Metal-organic framework (MOF)-based biosensors for miRNA detection

MicroRNAs (miRNAs) play several crucial roles in the physiological and pathological processes of the human body. They are considered as important biomarkers for the diagnosis of various disorders. Thus, rapid, sensitive, selective, and affordable detection of miRNAs is of great importance. However, the small size, low abundance, and highly similar sequences of miRNAs impose major challenges to their accurate detection in biological samples. In recent years, metal-organic frameworks (MOFs) have been applied as promising sensing materials for the fabrication of different biosensors due to their distinctive characteristics, such as high porosity and surface area, tunable pores, outstanding adsorption affinities, and ease of functionalization. In this review, the applications of MOFs and MOF-derived materials in the fabrication of fluorescence, electrochemical, chemiluminescence, electrochemiluminescent, and photoelectrochemical biosensors for the detection of miRNAs and their detection principle and analytical performance are discussed. This paper attempts to provide readers with a comprehensive knowledge of the fabrication and sensing mechanisms of miRNA detection platforms.

An overview of challenges associated with exosomal miRNA isolation toward liquid biopsy-based ovarian cancer detection

As one of the deadliest gynaecological cancers, ovarian cancer has been on the list. With lesser-known symptoms and lack of an accurate detection method, it is still difficult to catch it early. In terms of both the diagnosis and outlook for cancer, liquid biopsy has come a long way with significant advancements. Exosomes, extracellular components commonly shed by cancerous cells, are nucleic acid-rich particles floating in almost all body fluids and hold enormous promise, leading to minimallyinvasive molecular diagnostics. They have been shown as potential biomarkers in liquid biopsy, being implicated in tumour growth and metastasis. In order to address the drawbacks of ovarian cancer tumor heterogeneity, a liquid biopsy-based approach is being investigated by detecting cell-free nucleic acids, particularly non-coding RNAs, having the advantage of being less invasive and more prominent in nature. microRNAs are known to actively contribute to cancer development and their existence inside exosomes has also been made quite apparent which can be leveraged to diagnose and treat the disease. Extraction of miRNAs and exosomes is an arduous execution, and while other approaches have been investigated, none have produced results that are as encouraging due to limits in time commitment, yield, and, most significantly, damage to the exosomal structure resulting discrepancies in miRNA-based expression profiling for disease diagnosis. We have briefly outlined and reviewed the difficulties with exosome isolation techniques and the need for their standardization. The several widely used procedures and their drawbacks in terms of the exosomal purity they may produce have also been outlined.

LncRNA MIR17HG Suppresses Breast Cancer Proliferation and Migration as ceRNA to Target FAM135A by Sponging miR-454-3p

Breast cancer is one of the most common malignant tumors in women, and causes a large number of cancer-related deaths. The main cause of death of breast cancer patients is tumor recurrence and metastasis. Recent studies show that lncRNA (Long non-coding RNA) plays an important role in breast cancer. However, the overall biological activity and clinical consequences of the lncRNA MIR17HG in breast cancer remain unclear. Thus, we investigate how the MIR17HG/miR-454-3p network impacts breast cancer cell proliferation and migration. Given the TCGA and Oncomine databases, the researchers evaluated variations in MIR17HG expression for the survival rates of breast cancer patients. The influence of MIR17HG on cell proliferation, migration, cell cycle, and the mRNA expression level of miR-454-3p and FAM135A (family with sequence similarity 135 member A) is identified. Luciferase assay was used to detect the regulatory effect of miR-454-3p on the 3'UTR region of FAM135A, and rescue experiments demonstrated that MIR17HG can up-regulate FAM135A expression by competitively binding miR-454-3p. The effect of FAM135A on the cloning and invasion of MCF-7 cells was detected. MIR17HG expression is reduced in breast cancer tissues, and patients with greater levels of MIR17HG expression have a better prognosis. MIR17HG overexpression caused G2/M arrest in breast cancer cells according to a flow cytometry assay. FAM135A knockdown enhances breast cancer cell proliferation and clone creation, as well as two-dimensional and three-dimensional migratory capacities. Patients with high FAM135A expression in their breast cancer had a better prognosis. These novel findings indicate that MIR17HG may be a potential target for breast cancer. Our findings demonstrated that MIR17HG might suppress breast cancer cell proliferation and migration by sponge miR-454-3p through ceRNA(competing endogenous RNAs) mechanism, indicating that targeting MIR17HG may be a feasible therapeutic candidate for breast cancer.

A fuel-initiated DNA molecular machine for microRNA detection in serum via poly-adenine-mediated spherical nucleic acids

MicroRNAs (miRNAs) have been identified as promising disease diagnostic biomarkers. However, it is challenging to sensitively detect miRNAs, especially in complex biological environments, due to their low abundance and small size. Herein, we have developed a DNA-fueled molecular machine for sensitive detection of miRNA-22 (miR-22) in undiluted serum by combining poly-adenine-mediated spherical nucleic acids (polyA-SNAs) with a toehold mediated strand displacement reaction (TMSDR). The polyA-SNAs are constructed by the assembly of diblock DNA probes on a AuNP surface through the high binding affinity of polyA to AuNPs. The surface density of the diblock DNA probe can be controlled by tuning the length of the polyA block, and the orientation of the diblock DNA probe can adopt an upright conformation, which is beneficial to target hybridization and TMSDRs. TMSDR is an enzyme-free target recycling amplification approach. Taking advantage of polyA-mediated SNAs and TMSDR, the operation of the molecular machine based on two successive TMSDRs on polyA20-SNAs is rapid and efficient, which can significantly amplify the fluorescence response for detection of miR-22 in an undiluted complex matrix. The developed sensor can detect as low as 10 pM of target miRNA/DNA in undiluted fetal bovine serum within 30 min. The synergetic effect of polyA-mediated SNAs and TMSDR presents a potential alternative tool for the detection of biomarkers in real biological samples.

The Role of microRNAs in Epigenetic Regulation of Signaling Pathways in Neurological Pathologies

In recent times, there has been a significant increase in researchers' interest in the functions of microRNAs and the role of these molecules in the pathogenesis of many multifactorial diseases. This is related to the diagnostic and prognostic potential of microRNA expression levels as well as the prospects of using it in personalized targeted therapy. This review of the literature analyzes existing scientific data on the involvement of microRNAs in the molecular and cellular mechanisms underlying the development of pathologies such as Alzheimer's disease, cerebral ischemia and reperfusion injury, and dysfunction of the blood-brain barrier.

Electrochemical Biosensors for Whole Blood Analysis: Recent Progress, Challenges, and Future Perspectives

Whole blood, as one of the most significant biological fluids, provides critical information for health management and disease monitoring. Over the past 10 years, advances in nanotechnology, microfluidics, and biomarker research have spurred the development of powerful miniaturized diagnostic systems for whole blood testing toward the goal of disease monitoring and treatment. Among the techniques employed for whole-blood diagnostics, electrochemical biosensors, as known to be rapid, sensitive, capable of miniaturization, reagentless and washing free, become a class of emerging technology to achieve the target detection specifically and directly in complex media, e.g., whole blood or even in the living body. Here we are aiming to provide a comprehensive review to summarize advances over the past decade in the development of electrochemical sensors for whole blood analysis. Further, we address the remaining challenges and opportunities to integrate electrochemical sensing platforms.

Hybridization Chain Reaction-Based Electrochemical Biosensors by Integrating the Advantages of Homogeneous Reaction and Heterogeneous Detection

The conventional hybridization chain reaction (HCR)-based electrochemical biosensors usually require the immobilization of probes on the electrode surface. This will limit the applications of biosensors due to the shortcomings of complex immobilization processes and low HCR efficiency. In this work, we proposed astrategy for the design of HCR-based electrochemical biosensors by integrating the advantages of homogeneous reaction and heterogeneous detection. Specifically, the targets triggered the autonomous cross-opening and hybridization oftwobiotin-labeled hairpin probes to form long-nicked dsDNA polymers. The HCR products with many biotin tags were then captured by a streptavidin-covered electrode, thus allowing for the attachment of streptavidin-conjugated signal reporters through streptavidin-biotin interactions. By employing DNA and microRNA-21 as the model targets and glucose oxidase as the signal reporter, the analytical performances of the HCR-based electrochemical biosensors were investigated. The detection limits of this method were found to be 0.6 fM and 1 fM for DNA and microRNA-21, respectively. The proposed strategy exhibited good reliability for target analysis in serum and cellular lysates. The strategy can be used to develop various HCR-based biosensors for a wide range of applications because sequence-specific oligonucleotides exhibit high binding affinity to a series of targets. In light of the high stability and commercial availability of streptavidin-modified materials, the strategy can be used for the design of different biosensors by changing the signal reporter and/or the sequence of hairpin probes.

A review of sensors for classification and subtype discrimination of cancer: Insights into circulating tumor cells and tumor-derived extracellular vesicles

Liquid biopsy can reflect the state of tumors in vivo non-invasively, thus providing a strong basis for the early diagnosis, individualized treatment monitoring and prognosis of tumors. Circulating tumor cells (CTCs) and tumor-derived extracellular vesicles (tdEVs) contain information-rich components, such as nucleic acids and proteins, and they are essential markers for liquid biopsies. Their capture and analysis are of great importance for the study of disease occurrence and development and, consequently, have been the subject of many reviews. However, both CTCs and tdEVs carry the biological characteristics of their original tissue, and few reviews have focused on their function in the staging and classification of cancer. In this review, we focus on state-of-the-art sensors based on the simultaneous detection of multiple biomarkers within CTCs and tdEVs, with clinical applications centered on cancer classification and subtyping. We also provide a thorough discussion of the current challenges and prospects for novel sensors with the ultimate goal of cancer classification and staging. It is hoped that these most advanced technologies will bring new insights into the clinical practice of cancer screening and diagnosis.

Molecular Diagnosis and Cancer Prognosis-A Concise Review

Cancer is a complicated disease. Globally, it is one of the major causes for morbidity and mortality. A critical challenge associated with it is the difficulty to accurately diagnose it at an early stage. The malignancy due to multistage and heterogeneity that result from genetic and epigenetic modifications poses critical challenge to diagnose and monitor the progress at an early stage. Current diagnostic techniques normally suggest invasive biopsy procedure that can cause further infections and bleeding. Therefore, noninvasive diagnostic methods with high accuracy, safety and earliest detection are the needs of the hour. Herein, we provide a detailed review on the advanced methodologies and protocols developed for the detection of cancer biomarkers based on proteins, nucleic acids and extracellular vesicles. Furthermore, existing challenges and the improvements essential for the rapid, sensitive and noninvasive detection have also been discussed.

State-of-the-Art Fluorescent Probes: Duplex-Specific Nuclease-Based Strategies for Early Disease Diagnostics

Precision healthcare aims to improve patient health by integrating prevention measures with early disease detection for prompt treatments. For the delivery of preventive healthcare, cutting-edge diagnostics that enable early disease detection must be clinically adopted. Duplex-specific nuclease (DSN) is a useful tool for bioanalysis since it can precisely digest DNA contained in duplexes. DSN is commonly used in biomedical and life science applications, including the construction of cDNA libraries, detection of microRNA, and single-nucleotide polymorphism (SNP) recognition. Herein, following the comprehensive introduction to the field, we highlight the clinical applicability, multi-analyte miRNA, and SNP clinical assays for disease diagnosis through large-cohort studies using DSN-based fluorescent methods. In fluorescent platforms, the signal is produced based on the probe (dyes, TaqMan, or molecular beacon) properties in proportion to the target concentration. We outline the reported fluorescent biosensors for SNP detection in the next section. This review aims to capture current knowledge of the overlapping miRNAs and SNPs' detection that have been widely associated with the pathophysiology of cancer, cardiovascular, neural, and viral diseases. We further highlight the proficiency of DSN-based approaches in complex biological matrices or those constructed on novel nano-architectures. The outlooks on the progress in this field are discussed.

A review of highly sensitive electrochemical genosensors for microRNA detection: A novel diagnostic platform for neurodegenerative diseases diagnostics

The significant role of microRNAs in regulating gene expression and in disease tracking has handed the possibility of robust and accurate diagnosis of various diseases. Measurement of these biomarkers has also had a significant impact on the preparation of natural samples. Discovery of miRNAs is a major challenge due to their small size in the real sample and their short length, which is generally measured by complex and expensive methods. Electrochemical nanobiosensors have made significant progress in this field. Due to the delicate nature of nerve tissue repair and the significance of rapid-fire feature of neurodegenerative conditions, these biosensors can be reliably promising. This review presents advances in the field of neurodegenerative diseases diagnostics. At the same time, there are still numerous openings in this field that are a bright prospect for researchers in the rapid-fire opinion of neurological diseases and indeed nerve tissue repair.

Biosensing chips for cancer diagnosis and treatment: a new wave towards clinical innovation

Recent technological advances in nanoscience and material designing have led to the development of point-of-care devices for biomolecule sensing and cancer diagnosis. In situ and portable sensing devices for bedside, diagnosis can effectively improve the patient’s clinical outcomes and reduce the mortality rate. Detection of exosomal RNAs by immuno-biochip with increased sensitivity and specificity to diagnose cancer has raised the understanding of the tumor microenvironment and many other technology-based biosensing devices hold great promise for clinical innovations to conquer the unbeatable fort of cancer metastasis. Electrochemical biosensors are the most sensitive category of biomolecule detection sensors with significantly low concentrations down to the atomic level. In this sense, this review addresses the recent advances in cancer detection and diagnosis by developing significant biological sensing devices that are believed to have better sensing potential than existing facilities.

Effect of Bone Marrow Mesenchymal Stem Cells (BMSCs) with High miR-183-5p Expression on Ovarian Cancer Cells by Regulating Signal Transducer and Activator of Transcription 3 (STAT3)

Currently, the treatment for ovarian cancer (OC) is not satisfactory. The microRNAs may have an important function in tumor pathogenesis. miR-183-5p involves in several tumors. However, its effect on OC cells is unclear. The BMSCs could regulate the micro-environment of tumor and participate in tumor procession. In this study, effect of BMSCs with highly-expressed miR-183-5p on OC cells was assessed. The BMSCs with highly-expressed miR-183-5p was established and co-cultivated with OC cell line SKOV3 followed by measuring miR-183-5p level by PCR, STAT3 and ADAM9 expression by western blot. miR-183-5p level in OC cells was reduced and further decreased after co-culture with BMSCs along with enhance cell proliferation and upregulated STAT3 expression (P < 0.05). In addition, miR-183-5p level was increased in BMSCs with highly-expressed miR-183-5p and STAT3 expression was reduced along with restrained cell proliferation (P < 0.05). In conclusion, miR-183-5p in OC cells is downregulated and malignant biological behaviors of OC cells are restrained by BMSCs with highly-expressed miR-183-5p possibly through regulating the expression of STAT3.

Sensitivity and specificity of microRNA-204, CA125, and CA19.9 as biomarkers for diagnosis of ovarian cancer

Background

Ovarian cancer is usually detected at later stages and no effective screening approach, has been identified. Therefore, sensitive and specific biomarkers for detecting ovarian cancer are urgently needed.

Objective

This study aimed to investigate the efficacy of six biomarkers for the early clinical diagnosis of ovarian cancer.

Subjects & methods

The study included 120 patients (benign ovarian tumors and early and late ovarian carcinoma) and 30 control healthy volunteers. MiRNA-204, CA125, CA19.9, hepcidin, microfibril-associated glycoprotein 2, and ferroportin levels were determined in all patients and control volunteers.

Results

The combined area under the receiver operating characteristic curves for miRNA-204, CA125, and CA19.9 were 0.938, 1.000, and 0.998 for benign tumors and early and late ovarian carcinomas, respectively. The sensitivities of miRNA-204, CA125, and CA19.9 were 98.04%, 100.00%, and 96.19% and the specificities were 58.33%, 62.50%, and 57.78%, respectively.

Conclusion

The positive predictivity of miRNA-204, CA125, and CA19.9 for ovarian cancer is high (59.57%, 58.24%, and 61.67%, respectively). Thus, the combination of these three biomarkers is a good diagnostic tool for ovarian cancer.

Long non-coding RNA ZNFX1 antisense 1 (ZFAS1) suppresses anti-oxidative stress in chondrocytes during osteoarthritis by sponging microRNA-1323

LncRNAs play a regulatory role in osteoarthritis (OA); however, the detailed mechanism remains to be elucidated. This study aimed to investigate the role of lncRNA zinc finger NFX1-type containing 1 (ZNFX1) antisense 1 (ZFAS1) in OA progression and explore its possible mechanismsagainst oxidative stress. Human cartilage specimens were obtained from 10 patients without OA who underwent traumatic amputation and 25 patients with OA who underwent total knee replacement surgery. Chondrocytes were prepared from harvested articular cartilage. ZFAS1, nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1) expression levels were analyzed using quantitative reverse transcription PCR and WB. The chondrocyte growth was indicated by MTT and colony formation assays. Chondrocyte apoptosis, reactive oxygen species generation, and anti-oxidative enzymes activities were also measured. ZFAS1 expression was reduced in OA samples and lipopolysaccharide (LPS)-treated chondrocytes used as an OA cell model mimic. ZFAS1 overexpression facilitated proliferation and repressed oxidative stress, inflammation, and apoptosis in LPS-induced chondrocytes. ZFAS1 also activated the anti-oxidative Nrf2-HO-1 pathway. ZFAS1 directly targeted miR-1323, which partially reversed the effects of ZFAS1 on chondrocyte proliferation, oxidative stress, inflammation, and apoptosis. Furthermore, Nrf2 was negatively regulated by miR-1323. The effect of miR-1323 inhibition was partly abrogated by the administration of brusatol, an Nrf2 inhibitor. Collectively, the results showed that ZFAS1 promoted chondrocyte proliferation and repressed oxidative stress, possibly by regulating the novel miR-1323-Nrf2 axis of the inflammation and apoptosis triggered by LPS, indicating that ZFAS1 is a promising therapeutic target for OA.

Nanomaterial-based biosensor developing as a route toward in vitro diagnosis of early ovarian cancer

The grand challenges of ovarian cancer early diagnosis have led to an alarmingly high mortality rate from ovarian cancer (OC) in the past half century. In vitro diagnosis (IVD) has great potential in the early diagnosis of OC through non-invasive and dynamic analysis of biomarkers. However, common IVDs often fail to provide reliable test results due to lack of sensitivity, specificity, and convenience. In recent years, the discovery of new biomarkers and the progress of nanomaterials can solve the shortcomings of traditional IVD for early OC. These emerging biosensors based on nanomaterials offer great improvements in convenience, speed, selectivity, and sensitivity of IVD. In this review, we firstly systematically summarized the limits of commercial IVD biosensors of OC and the latest discovery of new biomarkers for OC. The representative optimization strategies for six potential ovarian cancer biomarkers are systematically discussed with emphasis on nanomaterial selection and the design of detection principles. Then, various strategies adopted by emerging biosensors based on nanomaterials are also introduced in detail, including optical, electrochemical, microfluidic, and surface plasmon sensors. Finally, current challenges of early OC IVD are proposed, and future research directions on this promising field are also discussed.

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Failure to diagnose OC early will lead to high mortality.

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The detection of OC-related biomarkers by IVD method will achieve early diagnosis of OC.

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The development of nanomaterials-based biosensors is expected to enhance efficiency of detection.

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Strategies and progress for nanomaterials-based biosensors are systematically reviewed.

Fabricated Metal-Organic Frameworks (MOFs) as luminescent and electrochemical biosensors for cancer biomarkers detection

In the health domain, a major challenge is the detection of diseases using rapid and cost-effective techniques. Most of the existing cancer detection methods show poor sensitivity and selectivity and are time consuming with high cost. To overcome this challenge, we analyzed porous fabricated metal-organic frameworks (MOFs) that have better structures and porosities for enhanced biomarker sensing. Here, we summarize the use of fabricated MOF luminescence and electrochemical sensors in devices for cancer biomarker detection. Various strategies of fabrication and the role of fabricated materials in sensing cancer biomarkers have been studied and described. The structural properties, sensing mechanisms, roles of noncovalent interactions, limits of detection, modeling, advantages, and limitations of MOF sensors have been well-discussed. The study presents an innovative technique to detect the cancer biomarkers by the use of luminescence and electrochemical MOF sensors. In addition, the potential association studies have been opening the way for personalized patient treatments and the development of new cancer-detecting devices.

Emerging role and function of miR-198 in human health and diseases

Ever since their discovery, microRNAs (miRNAs/miRs) have astonished us by the plethora of processes they regulate, and thus adding another dimension to the gene regulation. They have been implicated in several diseases affecting cardiovascular, neurodegenerative, hepatic, autoimmune and inflammatory functions. A primate specific exonic miRNA, miR-198 has been vastly studied during the past decade, and shown to have a critical role in wound healing. The aberrant expression of miR-198 was first reported in schizophrenia, linking it to neural development. Later, its dysregulation and tumor suppressive role was reported in hepatocellular carcinoma. However, this was just a beginning, and after which there was an explosion of reports linking miR-198 deregulation to cancers and other ailments. The first target to be identified for miR-198 was Cyclin T1 in monocytes affecting HIV1 replication. Depending on the type of cancer, miR-198 has been shown to function either as a tumor suppressor or an oncomir. Interestingly, miR-198 is not only known to regulate multiple targets and pathways, but also is itself regulated by several circular RNAs and long-non-coding RNAs, highlighting a complex regulatory network. This review highlights the currently understood mechanism and regulation of miR-198 in different diseases, and its possible diagnostic and therapeutic potential.

Progress on the study of the anticancer effects of artesunate

Artesunate (ART) is a derivative of artemisinin that is extracted from the wormwood plant Artemisia annua. ART is an antimalarial drug that has been shown to be safe and effective for clinical use. In addition to its antimalarial properties, ART has been attracting attention over recent years due to its reported inhibitory effects on cancer cell proliferation, invasion and migration. Therefore, ART has a wider range of potential clinical applications than first hypothesized. The aim of the present review was to summarize the latest research progress on the possible anticancer effects of ART, in order to lay a theoretical foundation for the further development of ART as a therapeutic option for cancer.

Ovarian-Cancer-Associated Extracellular Vesicles: Microenvironmental Regulation and Potential Clinical Applications

Ovarian cancer (OC) is one of the most diagnosed gynecological cancers in women. Due to the lack of effective early stage screening, women are more often diagnosed at an advanced stage; therefore, it is associated with poor patient outcomes. There are a lack of tools to identify patients at the highest risk of developing this cancer. Moreover, early detection strategies, therapeutic approaches, and real-time monitoring of responses to treatment to improve survival and quality of life are also inadequate. Tumor development and progression are dependent upon cell-to-cell communication, allowing cancer cells to re-program cells not only within the surrounding tumor microenvironment, but also at distant sites. Recent studies established that extracellular vesicles (EVs) mediate bi-directional communication between normal and cancerous cells. EVs are highly stable membrane vesicles that are released from a wide range of cells, including healthy and cancer cells. They contain tissue-specific signaling molecules (e.g., proteins and miRNA) and, once released, regulate target cell phenotypes, inducing a pro-tumorigenic and immunosuppressive phenotype to contribute to tumor growth and metastasis as well as proximal and distal cell function. Thus, EVs are a “fingerprint” of their cell of origin and reflect the metabolic status. Additionally, via the capacity to evade the immune system and remain stable over long periods in circulation, EVs can be potent therapeutic agents. This review examines the potential role of EVs in the different aspects of the tumor microenvironment in OC, as well as their application in diagnosis, delivery of therapeutic agents, and disease monitoring.

Surface plasmon resonance biosensor for the detection of miRNAs by combining the advantages of homogeneous reaction and heterogeneous detection

The hybridization and enzymolysis reactions for nucleic acid detection were carried out on the chip surface in the traditional surface plasmon resonance (SPR) biosensors. Herein, we proposed an innovative method for microRNA (miRNA) detection in which the hybridization-enzymolysis recycling reactions were performed in solution. Duplex-specific nuclease (DSN) and streptavidin-modified gold nanoparticles (SA-AuNPs) were employed for enhancing the assay sensitivity. In the absence of miRNA, the biotinylated DNA probe (bio-DNA-bio, biotin tags at both the 3' and 5' termini of DNA) was attached to the SA-modified chip through the SA-biotin binding, allowing the capture of SA-AuNPs with the same interaction. As a result, a larger SPR signal was attained. However, in the presence of miRNA, bio-DNA-bio hybridized with miRNA was digested by DSN. In this process, the miRNA strand remained intact and participated in the next hybridization-enzymolysis recycling process. Thus, one miRNA could promote the hydrolysis of many bio-DNA-bio probes and allow the generation of numerous bio-DNA fragments. Meanwhile, the produced bio-DNA competed with the undigested bio-DNA-bio to bind SA on the chip surface. The digestion of bio-DNA-bio and the competitive binding between bio-DNA-bio and bio-DNA led to the attachment of fewer SA-AuNPs and then smaller SPR signals. The change in SPR signal at the concentration as low as 1 fM miRNA has been readily determined. The strategy possessed the advantageous properties of simple operation, fast response, high sensitivity and excellent specificity, serving as a viable means for the fabrication of novel sensing platforms.

The role of PI3K signaling pathway and its associated genes in papillary thyroid cancer

BACKGROUND

One of the well-differentiated types of thyroid cancer is papillary thyroid cancer (PTC), often developed by genetic mutations and radiation.

METHODS

In this study, the public NCBI-GEO database was systematically searched. The eligible datasets were the targets for biomarker discovery associated with PI3K signaling pathway.

RESULTS

Only two datasets were suitable and passed the inclusion criteria. The meta-analysis outcomes revealed eleven upregulation and thirteen downregulation genes differentially expressed between PTC and healthy tissues. Moreover, the outcomes for survival and disease-free rates for each gene were illustrated.

CONCLUSIONS

The present research suggests a panel signature of 24 gene biomarkers in diagnosing the PTC.

Unraveling the Catha edulis Extract Effects on the Cellular and Molecular Signaling in SKOV3 Cells

Khat (Catha edulis (Vahl) Endl.) is an evergreen flowering shrub used as a stimulant in many regions worldwide including East Africa, the Arabian Peninsula, Europe, and the United States. Chewing leaves of khat induces excitement and euphoria, which are primarily attributed to two major constituents, cathinone and cathine. Khat also contains other important constituents such as cathedulins. A considerable number of studies reported side effects induced by the khat extracts to both embryos and adults. These include teratogenicity and developmental retardation, oral cancer and ulcers, high blood pressure, and myocardial infarction. So far, little attention has been paid to the effects of khat extracts on the molecular signaling interactions. We aimed in this study to investigate this through evaluating the effects of khat extracts on SKOV3, a human ovarian adenocarcinoma cell line. We show, by in vitro assays, that khat induces several cellular defects including reduced cell size, cell membrane damage, and apoptosis. At high khat extract concentrations, the cell metabolic activity, cell cycle, and cellular proliferation were affected. RT-qPCR analysis showed an increase in the gene expression of the apoptotic marker BAX, the tumor suppressor p53, and the inflammatory cytokine IL-6. Protein expression analysis by immunostaining showed downregulation of β-catenin, E-cadherin, and Ki-67 and upregulation of FZD8 and SPRY2, suggesting that Wnt and FGF signaling were implicated. SwissTargetPrediction in silico analysis showed that khat constituents cathine, cathinone, catheduline K2, and catheduline E5 bind to family A G-protein-coupled receptor, cause many neurological diseases and disorders such as Alzheimer's, schizophrenia, depression, and anxiety, and induce many ovarian cancer-related diseases. The analysis also showed that important signaling pathways such as CREB, Wnt, FGF, IL-6, and ERK/MAPK, and that of the endometrial cancer, and cell cycle were implicated. Upstream regulators of cathine and cathinone were found to potentially target several molecules including interleukin-8, MMP2, PLAU, and micro-RNAs. In conclusion, khat induces significant cellular and molecular changes that could potentially cause a wide range of serious diseases and syndromes. Such an impact could have a heavy burden on the health care system in the countries where khat is consumed.

Micro-RNA: The darkhorse of cancer

The discovery of micro RNAs (miRNA) in cancer has opened up new vistas for researchers in recent years. Micro RNAs area set of small, endogenous, highly conserved, non-coding RNAs that control the expression of about 30% genes at post-transcriptional levels. Typically, microRNAs impede the translation and stability of messenger RNAs (mRNA), control genes associated with cellular processes namely inflammation, cell cycle regulation, stress response, differentiation, apoptosis, and migration. Compelling findings revealed that miRNA mutations or disruption correspond to diverse human cancers and suggest that miRNAs can function as tumor suppressors or oncogenes. Here we summarize the literature on these master regulators in clinical settings from last three decades as both abrupt cancer therapeutics and as an approach to sensitize tumors to chemotherapy. This review highlights (I) the prevailing perception of miRNA genomics, biogenesis, as well as function; (II) the significant advancements in regulatory mechanisms in the expression of carcinogenic genes; and (III) explains, how miRNA is utilized as a diagnostic and prognostic biomarker for the disease stage indicating survival as well as therapeutic targets in cancer.

Electrochemical Biosensors for Detection of MicroRNA as a Cancer Biomarker: Pros and Cons

Cancer is the second most fatal disease in the world and an early diagnosis is important for a successful treatment. Thus, it is necessary to develop fast, sensitive, simple, and inexpensive analytical tools for cancer biomarker detection. MicroRNA (miRNA) is an RNA cancer biomarker where the expression level in body fluid is strongly correlated to cancer. Various biosensors involving the detection of miRNA for cancer diagnosis were developed. The present review offers a comprehensive overview of the recent developments in electrochemical biosensor for miRNA cancer marker detection from 2015 to 2020. The review focuses on the approaches to direct miRNA detection based on the electrochemical signal. It includes a RedOx-labeled probe with different designs, RedOx DNA-intercalating agents, various kinds of RedOx catalysts used to produce a signal response, and finally a free RedOx indicator. Furthermore, the advantages and drawbacks of these approaches are highlighted.

MicroRNAs Responding to Space Radiation

High-energy and high-atom-number (HZE) space radiation poses an inevitable potential threat to astronauts on deep space exploration missions. Compared with low-LET radiation, high-energy and high-LET radiation in space is more efficient in inducing clustered DNA damage with more serious biological consequences, such as carcinogenesis, central nervous system injury and degenerative disease. Space radiation also causes epigenetic changes in addition to inducing damage at the DNA level. Considering the important roles of microRNAs in the regulation of biological responses of radiation, we systematically reviewed both expression profiling and functional studies relating to microRNAs responding to space radiation as well as to space compound environment. Finally, the directions for improvement of the research related to microRNAs responding to space radiation are proposed. A better understanding of the functions and underlying mechanisms of the microRNAs responding to space radiation is of significance to both space radiation risk assessment and therapy development for lesions caused by space radiation.