Altered expression of serum lncRNA CASC2 and miRNA-21-5p in COVID-19 patients.

Infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) has a high incidence of spread. On January 30, 2020, the World Health Organization proclaimed a public health emergency of worldwide concern. More than 6.9 million deaths and more than 768 million confirmed cases had been reported worldwide as of June 18, 2023. This study included 51 patients and 50 age- and sex-matched healthy subjects. The present study aimed to identify the expression levels of lncRNA CASC2 and miRNA-21-5p (also known as miRNA-21) in COVID-19 patients and their relation to the clinicopathological characteristics of the disease. The expression levels of noncoding RNAs were measured by RT-PCR technique. Results detected that CASC2 was significantly downregulated while miRNA-21-5p was significantly upregulated in COVID-19 patients compared to healthy subjects. A significant negative correlation was found between CASC2 and miRNA-21-5p. ROC curve analysis used to distinguish COVID-19 patients from controls. MiRNA-21-p serum expression level had a significant positive association with temperature and PO2 (p = 0.04 for each). These findings indicate that CASC2 and miRNA-21-p might be used as potential diagnostic and therapeutic biomarkers in COVID-19.

Fluorescence biosensor to detect microRNAs via integrating DNA hairpins transition mediated strand displacement amplification with primer exchange reaction.

Herein, we constructed a fluorescence biosensor for the ultra-sensitive analysis of microRNAs (miRNAs) by combining DNA hairpins transition triggered strand displacement amplification (DHT-SDA) with primer exchange reaction (PER). Target miRNA initiated DHT-SDA to facilitate the generation of multiple single-stranded DNA (ssDNA) as PER primer, which was extended into a long ssDNA. The biosensor is successfully utilized in detecting miRNAs with high sensitivity (limit of detection for miRNA-21 was 58 fM) and a good linear relationship between 100 nM and 100 fM. By simply changing the DNA hairpin sequence, the constructed biosensor can be extended to analyze another miRNAs. Moreover, the biosensor has the feasibility of detecting miRNAs in real samples with satisfactory accuracy and reliability. Therefore, the fluorescent biosensor has great application potential in clinical diagnosis.

A Photoelectrochemical Biosensor Mediated by CRISPR/Cas13a for Direct and Specific Detection of MiRNA-21.

Direct detection of miRNA is currently limited by the complex amplification and reverse transcription processes of existing methods, leading to low sensitivity and high operational demands. Herein, we developed a CRISPR/Cas13a-mediated photoelectrochemical (PEC) biosensing platform for direct and sensitive detection of miRNA-21. The direct and specific recognition of target miRNA-21 by crRNA-21 eliminates the need for pre-amplification and reverse transcription of miRNA-21, thereby preventing signal distortion and enhancing the sensitivity and precision of target detection. When crRNA-21 binds to miRNA-21, it activates the trans-cleavage activity of CRISPR/Cas13a, leading to the non-specific cleavage of biotin-modified DNA with uracil bases (biotin-rU-DNA). This cleavage prevents the biotin-rU-DNA from being immobilized on the electrode surface. As a result, streptavidin cannot attach to the electrode via specific biotin binding, reducing spatial resistance and causing a positively correlated increase in the photocurrent response. This Cas-PEC biosensor has good analytical capabilities, linear responses between 10 fM and 10 nM, a minimum detection limit of 9 fM, and an excellent recovery rate in the analysis of real human serum samples. This work presented an innovative solution for detecting other biomarkers in bioanalysis and clinical diagnostics.

Plasma miRNA-146b-3p, -222-3p, -221-5p, -21a-3p Expression Levels and TSHR Methylation: Diagnostic Potential and Association with Clinical and Pathological Features in Papillary Thyroid Cancer.

This study aimed to investigate the expression of microRNAs (miRNAs) -146b-3p, -221-5p, -222-3p, and -21a-3p and the methylation pattern of the thyroid-stimulating hormone receptor (TSHR) gene in blood plasma samples from papillary thyroid cancer (PTC) patients before and after thyroidectomy compared to healthy controls (HCs). This study included 103 participants, 46 PTC patients and 57 HCs, matched for gender and age. Significantly higher preoperative expression levels of miRNAs and TSHR methylation were determined in the PTC patients compared to HCs. Post-surgery, there was a notable decrease in these biomarkers. Elevated TSHR methylation was linked to larger tumor sizes and lymphovascular invasion, while increased miRNA-222-3p levels correlated with multifocality. Receiver operating characteristic (ROC) analysis showed AUCs below 0.8 for all candidate biomarkers. However, significant changes in the expression of all analyzed miRNAs and TSHR methylation levels indicate their potential to differentiate PTC patients from healthy individuals. These findings suggest that miRNAs and TSHR methylation levels may serve as candidate biomarkers for early diagnosis and monitoring of PTC, with the potential to distinguish PTC patients from healthy individuals. Further research is needed to validate these biomarkers for clinical application.

Study of anticancer effects of platinum levetiracetam and levetiracetam via cancer biomarkers genes expression on HepG2 cell line.

BACKGROUND: High expression of some anticancer biomarkers such as telomerase and B cell lymphoma-2(Bcl-2), microRNA-21(miRNA-21), and low expression FAS ligand (FASLG) are reported in many cancers. Some anticancer drugs such as Levetiracetam(Lev) produce their effects via the change of expression of these biomarkers. The present study aimed to evaluate the anti-cancer effects of a new compound, Platinum Levetiracetam(Pt-Lev), gene expression of mentioned biomarkers on hepatocyte G2 (HepG2) cells compared to Lev. METHODS AND RESULTS: In this study, Human Dermal fibroblast cells (HDF) were used as the negative control group (group A) HepG2 cells were divided into three groups: untreated cancer cells as positive group (group B), groups C and D were treated with, Lev and Pt-Lev, respectively. After evaluating lethal concentration 50% (LC50) for the examined drugs using the MTT test, biomarker gene expression was evaluated by real-time PCR. No Apoptotic cell was found in groups C or D before drug treatment, but it was present using different concentrations of the drugs. Results indicated that telomerase and miRNA-21 genes expression was significantly lower and FASLG was higher in group D compared with group C but there was no significant difference for Bcl-2 expression between these two groups. CONCLUSIONS: For the first time, it was indicated that Pt-Lev has anticancer effects by inhibiting telomerase and Bcl-2 and miRNA-21 and increasing FASLG gene expression and its effects were more than Lev. It effectively exerted its anticancer effects by extending apoptosis on HepG2 cells.

Serum miRNA-21, miRNA-146a and plasma cell free DNA as novel biomarkers for assessing systemic lupus erythematosus activity.

BACKGROUND: MicroRNA and cell-free DNA have shown significant correlations with several autoimmune disorders including systemic lupus erythematosus (SLE). SLE has been associated with challenges in determining its activity, so that the need for biomarkers contributing to assessing its activity is emerging. The current study investigated miRNA-21, miRNA-146a and plasma cf-DNA in determination of SLE activity, in addition their association with clinical data including complement factor 3 (C3), complement factor(C4), anti-dsDNA, and other disease activity indices. METHODS AND RESULTS: Eighty subjects divided into; twenty active patients (with SLE-DAI2K score of 16-18) twenty inactive patients (with SLE-DAI2K score of 1-3), and forty healthy control participants) were included in this study. Serum miR-21, miR-146a, and plasma cf-DNA were quantified by real time PCR and their correlation with clinical data was statistically analyzed. The results demonstrated that active cases have significant upregulation of serum miRNA-21 and plasma cf-DNA. Moreover, miR-21 showed a negative, significant pertaining to C3, C4 and was positively related to Systemic Lupus Erythematosus Disease Activity Index 2 K score (SLE-DAI Index2K score) and Systemic-Lupus-Erythematosus-Disease Activity-Index 2 K activity (SLE-DAI 2 K activity). Also, Active group miRNA-146a was negatively, significantly correlated with C3, as well as a positive significant relationship with SLE-DAI2K score and SLEDAI 2 K activity, in addition to anti DNA Autoantibodies. Furthermore, miR-21 and cf-DNA demonstrated a differential value through Receiver Operating Characteristic (ROC) curve's study. CONCLUSIONS: the present study illustrated miR-21, miR-146a, and cf-DNA relationship with SLE clinical data. In addition to their potential value in SLE diagnosis, and activity determination.

MiRNA-21-5p Accelerates EMT and Inhibits Apoptosis of Laryngeal Carcinoma via Inhibiting KLF6 Expression.

The incidence of laryngeal carcinoma accounts for 1 to 5% of systemic malignancies and ranks second among head and neck malignancies. Screening more effective targets are meaningful for the treatment of laryngeal carcinoma. The purpose was to research the action of miR-21-5p in the occurrence of laryngeal carcinoma. Genecards combined with g:profiler was used for cluster analysis to predict gene-related miRNAs. Q-PCR assay was performed for measuring the level of miR-21-5p and Kruppel-like factor 6 (KLF6). miR-21-5p-mimic, miR-21-5p-inhibitor and sh-KLF6 were transfected using LipofectamineTM 2000. Both CCK-8 and EdU experiments were undertaken to detect cell proliferation ability. Western blot was used to detect apoptosis and epithelial-mesenchymal transition (EMT) related proteins. Wound healing assay and transwell assay were undertaken for migration and invasion, respectively. Three online software (ENCORI, miRWalk, and miRDB) were applied to screen the downstream of miR-21-5p. At the same time, a dual-luciferase reporter experiment was processed to verify the binding. Finally, a rescue experiment was applied to reveal the mediating role of miR-21-5p and KLF6. MiR-21-5p expressed highly in laryngeal carcinoma tissues and cell lines. Knockdown of miR-21-5p reduced the EMT, while enhancing apoptosis of laryngeal carcinoma cell lines. MiR-21-5p targeted KLF6 with negative relationships. The rescue assay results confirmed that sh-KLF6 rescued the action of miR-21-5p knockdown in developing laryngeal carcinoma cells. MiR-21-5p promotes the occurrence and development of laryngeal cancer by targeting KLF6. This finding may provide new insights into miRNA as a biomarker for diagnosing and treating laryngeal carcinoma in the future.

Exosomal miRNAs contribute to coal dust particle-induced pulmonary fibrosis in rats.

Coal workers' pneumoconiosis (CWP) is a fatal occupational disease caused by inhalation of coal dust particles, which leads to progressive pulmonary fibrosis. Recently, as new signal carriers for intercellular communication, exosomal miRNAs have been validated in the pathogenesis of multiple diseases. However, the research on exosomal miRNAs in CWP is still in the preliminary stage. Here, using miRNA sequencing, exosomal miRNA profiles in bronchoalveolar lavage fluid (BALF) from rats with pulmonary fibrosis induced by coal dust particles were analyzed, and the underlying biological function of putative target genes was explored by GO term analysis and KEGG pathway enrichment analysis. According to the results, intratracheal instillation of coal dust particles can alter the exosomal miRNAs expression in the BALF of rats. Further bioinformatics analysis provided some clues to reveal their function in pathological process of pneumoconiosis. More importantly, we identified 4 differentially expressed exosomal miRNAs (miRNA-21-5p, miRNA-29a-3p, miRNA-26a-5p, and miRNA-34a-5p) by qRT­PCR and further verified the temporal changes in the expression of these exosomal miRNAs in animal models from 2 weeks to 16 weeks postexposure. In addition, we conducted a preliminary study on Smad7 as a potential target of miRNA-21-5p and found that exosomal miRNA 21-5p/Smad7 may contribute to the pulmonary fibrosis induced by coal dust particles. Our study confirmed the contribution of exosomal miRNAs to coal dust particle-induced pulmonary fibrosis and provided new insights into the pathogenesis of CWP.

Multiorbital DNA walker nanoprobe for portable photothermal detection based on H2S etching of cubic Prussian blue.

In the developed assay, multiorbital 3D DNA walker (MO DNA walker) was applied as signal amplified protocol for enhancing the detection signal of the photothermal biosensor, which was designed for sensitive detection of miRNA based on the H2S triggered conversation of photothermal reagent. When the target molecule is present, the DNA walking strand was released and then hybridize with track strands. The landing of walking particles (WPT) on the tracking particles (TPT) promotes the relative movement of the WPT around TPT, thus releasing large amount of horseradish peroxidase (HRP) with the aid of DNAzyme. After reacting with Na2S2O3 and H2O2, multiple H2S can be generated in situ based on the catalytic ability of HRP. Meanwhile, cubic Prussian blue (CPB) was synthesized and exhibited superior photothermal response, which can be served as efficient photothermal reagent and H2S responsive acceptor. Significantly, the photothermal signal of CPB could be obviously reduced after challenged with H2S ascribed to synchronous reaction between the ferric ion (Fe3+) and H2S. The improved walking area and freedom enable significant signal amplification, enhancing the biosensor's performance. Under ideal circumstances, the proposed photothermal assay demonstrated excellent performance for determination of miRNA-21.

An electrochemical determination strategy for miRNA based on bimetallic nanozyme and toehold-mediated DNA replacement procedure.

An electrochemical strategy based on bimetallic nanozyme in collaboration with toehold-mediated DNA replacement effect is proposed for the sensitive determination of miRNA-21. The AuPt nanoparticles (AuPt NPs) are prepared as a catalytic beacon; it shows favorable peroxidase properties with a Michaelis contant (Km) of 0.072 mM for H2O2, which is capable of catalyzing H2O2 to induce an intense redox reaction, and causing a measurable electrochemical signal. To further enhance the strength of the signal response, a novel toehold-mediated DNA replacement strategy is employed. DNA strands with specific sequences are modified on electrodes and AuPt NPs, respectively. In the presence of miRNA-21, a cyclic substitution effect is subsequently activated via a specific toehold sequence and leads to a large accumulation of AuPt NPs on the electrodes. Subsequently, a strong signal depending on the amount of miRNA-21 is obtained after adding a small amount of H2O2. The analytical range of this determination method is from 0.1 pM to 1.0 nM, and the LOD is 84.1 fM. The spike recoveries for serum samples are 95.0 to 102.4% and the RSD values are 3.7 to 5.8%. The results suggests a promising application of the established method in clinical testing and disease diagnosis.

Ti3C2@Bi2O3 nanoaccordion for electrochemical determination of miRNA-21.

Based on a dual signal amplification strategy of novel accordion-like Bi2O3-decorated Ti3C2 (Ti3C2@Bi2O3) nanocomposites and hybridization chain reaction (HCR), an ultra-sensitive electrochemical biosensor was constructed for miRNA-21 detection. By etching Ti3AlC2 with HF, Ti3C2 with an accordion-like structure was first obtained and subsequently covered by Bi2O3 nanoparticles (NPs), forming Ti3C2@Bi2O3. A layer of Au NPs was electrodeposited on the glassy carbon electrode coated with Ti3C2@Bi2O3, which not only significantly improved the electron transport capacity of the electrode but also greatly increased its surface active area. Upon the immobilization of the thiolated capture probe (SH-CP) on the electrode, the target miRNA-21 specifically hybridized with SH-CP and thus opened its hairpin structure, triggering HCR to form a long double strand with the primers H1 and H2. A large number of the electrochemical indicator molecules were thus embedded inside the long double strands to produce the desirable electrochemical signal at a potential of - 0.19 V (vs. Ag/AgCl). Such dual signal amplification strategy successfully endowed the biosensor with ultra-high sensitivity for miRNA-21 detection in a wide linear range from 1 fM to 100 pM with a detection limit as low as 0.16 fM. The excellent detection of miRNA-21 in human blood plasma displayed a broad prospect in clinical diagnosis. An ultra-sensitive electrochemical biosensor was successfully constructed for miRNA-21 detection in human blood plasma based on the dual signal amplification strategy of novel accordion-like Bi2O3 decorated Ti3C2 (Ti3C2@Bi2O3) nanocomposites and hybridization chain reaction.

Mn-MOF catalyzed multi-site atom transfer radical polymerization electrochemical sensing of miRNA-21.

A green electrochemical biosensor was developed based on metal-organic framework (MOF)-catalyzed atom transfer radical polymerization (ATRP) for quantifying miRNA-21, used as the proof-of-concept analyte. Unlike conventional ATRP, Mn-PCN-222 (PCN, porous coordination network) could be used as an alternative for green catalyst to substitute traditional catalysts. First, poly (diallyldimethylammonium chloride) (PDDA) was fixed on the surface of the indium tin oxide (ITO) electrode, and then the Mn-PCN-222 was linked to ITO electrode via electrostatic binding with PDDA. Next, aminated ssDNA (NH2-DNA) was used to modify the electrode further by amide reaction with Mn-PCN-222. Then, the recognition and hybridization of NH2-DNA with miRNA-21 prompt the generation of DNA-RNA complexes, which further hybridize with Fc-DNA@ß-CD-Br15 and permit the initiator to be immobilized on the electrode surface. Accordingly, ß-CD-Br15 could initiate the polymerization of ferrocenylmethyl methacrylates (FcMMA) under the catalysis of MOF to complete the ATRP reaction. FcMMA presented a distinct electrochemical signal at ~ 0.33 V. Taking advantage of the unique multi-site properties of ß-CD-Br15 and the efficient catalytic reaction induced by Mn-PCN-222, ultrasensitive detection of miRNA-21 was achieved with a detection limit of 0.4 fM. The proposed electrochemical biosensor has been applied to the detection of miRNA-21 in serum samples. Therefore, the proposed strategy exhibited potential in early clinical biomedicine.

Osteogenic and Adipogenic Differentiation Potential of Oral Cancer Stem Cells May Offer New Treatment Modalities.

(1) Treatment failure of oral squamous cell carcinoma (OSCC) is generally due to the development of therapeutic resistance caused by the existence of cancer stem cells (CSCs), a small cell subpopulation with marked self-renewal and differentiation capacity. Micro RNAs, notably miRNA-21, appear to play an important role in OSCC carcinogenesis. Our objectives were to explore the multipotency of oral CSCs by estimating their differentiation capacity and assessing the effects of differentiation on stemness, apoptosis, and several miRNAs' expression. (2) A commercially available OSCC cell line (SCC25) and five primary OSCC cultures generated from tumor tissues obtained from five OSCC patients were used in the experiments. Cells harboring CD44, a CSC marker, were magnetically separated from the heterogeneous tumor cell populations. The CD44+ cells were then subjected to osteogenic and adipogenic induction, and the specific staining was used for differentiation confirmation. The kinetics of the differentiation process was evaluated by qPCR analysis of osteogenic (Bone Morphogenetic Protein-BMP4, Runt-related Transcription Factor 2-RUNX2, Alkaline Phosphatase-ALP) and adipogenic (Fibroblast Activation Protein Alpha-FAP, LIPIN, Peroxisome Proliferator-activated Receptor Gamma-PPARG) markers on days 0, 7, 14, and 21. Embryonic markers (Octamer-binding Transcription Factor 4-OCT4, Sex Determining Region Y Box 2-SOX2, and NANOG) and micro RNAs (miRNA-21, miRNA-133, and miRNA-491) were also correspondingly evaluated by qPCR. An Annexin V assay was used to assess the potential cytotoxic effects of the differentiation process. (3) Following differentiation, the levels of markers for the osteo/adipo lineages showed a gradual increase from day 0 to day 21 in the CD44+ cultures, while stemness markers and cell viability decreased. The oncogenic miRNA-21 also followed the same pattern of gradual decrease along the differentiation process, while tumor suppressor miRNA-133 and miRNA-491 levels increased. (4) Following induction, the CSCs acquired the characteristics of the differentiated cells. This was accompanied by loss of stemness properties, a decrease of the oncogenic and concomitant, and an increase of tumor suppressor micro RNAs.

Differential regulation of miR-21-5p delays wound healing of melanocyte-deprived vitiligo skin by modulating the expression of tumor-suppressors PDCD4 and Maspin.

The loss of melanocytes in vitiligo is associated with architectural, transcriptional, and cellular perturbations of keratinocytes and manifests as a reduced proliferation potential in vitro and delayed re-epithelialization in vivo. To understand the molecular mechanisms underlying this delay, microRNA (miRNA) profiling was performed on split skin biopsies collected on Day 1 (basal level) and Day 14 (wound re-epithelialization) from nonlesional (NL) and lesional (L) skin of five subjects with stable nonsegmental vitiligo and 129 miRNAs were found to be differentially regulated between the NL and L healed epidermis. miR-21-5p, expressed at comparable levels on NL and L Day 1 samples, demonstrated significant upregulation during re-epithelialization. However, the extent of its upregulation was relatively lower in L (10 times compared to Day 1) as compared to NL skin (17 times compared to Day 1). The overexpression of miR-21 in keratinocytes led to a significant increase in the expression of proliferation markers (Ki67 and MCM6 messenger RNA, Ki67 positivity), along with an increase in keratinocyte migration. Using a small interfering RNA mediated knockdown approach, we further demonstrated that miR-21-5p mediates its effects by suppressing the expression of programmed cell death 4 (PDCD4) and mammary serine protease inhibitor (Maspin), both tumor-suppressor genes. Investigation of clinical samples corroborated the lower miR-21 levels and a higher expression of PDCD4 and Maspin in L Day 14 compared to the NL Day 14 epidermis. In conclusion, this study revealed that a relatively lower upregulation of miR-21-5p in L skin leads to significantly higher levels of PDCD4 and Maspin, delaying wound re-epithelialization by reducing the proliferation and migration of keratinocytes.

Ginsenoside Rh2 Ameliorates Neuropathic Pain by inhibition of the miRNA21-TLR8-mitogen-activated protein kinase axis.

Ginsenoside Rh2 is one of the major bioactive ginsenosides in Panax ginseng. Although Rh2 is known to enhance immune cells activity for treatment of cancer, its anti-inflammatory and neuroprotective effects have yet to be determined. In this study, we investigated the effects of Rh2 on spared nerve injury (SNI)-induced neuropathic pain and elucidated the potential mechanisms. We found that various doses of Rh2 intrathecal injection dose-dependently attenuated SNI-induced mechanical allodynia and thermal hyperalgesia. Rh2 also inhibited microglia and astrocyte activation in the spinal cord of a murine SNI model. Rh2 treatment inhibited SNI-induced increase of proinflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-1 and IL-6. Expression of miRNA-21, an endogenous ligand of Toll like receptor (TLR)8 was also decreased. Rh2 treatment blocked the mitogen-activated protein kinase (MAPK) signaling pathway by inhibiting of phosphorylated extracellular signal-regulated kinase expression. Finally, intrathecal injection of TLR8 agonist VTX-2337 reversed the analgesic effect of Rh2. These results indicated that Rh2 relieved SNI-induced neuropathic pain via inhibiting the miRNA-21-TLR8-MAPK signaling pathway, thus providing a potential application of Rh2 in pain therapy.

Schwann cell reprogramming into repair cells increases miRNA-21 expression in exosomes promoting axonal growth.

Functional recovery after peripheral nerve damage is dependent on the reprogramming of differentiated Schwann cells (dSCs) into repair Schwann cells (rSCs), which promotes axonal regeneration and tissue homeostasis. Transition into a repair phenotype requires expression of c-Jun and Sox2, which transcriptionally mediates inhibition of the dSC program of myelination and activates a non-cell-autonomous repair program, characterized by the secretion of neuronal survival and regenerative molecules, formation of a cellular scaffold to guide regenerating axons and activation of an innate immune response. Moreover, rSCs release exosomes that are internalized by peripheral neurons, promoting axonal regeneration. Here, we demonstrate that reprogramming of Schwann cells (SCs) is accompanied by a shift in the capacity of their secreted exosomes to promote neurite growth, which is dependent on the expression of c-Jun (also known as Jun) and Sox2 by rSCs. Furthermore, increased expression of miRNA-21 is responsible for the pro-regenerative capacity of rSC exosomes, which is associated with PTEN downregulation and PI3-kinase activation in neurons. We propose that modification of exosomal cargo constitutes another important feature of the repair program of SCs, contributing to axonal regeneration and functional recovery after nerve injury.

Ultrasensitive, rapid, and highly specific detection of microRNAs based on PER-CRISPR/CAS.

Abnormal microRNA (miRNA) expression levels are confirmed as diagnostic biomarkers of the emergence and development of diseases. In this study, we developed a fluorescence biosensor for detecting miRNAs based on double amplification reactions with the primer exchange reaction (PER) and CRISPR/Cas12a. In the absence of target miRNA-21, PER hairpins remained locked by the protector strands and the primers did not extend. In the presence of target miRNA-21, the miRNA-21 bound to the guard sequence and exposed primer binding sites. Also, the closed PER hairpin was unlocked to specifically extend primers into single-stranded DNA (ssDNA) of unequal lengths. These ssDNAs of unequal lengths could activate the cleavage of a reporter by Cas12a, leading to an increase in detectable fluorescence signals. A large number of short nucleic acid fragments were amplified by PER-CRISPR multiple cycle cleavage fluorescent probes. Based on PER-combined CRISPR/Cas12a established dual signal amplification method was characterized by a low limit of detection of 10fM. The fluorescent biosensor for miRNA detection had the advantages of low detection cost, simple operation, and mobility, providing a very promising platform for the point-of-care testing of miRNA-21.

Evaluation of miRNA-21-5p and miRNA-10b-5p levels in serum-derived exosomes of breast cancer patients in different grades.

BACKGROUND & OBJECTIVES: Tumor cells have various effects and dominance over other healthy cells. Cancer cells alter the cell program in healthy cells by secreting exosomes containing microRNAs involved in epithelial-mesenchymal transition (EMT). They can migrate to distant organs and establish a pre-metastatic niche. The purpose of this study was to determine the expression of miRNA-21-5p and miRNA-10b-5p, both of which are involved in EMT, in breast cancer-derived exosomes of various grades in order to identify new biomarkers involved in breast cancer progression. METHODS: In this study, a blood sample was taken from 60 patients with grades I, II, or III breast cancer, as well as twenty healthy individuals as a control group. The exosomes were then purified from serum samples, and their relative expression of miRNA-21-5p and miRNA-10b-5p was determined using the real-time PCR method. RESULTS: miRNA-21-5p expression was significantly increased in patients with breast cancer grades I, II, and III compared to the control group (p < 0.01), (p < 0.0001) and (p < 0.0001), respectively, as was miRNA-10b-5p expression in patients with breast cancer grades I, II, and III compared to the control group (p < 0.0001), (p < 0.0001) and (p < 0.0001), respectively. CONCLUSION: Our results show that both microRNAs increase as cells lose their differentiation and become more invasive, which is evidence of cancer progression. Hence, both microRNAs may have the potential to be used alone or in combination with other biomarkers for the diagnosis and prognosis of breast cancer.

DNAzyme signal amplification based on Au@Ag core-shell nanorods for highly sensitive SERS sensing miRNA-21.

Here, we developed a surface-enhanced Raman scattering (SERS) sensor based on functionalized Au@Ag core-shell nanorods (Au@Ag NRs) and cascade DNAzyme amplifier (CSA) for sensitive and accurate determination of microRNA-21 (miRNA-21). The as-prepared SERS nanoprobes were composed of a thiol-modification hairpin probe (HP2)-functionalized Au@Ag NRs and hairpin DNAzyme (HP1-Dz). Compared with original gold nanorods, the silver shell caused an enhancement of plasmonic properties, resulting in a significant enhancement of Raman signals. In the presence of target miRNAs, the hairpin construction of HP1-Dz changed due to DNA/RNA hybridization; subsequently, the DNAzyme-catalyzed cleaving process changed, and the Raman signals of the SERS nanoprobes gradually "turned off" with time elapse because of the dissociation of the Raman reporter from the surface of Au@Ag NRs. Hence, based on this principle, the proposed SERS sensor exhibited good linearity in the range 0.5 fM to 10 nM for miRNA-21 detection with a detection limit (LOD) of 0.5 fM. The proposed SERS platform has potential application in quantitative and precise detection of miRNA-21 in human serum.

Identification of osteosarcoma by microRNA-coupled nuclease digestion on interdigitated electrode sensor.

Osteosarcoma is a type of tumor originating from the bone cells, most often from long bones. Children and adolescents are mainly affected by osteosarcoma. Identifying the condition with osteosarcoma is mandatory to provide proper treatment to the affected patients. This research work has introduced an identification of an osteosarcoma biomarker "miRNA-21" on the interdigitated electrochemical sensor by nuclease digestion. The target RNA sequence of miRNA-21 was hybridized to the capture DNA and placed on the sensing electrode surface with the aid of the biotin-streptavidin interaction. The unhybridized immobilized single-standard capture DNA was digested by S1-nuclease. The current response of the digestion level was considered as the duplex formation between the target and capture DNA. Using this technique, the detection limit of the target was reached to 1 fM and a similar response of current was noted with the target RNA-spiked human serum, indicating the selective identification of target RNA. Further, single mismatched, triple mismatched, and random miRNA sequences (miRNA-195) failed to interact with the immobilized capture DNA, representing the specific identification of target RNA. This nuclease digestion technique with miRNA-21 identification helps in detecting osteosarcoma and related issues.