CircPAN3/miR-221/PTEN axis and apoptosis in myocardial Infarction: Quercetin's regulatory effects

The circular RNA/microRNA/mRNA axis is a new layer of non-coding RNA(ncRNA)-based regulatory gene expression networks upstream of numerous cell signaling pathways. Circular RNAPAN3 (circPAN3) is involved in autophagy, fibrosis and apoptosis which are responsible for the reduction incardiac functional capacityfollowingmyocardial infarction(MI). However, the molecular mechanism of circPAN3 association with apoptosis is unknown. In addition, the relationship between quercetin as a cardioprotective factor in MI and circular RNA-dependent regulatory pathways has not yet been elucidated. MI was induced in Wistar rats using the left anterior descending artery (LAD) ligation method. One day after surgery, quercetin (30 mg/kg) was injected intraperitoneal (IP) every other day for two weeks. The expression of circPAN3 was increased in the MI group (P < 0.05). The increase in circPAN3 was accompanied by a decrease in miR-221 (P < 0.0001), an increase in PTEN (P < 0.0001), and cleaved caspase 3 (P < 0.001). Quercetin effectively reduced the expression of circPAN3 (P < 0.05), PTEN (P < 0.0001), and cleaved caspase 3 (P < 0.001), and increased the expression of miR-221 (P < 0.0001) and the ratio of p-AKT to p-PI3K (P < 0.001). The circPAN3/miR-221/PTEN pathway is an ncRNA-dependent apoptotic pathway in MI cardiac tissue. Quercetin effectively modulated this pathway, resulting in a reduction of cardiac tissue death and improvement in cardiac function after MI. This suggests that the circPAN3/miR-221 axis plays a role in apoptosis in MI, and quercetin can act as a protective candidate by modulating this pathway.

Evaluating the effects of curcumin nano-chitosan on miR-221 and miR-222 expression and Wnt/β-catenin pathways in MCF-7, MDA-MB-231 and SKBR3 cell lines

BACKGROUND

Breast cancer is one of the most common diseases worldwide that affects women of reproductive age. miR-221 and miR-222 are two highly homogeneous microRNAs that play pivotal roles in many cellular processes and regulate the Wnt/β-catenin signaling pathway. Curcumin (CUR), a yellow polyphenolic compound, targets numerous signaling pathways relevant to cancer therapy. The main aim of this study was to compare the ability of chitosan curcumin nanoparticle (CC-CUR) formulation with the curcumin in modulating miR-221 and miR-222 expression through Wnt/β-catenin signaling pathway in MCF-7, MDA-MB-231 and SK-BR-3 breast cancer cell lines.

METHOD

Chitosan-cyclodextrin-tripolyphosphate containing curcumin nanoparticles (CC-CUR) were prepared. Cytotoxicity of the CUR and CC-CUR was evaluated. Experimental groups including CC-CUR, CUR and negative control were designed. The expression of miR-221 and miR-222 and Wnt/β-catenin pathway genes was measured.

RESULTS

The level of miR-221 and miR-222 and β-catenin genes decreased in MCF-7 and MDA-MB-231 cells and WIF1 gene increased in all cells in CC-CUR group. However, the results in SK-BR-3 cell line were unexpected; since miRs and WIF1 gene expressions were increased following CC-CUR administration and β-catenin decreased by administration of CUR.

CONCLUSION

Although the composite form of curcumin decreased the expression of miR-221 and miR-222 in MCF-7 and MDA cells, with significant decreasing of β-catenin and increasing of WIF1 gene in almost all three cell lines, we can conclude than this formulation exerts its effect mainly through the Wnt/β-catenin pathway. These preliminary findings may pave the way for the use of curcumin nanoparticles in the treatment of some known cancers.

miR-221 and Parkinson's disease: A biomarker with therapeutic potential

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra, leading to various motor and non-motor symptoms. Several cellular and molecular mechanisms such as alpha-synuclein (α-syn) accumulation, mitochondrial dysfunction, oxidative stress and neuroinflammation are involved in the pathogenesis of this disease. MicroRNAs (miRNAs) play important roles in post-transcriptional gene regulation. They are typically about 21-25 nucleotides in length and are involved in the regulation of gene expression by binding to the messenger RNA (mRNA) molecules. miRNAs like miR-221 play important roles in various biological processes, including development, cell proliferation, differentiation and apoptosis. miR-221 promotes neuronal survival against oxidative stress and neurite outgrowth and neuronal differentiation. Additionally, the role of miR-221 in PD has been investigated in several studies. According to the results of these studies, (1) miR-221 protects PC12 cells against oxidative stress induced by 6-hydroxydopamine; (2) miR-221 prevents Bax/caspase-3 signalling activation by stopping Bim; (3) miR-221 has moderate predictive power for PD; (4) miR-221 directly targets PTEN, and PTEN over-expression eliminates the protective action of miR-221 on p-AKT expression in PC12 cells; and (5) miRNA-221 controls cell viability and apoptosis by manipulating the Akt signalling pathway in PD. This review study suggested that miR-221 has the potential to be used as a clinical biomarker for PD diagnosis and stage assignment.

Inhibition of hepatocellular carcinoma growth via modulation of the miR-221/SOX11 axis by curcumin and berberine

Hepatocellular carcinoma (HCC) is a fatal malignancy that has limited treatment options. This study focused on the potential therapeutic effects of curcumin (CUR) and berberine (BBR) on the miR-221/SRY-box transcription factor 11 (SOX11) axis in HCC. We investigated the combined effects of CUR and BBR on HEPG2 and Huh7 cell survival and miR-221 expression using Cell Counting Kit-8 assays and RT-qPCR, respectively. Western blotting was used to detect changes in the apoptosis-related caspase-3/9 protein levels. We performed bioinformatics analysis and dual-luciferase assays and measured apoptotic protein levels to assess the role of the miR-221/SOX11 axis in mediating the effects of CUR-BBR. Both CUR and BBR suppressed HCC cell growth in a dose-dependent manner, with the most potent combined effect observed at a 2:1 ratio. CUR-BBR treatment significantly downregulated miR-221 expression, and miR-221 overexpression partially reversed the CUR-BBR-mediated decrease in cell survival. In addition, SOX11 was found to be a direct target of miR-221. CUR-BBR treatment upregulated SOX11 expression, and overexpression of SOX11 restored the inhibitory effects of CUR-BBR on cell growth, migration, and invasion and promoted apoptosis in the presence of miR-221. Furthermore, CUR-BBR activated pro-apoptotic proteins caspase-3/9 through the miR-221/SOX11 axis. The combined effect of CUR-BBR played an important role in inhibiting the growth of HCC cells. This combined effect was achieved by regulating the miR-221/SOX11 axis and activating the synthesis of pro-apoptotic proteins. Our findings highlight a promising combined therapeutic approach for HCC and underscore the importance of targeting the miR-221/SOX11 axis.

ASCs-EVs Inhibit Apoptosis and Promote Myocardial Function in the Infarcted Heart via miR-221

BACKGROUND

Extracellular vehicles (EVs) secreted from adipose-derived stem cells (ASCs) (ASCs-EVs) have the potential to treat myocardial infarction (MI), although the underlying mechanism remains unclear. The current study explored the ability of ASCs-EVs to inhibit apoptosis and promote myocardial function in the infarcted heart via microRNAs (miRNAs)-221.

METHODS

In hypoxia-induced H9C2 cells, a cardiac cell strain derived from the SD Rat left ventricle, we measured the cell viability and apoptosis-related protein expression after transfection with the ASCs-EVs-NC (negative control for EVs-miR-221) or ASCs-EVs-miR-221 mimics. We then verified the cardioprotective effects of miR-221-overexpressing ASCs-EVs by investigating myocardial cell apoptosis and cardiac function in a MI rat model treated with ASCs-EVs from miR-221-overexpressing ASCs by comparing control with ASC treatment.

RESULTS

The in vitro experiment results showed that the proliferation of H9C2 cells and the anti-apoptotic protein expression were significantly enhanced by the ASCs-EVs-miR-221 mimic. The in vivo experiment results found that ASCs-EVs from miR-221-overexpressing ASCs have cardioprotective effects, as demonstrated by lower serum troponin levels and left ventricular end-systolic volume, and a lower number of apoptotic myocardial cells than those in control and ASC-treated rats.

CONCLUSIONS

ASCs-EVs have therapeutic effects on MI by inhibiting cardiomyocyte apoptosis via miR-221.

Circulating miR-221/222 expression as microRNA biomarker predicting tamoxifen treatment outcome: a case-control study

The high mortality rate in breast cancer (BC) patients is generally due to metastases resistant to systemic therapy. Two causes of systemic therapy resistance in BC patients are circulating miRNAs-221 and miR-222, leading to improved BC cell proliferation, survival, and reduced cell apoptosis. This study investigated the miRNA expression changes associated with cancer cell resistance to tamoxifen therapy and is expected to be clinically meaningful before providing endocrine therapy to luminal-type BC patients who express them.

METHODS

This case-control research included individuals with the luminal subtype of BC who had received tamoxifen medication for around one year. Furthermore, the case group contained 15 individuals with local recurrence or metastases, while the control group comprised 19 patients without local recurrence or metastases. Plasma miR-221/222 quantification was performed with real-time PCR using transcript-specific primers.

RESULTS

A significant difference was found in circulating miR-221 expression between cases and controls (P=0.005) but not in miR-222 expression (P=0.070). There were no significant differences between miR-221/222 expression, progesterone receptor, Ki67 protein levels, lymphovascular invasion, and stage. However, receiver operator characteristic curve analyses showed miR-221/222 expressions predictive of tamoxifen resistance (P=0.030) with a sensitivity of 60.00 and a specificity of 83.33%.

CONCLUSION

The use of circulating miR-221/222 expression can predict relapse as well as resistance to tamoxifen treatment in BC patients, and their testing is recommended for luminal subtype BC patients who will undergo tamoxifen therapy to determine their risk of tamoxifen resistance early, increasing treatment effectiveness.

Safety and activity of the first-in-class locked nucleic acid (LNA) miR-221 selective inhibitor in refractory advanced cancer patients: a first-in-human, phase 1, open-label, dose-escalation study

BACKGROUND

We developed a 13-mer locked nucleic acid (LNA) inhibitor of miR-221 (LNA-i-miR-221) with a full phosphorothioate (PS)-modified backbone. This agent downregulated miR-221, demonstrated anti-tumor activity against human xenografts in mice, and favorable toxicokinetics in rats and monkeys. Allometric interspecies scaling allowed us to define the first-in-class LNA-i-miR-221 safe starting dose for the clinical translation.

METHODS

In this first-in-human, open-label, dose-escalation phase 1 trial, we enrolled progressive cancer patients (aged ≥ 18 years) with ECOG 0-2 into 5 cohorts. The treatment cycle was based on a 30-min IV infusion of LNA-i-miR-221 on 4 consecutive days. Three patients within the first cohort were treated with 2 cycles (8 infusions), while 14 patients were treated with a single course (4 infusions); all patients were evaluated for phase 1 primary endpoint. The study was approved by the Ethics Committee and Regulatory Authorities (EudraCT 2017-002615-33).

RESULTS

Seventeen patients received the investigational treatment, and 16 were evaluable for response. LNA-i-miR-221 was well tolerated, with no grade 3-4 toxicity, and the MTD was not reached. We recorded stable disease (SD) in 8 (50.0%) patients and partial response (PR) in 1 (6.3%) colorectal cancer case (total SD + PR: 56.3%). Pharmacokinetics indicated non-linear drug concentration increase across the dose range. Pharmacodynamics demonstrated concentration-dependent downregulation of miR-221 and upregulation of its CDKN1B/p27 and PTEN canonical targets. Five mg/kg was defined as the recommended phase II dose.

CONCLUSIONS

The excellent safety profile, the promising bio-modulator, and the anti-tumor activity offer the rationale for further clinical investigation of LNA-i-miR-221 (ClinTrials.Gov: NCT04811898).

The AR/miR-221/IGF-1 pathway mediates the pathogenesis of androgenetic alopecia

Androgenetic alopecia (AGA) affects more than half of the adult population worldwide and is primarily caused by the binding of dihydrotestosterone (DHT) to androgen receptors (AR). However, the mechanisms by which AR affects hair follicles remain unclear. In our study, we found that miR-221 significantly suppressed hair growth and the proliferation of dermal papilla cells (DPCs) and dermal sheath cells (DSCs) in AGA patients. Interestingly, miR-221 and AR were mainly co-located in the same part of the hair follicle. Mechanistic analysis revealed that AR directly promoted the transcription of miR-221, which in turn suppressed IGF-1 expression, leading to the inactivation of the MAPK pathway in DPCs and the PI3K/AKT pathway in DSCs. In AGA patients, miR-221 expression was positively correlated with AR expression and negatively correlated with IGF-1 expression. Our findings indicate that miR-221, as a direct target of AR, plays a crucial role in the pathogenesis of AGA, making it a novel biomarker and potential therapeutic target for treating AGA.

Combined Treatment of Cancer Cells Using Allyl Palladium Complexes Bearing Purine-Based NHC Ligands and Molecules Targeting MicroRNAs miR-221-3p and miR-222-3p: Synergistic Effects on Apoptosis

Combined treatments employing lower concentrations of different drugs are used and studied to develop new and more effective anticancer therapeutic approaches. The combination therapy could be of great interest in the controlling of cancer. Regarding this, our research group has recently shown that peptide nucleic acids (PNAs) that target miR-221 are very effective and functional in inducing apoptosis of many tumor cells, including glioblastoma and colon cancer cells. Moreover, in a recent paper, we described a series of new palladium allyl complexes showing a strong antiproliferative activity on different tumor cell lines. The present study was aimed to analyze and validate the biological effects of the most active compounds tested, in combination with antagomiRNA molecules targeting two miRNAs, miR-221-3p and miR-222-3p. The obtained results show that a "combination therapy", produced by combining the antagomiRNAs targeting miR-221-3p, miR-222-3p and the palladium allyl complex 4d, is very effective in inducing apoptosis, supporting the concept that the combination treatment of cancer cells with antagomiRNAs targeting a specific upregulated oncomiRNAs (in this study miR-221-3p and miR-222-3p) and metal-based compounds represents a promising therapeutic strategy to increase the efficacy of the antitumor protocol, reducing side effects at the same time.

Bone marrow mesenchymal stem cells derived exosomal miRNAs can modulate diabetic bone-fat imbalance

Background

Diabetes mellitus is a chronic metabolic disease with systemic complications. Patient with diabetes have increased risks of bone fracture. Previous studies report that diabetes could affect bone metabolism, however, the underlying mechanism is still unclear.

Methods

We isolated exosomes secreted by bone marrow mesenchymal stem cells of normal and diabetic mice and test their effects on osteogenesis and adipogenesis. Then we screened the differential microRNAs by high-throughput sequencing and explored the function of key microRNA in vitro and in vivo.

Results

We find that lower bone mass and higher marrow fat accumulation, also called bone-fat imbalance, exists in diabetic mouse model. Exosomes secreted by normal bone marrow mesenchymal stem cells (BMSCs-Exos) enhanced osteogenesis and suppressed adipogenesis, while these effects were diminished in diabetic BMSCs-Exos. miR-221, as one of the highly expressed miRNAs within diabetic BMSCs-Exos, showed abilities of suppressing osteogenesis and promoting adipogenesis both in vitro and in vivo. Elevation of miR-221 level in normal BMSCs-Exos impairs the ability of regulating osteogenesis and adipogenesis. Intriguingly, using the aptamer delivery system, delivery normal BMSCs-Exos specifically to BMSCs increased bone mass, reduced marrow fat accumulation, and promoted bone regeneration in diabetic mice.

Conclusion

We demonstrate that BMSCs derived exosomal miR-221 is a key regulator of diabetic osteoporosis, which may represent a potential therapeutic target for diabetes-related skeletal disorders.

Triptolide improves chondrocyte proliferation and secretion via down-regulation of miR-221 in synovial cell exosomes

BACKGROUND

Rheumatoid arthritis (RA), the most common type of inflammatory arthritis, can cause bone damage and disability. Triptolide, a prominent treatment for RA, has satisfactory anti-inflammatory effects. However, the mechanism of action of triptolide in RA remains unknown.

PURPOSE

This study aimed to explore the molecular mechanisms underlying triptolide-mediated improvements in RA and identify the miRNA pathway responsible for these effects.

METHODS

We identified various dysregulated miRNAs associated with RA by mining previously described microarray data and verified and screened these candidates using RT-qPCR. Hematoxylin-eosin staining was then applied to identify pathological changes in the affected joints, and cell counting kit-8 analysis and flow cytometry were employed to examine cell proliferation and apoptosis, respectively. Extracted exosomes were verified using transmission electron microscopy.

RESULTS

Our results revealed that the legs of rats with collagen-induced arthritis presented with obvious swelling and bone damage, a high degree of inflammatory cell infiltration into the synovium, and structural changes to the cartilage. Data mining identified 39 dysregulated miRNAs in these tissues, and RT-qPCR further refined these observations to highlight miR-221 as a potential RA biomarker. Subsequent evaluations revealed that fibroblast-like synovial (FLS) cells secrete Exs carrying dysregulated miR-221 in vitro. These Exs mediate miR-221 levels, inflammation, and TLR4/MyD88 signaling via their fusion with chondrocytes, leading to changes in chondrocyte growth and metabolic factor levels. Additionally, the addition of triptolide impaired miR-221 expression, cell proliferation, inflammatory factors, and the protein levels of TLR4/MyD88 in RA-FLS and promoted the apoptosis of FLS. The therapeutic effect of triptolide on miR-221 Exs was reversed by miR-221 inhibitor in both normal and RA FLS.

CONCLUSION

Our research shows that effective treatment with triptolide is mediated by its regulation of growth and secretory functions of chondrocytes via the inhibition of miR-221 secretion by FLS, providing a new target and natural medicinal candidate for future RA treatments.

Effects of metformin on changes of miR-19a and miR-221 expression associated with myocardial infarction in patients with type 2 diabetes

BACKGROUND

The presence of hyperglycemia is a risk factor for cardiovascular diseases, as it increases the risk of myocardial infarction (MI). Metformin is considered an effective anti-hyperglycemic drug for patients with type 2 diabetes. Prediction of microRNAs is valuable in determining the risk of MI.

AIM

This study aimed to measure the expression of two microRNAs, which are involved in the risk of MI and vascular stenosis among metformin users and non-users with MI.

METHODS

In this study, we analyzed the expression of two microRNAs, collected from the blood samples of 180 subjects with MI, using the quantitative polymerase chain reaction (qPCR) assay. The subjects were categorized into three groups: non-diabetic patients with MI (MIND), diabetic patients with MI not using metformin (MIDMet-), and diabetic patients with MI using metformin (MIDMet+). To assess the sensitivity and specificity of miR-19a and miR-221 expression as potential biomarkers for MI, the receiver operating characteristic curve (ROC) analysis was conducted for both diabetic groups.

RESULTS

The diabetic MIDMet + group exhibited a significant decrease in the expression levels of miR-221 (7.2 folds) and miR-19a (5.3 folds) as compared to the MIDMet- and MIND groups (p < 0.05). The ROC analysis revealed that the areas under the ROC curve (AUC) for circulating miR-19a and miR-221 were 0.931 and 0.965 in patients with type 2 diabetes, respectively (p < 0.001).

CONCLUSION

Based on the present findings, metformin therapy can influence cardiovascular disorders and their outcomes through down-regulation of microRNAs. Also, exploration of microRNAs and the effects of metformin on their reduction can provide a potential therapeutic strategy for patients with type 2 diabetes by reducing the MI risk.

Oral Cancer Cells Release Vesicles that Cause Pain

Oral cancer pain is attributed to the release from cancers of mediators that sensitize and activate sensory neurons. Intraplantar injection of conditioned media (CM) from human tongue cancer cell line HSC-3 or OSC-20 evokes nociceptive behavior. By contrast, CM from noncancer cell lines, DOK, and HaCaT are non-nociceptive. Pain mediators are carried by extracellular vesicles (EVs) released from cancer cells. Depletion of EVs from cancer cell line CM reverses mechanical allodynia and thermal hyperalgesia. CM from non-nociceptive cell lines become nociceptive when reconstituted with HSC-3 EVs. Two miRNAs (hsa-miR-21-5p and hsa-miR-221-3p) are identified that are present in increased abundance in EVs from HSC-3 and OSC-20 CM compared to HaCaT CM. The miRNA target genes suggest potential involvement in oral cancer pain of the toll like receptor 7 (TLR7) and 8 (TLR8) pathways, as well as signaling through interleukin 6 cytokine family signal transducer receptor (gp130, encoded by IL6ST) and colony stimulating factor receptor (G-CSFR, encoded by CSF3R), Janus kinase and signal transducer and activator of transcription 3 (JAK/STAT3). These studies confirm the recent discovery of the role of cancer EVs in pain and add to the repertoire of algesic and analgesic cancer pain mediators and pathways that contribute to oral cancer pain.

Expression of miR-221 and miR-18a in patients with hepatocellular carcinoma and its clinical significance

Purpose

Recently, microRNA (miRNA) has been evaluated to provide a new diagnostic and therapeutic modality hepatocellular carcinoma (HCC) and other tumors. They are small non-coding RNA molecules that function as transcriptional and post-transcriptional regulators of gene expression by silencing target genes. The aim of this study was to evaluate the clinical significance of microRNA-18a, 221 (miR-18a, miR-221) expression in HCC formalin-fixed paraffin-embedded (FFPE) tissue.

Methods

miR-18a and miR-221 expressions were assessed by reverse transcription and real-time quantitative reverse transcription polymerase chain reaction in 50 pairs of FFPE HCC and the adjacent noncancerous liver tissues. And we evaluated the expression level in HCC tissues as compared with their adjacent noncancerous counterparts. And the relationship between miR-18a, miR-221 level and clinicopathological data and survival rates were analyzed.

Results

miR-221 and miR-18a were overexpressed in HCC tissue as compared with their adjacent noncancerous liver tissue (P<0.001). miR-221 expression was found to be correlated with larger tumor size (P=0.048). miR-18a expression was correlated with modified Union for International Cancer Control stage (P=0.05). The overall survival (P=0.02) of HCC patients with high miR-221 expression was significantly poorer compared to those patients with low expression. Multivariate analyses demonstrated that miR-221 may be a poor prognostic factor of HCC patients.

Conclusion

High expression of miR-221 in FFPE tissues could provide significance for prognosis of HCC patients. Although, miR-18a expression was significantly upregulated in HCC tissues, they are not correlated with prognosis. Further large prospective studies are needed to determine their clinical significance.

Role of let7-g and miR-221 level as potential predictors for overall survival of hepatocellular carcinoma patients

BACKGROUND AND STUDY AIMS

Hepatocellular carcinoma (HCC) is one of the most common cancer types worldwide. A hallmark of epithelial-mesenchymal transition is the loss of epithelial E-cadherin, which is considered an epithelial differentiation marker. MicroRNAs serve vital roles in various biological processes in the cell via post-transcriptional gene regulation. Therefore, the present study aimed to investigate the involvement of certain miRNAs in the progression of HCC.

PATIENTS AND METHODS

A reverse transcription-quantitative PCR assay was conducted to detect the expression levels of 20 EMT-related miRNAs in 36 fresh tissue biopsies from patients with primary HCC compared with healthy controls. Gene expression levels, as well as immunohistochemistry assays, were performed for E-cadherin, ZEB1 and ZEB2 proteins. The correlation between their expression levels and different clinicopathological factors was also assessed.

RESULTS

A significant decrease of E-Cadherin and an increase in ZEB1 expression levels were identified in HCC groups compared with controls, while no significant changes for ZEB2 were found. The absence of E-cadherin membranous protein was observed in ∼48% of the cases examined. Moreover, ZEB1 protein was absent in 46% of E-cadherin positive cases. Upregulation of miR-182, miR-221 and miR-222 expression levels, and downregulation of let-7g, miR-9, miR-16, miR29c, miR122, miR-145, miR-148a, miR-193b, miR-194 and miR-215 expression levels were identified. A positive correlation between let7-g with E-Cadherin expression was reported. No significant association was identified between each of E-cadherin, ZEB1, ZEB2 or miRNAs examined with different clinicopathological features of the patients. Furthermore, the low expression of let7-g and high expression of miR-221 were associated with poorer survival.

CONCLUSION

Collectively, the present data suggested that let7-g functions as a tumor suppressor in the development of HCC via regulating E-Cadherin. Furthermore, both let7-g and miR-221 may be potential biomarkers for the outcomes of HCC patients.

miR-221 promotes keratinocyte proliferation and migration by targeting SOCS7 and is regulated by YB-1

Proliferation and migration of keratinocytes are vital processes for the successful epithelization specifically after wounding. MiR‐221 has been identified to play a potential role in promoting wound regeneration by inducing blood vessel formation. However, little is known about the role of miR‐221 in the keratinocyte proliferation and migration during wound healing. An in vivo mice wound‐healing model was generated; the expression levels of miR‐221 were assessed by qRT‐PCR and fluorescence in situ hybridization. Initially, we found that miR‐221 was upregulated in the proliferative phase of wound healing. Further, in an in vivo wound‐healing mice model, targeted delivery of miR‐221 mimics accelerated wound healing. Contrastingly, inhibition of miR‐221 delayed healing. Additionally, we observed that overexpression of miR‐221 promoted cell proliferation and migration, while inhibition of miR‐221 had the opposite effects. Moreover, we identified SOCS7 as a direct target of miR‐221 in keratinocytes and overexpression of SOCS7 reversed the effects of miR‐221 in HaCaT keratinocytes. Finally, we identified that YB‐1 regulates the expression of miR‐221 in HaCaT keratinocytes. Overall, our experiments suggest that miR‐221 is regulated by YB‐1 in HaCaT keratinocytes and acts on SOCS7, thereby playing an important role in HaCaT keratinocyte proliferation and migration during wound healing.

Estradiol overcomes adiponectin-resistance in diabetic mice by regulating skeletal muscle adiponectin receptor 1 expression

Adiponectin and insulin resistance creates a vicious cycle that exacerbates type 2 diabetes. Earlier, we observed that female leptin receptor-deficient BLKS mice (BKS-db/db) were more sensitive to an adiponectin mimetic GTDF than males, which led us to explore if E2 plays a crucial role in modulation of adiponectin-sensitivity. Male but not female BKS-db/db mice were resistant to metabolic effects of globular adiponectin treatment. Male BKS-db/db displayed reduced skeletal muscle AdipoR1 protein expression, which was consequent to elevated polypyrimidine tract binding protein 1 (PTB) and miR-221. E2 treatment in male BKS-db/db, and ovariectomized BALB/c mice rescued AdipoR1 protein expression via downregulation of PTB and miR-221, and also directly increased AdipoR1 mRNA by its classical nuclear receptors. Estrogen receptor regulation via dietary or pharmacological interventions may improve adiponectin resistance and consequently ameliorate insulin resistance in type 2 diabetes.

Long non-coding RNA HOTAIRincreased mechanical stimulation-induced apoptosis by regulating microRNA-221/BBC3 axis in C28/I2 cells

Abnormal mechanical stimulation contributes to articular cartilage degeneration and osteoarthritis (OA) development. Many long noncoding RNAs (lncRNAs) are involved in mechanical force-induced cartilage degeneration. LncRNA HOTAIR (HOTAIR) has been demonstrated to increase osteoarthritis progression. However, the roles of HOTAIR in mechanical stimulation-treated chondrocytes are still unclear. In this study, we found that mechanical stimulation significantly induced apoptosis in C28/I2 cells. In addition, the expression of HOTAIR was up regulated and the expression of miR-221 was down regulated. Knockdown of HOTAIR effectively ameliorated cell apoptosis induced by mechanical stimulation. HOTAIR could interact with miR-221, which targeted to degrade BBC3. Overexpression of BBC3 could reverse the decreased apoptotic rates induced by HOTAIR knockdown. Collectively, HOTAIR promoted mechanical stimulation-induced apoptosis by regulating the miR-221/BBC3 axis in C28/I2 cells.

MicroRNA-221 inhibits the transition of endothelial progenitor cells to mesenchymal cells via the PTEN/FoxO3a signaling pathway

BACKGROUND

Coronary heart disease is one of the most common cardiovascular diseases worldwide and is often associated with vascular endothelial injury. Endothelial-mesenchymal transition (EndMT) is an important process in vascular endothelial injury.

OBJECTIVES

This study investigated the function of miR-221 in the EndMT process of endothelial progenitor cells (EPCs).

MATERIAL AND METHODS

Transforming growth factor beta (TGF-β1) was used to induce EndMT in EPCs, and SM22α expression was detected using immunocytochemistry. Western blot was used to detect alpha smooth muscle actin (αSMA) expression, and miR-221 function was evaluated using inhibitors or mimics of the miR-221 sequences that were transfected into EPCs. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression of miR-221 and western blot was used to detect the expression of αSMA, myocardin, phosphatase and tensin homolog (PTEN), p-FoxO3a, and FoxO3a in EPCs. Finally, the expression of the miR-221 target genes was determined using RT-PCR.

RESULTS

The expression of SM22α and αSMA increased in EPCs treated with TGF-β1, while the expression of miR-221 was decreased in EPCs on the 5th day, when compared with the control. The expression of SM22α increased after inhibiting miR-221 in EPCs treated with TGF-β1 and this was reversed by the overexpression of miR-221. The expression of αSMA and myocardin was significantly increased after inhibiting miR-221 in EPCs treated with TGF-β1 and decreased in EPCs overexpressing miR-221. Conversely, PTEN was increased in TGF-β1-treated EPCs and decreased following the overexpression of miR-221. The decrease in phosphorylated-FoxO3a expression in EPCs was accompanied by an increase in αSMA expression, which was reversed in the presence of miR-221 mimics. This effect was nearly abolished following the addition of PTEN cDNA.

CONCLUSIONS

The overexpression of miR-221 inhibits EndMT in EPCs, possibly by interacting with PTEN to regulate FoxO3a signaling, to facilitate the repair of the endothelium by EPCs.

Circulating miR-221/222 reduces CD4+ T cells by inhibiting CD4 expression in colorectal cancer

Many patients with cancers have low levels of CD4+ in their peripheral blood. However, the molecular mechanism is still unclear. Here, we found that the blood levels of miR-221 and miR-222 were dramatically increased in patients with colorectal cancer (CRC), and both circulating miR-211 and miR-222 served as sensitive diagnostic markers with an area under the curve of 0.8790 and 0.9148, respectively. Transfection of either miR-221 or miR-222 resulted in the reduction of the surface CD4 antigen level but not the surface CD8 antigen level. The luciferase reporter assay showed that miR-221/222 directly regulated CD4 expression in human primary T cells. These data showed that miR-221/222 levels were upregulated in the blood of patients with CRC and that the expression of CD4 in human primary T cells was inhibited by miR-221/222. These findings provide a novel strategy for modulating the number of CD4+ T cells in the blood and further adjusting the microenvironment suitable for immunotherapy.

Circulating Exosomal miR-221 from Maternal Obesity Inhibits Angiogenesis via Targeting Angptl2

Maternal obesity disrupts both placental angiogenesis and fetus development. However, the links between adipocytes and endothelial cells in maternal obesity are not fully understood. The aim of this study was to characterize exosome-enriched miRNA from obese sow’s adipose tissue and evaluate the effect on angiogenesis of endothelial cells. Plasma exosomes were isolated and analyzed by nanoparticle tracking analysis (NTA), electron morphological analysis, and protein marker expression. The number of exosomes was increased as the gestation of the sows progressed. In addition, we found that exosomes derived from obese sows inhibited endothelial cell migration and angiogenesis. miRNA detection showed that miR-221, one of the miRNAs, was significantly enriched in exosomes from obese sows. Further study demonstrated that exosomal miR-221 inhibited the proliferation and angiogenesis of endothelial cells through repressing the expression of Angptl2 by targeting its 3′ untranslated region. In summary, miR-221 was a key component of the adipocyte-secreted exosomal vesicles that mediate angiogenesis. Our study may be a novel mechanism showing the secretion of “harmful” exosomes from obesity adipose tissues causes placental dysplasia during gestation.

LncRNA SCIRT absorbs miR-221 to advance the expression of lncRNA GAS5 in oral squamous cell carcinoma to inhibit cancer cell apoptosis

BACKGROUND

Although SCIRT has been reported to suppress breast cancer, its role in other cancers, such as oral squamous cell carcinoma (OSCC), is hardly known. We predicted that SCIRT might interact with miR-221 to target lncRNA GAS5 and analyzed the interaction between SCIRT and miR-221 in OSCC.

METHODS

SCIRT and miR-221 expression levels were quantified using RT-qPCR. SCIRT subcellular localization was analyzed by subcellular fractionation assay. RNA pull-down assay was applied to study the interaction between SCIRT and miR-221. The role of SCIRT and miR-221 in regulating GAS5 expression was analyzed by overexpression assay and RT-qPCR. Cell apoptosis was analyzed by flow cytometry.

RESULTS

SCIRT and GAS5 were downregulated, while miR-221 was overexpressed in OSCC. SCIRT was detected in both nucleus and cytoplasm and directly interacted with miR-221, while SCIRT overexpression failed to affect miR-221 expression. In addition, GAS5 expression was increased by SCIRT and decreased by miR-221. Moreover, SCIRT suppressed the role of miR-221 in suppressing GAS5 expression and OSCC cell apoptosis.

CONCLUSION

SCIRT sponges miR-221 to upregulate lncRNA GAS5 in OSCC and inhibit cancer cell apoptosis.

MicroRNA-Based Risk Score for Predicting Tumor Progression Following Radioactive Iodine Ablation in Well-Differentiated Thyroid Cancer Patients: A Propensity-Score Matched Analysis

Simple Summary

The three-tiered American Thyroid Association (ATA) risk stratification helps clinicians tailor decisions regarding follow-up modalities and the need for postoperative radioactive iodine (RAI) ablation and radiotherapy. However, a significant number of well-differentiated thyroid cancers (DTC) progress after treatment. Current follow-up modalities have also been proposed to detect disease relapse and recurrence but have failed to be sufficiently sensitive or specific to detect, monitor, or determine progression. Therefore, we assessed the predictive accuracy of the microRNA-based risk score in DTC with and without postoperative RAI. We confirm the prognostic role of triad biomarkers (miR-2f04, miR-221, and miR-222) with higher sensitivity and specificity for predicting disease progression than the ATA risk score. Compared to indolent tumors, a higher risk score was found in progressive samples and was associated with shorter survival. Consequently, our prognostic microRNA signature and nomogram provide a clinically practical and reliable ancillary measure to determine the prognosis of DTC patients.

Abstract

To identify molecular markers that can accurately predict aggressive tumor behavior at the time of surgery, a propensity-matching score analysis of archived specimens yielded two similar datasets of DTC patients (with and without RAI). Bioinformatically selected microRNAs were quantified by qRT-PCR. The risk score was generated using Cox regression and assessed using ROC, C-statistic, and Brier-score. A predictive Bayesian nomogram was established. External validation was performed, and causal network analysis was generated. Within the eight-year follow-up period, progression was reported in 51.5% of cases; of these, 48.6% had the T1a/b stage. Analysis showed upregulation of miR-221-3p and miR-222-3p and downregulation of miR-204-5p in 68 paired cancer tissues (p < 0.001). These three miRNAs were not differentially expressed in RAI and non-RAI groups. The ATA risk score showed poor discriminative ability (AUC = 0.518, p = 0.80). In contrast, the microRNA-based risk score showed high accuracy in predicting tumor progression in the whole cohorts (median = 1.87 vs. 0.39, AUC = 0.944) and RAI group (2.23 vs. 0.37, AUC = 0.979) at the cutoff >0.86 (92.6% accuracy, 88.6% sensitivity, 97% specificity) in the whole cohorts (C-statistics = 0.943/Brier = 0.083) and RAI subgroup (C-statistic = 0.978/Brier = 0.049). The high-score group had a three-fold increased progression risk (hazard ratio = 2.71, 95%CI = 1.86–3.96, p < 0.001) and shorter survival times (17.3 vs. 70.79 months, p < 0.001). Our prognostic microRNA signature and nomogram showed excellent predictive accuracy for progression-free survival in DTC.

The prognostic significance of microRNA-221 in hepatocellular carcinoma: An updated meta-analysis

BACKGROUND

Recently, microRNA-221 has been found to be abnormally expressed in hepatocellular carcinoma; however, its clinical value has not been summarised. This meta-analysis aimed to assess the prognostic significance of miR-221 in hepatocellular carcinoma.

MATERIAL AND METHODS

PubMed, Science Direct, Web of Science, Scopus, Ovid MEDLINE, EMbase, Google Scholar, the Cochrane Library, CNKI, CBM, VIP and Wanfang databases were searched for eligible articles. The endpoints included overall survival, progression-free survival, recurrence-free survival, metastasis-free survival, disease-free survival. Hazard ratios with 95% confidence intervals were used to explore the relationship between miR-221 expression and clinical survival results of liver cancer patients. Subgroup analysis and sensitivity analysis were performed. Begg's test and Egger's test were conducted to evaluate publication bias.

RESULTS

A total of nine studies including 607 patients were recruited for this meta-analysis. The pooled hazard ratios displayed that high miR-221 expression was remarkably associated with poorer overall survival (hazard ratio = 1.91, 95% confidence interval: 1.53-2.38, p ＜ 0.01) and unfavourable progression-free survival/recurrence-free survival/metastasis-free survival/disease-free survival (hazard ratio = 2.02, 95% confidence interval: 1.58-2.57, p ＜ 0.01). The results of Begg's test and Egger's test did not exhibit obvious publication bias.

CONCLUSIONS

High expression of miR-221 can predict poor outcome of hepatocellular carcinoma. miR-221 can be used as a promising prognostic biomarker of hepatocellular carcinoma.

Exosomes Derived from Hydroquinone-transformed Human Bronchial Epithelial Cells Inhibited Recipient Cell Apoptosis by transferring miR-221

OBJECTIVE

Although benzene is a confirmed environmental carcinogen, the mechanism of its carcinogenicity remains largely unclear. The suggested oncogene, miR-221, is elevated and plays important roles in various tumors, but its role in benzene-induced carcinogenesis remains unknown.

METHODS

In the present study, we constructed hydroquinone (HQ, a representative metabolite of benzene with biological activity)-transformed malignant cell line (16HBE-t) and analyzed the level of miR-221 in it with qRT-PCR. Exosomes from 16HBE-t cells incubated with or without an miR-221 inhibitor were isolated by ultracentrifugation, characterized by transmission electron microscopy and laser scanning confocal microscope, and then transfected into 16HBE cells. The effects of exosomal miR-221 on apoptosis induced by HQ in recipient cells were determined using flow cytometry.

RESULTS

The amount of miR-221 in 16HBE-t was significantly increased compared with controls. When recipient cells ingested exosomes derived from 16HBE-t, miR-221 was increased, and apoptosis induced by HQ was inhibited. Blocking miR-221 in 16HBE-t using an inhibitor did not significantly alter miR-221 or apoptosis in recipient cells.

CONCLUSION

Exosomal miR-221 secreted by 16HBE-t inhibits apoptosis induced by HQ in normal recipient cells.

Exosome-delivered miR-221/222 exacerbates tumor liver metastasis by targeting SPINT1 in colorectal cancer

MicroRNAs (miRNAs) are involved in the progression of many cancers through largely unelucidated mechanisms. The results of our present study identified a gene cluster, miR-221/222, that is constitutively upregulated in serum exosome samples of patients with colorectal carcinoma (CRC) with liver metastasis (LM); this upregulation predicts a poor overall survival rate. Using an in vitro cell coculture model, we demonstrated that CRC exosomes harboring miR-221/222 activate liver hepatocyte growth factor (HGF) by suppressing SPINT1 expression. Importantly, miR-221/222 plays a key role in forming a favorable premetastatic niche (PMN) that leads to the aggressive nature of CRC, which was further shown through in vivo studies. Overall, our results show that exosomal miR-221/222 promotes CRC progression and may serve as a novel prognostic marker and therapeutic target for CRC with LM.

Oral squamous cell carcinoma (OSCC)-derived exosomal MiR-221 targets and regulates phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) to promote human umbilical vein endothelial cells migration and tube formation

Oral squamous cell carcinoma (OSCC) is the most common tumor of the oral cavity. Studies have shown that exosomal miRNAs from cancer cells play an important role in mediating the cellular environment. The objective was to investigate the effect of OSCC-derived exosomes microRNA-221 (miR-221) in OSCC. We used quantitative real-time PCR (qRT-PCR) and western blotting to determine PIK3R1 and miR-221 expressions in OSCC tissue or peripheral blood serum. Exosomes of OSCC cell line CAL27 were extracted and characterized. Exosomal miR-221 expression was detected by qRT-PCR. Dual-luciferase was performed to validate the targeted regulatory relationship of miR-221 on PIK3R1. Transwell and tube formation assay were applied to detect the effect of OSCC-derived exosomal miR-221 on HUVEC migration and angiogenesis. qRT-PCR confirmed that PIK3R1 expression was downregulated in OSCC tissue and cell line, while miR-221 expression was upregulated. miR-221 expression in OSCC cell line-derived exosome elevated. miR-221 could target and negatively regulate PIK3R1 expression. In addition, OSCC-derived miR-221 could promote HUVEC migration and angiogenesis. In conclusion, OSCC-derived exosomal miR-221 could target and negatively regulate PIK3R1 expression, as well as promote vascular endothelial cell migration and angiogenesis.

Investigation of the role of miR-221 in diabetic peripheral neuropathy and related molecular mechanisms

BACKGROUND

Diabetic peripheral neuropathy (DPN) is one of the most common complications of diabetes, but the molecular mechanisms of DPN are still unclear.

OBJECTIVES

To investigate the role of miR-221 in DPN and the related molecular mechanisms.

MATERIAL AND METHODS

Streptozotocin (STZ) was used to establish an in vivo DPN model. An in vitro DPN model was established using high glucose-induced SH-SY5Y cells. The pain condition of rats was measured by evaluating the 50% paw withdrawal threshold (PWT) and paw withdrawal latency (PWL). Serum exosomes were extracted and identified. Expression of miR-221 in serum exosomes and serum SOCS3 expression were determined using reverse-transcription quantitative polymerase chain reaction (RT-qPCR). Western blotting was used to measure the protein levels of SOCS3, bradykinin (BK) and prostaglandin E2 (PEG2). The dual luciferase reporter assay was performed to confirm SOCS3 3'-UTR as a target of miR-221. The serum or cell supernatant levels of PEG2, BK, interleukin (IL)-6, IL-1β, and tumor necrosis factor alpha (TNF-α) were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Induction of the lenti-miR-221 inhibitor significantly decreased the expression of miR-221 in DPN rats. Both 50% PWT and PWL values were markedly decreased in DPN rats. When miR-221 was inhibited, the 50% PWT and PWL values were both significantly increased. Knockdown of miR-221 significantly increased the expression of SOCS3 and decreased the expression of NF-κB. Furthermore, knockdown of miR-221 remarkably decreased the expression of PEG2, BK, IL-6, IL-1β, and TNF-α in both STZ-treated DPN rats and high glucose-induced SH-SY5Y cells, which was reversed by inhibition of SOCS3. The dual luciferase reporter assay showed that miR-221 directly targeted and negatively regulated SOCS3.

CONCLUSIONS

Inhibition of miR-221 can reduce pain and decrease expression of inflammatory factors through targeting SOCS3 in DPN.

Isolation and Quantification of miRNA from the Biomolecular Corona on Mesoporous Silica Nanoparticles

To understand the factors that control the formation of the biomolecular corona, a systematic study of the adsorption of several miRNAs shown to be important in prostate cancer on amine-functionalized mesoporous silica nanoparticles (MSN-NH₂) has been performed. Process parameters including miRNA type, nanoparticle concentration, incubation temperature and incubation time were investigated, as well as the potential competition for adsorption between different miRNA molecules. The influence of proteins and particle PEGylation on miRNA adsorption were also explored. We found that low particle concentrations and physiological temperature both led to increased miRNA adsorption. Adsorption of miRNA was also higher when proteins were present in the same solution; reducing or preventing protein adsorption by PEGylating the MSNs hindered adsorption. Finally, the amount of miRNA adsorbed from human serum by MSN-NH₂ was compared to a commercial miRNA purification kit (TaqMan^®, Life Technologies, Carlsbad, CA, USA). MSN-NH₂ adsorbed six times as much miRNA as the commercial kit, demonstrating higher sensitivity to subtle up- and downregulation of circulating miRNA in the blood of patients.

The changes in miR-221 and miR-222 before and after interventional therapy of coronary heart disease and analysis of their correlation with inflammatory factors and prognosis

OBJECTIVE

To explore the changes in miR-221 and miR-222 before and after interventional therapy of coronary heart disease and their relationship with inflammatory factors and prognosis.

METHODS

A total of 122 subjects with coronary heart disease who underwent interventional therapy in our hospital from January 2017 to January 2019 were chosen as the observation group, and 122 healthy people during the same period were chosen as the control group. We retrospectively analyzed the levels of serum miR-221, miR-222, C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6). Pearson correlation analysis was used to reveal the relationship between serum levels of miR-221, miR-222 and CRP, TNF-α and IL-6, N-terminal B-type brain natriuretic peptide precursor (NT-proBNP) and left ventricular ejection fraction (LVEF%) in the observation group. The levels of serum miR-221, miR-222, TNF-α, CRP and IL-6 before and after treatment were compared in the observation group. After a follow-up of 6 months, the observation group was divided into a poor-prognosis group (26 cases) and a good-prognosis group (96 cases) according to whether there was an adverse cardiovascular event or not. The levels of serum miR-221 and miR-222 before and after intervention treatment were compared between the two groups. And the clinical values of miR-221 and miR-222 levels before and after intervention treatment in the observation group were analyzed by the ROC curve.

RESULTS

The levels of serum miR-221, miR-222, CRP, TNF-α, and IL-6 in the observation group were markedly higher than those of the control group. And levels of serum miR-221, miR-222 were negatively correlated with LVEF% while positively correlated with CRP, TNF-α, IL-6 and NT-proBNP (P<0.05). After treatment, the levels of miR-221, miR-222, CRP, TNF-α, and IL-6 in the observation group were significantly reduced (all P<0.05). Compared with the good prognosis group, the levels of miR-221 and miR-222 before and after treatment were markedly higher in the poor prognosis group (all P<0.05). Both before and after treatment, the levels of miR-221 and miR-222 have certain clinical value in evaluating the prognosis (all AUC>0.800).

CONCLUSION

The levels of miR-221 and miR-222 in patients with coronary heart disease significantly increased and they were closely correlated with the inflammatory factors, NT-proBNP and LVEF%. The levels of miR-221 and miR-222 before and after treatment have certain clinical value in evaluating the prognosis of patients.

Atorvastatin improves the proliferation and migration of endothelial progenitor cells via the miR-221/VEGFA axis

The present study was aimed at investigating the detailed functions of atorvastatin, a lipid-lowering agent, in the pathogenesis of coronary slow flow (CSF), a clinical disease characterized by delayed angiographic coronary opacity without obstructive coronary disease. In the present study, we successfully identified isolated endothelial progenitor cells (EPCs) from the peripheral blood of patients with CSF. Their vascular endothelial growth factor-A (VEGFA) protein levels were determined using immunoblotting analyses. We determined cell viability using MTT assays, cell migration capacity using Transwell assays, and the angiogenic capacity using a tube formation assay. The target association between miR-221 and VEGFA was validated with a luciferase reporter assay. Atorvastatin treatment increased EPC VEGFA protein levels, proliferation, migration, and angiogenesis. miR-221 expression was down-regulated after atorvastatin treatment; miR-221 overexpression exerted an opposing effect to atorvastatin treatment on VEGFA protein, EPC proliferation, migration, and angiogenesis. The protective effects of atorvastatin treatment on VEGFA protein and EPCs could be significantly suppressed by miR-221 overexpression. miR-221 directly bound the VEGFA 3'UTR to inhibit its expression. In conclusion, atorvastatin improves the cell proliferation, migration, and angiogenesis of EPCs via the miR-221/VEGFA axis. Thus, atorvastatin could be a potent agent against CSF, pending further in vivo and clinical investigations.

miR-155 Contributes to the Immunoregulatory Function of Human Mesenchymal Stem Cells

Objectives

Mesenchymal stem/stromal cells (MSCs) are widely investigated in regenerative medicine thanks to their immunomodulatory properties. They exert their anti-inflammatory function thanks to the secretion of a number of mediators, including proteins and miRNAs, which can be released in the extracellular environment or in the cargo of extracellular vesicles (EVs). However, the role of miRNAs in the suppressive function of MSCs is controversial. The aim of the study was to identify miRNAs that contribute to the immunomodulatory function of human bone marrow-derived MSCs (BM-MSCs).

Methods

Human BM-MSCs were primed by coculture with activated peripheral blood mononuclear cells (aPBMCs). High throughput miRNA transcriptomic analysis was performed using Human MicroRNA TaqMan® Array Cards. The immunosuppressive function of miRNAs was investigated in mixed lymphocyte reactions and the delayed type hypersensitivity (DTH) murine model.

Results

Upon priming, 21 out of 377 tested miRNAs were significantly modulated in primed MSCs. We validated the up-regulation of miR-29a, miR-146a, miR-155 and the down-regulation of miR-149, miR-221 and miR-361 in additional samples of primed MSCs. We showed that miR-155 significantly reduced the proliferation of aPBMCs in vitro and inflammation in vivo, using the DTH model. Analysis of miRNA-mRNA interactions revealed miR-221 as a potential target gene that is down-regulated by miR-155 both in primed MSCs and in aPBMCs.

Conclusion

Here, we present evidence that miR-155 participates to the immunosuppressive function of human BM-MSCs and down-regulates the expression of miR-221 as a possible inflammatory mediator.

Prognostic Value of microRNA-221/2 and 17-92 Families in Primary Glioblastoma Patients Treated with Postoperative Radiotherapy

MicroRNAs (miRs) are non-coding master regulators of transcriptome that could act as tumor suppressors (TSs) or oncogenes (oncomiRs). We aimed to systematically investigate the relevance of miRs as prognostic biomarkers in primary glioblastoma multiforme (GBM) treated with postoperative radio(chemo)therapy (PORT). For hypothesis generation, tumor miR expression by Agilent 8x15K human microRNA microarrays and survival data from 482 GBM patients of The Cancer Genome Atlas (TCGA cohort) were analyzed using Cox-PH models. Expression of candidate miRs with prognostic relevance (miR-221/222; miR-17-5p, miR-18a, miR-19b) was validated by qRT-PCR using Taqman technology on an independent validation cohort of GBM patients (n = 109) treated at Heidelberg University Hospital (HD cohort). In TCGA, 50 miRs showed significant association with survival. Among the top ranked prognostic miRs were members of the two miR families miR-221/222 and miR-17-92. Loss of miR-221/222 was correlated with improved prognosis in both cohorts (TCGA, HD) and was an independent prognostic marker in a multivariate analysis considering demographic characteristics (age, sex, Karnofsky performance index (KPI)), molecular markers (O-6-methylguanine-DNA methyltransferase (MGMT) methylation, IDH mutation status) and PORT as co-variables. The prognostic value of miR-17-92 family members was ambiguous and in part contradictory by direct comparison of the two cohorts, thus warranting further validation in larger prospective trials.

Papillary Thyroid Carcinoma Tissue miR-146b, -21, -221, -222, -181b Expression in Relation with Clinicopathological Features

We analyzed miR-146b, miR-21, miR-221, miR-21, and miR-181b in formalin fixed paraffin-embedded papillary thyroid carcinoma (PTC) tissue samples of 312 individuals and evaluated their expression relationship with clinicopathological parameters. A higher expression of miR-21 was related to unifocal lesions (p < 0.011) and autoimmune thyroiditis (0.007). miR-221, miR-222 expression was higher in the PTC tissue samples with extrathyroidal extension (p = 0.049, 0.003, respectively). In a group of PTC patients with pT1a and pT1b sized tumors, the expression of miR-146b, miR-21, miR-221, and miR-222 in PTC tissue samples was lower than in patients with pT2, pT3, and pT4 (p = 0.032; 0.0044; 0.003; 0.001; 0.001, respectively). Patients with lymph node metastases had higher expression of miR-21, -221, -222, and -181b (p < 0.05). A high expression of miR-146b, miR-21, miR-221 panel was associated with decreased overall survival (OS) (Log rank p = 0.019). Univariate analysis revealed that presence of metastatic lymph nodes and high expression of miR-146b, miR-21, and miR-221 panels were associated with increased hazard of shorter OS. After multivariate analysis, only sex (male) and age (≥55 years) emerged as independent prognostic factors associated with shorter OS (HR 0.28 (95% CI 0.09–0.86) and HR 0.05 (95% CI 0.01–0.22), respectively). In conclusion, 5 analyzed miRs expression have significant relations to clinicopathologic parameters so further investigations of these molecules are expedient while searching for prognostic PTC biomarkers.

MicroRNA-221 and -222 modulate intestinal inflammatory Th17 cell response as negative feedback regulators downstream of interleukin-23

MicroRNAs are important regulators of immune responses. Here, we show miR-221 and miR-222 modulate the intestinal Th17 cell response. Expression of miR-221 and miR-222 was induced by proinflammatory cytokines and repressed by the cytokine TGF-β. Molecular targets of miR-221 and miR-222 included Maf and Il23r, and loss of miR-221 and miR-222 expression shifted the transcriptomic spectrum of intestinal Th17 cells to a proinflammatory signature. Although the loss of miR-221 and miR-222 was tolerated for maintaining intestinal Th17 cell homeostasis in healthy mice, Th17 cells lacking miR-221 and miR-222 expanded more efficiently in response to IL-23. Both global and T cell-specific deletion of miR-221 and miR-222 rendered mice prone to mucosal barrier damage. Collectively, these findings demonstrate that miR-221 and miR-222 are an integral part of intestinal Th17 cell response that are induced after IL-23 stimulation to constrain the magnitude of proinflammatory response.

Circulatory miR-221 & miR-542 expression profiles as potential molecular biomarkers in Hepatitis C Virus mediated liver cirrhosis and hepatocellular carcinoma

Chronic hepatitis C virus (cHCV) is a leading cause for liver cirrhosis (LC) and hepatocellular carcinoma (HCC) globally. So far, there is no optimal non-invasive biomarker for diagnosing HCV associated hepatic disorders. Circulatory miRNAs have drawn great attention as potential non-invasive biomarkers in various diseases. We quantified miR-221 and miR-542 levels in the plasma of 153 Egyptian patients (38 healthy controls (HC), 36 cHCV, 39 HCV-LC and 40 HCV mediated HCC groups) using qRT-PCR. All diseased groups exhibited significant upregulation in miR-221 expression (P < 0.001) with an increasing trend towards late stages (HCV-LC+HCV-HCC) as compared to early stages (cHCV). MiR-221 could significantly discriminate HCC patients from cHCV and HCV-LC with (AUC=0.698; P = 0.002) and (AUC=0.644; P = 0.032) respectively. Furthermore, miR-221 could significantly discriminate between HCC and non-HCC groups (AUC=0.670, P<0.001). HCV-LC & cHCV groups showed significant upregulation in miR-542 with remarkable downregulation in HCC group (P = 0.004). MiR-542 exhibited diagnostic power of (AUC=0.640; P = 0.044) and (AUC= 0.644; P = 0.040) for discriminating HCV-LC from HCC and cHCV groups respectively. Both miR-221 and miR-542 were significantly upregulated in cirrhotic group (HCV-LC) (P = 0.046 and P = 0.002 respectively) as compared to non-cirrhotic group (cHCV+HC). Combining both miRNAs in a panel significantly improved diagnostic performance as follows; HC and HCC (AUC=0.714, P < 0.001); HCC and LC (AUC=0.714, P = 0.001); HC and LC (AUC=0.710, P = 0.002) and also cHCV and HCC (AUC=0.672, P = 0.006). In conclusion, both miR-221 & miR-542 could stand as a standalone biomarker for staging various HCV associated disorders. Combining them would greatly enhance their diagnostic potential.

Peptidylarginine Deiminase Inhibitor Application, Using Cl-Amidine, PAD2, PAD3 and PAD4 Isozyme-Specific Inhibitors in Pancreatic Cancer Cells, Reveals Roles for PAD2 and PAD3 in Cancer Invasion and Modulation of Extracellular Vesicle Signatures

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies with limited survival rate. Roles for peptidylarginine deiminases (PADs) have been studied in relation to a range of cancers with roles in epigenetic regulation (including histone modification and microRNA regulation), cancer invasion, and extracellular vesicle (EV) release. Hitherto though, knowledge on PADs in PDAC is limited. In the current study, two PDAC cell lines (Panc-1 and MiaPaCa-2) were treated with pan-PAD inhibitor Cl-amidine as well as PAD2, PAD3, and PAD4 isozyme-specific inhibitors. Effects were assessed on changes in EV signatures, including EV microRNA cargo (miR-21, miR-126, and miR-221), on changes in cellular protein expression relevant for pancreatic cancer progression and invasion (moesin), for mitochondrial housekeeping (prohibitin, PHB), and gene regulation (deiminated histone H3, citH3). The two pancreatic cancer cell lines were found to predominantly express PAD2 and PAD3, which were furthermore expressed at higher levels in Panc-1, compared with MiaPaCa-2 cells. PAD2 isozyme-specific inhibitor had the strongest effects on reducing Panc-1 cell invasion capability, which was accompanied by an increase in moesin expression, which in pancreatic cancer is found to be reduced and associated with pancreatic cancer aggressiveness. Some reduction, but not significant, was also found on PHB levels while effects on histone H3 deimination were variable. EV signatures were modulated in response to PAD inhibitor treatment, with the strongest effects observed for PAD2 inhibitor, followed by PAD3 inhibitor, showing significant reduction in pro-oncogenic EV microRNA cargo (miR-21, miR-221) and increase in anti-oncogenic microRNA cargo (miR-126). While PAD2 inhibitor, followed by PAD3 inhibitor, had most effects on reducing cancer cell invasion, elevating moesin expression, and modulating EV signatures, PAD4 inhibitor had negligible effects and pan-PAD inhibitor Cl-amidine was also less effective. Compared with MiaPaCa-2 cells, stronger modulatory effects for the PAD inhibitors were observed in Panc-1 cells, which importantly also showed strong response to PAD3 inhibitor, correlating with previous observations that Panc-1 cells display neuronal/stem-like properties. Our findings report novel PAD isozyme regulatory roles in PDAC, highlighting roles for PAD isozyme-specific treatment, depending on cancer type and cancer subtypes, including in PDAC.

MEK1 Inhibitor Combined with Irradiation Reduces Migration of Breast Cancer Cells Including miR-221 and ZEB1 EMT Marker Expression

Simple Summary

Combined chemotherapy and radiotherapy are an effective treatment for invasive breast cancer. However, some studies suggest that such interventions may increase the risk of metastasis. Cell metastatic behavior is highly dependent on RAS-RAF-MEK pathway and its downstream target activation, including miR-221 overexpression and epithelial-to-mesenchymal transition (EMT). By using MEK1 inhibitor (TAK-733) in combination with radiation therapy for breast cancer cells, significant decrease in migration capacity, including reduction of miR-221 and EMT (ZEB1) marker expression was observed. miR-221 holds great potential as therapeutic biomarker and target for new drug developments, however more insight into efficiency of miR-221 inhibition needs to be followed in the future.

Abstract

The miR-221 expression is dependent on the oncogenic RAS-RAF-MEK pathway activation and influences epithelial-to-mesenchymal transition (EMT). The Cancer Genome Atlas (TCGA) database analysis showed high gene significance for ZEB1 with EMT module analysis and miR-221 overexpression within the triple-negative breast cancer (TNBC) and HER2+ subgroups when compared to luminal A/B subgroups. EMT marker expression analysis after MEK1 (TAK-733) inhibitor treatment and irradiation was combined with miR-221 and ZEB1 expression analysis. The interaction of miR-221 overexpression with irradiation and its influence on migration, proliferation, colony formation and subsequent EMT target activation were investigated. The results revealed that MEK1 inhibitor treatment combined with irradiation could decrease the migratory potential of breast cancer cells including reduction of miR-221 and corresponding downstream ZEB1 (EMT) marker expression. The clonogenic survival assays revealed that miR-221 overexpressing SKBR3 cells were more radioresistant when compared to the control. Remarkably, the effect of miR-221 overexpression on migration in highly proliferative and highly HER2-positive SKBR3 cells remained constant even upon 8 Gy irradiation. Further, in naturally miR-221-overexpressing MDA-MB-231 cells, the proliferation and migration significantly decrease after miR-221 knockdown. This leads to the assumption that radiation alone is not reducing migration capacity of miR-221-overexpressing cells and that additional factors play an important role in this context. The miR-221/ZEB1 activity is efficiently targeted upon MEK1 inhibitor (TAK-733) treatment and when combined with irradiation treatment, significant reduction in migration of breast cancer cells was shown.

Podocyte-derived extracellular vesicles mediate renal proximal tubule cells dedifferentiation via microRNA-221 in diabetic nephropathy

Podocyte injury is a key event in the initiation of Diabetic nephropathy (DN). Tubulointerstitium, especially the proximal tubule has been regarded as a target of injury. In the present study, we showed that podocytes induced dedifferentiation of proximal tubular epithelial cells(PTECs) in high-glucose conditions and extracellular vesicles (EVs) mediates the interaction. Then we extracted and identified these EVs derived from podocytes as exosome, further, the EVs induced PTECs dedifferentiation. Total microRNA(miRNA) expression of podocyte-derived EVs was extracted and miR-221 expression was remarkably increased. By making use of the miRNA gain- and loss-of-function approaches, we observed that miR-221 mediated PTECs dedifferentiation. In addition, a dual-luciferase reporter assay confirmed that miR-221 direct target DKK2, which was an inhibitor of Wnt signaling, and overexpression of miR-221 significantly resulted in β-catenin nuclear accumulation. Moreover, we regulated the expression of β-catenin and demonstrated that miR-221 in EVs mediated proximal tubule cells injury through Wnt/β-catenin signaling. Furthermore, inhibition of miR-221 in diabetic mice reversed the abnormal expression of PTECs dedifferentiation related protein. These findings provide unique insights in the mechanisms of proximal tubule cell injury in diabetic nephropathy.

MicroRNA-221 Promotes Cell Proliferation and Inhibits Apoptosis in Osteosarcoma Cells by Directly Targeting FBXW11 and Regulating Wnt Signaling

BACKGROUND AND OBJECTIVES

MicroRNAs play a crucial role in the progression of various cancers, and microRNA-221 (miR-221) has been observed to be significantly overexpressed in osteosarcoma (OS) cells. FBXW11, a vital F-box protein of the ubiquitin-proteasome system, mediates the proliferation and survival of cancer cells by targeting multiple substrates for degradation. FBXW11 inhibits OS growth and metastasis by antagonizing the β-catenin/Wnt signaling pathway. Therefore, we hypothesized that miR-221 targets FBXW11 to mediate Wnt signaling and promote OS proliferation.

METHODS

In this study, we demonstrated the increased expression of miR-221 and FBXW11 in OS tissues and cell lines by real-time polymerase chain reaction (RT-PCR). Moreover, to elucidate the regulatory mechanism(s) of miR-221 and FBXW11 in progression, cell viability and apoptosis were analyzed by the MTT assay and flow cytometry, respectively.

RESULTS

The results showed that the overexpression of miR-221 in OS cells dramatically promoted cell growth and cell cycle progression, and inhibited apoptosis, whereas miR-221 inhibitors conversely inhibited proliferation and promoted apoptosis in OS cells. The data also showed that FBXW11 directly targeted miR-221 and miR-221 regulated OS cell proliferation and apoptosis by binding to FBXW11. We further confirmed that miR-221 targeted FBXW11 to promote proliferation and inhibit apoptosis in OS cell lines by inhibiting Wnt signaling.

INTERPRETATION AND CONCLUSIONS

Overall, our study revealed a functional mechanism for miR-221 in OS. Further studies will elucidate its role in the progression of OS and inhibiting miR-221 may represent a useful treatment strategy.

Emerging role of miRNAs as liquid biopsy markers for prediction of glioblastoma multiforme prognosis

Serum miRNAs (miRs) have gained consideration as encouraging molecular markers for cancer diagnosis and prediction of prognosis. The authors aimed to identify the exact role of miR-17-5p, miR-125b, and miR-221 among glioblastoma multiforme (GBM) patients before and after standard treatment, and correlate their expression with survival pattern. The study included 25 GBM patients and 20 healthy controls. Serum miR-17-5p, miR-125b, and miR-221 expression were analyzed before and after treatment using quantitative real-time polymerase chain reaction (qPCR). The diagnostic efficacy for the tested miRs was evaluated using the receiver operating characteristic (ROC) curve, and the relation of miRs expression versus clinical criteria for GBM was assessed. Patients' survival patterns were examined versus miRs expression levels. A significant difference was reported between miRs expression among the enrolled individuals. Both miR-17-5p and miR-221 reported significant elevations in GBM patients who: are above 60 years old, underwent biopsy resection, have a non-frontal lesion, with tumor size above 5 cm, and with performance status equals 2 according to the Eastern Cooperative Oncology Group (ECOG) Performance Status. With regard to miR-125b, a significant difference was detected according to surgery strategy, primary lesion of the tumor, and ECOG status. MiRs levels were significantly decreased for GBM patients after treatment. Survival patterns demonstrated an increase in miR-17-5p, miR-125b, and miR-221 in GBM patients with worse progression-free survival and among those with worse overall survival. Detection of serum miR-17-5p, miR-125b, and miR-221 aids in the prediction of prognosis and response to treatment strategy for GBM patients.

Plasma-Derived miRNA-222 as a Candidate Marker for Papillary Thyroid Cancer

We analyzed five miRNA molecules (miR-221; miR-222; miR-146b; miR-21; miR-181b) in the plasma of patients with papillary thyroid cancer (PTC), nodular goiter (NG) and healthy controls (HC) and evaluated their diagnostic value for differentiation of PTC from NG and HC. Preoperative PTC plasma miRNA expression (n = 49) was compared with plasma miRNA in the HC group (n = 57) and patients with NG (n = 23). It was demonstrated that miR-221; miR-222; miR-146b; miR-21 and miR-181b were overexpressed in preoperative PTC plasma samples compared to HC (p < 0.0001; p < 0.0001; p < 0.0001; p < 0.0001; p < 0.002; respectively). The upregulation in tumor tissue of these miRNAs was consistent with The Cancer Genome Atlas Thyroid Carcinoma dataset. A significant decrease in miR-21; miR-221; miR-146b and miR-181b expression was observed in the plasma of PTC patients after total thyroidectomy (p = 0.004; p = 0.001; p = 0.03; p = 0.036; respectively). The levels of miR-222 were significantly higher in the preoperative PTC compared to the NG group (p = 0.004). ROC curve (receiver operating characteristic curve) analysis revealed miR-222 as a potential marker in distinguishing PTC from NG (AUC 0.711; p = 0.004). In conclusion; circulating miR-222 profiles might be useful in discriminating PTC from NG.

lncRNA NR4A1AS Upregulates miR-221 Through Demethylation to Promote Cell Proliferation in Oral Squamous Cell Carcinoma

Background

Cell proliferation of oral squamous cell carcinoma (OSCC) is precisely regulated with a cascade of genes and pathways. Previous studies have identified NR4A1 as an oncogene and plays a crucial role in colorectal cancer development and progression. This study was performed to investigate the potential interaction between lncRNA NR4A1AS and miR-221 and how their interaction is modulated in periodontitis.

Patients and Methods

Research subjects of this study included 62 OSCC patients. Cell transfection and RT-qPCR were applied to detect the expression levels of NR4A1AS and miR-221. Methylation-specific PCR (MSP) was carried out to determine the demethylation of miR-221 by NR4A1AS. CCK-8 assay was used to detect the proliferation of OSCC cells with the overexpression of NR4A1AS or/and overexpression of miR-221.

Results

In this study, we observed that NR4A1AS was upregulated in tumor tissue samples of OSCC, and its high expression levels were significantly correlated with poor survival in patients with OSCC. In addition, miR-221 was significantly down-regulated in OSCC tumors. NR4A1AS and miR-221 were significantly and positively correlated in OSCC tumors but not in non-dysplastic tissue. In OSCC cells, overexpression of NR4A1AS led to upregulation of miR-221 and decreased the methylation of miR-221 gene. However, overexpression of miR-221 did not affect the expression of NR4A1AS in OSCC cells. In addition, overexpression of NR4A1AS or miR-221 increased the proliferation rate of OSCC cells.

Conclusion

This study is the first to report that NR4A1AS is upregulated in OSCC. Moreover, we also propose that miR-221 is modulated by NR4A1AS through demethylation and the upregulation of NR4A1AS or miR-221 promotes the proliferation of OSCC cells, which suggests that anti-NR4A1AS might be a perspective approach for the therapy of OSCC.

MicroRNA-221: A Fine Tuner and Potential Biomarker of Chronic Liver Injury

The last decade has witnessed significant advancements in our understanding of how small noncoding RNAs, such as microRNAs (miRNAs), regulate disease progression. One such miRNA, miR-221, has been shown to play a key role in the progression of liver fibrosis, a common feature of most liver diseases. Many reports have demonstrated the upregulation of miR-221 in liver fibrosis caused by multiple etiologies such as viral infections and nonalcoholic steatohepatitis. Inhibition of miR-221 via different strategies has shown promising results in terms of the suppression of fibrogenic gene signatures in vitro, as well as in vivo, in independent mouse models of liver fibrosis. In addition, miR-221 has also been suggested as a noninvasive serum biomarker for liver fibrosis and cirrhosis. In this review, we discuss the biology of miR-221, its significance and use as a biomarker during progression of liver fibrosis, and finally, potential and robust approaches that can be utilized to suppress liver fibrosis via inhibition of miR-221.

MiR-221/SIRT1/Nrf2 signal axis regulates high glucose induced apoptosis in human retinal microvascular endothelial cells

Background

Diabetic retinopathy (DR) is a serious symptom associated with diabetes and could cause much suffer to patients. MiR-221, SIRT1 and Nrf2 were associated with apoptosis and proliferation and their expression were altered in DR patients. However, their roles and regulatory mechanisms in human retinal microvascular endothelial cells (hRMEC) were not clear.

Methods

Expression of mRNA was detected by qRT-PCR. Protein expression was detected by Western blot. Interaction between miR-221 and SIRT1 was predicted by bioinformatics analysis and validated by dual-luciferase reporter assay. We analyzed the viability and apoptosis of hRMEC by MTT assay and FACS assay, respectively.

Results

High glucose (HG) treatment enhanced expression of miR-221 and inhibited expression of SIRT1 and Nrf2. MiR-221 overexpression promoted apoptosis under HG condition. Moreover, miR-221 directly interacted with mRNA of SIRT1 and inhibited SIRT1 expression in hRMEC, through which miR-221 inhibited Nrf2 pathway and induced apoptosis of hRMEC.

Conclusion

Our data demonstrated that miR-221/SIRT1/Nrf2 signal axis could promote apoptosis in hRMEC under HG conditions. This finding could provide theoretical support for future studies and may contribute to development of new treatment options to retard the process of DR development.

circPAN3 exerts a profibrotic role via sponging miR-221 through FoxO3/ATG7-activated autophagy in a rat model of myocardial infarction

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of mortality worldwide. Cardiac fibrosis is the scarring process occurs commonly with CVDs impairing the function and structure of heart. Herein, we investigated the role of circPAN3 in the pathogenesis of cardiac fibrosis.

METHODS

A rat myocardial infarction (MI) model was constructed to evaluate the role of circPAN3. Expression of circPAN3 in MI was determined, and si-circPAN3 was applied to verify its profibrotic effects. With an in vitro model, cardiac fibroblasts were stimulated by transforming growth factor beta 1 (TGFβ1). Immunofluorescent staining was employed to assess the fibrosis-related markers, as well as autophagy activity. CCK-8 and transwell assays were performed to determine cell proliferation and migration. Luciferase reporter assay and RNA pull-down were subjected to verify the interaction of circPAN3/miR-221. The enrichment of FoxO3 on the promoter region of ATG7 was detected using CHIP assay.

RESULTS

Elevated circPAN3 was found in rat MI heart tissue, of which knockdown attenuated cardiac fibrosis after MI. In an in vitro model exposing with TGFβ1, increasing cell proliferation and migration were observed, whereas these effects were abolished by circPAN3 knockdown, as well as autophagy activity. miR-221 was identified as a target to be involved in circPAN3-mediated cardiac fibrosis after MI. miR-221 negatively regulated FoxO3, thus causing the inhibition of ATG7 transcription. The regulatory network of circPAN3/miR-221/FoxO3/ATG7 in cardiac fibrosis was further determined in vivo.

CONCLUSION

circPAN3 exhibited profibrotic effects during autophagy-mediated cardiac fibrosis via miR-221/FoxO3/ATG7 axis, which may serve as potential biomarkers for cardiac fibrosis therapeutics.

Metformin inhibits angiogenesis of endothelial progenitor cells via miR-221-mediated p27 expression and autophagy

Aim: To explore the underlying mechanisms of metformin on the angiogenic capacity of endothelial progenitor cells (EPCs). Results: EPC growth and miR-221 expression decreased concentration-dependence with metformin, and a negative correlation was observed between miR-221 expression and metformin concentration (p < 0.001). miR-221 overexpression using a mimic decreased the metformin-mediated angiogenic effects in EPCs (p < 0.01). Metformin increased p27 and LC3II expression and AMP-activated protein kinase (AMPK) phosphorylation, and decreased p62 expression, while miR-221 overexpression reversed the effects of metformin. Additionally, AMPK inhibition by compound C reversed the increase in p27 and LC3II levels and AMPK phosphorylation or miR-221 siRNA treatment. Conclusion: Metformin inhibits the angiogenic capacity of EPCs. The underlying mechanism involves AMPK-mediated autophagy pathway activity and increases miR-221-mediated p27 expression.

MicroRNA-221 Modulates Airway Remodeling via the PI3K/AKT Pathway in OVA-Induced Chronic Murine Asthma

Background

Airway remodeling is one of the most important pathological features of chronic asthma. This study aimed to determine whether microRNA-221 (hereafter, miR-221) can affect airway remodeling in a mouse model of ovalbumin (OVA)-induced chronic asthma.

Methods

Adeno-associated viruses (AAVs) “Bearing miR-221 sponges” were used to downregulate miR-221 in asthmatic mice. Staining with hematoxylin and eosin (H&E), Masson trichrome, and periodic acid–Schiff reagent was used to assess histological changes. The affected signaling pathway in mouse airway smooth muscle cells (ASMCs) was also identified by gene chip technology. A PI3K/AKT-inhibitor (LY294002) was used to confirm the role of the pathway in ASMCs.

Results

The inhibition of miR-221 in a murine asthma model was found to reduce airway hyper-responsiveness, mucus metaplasia, airway inflammation, and airway remodeling (p < 0.05). Furthermore, miR-221 was found to regulate collagen deposition in the extracellular matrix (ECM) of ASMCs. Bioinformatics analysis and western blot analysis confirmed that the PI3K-AKT pathway was involved in ECM deposition in ASMCs.

Conclusion

miR-221 might play a crucial role in the mechanism of remodeling via the PI3K/AKT pathway in chronic asthma and it could be considered as a potential target for developing therapeutic strategies.

lncRNA LEF1-AS1 Promotes Proliferation and Induces Apoptosis of Non-Small-Cell Lung Cancer Cells by Regulating miR-221/PTEN Signaling

Introduction

LEF1-AS1 is a characterized oncogenic lncRNA in oral cancer. Analysis of TCGA dataset revealed the upregulation of LEF1-AS1 in non-small-cell lung cancer (NSCLC). This study was therefore carried out to investigate the involvement of LEF1-AS1 in NSCLC.

Methods

A total of 62 NSCLC patients were included to collect paired cancer and non-tumor tissues. RT-qPCR was performed to measure levels of LEF1-AS1 and miR-221 expression. Transient transfections were performed to explore the interactions between LEF1-AS1, miR-221 and PTEN. Cell proliferation and apoptosis were analyzed by cell proliferation assay and cell apoptosis assay, respectively.

Results

We found that LEF1-AS1 was upregulated in NSCLC patients. In addition, expression of LEF1-AS1 was negatively correlated with the expression of PTEN but positively correlated with the expression of miR-221 in NSCLC tissue samples. In NSCLC cells, overexpression of LEF1-AS1 led to downregulated expression of PTEN but upregulated expression of miR-221, which can directly target PTEN. Overexpression of LEF1-AS1 and miR-221 promoted cancer cell proliferation and inhibited apoptosis. PTEN played an opposite role and reduced the effects of overexpressing LEF1-AS1 and miR-221.

Conclusion

LEF1-AS1 may promote the proliferation and induce apoptosis of NSCLC cells by regulating miR-221/PTEN signaling.

Downregulation of HMGA1 Mediates Autophagy and Inhibits Migration and Invasion in Bladder Cancer via miRNA-221/TP53INP1/p-ERK Axis

MicroRNAs (miRNAs) have been implicated in regulating the development and metastasis of human cancers. MiR-221 is reported to be an oncogene in multiple cancers, including bladder cancer (BC). Deregulation of autophagy is associated with multiple human malignant cancers. Whether and how miR-221 regulates autophagy and how miR-221 has been regulated in BC are poorly understood. This study explored the potential functions and mechanisms of miR-221 in the autophagy and tumorigenesis of BC. We showed that the downregulation of miR-221 induces autophagy via increasing TP53INP1 (tumor protein p53 inducible nuclear protein 1) and inhibits migration and invasion of BC cells through suppressing activation of extracellular signal-regulated kinase (ERK). Furthermore, the expression of miR-221 is regulated by high-mobility group AT-hook 1 (HMGA1) which is overexpressed in BC. And both miR-221 and HMGA1 are correlated with poor patient survival in BC. Finally, the downregulation of HMGA1 suppressed the proliferative, migrative, and invasive property of BC by inducing toxic autophagy via miR-221/TP53INP1/p-ERK axis. Collectively, our findings demonstrate that the downregulation of miR-221 and HMGA1 mediates autophagy in BC, and both of them are valuable therapeutic targets for BC.