MiR-21 regulating PVT1/PTEN/IL-17 axis towards the treatment of infectious diabetic wound healing by modified GO-derived biomaterial in mouse models

BACKGROUND

Diabetic foot ulcer (DFU), persistent hyperglycemia and inflammation, together with impaired nutrient and oxygen deficiency, can present abnormal angiogenesis following tissue injury such that these tissues fail to heal properly. It is critical to design a new treatment method for DFU patients with a distinct biomechanism that is more effective than current treatment regimens.

METHOD

Graphene oxide (GO) was combined with a biocompatible polymer as a kind of modified GO-based hydrogel. The characterization of our biomaterial was measured in vitro. The repair efficiency of the biomaterial was evaluated in the mouse full-skin defect models. The key axis related to diabetic wound (DW) was identified and investigated using bioinformatics analyses and practical experiments.

RESULT

In the study, we found that our modified GO-based wound dressing material is a promising option for diabetic wound. Secondly, our biomaterial could enhance the secretion of small EVs (sEVs) with more miR-21 by adipose-derived mesenchymal stem cells (AD-MSCs). Thirdly, the PVT1/PTEN/IL-17 axis was found to be decreased to promote DFU wound healing by modifying miR-21 with the discovery of PVT1 as a critical LncRNA by bioinformatics analysis and tests.

CONCLUSION

These findings could aid in the development of clinical care strategies for DFU wounds.

Lidocaine Suppresses Gastric Cancer Development Through Circ_ANO5/miR-21-5p/LIFR Axis

BACKGROUND

Lidocaine has been manifested to exert anti-tumor role in gastric cancer (GC) progression. However, the action mechanism by which Lidocaine functions in GC has not been fully elucidated.

AIM

The study aimed to reveal the molecular mechanism of Lidocaine in GC progression.

METHODS

Cell clonogenicity and viability were assessed by colony formation and methyl thiazolyl tetrazolium assays, respectively. Transwell assay was employed to detect cell migration and invasion. Flow cytometry was implemented to monitor cell apoptosis. Relative expression of circular RNA ANO5 (circ_ANO5), microRNA (miR)-21-5p and Leukemia inhibitory factor receptor (LIFR) was examined by quantitative reverse transcription-polymerase chain reaction. Western blot assay was performed to analyze the levels of LIFR and cell metastasis-related proteins. The target relationship between miR-21-5p and circ_ANO5 or LIFR was confirmed by dual-luciferase reporter assay. In addition, xenograft model was established to explore the role of Lidocaine in vivo.

RESULTS

Lidocaine inhibited cell proliferation, migration and invasion, while promoted apoptosis of GC cells. Lidocaine upregulated circ_ANO5 and LIFR expression, but downregulated miR-21-5p expression in GC cells. Additionally, expression of circ_ANO5 and LIFR was decreased, while miR-21-5p expression was increased in GC cells. Circ_ANO5 depletion or miR-21-5p overexpression attenuated Lidocaine-induced anti-proliferative and anti-metastatic effects on GC cells. Circ_ANO5 could sponge miR-21-5p, and miR-21-5p targeted LIFR. Moreover, Lidocaine suppressed the tumor growth in vivo.

CONCLUSION

Lidocaine might GC cell malignancy by modulating circ_ANO5/miR-21-5p/LIFR axis, highlighting a novel insight for GC treatment.

Exosomes derived from magnetically actuated bone mesenchymal stem cells promote tendon-bone healing through the miR-21-5p/SMAD7 pathway

Graft healing after anterior cruciate ligament reconstruction (ACLR) involves slow biological processes, and various types of biological modulations have been explored to promote tendon-to-bone integration. Exosomes have been extensively studied as a promising new cell-free strategy for tissue regeneration, but few studies have reported their potential in tendon-to-bone healing. In this study, a novel type of exosome derived from magnetically actuated (iron oxide nanoparticles (IONPs) combined with a magnetic field) bone mesenchymal stem cells (BMSCs) (IONP-Exos) was developed, and the primary purpose of this study was to determine whether IONP-Exos exert more significant effects on tendon-to-bone healing than normal BMSC-derived exosomes (BMSC-Exos). Here, we isolated and characterized the two types of exosomes, conducted in vitro experiments to measure their effects on fibroblasts (NIH3T3), and performed in vivo experiments to compare the effects on tendon-to-bone integration. Moreover, functional exploration of exosomal miRNAs was further performed by utilizing a series of gain- and loss-of-function experiments. Experimental results showed that both BMSC-Exos and IONP-Exos could be shuttled intercellularly into NIH3T3 fibroblasts and enhanced fibroblast activity, including proliferation, migration, and fibrogenesis. In vivo, we found that IONP-Exos significantly prevented peri-tunnel bone loss, promoted more osseous ingrowth into the tendon graft, increased fibrocartilage formation at the tendon-bone tunnel interface, and induced a higher maximum load to failure than BMSC-Exos. Furthermore, overexpression of miR-21-5p remarkably enhanced fibrogenesis in vitro, and SMAD7 was shown to be involved in the promotive effect of IONP-Exos on tendon-to-bone healing. Our findings may provide new insights into the regulatory roles of IONPs in IONP-Exos communication via stimulating exosomal miR-21-5p secretion and the SMAD7 signaling pathway in the fibrogenic process of tendon-to-bone integration. This work could provide a new strategy to promote tendon-to-bone healing for tissue engineering in the future.

Curcumol inhibits the growth of xenograft-tumors in mice and the biological activities of pancreatic cancer cells by regulating the miR-21-5p/SMAD7 axis

Anti-cancer effects of curcumol on various cancers have been reported previously. This study focused on investigating the role of curcumol in pancreatic cancer from the molecular perspective. The survival of pancreatic cancer patients with high or low expression of miR-21-5pand the target gene of miR-21-5pwere analyzed by bioinformatics. MiR-21-5p expression in cancer tissues was analyzed by RT-qPCR. Anxenograft-tumor BALB/c nude mice model was established and pancreatic cancer cells were cultured. Later, the mice and cells were further treated with curcumol. The tumor size and weightas well as mice body weight were recorded. The viability, proliferation, migration, and invasion of the cells were evaluated by MTT, colony formation, and transwell assays, respectively. The expressions of molecules in the xenograft-tumor tissues or cells were detected by immunohistochemical assay, Western blot, or RT-qPCR. MiR-21-5p was high-expressed in pancreatic cancer tissues and patients with high expression of miR-21-5p had poor survival. Curcumol inhibited the xenograft-tumor size, tumor weight, and PCNA and miR-21-5p expressions while promoting Cleaved caspase-3 expression in xenograft-tumor tissues. Curcumol inhibited the viability, proliferation, migration, invasion, and miR-21-5p expression, but increased SMAD7 expression in cancer cells. MiR-21-5p overexpression reversed the effect of curcumol on cancer cells, and decreased the E-cadherin expression while elevating the expressions of PCNA, N-cadherin, Vimentin, p-SMAD2, and p-SMAD3 in curcumol-treated cells. The overexpression of SMAD7, a target gene of miR-21-5p, reversed the effect of miR-21-5p on curcumol-treated cells. Curcumol inhibited growth of xenograft-tumors and the biological activities of pancreatic cancer cells by regulating the miR-21-5p/SMAD7 axis.

Fuzheng Kang' ai decoction inhibits cell proliferation, migration and invasion by modulating mir-21-5p/human phosphatase and tensin homology deleted on chromosome ten in lung cancer cells

OBJECTIVE

To elucidate the potential molecular mechanism by which Fuzheng Kang'ai decoction (, FZKA) inhibits proliferation, migration, and invasion of lung cancer cells.

METHODS

Varying FZKA concentrations were used to manage lung cancer cells (A549 and PC9). We employed: cell counting kit-8 (CCK-8) and plate clone for-mation assays to examine the cell viability; flow cytometry (FCM) to analyze the cycle arrest; transwell and wound-healing assays to assess the cell invasion and migration, respectively. Further, a quantitative real-time polymerase chain reaction (qRT-PCR) assay was adopted to evaluate the miR-21-5p expression. For protein expression analysis, we employed the Western blot technique. Recombinant miR-21-5p overexpression adenovirus vector harboring GFP was constructed and transfected into A549 and PC9, after which we explored the effect of FZKA on miR-21-5p overexpression.

RESULTS

Notably, treatment with FZKA inhibited viability, clone-formation ability, invasion, and migration of lung cancer cells. Mechanistically, FZKA markedly suppressed miR-21-5p expression but elevated the human phosphatase and tensin homology deleted on chromosome ten (PTEN) protein level in both A549 and PC9 cells. Over-expression of miR-21-5p lowered PTEN protein expression. Besides, overexpressed miR-21-5p levels with adenovirus antagonized FZKA-upregulated PTEN protein expression.

CONCLUSION

The present study demonstrates how FZKA modulates cell biological behaviors, for instance, it impedes the proliferation by upregulating PTEN expression with miR-21-5p as the target. These findings unveil the potential novel molecular mechanisms from the microRNA aspect by which FZKA suppresses the growth of human lung cancer cells.

miR-21-5p serves as a promoter in renal cell carcinoma progression through ARHGAP24 downregulation

Renal cell carcinoma (RCC) is a highly recurrent aggressive tumor. This study works for the regulation of miR-21-5p on RCC cell functions and novel ideas for therapies of RCC. Isoform expression quantification data were offered by The Cancer Genome Atlas Kidney Renal Clear Cell Carcinoma (TCGA-KIRC) to investigate differentially expressed miRNAs. The way miR-21-5p works on biological functions of RCC was examined with MTT and Transwell assays. The downstream targets of miR-21-5p were predicted using bioinformatics analysis. The binding of two researched objects was verified by the dual-luciferase method. TCGA data manifested a considerably high level of miR-21-5p in RCC tissue, while ARHGAP24 was significantly lowly expressed. miR-21-5p bound ARHGAP24 and stimulated RCC cell functions, whereas ARHGAP24 mimic could reverse such promotion. This work observed miR-21-5p, a stimulator in RCC, and it deteriorated this cancer via repressing its downstream target gene ARHGAP24 expression.

Bone mesenchymal stem cells (BMSCs)-derived exosomal microRNA-21-5p regulates Kruppel-like factor 3 (KLF3) to promote osteoblast proliferation in vitro

Bone mesenchymal stem cells (BMSCs)-derived exosomes (Exos) play important roles in osteoporosis, while the regulation of microRNA (miR)-21-5p remains unclear. The BMSCs-derived exosomes were isolated from femoral bone marrow of trauma patients, which were then used to stimulate human osteoblasts (hFOB1.19 cells). The miR-21-5p mimic or inhibitor was transfected into BMSCs to overexpress or knockdown miR-21-5p. The functions of miR-21-5p in osteoporosis were assessed by cell counting kit-8 (CCK-8) assay, alkaline phosphatase (ALP) staining and alizarin red staining assays. We found that BMSCs-derived exosomes could enhance proliferation, osteoblastic differentiation and ALP activity of hFOB1.19 cells. BMSCs-derived exosomes with upregulated miR-21-5p could further enhance these protective impacts compared with that in BMSCs-derived exosomes, while BMSCs-derived exosomes with downregulated miR-21-5p reduced these cell phenotypes. MiR-21-5p could directly bind to the 3’-untranslated region (UTR) of Kruppel-like factor 3 (KLF3), and knockdown of KLF3 obviously attenuated these inhibitory effects of BMSCs-derived exosomes with downregulated miR-21-5p on osteoblastic differentiation and ALP activity of hFOB1.19 cells. In summary, BMSCs-derived exosomal miR-21-5p improved osteoporosis through regulating KLF3, providing a potential therapeutic strategy for osteoporosis.

PABPC1-induced stabilization of IFI27 mRNA promotes angiogenesis and malignant progression in esophageal squamous cell carcinoma through exosomal miRNA-21-5p

BACKGROUND

Emerging evidence has demonstrated that RNA-binding protein dysregulation is involved in esophageal squamous cell carcinoma (ESCC) progression. However, the role of poly (A) binding protein cytoplasmic 1 (PABPC1) in ESCC is unclear. We therefore aimed to explore the functions and potential mechanisms of PABPC1 in ESCC progression.

METHODS

PABPC1 expression was characterized using immunohistochemistry and qRT-PCR in ESCC tissues and cell lines. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays were used to detect histone acetylation in the promoter region of PABPC1. A series of in vitro and in vivo assays were further applied to elucidate the functions and underlying molecular mechanisms of PABPC1 in ESCC angiogenesis and malignant procession.

RESULTS

PABPC1 expression was upregulated in ESCC tissues compared with in normal esophageal epithelial tissues. Elevated PABPC1 expression was correlated with tumor cell differentiation and poor prognosis in patients. Sp1 and p300 cooperated to increase the level of H2K37ac in the PABPC1 promoter. Functionally, PABPC1 overexpression enhanced esophageal squamous cell proliferation and invasion by activating the IFN/IFI27 signaling pathway. PABPC1 interacted with eIF4G to increase the stability of IFI27 mRNA by competing with RNA exosomes in ESCC. Furthermore, PABPC1/IFI27 could increase miR-21-5p expression to enable exosomal delivery of miR-21-5p to human umbilical vein endothelial cells to increase angiogenesis via inhibiting CXCL10.

CONCLUSION

PABPC1 plays a critical role in ESCC malignant progression by interacting with eIF4G to regulate IFI27 mRNA stability and promote angiogenesis via exosomal miR-21-5p/CXCL10. Taken together, our results suggest that PABPC1 is a promising therapeutic target for ESCC.

Circ_SAR1A regulates the malignant behavior of lung cancer cells via the miR-21-5p/TXNIP axis

Background

Lung cancer is one of the most common malignancies globally and a significant component of cancer‐related deaths. The lack of early diagnosis accounts for detecting approximately 75% of cancer patients at an intermediate to an advanced stage, with a low 5‐year survival rate. Therefore, a more comprehensive understanding of the molecular mechanisms of lung cancer development is necessary to find reliable and effective therapeutic and diagnostic biomarkers.

Methods

circ_SAR1A, miR‐21‐5p, and TXNIP in lung cancer tissues, animal xenografts, and cell lines were validated by qRT‐PCR and western blotting analyses. RNase R digestion and nuclear/cytoplasm fractionation experiments were utilized to determine the stability and localization of circ_SAR1A in lung cancer cells. The binding between miR‐21‐5p and circ_SAR1A or TXNIP was confirmed by luciferase reporter, RNA pull‐down, Spearman's correlation, and rescue assays. CCK‐8, colony formation, flow cytometry, Transwell, and western blotting were utilized to illustrate the malignant behavior of lung cancer cells.

Results

circ_SAR1A and TXNIP were down‐regulated while miR‐21‐5p was up‐regulated in lung cancer samples and cells. circ_SAR1A was located predominantly in the cytoplasm; it inhibited lung cancer growth in vitro and in vivo by sponging to miR‐21‐5p. miR‐21‐5p silencing suppressed lung cancer malignancy by targeting TXNIP.

Conclusions

circ_SAR1A is a critical negative regulator of lung carcinogenesis. circ_SAR1A/miR‐21‐5p/TXNIP attenuation inhibited lung cancer progression, presenting an ideal diagnostic and a potential therapeutic target.

MicroRNA Regulation of Bone Marrow Mesenchymal Stem Cell Chondrogenesis: Toward Articular Cartilage

The production of a clinically useful engineered cartilage is an outstanding and unmet clinical need. High-throughput RNA sequencing provides a means of characterizing the molecular phenotype of populations of cells and can be leveraged to better understand differences among source cells, derivative engineered tissues, and target phenotypes. In this study, small RNA sequencing is utilized to comprehensively characterize the microRNA transcriptomes (miRNomes) of native human neonatal articular cartilage and human bone marrow-derived mesenchymal stem cells (hBM-MSCs) differentiating into cartilage organoids, contrasting the microRNA regulation of engineered cartilage with that of a promising target phenotype. Five dominant microRNAs are upregulated during cartilage organoid differentiation and disproportionately regulate transcription factors: miR-148a-3p, miR-140-3p, miR-27b-3p, miR-140-5p, and miR-181a-5p. Two microRNAs that dominate the miRNomes of hBM-MSCs, miR-21-5p and miR-143-3p, persist throughout the differentiation process and may limit the ability of these cells to differentiate into an engineered cartilage resembling target native articular cartilage. By using predictive bioinformatics tools and antagomir inhibition, these persistent microRNAs are shown to destabilize the mRNA of genes with known or potential roles in cartilage biology including FGF18, TGFBR2, TET1, STOX2, ARAP2, N4BP2L1, LHX9, NFIA, and RPS6KA5. These results shed light on the extent to which only a few microRNAs contribute to the complex regulatory environment of hBM-MSCs for engineered tissues. Impact statement MicroRNAs are emerging as important controlling elements in the differentiation of human bone marrow-derived mesenchymal stem cells (hBM-MSCs). By using a robust bioinformatic approach and further validation in vitro, here we provide a comprehensive characterization of the microRNA transcriptomes (miRNomes) of a commonly studied and clinically promising source of multipotent cells (hBM-MSCs), a gold standard model of in vitro chondrogenesis (hBM-MSC-derived cartilage organoids), and an attractive in vivo target phenotype for clinically useful engineered cartilage (neonatal articular cartilage). These analyses highlighted a specific set of microRNAs involved in the chondrogenic program that could be manipulated to acquire a more robust articular cartilage-like phenotype. This characterization provides researchers in the cartilage tissue engineering field a useful atlas with which to contextualize microRNA involvement in complex differentiation pathways.

Clinical Significance of miR-21-5p in Predicting Occurrence and Progression of Uremic Vascular Calcification in Patients with End-Stage Renal Disease

PURPOSE

Vascular calcification (VC) is a common complication of end-stage renal disease (ESRD). This study aimed to examine changes in the expression of miR-21-5p in ESRD patients with VC and to explore its clinical value in predicting the occurrence and progression of uremic VC.

MATERIALS AND METHODS

120 ESRD patients were divided into patients without VC group (n=38) and patients with VC group (n=82). All patients were followed up for 2 years to evaluate VC progression. qRT-PCR was used to detect serum miR-21-5p levels. Receiver operating characteristic curves were constructed to assess diagnostic value. Kaplan-Meier and log-rank methods were utilized to calculate associations between VC progression and risk factors.

RESULTS

Serum miR-21-5p levels were significantly higher in ESRD patients with VC than in those without VC and increased progressively with increasing disease severity. Serum miR-21-5p levels were able to distinguish patients with VC from those without VC, with an area under the curve value of 0.883, a sensitivity of 81.7%, and a specificity of 84.2%. After 2 years of follow-up, miR-21-5p expression had increased in patients with worse VC severity, compared with those with stable VC severity. Patients with high miR-21-5p levels were more likely to develop more severe VC, indicating an association between miR-21-5p and VC progression (log-rank p=0.002). Multivariable Cox regression analysis suggested that serum miR-21-5p is an independent predictive factor of VC progression in ESRD patients (hazard ratio=2.064, 95% confidence interval=1.225-3.478, p=0.006).

CONCLUSION

miR-21-5p is overexpressed in the serum of ESRD patients with VC. Our results suggest that overexpression of miR-21-5p is closely associated with VC progression.

UTMD-mediated delivery of miR-21-5p inhibitor suppresses the development of lung cancer

BACKGROUND

Ultrasound-targeted microbubble destruction (UTMD) is a new type of gene delivery technology. MiR-21-5p was highly expressed in a variety of cancers. In this paper, miR-21-5p inhibitor was transfected into lung cancer cells by UTMD to observe its role in lung cancer.

METHODS

StarBase was used to analyze the miR-21-5p expression in lung cancer patients and its relationship with the prognosis of the patients. MiR-21-5p expression in lung cancer tissues or cell lines was determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Effects of gradient concentration (0, 5, 10, 20, 30%) of SonoVue or gradient mechanical index (MI) (0, 0.5, 1, 1.5, 2 W/cm²) on the cell viability were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The targeting relationship between miR-21-5p and B-cell translocation gene 2 (BTG2) was predicted by TargetScan and confirmed by dual-luciferase reporter assay, while the expressions of the two genes were determined by qRT-PCR. Through liposome transfection or UTMD transfection, the effects of miR-21-5p/BTG2 on the biological behaviors of lung cancer cells, the size of xenograft tumors and the expressions of ki67 and miR-21-5p were measured by qRT-PCR, western blot, cell function experiments and immunohistochemistry, respectively.

RESULTS

MiR-21-5p expression was upregulated in lung cancer, which was associated with a poor prognosis. The optimal ultrasound conditions were 10% SonoVue concentration and 1 W/cm². UTMD transfection exerted a stronger effect than liposome transfection. MiR-21-5p promoted cell viability, proliferation and migration yet suppressed apoptosis by targeting BTG2. MiR-21-5p inhibitor reduced the size and volume of xenograft tumor and the expressions of ki67 and miR-21-5p in xenograft tumor tissues.

CONCLUSION

UTMD-mediated miR-21-5p inhibitor can more effectively suppress the development of lung cancer.

Epigenetic inactivation of ACAT1 promotes epithelial-mesenchymal transition of clear cell renal cell carcinoma

BACKGROUND

Acetyl-CoA acyltransferase 1 (ACAT1) is a key enzyme catalyzing the production of mitochondrial ketone bodies. We have shown that ACAT1 is down-regulated in kidney renal clear cell carcinoma (KIRC) previously.

OBJECTIVE

To investigate the reasons for downregulation of ACAT1 in KIRC and explore the underlying mechanisms involved in metastatic inhibition regulated by ACAT1.

METHODS

The Gene Expression Omnibus (GEO) database was queried for meta-analysis of ACAT1 mRNA expression in KIRC. The UALCAN website was used to compare the methylation levels of the ACAT1 promoter region in KIRC and normal tissues. RT-qPCR was used to quantitate ACAT1 transcription levels. The GCBI and Tarbase V.8 databases were used to predict miRNAs that may target the mRNA of ACAT1. The correlation between mRNA expression of ACAT1, MMP7 (matrix metallopeptidase 7), CDH1 (E-cadherin), EpCAM (epithelial cell adhesion molecule), and VIM (vimentin) was analyzed. Extracellular MMP7 protein was quantitated using an ELISA assay.

RESULTS

The methylation level of the ACAT1 promoter region in KIRC was significantly higher than that in the normal kidney tissues. The ACAT1 mRNA expression in the KIRC cell lines was restored after treatment with 5-aza-dC (p < 0.05). MiR-21-5p is a conserved microRNA targeting ACAT1. It is expressed at a significantly higher level in KIRC than in normal tissues (p < 0.001). MiR-21-5p miRNA expression negatively correlates with ACAT1 mRNA expression. The expression of miR-21-5p is higher at the T3-T4 stages and in the histologic grades G3-G4. Patients with high miR-21-5p expression tended to have lower overall survival, suggesting that miR-21-5p could serve as a potentially valuable diagnostic biomarker for KIRC (AUC = 0.957; p < 0.001). A mimetic of miR-21-5p inhibited the expression of ACAT1 mRNA and protein. In addition, ACAT1 mRNA expression positively correlates with CDH1 and EpCAM but is negatively correlated with VIM. Overexpression of ACAT1 suppresses the secretion of MMP7 in KIRC cells.

CONCLUSION

Expression of ACAT1 in KIRC is controlled at two levels, firstly by the hypermethylation of the ACAT1 promoter region and secondly by overexpression of miR-21-5p. Downregulation of ACAT1 expression correlates with epithelial-mesenchymal transition (EMT).

Co-treatment with miR-21-5p inhibitor and Aurora kinase inhibitor reversine suppresses breast cancer progression by targeting sprouty RTK signaling antagonist 2

Numerous studies have reported the regulatory effects of miR-21-5p and reversine in human breast cancer (HBC). However, the mechanism of reversine and miR-21-5p has not been fully investigated in HBC. The aim of the current study was to assess the mechanism of action of reversine, with or without miR-21-5p, in HBC progression. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot results confirmed the upregulation of miR-21-5p and downregulation of sprouty RTK signaling antagonist 2 (SPRY2) in HBC. Bioinformatics analysis and luciferase assay identified the correlation between miR-21-5p and SPRY2. Cell function experiment results indicated a decrease in migration, proliferation, and invasion of HBC cells treated with miR-21-5p inhibitor and reversine; however, an increase in apoptosis was observed in these cells. Apoptotic ability was more enhanced and migration, proliferation, and invasion were more impaired in HBC cells treated with both miR-21-5p inhibitor and reversine than in those treated individually with either inhibitors. SPRY2, downstream of miR-21-5p, participated in HBC progression with reversine. Overall, our study proved that combining the miR-21-5p inhibitor with reversine produced a synergistic effect by regulating SPRY2, thereby limiting HBC progression. This knowledge might offer insights into the clinical therapy of HBC.

Hsa_circ_0008259 modulates miR-21-5p and PDCD4 expression to restrain osteosarcoma progression

BACKGROUND

Osteosarcoma (OS) is one of the most common primary bone tumors in children and adolescents. However, the molecular mechanism of OS tumorigenesis is still little known. Circular RNA (circRNA) is a key player in the progression of many cancers. This study is performed to decipher the role and mechanism of circ_0008259 in the progression of OS.

METHODS

A differentially expressed circRNA, circ_0008259, was screened out by analyzing the expression profile of circRNA in OS tissue. Circ_0008259, miR-21-5p and programmable cell death 4 (PDCD4) mRNA expression levels in OS tissues and cells were detected by qRT-PCR. Cell viability, metastatic potential and apoptosis were evaluated by cell counting kit-8 assay, Transwell and flow cytometry. The targeting relationship between circ_0008259 and miR-21-5p, and miR-21-5p and PDCD4 mRNA was analyzed and probed by bioinformatics analysis and dual-luciferase reporter assay, RNA-binding protein immunoprecipitation assay and RNA-pull down assay. The regulatory effects of circ_0008259 and miR-21-5p on PDCD4 protein expression in OS cells were detected by Western blot assay.

RESULTS

Circ_0008259 expression and PDCD4 expression were down-regulated and miR-21-5p expression was elevated in the OS tissues and cells. Functional experiments showed that circ_0008259 overexpression significantly inhibited the proliferation and metastatic potential of OS cells and promoted the apoptosis. Besides, PDCD4 was validated as the target gene of miR-21-5p, and circ_0008259 could competitively bind to miR-21-5p, thus up-regulating PDCD4 expression in OS cells.

CONCLUSIONS

Circ_0008259 suppresses OS progression via regulating miR-21-5p/PDCD4 axis.

Mechanism of Adipose-Derived Mesenchymal Stem Cell-Derived Extracellular Vesicles Carrying miR-21-5p in Hyperoxia-Induced Lung Injury

Hyperoxia-induced lung injury (HILI) tends to develop bronchopulmonary dysplasia. Adipose-derived mesenchymal stem cell (ADMSC)-derived extracellular vesicles (EVs) hold great promise in alleviating lung injury. This study explored the mechanism of ADMSC-EVs in HILI. ADMSC-EVs were isolated and identified. The murine and cell models of HILI were established. HILI mice and cells were pre-treated with ADMSC-EVs. The lung dry/wet ratio, pathological structure, apoptosis, and inflammation of HILI mice were measured. The viability, apoptosis, and oxidative stress of HILI cells were measured. The internalization of EVs in lung and cells was observed by fluorescence labeling. The binding relationships between miR-21-5p and SKP2, and Nr2f2 and C/EBPα were analyzed. The binding of SKP2 and Nr2f2 and the Nr2f2 ubiquitination level were detected. ADMSC-EVs exerted preventive effects on HILI mice, evidenced by reduced lung dry/wet ratio, inflammation, and apoptosis in HILI mice. In vitro, EVs enhanced HILI cell viability and reduced apoptosis, inflammation, and oxidative stress. EVs carried miR-21-5p into lung cells to upregulate miR-21-5p expression and thereby target SKP2. SKP2 bound to Nr2f2 and promoted its ubiquitination degradation. EVs inhibited the binding of Nr2f2 and C/EBPα and further suppressed C/EBPα transcription. Collectively, ADMSC-EVs carrying miR-21-5p alleviated HILI via the SKP2/Nr2f2/C/EBPα axis. Role and mechanism of adipose-derived mesenchymal stem cell-derived extracellular vesicles in hyperoxia-induced lung injury. ADMSC-EVs upregulated miR-21-5p expression in cells by carrying miR-21-5p into lung cells, thereby promoting the binding of miR-21-5p and SKP2 mRNA, inhibiting the expression of SKP2, reducing the ubiquitination level of Nr2f2, increasing the expression of Nr2f2, promoting the binding of Nr2f2 and the C/EBPα promoter, upregulating C/EBPα mRNA level, and eventually alleviating HILI.

miR-21-5p is a Biomarker for Predicting Prognosis of Lung Adenocarcinoma by Regulating PIK3R1 Expression

Background

Lung cancer (LUCA) is one of the most prevalent human malignancies, and the leading cause of cancer-related deaths worldwide. Previous reports have shown that miR-21-5p plays a vital role in development of various tumors. Here, we explored the relationship between miR-21-5p/PIK3R1 axis and prognosis of patients with lung adenocarcinoma (LUAD).

Methods

MiRNAseq data, deposited in The Cancer Genome Atlas (TCGA) database, was downloaded and used to determine patterns of miR-21-5p expression in both LUAD and normal lung tissues. Statistical analyses and data visualization were performed using dbDEMC v3.0 platform, starBase v3.0 database and packages implemented in R software. Next, we employed TargetScan Human, miRDB and DIANA Tools databases to predict miR-21-5p target genes, then analyzed their expression patterns as well as prognostic value in LUAD.

Findings

Most human cancers overexpressed miR-21-5p. Specifically, miR-21-5p was significantly upregulated in LUAD tissues relative to normal lung tissues (P < 0.001), and this high expression was significantly correlated with poor patient prognosis (hazard ratio [HR]=1.45, P = 0.014). PIK3R1 was predicted as a miR-21-5p target gene, and both were negatively correlated (r=-0.218, P < 0.01). Notably, PIK3R1 was significantly downregulated in LUAD, relative to normal lung tissues (P < 0.01), with its overexpression significantly associated with poor prognosis of LUAD patients (HR = 0.62, P = 0.0014).

Conclusion

miR-21-5p is a potential prognostic biomarker for LUAD patients. Moreover, it might be playing a role in LUAD progression by regulating PIK3R1 expression.

CircRNA-001241 Mediates Sorafenib Resistance of Hepatocellular Carcinoma Cells by Sponging miR-21-5p and Regulating TIMP3 Expression

Hepatocellular carcinoma (HCC) is one of the major malignancies worldwide and its incidence is on the rise, closely related to advanced liver disease¹. Sorafenib chemotherapy is one of the main treatment options for patients with advanced HCC. Despite several reports on HCC multidrug resistance, the underlying regulatory mechanisms are still unclear. In this study, we found circ-001241 was significantly upregulated in HCC tissues and cells. Knockdown of circ-001241 markedly inhibited HCC cell proliferation and decreased sorafenib-resistance. More importantly, circRNA acts as a ceRNA to suppress the expression and activity of miR-21-5p, leading to the increase in TIMP3 expression. In addition, circRNA-001241 facilitated HCC sorafenib-resistance by regulating the miR-21-5p/TIMP3 axis.Taken together, our study elucidated the oncogenic role of circ-001241 in mediating sorafenib resistance in HCC, providing insights and opportunities to overcome sorafenib resistance in patients with advanced hepatocellular carcinoma.

Long non-coding RNA CASC7 suppresses malignant behaviors of breast cancer by regulating miR-21-5p/FASLG axis

Recently, it has been increasingly proved that lncRNAs are functionally involved in a majority of tumor progression. LncRNA CASC7 has also been revealed to participate in the development of several cancers as a tumor promoter or suppressor. Herein, we focus on uncovering the role and underlying molecular mechanism of CASC7 in breast cancer. Tumor tissues and the paired paracancerous tissues from the breast cancer patients were used to evaluate the level of CASC7 in breast cancer. By analyzing the CASC7 expression in breast cancer cell lines, both the expression levels of CASC7 in cancer tissues and cell lines were obviously downregulated compared to those in paired paracancerous tissues and normal human epithelial MCF10A cells. Subsequently, the construction of lentivirus overexpression system (oe-CASC7 and oe-NC) was used to elevate the expression of CASC7. A series of functional experiments were conducted to show that the cell proliferation, migration, and invasion were inhibited when CASC7 overexpressed in breast cancer cells. Meanwhile, the apoptosis of oe-CASC7 cells was induced compared to the oe-NC breast cancer cells. We further confirmed that CASC7 functions by regulating miR-21-5p/FASLG axis. Finally, a xenograft model in nude mice verified that CASC7 was a tumor suppressor in breast cancer. These results suggest that lncRNA CASC7 suppresses to malignant behaviors of breast cancer by modulating miR-21-5p/FASLG axis. Abbreviations lncRNAs: long non-coding RNAs; ceRNA: competing endogenous RNA; CASC7: cancer susceptibility candidate 7; miRNAs: MicroRNAs; MAPK10: mitogen-activated protein kinase 10; FASLG: Tumor Necrosis Factor Ligand Superfamily Member 6; FAS: Tumor Necrosis Factor Receptor Superfamily Member 6.

Serum Alpha-1-Acid Glycoprotein-1 and Urinary Extracellular Vesicle miR-21-5p as Potential Biomarkers of Primary Aldosteronism

Primary aldosteronism (PA) is the most common cause of secondary hypertension and reaches a prevalence of 6-10%. PA is an endocrine disorder, currently identified as a broad-spectrum phenotype, spanning from normotension to hypertension. In this regard, several studies have made advances in the identification of mediators and novel biomarkers of PA as specific proteins, miRNAs, and lately, extracellular vesicles (EVs) and their cargo.

Aim

To evaluate lipocalins LCN2 and AGP1, and specific urinary EV miR-21-5p and Let-7i-5p as novel biomarkers for PA.

Subjects and Methods

A cross-sectional study was performed in 41 adult subjects classified as normotensive controls (CTL), essential hypertensives (EH), and primary aldosteronism (PA) subjects, who were similar in gender, age, and BMI. Systolic (SBP) and diastolic (DBP) blood pressure, aldosterone, plasma renin activity (PRA), and aldosterone to renin ratio (ARR) were determined. Inflammatory parameters were defined as hs-C-reactive protein (hs-CRP), PAI-1, MMP9, IL6, LCN2, LCN2-MMP9, and AGP1. We isolated urinary EVs (uEVs) and measured two miRNA cargo miR-21-5p and Let-7i-5p by Taqman-qPCR. Statistical analyses as group comparisons were performed by Kruskall-Wallis, and discriminatory analyses by ROC curves were performed with SPSS v21 and Graphpad-Prism v9.

Results

PA and EH subjects have significantly higher SBP and DBP (p <0.05) than the control group. PA subjects have similar hs-CRP, PAI-1, IL-6, MMP9, LCN2, and LCN2-MMP9 but have higher levels of AGP1 (p <0.05) than the CTL&EH group. The concentration and size of uEVs and miRNA Let-7i-5p did not show any difference between groups. In PA, we found significantly lower levels of miR-21-5p than controls (p <0.05). AGP1 was associated with aldosterone, PRA, and ARR. ROC curves detected AUC for AGP1 of 0.90 (IC 95 [0.79 - 1.00], p <0.001), and combination of AGP1 and EV-miR-21-5p showed an AUC of 0.94 (IC 95 [0.85 - 1.00], p<0.001) to discriminate the PA condition from EH and controls.

Conclusion

Serum AGP1 protein was found to be increased, and miR-21-5p in uEVs was decreased in subjects classified as PA. Association of AGP1 with aldosterone, renin activity, and ARR, besides the high discriminatory capacity of AGP1 and uEV-miR-21-5p to identify the PA condition, place both as potential biomarkers of PA.

Exosomal miR-21-5p derived from bone marrow mesenchymal stem cells promote osteosarcoma cell proliferation and invasion by targeting PIK3R1

Mesenchymal stem cells (MSCs) are a class of pluripotent cells that can release a large number of exosomes which act as paracrine mediators in tumour-associated microenvironment. However, the role of MSC-derived exosomes in pathogenesis and progression of cancer cells especially osteosarcoma has not been thoroughly clarified until now. In this study, we established a co-culture model for human bone marrow-derived MSCs with osteosarcoma cells, then extraction of exosomes from induced MSCs and study the role of MSC-derived exosomes in the progression of osteosarcoma cell. The aim of this study was to address potential cell biological effects between MSCs and osteosarcoma cells. The results showed that MSC-derived exosomes can significantly promote osteosarcoma cells' proliferation and invasion. We also found that miR-21-5p was significantly over-expressed in MSCs and MSC-derived exosomes by quantitative real-time polymerase chain reaction (qRT-PCR), compared with human foetal osteoblastic cells hFOB1.19. MSC-derived exosomes transfected with miR-21-5p could significantly enhance the proliferation and invasion of osteosarcoma cells in vitro and in vivo. Bioinformatics analysis and dual-luciferase reporter gene assays validated the targeted relationship between exosomal miR-21-5p and PIK3R1; we further demonstrated that miR-21-5p-abundant exosomes derived human bone marrow MSCs could activate PI3K/Akt/mTOR pathway by suppressing PIK3R1 expression in osteosarcoma cells. In summary, our study provides new insights into the interaction between human bone marrow MSCs and osteosarcoma cells in tumour-associated microenvironment.

Circ_0027599 elevates RUNX1 expression via sponging miR-21-5p on gastric cancer progression

BACKGROUND

Increasing evidence has shown that circular RNAs (circRNAs) serve as vital regulators in tumour progression. In this study, we focused on the functions of circ_0027599 in gastric cancer (GC) progression.

METHODS

The levels of circ_0027599, runt-related transcription factor 1 (RUNX1) mRNA and microRNA-21-5p (miR-21-5p) were detected by quantitative real-time polymerase chain reaction (qRT-PCR) assay. The protein levels of RUNX1, E-Cadherin, vimentin and N-Cadherin were measured by Western blot assay. Cell viability, colony formation, metastasis and cell cycle process were evaluated by Cell Counting Kit-8 (CCK-8) assay, colony formation assay, transwell assay and flow cytometry analysis, respectively. The interaction between circ_0027599 and miR-21-5p and the interaction between miR-21-5p and RUNX1 were verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. The role of circ_0027599 in tumour growth in vivo was investigated by murine xenograft model assay.

RESULTS

Circ_0027599 and RUNX1 were downregulated in GC tissues and cells. Circ_0027599 level was associated with the overall survival of GC patients. Circ_0027599 or RUNX1 overexpression inhibited GC cell viability, colony formation, migration, invasion and cell cycle process in vitro. For mechanism analysis, circ_0027599 positively regulated RUNX1 expression via functioning as the sponge for miR-21-5p. RUNX1 inhibition reversed circ_0027599 overexpression mediated malignant behaviours of GC cells. Moreover, circ_0027599 overexpression repressed tumour growth in vivo.

CONCLUSION

Circ_0027599 overexpression repressed GC progression via modulation of miR-21-5p/RUNX1 axis, which might illumine a novel therapeutic target for GC.

miR-21-5p inhibits inflammation injuries in LPS-treated H9c2 cells by regulating PDCD4

OBJECTIVES

To explore the expression levels and the potential regulatory mechanism of miR-21-5p in LPS-treated H9c2 cells.

METHODS

The secretions of the inflammatory cytokines induced by LPS in H9c2 cells were evaluated using ELISA. We used RT-RCR and western blot to measure the relative mRNA and protein expression levels in LPS-treated H9c2 cells. CCK-8 and EdU assays showed the viability and proliferation profiles of the H9c2 cells. TUNEL assays demonstrated the apoptotic behaviors of the H9c2 cells, and a luciferase reporter analysis was used to investigate the interactions between miR-21-5p and programmed cell death protein 4 (PDCD4).

RESULTS

LPS induced damage to the H9c2 cells by reducing the cell viability and down-regulating miR-21-5p. On the other hand, miR-21-5p overexpression inhibited the LPS-induced inflammatory damage in the H9c2 cells. Moreover, PDCD4 was verified as a downstream target gene of miR-21-5p, and its expression was inhibited by the higher miR-21-5p content. Finally, miR-21-5p inhibited septic processes, and the PDCD4 overexpression rescued the miR-21-5p effect in the LPS-treated H9c2 cells.

CONCLUSION

Our findings suggest that miR-21-5p inhibits the LPS-induced progression of sepsis in H9c2 cells. Additionally, PDCD4 is a downstream target gene of miR-21-5p, and both molecules serve as potential therapeutic targets for heart sepsis patients.

Astragaloside IV attenuates hypoxia/reoxygenation injury-induced apoptosis of type II alveolar epithelial cells through miR-21-5p

We aimed to explore the role of miR-21-5p in the inhibitory effects of astragaloside IV (As-IV) on hypoxia/reoxygenation injury-induced apoptosis of type II alveolar epithelial cells. Rat type II alveolar epithelial cells RLE-6TN were cultured in vitro and randomly divided into control (C), hypoxia/reoxygenation injury (H/R), As-IV and miR-21-5p-siRNA + As-IV groups (n = 6). H/R model was established by 24 h of hypoxia and 4 h of reoxygenation. As-IV group was given 1 nmol/L As-IV and incubated for 1 h before modeling. MiR-21-5p-siRNA + As-IV group was transfected with 50 nmol/L miR-21-5p-siRNA. After 48 h, they were incubated with 1 nmol/L As-IV for 1 h before modeling. Cell viability was detected by cell counting kit-8 assay, and apoptosis rate was detected by flow cytometry. The expression levels of TLR4 and NF-κB were measured by immunofluorescence assay. The targeting relationship between miR-21-5p and TLR4 was determined by luciferase assay. Compared with H/R group, the cell viability, miR-21-5p, bax and cleaved caspase-3 expressions of As-IV group increased, apoptosis rate and Bcl-2 expression decreased, and TLR4 and NF-κB expressions were down-regulated (P < 0.05). Compared with As-IV group, the cell viability, miR-21-5p, bax and cleaved caspase-3 expressions of miR-21-5p-siRNA + As-IV group decreased, apoptosis rate and Bcl-2 expression increased, and the expressions of TLR4 and NF-κB were up-regulated (P < 0.05). As-IV up-regulates miR-21-5p expression, inhibits the TLR4/NF-κB signaling pathway and suppresses the apoptosis of type II alveolar epithelial cells during hypoxia/reoxygenation injury.

Extracellular vesicles from adipose tissue-derived stem cells alleviate osteoporosis through osteoprotegerin and miR-21-5p

Osteoporosis is one of the most common skeletal disorders caused by the imbalance between bone formation and resorption, resulting in quantitative loss of bone tissue. Since stem cell-derived extracellular vesicles (EVs) are growing attention as novel cell-free therapeutics that have advantages over parental stem cells, the therapeutic effects of EVs from adipose tissue-derived stem cells (ASC-EVs) on osteoporosis pathogenesis were investigated. ASC-EVs were isolated by a multi-filtration system based on the tangential flow filtration (TFF) system and characterized using transmission electron microscopy, dynamic light scattering, zeta potential, flow cytometry, cytokine arrays, and enzyme-linked immunosorbent assay. EVs are rich in growth factors and cytokines related to bone metabolism and mesenchymal stem cell (MSC) migration. In particular, osteoprotegerin (OPG), a natural inhibitor of receptor activator of nuclear factor-κB ligand (RANKL), was highly enriched in ASC-EVs. We found that the intravenous administration of ASC-EVs attenuated bone loss in osteoporosis mice. Also, ASC-EVs significantly inhibited osteoclast differentiation of macrophages and promoted the migration of bone marrow-derived MSCs (BM-MSCs). However, OPG-depleted ASC-EVs did not show anti-osteoclastogenesis effects, demonstrating that OPG is critical for the therapeutic effects of ASC-EVs. Additionally, small RNA sequencing data were analysed to identify miRNA candidates related to anti-osteoporosis effects. miR-21-5p in ASC-EVs inhibited osteoclast differentiation through Acvr2a down-regulation. Also, let-7b-5p in ASC-EVs significantly reduced the expression of genes related to osteoclastogenesis. Finally, ASC-EVs reached the bone tissue after they were injected intravenously, and they remained longer. OPG, miR-21-5p, and let-7b-5p in ASC-EVs inhibit osteoclast differentiation and reduce gene expression related to bone resorption, suggesting that ASC-EVs are highly promising as cell-free therapeutic agents for osteoporosis treatment.