-enhancers to regulate the expression of miR-21 in cellular response to As3+. These findings demonstrate the unique genetic and epigenetic characteristics of miR-21 and may provide insights into understanding the novel mechanisms linking environmental As3+ exposure and human cancers.

The roles of lncRNAs and miRNAs in pancreatic cancer: a focus on cancer development and progression and their roles as potential biomarkers

Pancreatic ductal adenocarcinoma (PDAC) is among the most penetrative malignancies affecting humans, with mounting incidence prevalence worldwide. This cancer is usually not diagnosed in the early stages. There is also no effective therapy against PDAC, and most patients have chemo-resistance. The combination of these factors causes PDAC to have a poor prognosis, and often patients do not live longer than six months. Because of the failure of conventional therapies, the identification of key biomarkers is crucial in the early diagnosis, treatment, and prognosis of pancreatic cancer. 65% of the human genome encodes ncRNAs. There are different types of ncRNAs that are classified based on their sequence lengths and functions. They play a vital role in replication, transcription, translation, and epigenetic regulation. They also participate in some cellular processes, such as proliferation, differentiation, metabolism, and apoptosis. The roles of ncRNAs as tumor suppressors or oncogenes in the growth of tumors in a variety of tissues, including the pancreas, have been demonstrated in several studies. This study discusses the key roles of some lncRNAs and miRNAs in the growth and advancement of pancreatic carcinoma. Because they are involved not only in the premature identification, chemo-resistance and prognostication, also their roles as potential biomarkers for better management of PDAC patients.

Targeting MicroRNAs with Small Molecules

MicroRNAs (miRs) have been implicated in numerous diseases, presenting an attractive target for the development of novel therapeutics. The various regulatory roles of miRs in cellular processes underscore the need for precise strategies. Recent advances in RNA research offer hope by enabling the identification of small molecules capable of selectively targeting specific disease-associated miRs. This understanding paves the way for developing small molecules that can modulate the activity of disease-associated miRs. Herein, we discuss the progress made in the field of drug discovery processes, transforming the landscape of miR-targeted therapeutics by small molecules. By leveraging various approaches, researchers can systematically identify compounds to modulate miR function, providing a more potent intervention either by inhibiting or degrading miRs. The implementation of these multidisciplinary approaches bears the potential to revolutionize treatments for diverse diseases, signifying a significant stride towards the targeting of miRs by precision medicine.

Selective miR-21 detection technology based on photocrosslinkable artificial nucleic acid-modified magnetic particles and hybridization chain reaction

Recently, microRNA (miRNA) detection in blood has attracted attention as a new early detection technology for cancer. The extraction of target miRNA is a necessary preliminary step for detection; however, currently, most extraction methods extract all RNA from the blood, which limits the detection selectivity. Therefore, a method for the selective extraction and detection of target miRNA from blood is very important. In this study, we utilized photocrosslinkable artificial nucleic acids and the hybridization chain reaction (HCR) in an attempt to improve upon the current standard method RT-qPCR, which is hampered by problems with primer design and enzymatic amplification. By introducing photocrosslinkable artificial nucleic acids to oligonucleotide probes modified with magnetic particles with a sequence complementary to that of the target miRNA and irradiating them with light, covalent bonds were formed between the target miRNA and the oligonucleotide probes. These tight covalent bonds enabled the capture of miRNA in blood, and intensive washing ensured that only the target miRNA were extracted. After extraction, two types of DNA (H1 and H2) modified with fluorescent dyes were added and the fluorescence signals were amplified by the HCR in the presence of the target miRNA bound to the photocrosslinkable artificial nucleic acids, allowing for isothermal and enzyme-free miRNA detection. The novel method is suitable for selective miRNA detection in real blood samples. Because the reaction proceeds isothermally and no specialized equipment is used for washing, this detection technology is simple and selective and suitable for application to point-of-care technology using microfluidic devices.

Global scientific trends in research of epigenetic response to exercise: A bibliometric analysis

The purpose of this work is to comprehensively understand the adaptive response of multiple epigenetic modifications on gene expression changes driven by exercise. Here, we retrieved literatures from publications in the PubMed and Web of Science Core Collection databases up to and including October 15, 2023. After screening with the exclusion criteria, 1910 publications were selected in total, comprising 1399 articles and 511 reviews. Specifically, a total of 512, 224, and 772 publications is involved in DNA methylation, histone modification, and noncoding RNAs, respectively. The correlations between publication number, authors, institutions, countries, references, and the characteristics of hotspots were explored by CiteSpace. Here, the USA (621 publications) ranked the world's most-influential countries, the University of California System (68 publications) was the most productive, and Tiago Fernandes (14 publications) had the most-published publications. A comprehensive keyword analysis revealed that cardiovascular disease, cancer, skeletal muscle development, and metabolic syndrome, and are the research hotspots. The detailed impact of exercise was further discussed in different aspects of these three categories of epigenetic modifications. Detailed analysis of epigenetic modifications in response to exercise, including DNA methylation, histone modification, and changes in noncoding RNAs, will offer valuable information to help researchers understand hotspots and emerging trends.

CMC: Cancer miRNA Census - a list of cancer-related miRNA genes

A growing body of evidence indicates an important role of miRNAs in cancer; however, there is no definitive, convenient-to-use list of cancer-related miRNAs or miRNA genes that may serve as a reference for analyses of miRNAs in cancer. To this end, we created a list of 165 cancer-related miRNA genes called the Cancer miRNA Census (CMC). The list is based on a score, built on various types of functional and genetic evidence for the role of particular miRNAs in cancer, e.g. miRNA-cancer associations reported in databases, associations of miRNAs with cancer hallmarks, or signals of positive selection of genetic alterations in cancer. The presence of well-recognized cancer-related miRNA genes, such as MIR21, MIR155, MIR15A, MIR17 or MIRLET7s, at the top of the CMC ranking directly confirms the accuracy and robustness of the list. Additionally, to verify and indicate the reliability of CMC, we performed a validation of criteria used to build CMC, comparison of CMC with various cancer data (publications and databases), and enrichment analyses of biological pathways and processes such as Gene Ontology or DisGeNET. All validation steps showed a strong association of CMC with cancer/cancer-related processes confirming its usefulness as a reference list of miRNA genes associated with cancer.

Over-expression of mir-181a-3p in serum of breast cancer patients as diagnostic biomarker

BACKGROUND

Recently, the significance of epigenetics, particularly in breast cancer (BC), has become increasingly recognized. MicroRNAs (miRNAs), as an epigenetic factor, are offering valuable insights into various aspects of BC, such as its origins and clinical features. Therefore, studying the disruption of specific miRNAs through microarray and RNA-seq techniques is considered useful.

METHODS AND MATERIALS

We analyzed two microarray datasets (GSE106817 and GSE113486) in order to discover dysregulated miRNAs in the serum of BC patients. Subsequently, RNA-seq analysis was employed on the TCGA data. Two miRNAs, mir-450a-5p and mir-181a-3p, as novel miRNAs in BC studies, were selected for assessment in the serum of 100 BC patients versus 100 healthy female participants. The quantities of the miRNAs described above were determined through the utilization of RT-qPCR. Furthermore, ROC curve assessments were conducted for each individual miRNA. Next, an assessment was conducted to determine the prognostic significance of these miRNAs.

CONCLUSIONS

In summary, the utilization of microarray and RNA-seq analysis techniques has demonstrated that mir-450a-5p and mir-181a-3p exhibit elevated expression levels in the serum of BC patients. However, it is noteworthy that only mir-181a-3p displayed clinical dysregulation, as confirmed by RT-PCR findings. These miRNAs have been found to play a crucial role in modulating essential cellular processes and biological functions that contribute to cancer development. Furthermore, noteworthy outcomes have been observed for mir-181a-3p in relation to diagnostic and prognostic clinical characteristics.

Integrative Metabolomic Analysis of Serum and Selected Serum Exosomal microRNA in Metastatic Castration-Resistant Prostate Cancer

Metastatic castration-resistant prostate cancer (mCRPC) remains a lethal disease due to the absence of effective therapies. A more comprehensive understanding of molecular events, encompassing the dysregulation of microRNAs (miRs) and metabolic reprogramming, holds the potential to unveil precise mechanisms underlying mCRPC. This study aims to assess the expression of selected serum exosomal miRs (miR-15a, miR-16, miR-19a-3p, miR-21, and miR-141a-3p) alongside serum metabolomic profiling and their correlation in patients with mCRPC and benign prostate hyperplasia (BPH). Blood serum samples from mCRPC patients (n = 51) and BPH patients (n = 48) underwent metabolome analysis through 1H-NMR spectroscopy. The expression levels of serum exosomal miRs in mCRPC and BPH patients were evaluated using a quantitative real-time polymerase chain reaction (qRT-PCR). The 1H-NMR metabolomics analysis revealed significant alterations in lactate, acetate, citrate, 3-hydroxybutyrate, and branched-chain amino acids (BCAAs, including valine, leucine, and isoleucine) in mCRPC patients compared to BPH patients. MiR-15a, miR-16, miR-19a-3p, and miR-21 exhibited a downregulation of more than twofold in the mCRPC group. Significant correlations were predominantly observed between lactate, citrate, acetate, and miR-15a, miR-16, miR-19a-3p, and miR-21. The importance of integrating metabolome analysis of serum with selected serum exosomal miRs in mCRPC patients has been confirmed, suggesting their potential utility for distinguishing of mCRPC from BPH.

Dynamic Role of miRNAs in Salivary Gland Carcinomas: From Biomarkers to Therapeutic Targets

BACKGROUND

Salivary gland carcinomas (SGCs) are a rare group of malignant neoplasms of the head and neck region. MicroRNAs (miRNAs) are a class of small non-coding RNAs that have been associated with the control biological process and oncogenic mechanism by the regulation of gene expression at the post-transcriptional level. Recent evidence has suggested that miRNA expression may play a role in the tumorigenesis and carcinogenesis process in SGCs.

METHODS

This review provides a comprehensive literature review of the role of miRNAs expression in SGCs focusing on the diagnostic, prognostic, and therapeutic applications.

RESULTS

In this review, numerous dysregulated miRNAs have demonstrated an oncogenic and suppressor role in SGCs.

CONCLUSION

In the future, these miRNAs may eventually constitute useful diagnostic and prognostic biomarkers that may lead to a better understanding of SGCs oncogenesis. Additionally, the development of therapeutic agents based on miRNAs may be a promising target in SGC treatment.

Circulating serum miR-362-3p and miR-6721-5p as potential biomarkers for classification patients with adult-type diffuse glioma

According to the fifth edition of the WHO Classification of Tumours of the Central Nervous System (CNS) published in 2021, grade 4 gliomas classification includes IDH-mutant astrocytomas and wild-type IDH glioblastomas. Unfortunately, despite precision oncology development, the prognosis for patients with grade 4 glioma remains poor, indicating an urgent need for better diagnostic and therapeutic strategies. Circulating miRNAs besides being important regulators of cancer development could serve as promising diagnostic biomarkers for patients with grade 4 glioma. Here, we propose a two-miRNA miR-362-3p and miR-6721-5p screening signature for serum for non-invasive classification of identified glioma cases into the highest-grade 4 and lower-grade gliomas. A total of 102 samples were included in this study, comprising 78 grade 4 glioma cases and 24 grade 2-3 glioma subjects. Using the NanoString platform, seven miRNAs were identified as differentially expressed (DE), which was subsequently confirmed via RT-qPCR analysis. Next, numerous combinations of DE miRNAs were employed to develop classification models. The dual panel of miR-362-3p and miR-6721-5p displayed the highest diagnostic value to differentiate grade 4 patients and lower grade cases with an AUC of 0.867. Additionally, this signature also had a high AUC = 0.854 in the verification cohorts by RT-qPCR and an AUC = 0.842 using external data from the GEO public database. The functional annotation analyses of predicted DE miRNA target genes showed their primary involvement in the STAT3 and HIF-1 signalling pathways and the signalling pathway of pluripotency of stem cells and glioblastoma-related pathways. For additional exploration of miRNA expression patterns correlated with glioma, we performed the Weighted Gene-Co Expression Network Analysis (WGCNA). We showed that the modules most associated with glioma grade contained as many as six DE miRNAs. In conclusion, this study presents the first evidence of serum miRNA expression profiling in adult-type diffuse glioma using a classification based on the WHO 2021 guidelines. We expect that the discovered dual miR-362-3p and miR-6721-5p signatures have the potential to be utilised for grading gliomas in clinical applications.

Let-7b-5p promotes triptolide-induced growth-inhibiting effects in glioma by targeting IGF1R

Glioma is one of the most common malignancies of the central nervous system. The therapeutic effect has not been satisfactory despite advances in comprehensive treatment techniques. Our previous studies have found that triptolide inhibits glioma proliferation through the ROS/JNK pathway, but in-depth mechanisms need to be explored. Recent studies have confirmed that miRNAs may function as tumor suppressor genes or oncogenes and be involved in cancer development and progression. In this study, we found that let-7b-5p expression levels closely correlated with WHO grades and overall survival in patients in tumor glioma-CGGA-mRNAseq-325, and the upregulation of let-7b-5p can inhibit the proliferation and induce apoptosis of glioma cells. Functionally, upregulation of let-7b-5p increased the inhibitory effect on cell viability and colony formation caused by triptolide and promoted the apoptosis rate of triptolide-treated U251 cells. Conversely, downregulation of let-7b-5p had the opposite effect, indicating that let-7b-5p is a tumor suppressor miRNA in glioma cells. Moreover, target prediction, luciferase reporter assays and functional experiments revealed that IGF1R was a direct target of let-7b-5p. In addition, upregulation of IGF1R reversed the triptolide-regulated inhibition of cell viability but promoted glioma cell apoptosis and activated the ROS/JNK signaling pathway induced by triptolide. The results obtained in vivo experiments substantiated those from the in vitro experiments. In summary, the current study provides evidence that triptolide inhibits the growth of glioma cells by regulating the let-7b-5p-IGF1R-ROS/JNK axis in vitro and in vivo. These findings may provide new ideas and potential targets for molecularly targeted therapies for comprehensive glioma treatment.

Spatially Exploring RNA Biology in Archival Formalin-Fixed Paraffin-Embedded Tissues

Spatial transcriptomics has emerged as a powerful tool for dissecting spatial cellular heterogeneity but as of today is largely limited to gene expression analysis. Yet, the life of RNA molecules is multifaceted and dynamic, requiring spatial profiling of different RNA species throughout the life cycle to delve into the intricate RNA biology in complex tissues. Human disease-relevant tissues are commonly preserved as formalin-fixed and paraffin-embedded (FFPE) blocks, representing an important resource for human tissue specimens. The capability to spatially explore RNA biology in FFPE tissues holds transformative potential for human biology research and clinical histopathology. Here, we present Patho-DBiT combining in situ polyadenylation and deterministic barcoding for spatial full coverage transcriptome sequencing, tailored for probing the diverse landscape of RNA species even in clinically archived FFPE samples. It permits spatial co-profiling of gene expression and RNA processing, unveiling region-specific splicing isoforms, and high-sensitivity transcriptomic mapping of clinical tumor FFPE tissues stored for five years. Furthermore, genome-wide single nucleotide RNA variants can be captured to distinguish different malignant clones from non-malignant cells in human lymphomas. Patho-DBiT also maps microRNA-mRNA regulatory networks and RNA splicing dynamics, decoding their roles in spatial tumorigenesis trajectory. High resolution Patho-DBiT at the cellular level reveals a spatial neighborhood and traces the spatiotemporal kinetics driving tumor progression. Patho-DBiT stands poised as a valuable platform to unravel rich RNA biology in FFPE tissues to study human tissue biology and aid in clinical pathology evaluation.

MicroRNA-21's role in PTEN suppression and PI3K/AKT activation: Implications for cancer biology

MicroRNA-21 (miR-21) was recognized as a key figure in the intricate web of tumor biology, with a prominent role in regulating the PTEN tumor suppressor gene and the PI3K/AKT cascade. This review elucidates the multifaceted interactions between miR-21, PTEN, and the PI3K/AKT signaling, shedding light on their profound implications in cancer initiation, progression, and therapeutic strategies. The core of this review delves into the mechanical intricacies of miR-21-mediated PTEN suppression and its consequent impact on PI3K/AKT pathway activation. It explores how miR-21, as an oncogenic miRNA, targets PTEN directly or indirectly, resulting in uncontrolled activation of PI3K/AKT, fostering cancerous cell survival, proliferation, and evasion of apoptosis. Furthermore, the abstract emphasizes the clinical relevance of these molecular interactions, discussing their implications in various cancer types, prognostic significance, and potential as therapeutic targets. The review provides insights into ongoing research efforts to develop miR-21 inhibitors and strategies to restore PTEN function, offering new avenues for cancer treatment. This article illuminates the critical function of miR-21 in PTEN suppression and PI3K/AKT activation, offering profound insights into its implications for cancer biology and the potential for targeted interventions.

Regulating pri/pre-microRNA up/down expressed in cancer proliferation, angiogenesis and metastasis using selected potent triterpenoids

MicroRNAs (miRNAs) play a crucial role in cancer progression by selectively inducing translational degradation of messenger RNA (mRNA) via sequence-specific interactions with the 3'-untranslated region (3'-UTR). The potential targeting of miRNA has been recognized as a significant avenue for investigating the biological progression of diverse cancer types. Consequently, targeting of pri-miRNA and pre-miRNA by phytochemicals emerges as a viable strategy in the realm of anticancer therapies. Among phytochemicals, triterpenoids have garnered significant recognition for their chemotherapeutic and chemopreventive capabilities in combating multiple cancers. To date, there is a dearth of literature about the molecular interactions between triterpenoids and miRNAs. The primary objective of this investigation is to discern the potential triterpenoids that can function as modulators for specific miRNAs, namely pri-miRNA-19b-2, pre-miR21, microRNA 20b, pri-miRNA-208a, pri-miRNA-378a, pri-miRNA-320b-2, and pri-miRNA-300, achieved through the use of in silico investigations. The study primarily focused on performing drug-likeness, computer-aided toxicity, and pharmacokinetic prediction studies for triterpenoids. Furthermore, molecular docking and simulation techniques were employed to investigate these compounds. The triterpenoids studied were shown to have drug-likeness characteristics, although asiatic acid, lupeol, and pristimerin were able to pass all toxicity tests. Among the triterpenoids that underwent docking, pristimerin had a significant binding energy of -10.9 kcal/mol during its interaction with pri-miR-378a. The stable interaction between the pristimerin and miRNA complex was demonstrated by molecular dynamics simulation. As a result, pristimerin has the potential to act as a modulator of carcinogenic miRNAs, making it a promising candidate for cancer prevention and treatment due to its tailored modulation of miRNA activity.

Association of microRNA-21 expression with breast cancer subtypes and its potential as an early biomarker

Breast cancer has become the most diagnosed cancer worldwide in 2020 with high morbidity and mortality rates. The alarming increase in breast cancer incidence has sprung many researchers to focus on developing novel screening tests to identify early breast cancer which will allow clinicians to provide timely and effective treatments. With much evidence supporting the notion that the deregulation of miRNAs (a class of non-coding RNA) greatly contributes to cancer initiation and progression, the promising role of miRNAs as cancer biomarkers is gaining traction in the research world. Among the upregulated miRNAs identified in breast carcinogenesis, miR-21 was shown to be significantly expressed in breast cancer tissues and bodily fluids of breast cancer patients. Therein, this review paper aims to provide an overview of breast cancer, the role and significance of miR-21 in breast cancer pathogenesis, and its potential as a breast cancer biomarker. The paper also discusses the current types of tumor biomarkers and their limitations, the presence of miR-21 in extracellular vesicles and plasma, screening methods available for miRNA detection along with some challenges faced in developing diagnostic miR-21 testing for breast cancer to provide readers with a comprehensive outlook based on using miR-21 in clinical settings.

The regulatory mechanisms of oncomiRs in cancer

Cancer development is a complex process that primarily results from the combination of genetic alterations and the dysregulation of major signalling pathways due to interference with the epigenetic machinery. As major epigenetic regulators, miRNAs are central players in the control of many key tumour development factors. These miRNAs have been classified as oncogenic miRNAs (oncomiRs) when they target tumour suppressor genes and tumour suppressor miRNAs (TS miRNAs) when they inhibit oncogene protein expression. Most of the mechanisms that modulate oncomiR expression are linked to transcriptional or posttranscriptional regulation. However, non-transcriptional processes, such as gene amplification, have been described as alternative processes that are responsible for increasing oncomiR expression. The current review summarises the different mechanisms controlling the upregulation of oncomiR expression in cancer cells and the tumour microenvironment (TME). Detailed knowledge of the mechanism underlying the regulation of oncomiR expression in cancer may pave the way for understanding the critical role of oncomiRs in cancer development and progression.

microRNAs and their therapeutic strategy in phase I and phase II clinical trials

miRNAs play a crucial therapeutic role in diseases such as cancer, diabetes and viral infections, with around 1900 identified in the human genome. Some have progressed to clinical trials, and miRNA mimics and miRNA inhibitors are pivotal therapeutic molecules undergoing evaluation. The review delves into various miRNA-associated clinical trials, emphasizing their precision in targeting specific genes, modulating disease pathways and diagnostic potential. This underscores the importance of miRNA therapy, foreseeing innovations in precision medicine techniques for diverse diseases. The future envisions improved delivery systems addressing challenges like immunogenicity and digestion, while a comprehensive miRNA-based omics database could guide the development of tailored antisense miRNAs, further advancing precision medicine strategies.

Current evidence regarding the cellular mechanisms associated with cancer progression due to cardiovascular diseases

Several large cohort studies in cardiovascular disease (CVD) patients have shown an increased incidence of cancer. Previous studies in a myocardial infarction (MI) mouse model reported increased colon, breast, and lung cancer growth. The potential mechanisms could be due to secreted cardiokines and micro-RNAs from pathological hearts and immune cell reprogramming. A study in a MI-induced heart failure (HF) mouse demonstrated an increase in cardiac expression of SerpinA3, resulting in an enhanced proliferation of colon cancer cells. In MI-induced HF mice with lung cancer, the attenuation of tumor sensitivity to ferroptosis via the secretion of miR-22-3p from cardiomyocytes was demonstrated. In MI mice with breast cancer, immune cell reprogramming toward the immunosuppressive state was shown. However, a study in mice with renal cancer reported no impact of MI on tumor growth. In addition to MI, cardiac hypertrophy was shown to promote the growth of breast and lung cancer. The cardiokine potentially involved, periostin, was increased in the cardiac tissue and serum of a cardiac hypertrophy model, and was reported to increase breast cancer cell proliferation. Since the concept that CVD could influence the initiation and progression of several types of cancer is quite new and challenging regarding future therapeutic and preventive strategies, further studies are needed to elucidate the potential underlying mechanisms which will enable more effective risk stratification and development of potential therapeutic interventions to prevent cancer in CVD patients.

The crosstalk between miRNAs and signaling pathways in human cancers: Potential therapeutic implications

MicroRNAs (miRNAs) are increasingly recognized as central players in the regulation of eukaryotic physiological processes. These small double stranded RNA molecules have emerged as pivotal regulators in the intricate network of cellular signaling pathways, playing significant roles in the development and progression of human cancers. The central theme in miRNA-mediated regulation of signaling pathways involves their ability to target and modulate the expression of pathway components. Aberrant expression of miRNAs can either promote or suppress key signaling events, influencing critical cellular processes such as proliferation, apoptosis, angiogenesis, and metastasis. For example, oncogenic miRNAs often promote cancer progression by targeting tumor suppressors or negative regulators of signaling pathways, thereby enhancing pathway activity. Conversely, tumor-suppressive miRNAs frequently inhibit oncogenic signaling by targeting key components within these pathways. This complex regulatory crosstalk underscores the significance of miRNAs as central players in shaping the signaling landscape of cancer cells. Furthermore, the therapeutic implications of targeting miRNAs in cancer are substantial. miRNAs can be manipulated to restore normal signaling pathway activity, offering a potential avenue for precision medicine. The development of miRNA-based therapeutics, including synthetic miRNA mimics and miRNA inhibitors, has shown promise in preclinical and clinical studies. These strategies aim to either enhance the activity of tumor-suppressive miRNAs or inhibit the function of oncogenic miRNAs, thereby restoring balanced signaling and impeding cancer progression. In conclusion, the crosstalk between miRNAs and signaling pathways in human cancers is a dynamic and influential aspect of cancer biology. Understanding this interplay provides valuable insights into cancer development and progression. Harnessing the therapeutic potential of miRNAs as regulators of signaling pathways opens up exciting opportunities for the development of innovative cancer treatments with the potential to improve patient outcomes. In this chapter, we provide an overview of the crosstalk between miRNAs and signaling pathways in the context of cancer and highlight the potential therapeutic implications of targeting this regulatory interplay.

A novel therapeutic strategy: the significance of exosomal miRNAs in acute myeloid leukemia

Acute myeloid leukemia (AML) is a fast-growing blood cancer that interferes with the normal growth of blood cells in the bone marrow and blood. It is characterized by its unpredictable outlook and high death rate. The main treatment for AML is chemotherapy, but this often results in drug resistance and the possibility of the disease returning. For this reason, new biomarkers are necessary to diagnose, predict, and treat this disease. Research has demonstrated that cells responsible for AML release exosomes that interact with the disease's microenvironment. These exosomes have significant roles in promoting leukemia growth, suppressing normal hematopoiesis, facilitating angiogenesis, and contributing to drug resistance in AML. Further investigations have shown that these exosomes contain miRNAs, which are transferred to target cells and have functional roles. Biomarkers are utilized to assess various aspects of tumor cell behavior, including proliferation, apoptosis, angiogenesis, changes in the microenvironment, transfer of drug resistance, and stability in serum and blood plasma. In this research, we showed that exosomal miRNAs and exosomes have the potential to be used as indicators for detecting various phases of AML and can aid in its medical treatment. Furthermore, they can be specifically targeted for therapeutic purposes in addressing this condition.

CVD phenotyping in oncologic disorders: cardio-miRNAs as a potential target to improve individual outcomes in revers cardio-oncology

With the increase of aging population and prevalence of obesity, the incidence of cardiovascular disease (CVD) and cancer has also presented an increasing tendency. These two different diseases, which share some common risk factors. Relevant studies in the field of reversing Cardio-Oncology have shown that the phenotype of CVD has a significant adverse effect on tumor prognosis, which is mainly manifested by a positive correlation between CVD and malignant progression of concomitant tumors. This distal crosstalk and the link between different diseases makes us aware of the importance of diagnosis, prediction, management and personalized treatment of systemic diseases. The circulatory system bridges the interaction between CVD and cancer, which suggests that we need to fully consider the systemic and holistic characteristics of these two diseases in the process of clinical treatment. The circulating exosome-miRNAs has been intrinsically associated with CVD -related regulation, which has become one of the focuses on clinical and basic research (as biomarker). The changes in the expression profiles of cardiovascular disease-associated miRNAs (Cardio-miRNAs) may adversely affect concomitant tumors. In this article, we sorted and screened CVD and tumor-related miRNA data based on literature, then summarized their commonalities and characteristics (several important pathways), and further discussed the conclusions of Cardio-Oncology related experimental studies. We take a holistic approach to considering CVD as a risk factor for tumor malignancy, which provides an in-depth analysis of the various regulatory mechanisms or pathways involved in the dual attribute miRNAs (Cardio-/Onco-miRNAs). These mechanisms will be key to revealing the systemic effects of CVD on tumors and highlight the holistic nature of different diseases. Therefore, the Cardio-miRNAs should be given great attention from researchers in the field of CVD and tumors, which might become new targets for tumor treatment. Meanwhile, based on the principles of precision medicine (such as the predictive preventive personalized medicine, 3PM) and reverse Cardio-oncology to better improve individual outcomes, we should consider developing personalized medicine and systemic therapy for cancer from the perspective of protecting cardiovascular function.

Liquid biopsy evaluation of circulating tumor DNA, miRNAs, and cytokines in meningioma patients

Introduction

Liquid biopsy is a non-invasive method used to detect cancer and monitor treatment responses by analyzing blood or other bodily fluids for cancer biomarkers. Meningiomas are the most common primary central nervous system tumors, and biomarkers play a crucial role in their diagnosis, prognosis, and treatment monitoring. The World Health Organization (WHO) classifies meningiomas based on tumor grades and molecular alterations in genes such as in NF2, AKT1, TRAF7, SMO, PIK3CA, KLF4, SMARCE1, BAP1, H3K27me3, TERT promoter, and CDKN2A/B. Liquid biopsy, specifically cell-free DNA (cfDNA) analysis, has shown potential for monitoring meningiomas as it can detect ctDNA release in the blood, unaffected by the blood-brain barrier. MicroRNAs (miRNAs) have also been found to be deregulated in various cancers, including meningiomas, presenting potential as diagnostic biomarkers. Additionally, studying cytokines in the tumor microenvironment may aid in establishing prognostic or diagnostic panels for meningiomas.

Methods

In the present study we analyzed the DNA coming from both the plasma and tumor samples, in addition to analyze miRNA-21 and cytokines in the plasma of 28 meningioma patients.

Discussion and Conclusion

Our findings indicate that the detection of ctDNA in the plasma of meningioma patients is feasible. However, it's important to note that certain challenges persist when comparing plasma DNA analysis to that of tumor tissues. In our study, we observed a paired identification of mutations in only one patient, highlighting the complexities involved. Furthermore, we successfully identified miR-21 and cytokines in the plasma samples. Notably, our analysis of Interleukin 6 (IL-6) unveiled higher expression in the clear cell subtype compared to the other types. Despite the ongoing research, the clinical implementation of liquid biopsy in meningiomas remains somewhat limited. Nevertheless, our promising results underscore the need for further investigation.

A universal orthogonal imaging platform for living-cell RNA detection using fluorogenic RNA aptamers

MicroRNAs (miRNAs) are crucial regulators of gene expression at the post-transcriptional level, offering valuable insights into disease mechanisms and prospects for targeted therapeutic interventions. Herein, we present a class of miRNA-induced light-up RNA sensors (miLS) that are founded on the toehold mediated principle and employ the fluorogenic RNA aptamers Pepper and Squash as imaging modules. By incorporating a sensor switch to disrupt the stabilizing stem of these aptamers, our design offers enhanced flexibility and convertibility for different target miRNAs and aptamers. These sensors detect multiple miRNA targets (miR-21 and miR-122) with detection limits of 0.48 and 0.2 nM, respectively, while achieving a robust signal-to-noise ratio of up to 44 times. Capitalizing on the distinct fluorescence imaging channels afforded by Pepper-HBC620 (red) and Squash-DFHBI-1T (green), we establish an orthogonal miRNA activation imaging platform, enabling the simultaneous visualization of different intracellular miRNAs in living cells. Our dual-color orthogonal miLS imaging platform provides a powerful tool for sequence-specific miRNA imaging in different cells, opening up new avenues for studying the intricate functions of RNA in living cells.

METTL3 promotes non-small-cell lung cancer growth and metastasis by inhibiting FDX1 through copper death-associated pri-miR-21-5p maturation

Objective: We probed into the significance of METTL3 in the maturation process of pri-miR-21-5p. We specifically investigated its impact on the regulation of FDX1 and its involvement in the progression of non-small-cell lung cancer (NSCLC). Methods: The Cancer Genome Atlas (TCGA) identified NSCLC factors. Methylation-specific PCR (MSP), clonogenic tests and flow cytometry analyzed cells. Methylated RNA immunoprecipitation (Me-RIP) and dual-luciferase studied miR-21-5p/FDX1. Mice xenografts showed METTL3's tumorigenic effect. Results: METTL3, with high expression but low methylation in NSCLC, influenced cell behaviors. Its suppression reduced oncogenic properties. METTL3 enhanced miR-21-5p maturation, targeting FDX1 and boosting NSCLC tumorigenicity in mice. Conclusion: METTL3 may promote NSCLC development by facilitating pri-miR-21-5p maturation, upregulating miR-21-5p and targeting inhibition of FDX1.

Practical magnetic bead-based capillary electrophoresis with laser-induced fluorescence for detecting endogenous miRNA in plasma

MicroRNAs (miRNAs) are small, non-coding RNAs crucial for gene regulation and implicated in various human diseases. Their potential as clinical prognostic and diagnostic biomarkers in biological fluids necessitates reliable detection methods. In this study, a combination of streptavidin-coupled magnetic beads and capillary electrophoresis with laser-induced fluorescence (CE-LIF) was used to extract and analyze plasma miRNAs. Specifically, miRNAs hybridized with a biotinylated fluorescent DNA probe were isolated from plasma using magnetic beads. These hybridized miRNAs were then directly injected into the CE-LIF system for analysis, eliminating the need for additional processing steps. Both the hybridization and bead-to-probe binding were executed concurrently, regulated by temperature and time. Through the optimization of magnetic bead extraction and CE-LIF conditions, we developed a highly sensitive assay for miR-21 quantification in plasma. The assay displayed remarkable linearity (R2 = 0.9975) within a 0.1-5 pM range and exhibited favorable precision (0.22-1.26 %) and accuracy (98.31-111.19 %). Importantly, we successfully detected endogenous miR-21 in plasma samples from both a lung cancer patient and healthy adults, revealing a 1.7-fold overexpression of miR-21 in lung cancer plasma relative to normal samples. Our findings suggest that this developed system offers a simple and sensitive approach for detecting endogenous miRNAs in plasma, showing its potential utility in disease diagnostics. To our knowledge, this is the first study to utilize CE-LIF for plasma miRNA detection.

miRNA Expression Profiling in Human Breast Cancer Diagnostics and Therapy

Breast cancer is one of the most commonly diagnosed cancer types worldwide. Regarding molecular characteristics and classification, it is a heterogeneous disease, which makes it more challenging to diagnose. As is commonly known, early detection plays a pivotal role in decreasing mortality and providing a better prognosis for all patients. Different treatment strategies can be adjusted based on tumor progression and molecular characteristics, including personalized therapies. However, dealing with resistance to drugs and recurrence is a challenge. The therapeutic options are limited and can still lead to poor clinical outcomes. This review aims to shed light on the current perspective on the role of miRNAs in breast cancer diagnostics, characteristics, and prognosis. We discuss the potential role of selected non-coding RNAs most commonly associated with breast cancer. These include miR-21, miR-106a, miR-155, miR-141, let-7c, miR-335, miR-126, miR-199a, miR-101, and miR-9, which are perceived as potential biomarkers in breast cancer prognosis, diagnostics, and treatment response monitoring. As miRNAs differ in expression levels in different types of cancer, they may provide novel cancer therapy strategies. However, some limitations regarding dynamic alterations, tissue-specific profiles, and detection methods must also be raised.

Identification of serum miR-1246 and miR-150-5p as novel diagnostic biomarkers for high-grade serous ovarian cancer

Epithelial ovarian cancer (EOC) is one of the leading cancers in women, with high-grade serous ovarian cancer (HGSOC) being the most common and lethal subtype of this disease. A vast majority of HGSOC are diagnosed at the late stage of the disease when the treatment and total recovery chances are low. Thus, there is an urgent need for novel, more sensitive and specific methods for early and routine HGSOC clinical diagnosis. In this study, we performed miRNA expression profiling using the NanoString miRNA assay in 34 serum samples from patients with HGSOC and 36 healthy women. We identified 13 miRNAs that were differentially expressed (DE). For additional exploration of expression patterns correlated with HGSOC, we performed weighted gene co-expression network analysis (WGCNA). As a result, we showed that the module most correlated with tumour size, nodule and metastasis contained 8 DE miRNAs. The panel including miR-1246 and miR-150-5p was identified as a signature that could discriminate HGSOC patients with AUCs of 0.98 and 1 for the training and test sets, respectively. Furthermore, the above two-miRNA panel had an AUC = 0.946 in the verification cohorts of RT-qPCR data and an AUC = 0.895 using external data from the GEO public database. Thus, the model we developed has the potential to markedly improve the diagnosis of ovarian cancer.

Exosome-Hijacking Drug Delivery System with Branched Arginine Linker Effectively Deliver Antisense Oligonucleotides into Lung Adenocarcinoma Cells

Exosomes are a type of extracellular vesicles that contain diverse molecules and are present in our body fluids. They play a crucial role in transporting materials and transmitting signals between cells. Currently, there have been numerous reports on the use of exosomes in drug delivery systems (DDS). However, most existing methods for utilizing exosomes in DDS require the isolation and purification of exosomes, which raises concerns about yield and potential damage to the exosomes. Recently, we have developed a novel DDS called "ExomiR-Tracker" that harnesses exosomes without the need for isolation and purification. This system aims to deliver nucleic acid drugs effectively. ExomiR-Tracker consists of an anti-exosome antibody equipped with nona-D-arginines (9 mer) and nucleic acid drugs which have complementary sequence of target microRNA (anti-miR). In this study, we modified ExomiR-Tracker by incorporating branched nona-D-arginines (9 + 9 mer) molecules (referred to as Branch ExomiR-Tracker) and evaluated its efficacy in lung adenocarcinoma cells (A549 cells). The improved complex formation ability and enhanced cellular uptake of anti-miR, demonstrated by our findings, highlight the advantages of incorporating branched oligoarginine peptides into the ExomiR-Tracker platform. These results represent significant progress in revealing the effectiveness of Branch ExomiR-Tracker against adhesive cancer cells, which has not been shown to be effective with the conventional Linear ExomiR-Tracker.

miRNAs and exosomal miRNAs in lung cancer: New emerging players in tumor progression and therapy response

Non-coding RNAs have shown key roles in cancer and among them, short RNA molecules are known as microRNAs (miRNAs). These molecules have length less than 25 nucleotides and suppress translation and expression. The functional miRNAs are produced in cytoplasm. Lung cancer is a devastating disease that its mortality and morbidity have undergone an increase in recent years. Aggressive behavior leads to undesirable prognosis and tumors demonstrate abnormal proliferation and invasion. In the present review, miRNA functions in lung cancer is described. miRNAs reduce/increase proliferation and metastasis. They modulate cell death and proliferation. Overexpression of oncogenic miRNAs facilitates drug resistance and radio-resistance in lung cancer. Tumor microenvironment components including macrophages and cancer-associated fibroblasts demonstrate interactions with miRNAs in lung cancer. Other factors such as HIF-1α, lncRNAs and circRNAs modulate miRNA expression. miRNAs have also value in the diagnosis of lung cancer. Understanding such interactions can pave the way for developing novel therapeutics in near future for lung cancer patients.

Effect of environmental exposures on cancer risk: Emerging role of non-coding RNA shuttled by extracellular vesicles

Environmental and lifestyle exposures have a huge impact on cancer risk; nevertheless, the biological mechanisms underlying this association remain poorly understood. Extracellular vesicles (EVs) are membrane-enclosed particles actively released by all living cells, which play a key role in intercellular communication. EVs transport a variegate cargo of biomolecules, including non-coding RNA (ncRNA), which are well-known regulators of gene expression. Once delivered to recipient cells, EV-borne ncRNAs modulate a plethora of cancer-related biological processes, including cell proliferation, differentiation, and motility. In addition, the ncRNA content of EVs can be altered in response to outer stimuli. Such changes can occur either as an active attempt to adapt to the changing environment or as an uncontrolled consequence of cell homeostasis loss. In either case, such environmentally-driven alterations in EV ncRNA might affect the complex crosstalk between malignant cells and the tumor microenvironment, thus modulating the risk of cancer initiation and progression. In this review, we summarize the current knowledge about EV ncRNAs at the interface between environmental and lifestyle determinants and cancer. In particular, we focus on the effect of smoking, air and water pollution, diet, exercise, and electromagnetic radiation. In addition, we have conducted a bioinformatic analysis to investigate the biological functions of the genes targeted by environmentally-regulated EV microRNAs. Overall, we draw a comprehensive picture of the role of EV ncRNA at the interface between external factors and cancer, which could be of great interest to the development of novel strategies for cancer prevention, diagnosis, and therapy.

Circulating exosomal miRNAs as a promising diagnostic biomarker in cancer

Cancer belongs to multifactorial diseases characterized by uncontrolled growth and proliferation of abnormal cells. Breast cancer, non-small cell lung cancer, and colorectal cancer are the most frequently diagnosed malignancies with a high mortality rate. These carcinomas typically contain multiple genetically distinct subpopulations of tumor cells leading to tumor heterogeneity, which promotes the aggressiveness of the disease. Early diagnosis is necessary to increase patient progression-free survival. Particularly, miRNAs present in exosomes derived from tumors represent potential biomarkers suitable for early cancer diagnosis. Identification of miRNAs by liquid biopsy enables a personalized approach with the subsequent better clinical management of patients. This review article highlights the potential of circulating exosomal miRNAs in early breast, non-small cell lung, and colorectal cancer diagnosis.

Localized Imaging of Programmed Death-Ligand 1 on Individual Tumor-Derived Extracellular Vesicles for Prediction of Immunotherapy Response

Programmed death-ligand 1 (PD-L1) on tumor-derived small extracellular vesicles (EVs) is a biomarker for prediction of the immunotherapy response. However, conventional bulk measurement can hardly analyze the expression of PD-L1 on individual tumor-derived EVs. Herein, a method for localized imaging of tumor-derived individual EVs PD-L1 (LITIE) is developed. In this assay, EVs in plasma were directly captured on a biochip. Then the liposome-mediated membrane fusion strategy was used to image miR-21 in EVs to discriminate miR-21-positive EVs from the whole EVs populations. Subsequently, the primer exchange reaction (PER) is applied to generate localized and amplified fluorescent signals for imaging PD-L1 on identified tumor-derived EVs. When applied in clinical sample tests, the LITIE assay could effectively distinguish breast cancer patients from healthy donors or patients with benign tumors. Interestingly, in a mice melanoma model, the LITIE assay showed the ability to predict immunotherapy response even before drug treatment. Thus, we think the strategy of measuring individual tumor-derived EVs PD-L1 could serve as an alternative way for screening clinical responders suitable for immunotherapy.

Illuminating miRNA Inhibition: Visualizing the Interaction between Anti-miRNA Oligonucleotide and Target miRNA Using FRET

Anti-miRNA oligonucleotides (anti-miRs) effectively and specifically inhibit the function of individual miRNAs and have the potential to serve as a novel class of nucleic acid therapeutic. However, the details of the mechanisms of anti-miRs in cells have not yet been clarified sufficiently. In particular, the localization of the complexes of anti-miRs and target miRNA in cells remains unclear. We previously developed anti-miRs composed of serinol nucleic acid (SNA) that very effectively inhibited miRNA-mediated silencing activity. Here we describe an imaging system based on the fluorescence resonance energy transfer (FRET) designed by miRNAs labeled with fluorophore-quencher pairs and an SNA-based anti-miR labeled with an acceptor dye. We discovered that the anti-miR hybridizes with the miRNA in the miRNA-induced silencing complex (miRISC), which is the active complex formed by miRNA and Ago2 in cells within P-bodies. Based on FRET ratio analysis, we hypothesize that the complex formed by the anti-miR and the miRNA in P-bodies is dynamic, with anti-miR complexing the miRISC, followed by miRNA release and degradation. Our findings provide valuable insights into the mechanism of action of anti-miRs and enable further studies of miRNA-targeted therapeutics.

Engineering siRNA therapeutics: challenges and strategies

Small interfering RNA (siRNA) is a potential method of gene silencing to target specific genes. Although the U.S. Food and Drug Administration (FDA) has approved multiple siRNA-based therapeutics, many biological barriers limit their use for treating diseases. Such limitations include challenges concerning systemic or local administration, short half-life, rapid clearance rates, nonspecific binding, cell membrane penetration inability, ineffective endosomal escape, pH sensitivity, endonuclease degradation, immunological responses, and intracellular trafficking. To overcome these barriers, various strategies have been developed to stabilize siRNA, ensuring their delivery to the target site. Chemical modifications implemented with nucleotides or the phosphate backbone can reduce off-target binding and immune stimulation. Encapsulation or formulation can protect siRNA from endonuclease degradation and enhance cellular uptake while promoting endosomal escape. Additionally, various techniques such as viral vectors, aptamers, cell-penetrating peptides, liposomes, and polymers have been developed for delivering siRNA, greatly improving their bioavailability and therapeutic potential.

Up-regulation of plasma miRNA-21 and miRNA-422a in postmenopausal osteoporosis

BACKGROUND

Many researchers focused on diverse miRNAs in the progression of osteoporosis in postmenopausal women. This study aimed to evaluate the association between plasma miRNA-21-5p and miRNA-422a with osteoporosis in postmenopausal women.

METHODS

This cross-sectional comparative study was performed on 126 randomly selected postmenopausal women aged 50-65, including 65 osteoporotic and 61 normal-bone mineral density (BMD) women. miRNA-21 and miRNA-422a were identified using qRT-PCR in these women. BMD was evaluated by the dual-energy X-ray absorptiometry method. A binary logistic regression model adjusted for confounders was used to evaluate the associations between plasma miRNAs' expression levels and osteoporosis. The Area Under Curve (AUC) was calculated to differentiate low BMD in the postmenopausal period using Receiver-Operator Characteristic (ROC) curves.

RESULTS

miRNA-21 and miRNA-422a were significantly up-regulated in osteoporotic compared to non-osteoporotic postmenopausal women. The expression levels of miRNA-21 and miRNA-422a indicated a significant reverse correlation with both lumbar spine and femoral neck density. After adjusting the confounders, the likelihood of osteoporosis in the postmenopausal women with under the median plasma levels of miRNA-21 (OR = 0.025; 95% CI: 0.003 to 0.198, p<0.001) and miRNA-422a (OR = 0.037; 95% CI: 0.007 to 0.211, p<0.001) was significantly less than the women with the levels above the median. There were significant inverse correlations between miRNA-21 (p<0.001, r = -0.511) and miRNA-422a (p<0.001, r = -0.682) with BMD-lumbar spine as well as an inverse correlation between miRNA-21(p<0.001, r = -0.374) and miRNA-422a (p<0.001, r = -0.602) with BMD-femoral neck. The AUC (95%CI) for miRNA-21 and miRNA-422a was 0.84 (0.77 to 0.91) and 0.98 (0.96 to 0.99), respectively. ROC analysis illustrated that sensitivity and specificity values were 83.1% and 74%, respectively, for miRNA-21 at the cut-off point of 3.38. Also, at the cut-off point of 2.86, a sensitivity of 94% as well as a specificity of 89% was determined for miRNA-422a.

CONCLUSIONS

This study indicated that the odds of osteoporosis in postmenopausal women increased with the higher expression of plasma miRNA-21 and miRNA-422a.

Bioinspired superhydrophobic SERS substrates for machine learning assisted miRNA detection in complex biomatrix below femtomolar limit

Surface-enhanced Raman spectroscopy (SERS) is an analytical method with high potential in the field of medicine. The design of SERS substrates, based on specific morphology and/or chemical modification, allow the recognition of the presence of specific analytes with precision close to a single-molecule detection limit. However, the SERS analysis of real samples is significantly complicated by the presence of a large number of "minor" molecules that can shield the signal from the target analyte and make it impossible to determine it in practice. In this work, an advanced SERS approach was used for the detection of cancer-related miRNA-21 in blood plasma, used as a molecular model background. The approach was based on the combination of the biomimetic plasmon-active SERS substrate, its tuned surface chemistry and advanced SERS data analysis, making use of artificial machine learning. In the first step, biomimetic SERS substrates were created using a butterfly wing as a starting template. The substrates were covered by thin Au layer and covalently grafted with hydrophobic chemical moieties to introduce superhydrophobic and water-adhesive properties. The self-concentration of the analyte on the substrates was achieved by minimizing the contact area between the analyte drop and the substrate, which is facilitated by surface superhydrophobicity and additionally enhanced by drop evaporation on the flipped over substrate. Due to the presence of cancer miRNA and blood plasma background, the measured SERS spectra represent a complex of interfering peaks. Thus, their interpretation was carried out using a specially trained machine learning model. As a result, reliable and repeatable quantitative detection of miRNAs below the femtomolar level (up to 10-16 M) on the background of human blood plasma becomes possible.

Differential Expression Profile of Salivary oncomiRNAs among Smokeless Tobacco Users

OBJECTIVE

 The aim of this study was to evaluate the expression of selected salivary oncomiRNAs among smokeless tobacco users and nonsmokers.

MATERIALS AND METHODS

 Twenty-five subjects with chronic smokeless tobacco habit (> 1 year) and 25 nonsmokers were selected for this study. MicroRNA was extracted from saliva samples using the miRNeasy Kit (Qiagen, Hilden, Germany). The forward primers used in the reactions include hsa-miR-21-5p, hsa-miR-146a-3p, hsa-miR-155-3p, and hsa-miR-199a-3p. Relative expression of miRNAs was calculated using the 2-ΔΔCt method. Fold change is calculated by raising 2 to the power of the negative ΔΔCT value.

STATISTICAL ANALYSIS

 Statistical analysis was carried out using GraphPad Prism 5 software. A p-value less than 0.05 was considered statistically significant.

RESULTS

 The four tested miRNAs were found overexpressed in saliva of subjects with smokeless tobacco habit when compared with saliva from nontobacco users. miR-21 expression was 3.74 ± 2.26 folds higher among subjects with smokeless tobacco habit compared to nontobacco users (p < 0.01). The expression for miR-146a (5.56 ± 8.3 folds; p < 0.05), miR-155 (8.06 ± 23.4 folds; p < 0.0001) and miR-199a (14.39 ± 30.3 folds; p < 0.05) was significantly higher among subjects with smokeless tobacco habit.

CONCLUSION

 Smokeless tobacco leads to salivary overexpression of the miRs 21, 146a, 155, and 199a. Monitoring the levels of these four oncomiRs may provide insight about the future development of oral squamous cell carcinoma, especially in patients with smokeless tobacco habits.

Shikonin Causes an Apoptotic Effect on Human Kidney Cancer Cells through Ras/MAPK and PI3K/AKT Pathways

(1) Background: Shikonin, the main ingredient in Chinese herbal medicine, is described as a novel angiogenesis inhibitor, and its anticancer effects have already been studied. Shikonin and its derivatives induce apoptosis and suppress metastasis, which further enhance the effectiveness of chemotherapy. However, their mechanism of function has not been completely elucidated on human renal cancer cells. (2) Methods: In our study, CAKI-2 and A-498 cells were treated with increasing concentrations (2.5-40 µM) of shikonin, when colony formation ability and cytotoxic activity were tested. The changes in the expression of the main targets of apoptotic pathways were measured by RT-qPCR and Western blot. The intracellular levels of miR-21 and miR-155 were quantified by RT-qPCR. (3) Results: Shikonin exerted a dose-dependent effect on the proliferation of the cell lines examined. In 5 µM concentration of shikonin in vitro elevated caspase-3 and -7 levels, the proteins of the Ras/MAPK and PI3K/AKT pathways were activated. However, no significant changes were detected in the miR-21 and miR-155 expressions. (4) Conclusions: Our findings indicated that shikonin causes apoptosis of renal cancer cells by activating the Ras/MAPK and PI3K/AKT pathways. These effects of shikonin on renal cancer cells may bear important potential therapeutic implications for the treatment of renal cancer.