bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deletion of a Key PU.1 Gene Regulatory Element Induces T-Cell Lymphoma.
Authors: Rosenbauer Frank , Steidl Ulrich , Owens Bronwyn , Clayton Linda , Wagner Katharina , Kutok Jeffery L. , Le Beau Michelle M. , Tenen Daniel G. 
Published: October 2019

Abstract
The transcription factor PU.1 is indispensable for the generation of myeloid and B-lymphoid cells. PU.1 expression is highly regulated, and enforced expression of PU.1 in early erythroid or T-cell progenitors leads to erythroleukemia or an early block in T-cell differentiation, respectively. While PU.1 function in hematopoietic differentiation is well characterized, the regulation of the PU.1 gene is still poorly understood. We previously identified a -14 kb upstream regulatory element (URE) in the PU.1 gene. Replacement of this element with a neomycin cassette led to mice with hypomorphic PU.1 alleles, and uncovered a dosage effect of this lineage specific transcription factor in acute myeloid leukemia. However, since insertion of a neomycin gene might interfere with PU.1 expression, it was excised from the genome to eliminate any effects other than deletion of the URE. We found that UREΔ/Δ animals exhibited markedly decreased PU.1 expression in multiple lineages, resulting in a profound reduction in macrophage and B-cell numbers in bone marrow and spleen. Thus, normal PU.1 levels are required for development of both lineages in vivo. Furthermore, UREΔ/Δ animals exhibited decreased thymocyte numbers due to a partial block in double negative T-cell differentiation at the transition from DN1/2 to DN3/4 cells. Within a period of 3 to 8 months, many animals developed aggressive, clonal, lymphoblastic T-cell lymphomas, which were dominant over the myeloid leukemia in this model. Gene profiling analysis of early thymocyte populations sorted from preleukemic mice revealed several key genes known to be involved in normal T-cell development and transformation. The role of these novel PU.1 downstream targets is currently being analyzed and the data will be presented. Together, this murine model demonstrates (1) a crucial function of the URE for endogenous PU.1 expression, and (2) a PU.1 dosage effect in the induction of fatal T-cell malignancies. These results show that deletion of a key regulatory element can be a sufficient event for malignant transformation, thus highlighting the need to increase the search for such elements in tumor suppressor genes and proto-oncogenes and to validate their contribution to human disease.
PPARγ Regulates the Anti-Inflammatory Effects of Carbon Monoxide on Macrophages: A Gene Profiling Study.
Authors: Bilban Martin , Otterbein Sherrie L. , Ifedigbo Emeka , Enjyoji Keiji , Usheva Anny , Robson Simon C. , Bach Fritz H. , Otterbein Leo E. , Wagner Oswald 
Published: October 2019

Abstract
Carbon monoxide (CO) at low concentrations has generated recent interest due to its ability to modulate the inflammatory response associated with chronic graft rejection, vascular injury and septic shock. Both in vivo and in vitro CO can inhibit the expression of pro-inflammatory genes such as TNFα in macrophages while simultaneously increasing the expression of the anti-inflammatory cytokine IL-10. The mechanisms by which this occurs are still unclear. To better understand the mechanisms underlying the effects of CO, we employed the Affymetrix GeneChip technology to evaluate the time-dependent expression patterns of >12,000 genes in macrophages stimulated with bacterial endotoxin (LPS) in the presence or absence of a low concentration of CO previously demonstrated to evoke an anti-inflammatory response. We were particularly interested whether CO would, by itself, modulate in a specific manner the expression of proteins that might explain the anti-inflammatory effects observed following subsequent administration of endotoxin. RAW 264.7 murine macrophages were grown to 75% confluency and then exposed to CO (250 ppm) for 3 hr prior to administration of LPS (10 ng/ml). At 0, 15, 30, 60, 120 and 240 min thereafter, total RNA was isolated by standard methods and the RNA was then labeled and hybridized to U74Av2 GeneChips. Of >12,000 genes assessed, 116 of 270 that were LPS-responsive were affected by CO treatment. CO inhibited the majority of LPS-induced pro-inflammatory cytokines and acute phase proteins including expression of early growth response-1 (Egr-1), a transcription factor that serves as a central intermediary regulating many genes. Egr-1 was nearly completely inhibited by CO as was Egr-1-dependent expression of tissue factor (TF) and PAI-1. Treatment of cells with CO alone led to a rapid early increase in PPARγ, the expression of which was essential for the anti-inflammatory effects of CO. Inhibition of PPARγ using the selective chemical inhibitor GW9662 reversed the CO inhibitory effects on LPS-induced Egr-1 and TF expression. Correlative in vivo experiments in mice showed that CO pre-treatment blocked endotoxin-induced Egr-1 expression and decreased markers of lung inflammmation the effects of which were also lost with inhibition of PPARγ. Our analyses of gene expression patterns has led to the first molecular understanding of how treatment with CO, in this case by inducing PPARγ, blocks the pro-inflammatory response. These experiments provide novel insights into the mechanisms and pathophysiology of endotoxic shock and identify cellular targets by which CO mediates these cytoprotective effects.
A Phase I Trial of Dose Escalating Simvastatin Combined with Chemotherapy in End-Stage Myeloma and Lymphoma.
Authors: Lokhorst Henk M. , van de Donk Niels , van de Spek Ellen , de Weerdt Okke , van de Griend Rene , Wittebol Shulamiet , Verdonck Leo F. , Bloem Andries C. 
Published: October 2019

Abstract
We recently described that simvastatin effectively induced apoptosis in myeloma and lymphoma tumor cells by inhibition of proteingeranylgeranylation resulting in the reduction of the anti-apoptosis protein Mcl-1. In addition low concentrations of simvastatin had a chemosensitizing effect in combination with dexamethasone or doxorubicin. Based on these observations we initiated a Phase I study of dose escalating simvastatin combined with chemotherapy in patients with end-stage Myeloma and Lymphoma. Starting dose level of simvastatin was 5 mg/kg/day for 7 days, divided in 2 doses orally, followed by VAD chemotherapy in patients with myeloma and CHOP in patients with lymphoma. Three patients were included per dose level. In the absence of side effects WHO grade III/IV in 3 patients the dose of simvastatin was escalated with 2.5 mg/kg. Twenty-one heavily pretreated patients all refractory to at least 3 lines of chemotherapy (14 myeloma patients and 7 lymphoma patients) were included. No toxicity beyond WHO 2 was recorded with dose level 1–4 (5 mg–12.5mg/kg/day/7days). One patient treated at dose level 5 (15 mg simva/kg/day/7 days) became severely depressed and performed an unsuccessful suicide attempt. Two patients treated at dose level 6 (17.5 mg/kg/day/7 days had severe gastro-intestinal side effects (WHO 3; vomiting, diarrhoea, dehydration), necessitating interrupting simvastatin after 3 and 4 day respectively. The third patient treated at dose level 6 had moderate gastro-intestinal complaints but died on day 13 (2 days after VAD, deeply neutropenic) from overwhelming Gram-Septicaemia although prophylactic antibiotics had been prescribed. Three additional patients were then treated at dose level 5 again without side effects beyond WHO 2. None of the patients complained about muscle pain. No signs of rhabdomyolysis were registered.
Although response was not the primary endpoint of the study, it could be evaluated in 16 patients who completed at least 2 cycles of simvastatin with chemotherapy. Six patients (4 myeloma and 1 transformed low grade lymphoma) responded (32 %) including 5 patients with a Partial Response (> 50 tumor reduction) and 1 patient with a minor response. Four of 8 evaluable (myeloma) patients treated at dose level 4 and 5 responded. Due to toxicity all 3 patients at dose level 6 were not evaluable for response. In patients treated at dose level 4 and 5, in vivo down regulation of Mcl-1 (> 50 %) was observed in PBMC collected after 7 days of simvastatin treatment. These data show that in vivo downregulation of Mcl-1 by high dose (simva) statin in combination with chemotherpy may be a promising new modality for patients with drug resistant myeloma and lymphoma.
VAD-t (Vincristine, Adriamycin, Dexamethasone and Low-Dose Thalidomide) Is an Effective Initial Therapy with High Response Rates for Patients with Treatment Naïve Multiple Myeloma (MM).
Authors: Chanan-Khan Asher Alban , Miller Kena C. , McCarthy Philip , Koryzna Alexandra , Kouides Peter , Donohue Kathleen , Mohr Alice , Bernstein Zale P. , Alam Arif , Czuczman Myron S. 
Published: October 2019

Abstract
Recent understanding of MM biology suggests that MM cells rely on their microenvironment for disease progression and dissemination. MM cell interaction with stromal cells in the bone marrow microenvironment fosters chemotherapy resistance. Targeting the microenvironment with novel biologic agents such as thalidomide (T) has shown encouraging clinical results in patients with previously untreated as well as relapsed/refractory MM. We have previously shown here that VAD plus low dose T (t) is an effective salvage regimen for VAD refractory pts. We report the preliminary results of an ongoing phase II trial studying a combined chemoimmunotherapeutic approach - standard VAD plus t (200 mg) in treatment-naïve MM pts. This regimen was designed to target concurrently the malignant cell and its microenvironment. MM pts, ≥ Stage I with no prior therapy were eligible for study. Monthly infusional VAD (standard dose) was given for 4 cycles every 28 days concurrently with t for 4 months. t (100mg) was started 1 wk prior to VAD and was escalated in 1–2 wks to 200mg. Pts were evaluated for response after each cycle and after cycle 4 using SWOG criteria. Pts characteristics include: enrolled n=16, 8M, 8F; median age 58 yrs range 46–77; Stage III disease n=11, Stage II, n=3 and Stage 1, n=1; and Median B2M, 1.9 mg/L (range 1.2–11.5). Low dose coumadin (1–2 mg) was used for venous thromboembolism (VTE) prophylaxis, t was also held during the 4 days of each infusion of VAD. All pts are evaluable for toxicity and 11 are evaluable for response after completing 4 cyc. 10/11 (91%) responded clinically; CR, n=3, PR, n=7. One pt had progressive disease. Three pts with responding disease were removed from study for Grade III toxicity (1 adriamycin associated cardiomyopathy, 1 pulmonary hypertension and 1 recurrent infections) but are not included in response evaluation. Toxicities: fatigue (Gr. II) was the most common side effect (25%) and DVT was noted in 2 (12%). All pts eligible for stem cell (SC) transplant (n=7), were able to collect adequate amount of SC post VAD-t. Preliminary results of this study suggest that VAD-t is an effective and well-tolerated regimen with improved ORR compared to standard VAD regimen in pts with treatment naïve MM. No increase in incidence of VTE was noted with the combination. Adequate SC collection was achieved in transplant eligible pts. Accrual is ongoing on this study and updated results will be presented at the annual meeting.
Use of Patient-Reported Outcomes (PROs) to Assess Prognosis, Toxicity, and Response: The Bortezomib Experience in Relapsed and Refractory Multiple Myeloma (MM).
Authors: Dubois Dominique , Ravinder Dhawan , van de Velde Helgi , Esseltine Dixie , Gupta Sanjay , Viala Muriel , de la Loge Christine 
Published: October 2019

Abstract
PROs provide patients’ own appraisal of their health status and can be used to measure aspects of health that are generally not captured by ‘traditional’ clinical measures such as physician assessments and test results. This study analyzed PRO data from a multicenter, pivotal phase II trial of bortezomib in 202 patients (pts) with relapsed, refractory MM (NEJM2003;348:2609–17). PRO questionnaires (EORTC-QLQ C30 and MY24, FACT/GOG-Neurotoxicity (Ntx) and FACIT-Fatigue subscales) were administered at the screening visit (baseline) and day 1 of cycles 3, 5, 7 and at the end of the study.
Results: In this population with relapsed, refractory MM, poorer baseline pre-treatment multi-dimensional quality of life (QoL) scores were significantly correlated (range of r= 0.22 to r= 0.77) with fatigue, pain, dyspnea, appetite loss, neurotoxicity, MM disease symptoms, and treatment side effects. Clinical response to bortezomib (Complete Response or Partial Response) was associated with statistically significant (p<0.05) improvements in global QoL, physical, emotional and social functioning, fatigue, dyspnea, constipation, disease symptoms, social support and future perspective, whereas pts with a minimal response, no change or disease progression usually reported stable or worsening scores. Despite concern about peripheral neuropathy (12% for grade 3), FACT/GOG-Ntx change scores were stable in all responder groups. The prognostic value of baseline PRO data relative to clinical information was assessed using Partial Least Square (PLS) regression. First a model predicting death during the study (17 patients died during the study out of 202; 8.42%) identified that at baseline high total serum protein, bone marrow plasma cells and ß2-microglobulin and low platelet count, serum albumin, hemoglobin, Karnofsky score, body surface area and weight were predictive of death. In a separate model, the following baseline PRO scores predicted death during the study: high fatigue, appetite loss, treatment side effects, sleep disturbance, dyspnea and pain scores and low FACIT-Fatigue, physical, role, social, global QoL, cognitive, emotional and FACT/GOG-Ntx scores. The combination of the clinical and PRO PLS components into a hierarchical PLS regression resulted in an increase in the predictive value of the model, suggesting complementary information.
Conclusion: PRO data can serve as independent measures of clinical benefit, toxicity, and even mortality risk, complementing traditional physician assessments and test results. In this trial of relapsed and refractory MM pts, PRO results suggested improvements in QoL for clinical responders, tolerable side effects, and independent prognostic value for mortality.
MALT1 Is an Essential Regulator of Antigen Receptor Mediated NF-kappaB Activation.
Authors: Ruland Jürgen , Mak Tak 
Published: October 2019

Abstract
The translocation t(11;18)(q21;q21) is the most common chromosomal abnormality in lymphomas of mucosa associated lymphoid tissue (MALT lymphoma). Molecular cloning of the breakpoint demonstrated that t(11;18) leads to the fusion of the IAP2 gene to the novel gene MALT1. MALT1 encodes a paracaspase that can bind to BCL10 but its cellular function was unknown. We have previously demonstrated that BCL10, which is involved in independent MALT lymphoma translocations, functions as a positive regulator of lymphocyte proliferation. BCL10 connects antigen receptor signaling in B and T cells to NF-kappa B activation. To identify the physiological role of MALT1 we have now disrupted the MALT1 gene in mice. Here we are using both MALT1 and BCL10 deficient animals and show that MALT1 is essential for functional T cell activation, proliferation and cytokine production in response to T cell receptor (TCR) ligation. Similar to BCL10 we found MALT1 to be strictly required for signal-specific NF-kappaB activation in response to TCR ligation but not for TNF-alpha or IL-1 signaling. MALT1 operates downstream of BCL10, controls the catalytic activity of IKK and additionally regulates signaling of p38 and JNK MAP kinases. Moreover we found MALT1 to be critical for B1 and marginal zone (MZ) B cell development. In contrast to BCL10 disruption however, inactivation of MALT1 has only mild effects on conventional B2 B cell activation, BCR induced NF-kappaB signaling in splenic B lymphocytes and does not cause defects during embryonic development. Thus, MALT1 is an essential regulator of BCL10 mediated NF-kB induction that is differentially required depending on the cellular context. Together these data support the view that normal expression of BCL10 and MALT1 are necessary for controlled NF-kB signaling in lymphocytes whereas deregulation of either BCL10 or MALT1 through chromosomal translocation results in increased lymphocyte growth and survival
Global Assessment of Promoter Methylation in a Murine Model of Cancer Identifies ID4 as a Putative Novel Tumor Suppressor Gene in Human Leukemia.
Authors: Yu Li , Liu Chunhui , Vandeusen Jeff , Becknell Brian , Dai Zunyan , Wu Yue-Zhong , Raval Aparna , Liu Te-Hui , Ding Wei , Mao Charlene , Liu Shujun , Smith Laura T. , Lee Stephen , Rassenti Laura , Marcucci Guido , Byrd John , Caligiuri Michael A. , Plass Christoph 
Published: October 2019

Abstract
We developed a mouse model of acute T/natural killer (NK) acute lymphoblastic leukemia (ALL) that is always preceded by polyclonal lymphocyte expansion to determine how aberrant promoter DNA methylation and consequent gene silencing might be contributing to leukemic transformation. We demonstrated the non-random nature of methylation in the transformation from benign polyclonal expansion to leukemia, and identified a novel tumor suppressor gene silenced in the majority of human leukemia but not solid tumors. To this, we utilized restriction landmark genomic scanning (RLGS) on eight IL-15 transgenic (tg) mice with T/NK ALL, and performed RLGS on an additional five spleens from IL-15tg mice without ALL, but with polyclonal T/NK expansion, and on four spleens from wild type (wt) mice. A total of 2447 RLGS fragments with good resolution on each RLGS profile were analyzed. Only 1–2 variable changes were detected in either wt or polyclonal T/NK expansion controls. In contrast, the eight spleens with clonal T/NK leukemia had 45 to 209 changes (1.8 to 8.5% of total fragments) consistent with aberrant DNA methylation. The association of RLGS fragment losses or reduced intensity with leukemic transformation versus polyclonal expansion was highly significant (P<0.001). The promoter of Inhibitor of DNA binding 4 (Id4) was found methylated in 87.5% of the mouse T/NK ALLs. ID4 was found methylated in 85.7% (72/84) of primary human acute myeloid leukemias (AML) and in 100% (61/61) of chronic lymphocytic leukemias (CLL). Id4 was silenced secondary to promoter methylation in 100% mouse T/NK ALLs (n=5) and human acute leukemias (n=6). Overexpression of Id4 induced apoptosis in mouse cell line YAC-1 and inhibited tumor growth both in vitro and in vivo. These data, and an analysis of 219 RLGS profiles from different types of human tumors demonstrate that the ID4 promoter is preferentially methylated and functions as a putative novel tumor suppressor gene in mouse and human leukemia. This study highlights the use of a novel animal model, novel mouse NotI-EcoRV arrayed library, and RLGS to examine the role of methylation in leukemic transformation and to identify new targets for prevention and therapeutic strategies.
Aberrantly Hypermethylated Genes in Adult T-Cell Leukemia Cells: The Implications in the Leukemogenesis.
Authors: Yasunaga Jun-ichirou , Taniguchi Yuko , Nosaka Kisato , Satou Yorifumi , Yoshida Mlka , Takai Ken , Sakai Tatsunori , Mitsuya Hiroaki , Matsuoka Masao 
Published: October 2019

Abstract
Adult T-cell leukemia (ATL) is a highly aggressive neoplasm of helper T lymphocytes and is etiologically associated with human T-cell leukemia virus type I (HTLV-I). Although HTLV-I encoded Tax protein is thought to play a central role in the leukemogenesis of ATL, ATL cells frequently could not produce Tax protein by the somatic mutations, deletion and loss of 5′-LTR. Moreover, a long-term latent period (almost 60 years in Japan) precedes the onset of ATL, suggesting that multistep tumorigenesis is involved in development of ATL in addition to role of viral protein. Such transformation process is thought to include alterations of host genome: genetic and epigenetic changes. The epigenetic alteration, such as DNA methylation and histone modification, is commonly observed in various cancer cells. Recently, we reported that the aberrant expression of MEL1S gene, which is hypomethylated in ATL cells, confers resistance against transforming growth factor-beta.
In this study, we identified 53 aberrantly hypermethylated DNA sequences in ATL cells using methylated CpG island amplification/representational difference analysis (MCA/RDA) method. In addition, we found that the DNA methylation of these regions tends to accumulate with disease progression. Seven genes, which were expressed in normal T-cells, but suppressed in ATL cells, were identified near the hypermethylated regions. Among these silenced genes, Kruppel-like factor 4 (KLF4) gene is a cell cycle regulator and early growth response 3 (EGR3) gene is a critical transcriptional factor for induction of Fas ligand (FasL) expression. Treatment with 5-aza-2′-deoxycytidine resulted in the recovery of their transcription, indicating that their silencing is associated with DNA hypermethylation. To study their role in oncogenesis of ATL, we transfected recombinant adenovirus vectors expressing KLF4 and EGR3 genes into ATL cell lines. Expression of KLF4 induced apoptosis of ATL cells whereas enforced expression of EGR3 induced the expression of FasL gene, resulting in apoptosis. This EGR3-induced apoptosis has been inhibited by stable transfection of cellular and viral FLIP, which suppress the activation of caspase-8 by preventing pro-caspase-8 in Fas-mediated apoptosis pathway. Therefore, suppressed expression of EGR3 enabled ATL cells to escape from activation-induced cell death mediated by Fas-FasL signaling. Our results showed that the DNA hypermethylation plays an important role in the leukemogenesis of ATL by silencing transcriptions of genes that inhibit the abnormal growth of ATL cells.
Loss of the INK4A Locus Accelerates tal1/scl-Induced Leukemia in Mice.
Authors: Calvo Jennifer A. , Kelliher Michelle 
Published: October 2019

Abstract
Tal1/scl, a basic helix-loop-helix (bHLH) transcription factor essential for hematopoiesis and vasculogenesis, is also found misexpressed in patients with T cell acute lymphoblastic leukemia (T-ALL). In our mouse model of tal1/scl-induced disease, mice develop T cell leukemia after a long latency, suggesting that additional mutations are required for leukemogenesis. In T-ALL patients, the INK4a locus, which encodes both p14ARF and p16INK4a, is often found mutated or methylated, suggesting that loss of p16INK4A/p14ARF expression contributes to the development of T-ALL. Similarly, we fail to detect p16INK4A/p19ARF expression in our mouse tal1/scl leukemic cells. To determine if the loss of INK4a cooperates with tal1/scl to induce leukemia, we mated our tal1/scl transgenic mice to INK4a −/− mice to generate a cohort of tal1/scl/INK4a+/− mice. Mice heterozygous for INK4a are healthy and are not predisposed to the development of leukemia. In contrast, tal1/scl/INK4a+/− mice develop T cell leukemia at an accelerated rate, within a median survival period of 110 days, compared to a median survival of 352 days for the tal1/scl transgenic mice, which are wild type with respect to INK4a. Taken together, these data suggest that mutation of the INK4a locus contributes to tal1/scl-mediated leukemogenesis in mice, similar to the widespread deletion of the INK4a/ARF locus observed in TAL1/SCL-expressing human leukemia (Ferrando, 2002). BrdU labeling of preleukemic tal1/scl thymocytes reveals a 41% increase in the percentage of thymocytes in S phase of the cell cycle, suggesting that tal1/scl may stimulate cell cycle progression. In contrast to wild type thymocytes which exhibit 14.5% (±1.5) of cells in S phase, 24.5% (± 2.9) of preleukemic tal1/scl thymocytes are found in S phase (p<0.05, n=4). Moreover, an increase in the sub-G1 population is also observed in the tal1/scl preleukemic thymus. Preliminary cell cycle analysis of tal1/scl/INK4a−/− thymocytes reveals a decrease in the sub-G1 population, suggesting that the absence of the INK4a locus may contribute to tal1/scl leukemogenesis, in part, by inhibiting the tal1/scl-induced apoptosis.