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Background: The cellular retinol binding protein I gene (CRBP) is downregulated in a subset of human breast cancers and in MMTV-Myc induced mouse mammary tumors. Functional studies suggest that CRBP downregulation contributes to breast tumor progression. What is the mechanism underlying CRBP downregulation in cancer? Here we investigated the hypothesis that CRBP is epigenetically silenced through DNA hypermethylation in human and mouse breast cancer. Results: Bisulfite sequencing of CRBP in a panel of 6 human breast cancer cell lines demonstrated that, as a rule, CRBP hypermethylation is closely and inversely related to CRBP expression and identified one exception to this rule. Treatment with 5-azacytidine, a DNA methyltransferase inhibitor, led to CRBP reexpression, supporting the hypothesis that CRBP hypermethylation is a proximal cause of CRBP silencing. In some cells CRBP reexpression was potentiated by co-treatment with retinoic acid, an inducer of CRBP, and trichostatin A, a histone deacetylase inhibitor. Southern blot analysis of a small panel of human breast cancer specimens identified one case characterized by extensive CRBP hypermethylation, in association with undetectable CRBP mRNA and protein. Bisulfite sequencing of CRBP in MMTV-Myc and MMTV-Neu/NT mammary tumor cell lines extended the rule of CRBP hypermethylation and silencing (both seen in MMTV-Myc but not MMTV-Neu/NT cells) from human to mouse breast cancer and suggested that CRBP hypermethylation is an oncogene-specific event. Conclusion: CRBP hypermethylation appears to be an evolutionarily conserved and principal mechanism of CRBP silencing in breast cancer. Based on the analysis of transgenic mouse mammary tumor cells, we hypothesize that CRBP silencing in human breast cancer may be associated with a specific oncogenic signature. [ABSTRACT FROM AUTHOR]

We investigated the mechanism of retinoic acid receptor (RAR) β2 gene silencing in breast cancer cells. Transfection experiments indicated that MCF-7 cells transactivate an exogenous β2 promoter (-1470/+156) to the same extent as MTSV1.7 breast epithelial cells, which express endogenous RARβ2. This was true even in the context of replicated chromatin, suggesting a cis-acting rather than a trans-acting defect. Cytosine methylation, a cis-acting DNA modification, has been implicated in RARβ2 silencing in cancer cells. Upon bisulfite genomic sequencing, we found that 3 CpG sites in the β2 RARE region were variably methylated in MCF-7 cells but were not methylated in MTSV1.7 cells or in 2 MDA-MB-231 subclones that differed in RARβ2 expression (high in clone A2, low in clone A4). However, the 5′-UTR region was hypermethylated in clone A4 relative to clone A2 cells. Following 5-azacytidine treatment, RA and trichostatin A markedly induced RARβ2 expression in MCF-7 cells but not in MDA-MB-231 clone A4 cells. A β2 RARE reporter construct in which the methylation-susceptible cytosines in the sense strand were replaced by thymine displayed marked loss of activity in a replicated chromatin-dependent manner. We conclude that cytosine methylation contributes to RARβ2 gene silencing in MCF-7 cells and that methylation of the RARE region may be particularly important. Oncogene (2000) 19, 4066–4070 [ABSTRACT FROM AUTHOR]

Background: Von Willebrand Disease (VWD) is a common inherited bleeding disorder. Patients with VWD suffering from severe bleeding may benefit from the use of secondary long‐term prophylaxis. Aim: Systematically summarize the evidence on the clinical outcomes of secondary long‐term prophylaxis in patients with VWD and severe recurrent bleedings. Methods: We searched Medline and EMBASE through October 2019 for relevant randomized clinical trials (RCTs) and comparative observational studies (OS) assessing the effects of secondary long‐term prophylaxis in patients with VWD. We used Cochrane Risk of Bias (RoB) tool and the RoB for Non‐Randomized Studies of interventions (ROBINS‐I) tool to assess the quality of the included studies. We conducted random‐effects meta‐analyses and assessed the certainty of the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Results: We included 12 studies. Evidence from one placebo controlled RCT suggested that VWD prophylaxis as compared to no prophylaxis reduced the rate of bleeding episodes (Rate ratio [RR],.24; 95% confidence interval [CI],.17–.35; low certainty evidence), and of epistaxis (RR,.38; 95%CI,.21–.67; moderate certainty evidence), and may increase serious adverse events RR 2.73 (95%CI.12–59.57; low certainty). Evidence from four before‐and‐after studies in which researchers reported comparative data suggested that VWD prophylaxis reduced the rate of bleeding (RR.34; 95%CI,.25–.46; very low certainty evidence). Conclusion: VWD prophylaxis treatment seems to reduce the risk of spontaneous bleeding, epistaxis, and hospitalizations. More RCTs should be conducted to increase the certainty in these benefits. [ABSTRACT FROM AUTHOR]

Introduction: von Willebrand disease (VWD) is an inherited bleeding disorder caused by a quantitative or qualitative dysfunction of von Willebrand factor. Clinicians, patients and other stakeholders have many questions about the diagnosis and management of the disease. Aim: To identify topics of highest importance to stakeholders that could be addressed by guidelines to be developed by the American Society of Hematology (ASH), the International Society on Thrombosis and Haemostasis (ISTH), the National Hemophilia Foundation (NHF) and the World Federation of Hemophilia (WFH). Methods: A survey to determine and prioritize topics to be addressed in the collaborative development of guidelines for VWD was distributed to international stakeholders including patients, caregivers and healthcare providers (HCPs). Representatives of the four organizations coordinated the distribution strategy. The survey focused on both diagnosis and management of VWD, soliciting 7‐point Likert‐scale responses and open‐ended comments, in English, French and Spanish. We conducted descriptive analysis with comparison of results by stakeholder type, gender and countries' income classification for the rating questions and qualitative conventional content data analysis for the open‐ended responses. Results: A total of 601 participants responded to the survey (49% patients/caregivers and 51% healthcare providers). The highest priority topics identified were diagnostic criteria/classification, bleeding assessment tools and treatment options for women and surgical patients. In contrast, screening for anaemia and differentiating plasma‐derived therapy versus recombinant therapies received lower ratings. Conclusion: This survey highlighted areas of importance to a diverse representation of stakeholders in the diagnosis and management of VWD, providing a framework for future guideline development and implementation. [ABSTRACT FROM AUTHOR]