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

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

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

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

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

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

The miRNA-21-5p Payload in Exosomes from M2 Macrophages Drives Tumor Cell Aggression via PTEN/Akt Signaling in Renal Cell Carcinoma.

M2 macrophages in the tumor microenvironment are important drivers of cancer metastasis. Exosomes play a critical role in the crosstalk between different cells by delivering microRNAs or other cargos. Whether exosomes derived from pro-tumorigenic M2 macrophages (M2-Exos) could modulate the metastatic behavior of renal cell carcinoma (RCC) is unclear. This study found that M2-Exos promotes migration and invasion in RCC cells. Inhibiting miR-21-5p in M2-Exos significantly reversed their pro-metastatic effects on RCC cells in vitro and in the avian embryo chorioallantoic membrane in vivo tumor model. We further found that the pro-metastatic mechanism of miR-21-5p in M2-Exos is by targeting PTEN-3'UTR to regulate PTEN/Akt signaling. Taken together, our results demonstrate that M2-Exos carries miR-21-5p promote metastatic features of RCC cells through PTEN/Akt signaling. Reversing this could serve as a novel approach to control RCC metastasis.

Hypoxia-responsive miRNA-21-5p inhibits Runx2 suppression by targeting SMAD7 in MC3T3-E1 cells.

Sustained hypoxia inhibits osteogenesis and osteoblast differentiation by downregulating the expression of runt-related transcription factor 2 (Runx2). MicroRNAs (miRNAs) have been shown to regulate osteogenesis and osteoblast differentiation. In the present study, we profiled miRNAs, with microRNA array and quantitative real-time polymerase chain reaction (RT-PCR) methods, in mouse osteoblast (MC3T3-E1) cells under hypoxia. Then, we investigated regulation by miRNA-21-5p on the expression of Runx2 and other osteoblast differentiation-associated markers via gain-of-function and loss-of-function strategies. We found that expression of miRNA-21-5p, miRNA-210-5p, and other eight miRNAs was upregulated significantly in hypoxia-treated MC3T3-E1 cells. miRNA-21-5p overexpression downregulated the expression of the mRNA and protein of suppressor of mothers against decapentaplegic (SMAD7) markedly, the 3'-untranslated region (3'-UTR) of which was highly homologous with the miRNA-21-5p sequence. miRNA-21-5p overexpression upregulated the protein expression of Runx2 in hypoxia-treated MC3T3-E1 cells, although mRNA expression of Runx2 and other osteoblast differentiation-associated molecules (eg, osteocalcin, procollagen type 1 amino-terminal propeptide, P1NP) were not regulated by it; such upregulation was SMAD7-dependent. In conclusion, hypoxia-responsive miRNA-21-5p promoted Runx2 expression (at least in part) by targeting the 3'-UTR and downregulating SMAD7 expression. Our study suggests a protective role of miRNA-21-5p in promoting osteoblast differentiation under hypoxia.

Dysregulated Serum MiRNA Profile and Promising Biomarkers in Dengue-infected Patients.

OBJECTIVES: Pathological biomarkers and mechanisms of dengue infection are poorly understood. We investigated a new serum biomarker using miRNAs and performed further correlation analysis in dengue-infected patients. METHODS: Expression levels of broad-spectrum miRNAs in serum samples from three patients with dengue virus type 1 (DENV-1) and three healthy volunteers were separately analyzed using miRNA PCR arrays. The expressions of the five selected miRNAs were verified by qRT-PCR in the sera of 40 DENV-1 patients and compared with those from 32 healthy controls. Receiver operating characteristic (ROC) curve and correlation analyses were performed to evaluate the potential of these miRNAs for the diagnosis of dengue infection. RESULTS: MiRNA PCR arrays revealed that 41 miRNAs were upregulated, whereas 12 miRNAs were down-regulated in the sera of DENV-1 patients compared with those in healthy controls. Among these miRNAs, qRT-PCR validation showed that serum hsa-miR-21-5p, hsa-miR-590-5p, hsa-miR-188-5p, and hsa-miR-152-3p were upregulated, whereas hsa-miR-146a-5p was down-regulated in dengue-infected patients compared with healthy controls. ROC curves showed serum hsa-miR-21-5p and hsa-miR-146a-5p could distinguish dengue-infected patients with preferable sensitivity and specificity. Correlation analysis indicated that expression levels of serum hsa-miR-21-5p and hsa-miR-146a-5p were negative and positively correlated with the number of white blood cells and neutrophils, respectively. Functional analysis of target proteins of these miRNAs in silico indicated their involvement in inflammation and cell proliferation. CONCLUSION: Dengue-infected patients have a broad "fingerprint" profile with dysregulated serum miRNAs. Among these miRNAs, serum hsa-miR-21-5p, hsa-miR-146a-5p, hsa-miR-590-5p, hsa-miR-188-5p, and hsa-miR-152-3p were identified as promising serum indicators for dengue infection.

MiRNA-21-5p induces chicken hepatic lipogenesis by targeting NFIB and KLF3 to suppress the PI3K/AKT signaling pathway.

The liver plays a critical role in metabolic activity and is the body's first immune barrier, and maintaining liver health is particularly important for poultry production. MicroRNAs (miRNAs) are involved in a wide range of biological activities due to their capacity as posttranscriptional regulatory elements. A growing body of research indicates that miR-21-5p plays a vital role as a modulator of liver metabolism in various species. However, the effect of miR-21-5p on the chicken liver is unclear. In the current study, we discovered that the fatty liver had high levels of miR-21-5p. Then the qPCR, Western blot, flow cytometry, enzyme-linked immunosorbent assay, dual-luciferase, and immunofluorescence assays were, respectively, used to determine the impact of miR-21-5p in the chicken liver, and it turned out that miR-21-5p enhanced lipogenesis, oxidative stress, and inflammatory responses, which ultimately induced hepatocyte apoptosis. Mechanically, we verified that miR-21-5p can directly target nuclear factor I B (NFIB) and kruppel-like factor 3 (KLF3). Furthermore, our experiments revealed that the suppression of NFIB promoted apoptosis and inflammation, and the KLF3 inhibitor accelerated lipogenesis and enhanced oxidative stress. Furthermore, the cotransfection results suggest that the PI3K/AKT pathway is also involved in the process of miRNA-21-5p-mediate liver metabolism regulation. In summary, our study demonstrated that miRNA-21-5p plays a role in hepatocyte lipogenesis, oxidative stress, inflammation, and apoptosis, via targeting NFIB and KLF3 to suppress the PI3K/AKT signal pathway in chicken.

miR-21-5p is a typical noncoding RNA that could inhibit messenger RNA expression by targeting the 3ʹ-untranslated region to participate in fatty liver-related disease formation and progression. We demonstrated that miRNA-21-5p plays a role in hepatocyte lipogenesis, oxidative stress, inflammation, and apoptosis, via targeting nuclear factor I B and kruppel-like factor 3 to suppress the PI3K/AKT signal pathway in chicken. This research established the regulatory network mechanisms of miR-21-5p in chicken hepatic lipogenesis and fatty liver syndrome.

Tracheal epithelial cell-exosome-derived MiR-21-5p inhibits alveolar macrophage pyroptosis to resist pulmonary bacterial infection through PIK3CD-autophagy pathway.

AIMS: Structural cells play an important role in regulating immune cells during infection. Our aim was to determine whether structural porcine tracheal epithelial cells (PTECs) can regulate alveolar macrophages (AMs) to prevent bacterial pneumonia, explore the underlying mechanism(s) and therapeutic target. MATERIALS AND METHODS: Actinobacillus pleuropneumoniae (APP) was used as the model strain for infection studies. Small RNA sequencing was used to identify differentially abundant exosome-derived miRNAs. The role of PTECs exosome-derived miR-21-5p in regulating AMs autophagy, pyroptosis, reactive oxygen species (ROS) was determined using RT-qPCR, western-blotting, flow cytometry, immunohistochemistry. Luciferase reporter assays were conducted to identify potential binding targets of miR-21-5p. The universality of miR-21-5p action on resistance to bacterial pulmonary infection was demonstrated using Klebsiella pneumoniae or Staphylococcus aureus in vitro and in vivo infection models. KEY FINDINGS: MiR-21-5p was enriched in PETCs-derived exosomes, which protected AMs against pulmonary bacterial infection. Mechanistically, miR-21-5p targeted PIK3CD, to promote autophagy of AMs, which reduced the pyroptosis induced by APP infection via inhibiting the over-production of ROS, which in turn suppressed the over-expression of pro-inflammatory cytokines, and increased bacterial clearance. Importantly, the protective effect and mechanism of miR-21-5p were universal as they also occurred upon challenge with Klebsiella pneumoniae and Staphylococcus aureus. SIGNIFICANCE: Our data reveals miR-21-5p can promote pulmonary resistance to bacterial infection by inhibiting pyroptosis of alveolar macrophages through the PIK3CD-autophagy-ROS pathway, suggesting PIK3CD may be a potential therapeutic target for bacterial pneumonia.

Serum levels of miRNA-21-5p in vitiligo patients and effects of miRNA-21-5p on SOX5, beta-catenin, CDK2 and MITF protein expression in normal human melanocytes.

BACKGROUND: Epigenetics of vitiligo was evaluated in few studies. In particular, the role of miR-21, a microRNA involved in various processes, including melanogenesis, was never investigated. OBJECTIVE: Evaluation of serum levels of miR-21-5p in vitiligo patients and miR-21-5p effects on melanogenesis. METHODS: We measured serum levels of miR-21-5p in 40 patients affected by nonsegmental vitiligo and 40 sex- and age-matched healthy controls. Next, normal human melanocytes were transfected with miR-21-5p to study the effects of this microRNA, which targeted some proteins involved in melanogenesis pathway like SOX5, beta-catenin, cyclin-dependent kinase 2 (CDK2), and MITF. RESULTS: The expression of miR-21-5p in vitiligo patients was 3.6-4454.4 fold (mean 990.4 ± 1397.9) higher than in controls. The relative expression of miR-21-5p was directly and significantly correlated with disease severity, defined by VASI (Vitiligo Area and Severity Index) score (Rho = 0.89, p = 10-7), but not other individual or clinical characteristics. In the second part of the study, a significant reduction of SOX5, beta-catenin and CDK2 protein expression and increase of MITF protein expression was observed in cultured melanocytes after 24 h trasfection with miR-21-5p. CONCLUSION: According to literature, miR-21-5p upregulation and consequent SOX5 downregulation should upregulate melanogenesis, while vitiligo is characterized by skin depigmentation. Our results suggest that current knowledge of the pathogenesis of vitiligo is probably incomplete. Clinical manifestations could result from an altered balance between metabolic pathways with contrasting effects. In this view, miR-21-5p upregulation might be a tentative compensation mechanism. Further studies appear necessary to confirm and better understand our results and their importance.

Apigenin inhibits the growth of colorectal cancer through down-regulation of E2F1/3 by miRNA-215-5p.

BACKGROUND: Apigenin (API) is a naturally occurring plant-derived flavone, which is abundantly present in common fruits and vegetables, and shows little or no toxicity of daily diet. The treatment of colorectal cancer is limited by high recurrence rate and multidrug resistance. PURPOSE: The purpose of this study was to explore the potential therapeutic effect and possible mechanisms of API on colorectal cancer cells. METHODS: Cell proliferation and apoptosis of human colon cancer cell line HCT116 was assessed after API treatment. A comprehensive transcriptome profile of API-treated HCT116 cells was acquired by high-throughput sequencing. The regulation of miRNA215-5p and E2F1/3 were identified by bioinformatics analyses. An inhibitor of miRNA215-5p, inhibitor 215, was applied to confirm the role of this microRNA played in the anti-cancer effect of API. Luciferase reporter gene assay was performed to identify targeting relationship between miRNA215-5p and E2F1/3. RESULT: API significantly promoted cell apoptosis and anti-proliferation of HCT116 cells in a dose-dependent manner. Bioinformatics analyses identified several altered miRNAs among which the expression of miRNA-215-5p showed markedly increased. Meanwhile, the expression of E2F1 and E2F3 was decreased by API, which was associated with miRNA215-5p. Luciferase reporter gene assay showed miRNA-215-5p could directly bind to 3' UTR of E2F1/3. Inhibition of miRNA-215-5p significantly inhibited apoptosis and cell cycle arrest at G0/G1 phase induced by API. CONCLUSIONS: The result of this study confirmed the anti-cancer effect of API on human colorectal cancer cells and investigated the underlying mechanism by a comprehensive transcriptome profile of API-treated cells.

Integrated analysis identifies low microRNA-215 expression as associated with a poor prognosis of patients with colorectal cancer through the IKß-α signaling pathway.

BACKGROUND: miRNA expression data on colorectal cancer (CRC) are constantly updated. Therefore, integrated analysis of these datasets prior to experiments is necessary in translational medicine and oncology research. Abnormal low expression of hsa-miRNA-215-5p (miR-215) is detected in several cancer types, but the role of miR-215 in CRC remains unclear. Therefore, the aim of this work was to identify the expression and role of miR-215 involved in CRC. METHODS: An integrated analysis of 4 sets of miRNA microarray data of CRC in GEO was implemented. The low expression of miR-215 in CRC was confirmed by TCGA datasets. In addition, frozen tissue and paired formalin-fixed paraffin-embedded samples were collected from 214 CRC patients who underwent CRC surgery at the Affiliated Hospital of Jiangnan University, China, and used as an independent clinical validation study. Furthermore, colon cancer cells HCT116 and SW480 transfected with miR-215 mimic/inhibitor were used to evaluate its mechanism of action and to perform experiments to confirm our results obtained from human samples. RESULTS: CRC patients with a decreased miR-215 expression in adenocarcinoma tissues had a significantly poor prognosis with lower cumulative survival as revealed by the TCGA-COAD dataset. In our 214 CRC patients cohort study this result was confirmed and it was also found that low miR-215 expression was inversely correlated with the expression of IKß-α. Downregulation of miR-215 in HCT116 and SW480 cells resulted in an upregulation of TRAF5 and TAK1 protein expression, and interfered with IKß-α protein expression. Furthermore, with the inhibition of miR-215, important Epithelial-Mesenchymal Transition (EMT) biomarker proteins were significantly upregulated in HCT116 and SW480 cells. Moreover, an inhibition was obtained using miR-215-mimic. CONCLUSIONS: Our integrated microRNA dataset approach identified miR-215 as an independent factor associated with the prognosis of CRC patients. In addition, our results demonstrated that miR-215 might be considered as a potential biomarker for poor prognosis in CRC patients and its role as a potent suppressor of IKß-α and TRAF5.

MicroRNA-21-5p promotes proliferation of gastric cancer cells through targeting SMAD7.

BACKGROUND: MicroRNAs could target multiple genes by regulating the translation or degradation of mRNAs, and are involved in functions such as signal transduction pathways affecting the physiological functions of normal or tumor cells. METHODS: In this study, the expressions of miRNA-21-5p in gastric cancer tissues and SGC-7901 cells were analyzed, and the effects of miRNA-21-5p on cell proliferation, migration, invasion, and apoptosis and the expressions of target proteins SMADs in SGC-7901 cells were evaluated. Inflammatory factors interleukin 1ß and tumor necrosis factor α in siRNA-transfected SGC-7901 cells were determined by enzyme-linked immunosorbent assay. RESULTS: MiRNA-21-5p was consistently upregulated in gastric cancer tissues and SGC-7901 cells compared to normal tissues or cells. The knockdown of miRNA-21-5p with antisense oligonucleotides suppressed cell proliferation, migration, and invasion as well as inflammatory response, and promoted cell apoptosis and SMAD7 expression. CONCLUSION: These results indicate SMAD7 may mediate the oncogenic properties of miRNA-21-5p in gastric cancer, and miRNA-21-5p would be a promising strategy for the treatment of gastric cancer.

MiR-21-5p, miR-34a, and human telomerase RNA component as surrogate markers for cervical cancer progression.

OBJECTIVE: This study aimed to demonstrate the predictive value of miR-21-5p, miR-34a, and human telomerase RNA component (hTERC) in cervical cancer (CC) development and evaluated their potential possibility for future clinical applications. METHODS: Specimens were collected from the normal cervix, cervical intraepithelial neoplasia (CIN) I, CIN II/III, cervical squamous cell carcinoma. Cytological evaluations and histopathologic examinations were conducted in all subjects, along with the assessment of human papillomavirus (HPV) DNA. The expression levels of the miR-21-5p and miR-34a were detected by RT-PCR. hTERC amplification was detected by dual-color interphase fluorescence in situ hybridization (FISH). Then miRNA, hTERC expressions were compared with the cytological and histologic examination. RESULTS: Compared to that in the benign samples, the expression of miR-21-5p and miR-34a in abnormal samples was significantly upregulated and downregulated, gradually corresponding to the severity of cervical lesions (P < 0.05). There was a trend toward an increasing amplification of hTERC with the increasing severity of cervical lesions. miR-21-5p and miR-34a expression, and hTERC amplification were more specific than HPV positivity in differentiating low-grade cervical disorders from high-grade ones (P < 0.05). CONCLUSIONS: MiR-21-5p upregulation, miR-34a downregulation, and hTERC amplification were associated with the aggressive progression of CC, which suggests that miR-21-5p, miR-34a and hTERC might serve as surrogate markers for CC progression and potential molecular targets for blockage of the development of CC.