Role of miR‐218‐GREM1 axis in epithelial‐mesenchymal transition of oral squamous cell carcinoma: An in vivo and vitro study based on microarray data

Oral squamous cell carcinoma (OSCC) is a prevalent cancer that develops in the head and neck area and has high annual mortality despite optimal treatment. microRNA‐218 (miR‐218) is a tumour inhibiting non‐coding RNA that has been reported to suppress the cell proliferation and invasion in various cancers. Thus, our study aims to determine the mechanism underlying the inhibitory role of miR‐218 in OSCC. We conducted a bioinformatics analysis to screen differentially expressed genes in OSCC and their potential upstream miRNAs. After collection of surgical OSCC tissues, we detected GREM1 expression by immunohistochemistry, RT‐qPCR and Western blot analysis, and miR‐218 expression by RT‐qPCR. The target relationship between miR‐218 and GREM1 was assessed by dual‐luciferase reporter gene assay. After loss‐ and gain‐of‐function experiments, OSCC cell proliferation, migration and invasion were determined by MTT assay, scratch test and Transwell assay, respectively. Expression of TGF‐β1, Smad4, p21, E‐cadherin, Vimentin and Snail was measured by RT‐qPCR and Western blot analysis. Finally, effects of miR‐218 and GREM1 on tumour formation and liver metastasis were evaluated in xenograft tumour‐bearing nude mice. GREM1 was up‐regulated, and miR‐218 was down‐regulated in OSCC tissues, and GREM1 was confirmed to be the target gene of miR‐218. Furthermore, after up‐regulating miR‐218 or silencing GREM1, OSCC cell proliferation, migration and invasion were reduced. In addition, expression of TGF‐β signalling pathway‐related genes was diminished by overexpressing miR‐218 or down‐regulating GREM1. Finally, up‐regulated miR‐218 or down‐regulated GREM1 reduced tumour growth and liver metastasis in vivo. Taken together, our findings suggest that the overexpression of miR‐218 may inhibit OSCC progression by inactivating the GREM1‐dependent TGF‐β signalling pathway.     

MiR‐103‐3p targets the m6A methyltransferase METTL14 to inhibit osteoblastic bone formation

Impaired osteoblast function is involved in osteoporosis, and microRNA (miRNA) dysregulation may cause abnormal osteoblast osteogenic activity. However, the influence of miRNA on osteoblast activity and the underlying mechanisms remain elusive. In this study, miR‐103‐3p was found to be negatively correlated with bone formation in bone specimens from elderly women with fractures and ovariectomized (OVX) mice. Additionally, miR‐103‐3p directly targeted Mettl14 to inhibit osteoblast activity, and METTL14‐dependent N⁶‐methyladenosine (m⁶A) methylation inhibited miR‐103‐3p processing by the microprocessor protein DGCR8 and promoted osteoblast activity. Moreover, miR‐103‐3p inhibited bone formation in vivo, and therapeutic inhibition of miR‐103‐3p counteracted the decreased bone formation in OVX mice. Further, METTL14 was negatively correlated with miR‐103‐3p but positively correlated with bone formation in bone specimens from elderly women with fractures and OVX mice. Collectively, our results highlight the critical roles of the miR‐103‐3p/METTL14/m⁶A signaling axis in osteoblast activity, identifying this axis as a potential target for ameliorating osteoporosis.     

METTL3/N6‐methyladenosine/ miR‐21‐5p promotes obstructive renal fibrosis by regulating inflammation through SPRY1/ERK/NF‐κB pathway activation

Renal fibrosis induced by urinary tract obstruction is a common clinical occurrence; however, effective treatment is lacking, and a deeper understanding of the mechanism of renal fibrosis is needed. Previous studies have revealed that miR‐21 impacts liver and lung fibrosis progression by activating the SPRY1/ERK/NF‐kB signalling pathway. However, whether miR‐21 mediates obstructive renal fibrosis through the same signalling pathway has not been determined. Additionally, studies have shown that N6‐methyladenosine (m⁶A) modification‐dependent primary microRNA (pri‐microRNA) processing is essential for maturation of microRNAs, but its role in the maturation of miR‐21 in obstructive renal fibrosis has not yet been investigated in detail. To address these issues, we employed a mouse model of unilateral ureteral obstruction (UUO) in which the left ureters were ligated for 3, 7 and 14 days to simulate the fibrotic process. In vitro, human renal proximal tubular epithelial (HK‐2) cells were transfected with plasmids containing the corresponding sequence of METTL3, miR‐21‐5p mimic or miR‐21‐5p inhibitor. We found that the levels of miR‐21‐5p and m⁶A modification in the UUO model groups increased significantly, and as predicted, the SPRY1/ERK/NF‐kB pathway was activated by miR‐21‐5p, confirming that miR‐21‐5p plays an important role in obstructive renal fibrosis by enhancing inflammation. METTL3 was found to play a major catalytic role in m⁶A modification in UUO mice and drove obstructive renal fibrosis development by promoting miR‐21‐5p maturation. Our research is the first to demonstrate the role of the METTL3‐m⁶A‐miR‐21‐5p‐SPRY1/ERK/NF‐kB axis in obstructive renal fibrosis and provides a deeper understanding of renal fibrosis.     

METTL3 promotes IL‐1β–induced degeneration of endplate chondrocytes by driving m6A‐dependent maturation of miR‐126‐5p

METTL3 is an important regulatory molecule in the process of RNA biosynthesis. It mainly regulates mRNA translation, alternative splicing and microRNA maturation by mediating m6A‐dependent methylation. Interleukin 1β (IL‐1β) is an important inducer of cartilage degeneration that can induce an inflammatory cascade reaction in chondrocytes and inhibit the normal biological function of cells. However, it is unclear whether IL‐1β is related to METTL3 expression or plays a regulatory role in endplate cartilage degeneration. In this study, we found that the expression level of METTL3 and methylation level of m6A in human endplate cartilage with different degrees of degeneration were significantly different, indicating that the methylation modification of m6A mediated by METTL3 was closely related to the degeneration of human endplate cartilage. Next, through a series of functional experiments, we found that miR‐126‐5p can play a significant role in IL‐1β–induced degeneration of endplate chondrocytes. Moreover, we found that miR‐126‐5p can inhibit the PI3K/Akt signalling pathway by targeting PIK3R2 gene, leading to the disorder of cell vitality and functional metabolism. To further determine whether METTL3 could regulate miR‐126‐5p maturation, we first confirmed that METTL3 can bind the key protein underlying pri‐miRNA processing, DGCR8. Additionally, when METTL3 expression was inhibited, the miR‐126‐5p maturation process was blocked. Therefore, we hypothesized that METTL3 can promote cleavage of pri‐miR‐126‐5p and form mature miR‐126‐5p by combining with DGCR8.     

MicroRNA‐148a‐3p suppresses epithelial‐to‐mesenchymal transition and stemness properties via Wnt1‐mediated Wnt/β‐catenin pathway in pancreatic cancer

Although miR‐148a‐3p has been reported to function as a tumour suppressor in various cancers, the molecular mechanism of miR‐148a‐3p in regulating epithelial‐to‐mesenchymal transition (EMT) and stemness properties of pancreatic cancer (PC) cells remains to be elucidated. In the present study, we demonstrated that miR‐148a‐3p expression was remarkably down‐regulated in PC tissues and cell lines. Moreover, low expression of miR‐148a‐3p was associated with poorer overall survival (OS) in patients with PC. In vitro, gain‐of‐function and loss‐of‐function experiments showed that miR‐148a‐3p suppressed EMT and stemness properties as well as the proliferation, migration and invasion of PC cells. A dual‐luciferase reporter assay demonstrated that Wnt1 was a direct target of miR‐148a‐3p, and its expression was inversely associated with miR‐148a‐3p in PC tissues. Furthermore, miR‐148a‐3p suppressed the Wnt/β‐catenin pathway via down‐regulation of Wnt1. The effects of ectopic miR‐148a‐3p were rescued by Wnt1 overexpression. These biological functions of miR‐148a‐3p in PC were also confirmed in a nude mouse xenograft model. Taken together, these findings suggest that miR‐148a‐3p suppresses PC cell proliferation, invasion, EMT and stemness properties via inhibiting Wnt1‐mediated Wnt/β‐catenin pathway and could be a potential prognostic biomarker as well as a therapeutic target in PC.     

Effect of MiR‐100‐5p on proliferation and apoptosis of goat endometrial stromal cell in vitro and embryo implantation in vivo

The growth of endometrial stromal cells (ESCs) at implantation sites may be a potential factor affecting the success rate of embryo implantation. Incremental proofs demonstrated that ncRNAs (e.g. miRNAs, lncRNAs and circRNAs) were involved in various biological procedures, including proliferation and apoptosis. In this study, the role of miR‐100‐5p on proliferation and apoptosis of goat ESCs in vitro and embryo implantation in vivo was determined. The mRNA expression of miR‐100‐5p was significantly inhibited in the receptive phase (RE) rather than in the pre‐receptive phase (PE). Overexpression of miR‐100‐5p suppressed ESCs proliferation and induced apoptosis. The molecular target of MiR‐100‐5p, HOXA1, was confirmed by 3′‐UTR assays. Meanwhile, the product of HOXA1 mRNA RT‐PCR increased in the RE more than that in the PE. The HOXA1‐siRNA exerted significant negative effects on growth arrest. Instead, incubation of ESCs with miR‐100‐5p inhibitor or overexpressed HOXA1 promoted the cell proliferation. In addition, Circ‐9110 which acted as a sponge for miR‐100‐5p reversed the relevant biological effects of miR‐100‐5p. The intrinsic apoptosis pathway was suppressed in ESCs, revealing a crosstalk between Circ‐9110/miR‐100‐5p/HOXA1 axis, PI3K/AKT/mTOR, and ERK1/2 pathways. To further evaluate the progress in study on embryo implantation regulating mechanism of miR‐100‐5p in vivo, the pinopodes of two phases were observed and analysed, suggesting that, as similar as in situ, miR‐100‐5p was involved in significantly regulating embryo implantation in vivo. Mechanistically, miR‐100‐5p performed its embryo implantation function through regulation of PI3K/AKT/mTOR and ERK1/2 pathways by targeting Circ‐9110/miR‐100‐5p/HOXA1 axis in vivo.     

circRNA 001306 enhances hepatocellular carcinoma growth by up‐regulating CDK16 expression via sponging miR‐584‐5p

Circular RNAs (circRNAs) have been demonstrated to play important roles in cancer progress. However, the roles in hepatocellular carcinoma (HCC) are still unclear. Here, we found has_circRNA_001306 (circ_1306) was up‐regulated in HCC tissues and cell lines. Knockdown the expression circ_1306 significantly suppressed HCC cell proliferation and induced the cell apoptosis in vitro and in vivo. Furthermore, we identified circ_1306 could up‐regulate the expression of CDK16 by sponging miR‐584‐5p. The expression of miR‐584‐5p was decreased, and the expression of CDK16 was increased in HCC tissues and cell lines. Meanwhile, either knockdown of miR‐584‐5p or overexpression of CDK16 could suppress the HCC cell proliferation. In vivo, overexpression of miR‐584‐5p or knockdown of circ_1306 could inhibit the expression of CDK16, and suppress tumour growth. Altogether, our findings suggested that circ_1306 could promoter HCC progress by miR‐584‐5p/CDK16 axis, which provided a novel marker for HCC diagnosis and treatment.     

circ‐AKT3 aggravates renal ischaemia‐reperfusion injury via regulating miR‐144‐5p /Wnt/β‐catenin pathway and oxidative stress

Renal ischaemia‐reperfusion (RI/R) injury is one major pathological state of acute kidney injury (AKI) with a mortality rate ranking 50% to 80%. MiR‐144‐5p acts as a molecular trigger in various diseases. We presumed that miR‐144‐5p might be involved RI/R injury progression. We found that RI/R injury decreased miR‐144‐5p expression in rat models. MiR‐144‐5p downregulation promoted cell apoptosis rate and activated Wnt/β‐catenin signal in RI/R injury rats. By performing bioinformatic analysis, RIP, RNA pull‐down, luciferase reporter experiments, we found that circ‐AKT3 sponged to miR‐144‐5p and decreased its expression in RI/R injury rats. Moreover, we found that circ‐AKT3 promoted cell apoptosis rate and activated Wnt/β‐catenin signal, and miR‐144‐5p mimic reversed the promotive effect of circ‐AKT3 in rat models. We also found that circ‐AKT3 increased the oxidative stress level in rat models. In conclusion, our study suggests that the circAKT3 is involved RI/R injury progression through regulating miR‐144‐5p/Wnt/β‐catenin pathway and oxidative stress.     

Down‐regulated LINC00115 inhibits prostate cancer cell proliferation and invasion via targeting miR‐212‐5p/FZD5/Wnt/β‐catenin axis

Prostate cancer is the second most frequent malignancy in men worldwide, and its incidence is increasing. Therefore, it is urgently required to clarify the underlying mechanisms of prostate cancer. Although the long non‐coding RNA LINC00115 was identified as an oncogene in several cancers, the expression and function of LINC00115 in prostate cancer have not been explored. Our results showed that LINC00115 was significantly up‐regulated in prostate cancer tissues, which was significantly associated with a poor prognosis for prostate cancer patients. Functional studies showed that knockdown LINC00115 inhibited cell proliferation and invasion. In addition, LINC00115 served as a competing endogenous RNA (ceRNA) through sponging miR‐212‐5p to release Frizzled Family Receptor 5 (FZD5) expression. The expression of miR‐212‐5p was noticeably low in tumour tissues, and FZD5 expression level was down‐regulated with the knockdown of LINC00115. Knockdown LINC00115 inhibited the Wnt/β‑catenin signalling pathway by inhibiting the expression of FZD5. Rescue experiments further showed that LINC00115 inhibits prostate cancer cell proliferation and invasion via targeting miR‐212‐5p/ FZD5/ Wnt/β‐catenin axis. The present study provided clues that LINC00115 may be a promising novel therapeutic target for prostate cancer patients.     

Circulating miR‐19a‐3p and miR‐19b‐3p characterize the human aging process and their isomiRs associate with healthy status at extreme ages

Blood circulating microRNAs (c‐miRs) are potential biomarkers to trace aging and longevity trajectories to identify molecular targets for anti‐aging therapies. Based on a cross‐sectional study, a discovery phase was performed on 12 donors divided into four groups: young, old, healthy, and unhealthy centenarians. The identification of healthy and unhealthy phenotype was based on cognitive performance and capabilities to perform daily activities. Small RNA sequencing identified 79 differentially expressed c‐miRs when comparing young, old, healthy centenarians, and unhealthy centenarians. Two miRs, that is, miR‐19a‐3p and miR‐19b‐3p, were found increased at old age but decreased at extreme age, as confirmed by RT‐qPCR in 49 donors of validation phase. The significant decrease of those miR levels in healthy compared to unhealthy centenarians appears to be due to the presence of isomiRs, not detectable with RT‐qPCR, but only with a high‐resolution technique such as deep sequencing. Bioinformatically, three main common targets of miR‐19a/b‐3p were identified, that is, SMAD4, PTEN, and BCL2L11, converging into the FoxO signaling pathway, known to have a significant role in aging mechanisms. For the first time, this study shows the age‐related increase of plasma miR‐19a/b‐3p in old subjects but a decrease in centenarians. This decrease is more pronounced in healthy centenarians and was confirmed by the modified pattern of isomiRs comparing healthy and unhealthy centenarians. Thus, our study paves the way for functional studies using c‐miRs and isomiRs as additional parameter to track the onset of aging and age‐related diseases using new potential biomarkers.     

Circ_0067835 sponges miR‐324‐5p to induce HMGA1 expression in endometrial carcinoma cells

Endometrial cancer is a common gynaecological malignant tumour among women across the world. Circular RNAs (circRNAs) are a novel kind of non‐coding RNAs, and they can play a crucial role in multiple cancers. Nevertheless, the mechanisms of circRNAs in regulating gene expression in endometrial cancer are still unclear. Here, our work sought to focus on the role that circ_0067835 exert in progression and development of endometrial cancer cells. We observed circ_0067835 was markedly elevated in endometrial cancer. Then, changes in endometrial cancer cell (RL95‐2 and HEC‐1B) function were determined after circ_0067835 knockdown. Loss‐of‐functional assays revealed that circ_0067835 down‐regulation significantly repressed RL95‐1 and HEC‐1B cell proliferation, migration and invasion. Bioinformatics analysis, luciferase reporter experiment and RNA pull‐down assay were employed to predict and validate circ_0067835 can bind to miR‐324‐5p. Increase in miR‐324‐5p remarkably depressed the proliferation, migration and invasion of endometrial cancer cells via inhibiting high mobility group A1 (HMGA1). HMGA1 is identified as a vital prognostic biomarker in endometrial cancer. Currently, we reported circ_0067835 was positively correlated with HMGA1 in endometrial cancer. We implied that circ_0067835 was capable of sponging miR‐324‐5p and inducing its downstream target HMGA1 in vitro and in vivo. In conclusion, circ_0067835 can compete with miR‐324‐5p, resulting in HMGA1 up‐regulation, and therefore induce the development of endometrial cancer.     

Polydatin inhibits ZEB1‐invoked epithelial‐mesenchymal transition in fructose‐induced liver fibrosis

High fructose intake is a risk factor for liver fibrosis. Polydatin is a main constituent of the rhizome of Polygonum cuspidatum, which has been used in traditional Chinese medicine to treat liver fibrosis. However, the underlying mechanisms of fructose‐driven liver fibrosis as well as the actions of polydatin are not fully understood. In this study, fructose was found to promote zinc finger E‐box binding homeobox 1 (ZEB1) nuclear translocation, decrease microRNA‐203 (miR‐203) expression, increase survivin, activate transforming growth factor β1 (TGF‐β1)/Smad signalling, down‐regulate E‐cadherin, and up‐regulate fibroblast specific protein 1 (FSP1), vimentin, N‐cadherin and collagen I (COL1A1) in rat livers and BRL‐3A cells, in parallel with fructose‐induced liver fibrosis. Furthermore, ZEB1 nuclear translocation‐mediated miR‐203 low‐expression was found to target survivin to activate TGF‐β1/Smad signalling, causing the EMT in fructose‐exposed BRL‐3A cells. Polydatin antagonized ZEB1 nuclear translocation to up‐regulate miR‐203, subsequently blocked survivin‐activated TGF‐β1/Smad signalling, which were consistent with its protection against fructose‐induced EMT and liver fibrosis. These results suggest that ZEB1 nuclear translocation may play an essential role in fructose‐induced EMT in liver fibrosis by targeting survivin to activate TGF‐β1/Smad signalling. The suppression of ZEB1 nuclear translocation by polydatin may be a novel strategy for attenuating the EMT in liver fibrosis associated with high fructose diet.     

Circular RNA hsa_circ_0083756 promotes intervertebral disc degeneration by sponging miR‐558 and regulating TREM1 expression

ObjectivesIntervertebral disc degeneration (IVDD) is a leading cause of low back pain. Circular RNAs (circRNAs) have been demonstrated to exert vital functions in IVDD. However, the role and mechanism of hsa_circ_0083756 in the development of IVDD remain unclear.Materials and methodsRT‐qPCR was performed to detect expressions of hsa_circ_0083756, miR‐558 and TREM1 in nucleus pulposus (NP) tissues and cells. CCK8 assay, flow cytometry, TUNEL assay, RT‐qPCR and WB were used to clarify the roles of hsa_circ_0083756 in NP cells proliferation and extracellular matrix (ECM) formation. Bioinformatics analyses, dual‐luciferase reporter gene experiment, RNA immunoprecipitation (RIP) assay and FISH assay were performed to predict and verify the targeting relationship between hsa_circ_0083756 and miR‐558, as well as that between miR‐558 and TREM1. Ultimately, the effect of hsa_circ_0083756 on IVDD was tested through anterior disc‐puncture IVDD animal model in rats.Resultshsa_circ_0083756 was upregulated in degenerative NP tissues and cells. In vitro loss‐of‐function and gain‐of‐function studies suggested that hsa_circ_0083756 knockdown promoted, whereas hsa_circ_0083756 overexpression inhibited NP cells proliferation and ECM formation. Mechanistically, hsa_circ_0083756 acted as a sponge of miR‐558 and subsequently promoted the expression of TREM1. Furthermore, in vivo study indicated that silencing of hsa_circ_0083756 could alleviate IVDD in rats.Conclusionshsa_circ_0083756 promoted IVDD via targeting the miR‐558/TREM1 axis, and hsa_circ_0083756 may serve as a potential therapeutic target for the treatment of IVDD.     

MiR‐223‐3p inhibits rTp17‐induced inflammasome activation and pyroptosis by targeting NLRP3

The incidence of syphilis caused by Treponema pallidum subsp pallidum (T pallidum) infection is accompanied by inflammatory injuries of vascular endothelial cells. Studies have revealed that T pallidum infection could induce inflammasome activation and pyroptosis in macrophages. MicroRNA‐223‐3p (miR‐223‐3p) was reported to be a negative regulator in inflammatory diseases. The present study aimed to explore whether miR‐223‐3p regulates T pallidum‐induced inflammasome activation and pyroptosis in vascular endothelial cells, and determine the mechanisms which underlie this process. MiR‐223‐3p levels in syphilis and control samples were determined. The biological function of miR‐223‐3p in the NLRP3 inflammasome and pyroptosis was evaluated in T pallidum‐infected human umbilical vein endothelial cells (HUVECs). We observed a dramatic decrease in miR‐223‐3p levels in syphilis patients (n = 20) when compared to healthy controls (n = 20). Moreover, miR‐223‐3p showed a notable inhibitory effect on recombinant Tp17 (rTP17)‐induced caspase‐1 activation, resulting in decrease in IL‐1β production and pyroptosis, which was accompanied by the release of lactate dehydrogenase (LDH) in HUVECs. Additionally, the dual‐luciferase assay confirmed that NLRP3 is a direct target of miR‐223‐3p. Moreover, NLRP3 overexpression or knockdown largely blocked the effects of miR‐223‐3p on T pallidum‐induced inflammasome activation and pyroptosis in HUVECs. Most importantly, a notable negative correlation was observed between miR‐223‐3p and NLRP3, caspase‐1, and IL‐1β, respectively, in the serum of syphilis patients and healthy controls. Taken together, our results reveal that miR‐223‐3p targets NLRP3 to suppress inflammasome activation and pyroptosis in T pallidum‐infected endothelial cells, implying that miR‐223‐3p could be a potential target for syphilis patients.     

Down‐regulated HDAC3 elevates microRNA‐495‐3p to restrain epithelial‐mesenchymal transition and oncogenicity of melanoma cells via reducing TRAF5

MicroRNAs (miRNAs) are emerging biomarkers in biological processes and the role of miR‐495‐3p has been identified in melanoma, while the detailed molecular mechanisms remain to be further explored. We aim to explore the effect of histone deacetylase 3 (HDAC3) and miR‐495‐3p on epithelial‐mesenchymal transition (EMT) and oncogenicity of melanoma cells by regulating tumour necrosis factor receptor‐associated factor 5 (TRAF5). Levels of HDAC3, miR‐495‐3p and TRAF5 in melanoma tissues and pigmented nevus tissues were determined, and the predictive roles of HDAC3 and miR‐495‐3p in prognosis of melanoma patients were measured. The melanoma cells were screened and transfected with relative oligonucleotides and plasmids, and the expression of HDAC3, miR‐495‐3p and TRAF5, and phenotypes of melanoma cells were gauged by a series of assays. The relations between HDAC3 and miR‐495‐3p, and between miR‐495‐3p and TRAF5 were confirmed. HDAC3 and TRAF5 were increased while miR‐495‐3p was decreased in melanoma cells and tissues, and the low expression of miR‐495‐3p as well as high expression of HDAC3 indicated a poor prognosis of melanoma patients. Inhibited HDAC3 elevated miR‐495‐3p to suppress EMT and oncogenicity of melanoma cells by reducing TRAF5. HDAC3 particularly bound to miR‐495‐3p and TRAF5 was the target gene of miR‐495‐3p. Our results revealed that down‐regulated HDAC3 elevates miR‐495‐3p to suppress malignant phenotypes of melanoma cells by inhibiting TRAF5, thereby repressing EMT progression of melanoma cells. This study may provide novel targets for melanoma treatment.     

miR‐126‐5p enhances radiosensitivity of lung adenocarcinoma cells by inhibiting EZH2 via the KLF2/BIRC axis

Radiotherapy is a common method for the treatment of lung adenocarcinoma, but it often fails due to the relative non‐susceptibility of lung adenocarcinoma cells to radiation. We aimed to discuss the related mechanisms by which miR‐126‐5p might mediate radiosensitivity of lung adenocarcinoma cells. The binding affinity between miR‐126‐5p and EZH2 and between KLF2 and BIRC5 was identified using multiple assays. A549 and H1650 cells treated with X‐ray were transfected with miR‐126‐5p mimic/inhibitor, oe‐EZH2, or si‐KLF2 to detect cell biological functions and radiosensitivity. Finally, lung adenocarcinoma nude mouse models were established. miR‐126‐5p and KLF2 were poorly expressed, while EZH2 and BIRC5 were upregulated in lung adenocarcinoma tissues and cells. miR‐126‐5p targeted EZH2 to promote the KLF2 expression so as to inhibit BIRC5 activation. Both in vitro and in vivo experiments verified that elevated miR‐126‐5p inhibited cell migration and promoted apoptosis to enhance the sensitivity of lung adenocarcinoma cells to radiotherapy via the EZH2/KLF2/BIRC5 axis. Collectively, miR‐126‐5p downregulated EZH2 to facilitate the sensitivity of lung adenocarcinoma cells to radiotherapy via KLF2/BIRC5.     

Knockdown of circular RNA VANGL1 inhibits TGF‐β‐induced epithelial‐mesenchymal transition in melanoma cells by sponging miR‐150‐5p

Melanoma is one of the most aggressive and life‐threatening skin cancers, and in this research, we aimed to explore the functional role of circular RNA VANGL1 (circVANGL1) in melanoma progression. The expression levels of circVANGL1 were observed to be significantly increased in clinical melanoma tissues and cell lines. Moreover, circVANGL1 knockdown suppressed, while circVANGL1 overexpression promoted the proliferation, migration and invasion abilities of melanoma cells. Further investigations confirmed the direct binding relation between circVANGL1 and miR‐150‐5p in melanoma, and restoration of miR‐150‐5p blocked the effects of circVANGL1 overexpression in melanoma cells. We further found that circVANGL1 was up‐regulated by TGF‐β treatment, and the enhanced EMT of TGF‐β‐treated melanoma cells was blocked by circVANGL1 knockdown. In conclusion, these results indicated that circVANGL1 might serve as a promising therapeutic target for melanoma.     

LncRNA FAF attenuates hypoxia/ischaemia‐induced pyroptosis via the miR‐185‐5p/PAK2 axis in cardiomyocytes

Pyroptosis is associated with various cardiovascular diseases. Increasing evidence suggests that long noncoding RNAs (lncRNAs) have been implicated in gene regulation, but how lncRNAs participate in the regulation of pyroptosis in the heart remains largely unknown. In this study, we aimed to explore the antipyroptotic effects of lncRNA FGF9‐associated factor (FAF) in acute myocardial infarction (AMI). The expression patterns of lncRNA FAF, miR‐185‐5p and P21 activated kinase 2 (PAK2) were detected in hypoxia/ischaemia‐induced cardiomyocytes. Hoechst 33342/PI staining, lactate dehydrogenase (LDH) release assay, immunofluorescence and Western blotting were conducted to assay cell pyroptosis. The interaction between lncRNA FAF, miR‐185‐5p and PAK2 was verified by bioinformatics analysis, small RNA sequencing luciferase reporter assay and qRT‐PCR. The expression of LncRNA FAF was downregulated in hypoxic cardiomyocytes and myocardial tissues. Overexpression of lncRNA FAF could attenuate cardiomyocyte pyroptosis, improve cell viability and reduce infarct size during the procession of AMI. Moreover, lncRNA FAF was confirmed as a sponge of miR‐185‐5p and promoted PAK2 expression in cardiomyocytes. Collectively, our findings reveal a novel lncRNA FAF/miR‐185‐5p/PAK2 axis as a crucial regulator in cardiomyocyte pyroptosis, which might be a potential therapeutic target of AMI.     

MicroRNA‐411‐3p inhibits bleomycin‐induced skin fibrosis by regulating transforming growth factor‐β/Smad ubiquitin regulatory factor‐2 signalling

Skin fibrosis, which is characterized by fibroblast proliferation and increased extracellular matrix, has no effective treatment. An increasing number of studies have shown that microRNAs (miRNAs/miRs) participate in the mechanism of skin fibrosis, such as in limited cutaneous systemic sclerosis and pathological scarring. The objective of the present study was to determine the role of miR‐411‐3p in bleomycin (BLM)‐induced skin fibrosis and skin fibroblast transformation. Using Western blot analysis and real‐time quantitative polymerase chain reaction assess the expression levels of miR‐411‐3p, collagen (COLI) and transforming growth factor (TGF)‐β/Smad ubiquitin regulatory factor (Smurf)‐2/Smad signalling factors both in vitro and in vivo with or without BLM. To explore the regulatory relationship between miR‐411‐3p and Smurf2, we used the luciferase reporter assay. Furthermore, miR‐411‐3p overexpression was identified in vitro and in vivo via transfection with Lipofectamine 2000 reagent and injection. Finally, we tested the dermal layer of the skin using haematoxylin and eosin and Van Gieson''s staining. We found that miR‐411‐3p expression was decreased in bleomycin (BLM)‐induced skin fibrosis and fibroblasts. However, BLM accelerated transforming growth factor (TGF)‐β signalling and collagen production. Overexpression of miR‐411‐3p inhibited the expression of collagen, F‐actin and the TGF‐β/Smad signalling pathway factors in BLM‐induced skin fibrosis and fibroblasts. In addition, miR‐411‐3p inhibited the target Smad ubiquitin regulatory factor (Smurf)‐2. Furthermore, Smurf2 was silenced, which attenuated the expression of collagen via suppression of the TGF‐β/Smad signalling pathway. We demonstrated that miR‐411‐3p exerts antifibrotic effects by inhibiting the TGF‐β/Smad signalling pathway via targeting of Smurf2 in skin fibrosis.