Explore the vast range of titles available.

Background: MicroRNAs (miRNAs) regulate expression of many cancer-related genes through posttranscriptional repression of their mRNAs. In this study we investigate the proto-oncogene MYCN as a target for miRNA regulation. Methods: A luciferase reporter assay was used to investigate software-predicted miRNA target sites in the 3′-untranslated region (3′UTR) of MYCN . The miRNAs were overexpressed in cell lines by transfection of miRNA mimics or miRNA-expressing plasmids. Mutation of the target sites was used to validate MYCN 3′UTR as a direct target of several miRNAs. To measure miRNA-mediated suppression of endogenous N-myc protein, inhibition of proliferation and inhibition of clonogenic growth, miRNAs were overexpressed in a MYCN -amplified neuroblastoma cell line. Results: The results from this study show that MYCN is targeted by several miRNAs. In addition to the previously shown mir-34a/c , we experimentally validate mir-449 , mir-19a/b , mir-29a/b/c, mir-101 and let-7e/mir-202 as direct MYCN -targeting miRNAs. These miRNAs were able to suppress endogenous N-myc protein in a MYCN -amplified neuroblastoma cell line. The let-7e and mir-202 were strong negative regulators of MYCN expression. The mir-101 and the let-7 family miRNAs let-7e and mir-202 inhibited proliferation and clonogenic growth when overexpressed in Kelly cells. Conclusion: The tumour-suppressor miRNAs let-7 and mir-101 target MYCN and inhibit proliferation and clonogenic growth of MYCN -amplified neuroblastoma cells.

BackgroundNeuroblastoma is a neoplasm of the sympathetic nervous system representing the most frequently diagnosed solid tumour in infants. Despite continued improvements in cancer treatment, the overall survival of patients with high risk neuroblastoma is still only 40–50%. Irrespective of risk factors, neuroblastomas generally respond well to initial therapy. However, the majority of high risk patients relapse with tumours refractory to standard chemotherapeutic agents. Therefore, the understanding of biological and molecular aspects of drug resistance in neuroblastoma may provide new opportunities for therapy of aggressive neuroblastoma.Recent evidence has revealed a substantial role of microRNAs (miRNAs) in multidrug resistance in various cancer types. MicroRNAs are small (18–24 nucleotides) non-coding RNA molecules that regulate the expression of genes at the post-transcriptional level by either direct cleavage of target mRNAs or repression of translation. Several studies indicate that deviant expression of certain miRNAs correlate with poor clinical outcome in neuroblastoma. However, the role of miRNAs in neuroblastoma cell resistance to chemotherapeutic drugs is poorly understood.MethodsTo explore the role of miRNAs in the resistance of neuroblastoma cells to anticancer drugs, we generated miRNA cDNA libraries from six isogenic human neuroblastoma cell line pairs established from the same patients at the time of initial diagnosis and relapse following therapy. To analyse expression patterns of miRNAs, a deep sequencing analysis (SOLiD sequencing) was performed using the miRNA cDNA libraries.ResultsDeep sequencing analysis (SOLiD sequencing) revealed differential expression patterns of miRNAs before and after treatment. Systematic analysis of these miRNA expression patterns identified potential alterations in pathways associated with drug resistance suggesting that dysregulation of miRNAs might influence sensitivity to therapy.ConclusionWe anticipate that our findings will provide new insights into the molecular mechanisms of drug resistance in neuroblastoma.

Abnormal increases in nucleolar size and number caused by dysregulation of ribosome biogenesis has emerged as a hallmark in the majority of spontaneous cancers. The observed ribosome hyperactivity can be directly induced by the MYC transcription factors controlling the expression of RNA and protein components of the ribosome. Neuroblastoma, a highly malignant childhood tumor of the sympathetic nervous system, is frequently characterized by MYCN gene amplification and high expression of MYCN and c-MYC signature genes. Here, we show a strong correlation between high-risk disease, MYCN expression, poor survival, and ribosome biogenesis in neuroblastoma patients. Treatment of neuroblastoma cells with quarfloxin or CX-5461, two small molecule inhibitors of RNA polymerase I, suppressed MycN expression, induced DNA damage, and activated p53 followed by cell cycle arrest or apoptosis. CX-5461 repressed the growth of established MYCN -amplified neuroblastoma xenograft tumors in nude mice. These findings suggest that inhibition of ribosome biogenesis represent new therapeutic opportunities for children with high-risk neuroblastomas expressing high levels of Myc.

The MYCN oncogene is frequently amplified in neuroblastoma and is associated with aggressive disease and treatment failure. MYCN induces expression of different miRNAs, which are posttranscriptional regulators of gene expression with established roles in neuroblastoma development.In this study, we show that MYCN -amplified cell lines not only express miRNAs with functions inside the cell, but also secrete populations of miRNAs inside small vesicular structures called exosomes, with the ability to shuttle to other cells. We have isolated and characterised exosomes from MYCN amplified cell lines, and here demonstrate their ability to be taken up by other cells. By profiling the miRNA expression, we demonstrate high expression of a group of established on comirs in exosomes from two MYCN- amplified cell lines. Despite the fact that other studies have demonstrated the ability of exosomal miRNAs to regulate their targets in recipient cells, we did not observe this with exosomes from MYCN -amplified cells. However, exosomes were able to induce in vitro angiogenic tube formation, suggesting that they can have tumorigenic properties.These new findings reveal a potential new way for MYCN -amplified neuroblastoma cells to interact with their environment.

ObjectivesTo compare mortality risks in patients with rheumatoid arthritis-associated interstitial lung disease (RA-ILD) and patients with RA without ILD.DesignMatched cohort study.SettingThe study was conducted in Denmark, using nationwide, prospectively collected data.ParticipantsAmong patients with RA diagnosed between 2004 and 2016, 679 patients with RA-ILD were matched for birth year, gender and age at RA diagnosis with 11 722 patients with RA but without ILD.Main outcome measuresMortality risks were assessed using Kaplan-Meier mortality curves, and hazard rate ratios (HRRs) for death were estimated using Cox proportional hazards regression models.ResultsThe number of prevalent RA patients more than doubled from 15 352 to 35 362 individuals during the study period. RA-ILD was seen in 2.2% of incident RA patients. 34.0% of RA-ILD cases were diagnosed within 1 year prior to and 1 year after the RA diagnosis. One-year mortality was 13.9% (95% CI, 11.4% to 16.7%) in RA-ILD and 3.8% (95% CI, 3.5% to 4.2%) in non-ILD RA, 5-year mortality was 39.0% (34.4% to 43.5%) and 18.2% (17.3% to 19.1%) and 10-year mortality was 60.1% (52.9% to 66.5%) and 34.5% (32.8% to 36.1%), respectively. The HRRs for death were 2 to 10 times increased for RA-ILD compared with non-ILD RA, irrespective of follow-up period. Stratified analysis showed that the HRR for death was highest in the first months after the diagnosis of RA-ILD was made, especially in patients diagnosed with RA before diagnosis of ILD. HRR was higher in males and in patients without comorbidity as assessed by the Charlson Comorbidity Index.ConclusionsILD is a serious complication in RA, with a significantly increased mortality compared with a large matched cohort of RA comparisons without ILD.

A gap exists between guidelines and real-world clinical practice for the management and treatment of chronic obstructive pulmonary disease (COPD). Although this has narrowed in the last decade, there is room for improvement in detection rates, treatment choices and disease monitoring. In practical terms, primary care practitioners need to become aware of the huge impact of COPD on patients, have non-judgemental views of smoking and of COPD as a chronic disease, use a holistic consultation approach and actively motivate patients to adhere to treatment. This article is based on discussions at a virtual meeting of leading Nordic experts in COPD (the authors) who were developing an educational programme for COPD primary care in the Nordic region. The article aims to describe the diagnosis and lifelong management cycle of COPD, with a strong focus on providing a hands-on, practical approach for medical professionals to optimise patient outcomes in COPD primary care.

ObjectiveTo evaluate the impact of comorbidities, age and clinical presentation of TB on mortality among Danish patients with TB.MethodsDanish patients with an ICD-10 (International Statistical Classification of Diseases and Related Health Problems 10th Revision) diagnosis of TB in 1998–2010 were identified in the National Patient Registry and matched with controls (1:4) on age, gender, civil status and geography. Comorbid diagnoses up to 3 years before and after TB diagnosis or enrolment as control as well as survival data were obtained from national databasesResultsWe included 8433 cases and 33 707 controls. Respiratory diseases were the most common comorbidities among cases (12.4% of cases, 3.8% of controls (p<0.001)). Overall HR of death was 2.45 (2.31; 2.59). Relative mortality was especially increased among younger adults (HR 8.70 (95% CI 5.53 to 13.69) among the 30 to 39-year-olds). While overall mortality increased with Deyo-Charlson comorbidity (DCC) score, relative mortality among cases was highest in the low-DCC group. Additionally, male gender, low income and central nervous system TB were risk factors for death among TB cases. The most common cause of death in both groups was non-lung cancers, among TB cases followed by COPD, TB and lung cancer, all being significantly more common among TB cases.ConclusionIn Denmark, TB carries substantial mortality. Among those who die, 12% are reported to die from TB. A high relative mortality among younger adults underscores the importance of continually targeting high-risk TB groups in low-incidence countries.