The let-7 microRNA represses cell proliferation pathways in human cells

Comparative analysis of miRNA-mRNA interaction prediction tools based on experimental head and neck cancer data

BACKGROUND

We evaluated the performance of TargetScan, miRDB, and miRWalk for predicting miRNA-mRNA interactions in HNSCC. Based on clinical tumor and cancer-free tissue data, miRWalk emerged as the most comprehensive tool. Validation using NanoString technology and MiRTarBase confirmed key predictions, highlighting the important roles of the PI3K-Akt and Wnt pathways. This study underscores the importance of integrating bioinformatics and experimental data to better understand HNSCC.

BACKGROUND

■ miRWalk had the highest predicted interactions and validated miRNA networks in HNSCC.

BACKGROUND

■ Around 3.3% of interactions overlapped across tools, emphasizing the need for multitool approaches.

BACKGROUND

■ Dysregulated genes and miRNAs were tied to cancerdriving PI3K-Akt and Wnt pathways.

BACKGROUND

■ The validated approach highlights the importance of integrating computational and molecular data.

OBJECTIVE

Head and neck squamous cell carcinoma (HNSCC) has a poor prognosis largely due to late diagnosis and a lack of reliable biomarkers. MicroRNAs (miRNAs), small non-coding RNAs that regulate gene expression, are promising biomarkers for HNSCC. This study evaluated miRNA-mRNA interactions in HNSCC using conventional computational tools and validated the results using molecular data.

METHODS

We compared three miRNA-mRNA interaction prediction tools, TargetScan, miRDB, and miRWalk, using differentially expressed miRNAs and mRNAs from HNSCC and cancer-free tissues. NanoString nCounter was used to measure miRNA and mRNA expression and the miRTarBase database was used to validate the predicted miRNA-mRNA interactions.

RESULTS

TargetScan and miRWalk provide a comprehensive overview of potential interactions, whereas miRDB provides functional insights. Our results identified 77 and 154 differentially expressed miRNAs and mRNAs in HNSCC, respectively. miRWalk predicted the highest number of miRNA-mRNA interactions, followed by miRDB and TargetScan. Only 3.3% of interactions were common among the tools. The MiRTarBase analysis confirmed a small subset of the predictions. Biological pathway analysis highlighted the dysregulation of PI3K-Akt and Wnt signaling; miRWalk was the best for elucidating how miRNAs modulate target mRNAs in these key pathways during HNSCC progression.

CONCLUSION

miRWalk emerged as the most robust tool for predicting miRNA-mRNA interactions. Our findings highlight the importance of integrating bioinformatics predictions with experimental data to better understand the regulatory networks in HNSCC and identify potential biomarkers for diagnosis and therapy.

Identification of the dysregulated let-7c-Sox2 network in the facial prominences of mouse embryos with early retinoid acid exposure

RA signaling is crucial for the anteroposterior pattern formation during neural crest induction and acts as a key environmental cue for cranial neural crest cell migration as well as the subsequent mesenchymal proliferation and differentiation. Congenital malformations including cleft lip and palate have been shown associated with altered embryonic RA signaling both in human and in animal models. In this study, a dysregulated let-7c-Sox2 network was identified in the altered transcriptomic profiles of the facial prominences of E12.5 mouse embryos induced by early RA exposure. Ubiquitously increased expression of let-7c was observed in the epithelium and the mesenchyme of facial prominences of the RA treated mouse and chick embryos. Direct binding and regulation between let-7c and Sox2 was verified using luciferase assay and significant negative correlation between let-7c and Sox2 expression was observed in vitro. Reduced Sox2 expression was predominantly identified in the epithelium of maxillary and palate shelves from E10.5 to E12.5 in RA-induced mouse embryos, resulted in oral adhesion and hypoplasia of palatal shelves that could partly be explained by the reduced mesenchymal proliferation due to upregulation of let-7c, as shown by the results of cell proliferation assay in vitro.

PROTAC and Molecular Glue Degraders of the Oncogenic RNA Binding Protein Lin28

The interaction between proteins and RNA is crucial for regulating gene expression, with dysregulation often linked to diseases such as cancer. The RNA-binding protein (RBP) Lin28 inhibits the tumor suppressor microRNA (miRNA) let-7, making it a significant oncogenic factor in tumor progression and metastasis. In this study, a small molecule is used that binds Lin28 and blocks its inhibition of let-7. To enhance its efficay, the inhibitor is transformed into degraders via two degradation approaches: Proteolysis Targeting Chimera (PROTAC) and molecular glue. A series of PROTAC bifunctional molecules and molecular glues capable of degrading Lin28 in cells.is developed Both strategies significantly reduce overexpressed Lin28 and alleviate cancer cellular phenotypes. Notably, the molecular glue approach demonstrates exceptional potency, surpassing PROTAC in several aspects. This outcome underscores the superior efficiency of the molecular glue approach for targeted Lin28 degradation and highlights its potential for addressing associated diseases with small molecules. Innovative small molecule strategies such as molecular glue and PROTAC technology for targeted RBP degradation, hold promise for opening new avenues in RNA modulation and addressing related diseases.

Recent animal models of bladder cancer and their application in drug discovery: an update of the literature

INTRODUCTION

Bladder cancer presents a significant health problem worldwide, with environmental and genetic factors contributing to its incidence. Histologically, it can be classified as carcinoma in situ, non-muscle invasive and muscle-invasive carcinoma, each one with distinct genetic alterations impacting prognosis and response to therapy. While traditional transurethral resection is commonly performed in carcinoma in situ and non-muscle invasive carcinoma, it often fails to prevent recurrence or progression to more aggressive phenotypes, leading to the frequent need for additional treatment such as intravesical chemotherapy or immunotherapy. Despite the advances made in recent years, treatment options for bladder cancer are still lacking due to the complex nature of this disease. So, animal models may hold potential for addressing these limitations, because they not only allow the study of disease progression but also the evaluation of therapies and the investigation of drug repositioning.

AREAS COVERED

This review discusses the use of animal models over the past decade, highlighting key discoveries and discussing advantages and disadvantages for new drug discovery.

EXPERT OPINION

Over the past decade animal models have been employed to evaluate new mechanisms underlying the responses to standard therapies, aiming to optimize bladder cancer treatment. The authors propose that molecular engineering techniques and AI may hold promise for the future development of more precise and effective targeted therapies in bladder cancer.

Cleft Palate Induced by Mycophenolate Mofetil Is Associated with miR-4680-3p and let-7c-5p in Human Palate Cells

Background/Objectives: Cleft palate is a birth defect associated with environmental and genetic factors. Disturbance of microRNAs (miRNAs) and exposure to medicinal agents during pregnancy can cause cleft palate. Although an association between medicine-induced cleft palate and miRNAs has been suggested, it remains to be fully elucidated. This study aimed to clarify the molecular mechanism underlying mycophenolate mofetil (MPM)-induced inhibition of cell proliferation and miRNA expression in human embryonic palatal mesenchymal (HEPM) cells. Methods: Cell viability, apoptosis, and cell cycle-related markers were evaluated 48 h after MPM treatment. In addition, miRNA levels and expression of their downstream genes were measured, and a rescue experiment was performed using miR-4680-3p and/or let-7c-5p inhibitors. Results: MPM dose-dependently reduced HEPM cell viability. Additionally, MPM treatment suppressed cyclin-D1, cyclin E1, cyclin-dependent kinase (CDK)-2, and CDK6 expression in HEPM cells. Furthermore, MPM upregulated miR-4680-3p and let-7c-5p expression and downregulated the downstream genes of each miRNA. Moreover, miR-4680-3p and/or let-7c-5p inhibitors alleviated MPM-induced inhibition of cell proliferation. Conclusions: These results suggest that MPM-induced cleft palate is associated with miR-4680-3p and let-7c-5p expression in HEPM cells.

MicroRNA155 in non-small cell lung cancer: a potential therapeutic target

Lung cancer (LC) is the second most commonly diagnosed cancer among both men and women, and it stands as the leading cause of cancer-related mortality, characterized by high rates of morbidity and mortality. Among its subtypes, non-small cell lung cancer (NSCLC) is the most prevalent and one of the most challenging malignant tumors to treat. To date, various therapeutic approaches, including surgery, radiotherapy, and chemotherapy, have been employed in the management of lung cancer; however, due to its aggressive nature, the survival rates remain low. Consequently, exploring novel treatment strategies is of paramount importance. MicroRNAs (miRNAs), a large family of non-coding RNAs, play crucial roles in regulating several key biological processes, including cell proliferation, differentiation, inflammation, and apoptosis. Among these, microRNA155(miR-155) is one of the most conserved and versatile miRNAs, predominantly overexpressed in various diseases, including malignant tumors. This review elucidates the biological functions and roles of miR-155 in NSCLC and discusses its potential significance as a therapeutic target for future research directions and clinical applications.

The Interplay Between Obesity and Aging in Breast Cancer and Regulatory Function of MicroRNAs in This Pathway

Breast cancer (BC) is a significant contributor to cancer-related deaths in women, and it has complex connections with obesity and aging. This review explores the interaction between obesity and aging in relation to the development and progression of BC, focusing on the controlling role of microRNAs (miRNAs). Obesity, characterized by excess adipose tissue, contributes to a proinflammatory environment and metabolic dysregulation, which are important in tumor development. Aging, associated with cellular senescence and systemic changes, further exacerbates these conditions. miRNAs, small noncoding RNAs that regulate gene expression, play key roles in these processes, impacting pathways involved in cell proliferation, apoptosis, and cancer metastasis, either as tumor suppressors or oncogenes. Importantly, specific miRNAs are implicated in mediating the impact of obesity and aging on BC. Exploring the regulatory networks controlled by miRNAs provides valuable information on new targets for therapy and predictive markers, demonstrating the potential for using miRNA-based interventions to treat BC in obese and elderly individuals. This review emphasizes the importance of integrated research strategies to understand the complex connections between obesity, aging, and miRNA regulation in BC.

Let-7 microRNA targets BmCentrin to modulate the development and functionality of the middle silk gland in the silkworm, Bombyx mori

The silk gland of the silkworm Bombyx mori serves as a valuable model for investigating the morphological structure and physiological functions of organs. Previous studies have demonstrated the notable regulatory role of let-7 microRNA in the silk gland, but its specific molecular mechanism remains to be elucidated across different segments of this organ. In this study, we further investigated the functional mechanism of let-7 in the middle silk gland (MSG). The MSG of a let-7 knockout strain was analyzed using a combined proteomic and metabolomic technique, revealing the enrichment of differential proteins and metabolites in the DNA synthesis and energy metabolism pathways. BmCentrin was identified as a novel target gene of let-7 in the MSG, and its downregulation inhibited the proliferation of BmN4-SID1 cells, which is exactly opposite to the role of let-7 in these cells. CRISPR/Cas9 genome editing and transgenic technologies were employed to manipulate BmCentrin in the MSG. Knockout of BmCentrin led to severe MSG atrophy, whereas the overexpression of BmCentrin resulted in beaded MSG. Further measurements of these knockout or overexpression strains revealed significant changes in the expression levels of sericin protein genes, the weight of the cocoon and the mechanical properties of the silk. Investigating the biological role of BmCentrin in the silk gland offers valuable insights for elucidating the molecular mechanisms by which let-7 controls silk gland development and silk protein synthesis in the silkworm.

Peripheral blood miRNAs are associated with airflow below threshold in children with asthma

BACKGROUND

MicroRNAs (miRNAs) are crucial post-transcriptional regulators involved in inflammatory diseases, such as asthma. Poor lung function and airflow issues in childhood are linked to the development of chronic obstructive pulmonary disease (COPD) in adulthood.

METHODS

We analyzed small RNA-Seq data from 365 peripheral whole blood samples from the Genetics of Asthma in Costa Rica Study (GACRS) for association with airflow levels measured by FEV1/FVC. Differentially expressed (DE) miRNAs were identified using DESeq2 in R, adjusting for covariates and applying a 10% false discovery rate (FDR). The analysis included 361 samples and 649 miRNAs. The two DE miRNAs were further tested for association with airflow obstruction in a study of adult former smokers with and without COPD.

RESULTS

We found 1 upregulated and 1 downregulated miRNA in participants with airflow below the threshold compared to those above it. In the adult study, the same miRNAs were upregulated and downregulated in individuals with FEV1/FVC < 0.7 versus those with FEV1/FVC > 0.7, showing suggestive statistical evidence. The target genes of these miRNAs were enriched for PI3K-Akt, Hippo, WNT, MAPK, and focal adhesion pathways.

CONCLUSIONS

Two differentially expressed miRNAs were associated with airflow levels in children with asthma and airflow obstruction in adults with COPD. This suggests that shared genetic regulatory systems may influence childhood airflow and contribute to adulthood airflow obstruction.

Exosomal ncRNAs in liquid biopsies for lung cancer

Exosomal non-coding RNAs (ncRNAs) have become essential contributors to advancing and treating lung cancers (LCs). The development of liquid biopsies that utilize exosomal ncRNAs (exo-ncRNAs) offers an encouraging method for diagnosing, predicting, and treating LC. This thorough overview examines the dual function of exo-ncRNAs as both indicators for early diagnosis and avenues for LC treatment. Exosomes are tiny vesicles secreted by various cells, including cancerous cells, enabling connection between cells by delivering ncRNAs. These ncRNAs, which encompass circular RNAs, long ncRNAs, and microRNAs, participate in the modulation of gene expression and cellular functions. In LC, certain exo-ncRNAs are linked to tumour advancement, spread, and treatment resistance, positioning them as promising non-invasive indicators in liquid biopsies. Additionally, targeting these ncRNAs offers potential for innovative treatment approaches, whether by suppressing harmful ncRNAs or reinstating the activity of tumour-suppressing ones. This review emphasizes recent developments in the extraction and analysis of exo-ncRNAs, their practical applications in LC treatment, and the challenges and prospects for translating these discoveries into clinical usage. Through this detailed examination of the current state of the art, we aim to highlight the significant potential of exo-ncRNAs for LC diagnostics and treatments.

MicroRNAs: a symphony orchestrating evolution and disease dynamics

The genesis of human disease lies in our evolutionary past. Evolution has featured a general trend towards increased morphological complexity, partly conferred by expansion in gene regulatory capacity via microRNA (miRNA) innovation. Many human diseases are directly related to the evolved roles of these miRNAs, and miRNA-based therapies are emerging as an appealing strategy for precision medicine. We focus on three categories of human disease - cancer, inflammation-linked pathologies, and neurological disorders - which are highly prevalent and are associated with substantial disease burden worldwide. In each category we discuss the pathogenic roles of miRNAs in the context of their evolved functions, as well as current and potential advances in targeting these miRNAs for disease therapy.

Out-of-Equilibrium ceRNA Crosstalk

Among non-coding RNAs, microRNAs are pivotal post-transcriptional regulators of gene expression in higher eukaryotes. Through a titration-based mechanism of interaction with their target RNAs, microRNAs can mediate a weak but pervasive form of RNA cross-regulation, as different endogenous RNAs can be effectively coupled by competing for microRNA binding (a phenomenon now known as "crosstalk"). Mathematical modeling has been proven of great help in unraveling many features of these competing endogenous RNA (ceRNA) interactions. However, although many studies have been devoted to the steady-state properties of this indirect regulatory layer, little is known about how the information encoded in frequency, amplitude, duration, and other features of regulatory signals can affect the resulting ceRNA crosstalk picture and hence the overall patterns of gene expression. Here, we focus on such dynamical aspects, with a special emphasis on the encoding and decoding of time-dependent signals.

Lipid-Based Nanocarriers for Targeted Gene Delivery in Lung Cancer Therapy: Exploring a Novel Therapeutic Paradigm

Lung cancer is a significant cause of cancer-related death worldwide. It can be broadly categorised into small-cell lung cancer (SCLC) and Non-small cell lung cancer (NSCLC). Surgical intervention, radiation therapy, and the administration of chemotherapeutic medications are among the current treatment modalities. However, the application of chemotherapy may be limited in more advanced stages of metastasis due to the potential for adverse effects and a lack of cell selectivity. Although small-molecule anticancer treatments have demonstrated effectiveness, they still face several challenges. The challenges at hand in this context comprise insufficient solubility in water, limited bioavailability at specific sites, adverse effects, and the requirement for epidermal growth factor receptor inhibitors that are genetically tailored. Bio-macromolecular drugs, including small interfering RNA (siRNA) and messenger RNA (mRNA), are susceptible to degradation when exposed to the bodily fluids of humans, which can reduce stability and concentration. In this context, nanoscale delivery technologies are utilised. These agents offer encouraging prospects for the preservation and regulation of pharmaceutical substances, in addition to improving the solubility and stability of medications. Nanocarrier-based systems possess the notable advantage of facilitating accurate and sustained drug release, as opposed to traditional systemic methodologies. The primary focus of scientific investigation has been to augment the therapeutic efficacy of nanoparticles composed of lipids. Numerous nanoscale drug delivery techniques have been implemented to treat various respiratory ailments, such as lung cancer. These technologies have exhibited the potential to mitigate the limitations associated with conventional therapy. As an illustration, applying nanocarriers may enhance the solubility of small-molecule anticancer drugs and prevent the degradation of bio-macromolecular drugs. Furthermore, these devices can administer medications in a controlled and extended fashion, thereby augmenting the therapeutic intervention's effectiveness and reducing adverse reactions. However, despite these promising results, challenges remain that must be addressed. Multiple factors necessitate consideration when contemplating the application of nanoparticles in medical interventions. To begin with, the advancement of more efficient delivery methods is imperative. In addition, a comprehensive investigation into the potential toxicity of nanoparticles is required. Finally, additional research is needed to comprehend these treatments' enduring ramifications. Despite these challenges, the field of nanomedicine demonstrates considerable promise in enhancing the therapy of lung cancer and other respiratory diseases.

DeepMiRBP: a hybrid model for predicting microRNA-protein interactions based on transfer learning and cosine similarity

BACKGROUND

Interactions between microRNAs and RNA-binding proteins are crucial for microRNA-mediated gene regulation and sorting. Despite their significance, the molecular mechanisms governing these interactions remain underexplored, apart from sequence motifs identified on microRNAs. To date, only a limited number of microRNA-binding proteins have been confirmed, typically through labor-intensive experimental procedures. Advanced bioinformatics tools are urgently needed to facilitate this research.

METHODS

We present DeepMiRBP, a novel hybrid deep learning model specifically designed to predict microRNA-binding proteins by modeling molecular interactions. This innovation approach is the first to target the direct interactions between small RNAs and proteins. DeepMiRBP consists of two main components. The first component employs bidirectional long short-term memory (Bi-LSTM) neural networks to capture sequential dependencies and context within RNA sequences, attention mechanisms to enhance the model's focus on the most relevant features and transfer learning to apply knowledge gained from a large dataset of RNA-protein binding sites to the specific task of predicting microRNA-protein interactions. Cosine similarity is applied to assess RNA similarities. The second component utilizes Convolutional Neural Networks (CNNs) to process the spatial data inherent in protein structures based on Position-Specific Scoring Matrices (PSSM) and contact maps to generate detailed and accurate representations of potential microRNA-binding sites and assess protein similarities.

RESULTS

DeepMiRBP achieved a prediction accuracy of 87.4% during training and 85.4% using testing, with an F score of 0.860. Additionally, we validated our method using three case studies, focusing on microRNAs such as miR-451, -19b, -23a, -21, -223, and -let-7d. DeepMiRBP successfully predicted known miRNA interactions with recently discovered RNA-binding proteins, including AGO, YBX1, and FXR2, identified in various exosomes.

CONCLUSIONS

Our proposed DeepMiRBP strategy represents the first of its kind designed for microRNA-protein interaction prediction. Its promising performance underscores the model's potential to uncover novel interactions critical for small RNA sorting and packaging, as well as to infer new RNA transporter proteins. The methodologies and insights from DeepMiRBP offer a scalable template for future small RNA research, from mechanistic discovery to modeling disease-related cell-to-cell communication, emphasizing its adaptability and potential for developing novel small RNA-centric therapeutic interventions and personalized medicine.

Novel Exosomal miRNA Expression in Irradiated Human Keratinocytes

The epidermis, the outer layer of the skin, relies on a delicate balance of cell growth and keratinocyte differentiation for its function and renewal. Recent research has shed light on exosomes' role in facilitating skin communication by transferring molecules like miRNAs, which regulate gene expression post-transcriptionally. Additionally, these factors lead to skin aging through oxidative stress caused by reactive oxygen species (ROS). In this research project, experiments were conducted to study the impact of Sun2000 solar simulator irradiation on exosomal miRNA profiles in HEKa cells. We hypothesized that acute oxidative stress induced by solar simulator irradiation would alter the expression profile of exosomal miRNAs in HEKa cells. The cells were exposed to different durations of irradiation to induce oxidative stress, and the levels of reactive ROS were measured using the CellROX Deep Red flow cytometry assay kit. Exosomes were isolated from both control and irradiated cells, characterized using DLS and SEM techniques, and their miRNAs were extracted and analyzed using qPCR. Solar simulator irradiation led to a time-dependent increase in intracellular ROS and a decrease in cell viability. Exosomal size increased in irradiated cells. Fifty-nine exosomal miRNAs were differentially expressed in irradiated HEKa cells, including hsa-miR-425-5p, hsa-miR-181b-5p, hsa-miR-196b-5p, hsa-miR-376c-3p, and hsa-miR-15a-5p. This study highlights the significant impact of solar radiation on exosomal miRNA expression in keratinocytes, suggesting their potential role in the cellular response to oxidative stress.

Post-transcriptional control drives Aurora kinase A expression in human cancers

Aurora kinase A (AURKA) is a major regulator of the cell cycle. A prominent association exists between high expression of AURKA and cancer, and impairment of AURKA levels can trigger its oncogenic activity. In order to explore the contribution of post-transcriptional regulation to AURKA expression in different cancers, we carried out a meta-analysis of -omics data of 18 cancer types from The Cancer Genome Atlas (TCGA). Our study confirmed a general trend for increased AURKA mRNA in cancer compared to normal tissues and revealed that AURKA expression is highly dependent on post-transcriptional control in several cancers. Correlation and clustering analyses of AURKA mRNA and protein expression, and expression of AURKA-targeting hsa-let-7a miRNA, unveiled that hsa-let-7a is likely involved to varying extents in controlling AURKA expression in cancers. We then measured differences in the short/long ratio (SLR) of the two alternative cleavage and polyadenylation (APA) isoforms of AURKA mRNA across cancers compared to the respective healthy counterparts. We suggest that the interplay between APA and hsa-let-7a targeting of AURKA mRNA may influence AURKA expression in some cancers. hsa-let-7a and APA may also independently contribute to altered AURKA levels. Therefore, we argue that AURKA mRNA and protein expression are often discordant in cancer as a result of dynamic post-transcriptional regulation.

The role of microRNAs in pregnancies complicated by maternal diabetes

With the global prevalence of diabetes increasing, more people of reproductive age are experiencing hyperglycaemic pregnancies. Maternal Type 1 (T1DM) or Type 2 (T2DM) diabetes mellitus, and gestational diabetes mellitus (GDM) are associated with maternal cardiovascular and metabolic complications. Pregnancies complicated by maternal diabetes also increase the risk of short- and long-term health complications for the offspring, including altered fetal growth and the onset of T2DM and cardiometabolic diseases throughout life. Despite advanced methods for improving maternal glucose control, the prevalence of adverse maternal and offspring outcomes associated with maternal diabetes remains high. The placenta is a key organ at the maternal-fetal interface that regulates fetal growth and development. In pregnancies complicated by maternal diabetes, altered placental development and function has been linked to adverse outcomes in both mother and fetus. Emerging evidence suggests that microRNAs (miRNAs) are key molecules involved in mediating these changes. In this review, we describe the role of miRNAs in normal pregnancy and discuss how miRNA dysregulation in the placenta and maternal circulation is associated with suboptimal placental development and pregnancy outcomes in individuals with maternal diabetes. We also discuss evidence demonstrating that miRNA dysregulation may affect the long-term health of mothers and their offspring. As such, miRNAs are potential candidates as biomarkers and therapeutic targets in diabetic pregnancies at risk of adverse outcomes.

Profile of miRNA expression in the hippocampus of epileptic mice and the prediction of potential therapeutic targets

Epilepsy is a common neurological disease. Increasing evidence has highlighted the role of miRNAs in the molecular mechanisms underlying the development of neurological diseases such as epilepsy. In this study, we established a lithium chloride-pilocarpine epilepsy mouse model, performed miRNA sequencing of hippocampal tissue samples, and compared the obtained miRNA expression profile with that of normal control mice to determine differences in expression levels. We found that 55 miRNAs were differentially expressed in status epilepticus mice compared with normal control mice, with 38 upregulated and 17 downregulated miRNAs. Through subsequent analysis of the five downregulated miRNAs (mmu-let-7a-1-3p, mmu-let-7a-2-3p, mmu-let-7c-5p, mmu-let-7d-5p, and mmu-let-7e-5p) with the most significant differences in expression, the key pathways involved included the MAPK signaling pathway and focal adhesion, among others. Therefore, we believe that let-7 family miRNAs may be potential therapeutic targets for epilepsy.

Ultrasensitive Method Enables Liquid Biopsy for the Precise Detection of Circulating MicroRNAs

Due to invasive and serial examinations of bioactive molecules, liquid biopsy (LB) has emerged as a rapid and reliable solution for early disease detection and monitoring. Developing portable devices with high specificity and sensitivity for LB is highly valuable. To realize a generalized approach to increase the sensitivity of LB, we developed an ultrasensitive diagnostic biochip based on the amplification of miRNA by recombinase polymerase amplification and the significant enhancement of fluorescence signals by photonic crystal (PC) materials. The PCs-RPA biochip has a detection limit as low as 0.24 aM, a wide linear range of 8 orders of magnitude, and excellent specificity. Such advantages realize the accurate detection of circulating miRNAs with very low content in clinical serum samples for the precise diagnosis of nonsmall cell lung cancer.

MicroRNA let-7 targets BmCDK1 to regulate cell proliferation and endomitosis of silk gland in the silkworm, Bombyx mori

MicroRNAs play critical roles in multiple developmental processes in insects. Our previous study showed that CRISPR/Cas9-mediated knock down of the microRNA let-7 in silkworms increased the size of larvae and silk glands, thereby improving the silk production capacity. In this study, we elucidate the molecular mechanism underlying of let-7 regulates growth. Identification of differentially expressed genes in response to let-7 knock down revealed enrichment of pathways associated with cell proliferation and DNA replication. let-7 dysregulation affected the cell cycle and proliferation of the Bombyx mori cell line BmN. Dual-luciferase and target site mutation assays showed that BmCDK1 is a direct target gene of let-7, with only 1 binding site on its 3'-untranslated region. RNA interference of BmCDK1 inhibited cell proliferation, but this effect was counteracted by co-transfection with let-7 antagomir. Moreover, let-7 knock down induced BmCDK1 expression and promoted cell proliferation in multiple tissues, and further induced endomitosis in the silk gland in vivo. Knock down of BmCDK1 resulted in abnormal formation of a new epidermis, and larval development was arrested at the 2nd or 3rd molt stage. Taken together, our results demonstrated that BmCDK1 is a novel target of let-7 in cell fate determination, possessing potential for improving silk yield in silkworm.

A study of microRNAs as new prognostic biomarkers in anal cancer patients

BACKGROUND

MicroRNA (MiR) influences the growth of cancer by regulation of mRNA for 50-60% of all genes. We present as per our knowledge the first global analysis of microRNA expression in anal cancer patients and their prognostic impact.

METHODS

Twenty-nine patients with T1-4 N0-3 M0 anal cancer treated with curative intent from September 2003 to April 2011 were included in the study. RNA was extracted from fresh frozen tissue and sequenced using NGS. Differentially expressed microRNAs were identified using the R-package DEseq2 and the endpoints were time to progression (TTP) and cancer specific survival (CSS).

RESULTS

Five microRNAs were significantly associated with 5-year progression free survival (PFS): Low expression of two microRNAs was associated with higher PFS, miR-1246 (100% vs. 55.6%, p = 0.008), and miR-135b-5p (92.9% vs. 59.3%, p = 0.041). On the other hand, high expressions of three microRNAs were associated with higher PFS, miR-148a-3p (93.3% vs. 53.6%, p = 0.025), miR-99a-5p (92.9% vs. 57.1%, p = 0.016), and let-7c-3p (92.9% vs. 57.1%, p = 0.016). Corresponding findings were documented for CSS.

INTERPRETATION

Our study identified five microRNAs as prognostic markers in anal cancer. MiR-1246 and microRNA-135b-5p were oncoMiRs (miRs with oncogene effects), while miR-148a-3p, miR- 99a-5p, and let-7c-3p acted as tumour suppressors in anal cancer patients.

Selective targeting of chemically modified miR-34a to prostate cancer using a small molecule ligand and an endosomal escape agent

Use of tumor-suppressive microRNAs (miRNAs) as anti-cancer agents is hindered by the lack of effective delivery vehicles, entrapment of the miRNA within endocytic compartments, and rapid degradation of miRNA by nucleases. To address these issues, we developed a miRNA delivery strategy that includes (1) a targeting ligand, (2) an endosomal escape agent, nigericin and (3) a chemically modified miRNA. The delivery ligand, DUPA (2-[3-(1,3-dicarboxy propyl) ureido] pentanedioic acid), was selected based on its specificity for prostate-specific membrane antigen (PSMA), a receptor routinely upregulated in prostate cancer-one of the leading causes of cancer death among men. DUPA was conjugated to the tumor suppressive miRNA, miR-34a (DUPA-miR-34a) based on the ability of miR-34a to inhibit prostate cancer cell proliferation. To mediate endosomal escape, nigericin was incorporated into the complex, resulting in DUPA-nigericin-miR-34a. Both DUPA-miR-34a and DUPA-nigericin-miR-34a specifically bound to, and were taken up by, PSMA-expressing cells in vitro and in vivo. And while both DUPA-miR-34a and DUPA-nigericin-miR-34a downregulated miR-34a target genes, only DUPA-nigericin-miR-34a decreased cell proliferation in vitro and delayed tumor growth in vivo. Tumor growth was further reduced using a fully modified version of miR-34a that has significantly increased stability.

The microRNA Let-7 and its exosomal form: Epigenetic regulators of gynecological cancers

Many types of gynecological cancer (GC) are often silent until they reach an advanced stage, and are therefore often diagnosed too late for effective treatment. Hence, there is a real need for more efficient diagnosis and treatment for patients with GC. During recent years, researchers have increasingly studied the impact of microRNAs cancer development, leading to a number of applications in detection and treatment. MicroRNAs are a particular group of tiny RNA molecules that regulate regular gene expression by affecting the translation process. The downregulation of numerous miRNAs has been observed in human malignancies. Let-7 is an example of a miRNA that controls cellular processes as well as signaling cascades to affect post-transcriptional gene expression. Recent research supports the hypothesis that enhancing let-7 expression in those cancers where it is downregulated may be a potential treatment option. Exosomes are tiny vesicles that move through body fluids and can include components like miRNAs (including let-7) that are important for communication between cells. Studies proved that exosomes are able to enhance tumor growth, angiogenesis, chemoresistance, metastasis, and immune evasion, thus suggesting their importance in GC management.

A target-triggered strand displacement-assisted target recycling based on carbon dots-based fluorescent probe and MSNs@PDA nanoparticles for miRNA amplified detection and fluorescence imaging

A target-triggered strand displacement-assisted target recycling based on carbon dots-based fluorescent probe and mesoporous silica nanoparticles@polydopamine (MSNs@PDA) was established to detect miRNA. The surface of MSNs rich in mesopores was coated with a layer of PDA, which can adsorb and quench the fluorescence of single-stranded Fuel DNA with fluorescent carbon dots (CDs) modified at the end through fluorescence resonance energy transfer (FRET). After adding double-stranded DNA-gold nanoparticles (dsDNA-AuNPs) and target let-7a, it will trigger two toehold-mediated strand displacement reactions (TSDR), leading to the recovery of fluorescence and the recycling of target let-7a (excitation wavelength: 380 nm; emission wavelength: 458 nm). The recovery value of fluorescence is proportional to the logarithm of the target microRNA let-7a concentration, thus realizing the sensitivity amplification detection of disease markers. The MSNs@PDA@Fuel DNA-CDs/dsDNA-AuNPs nanoplatform based on the strategy of "on-off-on" and TSDR cyclic amplification may hold great potential as an effective and safe nanoprobe for accurate fluorescence imaging of diseases related to miRNA with low abundances.

The microRNA Let-7f Induces Senescence and Exacerbates Oxidative Stress in Retinal Pigment Epithelial Cells

This study aims to investigate the role of microRNA let-7f in the dysfunction and degeneration of retinal pigment epithelium (RPE) cells through the induction of senescence and oxidative stress. Furthermore, we explore whether let-7f inhibition can protect these cells against sodium iodate (SI)-induced oxidative stress. Oxidative stress and let-7f expression are reciprocally regulated in retinal pigment epithelial cells. Overexpression of let-7f in ARPE-19 cells induced oxidative stress as demonstrated by increased reactive oxygen species (ROS) production as well as senescence. Inhibition of let-7f successfully protected RPE cells from the detrimental effects induced by SI. In addition, let-7f overexpression induced RPE cellular dysfunction by diminishing their migratory capabilities and reducing the phagocytosis of porcine photoreceptor outer segments (POS). Results were further confirmed in vivo by intravitreal injections of SI and let-7f antagomir in C57BL/6 mice. Our results provide strong evidence that let-7f is implicated in the dysfunction of RPE cells through the induction of senescence and oxidative injury. These findings may help to uncover novel and relevant processes in the pathogenesis of dry AMD.

Overexpression of Let-7a mitigates diploidization in mouse androgenetic haploid embryonic stem cells

Mouse androgenetic haploid embryonic stem cells (mAG-haESCs) can be utilized to uncover gene functions, especially those of genes with recessive effects, and to produce semicloned mice when injected into mature oocytes. However, mouse haploid cells undergo rapid diploidization during long-term culture in vitro and subsequently lose the advantages of haploidy, and the factors that drive diploidization are poorly understood. In this study, we compared the small RNAs (sRNAs) of mAG-haESCs, normal embryonic stem cells (ESCs), and mouse round spermatids by high-throughput sequencing and identified distinct sRNA profiles. Several let-7 family members and miR-290-295 cluster microRNAs (miRNAs) were found significantly differentially transcribed. Knockdown and overexpression experiments showed that let-7a and let-7g suppress diploidization while miR-290a facilitates diploidization. Our study revealed the unique sRNA profile of mAG-haESCs and demonstrated that let-7a overexpression can mitigate diploidization in mAG-haESCs. These findings will help us to better understand mAG-haESCs and utilize them as tools in the future.

The RAS oncogene in brain tumors and the involvement of let-7 microRNA

RAS oncogenes are master regulator genes in many cancers. In general, RAS-driven cancers have an oncogenic RAS mutation that promotes disease progression (colon, lung, pancreas). In contrast, brain tumors are not necessarily RAS-driven cancers because RAS mutations are rarely observed. In particular, glioblastomas (the most lethal brain tumor) do not appear to have dominant genetic mutations that are suitable for targeted therapy. Standard treatment for most brain tumors continues to focus on maximal surgical resection, radiotherapy and chemotherapy. Yet the convergence of genomic aberrations such as EGFR, PDGFR and NF1 (some of which are clinically effective) with activation of the RAS/MAPK cascade is still considered a key point in gliomagenesis, and KRAS is undoubtedly a driving gene in gliomagenesis in mice. In cancer, microRNAs (miRNA) are small, non-coding RNAs that regulate carcinogenesis. However, the functional consequences of aberrant miRNA expression in cancer are still poorly understood. let-7 encodes an intergenic miRNA that is classified as a tumour suppressor, at least in lung cancer. Let-7 suppresses a plethora of oncogenes such as RAS, HMGA, c-Myc, cyclin-D and thus suppresses cancer development, differentiation and progression. let-7 family members are direct regulators of certain RAS family genes by binding to the sequences in their 3'untranslated region (3'UTR). let-7 miRNA is involved in the malignant behaviour in vitro-proliferation, migration and invasion-of gliomas and stem-like glioma cells as well as in vivo models of glioblastoma multiforme (GBM) via KRAS inhibition. It also increases resistance to certain chemotherapeutic agents and radiotherapy in GBM. Although let-7 therapy is not yet established, this review updates the current state of knowledge on the contribution of miRNA let-7 in interaction with KRAS to the oncogenesis of brain tumours.

Emerging role of tumor suppressing microRNAs as therapeutics in managing non-small cell lung cancer

Lung cancer (LC) is the second leading cause of death across the globe after breast cancer. There are two types of LC viz. small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). NSCLC accounts for approximately 85% of all LC cases. NSCLC affects smokers and people who do not smoke and mainly arises in bronchi and peripheral lungs tissue. LC is often characterized by the alterations of key genes such as EGFR, Wnt/β-catenin signaling, ALK, MET, K-Ras and p53 and downstream signaling pathways associated with tumor growth, differentiation, and survival. Numerous miRNAs have been discovered as a result of advances in biotechnology to treat LC. Various miRNAs those have been identified to treat LC include mir-Let7, mir-34a, mir-134, mir-16-1, mir-320a, mir-148a, mir-125a-5p, mir-497, mir-29, mir-133a, and mir-29a-3p. These miRNAs target various signaling pathways that are involved in pathogenesis of LC. However, due to rapid RNAse degradation, quick clearance, and heat instability, associated with necked miRNA leads to less effective therapeutic effect against LC. Therefore, to overcome these challenges nanocarrier loaded with miRNAs have been reported. They have been found promising because they have the capacity to target the tumor as well as they can penetrate the tumors deep due to nanometer size. Some of the clinical trials have been performed using miR-34a and let-7 for the treatment of LC. In the present manuscript we highlight the role miRNAs as well as their nanoparticle in tumor suppression.

Molecular mechanisms underlying the regulation of tumour suppressor genes in lung cancer

Tumour suppressor genes play a cardinal role in the development of a large array of human cancers, including lung cancer, which is one of the most frequently diagnosed cancers worldwide. Therefore, extensive studies have been committed to deciphering the underlying mechanisms of alterations of tumour suppressor genes in governing tumourigenesis, as well as resistance to cancer therapies. In spite of the encouraging clinical outcomes demonstrated by lung cancer patients on initial treatment, the subsequent unresponsiveness to first-line treatments manifested by virtually all the patients is inherently a contentious issue. In light of the aforementioned concerns, this review compiles the current knowledge on the molecular mechanisms of some of the tumour suppressor genes implicated in lung cancer that are either frequently mutated and/or are located on the chromosomal arms having high LOH rates (1p, 3p, 9p, 10q, 13q, and 17p). Our study identifies specific genomic loci prone to LOH, revealing a recurrent pattern in lung cancer cases. These loci, including 3p14.2 (FHIT), 9p21.3 (p16INK4a), 10q23 (PTEN), 17p13 (TP53), exhibit a higher susceptibility to LOH due to environmental factors such as exposure to DNA-damaging agents (carcinogens in cigarette smoke) and genetic factors such as chromosomal instability, genetic mutations, DNA replication errors, and genetic predisposition. Furthermore, this review summarizes the current treatment landscape and advancements for lung cancers, including the challenges and endeavours to overcome it. This review envisages inspired researchers to embark on a journey of discovery to add to the list of what was known in hopes of prompting the development of effective therapeutic strategies for lung cancer.

MiRNAs related in signaling pathways of women's reproductive diseases: an overview

BACKGROUND

One of the main health issues that can affect women's health is reproductive diseases, such as polycystic ovary syndrome (PCOS), endometriosis (EMs), uterine leiomyomas (ULs), and ovarian cancer (OC). Although these diseases are very common, we do not have a complete understanding of their underlying cellular and molecular mechanisms. It is important to mention that the majority of patients are diagnosed with these diseases at later stages because of the absence of early diagnostic techniques and dependable molecular indicators. Hence, it is crucial to discover novel and non-invasive biomarkers that have prognostic, diagnostic and therapeutic capabilities. MiRNAs, also known as microRNAs, are small non-coding RNAs that play a crucial role in regulating gene expression at the post-transcriptional level. They are short in length, typically consisting of around 22 nucleotides, and are highly conserved across species. Numerous studies have shown that miRNAs are expressed differently in various diseases and can act as either oncogenes or tumor suppressors.

METHODS

The author conducted a comprehensive review of all the pertinent papers available in web of science, PubMed, Google Scholar, and Scopus databases.

RESULTS

We achieved three goals: providing readers with better information, enhancing search results, and making peer review easier.

CONCLUSIONS

This review focuses on the investigation of miRNAs and their involvement in various reproductive disorders in women, including their molecular targets. Additionally, it explores the role of miRNAs in the development and progression of these disorders.

Systematic integration of molecular and clinical approaches in HCV-induced hepatocellular carcinoma

BACKGROUND

MicroRNAs (miRNAs) play a crucial role in gene expression and regulation, with dysregulation of miRNA function linked to various diseases, including hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). There is still a gap in understanding the regulatory relationship between miRNAs and mRNAs in HCV-HCC. This study aimed to investigate the function and effects of persistent HCV-induced miRNA expression on gene regulation in HCC.

METHODS

MiRNA array data were used to identify differentially expressed miRNAs and their targets, and miRNAs were analyzed via DIANA for KEGG pathways, gene ontology (GO) functional enrichment, and Ingenuity Pathways Analysis (IPA) for hepatotoxicity, canonical pathways, associated network functions, and interactive networks.

RESULTS

Seventeen miRNAs in L-HCV and 9 miRNAs in S-HCV were differentially expressed, and 5 miRNAs in L-HCV and 5 miRNAs in S-HCV were significantly expressed in liver hepatocellular carcinoma (LIHC) tumors. Grouped miRNA survival analysis showed that L-HCV miRNAs were associated with survival in LIHC, and miRNA‒mRNA targets regulated viral carcinogenesis and cell cycle alteration through cancer pathways in LIHC. MiRNA-regulated RCN1 was suppressed through miRNA-oncogene interactions, and suppression of RCN1 inhibited invasion and migration in HCC.

CONCLUSION

Persistent HCV infection induced the expression of miRNAs that act as tumor suppressors by inhibiting oncogenes in HCC. RCN1 was suppressed while miRNAs were upregulated, demonstrating an inverse relationship. Therefore, hsa-miR-215-5p, hsa-miR-10b-5p, hsa-let-7a-5p and their target RCN1 may be ideal biomarkers for monitoring HCV-HCC progression.

Let-7c-5p associate with inhibition of phenobarbital-induced cell proliferation in human palate cells

Cleft palate (CP) is one of the most common congenital diseases, and is accompanied by a complicated etiology. Medical exposure in women is among one of the reasons leading to CP. Recently, it has been reported that microRNA (miRNA) plays a crucial role in palate formation and the disruption of miRNA that influence the development of CP. Although association with pharmaceuticals and miRNAs were suggested, it has remained largely unknow. The aim of the current investigation is to elucidate upon the miRNA associated with the inhibition of phenobarbital (PB)-induced cell proliferation in human embryonic palatal mesenchymal (HEPM) cells. We showed that PB inhibited HEPM cell viability in a dose-dependent manner. We demonstrated that PB treatment suppressed cyclin-D1 expression in HEPM cells. Furthermore, PB upregulated let-7c-5p expression and downregulated the expression of two downstream genes (BACH1 and PAX3). Finally, we demonstrated that the let-7c-5p inhibitor alleviated PB-induced inhibition of cell proliferation and altered BACH1 and PAX3 expression levels. These results suggest that PB suppresses cell viability by modulating let-7c-5p expression.

Tumor suppressor let-7 acts as a key regulator for pluripotency gene expression in Muse cells

In embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), the expression of an RNA-binding pluripotency-relevant protein, LIN28, and the absence of its antagonist, the tumor-suppressor microRNA (miRNA) let-7, play a key role in maintaining pluripotency. Muse cells are non-tumorigenic pluripotent-like stem cells residing in the bone marrow, peripheral blood, and organ connective tissues as pluripotent surface marker SSEA-3(+). They express pluripotency genes, differentiate into triploblastic-lineage cells, and self-renew at the single cell level. Muse cells do not express LIN28 but do express let-7 at higher levels than in iPSCs. In Muse cells, we demonstrated that let-7 inhibited the PI3K-AKT pathway, leading to sustainable expression of the key pluripotency regulator KLF4 as well as its downstream genes, POU5F1, SOX2, and NANOG. Let-7 also suppressed proliferation and glycolysis by inhibiting the PI3K-AKT pathway, suggesting its involvement in non-tumorigenicity. Furthermore, the MEK/ERK pathway is not controlled by let-7 and may have a pivotal role in maintaining self-renewal and suppression of senescence. The system found in Muse cells, in which the tumor suppressor let-7, but not LIN28, tunes the expression of pluripotency genes, might be a rational cell system conferring both pluripotency-like properties and a low risk for tumorigenicity.

Development of a regenerable dual-trigger tripedal DNA walker electrochemical biosensor for sensitive detection of microRNA-155

Since microRNAs (miRNAs) are valuable biomarkers for disease diagnosis and prognosis, the pursuit of enhanced detection sensitivity through signal amplification strategies has emerged as a prominent focus in low-abundance miRNA detection research. DNA walkers, as dynamic DNA nanodevice, have gained significant attention for their applications as signal amplification strategies. To overcome the limitations of unipedal DNA walkers with a restricted signal amplification efficiency, there is a great need for multi-pedal DNA walkers that offer improved walking and signal amplification capabilities. Here, we employed a combination of catalytic hairpin assembly (CHA) and APE1 enzymatic cleavage reactions to construct a tripedal DNA walker, driving its movement to establish a cascade signal amplification system for the electrochemical detection of miRNA-155. The biosensor utilizes tumor cell-endogenous microRNA-155 and APE1 as dual-trigger for DNA walker formation and walking movement, leading to highly efficient and controllable signal amplification. The biosensor exhibited high sensitivity, with a low detection limit of 10 pM for microRNA-155, and successfully differentiated and selectively detected microRNA-155 from other interfering RNAs. Successful detection in 20 % serum samples indicates its potential clinical application. In addition, we harnessed strand displacement reactions to create a gentle yet efficient electrode regeneration strategy, to addresses the time-consuming challenges during electrode modification processes. We have successfully demonstrated the stability of current signals even after multiple cycles of electrode regeneration. This study showcased the high-efficiency amplification potential of multi-pedal DNA walkers and the effectiveness and versatility of strand displacement in biosensing applications. It opens a promising path for developing regenerable electrochemical biosensors. This regenerable strategy for electrochemical biosensors is both label-free and cost-effective, and holds promise for detecting various disease-related RNA targets beyond its current application.

Differential microRNAs Expression during Cancer Development, and Chemoprevention by Natural Compounds: A Comprehensive Review

MicroRNAs are short non-coding RNAs that inhibit gene expression at the post-transcriptional level. Abnormal microRNA expression has been associated with different human diseases, including cancer. Epigenetic changes, mutation, transcriptional deregulation, DNA copy number abnormalities, and defects in the biogenesis machinery play an important role in abnormal microRNA expression. Modulation of microRNAs by natural agents has emerged to enhance the efficacy of conventional chemotherapy through combinatorial therapeutic approach. This review summarizes the current understanding of abnormal microRNA expression in cancer, the different cellular mechanisms of microRNA, and their prevention by natural compounds. Understanding microRNA expression patterns during cancer development may help to identify stage-specific molecular markers. Natural compounds that exert regulatory effects by modulating microRNAs can be used in better cancer chemopreventive strategies by directly targeting microRNAs or as a way to increase sensitivity to existing chemotherapy regimens.

MicroRNAs in infectious diseases: potential diagnostic biomarkers and therapeutic targets

MicroRNAs (miRNAs) are conserved, short, non-coding RNAs that play a crucial role in the post-transcriptional regulation of gene expression. They have been implicated in the pathogenesis of cancer and neurological, cardiovascular, and autoimmune diseases. Several recent studies have suggested that miRNAs are key players in regulating the differentiation, maturation, and activation of immune cells, thereby influencing the host immune response to infection. The resultant upregulation or downregulation of miRNAs from infection influences the protein expression of genes responsible for the immune response and can determine the risk of disease progression. Recently, miRNAs have been explored as diagnostic biomarkers and therapeutic targets in various infectious diseases. This review summarizes our current understanding of the role of miRNAs during viral, fungal, bacterial, and parasitic infections from a clinical perspective, including critical functional mechanisms and implications for their potential use as biomarkers and therapeutic targets.

Exploring Lin28 proteins: Unravelling structure and functions with emphasis on nervous system malignancies

Cancer and stem cells share many characteristics related to self-renewal and differentiation. Both cell types express the same critical proteins that govern cellular stemness, which provide cancer cells with the growth and survival benefits of stem cells. LIN28 is an example of one such protein. LIN28 includes two main isoforms, LIN28A and LIN28B, with diverse physiological functions from tissue development to control of pluripotency. In addition to their physiological roles, LIN28A and LIN28B affect the progression of several cancers by regulating multiple cancer hallmarks. Altered expression levels of LIN28A and LIN28B have been proposed as diagnostic and/or prognostic markers for various malignancies. This review discusses the structure and modes of action of the different LIN28 proteins and examines their roles in regulating cancer hallmarks with a focus on malignancies of the nervous system. This review also highlights some gaps in the field that require further exploration to assess the potential of targeting LIN28 proteins for controlling cancer.

microRNAs in exhaled breath condensate for diagnosis of lung cancer in a resource-limited setting: a concise review

Lung cancer is one of the common cancers globally with high mortality and poor prognosis. Most cases of lung cancer are diagnosed at an advanced stage due to limited diagnostic resources. Screening modalities, such as sputum cytology and annual chest radiographs, have not proved sensitive enough to impact mortality. In recent years, annual low-dose computed tomography has emerged as a potential screening tool for early lung cancer detection, but it may not be a feasible option for developing countries. In this context, exhaled breath condensate (EBC) analysis has been evaluated recently as a noninvasive tool for lung cancer diagnosis. The breath biomarkers also have the advantage of differentiating various types and stages of lung cancer. Recent studies have focused more on microRNAs (miRNAs) as they play a key role in tumourigenesis by regulating the cell cycle, metastasis and angiogenesis. In this review, we have consolidated the current published literature suggesting the utility of miRNAs in EBC for the detection of lung cancer.

MiRNA-Responsive CRISPR-Cas System via a DNA Regulator

Clustered regularly interspaced short palindromic repeats (CRISPR)- CRISPR-associated protein 9 (Cas9) genome editing technology is widely used for gene editing because it provides versatility in genetic manipulation. Several methods for regulating CRISPR activity already exist for accurate editing, but these require complex engineering. Thus, a simple and convenient regulatory system is required. In this study, we devised a CRISPR activation system using a DNA regulator that can be activated by miRNAs. The designed regulator was divided into two parts. The inhibition component consisted of the protospacer-adjacent motif (PAM) and seed sequence, which are important for Cas9 target recognition and bind to the ribonucleoprotein (RNP) complex for inhibition. The miRNA recognition component has a single-stranded toehold DNA for target miRNA binding and a partial double-stranded DNA complementary to the remaining miRNA sequence. In the presence of target miRNAs, the structure of the regulator is disrupted by the miRNAs, leading to its dissociation from the RNP complex and subsequent restoration of CRISPR activity. This method is easy to design and can be applied to various miRNAs via simple sequence manipulation. Therefore, this strategy provides a general platform for controlled genome editing.

Prospects of microRNAs as therapeutic biomarkers in non-small cell lung cancer

Lung Cancer, the second most common cancer worldwide, remains the leading cause of cancer-related deaths, contemporarily. More than 85% of identified lung cancer cases are comprised of non-small-cell lung carcinoma (NSCLC). Despite the best advancements in the realm of NSCLC therapy, the five-year survival period of NSCLC patients remains unchanged. Underlying complex molecular heterogeneity, delay in early detection resulting in progression of the disease to its advanced stage and acquired resistance of NSCLC cells during therapy have posed additional challenges for circumventing the discrepancies in treatment strategy. microRNAs (miRNAs) are a class of non-coding RNAs, identified as molecules playing an indispensable role in tumorigenesis & progression and metastasis of several cancers, including NSCLC, either by possessing tumor suppressor or by oncogenic functions. As observed across several studies, miRNA dysregulation has been recognised as a causative mechanism behind NSCLC tumorigenesis. In this review, we discuss the role of miRNAs in NSCLC tumor progression caused by their dysregulation, thereby stating their potential therapeutic application in NSCLC as therapeutic biomarkers. We have also highlighted the recent findings of some of the most widely studied tumor suppressor (miR-486, miR-7 miR-34), and oncogene miRNAs (miR-21, miR-224, miR-135b) that can be further explored for its therapeutic potentialities in the management of NSCLC.

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.

C1632 inhibits ovarian cancer cell growth and migration by inhibiting LIN28 B/let-7/FAK signaling pathway and FAK phosphorylation

The highly conserved RNA-binding protein LIN28B and focal adhesion kinase (FAK) are significantly upregulated in ovarian cancer (OC), serving as markers for disease progression and prognosis. Nonetheless, the correlation between LIN28B and FAK, as well as the pharmacological effects of the LIN28 inhibitor C1632, in OC cells have not been elucidated. The present study demonstrates that C1632 significantly reduced the rate of DNA replication, arrested the cell cycle at the G0/G1 phase, consequently reducing cell viability, and impeding clone formation. Moreover, treatment with C1632 decreased cell-matrix adhesion, as well as inhibited cell migration and invasion. Further mechanistic studies revealed that C1632 inhibited the OC cell proliferation and migration by concurrently inhibiting LIN28 B/let-7/FAK signaling pathway and FAK phosphorylation. Furthermore, C1632 exhibited an obvious inhibitory effect on OC cell xenograft tumors in mice. Altogether, these findings identified that LIN28 B/let-7/FAK is a valuable target in OC and C1632 is a promising onco-therapeutic agent for OC treatment.

In Vitro microRNA Expression Profile Alterations under CDK4/6 Therapy in Breast Cancer

BACKGROUND

Breast cancer is the most common type of cancer worldwide. Cyclin-dependent kinase inhibition is one of the backbones of metastatic breast cancer therapy. However, there are a significant number of therapy failures. This study evaluates the biomarker potential of microRNAs for the prediction of a therapy response under cyclin-dependent kinase inhibition.

METHODS

This study comprises the analysis of intracellular and extracellular microRNA-expression-level alterations of 56 microRNAs under palbociclib mono as well as combination therapy with letrozole. Breast cancer cell lines BT-474, MCF-7 and HS-578T were analyzed using qPCR.

RESULTS

A palbociclib-induced microRNA signature could be detected intracellularly as well as extracellularly. Intracellular miR-10a, miR-15b, miR-21, miR-23a and miR-23c were constantly regulated in all three cell lines, whereas let-7b, let-7d, miR-15a, miR-17, miR-18a, miR-20a, miR-191 and miR301a_3p were regulated only in hormone-receptor-positive cells. Extracellular miR-100, miR-10b and miR-182 were constantly regulated across all cell lines, whereas miR-17 was regulated only in hormone-receptor-positive cells.

CONCLUSIONS

Because they are secreted and significantly upregulated in the microenvironment of tumor cells, miRs-100, -10b and -182 are promising circulating biomarkers that can be used to predict or detect therapy responses under CDK inhibition. MiR-10a, miR-15b, miR-21, miR-23a and miR-23c are potential tissue-based biomarkers.

Himalayan flora: targeting various molecular pathways in lung cancer

The fatal amplification of lung cancer across the globe and the limitations of current treatment strategies emphasize the necessity for substitute therapeutics. The incorporation of phyto-derived components in chemo treatment holds promise in addressing those challenges. Despite the significant progressions in lung cancer therapeutics, the complexities of molecular mechanism and pathways underlying this disease remain inadequately understood, necessitating novel biomarker targeting. The Himalayas, abundant in diverse plant varieties with established chemotherapeutic potential, presents a promising avenue for investigating potential cures for lung carcinoma. The vast diversity of phytocompounds herein can be explored for targeting the disease. This review delves into the multifaceted targets of lung cancer and explores the established phytochemicals with their specific molecular targets. It emphasizes comprehending the intricate pathways that govern effective therapeutic interventions for lung cancer. Through this exploration of Himalayan flora, this review seeks to illuminate potential breakthroughs in lung cancer management using natural compounds. The amalgamation of Himalayan plant-derived compounds with cautiously designed combined therapeutic approaches such as nanocarrier-mediated drug delivery and synergistic therapy offers an opportunity to redefine the boundaries of lung cancer treatment by reducing the drug resistance and side effects and enabling an effective targeted delivery of drugs. Furthermore, additional studies are obligatory to understand the possible derivation of natural compounds used in current lung cancer treatment from plant species within the Himalayan region.

Emerging roles of miR-145 in gastrointestinal cancers: A new paradigm

Gastrointestinal (GI) carcinomas are a group of cancers affecting the GI tract and digestive organs, such as the gastric, liver, bile ducts, pancreas, small intestine, esophagus, colon, and rectum. MicroRNAs (miRNAs) are small functional non-coding RNAs (ncRNAs) which are involved in regulating the expression of multiple target genes; mainly at the post-transcriptional level, via complementary binding to their 3'-untranslated region (3'-UTR). Increasing evidence has shown that miRNAs have critical roles in modulating of various physiological and pathological cellular processes and regulating the occurrence and development of human malignancies. Among them, miR-145 is recognized for its anti-oncogenic properties in various cancers, including GI cancers. MiR-145 has been implicated in diverse biological processes of cancers through the regulation of target genes or signaling, including, proliferation, differentiation, tumorigenesis, angiogenesis, apoptosis, metastasis, and therapy resistance. In this review, we have summarized the role of miR-145 in selected GI cancers and also its downstream molecules and cellular processes targets, which could lead to a better understanding of the miR-145 in these cancers. In conclusion, we reveal the potential diagnostic, prognostic, and therapeutic value of miR-145 in GI cancer, and hope to provide new ideas for its application as a biomarker as well as a therapeutic target for the treatment of these cancer.

Dual mechanism of Let-7i in tumor progression

Let-7i regulates tumors primarily by binding to the 3' untranslated region (3' UTR) of mRNA, which indirectly regulates post-transcriptional gene expression. Let-7i also has an epigenetic function via modulating DNA methylation to directly regulate gene expression. Let-7i performs a dual role by inducing both the promotion and inhibition of various malignancies, depending on its target. The mechanism of Let-7i action involves cancer cell proliferation, migration, invasion, apoptosis, epithelial-mesenchymal transition, EV transmission, angiogenesis, autophagy, and drug resistance sensitization. Let-7i is closely related to cancer, and hence, is a potential biomarker for the diagnosis and prognosis of various cancers. Therapeutically, it can be used to promote an anti-cancer immune response by modifying exosomes, thus exerting a tumor-suppressive effect.

Revisiting of TAMs in tumor immune microenvironment: Insight from NF-κB signaling pathway

Tumor-associated macrophages (TAMs) are key components of tumor immune microenvironment and play a dual role in promoting tumor growth and anti-tumor immunity. Therefore, regulating TAMs has become a promising method in cancer immunotherapy. NF- κB pathway is the key regulatory pathway of TAMs. Targeting this pathway has shown the potential to improve tumor immune microenvironment. At present, there are still some controversies and the idea of combined therapy in this field. This article reviews the progress in the field of immunotherapy in improving tumor immune microenvironment by exploring the mechanism of regulating TAMs (including promoting M1 polarization, inhibiting M2 polarization and regulating TAMs infiltration).

The oncogenic function of PLAGL2 is mediated via ASCL2 and IGF2 and a Wnt-independent mechanism in colorectal cancer

Colorectal cancer (CRC) tumorigenesis and progression are linked to common oncogenic mutations, especially in the tumor suppressor APC, whose loss triggers the deregulation of TCF4/β-Catenin activity. CRC tumorigenesis is also driven by multiple epimutational modifiers such as transcriptional regulators. We describe the common (and near-universal) activation of the zinc finger transcription factor and Let-7 target PLAGL2 in CRC and find that it is a key driver of intestinal epithelial transformation. PLAGL2 drives proliferation, cell cycle progression, and anchorage-independent growth in CRC cell lines and nontransformed intestinal cells. Investigating effects of PLAGL2 on downstream pathways revealed very modest effects on canonical Wnt signaling. Alternatively, we find pronounced effects on the direct PLAGL2 target genes IGF2, a fetal growth factor, and ASCL2, an intestinal stem cell-specific bHLH transcription factor. Inactivation of PLAGL2 in CRC cell lines has pronounced effects on ASCL2 reporter activity. Furthermore, ASCL2 expression can partially rescue deficits of proliferation and cell cycle progression caused by depletion of PLAGL2 in CRC cell lines. Thus, the oncogenic effects of PLAGL2 appear to be mediated via core stem cell and onco-fetal pathways, with minimal effects on downstream Wnt signaling.NEW & NOTEWORTHY A Let-7 target called PLAGL2 drives oncogenic transformation via Wnt-independent pathways. This work illustrates the robust effects of this zinc finger transcription factor in colorectal cancer (CRC) cell lines and nontransformed intestinal epithelium, with effects mediated, in part, via the direct target genes ASCL2 and IGF2. This has implications for the role of PLAGL2 in activation of onco-fetal and onco-stem cell pathways, contributing to immature and highly proliferative phenotypes in CRC.

Influence of Extracellular Vesicles on Lung Stromal Cells during Breast Cancer Metastasis

Breast cancer is a prominent cause of cancer diagnosis and death in women globally, with over 90% of deaths being attributed to complications that arise from metastasis. One of the common locations for breast cancer metastasis is the lung, which is associated with significant morbidity and mortality. Curative treatments for metastatic breast cancer patients are not available and the molecular mechanisms that underlie lung metastasis are not fully understood. In order to better treat these patients, identifying events that occur both prior to and during metastatic spread to the lung is essential. Several studies have demonstrated that breast cancer-derived extracellular vesicles secreted from the primary breast tumor play a key role in establishing the lung pre-metastatic niche to support colonization of metastatic tumor cells. In this review, we summarize recent work supporting the influence of extracellular vesicles on stromal components of the lung to construct the pre-metastatic niche and support metastasis. Furthermore, we discuss the potential clinical applications of utilizing extracellular vesicles for diagnosis and treatment. Together, this review highlights the dynamic nature of extracellular vesicles, their roles in breast cancer metastasis to the lung, and their value as potential biomarkers and therapeutics for cancer prevention.

Oncogenic K-Ras suppresses global miRNA function

K-Ras frequently acquires gain-of-function mutations (K-RasG12D being the most common) that trigger significant transcriptomic and proteomic changes to drive tumorigenesis. Nevertheless, oncogenic K-Ras-induced dysregulation of post-transcriptional regulators such as microRNAs (miRNAs) during oncogenesis is poorly understood. Here, we report that K-RasG12D promotes global suppression of miRNA activity, resulting in the upregulation of hundreds of targets. We constructed a comprehensive profile of physiological miRNA targets in mouse colonic epithelium and tumors expressing K-RasG12D using Halo-enhanced Argonaute pull-down. Combining this with parallel datasets of chromatin accessibility, transcriptome, and proteome, we uncovered that K-RasG12D suppressed the expression of Csnk1a1 and Csnk2a1, subsequently decreasing Ago2 phosphorylation at Ser825/829/832/835. Hypo-phosphorylated Ago2 increased binding to mRNAs while reducing its activity to repress miRNA targets. Our findings connect a potent regulatory mechanism of global miRNA activity to K-Ras in a pathophysiological context and provide a mechanistic link between oncogenic K-Ras and the post-transcriptional upregulation of miRNA targets.