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*

Humans ; Carcinogenesis/genetics* ; Gene Expression Regulation, Neoplastic ; Genes, cdc ; Nasopharyngeal Carcinoma/genetics* ; Nasopharyngeal Neoplasms/genetics* ; RNA Helicases/metabolism*

OBJECTIVE: To assess the value of m⁷G-lncRNAs in predicting the prognosis and microenvironment of colorectal cancer (CRC). METHODS: We screened m⁷G-lncRNAs from TCGA to construct an m⁷G-lncRNAs risk model using multivariate Cox analysis, which was validated using ROC and C-index curves. Calibration and nomogram were used to predict the prognosis of CRC patients. Point-bar charts and K-M survival curves were used to assess the correlation of risk scores with the patients' clinical staging and prognosis. CIBERSORT and ESTIMATE were used to explore the association between the tumor microenvironment and immune cell infiltration in patients in high and low risk groups and the correlation of risk scores with microsatellite instability, stem cell index and immune checkpoint expression. A protein-protein interaction network was constructed, and the key targets regulated by m⁷G-lncRNAs were identified and validated in paired samples of CRC and adjacent tissues by immunoblotting. RESULTS: We identified a total of 1722 m⁷G-lncRNAs from TCGA database, from which 12 lncRNAs were screened to construct the risk model. The AUCs of the risk model for predicting survival outcomes at 1, 3 and 5 years were 0.727, 0.747 and 0.794, respectively. The AUC of the nomogram for predicting prognosis was 0.794, and the predicted results were consistent with actual survival outcomes of the patients. The patients in the high-risk group showed more advanced tumor stages and a greater likelihood of high microsatellite instability than those in the low-risk group (P < 0.05). The tumor stemness index was negatively correlated with the risk score (r=-0.19; P=7.3e-05). Patients in the high-risk group had higher stromal cell scores (P=0.0028) and higher total scores (P=0.007) with lowered expressions of activated mast cells (r=-0.11; P=0.045) and resting CD4+ T cells (r=-0.14; P=0.01) and increased expressions of most immune checkpoints (P < 0.05). ATXN2 (P= 0.006) and G3BP1 (P=0.007) were identified as the key targets regulated by m⁷G-lncRNAs, and their expressions were both higher in CRC than in adjacent tissues. CONCLUSION The risk model based on 12 m⁷G-lncRNAs has important prognostic value for CRC and can reflect the microenvironment and the efficacy of immunotherapy in the patients.
Biomarkers, Tumor/metabolism* ; Colonic Neoplasms ; DNA Helicases/metabolism* ; Gene Expression Regulation, Neoplastic ; Humans ; Microsatellite Instability ; Poly-ADP-Ribose Binding Proteins/metabolism* ; Prognosis ; RNA Helicases/metabolism* ; RNA Recognition Motif Proteins/metabolism* ; RNA, Long Noncoding/metabolism* ; Tumor Microenvironment

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

Up-frameshift 1 (UPF1), as the most critical factor in nonsense-mediated messenger RNA (mRNA) decay (NMD), regulates tumor-associated molecular pathways in many cancers. However, the role of UPF1 in lung adenocarcinoma (LUAD) amino acid metabolism remains largely unknown. In this study, we found that UPF1 was significantly correlated with a portion of amino acid metabolic pathways in LUAD by integrating bioinformatics and metabolomics. We further confirmed that UPF1 knockdown inhibited activating transcription factor 4 (ATF4) and Ser51 phosphorylation of eukaryotic translation initiation factor 2α (eIF2α), the core proteins in amino acid metabolism reprogramming. In addition, UPF1 promotes cell proliferation by increasing the amino-acid levels of LUAD cells, which depends on the function of ATF4. Clinically, UPF1 mRNA expression is abnormal in LUAD tissues, and higher expression of UPF1 and ATF4 was significantly correlated with poor overall survival (OS) in LUAD patients. Our findings reveal that UPF1 is a potential regulator of tumor-associated amino acid metabolism and may be a therapeutic target for LUAD.
Activating Transcription Factor 4/genetics* ; Adenocarcinoma of Lung ; Amino Acids ; Cell Proliferation ; Eukaryotic Initiation Factor-2 ; Humans ; Lung Neoplasms ; RNA Helicases/metabolism* ; RNA, Messenger/metabolism* ; Trans-Activators/metabolism*

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

Antiviral Agents ; chemistry ; metabolism ; Crystallography, X-Ray ; Ligands ; Protein Binding ; Protein Structure, Tertiary ; RNA Helicases ; chemistry ; classification ; metabolism ; Static Electricity ; Viral Proteins ; chemistry ; classification ; metabolism ; Zika Virus ; enzymology

The elucidation of the molecular mechanisms underlying the differentiation and proliferation of human adipose tissue-derived stromal cells (hADSCs) represents a critical step in the development of hADSCs-based cellular therapies. To examine the role of the microRNA-103a-3p (miR-103a-3p) in hADSCs functions, miR-103a-3p mimics were transfected into hADSCs in order to overexpress miR-103a-3p. Osteogenic differentiation was induced for 14 days in an osetogenic differentiation medium and assessed by using an Alizarin Red S stain. The regulation of the expression of CDK6 (cyclin-dependent kinase 6), a predicted target of miR-103a-3p, was determined by western blot, real-time PCR and luciferase reporter assays. Overexpression of miR-103a-3p inhibited the proliferation and osteogenic differentiation of hADSCs. In addition, it downregulated protein and mRNA levels of predicted target of miR-103a-3p (CDK6 and DICER1). In contrast, inhibition of miR-103a-3p with 2'O methyl antisense RNA increased the proliferation and osteogenic differentiation of hADSCs. The luciferase reporter activity of the construct containing the miR-103a-3p target site within the CDK6 and DICER1 3'-untranslated regions was lower in miR-103a-3p-transfected hADSCs than in control miRNA-transfected hADSCs. RNA interference-mediated downregulation of CDK6 and DICER1 in hADSCs inhibited their proliferation and osteogenic differentiation. The results of the current study indicate that miR-103a-3p regulates the osteogenic differentiation of hADSCs and proliferation of hADSCs by direct targeting of CDK6 and DICER1 partly. These findings further elucidate the molecular mechanisms governing the differentiation and proliferation of hADSCs.
Adipose Tissue/*cytology ; Cell Differentiation ; *Cell Proliferation ; Cells, Cultured ; Cyclin-Dependent Kinase 6/genetics ; DEAD-box RNA Helicases/genetics ; *Gene Expression Regulation ; Humans ; MicroRNAs/genetics/*metabolism ; *Osteogenesis ; Ribonuclease III/genetics ; Stromal Cells/cytology/metabolism