OBJECTIVES: To investigate the mechanism of DDX17 for regulating proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) during the development of pulmonary hypertension (PH). METHODS: In murine PASMCs cultured under normoxic or hypoxic conditions, the effects of transfection with si-Ddx17 and insulin treatment, alone or in combination, on cell proliferation and migration were evaluated using Ki-67 immunofluorescence staining, scratch assay and Transwell assay. Western Blotting was performed to detect the changes in protein expression levels of DDX17, 4EBP1, S6, p-4EBP1, and p-S6. In a mouse model of PH induced by intraperitoneal injection of monocrotaline (MCT), the changes in pulmonary vasculature were examined using HE staining following tail vein injection of AD-Ddx17i. RESULTS: The PASMCs in hypoxic culture exhibited significantly enhanced cell proliferation and migration and protein expressions of p-4EBP1 and p-S6, and these changes were obviously reversed by transfection with si-Ddx17. Treatment with insulin significantly attenuated the effect of si-Ddx17 against hypoxic exposure-induced changes in PASMCs. In the mouse model of MCT-induced PH, transfection with AD-Ddx17i obviously alleviated pulmonary vascular stenosis and intimal hyperplasia. CONCLUSIONS The expression of DDX17 is elevated in hypoxia-induced PASMCs and PH mice, and silencing DDX17 significantly inhibits PASMC proliferation and migration in vitro and pulmonary vascular remodeling in PH mice by reducing mTORC1 activity.
Animals ; Cell Proliferation ; Cell Movement ; DEAD-box RNA Helicases/metabolism* ; Myocytes, Smooth Muscle/metabolism* ; Mice ; Pulmonary Artery/cytology* ; Hypertension, Pulmonary/metabolism* ; Mechanistic Target of Rapamycin Complex 1 ; Cells, Cultured ; Muscle, Smooth, Vascular/cytology*

OBJECTIVES: To investigate the regulatory mechanism of aurora kinase B (AURKB) for promoting malignant phenotype of osteosarcoma cells. METHODS: HA-Vector or HA-AURKB was transfected in 293T cells to identify the molecules interacting with AURKB using immunoprecipitation combined with liquid chromatography-tandem mass spectrometry followed by verification with co-immunoprecipitation and Western blotting. In cultured osteosarcoma cells with lentivirus-mediated RNA interference of AURKB or DHX9 or their overexpression, the changes in cell proliferation, migration, and invasion activities were observed with EDU and Transwell assays. Mechanistic analysis was performed using Co-IP and in vivo ubiquitination experiments to detect the interaction between AURKB and DHX9 and the phosphorylation and ubiquitination levels of DHX9. Western blotting was used to detect the effect of AURKB and DHX9 on activation of nuclear factor-κB (NF-κB) signaling. RESULTS: AURKB was highly expressed in osteosarcoma cell lines, and in osteosarcoma 143B cells, AURKB silencing significantly reduced cell proliferation, migration and invasion abilities. Interactions between AURKB and DHX9 were detected, and they were both highly expressed in osteosarcoma tissues; silencing AURKB reduced the protein expression of DHX9, and AURKB overexpression increased DHX9 phosphorylation. Silencing AURKB did not significantly affect the transcription and translation of DHX9 but accelerated its degradation and ubiquitination. Overexpression of DHX9 effectively reversed the effects of AURKB silencing on IKBα protein and phosphorylated p65, promoted nuclear translocation of p65 to activate the NF-κB signaling pathway, and enhanced the proliferation, migration, and invasion abilities of cultured osteosarcoma cells. CONCLUSIONS AURKB overexpression promotes the malignant phenotype of osteosarcoma cells by activating the NF-κB signaling pathway via regulating DHX9.
Humans ; Osteosarcoma/genetics* ; Cell Proliferation ; NF-kappa B/metabolism* ; Signal Transduction ; Cell Line, Tumor ; Cell Movement ; DEAD-box RNA Helicases/genetics* ; Aurora Kinase B/genetics* ; Phenotype ; Bone Neoplasms/genetics* ; Neoplasm Invasiveness ; Phosphorylation ; Neoplasm Proteins

We knocked out the retinoic acid-inducible gene I (RIG-I) in HEK293 cells via CRISPR/Cas9 to reveal the effects of RIG-I knockout on the key factors in the type I interferon signaling pathway. Three single guide RNAs (sgRNAs) targeting RIG-I were designed, and the recombination vectors were constructed on the basis of the pX459 vector and used to transfect HEK293 cells, which were screened by puromycin subsequently. Furthermore, a mimic of virus, poly I: C, was used to transfect the cells screened out. RIG-I knockout was checked by sequencing, real-time quantitative PCR, Western blotting, and immunofluorescence assay. Meanwhile, the expression levels of key factors of type I interferon signaling pathway such as melanoma differentiation-associated gene 5 (MDA5), interferonβ1 (IFNβ1), and nuclear factor-kappa B p65 [NF-κB(p65)], as well as cell viability, were determined. The results showed that two HEK293 cell lines (S1 and S3) with RIG-I knockout were obtained, which exhibited lower mRNA and protein levels of RIG-I than the wild type HEK293 cells (P < 0.05). The mRNA levels of MDA5 and IFNβ1 in S1 and S3 cells and the protein level of NF-κB(p65) in S3 cells were lower than those in the wild type (P < 0.05). More extranuclear NF-κB(p65) protein was detected in S1 cells than in the wild type after transfection with poly I: C. Plus, the wild-type and S1 cells transfected with poly I: C for 48 h showcased reduced viability (P < 0.05), while S3 cells did not display the reduction in cell viability. In summary, the present study obtained two HEK293 cell lines with RIG-I knockout via CRISPR/Cas9, which provided a stable cell model for exploring the mechanism of type I interferon signaling pathway.
Humans ; HEK293 Cells ; CRISPR-Cas Systems ; DEAD Box Protein 58/metabolism* ; Signal Transduction ; Receptors, Immunologic/metabolism* ; Gene Knockout Techniques ; Transfection ; DEAD-box RNA Helicases/metabolism* ; RNA, Guide, CRISPR-Cas Systems/genetics* ; Interferon-Induced Helicase, IFIH1/metabolism* ; Transcription Factor RelA/metabolism* ; Interferon-beta/metabolism*

A complete proteomics study characterizing active androgen receptor (AR) complexes in prostate cancer (PCa) cells identified a diversity of protein interactors with tumorigenic annotations, including known RNA splicing factors. Thus, we chose to further investigate the functional role of AR-mediated alternative RNA splicing in PCa disease progression. We selected two AR-interacting RNA splicing factors, Src associated in mitosis of 68 kDa (SAM68) and DEAD (Asp-Glu-Ala-Asp) box helicase 5 (DDX5) to examine their associative roles in AR-dependent alternative RNA splicing. To assess the true physiological role of AR in alternative RNA splicing, we assessed splicing profiles of LNCaP PCa cells using exon microarrays and correlated the results to PCa clinical datasets. As a result, we were able to highlight alternative splicing events of clinical significance. Initial use of exon-mini gene cassettes illustrated hormone-dependent AR-mediated exon-inclusion splicing events with SAM68 or exon-exclusion splicing events with DDX5 overexpression. The physiological significance in PCa was investigated through the application of clinical exon array analysis, where we identified exon-gene sets that were able to delineate aggressive disease progression profiles and predict patient disease-free outcomes independently of pathological clinical criteria. Using a clinical dataset with patients categorized as prostate cancer-specific death (PCSD), these exon gene sets further identified a select group of patients with extremely poor disease-free outcomes. Overall, these results strongly suggest a nonclassical role of AR in mediating robust alternative RNA splicing in PCa. Moreover, AR-mediated alternative spicing contributes to aggressive PCa progression, where we identified a new subtype of lethal PCa defined by AR-dependent alternative splicing.
Humans ; Male ; Alternative Splicing ; Cell Line, Tumor ; DEAD-box RNA Helicases/metabolism* ; Disease Progression ; Gene Expression Regulation, Neoplastic ; Prostatic Neoplasms/pathology* ; Receptors, Androgen/metabolism* ; RNA Splicing Factors/metabolism*

Myelodysplastic syndrome (MDS) are a heterogeneous group of hematological malignancies. Currently, in addition to demethylated chemotherapy and hematopoietic stem cell transplantation, MDS patient-derived mesenchymal stem cells (MDS-MSC) play an important role in understanding the pathogenesis of MDS and related therapeutic targets. For example, abnormal expression of DICER1 gene, abnormalities of PI3K/AKT and Wnt/β-catenin signaling pathways provide new therapeutic targets for MDS. In addition, MDS-MSC is also affected by abnormal microenvironment of the body, such as inflammatory factor S100A9, as well as hypercoagulation and iron overload. In this review, genes, signaling pathways, cytokines, hematopoietic microenvironment, and the effect of therapeutic drugs for MDS-MSC were briefly summarized.
Cytokines/metabolism* ; DEAD-box RNA Helicases/metabolism* ; Hematologic Neoplasms/metabolism* ; Humans ; Mesenchymal Stem Cells ; Myelodysplastic Syndromes/genetics* ; Phosphatidylinositol 3-Kinases/metabolism* ; Ribonuclease III/metabolism* ; Tumor Microenvironment

RNA helicases, the largest family of proteins that participate in RNA metabolism, stabilize the intracellular environment through various processes, such as translation and pre-RNA splicing. These proteins are also involved in some diseases, such as cancers and viral diseases. Autophagy, a self-digestive and cytoprotective trafficking process in which superfluous organelles and cellular garbage are degraded to stabilize the internal environment or maintain basic cellular survival, is associated with human diseases. Interestingly, similar to autophagy, RNA helicases play important roles in maintaining cellular homeostasis and are related to many types of diseases. According to recent studies, RNA helicases are closely related to autophagy, participate in regulating autophagy, or serve as a bridge between autophagy and other cellular activities that widely regulate some pathophysiological processes or the development and progression of diseases. Here, we summarize the most recent studies to understand how RNA helicases function as regulatory proteins and determine their association with autophagy in various diseases.
Animals ; Antiviral Agents/pharmacology* ; Autophagy ; Beclin-1/metabolism* ; Carcinogenesis ; Cell Survival ; DEAD Box Protein 58/metabolism* ; Disease Progression ; Gene Expression Regulation ; Homeostasis ; Humans ; Immune System/physiology* ; Neoplasms/metabolism* ; RNA Helicases/metabolism* ; RNA Splicing ; Receptors, Immunologic/metabolism*

OBJECTIVETo investigate the relationship between the expression of DDX39 protein and prognosis in colorectal cancer.

METHODSClinical data and paraffin specimens of postoperative tumor tissue from 824 patients with primary colorectal cancer who received first surgical treatment at the Department of Colorectal Surgery of Changhai Hospital of Navy Military Medical University from January 2010 to December 2011 were collected. Paraffin samples of paracancerous tissues of 38 patients were served as controls. At the same time, samples of normal rectal mucous membrane from 37 cases after procedure of prolapse and hemorrhoids, and samples of colorectal adenoma from 33 cases after endoscopic treatment were enrolled in this study. All the specimens were made as the tissue microarray, and the expression of DDX39 protein was detected by immunohistochemistry. The expression of DDX39 in the epithelium and stroma was evaluated with the average staining intensity (H-Score) and the number of positive cells. It was defined as high expression in the epithelium that the H-Score was greater than or equal to 200. It was defined as high expression in the stroma that the number of positive cells was greater than or equal to 50 in 200 times the field of vision. Relationship of different DDX39 expression levels with clinicopathological parameters and prognosis of colorectal cancer was analyzed.

RESULTSThe expression of DDX39 in colorectal cancer tissues was lower than that in normal tissues, paracancerous tissues and adenomatous tissues, whether it is in the epithelium or in the stroma [DDX39 expression in the epithelium: normal tissues 253.2±64.1, paracancerous tissues 238.8±79.2, adenomatous tissues 259.4±51.6, colorectal cancer tissues 194.2±76.5 (P=0.000, P=0.005, P=0.000, respectively); DDX39 expression in the stroma: normal tissues 110.1±64.8, paracancerous tissues 106.0±49.2, adenomatous tissues 108.5±79.1, colorectal cancer tissues 54.1±34.7(all P=0.000)]. Among the cases of colorectal cancer, there were 541 cases of high DDX39 expression and 283 cases of low DDX39 expression in the epithelium; there were 424 cases of high DDX39 expression of and 400 cases of low DDX39 expression in the stroma. The high DDX39 expression and low DDX39 expression in epithelial and stromal of colorectal cancer were related respectively with tumor location (P=0.006, P=0.016), degree of tumor differentiation (P=0.002, P=0.064), TNM stage (P=0.021, P=0.000), serum CEA level (P=0.003, P=0.005), serum CA199 level (P=0.040, P=0.005) and tumor recurrence and metastasis (P=0.000, P=0.000). All the colorectal cancer cases were followed up for (41.6±15.7) months after operation. The 5-year overall survival (OS) and disease-free survival (DFS) rates of the cases with epithelial low DDX39 expression were 84.1% and 61.5%, and both were significantly lower as compared to those with epithelial high DDX39 expression (95.4% and 88.2%, P=0.000, P=0.000). The 5-year OS and DFS rates of the stroma low DDX39 expression were 86.8% and 66.8%, and both were significantly lower as compared to those with stroma high DDX39 expression (96.1% and 90.6%, P=0.000, P=0.000). Cox multivariate analysis showed that tumor differentiation (OS:HR=0.252, 95%CI: 0.128 to 0.497, P=0.000; DFS:HR=0.266, 95%CI: 0.134 to 0.530, P=0.000), DDX39 expression level in epithelium (OS: HR =0.229, 95%CI: 0.138 to 0.382, P=0.000; DFS: HR =0.266, 95%CI: 0.158 to 0.446, P=0.000), and DDX39 expression level in stroma (OS: HR =0.331, 95%CI: 0.188 to 0.582, P=0.000; DFS:HR=0.326, 95%CI: 0.184 to 0.578, P=0.000) were independent influencing factors of overall or disease-free survival in patients with colorectal cancer.

CONCLUSIONThe low expression of DDX39 protein suggests poor prognosis and DDX39 is expected to be a new prognostic marker of colorectal cancer.

Biomarkers, Tumor ; metabolism ; Colonic Neoplasms ; Colorectal Neoplasms ; metabolism ; pathology ; DEAD-box RNA Helicases ; metabolism ; Disease-Free Survival ; Humans ; Neoplasm Recurrence, Local ; Neoplasm Staging ; Prognosis

Objective To investigate the effects of microRNA-18a (miR-18a) on migration and invasion of hepatocellular carcinoma (HCC) cells, and its possible mechanism associated with Dicer l.Methods HepG2 and HepG2.2.15 cells were transfected with miR-18a inhibitor using Lipofectamine. Cell invasion was evaluated by transwell invasion assay, and cell migration was detected by transwell migration and wound-healing assays. Moreover, luciferase reporter assay was used to identify whether Dicer expression was regulated by miR-18a. Real-time RT-PCR and western blot were performed to analyze Dicer 1 expression. In addition, a functional restoration assay was performed to investigate whether miR-18a promotes HCC cell migration and invasion by directly targeting Dicer 1.Results miR-18a inhibitor can suppress the migration and invasion of HCC cells. Furthermore, suppression of Dicer l expression by small interfering RNA essentially abolished the inhibition of cell migration and invasion induced by miR-18a inhibitor, restorating these activities to levels similar to the parental HCC cells. Interestingly, suppression of miR-18a in HCC cells resulted in enhanced expression of Dicer l. In addition, the results of a luciferase assay demonstrated targeted regulation of Dicer l by miR-18a.Conclusion Our findings suggest that miR-18a promotes migration and invasion of HCC cells by inhibiting Dicer l expression.
Carcinoma, Hepatocellular ; genetics ; metabolism ; pathology ; Cell Movement ; DEAD-box RNA Helicases ; genetics ; metabolism ; Hep G2 Cells ; Humans ; Liver Neoplasms ; genetics ; metabolism ; pathology ; MicroRNAs ; genetics ; metabolism ; Neoplasm Invasiveness ; Neoplasm Proteins ; genetics ; metabolism ; RNA, Neoplasm ; genetics ; metabolism ; Ribonuclease III ; genetics ; metabolism

OBJECTIVETo detect the expression of D-E-A-D-box polypeptide 41 (DDX41) in human dental pulp tissues and cells.

METHODSThe mRNA and protein expressions of DDX41 in human dental pulp cells were detected by RT-PCR and immunocytochemistry, and the expression of DDX41 in human dental pulp tissues was investigated by immunohistochemistry.

RESULTSStrong expressions of DDX41 mRNA and protein were detected in dental pulp cells. In dental pulp tissues, DDX41 was expressed in the cytoplasm and nucleus of odontoblasts.

CONCLUSIONDDX41/STING-dependent TBK1-IRF3-IFN-β signaling pathway may play a role in innate immune responses of the dental pulp to caries and pulpitis.

Cell Nucleus ; metabolism ; Cells, Cultured ; Cytoplasm ; metabolism ; DEAD-box RNA Helicases ; metabolism ; Dental Pulp ; metabolism ; Humans ; Immunohistochemistry ; Odontoblasts ; metabolism ; RNA, Messenger ; Signal Transduction

Previously, we reported the expression levels of specific microRNA machinery components, DGCR8 and AGO2, and their clinical association in patients with idiopathic sudden hearing loss (SSNHL). In the present study, we investigated the other important components of microRNA machinery and their association with clinical parameters in SSNHL patients. Fifty-seven patients diagnosed with SSNHL and fifty healthy volunteers were included in this study. We evaluated mRNA expression levels of Dicer and Drosha in whole blood of patients with SSNHL and the control group, using RT & real-time PCR analysis. The Dicer mRNA expression level was down-regulated in patients with SSNHL. However, the Drosha mRNA expression level was not significantly altered in patients with SSNHL. Neither the Dicer nor Drosha mRNA expression level was not associated with any clinical parameters, including age, sex, duration of initial treatment from onset (days), initial Pure tone average, Siegel's criteria, WBC, and Erythrocyte sedimentation rate. However, mRNA expression levels of Dicer and Drosha were positively correlated to each other in patients with SSNHL. In this study, we demonstrated for the first time that the Dicer mRNA expression level was down-regulated in patients with SSNHL, suggesting its important role in pathobiology of SSNHL development.
Acute Disease ; Adult ; Biomarkers ; DEAD-box RNA Helicases/*blood ; Down-Regulation ; Female ; Gene Expression Regulation ; Hearing Loss, Sensorineural/*blood ; Hearing Loss, Sudden/*blood ; Humans ; Male ; MicroRNAs/*metabolism ; Middle Aged ; Ribonuclease III/*blood/*metabolism ; Statistics as Topic