MiR-506 inhibits PRRSV replication in MARC-145 cells via CD151

Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically important diseases of swine, which is caused by PRRS virus (PRRSV). CD151, one of PRRSV entry mediators, determines the cell susceptibility for PRRSV. Emerging evidence indicates that the host microRNAs (miRNAs) play key roles in modulating virus infection and viral pathogenesis. In the present study, targeting porcine CD151 miRNAs were identified, and their function during PRRSV infection in MARC-145 cells was further verified. We found that miR-506 could directly target porcine CD151 3′-UTR mRNA by luciferase reporter assay. Overexpression of miR-506 significantly decreased CD151 expression at both mRNA and protein levels. Furthermore, overexpression of miR-506 reduced cellular PRRSV replication and virus release in MARC-145 cells. Our results suggested that miR-506 could inhibit PRRSV replication by directly targeting PRRSV receptor of CD151 in MARC-145 cells. However, the molecular mechanisms of miR-506 and its function in vivo need further investigation.     

miR-141 suppresses proliferation and motility of gastric cancer cells by targeting HDGF

miR-141 belongs to the miR-200 family, and has been found to be associated with numerous human malignancies; however, its role in gastric cancer (GC) has not been examined in detail. Here, we validated that miR-141 was decreased in GC tissues and cell lines. Forced expression of miR-141 significantly repressed GC cell proliferation and colony formation. Furthermore, miR-141 suppressed in vitro migration and invasion of GC cells. Hepatoma-derived growth factor (HDGF) was confirmed to be a direct target of miR-141 in GC cells. The suppressive effects of miR-141 on GC cell proliferation, colony formation, in vitro migration, and invasion were partially mediated by suppressing HDGF expression. Moreover, the expression of HDGF was negatively correlated with miR-141 in GC tissues. Our data suggest that miR-141 might be associated and plays essential role in GC progression.     

MicroRNA-630 suppresses epithelial-to-mesenchymal transition by regulating FoxM1 in gastric cancer cells

In the present study, we investigated the functional role of microRNA (miR)-630 in epithelial-to-mesenchymal transition (EMT) of gastric cancer (GC) cells, as well as the regulatory mechanism. Cells of human GC cell line SGC 7901 were transfected with miR-630 mimic or miR-630 inhibitor. The transfection efficiency was confirmed by qRT-PCR. Cell migration and invasion were determined by Transwell assay. Protein expression of E-cadherin, vimentin, and Forkhead box protein M1 (FoxM1) was tested by Western blot. Moreover, the expression of FoxM1 was elevated or suppressed, and then the effects of miR-630 abnormal expression on EMT and properties of migration and invasion were examined again, as well as protein expression of Ras/phosphoinositide 3-kinase (PI3K)/AKT related factors. The results showed that (i) the EMT and properties of migration and invasion were statistically decreased by overexpression of miR-630 compared to the control group but markedly increased by suppression of miR-630. However, (ii) abnormal expression of FoxM1 reversed these effects in GC cells. Moreover, (iii) expression of GTP-Rac1, p-PI3K, and p-AKT was decreased by miR-630 overexpression but increased by FoxM1 overexpression. (iv) The decreased levels of GTP-Rac1, p-PI3K, and p-AKT induced by miR-630 overexpression were dramatically elevated by simultaneous overexpression of FoxM1. In conclusion, our results suggest that miR-630 might be a tumor suppressor in GC cells. MiR-630 suppresses EMT by regulating FoxM1 in GC cells, supposedly via inactivation of the Ras/PI3K/AKT pathway.     

miR-22 regulates C2C12 myoblast proliferation and differentiation by targeting TGFBR1

Recently, miR-22 was found to be differentially expressed in different skeletal muscle growth period, indicated that it might have function in skeletal muscle myogenesis. In this study, we found that the expression of miR-22 was the most in skeletal muscle and was gradually up-regulated during mouse myoblast cell (C2C12 myoblast cell line) differentiation. Overexpression of miR-22 repressed C2C12 myoblast proliferation and promoted myoblast differentiation into myotubes, whereas inhibition of miR-22 showed the opposite results. During myogenesis, we predicted and verified transforming growth factor beta receptor 1 (TGFBR1), a key receptor of the TGF-β/Smad signaling pathway, was a target gene of miR-22. Then, we found miR-22 could regulate the expression of TGFBR1 and down-regulate the Smad3 signaling pathway. Knockdown of TGFBR1 by siRNA suppressed the proliferation of C2C12 cells but induced its differentiation. Conversely, overexpression of TGFBR1 significantly promoted proliferation but inhibited differentiation of the myoblast. Additionally, when C2C12 cells were treated with different concentrations of transforming growth factor beta 1 (TGF-β1), the level of miR-22 in C2C12 cells was reduced. The TGFBR1 protein level was significantly elevated in C2C12 cells treated with TGF-β1. Moreover, miR-22 was able to inhibit TGF-β1-induced TGFBR1 expression in C2C12 cells. Altogether, we demonstrated that TGF-β1 inhibited miR-22 expression in C2C12 cells and miR-22 regulated C2C12 cell myogenesis by targeting TGFBR1.     

miR-154 suppresses colorectal cancer cell growth and motility by targeting TLR2

MicroRNAs play critical roles in the development and progression of colorectal cancer (CRC). miR-154 acts as a tumor suppressor in several tumors; however, its role in CRC is poorly understood. Herein, we found that miR-154 was decreased in CRC tissues and cell lines. Ectopic expression of miR-154 remarkably suppressed cell proliferation and colony formation, migration and invasion in CRC cells. The toll-like receptor 2 (TLR2) was found to be a direct target of miR-154 in CRC cells. Inhibition of TLR2 performed similar effects with miR-154 overexpression on CRC cells, and overexpression of TLR2 could significantly reverse the tumor suppressive effects of miR-154 on CRC cells. This study suggests an essential role for miR-154 in CRC.     

miR-505 acts as a tumor suppressor in gastric cancer progression through targeting HMGB1

Gastric cancer (GC) is a frequent type of malignant tumor worldwide. GC metastasis results in the majority of clinical treatment failures. MicroRNAs (miRNA) are identified to exhibit crucial roles in GC. Our current study aimed to explore the biological roles of miR-505 in GC progression. It was observed that miR-505 was robustly decreased in GC cells compared with human normal gastric epithelial GES-1 cells. Overexpression of miR-505 was able to repress GC progression in AGS and BGC-823 cells. In addition, high-mobility group box 1 (HMGB1) has been identified as a crucial oncogene in several cancer types. By carrying out bioinformatics analysis, HMGB1 was predicted as a direct target of miR-505. Meanwhile, HMGB1 was found to be significantly increased in GC cells and it was confirmed in our study that miR-505 can directly target HMGB1 in vitro. miR-505 mimics can inhibit HMGB1 messenger RNA and protein expression dramatically. Subsequently, knockdown of HMGB1 can inhibit GC cell proliferation, colony formation, and induce cell apoptosis. Furthermore, HMGB1 silence suppressed GC cell migration and invasion greatly in vitro. Finally, it was validated that miR-505 can inhibit GC progression by targeting HMGB1 in vivo. Taken these together, it was indicated that miR-505/HMGB1 axis was involved in the development of GC. miR-505 can serve as a potential prognostic indicator in GC therapy.     

MiR-4756 promotes albumin-induced renal tubular epithelial cell epithelial-to-mesenchymal transition and endoplasmic reticulum stress via targeting Sestrin2

Accumulating evidence indicates that proteinuria promotes the progression of diabetic kidney disease (DKD) and induces renal epithelial tubular cell epithelial-to-mesenchymal transition (EMT) and endoplasmic reticulum (ER) stress, but the mechanism remains unclear. In our previous research, we found that miR-4756 levels were increased in the urinary extracellular vesicles of type 2 diabetes mellitus patients with macroalbuminuria. In a preliminary study, we found that miR-4756 may be derived from renal tubular epithelial cells, but its role has not been elucidated. Albumin stimulation significantly increased miR-4756 levels in HK-2 cells. In addition, an miR-4756 mimic accelerated albumin-stimulated HK-2 cell EMT and ER stress, and an miR-4756 inhibitor suppressed these events. We then found that miR-4756 targeted the 3′-untranslated region (UTR) of Sestrin2 and directly suppressed Sestrin2 expression. Furthermore, the induction of EMT and ER stress by the overexpression of miR-4756 was abolished by Sestrin2 overexpression. Moreover, the overexpression of miR-4756 increased ERK1/2 activation and decreased 5′ monophosphate-activated protein kinase activation. Thus, our study provides evidence that miR-4756 accelerates the process of DKD through Sestrin2, suggesting that targeting miR-4756 may be a novel strategy for DKD treatment.     

Long noncoding RNA ZEB1-AS1 attenuates ferroptosis of gastric cancer cells through modulating miR-429/BGN axis

Gastric cancer (GC) is the fifth utmost common malignant cancer type globally, in which ferroptosis acts a critical function in the progress of GC. Long noncoding RNA ZEB1-AS1 has been recognized in numerous cancers, but the role of ZEB1-AS1 in ferroptosis remains obscure. Hence, we investigated the efficacy of ZEB1-AS1 on ferroptosis of GC cells. The cell growth and viability were analyzed via cell counting kit assay and xenograft tumor model in vivo and in vitro, respectively. The RNA and protein expression were measured by qRT-PCR and western blot analysis assay, respectively. The levels of Fe²⁺, malondialdehyde (MDA), and lipid reactive oxygen species (ROS) were tested to determine ferroptosis. The erastin and RSL3 were used to induce ferroptosis. The mechanism was analyzed via luciferase reporter gene and RIP assays. The treatment of ferroptosis inducer Erastin and RSL3 suppressed the viability of GC cells and the ZEB1-AS1 overexpression rescued the phenotype in the cells. The levels of Fe²⁺, MDA, and ROS were enhanced through the depletion of ZEB1-AS1 in Erastin/RSL3 treated GC cells. ZEB1-AS1 directly sponged miR-429 in GC cells and miR-429 targeted BGN in GC cells, and the inhibition of miR-429 rescued ZEB1-AS1 depletion-inhibited BGN expression. We validated that miR-429 induced and BGN-repressed ferroptosis in cancer cells. The BGN overexpression and miR-429 suppression could reverse the efficacy of ZEB1-AS1 on proliferation and ferroptosis in cancer cells. The expression of ZEB1-AS1 and BGN was enhanced and miR-429 expression was decreased in clinical GC tissues. ZEB1-AS1 attenuated ferroptosis of cancer cells by modulating miR-429/BGN axis.     

miR-26a Suppresses Tumor Growth and Metastasis by Targeting FGF9 in Gastric Cancer

The role of miR-26a in cancer cells seemed controversial in previous studies. Until now, the role of miR-26a in gastric cancer remains undefined. In this study, we found that miR-26a was strongly downregulated in gastric cancer (GC) tissues and cell lines, and its expression levels were associated with lymph node metastasis and clinical stage, as well as overall survival and replase-free survival of GC. We also found that ectopic expression of miR-26a inhibited GC cell proliferation and GC metastasis in vitro and in vivo. We further identified a novel mechanism of miR-26a to suppress GC growth and metastasis. FGF9 was proved to be a direct target of miR-26a, using luciferase assay and western blot. FGF9 overexpression in miR-26a-expressing cells could rescue invasion and growth defects of miR-26a. In addition, miR-26a expression inversely correlated with FGF9 protein levels in GC. Taken together, our data suggest that miR-26a functions as a tumor suppressor in GC development and progression, and holds promise as a prognostic biomarker and potential therapeutic target for GC.     

Circular RNA hsa_circ_0110389 promotes gastric cancer progression through upregulating SORT1 via sponging miR-127-5p and miR-136-5p

Increasing studies have found that circular RNAs (circRNAs) are aberrantly expressed and play important roles in the occurrence and development of human cancers. However, the function of circRNAs on environmental carcinogen-induced gastric cancer (GC) progression remains poorly elucidated. In the present study, hsa_circ_0110389 was identified as a novel upregulated circRNA in malignant-transformed GC cells through RNA-seq, and subsequent quantitative real-time PCR verified that hsa_circ_0110389 was significantly increased in GC tissues and cells. High hsa_circ_0110389 expression associates with advanced stages of GC and predicts poor prognosis. Knockdown and overexpression assays demonstrated that hsa_circ_0110389 regulates proliferation, migration, and invasion of GC cells in vitro. In addition, hsa_circ_0110389 was identified to sponge both miR-127-5p and miR-136-5p and SORT1 was validated as a direct target of miR-127-5p and miR-136-5p through multiple mechanism assays; moreover, hsa_circ_0110389 sponged miR-127-5p/miR-136-5p to upregulate SORT1 expression and hsa_circ_0110389 promoted GC progression through the miR-127-5p/miR-136-5p–SORT1 pathway. Finally, hsa_circ_0110389 knockdown suppressed GC growth in vivo. Taken together, our findings firstly identify the role of hsa_circ_0110389 in GC progression, which is through miR-127-5p/miR-136-5p–SORT1 pathway, and our study provides novel insight for the identification of diagnostic/prognostic biomarkers and therapeutic targets for GC.Subject terms: Gastrointestinal cancer, Non-coding RNAs     

Retracted: Downregulation of microRNA-1469 promotes the development of breast cancer via targeting HOXA1 and activating PTEN/PI3K/AKT and Wnt/β-catenin pathways

Breast cancer (BC) is a common malignancy which is the most frequently diagnosed cancer in women all over the worldwide. This study aimed to investigate the roles of miR-1469 in the development of BC, as well as its regulatory mechanism. The expression levels of miR-1469 in BC tissues, serum, and cell lines were determined. Effects of overexpression of miR-1469 on MCF7 cell viability, colony-forming ability, apoptosis, migration, and invasion were then investigated. Furthermore, the potential target of miR-1469 in MCF7 cells was explored. Besides, the association between miR-1469, PTEN/PI3K/AKT, and Wnt/β-catenin pathways was elucidated. Notably, confirmatory experiments by downregulation of miR-1469 in SK-BR-3 cells were further performed. The miR-1469 expression was significantly downregulated in BC tissues, serum, and cell lines. The overexpression of miR-1469 significantly inhibited the proliferation, arrested cell-cycle at G2/M phase, increased apoptosis, suppressed migration, and invasion of MCF-7 cells. In addition, HOXA1 was verified as a direct target of miR-1469, and the effects of overexpression of miR-1469 on the malignant behaviors of MCF7 cells were significantly counteracted by overexpression of HOXA1 concurrently. Furthermore, the overexpression of miR-1469 suppressed the activation of PTEN/PI3K/AKT and Wnt/β-catenin pathways, which was reversed overexpression of HOXA1 concurrently. Besides, confirmatory experiments showed that the inhibition of miR-1469 promoted the malignant behaviors of SK-BR-3 cells, which was inversed after miR-1469 inhibition and HOXA1 knockdown at the same time. Our findings reveal that downregulation of miR-1469 may promote the development of BC by targeting HOXA1 and activating PTEN/PI3K/AKT and Wnt/β-catenin pathways. MiR-1469 may serve as a promising target for BC therapy.     

miRNA-205 suppresses melanoma cell proliferation and induces senescence via regulation of E2F1 protein

MicroRNAs (miRNAs) regulate gene expression by repressing translation or directing sequence-specific degradation of complementary mRNA. Here, we report that expression of miR-205 is significantly suppressed in melanoma specimens when compared with nevi and is correlated inversely with melanoma progression. miRNA target databases predicted E2F1 and E2F5 as putative targets. The expression levels of E2F1 and E2F5 were correlated inversely with that of miR-205 in melanoma cell lines. miR-205 significantly suppressed the luciferase activity of reporter plasmids containing the 3'-UTR sequences complementary to either E2F1 or E2F5. Overexpression of miR-205 in melanoma cells reduced E2F1 and E2F5 protein levels. The proliferative capacity of melanoma cells was suppressed by miR-205 and mediated by E2F-regulated AKT phosphorylation. miR-205 overexpression resulted in induction of apoptosis, as evidenced by increased cleaved caspase-3, poly-(ADP-ribose) polymerase, and cytochrome c release. Stable overexpression of miR-205 suppressed melanoma cell proliferation, colony formation, and tumor cell growth in vivo and induced a senescence phenotype accompanied by elevated expression of p16INK4A and other markers for senescence. E2F1 overexpression in miR-205-expressing cells partially reversed the effects on melanoma cell growth and senescence. These results demonstrate a novel role for miR-205 as a tumor suppressor in melanoma.     

miR-25 promotes gastric cancer cells growth and motility by targeting RECK

Gastric cancer (GC) is the second leading cause of cancer-related death worldwide. Recently, accumulating evidence suggests that microRNAs (miRNAs) play prominent roles in tumorigenesis and metastasis. Here, we confirmed that miR-25 was significantly increased in human GC tissues and cell lines. Forced expression of miR-25 remarkably enhanced cell proliferation, migration, and invasion in GC cells, whereas inhibition of miR-25 by inhibitor caused significant suppression of proliferation and significant increase of apoptosis. Moreover, inhibition of miR-25 significantly decreased migration and invasion of GC cells. Finally, reversion-inducing-cysteine-rich protein with kazal motifs (RECK) was found to be a target of miR-25. Overexpression of RECK could significantly reverse the oncogenic effect of miR-25. Taken together, miR-25 might promote GC cells growth and motility partially by targeting RECK.     

Increased microRNA-223 in Helicobacter pylori-associated gastric cancer contributed to cancer cell proliferation and migration

Dysregulation of microRNA-223 (miR-223) was associated with gastric cancer (GC), in which Helicobacter pylori (H. pylori) played important roles. However, the mechanism of relationships between miR-223 and H. pylori-associated GC was largely undiscovered. Here, we found the overexpression of miR-223 was related with H. pylori positive infection in vivo and in vitro in GC by relative quantification of qRT-PCR. Upregulated miR-223 was responsible for the poorer prognosis of GC with H. pylori positive, also. The result indicated not only overexpression of miR-223 stimulated the proliferation by CCK-8 assays and colony formation of H. pylori associated GC cells, but also migration and invasion by scratch assay and transwell invasion assays in vitro. Above all, all our data declared H. pylori infection played an important role in developing GC according to overexpression of miR-223, which increased cancer cell proliferation and migration.