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1.
Front Digit Health ; 6: 1345451, 2024.
Article En | MEDLINE | ID: mdl-38628625

Recent improvements in the accessibility of mapping tools and an increased recognition of the importance of leveraging data to inform public health operations has led to enthusiasm among public health departments to rapidly evolve their ability to analyze and apply data to programs. As the COVID-19 pandemic made evident, many health department data systems have been neglected for decades and data literacy among staff low. Significant federal dollars have been allocated to local health departments to modernize health systems. This case study recounts the effort to equip the Pima County Health Department with a highly sophisticated "COVID-19 Vaccines Solutions Dashboard" in 2021-2022, quantifying community vulnerability in the midst of the COVID-19 pandemic and shares key successes and challenges in process and outcomes that can guide other such dashboard initiatives. The experience informed the development of Pima' County Health Department's Data & Informatics Team as well as efforts to cultivate a more robust data culture throughout the department. Many health departments around the United States are in a similar position, and these lessons learned are widely applicable.

2.
Biomolecules ; 13(12)2023 11 28.
Article En | MEDLINE | ID: mdl-38136588

Parent-of-origin-dependent gene expression of a few hundred human genes is achieved by differential DNA methylation of both parental alleles. This imprinting is required for normal development, and defects in this process lead to human disease. Induced pluripotent stem cells (iPSCs) serve as a valuable tool for in vitro disease modeling. However, a wave of de novo DNA methylation during reprogramming of iPSCs affects DNA methylation, thus limiting their use. The DNA methyltransferase 3B (DNMT3B) gene is highly expressed in human iPSCs; however, whether the hypermethylation of imprinted loci depends on DNMT3B activity has been poorly investigated. To explore the role of DNMT3B in mediating de novo DNA methylation at imprinted DMRs, we utilized iPSCs generated from patients with immunodeficiency, centromeric instability, facial anomalies type I (ICF1) syndrome that harbor biallelic hypomorphic DNMT3B mutations. Using a whole-genome array-based approach, we observed a gain of methylation at several imprinted loci in control iPSCs but not in ICF1 iPSCs compared to their parental fibroblasts. Moreover, in corrected ICF1 iPSCs, which restore DNMT3B enzymatic activity, imprinted DMRs did not acquire control DNA methylation levels, in contrast to the majority of the hypomethylated CpGs in the genome that were rescued in the corrected iPSC clones. Overall, our study indicates that DNMT3B is responsible for de novo methylation of a subset of imprinted DMRs during iPSC reprogramming and suggests that imprinting is unstable during a specific time window of this process, after which the epigenetic state at these regions becomes resistant to perturbation.


Immunologic Deficiency Syndromes , Induced Pluripotent Stem Cells , Humans , Induced Pluripotent Stem Cells/metabolism , DNA (Cytosine-5-)-Methyltransferases/genetics , DNA (Cytosine-5-)-Methyltransferases/metabolism , DNA Methylation , Mutation , Immunologic Deficiency Syndromes/genetics , Genomic Imprinting
3.
Pigment Cell Melanoma Res ; 36(6): 542-556, 2023 Nov.
Article En | MEDLINE | ID: mdl-37804122

Mucosal melanoma remains a rare cancer with high mortality and a paucity of therapeutic options. This is due in significant part to its low incidence leading to limited patient access to expert care and downstream clinical/basic science data for research interrogation. Clinical challenges such as delayed and at times inaccurate diagnoses, and lack of consensus tumor staging have added to the suboptimal outcomes for these patients. Clinical trials, while promising, have been difficult to activate and accrue. While individual institutions and investigators have attempted to seek solutions to such problems, international, national, and local partnership may provide the keys to more efficient and innovative paths forward. Furthermore, a mucosal melanoma coalition would provide a potential network for patients and caregivers to seek expert opinion and advice. The Melanoma Research Foundation Mucosal Melanoma Meeting (December 16, 2022, New York, USA) highlighted the current clinical challenges faced by patients, providers, and scientists, identified current and future clinical trial investigations in this rare disease space, and aimed to increase national and international collaboration among the mucosal melanoma community in an effort to improve patient outcomes. The included proceedings highlight the clinical challenges of mucosal melanoma, global clinical trial experience, basic science advances in mucosal melanoma, and future directions, including the creation of shared rare tumor registries and enhanced collaborations.


Melanoma , Humans , New York , Melanoma/therapy , Melanoma/pathology , Mucous Membrane/pathology , Combined Modality Therapy , Neoplasm Staging
4.
Genome Res ; 33(2): 169-183, 2023 02.
Article En | MEDLINE | ID: mdl-36828588

Bi-allelic hypomorphic mutations in DNMT3B disrupt DNA methyltransferase activity and lead to immunodeficiency, centromeric instability, facial anomalies syndrome, type 1 (ICF1). Although several ICF1 phenotypes have been linked to abnormally hypomethylated repetitive regions, the unique genomic regions responsible for the remaining disease phenotypes remain largely uncharacterized. Here we explored two ICF1 patient-derived induced pluripotent stem cells (iPSCs) and their CRISPR-Cas9-corrected clones to determine whether DNMT3B correction can globally overcome DNA methylation defects and related changes in the epigenome. Hypomethylated regions throughout the genome are highly comparable between ICF1 iPSCs carrying different DNMT3B variants, and significantly overlap with those in ICF1 patient peripheral blood and lymphoblastoid cell lines. These regions include large CpG island domains, as well as promoters and enhancers of several lineage-specific genes, in particular immune-related, suggesting that they are premarked during early development. CRISPR-corrected ICF1 iPSCs reveal that the majority of phenotype-related hypomethylated regions reacquire normal DNA methylation levels following editing. However, at the most severely hypomethylated regions in ICF1 iPSCs, which also display the highest increases in H3K4me3 levels and/or abnormal CTCF binding, the epigenetic memory persists, and hypomethylation remains uncorrected. Overall, we demonstrate that restoring the catalytic activity of DNMT3B can reverse the majority of the aberrant ICF1 epigenome. However, a small fraction of the genome is resilient to this rescue, highlighting the challenge of reverting disease states that are due to genome-wide epigenetic perturbations. Uncovering the basis for the persistent epigenetic memory will promote the development of strategies to overcome this obstacle.


Induced Pluripotent Stem Cells , Induced Pluripotent Stem Cells/metabolism , Epigenome , Epigenetic Memory , Histones/metabolism , DNA Methylation , DNA (Cytosine-5-)-Methyltransferases/genetics
5.
Front Oncol ; 12: 1004014, 2022.
Article En | MEDLINE | ID: mdl-36300096

Among the main metabolic pathways implicated in cancer cell proliferation are those of cholesterol and fatty acid synthesis, both of which are tightly regulated by sterol regulatory element-binding proteins (SREBPs). SREBPs are activated through specific cleavage by membrane-bound transcription factor protease 1 (MBTPS1), a serine protease that cleaves additional substrates (ATF6, BDNF, CREBs and somatostatin), some of which are also implicated in cell proliferation. The goal of this study was to determine whether MBTPS1 may serve as a master regulator in proliferation of colorectal cancer (CRC). Tumors from CRC patients showed variable levels of MBTPS1 mRNA, which were in positive correlation with the levels of SREBPs and ATF6, and in reverse correlation with BDNF levels. Chemical inhibition of MBTPS1 activity in two CRC-derived cell lines resulted in a marked decrease in the levels of SREBPs, but not of its other substrates and a marked decrease in cell proliferation, which suggested that MBTPS1 activity is critical for proliferation of these cells. In accordance, CRISPR/Cas9 targeted knockout (KO) of the MBTPS1 gene resulted in the survival of only a single clone that presented a phenotype of severely attenuated proliferation and marked downregulation of several energy metabolism pathways. We further showed that survival of the MBTPS1 KO clone was dependent upon significant upregulation of the type-1 interferon pathway, the inhibition of which halted proliferation entirely. Finally, rescue of the MBTPS1 KO cells, resulted in partial restoration of MBTPS1 levels, which was in accordance with partial recovery in proliferation and in SREBP levels. These finding suggest that MBTPS1 plays a critical role in regulating colon cancer proliferation primarily through SREBP-associated lipid metabolism, and as such may serve as a possible therapeutic target in CRC.

6.
Melanoma Manag ; 9(3): MMT62, 2022 Sep.
Article En | MEDLINE | ID: mdl-36147875

Aim: This study explored uveal melanoma patient experiences and regret following molecular prognostic testing using a 15-gene expression profile (GEP) test. Materials & methods: A retrospective, cross-sectional survey study was conducted through an online questionnaire capturing patient-reported experiences with prognostic biopsy/molecular testing. Results: Of 177 respondents, 159 (90%) wanted prognostic information at diagnosis. Most 15-GEP-tested patients who shared their results (99%) reported gaining value from testing, as did patients tested with other methods. Patients who received prognostic testing experienced lower decision regret than those who opted out. Decision regret did not differ based on GEP class. Conclusion: Most uveal melanoma patients desire prognostic testing and gain value from the GEP, independent of a high- or low-risk result.


Uveal melanoma is a rare but aggressive eye cancer, resulting in distant metastasis in nearly 50% of patients. Molecular prognostic testing is often employed to determine who is at high or low risk of developing metastatic disease. A prognostic 15-gene expression profiling (GEP) test is commonly used throughout the USA and parts of Canada. The goal of this survey was to assess patient experiences with the 15-GEP and other prognostic methods. Of the 177 patients who participated in the survey, the majority reported that they wanted prognostic information at the time of diagnosis. Of patients who underwent 15-GEP testing, nearly all reported gaining value from their test result, regardless of their individual risk profile. This study supports prior findings using other prognostic methods that patients prefer information about their risk of metastasis and reinforces the importance of discussing prognostic testing options with newly diagnosed uveal melanoma patients.

7.
Cancers (Basel) ; 14(3)2022 Jan 30.
Article En | MEDLINE | ID: mdl-35159001

Although the relative risk of renal cell carcinoma associated with chronic kidney injury is particularly high among sub-Saharan African ancestry populations, it is unclear yet whether the APOL1 gene risk variants (RV) for kidney disease additionally elevate this risk. APOL1 G1 and G2 RV contribute to increased risk for kidney disease in black populations, although the disease mechanism has still not been fully deciphered. While high expression levels of all three APOL1 allelic variants, G0 (the wild type allele), G1, and G2 are injurious to normal human cells, renal carcinoma cells (RCC) naturally tolerate inherent high expression levels of APOL1. We utilized CRISPR/Cas9 gene editing to generate isogenic RCC clones expressing APOL1 G1 or G2 risk variants on a similar genetic background, thus enabling a reliable comparison between the phenotypes elicited in RCC by each of the APOL1 variants. Here, we demonstrate that knocking in the G1 or G2 APOL1 alleles, or complete elimination of APOL1 expression, has major effects on proliferation capacity, mitochondrial morphology, cell metabolism, autophagy levels, and the tumorigenic potential of RCC cells. The most striking effect of the APOL1 RV effect was demonstrated in vivo by the complete abolishment of tumor growth in immunodeficient mice. Our findings suggest that, in contrast to the WT APOL1 variant, APOL1 RV are toxic for RCC cells and may act to suppress cancer cell growth. We conclude that the inherent expression of non-risk APOL1 G0 is required for RCC tumorigenicity. RCC cancer cells can hardly tolerate increased APOL1 risk variants expression levels as opposed to APOL1 G0.

8.
J Hum Genet ; 66(11): 1101-1112, 2021 Nov.
Article En | MEDLINE | ID: mdl-33980986

RBL2/p130, a member of the retinoblastoma family of proteins, is a key regulator of cell division and propagates irreversible senescence. RBL2/p130 is also involved in neuronal differentiation and survival, and eliminating Rbl2 in certain mouse strains leads to embryonic lethality accompanied by an abnormal central nervous system (CNS) phenotype. Conflicting reports exist regarding a role of RBL2/p130 in transcriptional regulation of DNA methyltransferases (DNMTs), as well as the control of telomere length. Here we describe the phenotype of three patients carrying bi-allelic RBL2-truncating variants. All presented with infantile hypotonia, severe developmental delay and microcephaly. Malignancies were not reported in carriers or patients. Previous studies carried out on mice and human cultured cells, associated RBL2 loss to DNA methylation and telomere length dysregulation. Here, we investigated whether patient cells lacking RBL2 display related abnormalities. The study of primary patient fibroblasts did not detect abnormalities in expression of DNMTs. Furthermore, methylation levels of whole genome DNA, and specifically of pericentromeric repeats and subtelomeric regions, were unperturbed. RBL2-null fibroblasts show no evidence for abnormal elongation by telomeric recombination. Finally, gradual telomere shortening, and normal onset of senescence were observed following continuous culturing of RBL2-mutated fibroblasts. Thus, this study resolves uncertainties regarding a potential non-redundant role for RBL2 in DNA methylation and telomere length regulation, and indicates that loss of function variants in RBL2 cause a severe autosomal recessive neurodevelopmental disorder in humans.


Cognitive Dysfunction/genetics , DNA Methylation/genetics , Retinoblastoma-Like Protein p130/genetics , Telomere Shortening/genetics , Adolescent , Adult , Alleles , Animals , Child , Cognitive Dysfunction/complications , Cognitive Dysfunction/physiopathology , Developmental Disabilities/complications , Developmental Disabilities/genetics , Developmental Disabilities/physiopathology , Female , Fibroblasts/metabolism , Genetic Predisposition to Disease , Humans , Male , Methyltransferases/genetics , Mice , Microcephaly/complications , Microcephaly/genetics , Microcephaly/physiopathology , Motor Activity/physiology , Muscle Hypotonia/complications , Muscle Hypotonia/genetics , Muscle Hypotonia/physiopathology , Telomere/genetics , Exome Sequencing
9.
Transl Vis Sci Technol ; 10(2): 24, 2021 02 05.
Article En | MEDLINE | ID: mdl-34003909

Purpose: To discuss the evolution of noninvasive diagnostic methods in the identification of choroidal nevus and determination of risk factors for malignant transformation as well as introduce the novel role that artificial intelligence (AI) can play in the diagnostic process. Methods: White paper. Results: Longstanding diagnostic methods to stratify benign choroidal nevus from choroidal melanoma and to further determine the risk for nevus transformation into melanoma have been dependent on recognition of key clinical features by ophthalmic examination. These risk factors have been derived from multiple large cohort research studies over the past several decades and have garnered widespread use throughout the world. More recent publications have applied ocular diagnostic testing (fundus photography, ultrasound examination, autofluorescence, and optical coherence tomography) to identify risk factors for the malignant transformation of choroidal nevus based on multimodal imaging features. The widespread usage of ophthalmic imaging systems to identify and follow choroidal nevus, in conjunction with the characterization of malignant transformation risk factors via diagnostic imaging, presents a novel path to apply AI. Conclusions: AI applied to existing ophthalmic imaging systems could be used for both identification of choroidal nevus and as a tool to aid in earlier detection of transformation to malignant melanoma. Translational Relevance: Advances in AI models applied to ophthalmic imaging systems have the potential to improve patient care, because earlier detection and treatment of melanoma has been proven to improve long-term clinical outcomes.


Melanoma , Nevus , Skin Neoplasms , Artificial Intelligence , Humans , Melanoma/diagnosis , Nevus/diagnostic imaging , Skin Neoplasms/diagnosis , Tomography, Optical Coherence
10.
Life (Basel) ; 11(4)2021 Mar 26.
Article En | MEDLINE | ID: mdl-33810393

Most human cancers circumvent senescence by activating a telomere length maintenance mechanism, most commonly involving telomerase activation. A minority of cancers utilize the recombination-based alternative lengthening of telomeres (ALT) pathway. The exact requirements for unleashing normally repressed recombination at telomeres are yet unclear. Epigenetic modifications at telomeric regions were suggested to be pivotal for activating ALT; however, conflicting data exist regarding their exact nature and necessity. To uncover common ALT-positive epigenetic characteristics, we performed a comprehensive analysis of subtelomeric DNA methylation, histone modifications, and TERRA expression in several ALT-positive and ALT-negative cell lines. We found that subtelomeric DNA methylation does not differentiate between the ALT-positive and ALT-negative groups, and most of the analyzed subtelomeres within each group do not share common DNA methylation patterns. Additionally, similar TERRA levels were measured in the ALT-positive and ALT-negative groups, and TERRA levels varied significantly among the members of the ALT-positive group. Subtelomeric H3K4 and H3K9 trimethylation also differed significantly between samples in the ALT-positive group. Our findings do not support a common route by which epigenetic modifications activate telomeric recombination in ALT-positive cells, and thus, different therapeutic approaches will be necessary to overcome ALT-dependent cellular immortalization.

11.
Clin Cancer Res ; 27(1): 28-33, 2021 01 01.
Article En | MEDLINE | ID: mdl-33060121

Uveal melanoma is a rare cancer in adults, but its treatment is one of the clinical unmet needs in the melanoma field. Metastatic disease develops in approximately 50% of patients and is associated with poor survival due to the lack of effective treatment options. It provides a paradigm for cancers that show evidence of aberrant G protein-coupled receptor signaling, tumor dormancy, and liver-selective metastatic tropism and are associated with the loss of the BAP1 tumor suppressor. At the Melanoma Research Foundation CURE OM Science Meeting at the Society for Melanoma Research Meeting held in Utah on November 20, 2019, clinicians and researchers presented findings from their studies according to three themes within uveal melanoma: (i) ongoing clinical trials, (ii) molecular determinants, and (iii) novel targets that could be translated into clinical trials. This meeting underscored the high interest in the uveal melanoma research field and the unmet need for effective treatment strategies for late-stage disease. Findings from ongoing clinical trials are promising, and multiple studies show how novel combinatorial strategies increase response rates. Novel targets and tumor vulnerabilities identified bioinformatically or through high-throughput screens also reveal new opportunities to target uveal melanoma. The future directions pursued by the uveal melanoma research field will likely have an impact on other cancer types that harbor similar genetic alterations and/or show similar biological properties.


Antineoplastic Agents/therapeutic use , Biomarkers, Tumor/antagonists & inhibitors , Melanoma/drug therapy , Uveal Neoplasms/drug therapy , Biomarkers, Tumor/genetics , Clinical Trials as Topic , Computational Biology , Congresses as Topic , High-Throughput Screening Assays , Humans , Medical Oncology/methods , Medical Oncology/organization & administration , Melanoma/genetics , Molecular Targeted Therapy/methods , Societies, Medical , Uveal Neoplasms/genetics
12.
Hum Mol Genet ; 29(19): 3197-3210, 2020 11 25.
Article En | MEDLINE | ID: mdl-32916696

The most distal 2 kb region in the majority of human subtelomeres contains CpG-rich promoters for TERRA, a long non-coding RNA. When the function of the de novo DNA methyltransferase DNMT3B is disrupted, as in ICF1 syndrome, subtelomeres are abnormally hypomethylated, subtelomeric heterochromatin acquires open chromatin characteristics, TERRA is highly expressed, and telomeres shorten rapidly. In this study, we explored whether the regulation of subtelomeric epigenetic characteristics by DNMT3B is conserved between humans and mice. Studying the DNA sequence of the distal 30 kb of the majority of murine q-arm subtelomeres indicated that these regions are relatively CpG-poor and do not contain TERRA promoters similar to those present in humans. Despite the lack of human-like TERRA promoters, we clearly detected TERRA expression originating from at least seven q-arm subtelomeres, and at higher levels in mouse pluripotent stem cells in comparison with mouse embryonic fibroblasts (MEFs). However, these differences in TERRA expression could not be explained by differential methylation of CpG islands present in the TERRA-expressing murine subtelomeres. To determine whether Dnmt3b regulates the expression of TERRA in mice, we characterized subtelomeric methylation and associated telomeric functions in cells derived from ICF1 model mice. Littermate-derived WT and ICF1 MEFs demonstrated no significant differences in subtelomeric DNA methylation, chromatin modifications, TERRA expression levels, telomere sister chromatid exchange or telomere length. We conclude that the epigenetic characteristics of murine subtelomeres differ substantially from their human counterparts and that TERRA transcription in mice is regulated by factors others than Dnmt3b.


DNA (Cytosine-5-)-Methyltransferases/metabolism , DNA Methylation , DNA-Binding Proteins/metabolism , Face/abnormalities , Fibroblasts/pathology , Primary Immunodeficiency Diseases/pathology , Telomere/physiology , Transcription Factors/metabolism , Animals , CpG Islands , DNA (Cytosine-5-)-Methyltransferases/genetics , DNA-Binding Proteins/genetics , Face/pathology , Fibroblasts/metabolism , Humans , Mice , Primary Immunodeficiency Diseases/genetics , Promoter Regions, Genetic , Transcription Factors/genetics , Transcription, Genetic , DNA Methyltransferase 3B
13.
Curr Dev Nutr ; 4(8): nzaa109, 2020 Aug.
Article En | MEDLINE | ID: mdl-32734135

BACKGROUND: Rates of childhood obesity are higher in American Indian and Alaska Native populations, and food insecurity plays a major role in diet-related disparities. To address this need, local healthcare providers and a local nonprofit launched the Navajo Fruit and Vegetable Prescription (FVRx) Program in 2015. Children up to 6 y of age and their caregivers are enrolled in the 6-mo program by healthcare providers. Families attend monthly health coaching sessions where they receive vouchers redeemable for fruits, vegetables, and healthy traditional foods at retailers participating in the FVRx program. OBJECTIVES: We assessed the impact of a fruit and vegetable prescription program on the health outcomes and behaviors of participating children. METHODS: Caregivers completed voluntary surveys to assess food security, fruit and vegetable consumption, hours of sleep, and minutes of physical activity; healthcare providers also measured children's body mass index [BMI (kg/m2)] z score at initiation and completion of the program. We calculated changes in health behaviors, BMI, and food security at the end of the program, compared with baseline values. RESULTS: A total of 243 Navajo children enrolled in Navajo FVRx between May 2015 and September 2018. Fruit and vegetable consumption significantly increased from 5.2 to 6.8 servings per day between initiation and program completion (P < 0.001). The proportion of participant households reporting food insecurity significantly decreased from 82% to 65% (P < 0.001). Among children classified as overweight or obese at baseline, 38% achieved a healthy BMI z score at program completion (P < 0.001). Sixty-five percent of children were retained in the program. CONCLUSIONS: The Navajo FVRx program improves fruit and vegetable consumption among young children. Children who are obese or overweight may benefit most from the program.

14.
Public Health Nutr ; 23(12): 2199-2210, 2020 08.
Article En | MEDLINE | ID: mdl-32398182

OBJECTIVE: To utilise a community-based participatory approach in the design and implementation of an intervention targeting diet-related health problems on Navajo Nation. DESIGN: A dual strategy approach of community needs/assets assessment and engagement of cross-sectorial partners in programme design with systematic cyclical feedback for programme modifications. SETTING: Navajo Nation, USA. PARTICIPANTS: Navajo families with individuals meeting criteria for programme enrolment. Participant enrolment increased with iterative cycles. RESULTS: The Navajo Fruit and Vegetable Prescription (FVRx) Programme. CONCLUSIONS: A broad, community-driven and culturally relevant programme design has resulted in a programme able to maintain core programmatic principles, while also allowing for flexible adaptation to changing needs.


Diet, Healthy , Food Deserts , Fruit , Vegetables , Food Supply , Health Promotion , Humans , Prescriptions , Program Evaluation , Southwestern United States , American Indian or Alaska Native
15.
Curr Opin Genet Dev ; 60: 9-16, 2020 02.
Article En | MEDLINE | ID: mdl-32109830

Subtelomeres are the regions at chromosome ends, immediately adjacent to the terminal telomeric repeats. The majority of human subtelomeres are CpG-rich in their distal two kilobases, and are methylated during early embryonic development by the de novo DNA methyltransferase DNMT3B. The biological relevance of subtelomeric DNA methylation is highlighted by the presence of promoters for the long non-coding TERRA transcripts in these CpG-rich regions. Indeed, deviant subtelomeric methylation has been linked with abnormal telomeric phenotypes, as most strikingly found in ICF syndrome. Here we review recent studies that explore new aspects of subtelomeric methylation regulation and demonstrate the significance of maintaining proper DNA methylation at the extreme distal human subtelomeric regions.


DNA Methylation , Gene Expression Regulation, Neoplastic , Neoplasms/genetics , Neoplasms/pathology , Telomere Homeostasis , Telomere , Humans , Promoter Regions, Genetic
16.
Elife ; 82019 11 20.
Article En | MEDLINE | ID: mdl-31738163

DNA methyltransferase 3B (DNMT3B) is the major DNMT that methylates mammalian genomes during early development. Mutations in human DNMT3B disrupt genome-wide DNA methylation patterns and result in ICF syndrome type 1 (ICF1). To study whether normal DNA methylation patterns may be restored in ICF1 cells, we corrected DNMT3B mutations in induced pluripotent stem cells from ICF1 patients. Focusing on repetitive regions, we show that in contrast to pericentromeric repeats, which reacquire normal methylation, the majority of subtelomeres acquire only partial DNA methylation and, accordingly, the ICF1 telomeric phenotype persists. Subtelomeres resistant to de novo methylation were characterized by abnormally high H3K4 trimethylation (H3K4me3), and short-term reduction of H3K4me3 by pharmacological intervention partially restored subtelomeric DNA methylation. These findings demonstrate that the abnormal epigenetic landscape established in ICF1 cells restricts the recruitment of DNMT3B, and suggest that rescue of epigenetic diseases with genome-wide disruptions will demand further manipulation beyond mutation correction.


DNA (Cytosine-5-)-Methyltransferases/genetics , DNA Methylation/genetics , Face/abnormalities , Induced Pluripotent Stem Cells/metabolism , Primary Immunodeficiency Diseases/genetics , Epigenesis, Genetic/genetics , Face/pathology , Genome/genetics , Histones/genetics , Humans , Mutation , Primary Immunodeficiency Diseases/metabolism , Primary Immunodeficiency Diseases/pathology , Promoter Regions, Genetic/genetics , Telomere/genetics , DNA Methyltransferase 3B
17.
Hum Mol Genet ; 27(20): 3568-3581, 2018 10 15.
Article En | MEDLINE | ID: mdl-30010917

Human telomeres and adjacent subtelomeres are packaged as heterochromatin. Subtelomeric DNA undergoes methylation during development by DNA methyltransferase 3B (DNMT3B), including the CpG-rich promoters of the long non-coding RNA (TERRA) embedded in these regions. The factors that direct DNMT3B methylation to human subtelomeres and maintain this methylation throughout lifetime are yet unknown. The importance of subtelomeric methylation is manifested through the abnormal telomeric phenotype in Immunodeficiency, Centromeric instability and Facial anomalies (ICF) syndrome type 1 patients carrying mutations in DNMT3B. Patient cells demonstrate subtelomeric hypomethylation, accompanied by elevated TERRA transcription, accelerated telomere shortening and premature senescence of fibroblasts. ICF syndrome can arise due to mutations in at least three additional genes, ZBTB24 (ICF2), CDCA7 (ICF3) and HELLS (ICF4). While pericentromeric repeat hypomethylation is evident in all ICF syndrome subtypes, the status of subtelomeric DNA methylation had not been described for patients of subtypes 2-4. Here we explored the telomeric phenotype in cells derived from ICF2-4 patients with the aim to determine whether ZBTB24, CDCA7 and HELLS also play a role in establishing and/or maintaining human subtelomeric methylation. We found normal subtelomeric methylation in ICF2-4 and accordingly low TERRA levels and unperturbed telomere length. Moreover, depleting the ICF2-4-related proteins in normal fibroblasts did not influence subtelomeric methylation. Thus, these gene products are not involved in establishing or maintaining subtelomeric methylation. Our findings indicate that human subtelomeric heterochromatin has specialized methylation regulation and highlight the telomeric phenotype as a characteristic that distinguishes ICF1 from ICF2-4.


Abnormalities, Multiple/genetics , DNA (Cytosine-5-)-Methyltransferases/genetics , DNA Helicases/genetics , DNA Methylation , Mutation , Nuclear Proteins/genetics , Repressor Proteins/genetics , Abnormalities, Multiple/metabolism , Adolescent , Adult , Cell Line , Centromere , Child , Child, Preschool , DNA (Cytosine-5-)-Methyltransferases/metabolism , DNA Helicases/metabolism , Face/abnormalities , Fibroblasts , Heterochromatin/metabolism , Humans , Immunologic Deficiency Syndromes/genetics , Immunologic Deficiency Syndromes/metabolism , Infant , Infant, Newborn , Nuclear Proteins/metabolism , Repressor Proteins/metabolism , Telomere/metabolism , Young Adult , DNA Methyltransferase 3B
18.
FEBS J ; 285(14): 2552-2566, 2018 07.
Article En | MEDLINE | ID: mdl-29637701

R-loops (RLs) are three-stranded nucleic acid structures that contain a DNA:RNA hybrid and a displaced DNA strand. Genomic regions with GC skew and a G-rich transcript are particularly prone to form RLs. RLs play important physiological roles in cells; however, when present at abnormally high levels, they may threaten genome stability. The perfect GC skew of telomeric repeats and the discovery of telomeric repeat-containing RNA (TERRA), a long noncoding transcript that consists of the G-rich telomeric sequence, make telomeric sequences the perfect candidates for generating RLs. Indeed, in the past 5 years, telomere R-loops (TRLs) have been demonstrated in Saccharomyces cerevisiae, Trypanosoma brucei, and human cells. The presence of TRLs in normal human cells that transcribe low levels of TERRA, suggests a physiological role for these nucleic structures in telomere maintenance. Abnormally enhanced TERRA transcription, as found in several human pathological conditions, leads to high TRL levels and various cellular outcomes, depending on the recombinogenic capabilities of the cells. Study of TRLs in various organisms highlights the necessity for tight regulation of these structures, which can switch from beneficial to detrimental under different conditions. Here, we review the current state of knowledge on TRLs, describe several means by which TRLs are regulated, and discuss how findings from yeast are relevant to human pathological scenarios in which TRLs are deregulated.


DNA/chemistry , Face/abnormalities , Genome , Immunologic Deficiency Syndromes/genetics , Nucleic Acid Hybridization , RNA, Long Noncoding/chemistry , Telomere/chemistry , Base Composition , DNA/genetics , DNA/metabolism , Face/pathology , Gene Expression Regulation , Genomic Instability , Humans , Immunologic Deficiency Syndromes/immunology , Immunologic Deficiency Syndromes/pathology , Nucleic Acid Conformation , Primary Immunodeficiency Diseases , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Telomere/metabolism , Telomere Homeostasis , Trypanosoma brucei brucei/genetics , Trypanosoma brucei brucei/metabolism
19.
Am J Public Health ; 107(S3): S223-S228, 2017 12.
Article En | MEDLINE | ID: mdl-29236539

Health professionals, including social workers, community health workers, public health workers, and licensed health care providers, share common interests and responsibilities in promoting health equity and improving social determinants of health-the conditions in which people live, work, play, and learn. We summarize the underlying causes of health inequity and comparatively poor health outcomes in the United States. We describe barriers to realizing the hope embedded in the 2010 Patient Protection and Affordable Care Act, that moving away from fee-for-service payments will naturally drive care upstream as providers respond to greater financial risk by undertaking greater prevention efforts for the health of their patients. We assert that health equity should serve as the guiding framework for achieving the Triple Aim of health care reform and outline practical opportunities for improving care and promoting stronger efforts to address social determinants of health. These proposals include developing a dashboard of measures to assist providers committed to health equity and community-based prevention and to promote institutional accountability for addressing socioeconomic factors that influence health.


Environmental Policy , Health Care Reform/organization & administration , Health Equity/organization & administration , Quality of Health Care , Community Health Workers , Female , Health Policy , Humans , Male , Patient Protection and Affordable Care Act
20.
Hum Mol Genet ; 26(21): 4244-4256, 2017 11 01.
Article En | MEDLINE | ID: mdl-28973513

Mutations in the de novo DNA methyltransferase DNMT3B lead to Immunodeficiency, Centromeric Instability and Facial anomalies (ICF) syndrome, type I. This syndrome is characterized, among other hypomethylated genomic loci, by severe subtelomeric hypomethylation that is associated with abnormally short telomere length. While it was demonstrated that the mean telomere length is significantly shorter in ICF type I cells, it is unknown whether all telomeres are equally vulnerable to shortening. To study this question we determined by combined telomere-FISH and spectral karyotyping the relative length of each individual telomere in lymphoblastoid cell lines (LCLs) generated from multiple ICF syndrome patients and control individuals. Here we confirm the short telomere lengths, and demonstrate that telomere length variance in the ICF patient group is much larger than in the control group, suggesting that not all telomeres shorten in a uniform manner. We identified a subgroup of telomeres whose relatively short lengths can distinguish with a high degree of certainty between a control and an ICF metaphase, proposing that in ICF syndrome cells, certain individual telomeres are consistently at greater risk to shorten than others. The majority of these telomeres display high sequence identity at the distal 2 kb of their subtelomeres, suggesting that the attenuation in DNMT3B methylation capacity affects individual telomeres to different degrees based, at least in part, on the adjacent subtelomeric sequence composition.


DNA (Cytosine-5-)-Methyltransferases/genetics , Telomere/genetics , Abnormalities, Multiple/genetics , Cell Line , Centromere/genetics , Centromere/physiology , Chromosome Aberrations , DNA (Cytosine-5-)-Methyltransferases/metabolism , DNA Methylation/genetics , Face/abnormalities , Female , High-Throughput Nucleotide Sequencing/methods , Humans , Immunologic Deficiency Syndromes/genetics , Immunologic Deficiency Syndromes/metabolism , Male , Mutation , Pedigree , Primary Immunodeficiency Diseases , Telomere/physiology , Telomere Shortening/genetics , DNA Methyltransferase 3B
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