Cd79a (called mb-1 here) encodes the Ig-alpha signaling component of the B cell receptor. The early B cell-specific mb-1 promoter was hypermethylated at CpG dinucleotides in hematopoietic stem cells but became progressively unmethylated as B cell development proceeded. The transcription factor Pax5 activated endogenous mb-1 transcription in a plasmacytoma cell line, but could not when the promoter was methylated. In this context, early B cell factor (EBF), a transcription factor required for B lymphopoiesis, potentiated activation of mb-1 by Pax5. EBF and the basic helix-loop-helix transcription factor E47 each contributed to epigenetic modifications of the mb-1 promoter, including CpG demethylation and nucleosomal remodeling. EBF function was enhanced by interaction with the transcription factor Runx1. These data suggest a molecular basis for the hierarchical dependence of Pax5 function on EBF and E2A in B lymphocyte development.

Transcriptionally silent genes are maintained in inaccessible chromatin. Accessibility of these genes requires their modification by chromatin remodeling complexes (CRCs), which are recruited to promoters by sequence-specific DNA-binding proteins. Early B-cell factor (EBF), which is crucial for B-cell lineage specification, reprograms mb-1 (Ig-␣) promoters by increasing chromatin accessibility and initiating the loss of DNA methylation. In turn, this facilitates promoter activation by Pax5. Here, we investigated the roles of ATP-dependent CRCs in these mechanisms. Fusion of EBF and Pax5 with the ligand-binding domain of ER␣ allowed for 4-hydroxytamoxifen-dependent, synergistic activation of mb-1 transcription in plasmacytoma cells. Knockdown of the SWI/SNF ATPases Brg1 and Brm inhibited transcriptional activation by EBF:ER and Pax5:ER. In contrast, knock-down of the Mi-2/NuRD complex subunit Mi-2␤ greatly enhanced chromatin accessibility and mb-1 transcription in response to the activators. The reduction of Mi-2␤ also propagated DNA demethylation in response to EBF:ER and Pax5:ER, resulting in fully unmethylated mb-1 promoters. In EBF-or EBF/Pax5-deficient fetal liver cells, both EBF and Pax5 were required for efficient demethylation of mb-1 promoters. Together, our data suggest that Mi-2/NuRD is important for the maintenance of hypermethylated chromatin in B cells. We conclude that SWI/SNF and Mi-2/NuRD function in opposition to enable or limit the reprogramming of genes by EBF and Pax5 during B-cell development.DNA methylation ͉ mb-1 promoter ͉ Cd19 promoter ͉ chromatin accessibility T he development of B cells from progenitor cells in the bone marrow is controlled by a network of transcriptional regulators (reviewed in 1). Early B-cell Factor (EBF; also known as EBF1/O/E-1/COE1) plays an integral role in this network and has been implicated as a major determinant of the B-cell fate (2, 3). In the absence of EBF, B-cell development is arrested at an early progenitor stage (3, 4). EBF is essential for the rearrangement and expression of Ig (Ig) genes in B cells and is required for expression of the B-cell commitment factor Pax5. EBF and Pax5 synergistically activate transcription of B cell-specific genes including mb-1 (Cd79a), which encodes the Ig-␣ subunit of the pre-B and B-cell receptors (5). We have proposed that EBF functions as a 'pioneer' factor by controlling the epigenetic states of its target genes (6). In response to EBF, the accessibility of mb-1 promoter chromatin is increased, while DNA methylation of the promoter is decreased.Specific biochemical interactions necessary for the pioneer functions of EBF have not been identified. However, transitions between active and inactive states of chromatin can be mediated by the recruitment of chromatin-remodeling complexes (CRCs) by transcription factors (7). CRCs serve as 'molecular motors' that mediate changes in the relative positions of nucleosomes. In this regard, CRCs of the mammalian SWI/SNF (related to yeast switch/sucrose non-Fermenter) subfamily ...

IMPORTANCE Approximately 24 million US individuals receive care at federally qualified health centers, which historically have low rates of colorectal cancer screening. The US Preventive Services Task Force recommends routine colorectal cancer screening for individuals aged 50 to 75 years. OBJECTIVE To determine the effectiveness of an electronic health record (EHR)-embedded mailed fecal immunochemical test (FIT) outreach program implemented in health centers as part of standard care. DESIGN, SETTING, AND PARTICIPANTS This cluster randomized pragmatic clinical trial was conducted in 26 federally qualified health center clinics, representing 8 health centers in Oregon and California, randomized to intervention (n = 13) or usual care (n = 13). All participants were overdue for colorectal cancer screening during the accrual interval (February 4, 2014 to February 3, 2015). INTERVENTIONS Electronic health record-embedded tools to identify eligible adults and to facilitate implementation of a stepwise mailed intervention involving (1) an introductory letter, (2) a mailed FIT, and (3) a reminder letter; training, collaborative learning, and facilitation through a practice improvement process. MAIN OUTCOMES AND MEASURES Effectiveness was measured as clinic-level proportions of adults who completed a FIT, and secondarily, any colorectal cancer screening within 12 months of accrual or by August 3, 2015. Implementation was measured as clinic-level proportions of adults who were mailed an introductory letter and ordered a FIT. RESULTS Twenty-six clinics with 41 193 adults (mean [SD] age, 58.5 [6.3] years; 22 994 women) were randomized to receive the direct mail colorectal screening intervention (13 clinics; 21 134 patients) or usual care (13 clinics; 20 059 patients). Compared with usual care clinics, intervention clinics had significantly higher adjusted clinic-level proportion of participants who completed a FIT (13.9% vs 10.4%; difference, 3.4 percentage points; 95% CI, 0.1%-6.8%) and any colorectal cancer screening (18.3% vs 14.5%; difference, 3.8 percentage points; 95% CI, 0.6%-7.0%). We observed large variation across health centers in effectiveness (FIT completion differences range, −7.4 percentage points to 17.6 percentage points) and implementation (proportion who were mailed a FIT range, 6.5% to 68.2%). The number needed to mail to achieve a completed FIT was 4.8 overall, and 4.0 in clinics that mailed a FIT reminder. CONCLUSIONS AND RELEVANCE An EHR-embedded mailed FIT outreach intervention significantly improved rates of FIT completion and rates of any colorectal cancer screening. Higher rates of colorectal cancer screening occurred in clinics that successfully implemented the mailed outreach program. TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT01742065

The ADVANCE (Accelerating Data Value Across a National Community Health Center Network) clinical data research network (CDRN) is led by the OCHIN Community Health Information Network in partnership with Health Choice Network and Fenway Health. The ADVANCE CDRN will ‘horizontally’ integrate outpatient electronic health record data for over one million federally qualified health center patients, and ‘vertically’ integrate hospital, health plan, and community data for these patients, often under-represented in research studies. Patient investigators, community investigators, and academic investigators with diverse expertise will work together to meet project goals related to data integration, patient engagement and recruitment, and the development of streamlined regulatory policies. By enhancing the data and research infrastructure of participating organizations, the ADVANCE CDRN will serve as a ‘community laboratory’ for including disadvantaged and vulnerable patients in patient-centered outcomes research that is aligned with the priorities of patients, clinics, and communities in our network.