800 research outputs found

    Expressions and clinic significance of miRNA-143, miRNA- 34A, miRNA-944, miRNA-101 and miRNA-218 in cervical cancer tissues

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    Purpose: To search for novel biomarkers for early diagnosis of cervical cancer, as well as novel therapeutic target for cervical cancer.Methods: A total of 96 cervical tissue specimens were collected from patients in the Second Affiliated Hospital of Zhengzhou University, out of which 10 were normal control. The remaining specimens (86) were cervical cancer specimens and were divided into 4 groups (A - D) based on tumor-biomarker levels of CA125 and SCC. Quantitative real-time polymerase chain reaction technology (qRT-PCR) was used to detect the expressions of miRNA-143, miRNA-34A, miRNA-944, miRNA-101 and miRNA-218 in the cervical cancer tissues.Results: The levels of CA125 (U/mL) and SCC (ug/L) expressed in normal control group and groups A - D were 11.75 and 0.73 (n = 10), 382 and 2.72 (n = 25), 912.9 and 3.93 (n = 21), 1675 and 5.87 (n = 29), and 2120 and 6.66 (n = 11), respectively. Furthermore, qRT-PCR results showed that the expressions of miRNA-944 and miRNA-218 in cervical cancer tissues were markedly up-regulated compared to normal control tissues (p < 0.01). In contrast, the expression level of miRNA-143, miRNA-34A, and miRNA-101 were significantly decreased (p < 0.01).Conclusion: The biomarkers, miRNA-143, miRNA-34A, miRNA-944, miRNA-101 and miRNA-218, can be considered novel for early diagnosis of cervical cancer.Keywords: Cervical cancer, Biomarkers, miRNA-143, miRNA-34A, miRNA-944, miRNA-101, miRNA- 21

    Long non-coding RNA HOTAIR drives EZH2-dependent myofibroblast activation in systemic sclerosis through miRNA 34a-dependent activation of NOTCH

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    Background Systemic sclerosis (SSc) is characterised by autoimmune activation, tissue and vascular fibrosis in the skin and internal organs. Tissue fibrosis is driven by myofibroblasts, that are known to maintain their phenotype in vitro, which is associated with epigenetically driven trimethylation of lysine 27 of histone 3 (H3K27me3). Methods- Full-thickness skin biopsies were surgically obtained from the forearms of 12 adult patients with SSc of recent onset. Fibroblasts were isolated and cultured in monolayers and protein and RNA extracted. HOX transcript antisense RNA (HOTAIR) was expressed in healthy dermal fibroblasts by lentiviral induction employing a vector containing the specific sequence. Gamma secretase inhibitors were employed to block Notch signalling. Enhancer of zeste 2 (EZH2) was blocked with GSK126 inhibitor. Results- SSc myofibroblasts in vitro and SSc skin biopsies in vivo display high levels of HOTAIR, a scaffold long non-coding RNA known to direct the histone methyltransferase EZH2 to induce H3K27me3 in specific target genes. Overexpression of HOTAIR in dermal fibroblasts induced EZH2-dependent increase in collagen and α-SMA expression in vitro, as well as repression of miRNA-34A expression and consequent NOTCH pathway activation. Consistent with these findings, we show that SSc dermal fibroblast display decreased levels of miRNA-34a in vitro. Further, EZH2 inhibition rescued miRNA-34a levels and mitigated the profibrotic phenotype of both SSc and HOTAIR overexpressing fibroblasts in vitro. Conclusions- Our data indicate that the EZH2-dependent epigenetic phenotype of myofibroblasts is driven by HOTAIR and is linked to miRNA-34a repression-dependent activation of NOTCH signalling

    Multimodal layer-by-layer nanoparticles: a breakthrough in gene and drug delivery for osteosarcoma

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    \ua9 2024 The Royal Society of Chemistry. Osteosarcoma is one of the most common primary malignant bone tumours in children and adolescents, frequently arising from mesenchymal tissue in the distal femur. It is highly aggressive, often metastasising to the lungs. Current treatments, which include surgery combined with neoadjuvant chemotherapy and radiotherapy, are often unsatisfactory due to the inability of surgery to control metastasis and the side effects and drug resistance associated with chemotherapy. Thus, there is an urgent need for new treatment technologies. This study explored the use of nanoparticles for gene and drug delivery in osteosarcoma treatment. The nanoparticles were composed of biodegradable and biocompatible polymers, chitosan and PLGA, and were loaded with miRNA-34a, a short RNA molecule that functions as a tumour suppressor by inducing cell cycle arrest and apoptosis in osteosarcoma cells. Recognising that the co-delivery of multiple drugs can enhance treatment efficacy while reducing systemic toxicity and drug resistance, three additional classes of nanoparticles were developed by adding doxorubicin and resveratrol to the chitosan-PLGA-miRNA-34a core. A layer-by-layer technique was employed to create a bilayer nanocoating using pectin and chitosan as polyelectrolytes, for encapsulating the therapeutic payloads. The manufactured nanoparticles were tested on U2OS and Saos-2 cells to assess cell viability, metabolic activity, and morphology before and after treatment. Cells were treated in both two-dimensional cultures and three-dimensional osteosarcoma spheroids, creating a biomimetic cellular model. Increased apoptotic activity and disruption of cellular functions were primarily observed with nanoparticles co-delivering miRNA-34a and drugs, particularly those functionalised with the LbL nanocoating, as confirmed by PCR analysis

    Oxidative stress dependent microRNA-34a activation via PI3Kα reduces the expression of sirtuin-1 and sirtuin-6 in epithelial cells

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    Sirtuin-1 (SIRT1) and SIRT6, NAD(+)-dependent Class III protein deacetylases, are putative anti-aging enzymes, down-regulated in patients with chronic obstructive pulmonary disease (COPD), which is characterized by the accelerated ageing of the lung and associated with increased oxidative stress. Here, we show that oxidative stress (hydrogen peroxide) selectively elevates microRNA-34a (miR-34a) but not the related miR-34b/c, with concomitant reduction of SIRT1/-6 in bronchial epithelial cells (BEAS2B), which was also observed in peripheral lung samples from patients with COPD. Over-expression of a miR-34a mimic caused a significant reduction in both mRNA and protein of SIRT1/-6, whereas inhibition of miR-34a (antagomir) increased these sirtuins. Induction of miR-34a expression with H2O2 was phosphoinositide-3-kinase (PI3K) dependent as it was associated with PI3Kα activation as well as phosphatase and tensin homolog (PTEN) reduction. Importantly, miR-34a antagomirs increased SIRT1/-6 mRNA levels, whilst decreasing markers of cellular senescence in airway epithelial cells from COPD patients, suggesting that this process is reversible. Other sirtuin isoforms were not affected by miR-34a. Our data indicate that miR-34a is induced by oxidative stress via PI3K signaling, and orchestrates ageing responses under oxidative stress, therefore highlighting miR-34a as a new therapeutic target and biomarker in COPD and other oxidative stress-driven aging diseases

    Shedding light on miRNA targeting through structure

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    In miRNAs, it is known that seed pairing is an important parameter for targeting, but there are still missing links on why it targets a certain mRNA and how the decision between degradation or translation repression is made. In our work, we use liquid state NMR spectroscopy, EMSA and UV melting experiments to biophysically characterise the complex of miRNA-34a with the target mRNA of CD44 and PNUTS. Here we present the NMR sample preparation as well as the first steps for the biophysical description of the mRNA.miRNA complexes. Our EMSA data suggests both miRNA.mRNA complexes are transient and miRNA.gCD44 possibility has a higher Kd then miRNA.PNUTS. Through NMR miRNA.PNUTS complex was deemed more structurally dynamic, yet interestingly with UV melting it had a higher Tm then miRNA.gCD44 complex. Finally, we also performed several simulations on several different mRNA targets with MCFold unveiling a kink on the mRNA as a structural trend which could be a necessity for docking of the duplex into Ago. Still further studies must be conducted in order to solve the structures of both duplexes in study and a bigger population of simulated structures must be collected

    Investigating the relationship between miRNA expression and epithelial mesenchymal transition in colorectal cancer

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    Introduction: Epithelial-mesenchymal transition (EMT) is characterized by the loss of an epithelial phenotype and gain of a mesenchymal phenotype, i.e., migratory and metastatic properties. The EMT process is therefore characterized by a low expression of E-cadherin and high expression of mesenchymal markers (e.g., N-cadherin, snail and vimentin). It is stated that cells which have undergone EMT also gain stem cell features. Therefore, both EMT and stem cell phenotypes have been implicated in carcinogenesis and metastasis of tumour cells. Furthermore, EMT is regulated by small non-coding molecules (miRNAs) that either function as tumour suppressors or oncogenes (oncomirs). Tumour suppressor miRNAs reverse EMT while oncomirs activate it. Therefore, investigating the relationship between miRNAs and EMT is important in addressing metastasis of colorectal cancers (CRC). Aims and Objectives: The aim of the study was to determine the association between miRNA (miRNA-21 and miRNA-34a) expression levels and EMT in CRC. In addition, this investigation aimed to correlate miRNA and EMT data with clinicopathologic features of the study cohort. Methodology: A total of 100 CRC (including 8 known HNPCC cases) Formalin Fixed Paraffin Embedded (FFPE) tissue blocks and their corresponding H&E slides were collected from the archives of the Division of Anatomical Pathology at the University of Cape Town. Subsequently, the FFPE tissue blocks were sectioned at 3μm and IHC analysis of 4 EMT markers (E-cadherin, N-cadherin, snail-1 and vimentin) and 1 stem cell marker (CD44V6) was performed. The stains were then evaluated and scored by a pathologist. The IHC data were then correlated with clinicopathologic features. Furthermore, 59 cases (FFPE tissues and corresponding H&E slides) which included the 8 HNPCCs were randomly selected for miRNA analysis. The H&Es were examined by a pathologist to demarcate normal and tumour regions. RNA was then extracted from 59 tumours and 12 normal tissues using a High Pure FFPET Isolation Kit (Roche). Subsequently, cDNA was synthesized and qRT-PCR was performed to determine the expression levels of miRNA-21 and miRNA-34a. MiRNA-21 and miRNA-34a expression levels were ascertained using the relative quantification method. Moreover, the clinical significance of the two miRNAs was evaluated in relation to MSI status. Therefore, IHC analysis of MLH1, MSH2 and MSH6 mismatch repair proteins was performed on the Ventana platform. Statistical analysis was performed using Fisher's and Pearson's Chi Square tests in Stata 12 to correlate EMT and clinicopathologic data. Additionally, the Mann-Whitney non-parametric test in GraphPad prism 6 was used to determine miRNA-21 and miRNA-34a expression in relation to EMT and MSI data. Results: Our results showed low expression of E-cadherin in 77% of cases. In addition, there was decreased expression of N-cadherin and vimentin in 98% whilst snail-1 expression was decreased in 65% of the cases. Low expression of CD44v6 was also seen in 78% of the cases. There was no correlation between EMT/stem cell markers and clinicopathologic data. Furthermore, increased miRNA-21 expression was significantly associated with grade, lymph node metastasis and age of patients. There was a significant correlation between high miRNA- 21 expression and down-regulated snail-1 and N-cadherin expression. MiRNA-34a expression was not associated with any of the clinicopathologic features. In addition, high miRNA-34a expression was linked with low expression of snail-1 and CD44v6. Increased miRNA-21 expression was related with MSS tumours, whereas there was no relationship between miRNA- 34a and MSI status. Conclusion: Our investigation shows that there is an inverse association between miRNA (miRNA-21 and miRNA-34a) expression and two EMT (N-cadherin and snail-1) markers in our colorectal cancer cohort. Our data also show that both miRNA-21 and miRNA-34a cannot be used as biomarkers to determine progression of the cancer. Contrary to previous studies, our findings indicate that miRNA-21 does not activate EMT in this CRC cohort. However, similar to other studies our results confirm that miRNA-34a may be repressing snail-1 expression, thereby inhibiting EMT in the cancer

    miR-34a: a new player in the regulation of T cell function by modulation of NF-κB signaling

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    NF-κB functions as modulator of T cell receptor-mediated signaling and transcriptional regulator of miR-34a. Our in silico analysis revealed that miR-34a impacts the NF-κB signalosome with miR-34a binding sites in 14 key members of the NF-κB signaling pathway. Functional analysis identified five target genes of miR-34a including PLCG1, CD3E, PIK3CB, TAB2, and NFΚBIA. Overexpression of miR-34a in CD4+ and CD8+ T cells led to a significant decrease of NFΚBIA as the most downstream cytoplasmic NF-κB member, a reduced cell surface abundance of TCRA and CD3E, and to a reduction of T cell killing capacity. Inhibition of miR-34a caused an increase of NFΚBIA, TCRA, and CD3E. Notably, activation of CD4+ and CD8+ T cells entrails a gradual increase of miR-34a. Our results lend further support to a model with miR-34a as a central NF-κB regulator in T cells

    Circulating MicroRNAs as a Tool for Diagnosis of Liver Disease Progression in People Living with HIV-1

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    MicroRNAs (miRNAs) are small, non-coding RNAs that post-transcriptionally regulate gene expression by binding specific cell mRNA targets, preventing their translation. miRNAs are implicated in the regulation of important physiological and pathological pathways. Liver disease, including injury, fibrosis, metabolism dysregulation, and tumor development disrupts liver-associated miRNAs. In addition to their effect in the originating tissue, miRNAs can also circulate in body fluids. miRNA release is an important form of intercellular communication that plays a role in the physiological and pathological processes underlying multiple diseases. Circulating plasma levels of miRNAs have been identified as potential disease biomarkers. One of the main challenges clinics face is the lack of available noninvasive biomarkers for diagnosing and predicting the different stages of liver disease (e.g., nonalcoholic fatty liver disease and nonalcoholic steatohepatitis), particularly among individuals infected with human immunodeficiency virus type 1 (HIV-1). Liver disease is a leading cause of death unrelated to acquired immunodeficiency syndrome (AIDS) among people living with HIV-1 (PLWH). Here, we review and discuss the utility of circulating miRNAs as biomarkers for early diagnosis, prognosis, and assessment of liver disease in PLWH. Remarkably, the identification of dysregulated miRNA expression may also identify targets for new therapeutics
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