24 research outputs found
Sub-Nuclear Localization and Tumorigenic Function of the Oncoprotein Dek.
The human DEK gene is overexpressed in a number of malignancies, however its potential function in the context of cancer remains unknown. DEK has been implicated in a diverse set of cellular processes, including regulation of transcription, chromatin architecture, mRNA processing, and cell signaling. Regulation of the participation of DEK in these disparate functions is thought to be achieved through differential post-translational modification. We demonstrate that a fraction of nuclear DEK is acetylated in vivo. Acetylation of DEK results in the accumulation of DEK in interchromatin granule clusters, dense sub-nuclear structures enriched in mRNA processing factors. Overexpression of the acetylase p300/CBP-associated factor was sufficient to cause migration of DEK into interchromatin granule clusters. Inhibition of transcription similarly altered the sub-nuclear distribution of DEK, causing accumulation of DEK in both interchromatin granule clusters, as well as other sub-nuclear structures.
The significance of DEK overexpression in melanoma was also addressed. Metastatic melanoma lines displayed remarkably increased expression of DEK as compared to normal melanocytes. Inhibition of DEK expression by shRNA interference revealed two oncogenic contributions of DEK. Knockdown of DEK expression resulted in the induction of the cyclin-dependent kinase inhibitor p21CIP1. In some, but not all melanomas, the expression of p21CIP1 was accompanied by the induction of cellular senescence. These findings suggest that overexpression of DEK may represent an event in melanoma development required to evade tumor suppression through cell cycle arrest and senescence.
In addition to its anti-senescence function, DEK overexpression in melanoma also conferred remarkable chemoresistance to both the DNA damaging agent doxorubicin and the BH3 mimetic compound TW-37. This effect was independent of p53, as inhibition of DEK expression did not alter p53 accumulation or activity in response to doxorubicin. Instead, knockdown of DEK expression sensitized melanoma through downregulation of a member of the anti-apoptotic Bcl-2 family, Mcl-1. Knockdown of DEK expression resulted in reduced activity of the mcl-1 promoter and consequently reduced mcl-1 mRNA. These results demonstrate a novel transcriptional mechanism of Mcl-1 overexpression in melanoma that confers remarkable chemoresistance. This work establishes DEK as a melanoma oncoprotein with both anti-senescence and anti-apoptotic functions.Ph.D.ImmunologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/75982/1/mkhodado_1.pd
Transcript-indexed ATAC-seq for precision immune profiling.
T cells create vast amounts of diversity in the genes that encode their T cell receptors (TCRs), which enables individual clones to recognize specific peptide-major histocompatibility complex (MHC) ligands. Here we combined sequencing of the TCR-encoding genes with assay for transposase-accessible chromatin with sequencing (ATAC-seq) analysis at the single-cell level to provide information on the TCR specificity and epigenomic state of individual T cells. By using this approach, termed transcript-indexed ATAC-seq (T-ATAC-seq), we identified epigenomic signatures in immortalized leukemic T cells, primary human T cells from healthy volunteers and primary leukemic T cells from patient samples. In peripheral blood CD4+ T cells from healthy individuals, we identified cis and trans regulators of naive and memory T cell states and found substantial heterogeneity in surface-marker-defined T cell populations. In patients with a leukemic form of cutaneous T cell lymphoma, T-ATAC-seq enabled identification of leukemic and nonleukemic regulatory pathways in T cells from the same individual by allowing separation of the signals that arose from the malignant clone from the background T cell noise. Thus, T-ATAC-seq is a new tool that enables analysis of epigenomic landscapes in clonal T cells and should be valuable for studies of T cell malignancy, immunity and immunotherapy
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
Antigen presentation profiling reveals recognition of lymphoma immunoglobulin neoantigens.
Low-dose total skin electron beam therapy for refractory cutaneous CD30 positive lymphoproliferative disorders
Low-Dose Total Skin Electron Beam Therapy Combined With Mogamulizumab for Refractory Mycosis Fungoides and Sézary Syndrome
Purpose: Management of patients with refractory mycosis fungoides and Sézary syndrome (SS) is often challenging, as available therapies lack durable response and consistent activity across disease compartments. Combining low-dose total skin electron beam therapy (LD-TSEBT) upfront with mogamulizumab could optimize the clinical outcome of these patients. LD-TSEBT is effective in clearing skin disease, and mogamulizumab is an antitumor immunotherapy with long-term tolerability, suggesting its potential as a maintenance therapy after maximal response. We examine the combination regimen in patients with SS who were previously treated. Methods and Materials: Two patients with SS were treated with combination LD-TSEBT and mogamulizumab. Both patients received mogamulizumab 1 mg/kg weekly × 4 and then bi-weekly; LD-TSEBT (12 Gy) was initiated within 2 days of starting mogamulizumab and given over 2-3 weeks. Safety and clinical response were evaluated. Results: Total skin electron beam therapy plus mogamulizumab (TSE-Moga) was well-tolerated without any unanticipated adverse events. Patient 1 (T4N2bM0B2) was a 63-year-old woman with 4 prior systemic therapies; time to global response with TSE-Moga was 9 weeks. Patient 2 (T4NxM0B2) was a 75-year-old man with 5 prior systemic therapies; time to global response was 4 weeks. Both patients lacked global response to their prior therapies but achieved global complete response (blood and skin) with TSE-Moga. After a follow-up of 72 weeks and 43 weeks, respectively, global complete response continued. Conclusions: TSE-Moga demonstrated excellent tolerability and promising clinical activity with ongoing global complete responses in 2 patients with refractory SS. This encouraging experience supports our ongoing clinical trial evaluating the efficacy and safety of TSE-Moga in mycosis fungoides and SS
The DEK Nuclear Autoantigen Is a Secreted Chemotactic Factor
The nuclear DNA-binding protein DEK is an autoantigen that has been implicated in the regulation of transcription, chromatin architecture, and mRNA processing. We demonstrate here that DEK is actively secreted by macrophages and is also found in synovial fluid samples from patients with juvenile arthritis. Secretion of DEK is modulated by casein kinase 2, stimulated by interleukin-8, and inhibited by dexamethasone and cyclosporine A, consistent with a role as a proinflammatory molecule. DEK is secreted in both a free form and in exosomes, vesicular structures in which transcription-modulating factors such as DEK have not previously been found. Furthermore, DEK functions as a chemotactic factor, attracting neutrophils, CD8(+) T lymphocytes, and natural killer cells. Therefore, the DEK autoantigen, previously described as a strictly nuclear protein, is secreted and can act as an extracellular chemoattractant, suggesting a direct role for DEK in inflammation
The DEK oncoprotein is a Su(var) that is essential to heterochromatin integrity
Heterochromatin integrity is crucial for genome stability and regulation of gene expression, but the factors involved in mammalian heterochromatin biology are only incompletely understood. Here we identify the oncoprotein DEK, an abundant nuclear protein with a previously enigmatic in vivo function, as a Suppressor of Variegation [Su(var)] that is crucial to global heterochromatin integrity. We show that DEK interacts directly with Heterochromatin Protein 1 α (HP1α) and markedly enhances its binding to trimethylated H3K9 (H3K9me3), which is key for maintaining heterochromatic regions. Loss of Dek in Drosophila leads to a Su(var) phenotype and global reduction in heterochromatin. Thus, these findings show that DEK is a key factor in maintaining the balance between heterochromatin and euchromatin in vivo