Expression Levels Of miR-494 Research Articles

MicroRNA-494 regulates high glucose-induced cardiomyocyte apoptosis and autophagy by PI3K/AKT/mTOR signalling pathway.

Diabetic cardiomyopathy (DCM) is one of the major cardiovascular complications of diabetes. However, the mechanism of DCM is not fully understood. Studies have confirmed that certain microRNAs (miRNAs/miRs) are key regulators of DCM. The aim of this study was to investigate the role and mechanism of microRNA (miR)-494 in cardiomyocyte apoptosis and autophagy induced by high glucose (HG). By establishing a rat DCM model and an HG-treated H9c2 cells injury model, cardiac function was detected by echocardiography, myocardial tissue was stained by immunohistochemistry, and Cell Counting Kit-8 assay and lactate dehydrogenase assay were used to detect the cardiomyocyte injury. Cell apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labelling staining, and western blotting was used to detect death and autophagy. The results showed that the expression level of miR-494 was higher in the myocardial tissue of DCM rats and the myocardial cells of H9c2 treated with HG. Compared with the corresponding negative control groups, miR-494 mimics enhanced HG-induced apoptosis and autophagy, whereas miR-494 inhibitors showed the opposite effect, corresponding PI3K, AKT, and mTOR phosphorylation level has changed. These findings identify that miR-494 could regulate cell apoptosis and autophagy through PI3K/AKT/mTOR signalling pathway, participating in the regulation of cardiomyocyte cell damage after HG. These findings provide new insights for the further study of the molecular mechanism and treatment of DCM.

The regulating role of miR-494 on HCCR1 in cervical cancer cells.

This study focused on miR-494 inhibiting the proliferation, migration and invasion of cervical cancer cells by regulating HCCR1. During the study, 30 pairs of primary cervical cancer tissues and adjacent tissues diagnosed by pathology were collected, and then placed in a cryopreservation tube, immediately placed in liquid nitrogen to freeze, and then moved to a -80 °C refrigerator for storage until use. They were dipped with crystal violet staining solution for 20 minutes, washed 3 times with PBS, and dried at room temperature. The polycarbonate film on the chamber was gently cut, placed on a glass slide, and covered with neutral resin. The number of cells in 5 random fields was counted under a microscope, and the differences between the groups were compared. The qRT-PCR results showed that compared with the normal cervical tissue cell line HCCR1, the expression levels of miR-494 in cervical cancer cell lines HCCR1 and C-33A were significantly reduced. Compared with the transfection of mimics NC, the level of HCCR1mRNA and protein decreased significantly when transfected with miRNA-494mimics (P <0.05); compared with the transfection of inhibitor NC, the level of HCCR1 mRNA and protein increased significantly when transfected with miRNA-494 inhibitor (P <0.05).

MiR-494 Inhibits the Proliferation, Migration and Invasion of Cervical Cancer Cells by Regulating LETMD1.

LETMD1 is a differentially expressed gene selected by scientists from cervical cancer (CC) tissues by RT-PCR technology. It has been confirmed that LETMD1 is overexpressed in many human malignant tumors, so it can be used as an early diagnostic marker for malignant tumors and as a target for gene therapy. The purpose of this article is to further explore the effectiveness of miR-494 in inhibiting the proliferation, migration and invasion of CC cells by regulating LETMD1, selecting 40 cases of CC admitted to a hospital from June 2015 to September 2018 Patients, tumor tissue specimens were taken from the primary tumor tissue of CC, and normal tissues near the cutting edge were collected as controls. Normal tissues were confirmed by pathology after surgery that they were not invaded by cancer tissues. The results of the study showed that the expression level of miR-494 increased by 15%, and the prognostic survival rate after surgery increased by 20%, depending on gender, age, tumor size, and tumor site. After high expression of miR-494 in CC patients, the vascular invasion of CC cells was reduced by 33%, and distant metastasis was reduced by 11%, and the survival time of patients was significantly prolonged. After the expression of LETMD1, the proportion of cancer cells decreased by 5%, the proportion of macrophages increased by 2%, and the dendritic cells increased by 3%.

Gene expression of one important microRNA in blood and tissue samples of oral squamous cell carcinoma

Introduction: Oral Squamous Cell Carcinoma (OSCC) is one of the most common oral malignancies, which accounts for 80-90% of malignant neoplasms of the oral cavity. MicroRNAs (miRNAs) are small RNA molecules that regulate post-transcriptional gene expression by targeting mRNAs. Materials and Methods: In this case-control study, 40 patients with oral squamous cell carcinoma and 40 healthy individuals as control were studied. Blood samples were collected from both groups. Also, 30 cancer tissue samples and 30 healthy tissue samples were prepared and evaluated. RNA was extracted from collected peripheral blood and tissue samples and evaluated for the expression level of miR-494 via real-time PCR technique. P. value values&lt;0.05 were considered statistically significant. Results: The expression level of miR-494 in serum (peripheral blood) of patients with oral squa- mous cell carcinoma increased by 1.12 fold (P-value&lt;0.001) compared with healthy individuals. Also, the expression level of miR-494 in samples of oral squamous cell carcinoma infected tissue showed a 1.28-fold increase compared to healthy tissue. Conclusion: The results of this study indicate an increase in the expression level (up-regula- tion) of miR-494 in oral squamous cell carcinoma. This biomarker can be used in screening and early detection of oral squamous cell carcinoma.

Increased Expression of miR-494 in Serum of Patients with Prostate Cancer and its Potential Diagnostic Value.

Prostate cancer is a common male cancer with poor prognosis, and to find molecular diagnostic markers for the early diagnosis of prostate cancer is urgently needed. The aim of this study is to investigate the diagnostic value of serum expression level of miR-494 for prostate cancer. Ninety patients with prostate cancer and 90 patients with benign prostatic hyperplasia were enrolled in this study, and 90 healthy volunteers served as the control group. The serum of the participants was collected, and the expression level of miR-494 was measured by RT-PCR. Then the relationship between the expression of miR-494 and the clinical characteristics of the patients was analyzed. Moreover, the correlation between the expression of miR-494 and the Gleason score as well as serum level of prostate specific antigen (PSA) were analyzed. Finally, the diagnostic value of miR-494 for the early diagnosis of prostate cancer was analyzed by ROC curve. miR-494 was significantly increased in the prostatic hyperplasia group compared with the control group, and the level of miR-494 in the prostate cancer group was significantly higher than that in the prostatic hyperplasia group. The level of miR-494 in patients with prostate cancer was positively correlated with tumor size and tumor stage. Moreover, the level of miR-494 was positively correlated with the Gleason score (r = 0.3371, p = 0.0012) and serum level of PSA (r = 0.3485, p = 0.0008) in patients with prostate cancer. Finally, AUC of miR-494 was 0.8090 (95% confidence interval 0.7343 to 0.8837), suggesting that miR-494 is a sensitive biomarker for the diagnosis of prostate cancer. miR-494 was upregulated in the serum of the patients with prostate cancer and circulating miR-494 can be used as a biomarker for the early diagnosis of prostate cancer.

Roles of miR-494 in Intervertebral Disk Degeneration and the Related Mechanism

In this study, we focused on the regulatory roles of miR-494 in the pathogenesis of intervertebral disk degeneration (IDD) and the related mechanism. First, rat IDD models were established, and the expression levels of miR-494 in IDDs of the rats were examined. Next, human nucleus pulposus (NP) cells were cultured and transfected with miR-494 mimics and inhibitors, and the roles of miR-494 on the proliferation and apoptosis of cells were determined using MTT cell proliferation assay and flow cytometry methods. Furthermore, the targeting relationship between miR-494 and neuro-oncological ventral antigen 1 (NOVA1) was examined by dual luciferase reporter assay. Finally, the expression of NOVA1, Caspase-3, Bcl-2-associated X protein (BAX), and B-cell lymphoma-2 (BCL-2) was examined using real-time quantitative polymerase chain reaction and western blot methods. The results demonstrated that the expression of miR-494 was significantly upregulated in IDD rats. Moreover, transfection of miR-494 inhibitors induced a significant increase in the proliferation and marked decrease in the apoptosis of the degenerated human NP cells. Transfection of miR-494 mimics has shown the opposite effects. Furthermore, NOVA1 has been confirmed as a target of miR-494, and the expressions of NOVA1 were significantly downregulated in IDD rats. In addition, transfection of miR-494 inhibitors significantly decreased the expression of Caspase-3 and BAX and markedly increased the expression of NOVA1 and BCL-2. Transfection of miR-494 mimics has shown the opposite effects. miR-494 was upregulated in IDD, and miR-494 might regulate the proliferation and apoptosis of NP cells through targeting NOVA1.

MiR-494 inhibits cervical cancer cell proliferation through upregulation of SOCS6 expression.

It is unclear how microRNA (miR)-494 inhibits the proliferation of cervical cancer cells by altering the expression of SOCS6. Therefore, the present study aimed to investigate the molecular mechanism underlying miR-494 regulation of suppressor of cytokine signaling 6 (SOCS6) in human cervical cancer samples and the human cervical cancer HeLa cell line. The expression of miR-494 was determined using reverse transcription-quantitative polymerase chain reaction. In addition, TargetScan was used to predict miR-494 target genes and the luciferase reporter assay was used to determine whether SOCS6 was a direct target of miR-494. The results of the present study demonstrated that compared with the cervical intraepithelial neoplasia and normal cervical tissues, the miR-494 expression level in cervical cancer samples was significantly decreased (P<0.01). In addition, compared with normal cervical tissue, miR-494 expression level was significantly decreased in cervical intraepithelial lesions (P<0.05). Furthermore, the expression of miR-494 was associated with patients with or without lymph node metastasis, clinical stage and depth of stromal invasion (P<0.01); however, miR-494 expression was not identified to be associated with age, tumor size and menopausal status (P>0.05). Transfection of a miR-494 mimic significantly increased the expression level of miR-494 in HeLa cells (P<0.01), and anti-miR-494 transfection decreased the expression of miR-494 (P<0.01). An MTT proliferation assay and Boyden chamber invasion ability assay revealed that miR-494 mimic transfection significantly inhibited the proliferation, and invasion ability of HeLa cells (P<0.01), whereas anti-miR-494 transfection significantly increased the proliferation and invasion ability (P<0.05). SOCS6 was predicted, using bioinformatics, to be the target gene of miR-494 and this was validated using a luciferase reporter assay. Western blot analysis revealed that transfection of miR-494 significantly increased the expression of SOCS6 in HeLa cells, and transfection of anti-miR-494 significantly decreased the expression of SOCS6. Therefore, the results of the present study demonstrated that miR-494 expression in cervical cancer was significantly decreased. Exhibiting a decreased expression level of miR-494 may result in enhanced proliferative and invasive abilities of HeLa cell, thus contributing to the occurrence, and development of cervical cancer.

MiR-494 protects pancreatic β-cell function by targeting PTEN in gestational diabetes mellitus.

Gestational diabetes mellitus (GDM) is one of the most common pregnancy complications characterized by insulin resistance and pancreatic β-cell dysfunction. Increasing evidence suggests that microRNAs (miRNAs) play key roles in the diverse types of diabetes, including GDM. However, the underlying mechanisms remain largely unknown. The purpose of this study is to investigate the role of microRNAs in GDM. The microarray data of dysregulated miRNAs in blood and placenta was retrieved in the GEO dataset under the accession number GSE19649. Quantitative reverse transcription PCR (qRT-PCR) was performed to analyze the expression levels of miR-494 in peripheral blood from twenty pairs of gestational diabetes (GDM) women and healthy women. Then, we investigated the effects of miR-494 on the insulin secretion of pancreatic β-cells. Moreover, the role of this miR-494 in regulating the proliferation and apoptosis of pancreatic β-cells were determined by MTT assay and flow cytometry, respectively in INS1 cells transfected with a miR-494 mimic or inhibitor. In addition, the direct target of miR-494 was confirmed using 3' untranslated region (UTR) luciferase reporter assay. Our data demonstrated that the miR-494 level was significantly decreased in the blood of GDM patients, and the low level was associated with a high concentration of blood glucose. Furthermore, overexpression of miR-494 improved pancreatic β-cell dysfunction by enhancing insulin secretion and total insulin content, inducing cell proliferation, and inhibiting cell apoptosis, whereas miR-494 knockdown exhibited decreased insulin secretion and proliferation, as well as stimulated apoptosis. In addition, phosphatase and tensin homolog (PTEN) which has been shown to play a pivotal role in apoptosis, was proved to be a direct target of miR-494 in pancreatic β-cells. More importantly, siRNA-induced downregulation of PTEN reversed the effects of miR-494 knockdown on insulin secretion, cell proliferation, and apoptosis of pancreatic β-cells.

MiR‐494 acts as an anti‐oncogene in gastric carcinoma by targeting c‐myc

We recently showed that miR-494 was downregulated in gastric carcinoma (GC). The objectives of this study were to determine the role of miR-494 in GC malignancy and to identify its target genes. Real-time polymerase chain reaction was employed to quantify the expression level of miR-494 and c-myc in gastric cancer tissues. Bioinformatics was used to predict the downstream target genes of miR-494, which were confirmed by luciferase and RNA immunoprecipitation assays. Cell functional analyses and a xenograft mouse model were used to evaluate the role of miR-494 in malignancy. miR-494 was downregulated in human GC tissues and in GC cells and was negatively correlated with c-myc expression. High level of c-myc or low level of miR-494 correlated with poor prognosis. The miR-494-binding site in the c-myc 3' untranslated region was predicted using TargetScan and was confirmed by the luciferase assay. Additionally, c-myc and miR-494 were enriched in coimmunoprecipitates with tagged Argonaute2 proteins in cells overexpressing miR-494. Furthermore, a miR-494 mimic significantly downregulated endogenous c-myc expression, which may contribute to the delayed G1/S transition, decreased synthesis phase bromodeoxyuridine incorporation, and impaired cell growth and colony formation; on the other hand, treatment with a miR-494 inhibitor displayed the opposite effects. Reduced tumor burden and decreased cell proliferation were observed following the delivery of miR-494 into xenograft mice. miR-494 is downregulated in human GC and acts as an anti-oncogene by targeting c-myc. miR-494 plays a role in the pathogenesis of gastric cancer in a recessive fashion.

MicroRNA-494 Downregulates KIT and Inhibits Gastrointestinal Stromal Tumor Cell Proliferation

Gain-of-function mutations and KIT overexpression are well-known tumorigenesis mechanisms in gastrointestinal stromal tumors (GIST). This study aimed to discover microRNAs (miRNA) that target KIT and reveal the relationship between the discovered miRNAs and KIT expression in GISTs. Fresh-frozen GISTs from 31 patients were used to confirm the relationship between miR-494 and KIT expression using quantitative reverse transcription-PCR to assess miR-494 expression levels and Western blotting to assess KIT protein expression levels. A luciferase assay was conducted for the target evaluation. The functional effects of miR-494 on GIST882 cells (GIST cell line with activating KIT mutation) were validated by a cell proliferation assay and fluoresce-activated cell sorting analysis. An inverse relationship was found between the expression levels of miR-494 and KIT in GISTs (r = -0.490, P = 0.005). The direct targeting of KIT by miR-494 was shown by the reduction in KIT expression after miR-494 overexpression and the increase in KIT expression after inhibiting endogenous miR-494 expression. We showed that miR-494 regulates KIT by binding two different seed match sites. Induced miR-494 overexpression in GIST882 reduced the expression of downstream molecules in KIT signaling transduction pathways, including phospho-AKT and phospho-STAT3. Finally, miR-494 overexpression provoked apoptosis and inhibited GIST cell growth, which were accompanied by changes in G(1) and S phase content. Our findings indicate that miR-494 is a negative regulator of KIT in GISTs and overexpressing miR-494 in GISTs may be a promising approach to GIST treatment.