bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epigenetic Repression of the Adaptor Molecule LAT2 by the Leukemic Fusion Protein AML1/ETO.
Authors: Duque-Afonso Jesus , Berg Tobias , Heidenreich Olaf , Luebbert Michael 
Published: October 2019

Abstract
The chromosomal translocation (8;21) fuses the hematopoietic transcription factor AML1 (RUNX1) with ETO, resulting in the leukemia-specific chimeric protein AML1/ETO. This fusion protein represses transcription by recruiting a nuclear co-repressor complex containing HDACs and DNMT1 to its target promoters. Previously, we have identified a novel in vivo AML1/ETO target gene, LAT2 (NTAL/LAB/WBSCR5), which is involved in FcεR I, c-Kit, B cell- and T cell receptor signalling. Notably, LAT2 is strongly repressed in AML1/ETO positive cells including primary AML blasts, which was confirmed by others in several large AML cohorts. We have now addressed the molecular mechanisms of AML1/ETO-mediated LAT2 repression. AML1/ETO was induced by Ponasterone A in an ecdysone-inducible system in U937 cells (9/14/18 cell line). To deplete AML1/ETO in t(8;21)-positive cells, we electroporated Kasumi-1 cells with AML1/ETO siRNA. To interfere with epigenetic modifications more directly, cells were treated with the DNMT inhibitor decitabine (DAC) and 4 different HDAC inhibitors. LAT2 expression was determined by Northern Blot, qRT-PCR and Western Blot. HDAC occupation and the histone status of the LAT2 promoter was examined by chromatin immunoprecipitation (ChIP). LAT2 mRNA was downregulated already after 4 hours of conditional expression of AML1/ETO in 9/14/18 cells, and constitutively repressed in the AML1/ETO-positive Kasumi-1 and SKNO-1 cells. siRNA-mediated AML1/ETO depletion caused a 9-fold upregulation of LAT2 in Kasumi-1 cells, suggesting a possible direct mechanism of repression. To address this question, we performed ChIP assays for the LAT2 promoter after AML1/ETO induction in 9/14/18 cells. AML1/ETO inhibited acetylation of histone H3, H3K9 and H4, but did not affect trimethylation of H3K4. These changes were associated with the recruitment of HDAC2, but not HDAC1 and HDAC3, to the LAT2 promoter. The HDAC inhibitors MS-275, SAHA, TSA and valproic acid induced LAT2 mRNA in a dose-dependent manner in AML1/ETO-expressing Kasumi-1, with MS-275 being the most efficient inhibitor. MS-275 induced LAT2 expression also in t(8;21)-positive SKNO-1, but not in AML1/ETO-negative HL60 and U937 cells. LAT2 mRNA was also upregulated in a dose-dependent manner after DAC treatment in Kasumi-1 cells. The combination of DAC and MS-275 had a synergistic effect on inhibition of cell growth, acetylation of histones H3 and H4, and re-expression of LAT2 mRNA. MS-275-mediated re-expression of LAT2 was associated with an increase in acetylation of histone H3, H3K9, H4 and trimethylation of H3K4. The increase of activating histone modifications was associated with the release of HDAC1, HDAC2 and HDAC3 from the LAT2 promoter. In conclusion, the epigenetic changes of the LAT2 promoter caused by AML1/ETO could be pharmacologically reverted by inhibition of histone acetylation.
Genetic and Clinical Spectrum of Osteopetrosis.
Authors: Schulz Ansgar S , Moshous Despina , Debatin Klaus-Michael , Villa Anna 
Published: October 2019

Abstract
Abstract 1087
Poster Board I-109

Background
Osteopetrosis (OP) is a multi-systemic inborn disorder characterized by heterogeneous clinical presentations on the basis of a variety of mutated genes. We performed a retrospective analysis in patients with OP from 28 European centers on behalf of the ESID and the EBMT. Main objectives of this analysis were survival and quality of life with respect to genetic background, initial clinical presentation, and treatment modality.

Methods
A set of clinical parameters, genetic findings, transplant information and follow up data were collected using specific questionnaires. Questionnaires were sent at several time points to European centers treating patients with OP and the collected data were stored in a central OP database. DNA sequencing of candidate genes involved in human OP was done predominantly at laboratories in Milan, Paris and Ulm.

Results
Data of 173 patients and of 134 hematopoietic stem cell transplantations (HSCT) were obtained during a time frame between 1983 and 2008. In the whole cohort, mutations in the following genes were detected: 47% biallelic TCIRG1, 9% biallelic CLCN7, 6% monoallelic CLCN7, 5% OSTM1, 2% RANK, 1% RANKL; 30% of patients have no mutations in these genes or could not be tested completely. In 23% of patients HSCT was not considered because of severe neurological problems or other complications mostly in the context of OSTM1 or CLCN7 mutations, or because of less severe phenotypes mainly due to monoallelic CLCN7 mutations (autosomal dominant OP, ADO).
Follow up data of 103 transplanted patients were available. With respect to donor type, the probability of survival at 2 years was 88% for matched family donors, 80% for matched unrelated donors, 68% for HLA-haploidentical donors and 54% for mismatched unrelated donors. There was no significant difference in survival of patients with different gene mutations but a trend to a worse long term outcome in CLCN7 patients. Most notably, several major sequelae were present in the majority of surviving patients. Visual impairment or dwarfism were found in about 2/3 of children showing no significant influence of the affected genes. About 10% of patients are suffering from significant persistent neurological problems after HSCT, which were found in patients with TCIRG and CLCN7 mutations. The quality of life were judged as normal by the parents in about 2/3 of surviving patients.

Conclusion
HSCT in infantile OP results in acceptable survival rates even after HLA-nonidentical transplants. However, outcome is influenced by a set of specific disease related problems and long term sequelae. The heterogeneity of OP necessitates an individualised therapeutic strategy respecting the genetic background, the clinical presentation and the type of the available donor.

Disclosures
No relevant conflicts of interest to declare.
Second Autologous Stem Cell Transplant (ASCT) as Salvage Therapy in Patients with Relapsed Multiple Myeloma.
Authors: Mikhael Joseph R. , Zadeh Sahar , Stewart A. Keith , Chen Christine , Trudel Suzanne , Kukreti Vishal , Winter Andrew , Franke Norman , Reece Donna E. 
Published: October 2019

Abstract
Abstract 1217
Poster Board I-239

Background
Single autologous stem cell transplant (ASCT) is considered the standard of care after induction therapy for younger multiple myeloma (MM) patients (pts). However, it is not curative and virtually all patients will ultimately relapse. As more options are available to treat relapsed disease, the role of a second ASCT as salvage therapy is unclear.

Method
Retrospective review of all MM pts who received a 2nd ASCT as salvage therapy at Princess Margaret Hospital.

Results
Between February 1997 and July 2009, 79 MM pts received a second ASCT for relapsed MM at our institution. Median age was 60 yrs (range 39-72) at second transplant. 48 pts (61%) were male. Immunoglobulin subtype included IgG (42), IgA (21), light chain (11), nonsecretory (3), IgM(1) and IgD (1). Transplant conditioning regimen for first transplant was high dose melphalan (MEL) 140-200 mg/m2 in 67, busulphan and cyclophosphamide in 1, and combinations of MEL with etoposide (E) or TBI in the rest. 2nd ASCT conditioning consisted of MEL alone in 76, the remaining 3 had MEL with either TBI or E. The median time to relapse after the first transplant was 2.72 years (0.81-8.26), with a median interval between transplants of 3.61 years (1.63-9.59). Response to first transplant in 78 evaluable patients was 13 CR/nCR (17%), 56 PR/VGPR (72%), 9 MR/SD (12%). Nineteen pts received maintenance therapy between transplants. Two transplant-related deaths occurred following 2nd ASCT. In 73 evaluable patients, response to second transplant was 11 CR/nCR (15%), 57 PR (78%), 6 MR/SD (8%). After 2nd ASCT, with median follow up 5.92 years (71 months), median progression-free survival (PFS) was 18.5 months and median overall survival (OS) was 4.4 years. Long term progression-free status based on the progression-free interval after 1st ASCT is summarized Table 1. PFS based on progression free interval after 1st ASCT is outlined in Figure 1.

Conclusions
2nd ASCT is a feasible and safe salvage therapy in relapsed MM patients. It is effective in providing a median progression free survival of 18.5 months and median overall survival of 4.4 years (52.8 months) after 2nd ASCT. This is comparable if not better than modern salvage chemotherapies. The longer the disease free interval after 1st ASCT the more effective 2nd ASCT is at extending both progression free survival and overall survival. It is reasonable, therefore, to consider a 2nd ASCT if the time to progression is greater than 2 years after first ASCT.

Disclosures
Chen: Celgene: Honoraria, Research Funding; Ortho Biotech: Honoraria. Trudel:Celgene: Honoraria, Speakers Bureau; Ortho Biotech: Honoraria. Kukreti:Celgene: Honoraria.
Improved Survival for Patients Undergoing Autologous Stem Cell Transplant for Primary CNS Lymphoma in First or Later Remission.
Authors: Johnston Patrick B , Micallef Ivana N , Ansell Stephen M , Inwards David J , Porrata Luis F. , O'Neill Brian Patrick 
Published: October 2019

Abstract
Abstract 1222
Poster Board I-244

Background
Survival for patients with primary CNS lymphoma (PCNSL), in general, is poor with patients requiring frequent chemotherapy treatments or receiving whole-brain radiation therapy, which can potentially result in significant neurologic decline and dementia. Because of the improved survival of high risk patients with aggressive lymphoma undergoing autologous stem cell transplant (ASCT), we began ASCT for patients with PCNSL in first or later remission with chemotherapy sensitive disease. We now update on outcomes of patients who have had at least 100 day follow up post ASCT.

Baseline characteristics
Between June, 2000 and January, 2009, 22 patients underwent ASCT for PCNSL. Median age at transplant was 50 years old (range 26-67). Median number of prior treatments 1 (range 1-3). Median time from diagnosis to transplant was 7.2 months (range 2.9 to 75.8). Median International Extranodal Working Study Group Prognostic Score: 2 (range 0-3). Disease status at transplant: First CR 10 patients, later CR or PR 12 patients.

Results
Twenty-two patients underwent ASCT for PCNSL and have a minimum of 100 days follow-up. All patients received BEAM conditioning. Median follow up post-transplant was 30 months (range 3-107 months). Eight patients have relapsed at a median of 217 days (range 40-1349). Of the patients who relapsed, four have died of disease progression and the remaining four are alive after additional therapy. Median overall survival from diagnosis or transplant has not been reached. Median progression free survival from transplant was 70 months.

Conclusions
Although limited by patient selection and retrospective biases, this review suggests that ASCT for PCNSL demonstrates improved overall survival when compared to historical controls with similar PCNSL Prognostic Scores (2 year survival for patients from diagnosis with PS 2-3 was 48% in a prior published study). ASCT in first remission in patients with PCNSL appears promising and may limit the need for additional therapy which can be myelosuppressive or result in neurologic decline secondary to radiation therapy in patients who are appropriate candidates.

Disclosures
No relevant conflicts of interest to declare.
The First Human Cell Line Recombinant Factor VIII (Human-cl rhFVIII) - Functional Properties and Differences From Currently Available Recombinant Factor VIII Products.
Authors: Schwartz Bruce A. , Sandberg Helena , Agerkvist Irene , Kannicht Christoph , Ramström Margareta , Stenlund Peter , Oswaldsson Ulla , Brunberg Tobias 
Published: October 2019

Abstract
Abstract 1298
Poster Board I-320
All current recombinant factor VIII products produced today are derived from the expression of FVIII in hamster cell lines. This is a report of the functional properties of a newly developed recombinant factor VIII concentrate produced in a human cell line. The possible advantage of using a human cell line for expression of recombinant factor VIII is that a human pattern of post-translational modifications (PTM), such as glycosylation, are obtained. These human like PTMs, may possibly lead to improved function and a reduced immunogenic product profile compared to recombinant factor VIII products from CHO or BHK cells that have hamster-specific PTM. Data are presented on the characteristics of the Human-cl rhFVIII, a B-domain-deleted factor VIII protein produced in HEK293F cells, and how they compare with those of other factor VIII products.
Human-cl rhFVIII is highly pure (>99.9% purity) with a high specific activity of 8000-11000 IU/mg protein, and a FVIII:C to FVIII:Ag ratio close to 1.0. This indicates that the entire factor VIII protein in the product is active. Human-cl rhFVIII showed no significant assay discrepancy between one-stage and chromogenic assay results. Because of the human glycosylation profile of the new Human-cl rhFVIII, there was an absence of the antigenic type of sialic acid, N-glycolylneuraminic acid as well as of antigenic Galα (1,3) Gal epitopes found in the non humane derived products. Another type of PTM of factor VIII is the sulfation of certain tyrosines that are crucial for the biological function e.g. the interaction with von Willebrand factor (vWF). Human-cl rhFVIII was found to be optimally sulfated when compared to endogenous human FVIII. In this context, it is of interest to note that Human cl-rhFVIII showed a 60% higher affinity in binding to vWF compared to other recombinant factor VIII products and the number of molecules in the product able to bind to vWF was significantly higher for Human-cl rhFVIII.
Interaction with thrombin and capacity to generate thrombin were shown to be similar to those of plasma-derived factor VIII. The sensitivity to be inactivated by activated protein C was similar to all currently licensed rhFVIII products. The important properties of Human cell line derived recombinant factor VIII may be very promising for its use in future treatment of Haemophilia A.

Disclosures
Schwartz: Octapharma: Employment. Sandberg:Octapharma: Employment. Agerkvist:Octapharma: Employment. Kannicht:Octapharma: Employment. Ramström:Octapharma: Employment. Stenlund:Octapharma: Employment. Oswaldsson:Octapharma: Employment. Brunberg:Octapharma: Employment.
Survival Among Leukemia Patients Over the Past Three Decades: A Single Institution Based Retrospective Review From 1976 to 2006.
Authors: Sheikh Hassan S , Joshi Monika , Camacho Fabian , Hand Lisa A , Bayerl Michael G. , Rybka Witold B 
Published: October 2019

Abstract
Abstract 1394
Poster Board I-416

Background:
Leukemia is the fifth most common cause of cancer death in men and seventh most common cause in women in the US. Since the advent of multi-drug chemotherapy, studies have shown improvement in survival for specific age groups. However, there have been few studies showing the impact of evolving therapies on survival for the total burden of leukemia patients. We assessed survival for an aggregate population of all patients presenting with leukemia to a regional tertiary university hospital over the past 3 decades.

Goal:
To assess the magnitude of improvement in survival for patients with leukemia over the past 3 decades.

Methods:
We analyzed data from the Penn State Hershey Medical Center Cancer Registry, selecting all cases diagnosed with leukemia by ICD-0-3 codes, excluding chronic lymphocytic leukemia, from Jan 1st 1976 to Dec 31st 2006. Five and ten year (yr) absolute survival rates during five time periods [group (gp) 1: 1976-1980, gp 2: 1981-1985, gp 3: 1986-1990, gp 4: 1996-2000, gp 5: 2001-2006] were obtained using conventional period analysis (PA). In addition, a period Cox Proportional Model (CPH) was fit to the data, allowing for survival risk estimates of 5 yr survival, statistical testing of time periods, and adjustments for age at diagnosis. SAS v 9.1 was used to obtain estimates, with Brenner's PERIOD macro used for PA and PHREG used for CPH.

Results:
Of 1892 patients, chronic myeloid leukemia (CML) accounted for 11%, acute myeloid leukemia (AML) 52% and acute lymphoblastic leukemia (ALL) 37%. Median age was 44 yr and mean was 40 yr with a standard deviation (SD) of 27.2 yr. Median follow up was 1.6 yr and mean was 3.9 yr with SD 5.1 yr. Approximately 13% (N=249) survived beyond 10 yr. CPH adjusted for age demonstrated an improvement in 5 yr survival among all patients with leukemia of 16%, Hazard Ratio (HR)=1.57, p=0.0002, and 16% in 10 yr survival, HR=1.6, p= 0.0001, between gp 5 and gp 1. Consistent improvements in age adjusted 5 yr survival were detected for CML (24%, HR=2.06, p=0.124), AML (17%, HR=1.53, p<0.0015) and ALL (21%, HR=1.8, p=0.01) comparing gp 5 to gp 1. Results for conventional PA were similar. There was a 19% improvement in 5 yr survival between gp 5 and gp1 for all patients with leukemia. There was greater variability by PA in the subgroups, CML(58% 5 yr), AML (7% 5 yr) and ALL (24% 5 yr).

Conclusion:
Our analysis shows that there is a significant improvement of 16% in overall five and ten year survival rates in all leukemia patients over the last 30 years after adjusting for age at diagnosis. Subgroup analysis shows comparable improvements among the three diagnostic groups.

Disclosures:
No relevant conflicts of interest to declare.
MicroRNA Changes Occur in Multiple Myeloma Cells in the Context of Bone Marrow Milieu.
Authors: Roccaro Roccaro M. , Sacco Antonio , Azab Abdel Kareem , Azab Feda , Ngo Hai , Melhem Molly R , Quong Phong , Runnels Judith M. , Anderson Kenneth C. , Ghobrial Irene 
Published: October 2019

Abstract
Abstract 1785
Poster Board I-811

Background
We and Others have previously demonstrated that primary multiple myeloma (MM) cells are characterized by a specific microRNA (miRNA) signature compared to the related normal plasmacell counterpart; and that miRNAs play a crucial role in regulating MM pathogenesis. Nevertheless, miRNA changes that occur in MM cells in the context of the bone marrow microenvironment have not been previously examined. Therefore, characterization of miRNA profiling of MM cells in conjunction with bone marrow stromal cells (BMSCs) is important to better understand the underlying molecular changes that lead to initiation and progression of this disease.

Methods
We performed miRNA-expression-profiling of MM cell lines (MM.1S; RPMI8226) that were co-cultured with primary BMSCs obtained from 5 MM patients, using liquid phase Luminex microbead miRNA profiling (Luminex, Austin, TX). The expression patterns of unfiltered data were performed using unsupervised hierarchical clustering of samples, based on centroid linkage and 1-correlation distance metric, using dChip (www.dchip.org). To further define those miRNAs differentially expressed between groups (patients vs normal), the data were filtered on significance of differences using ANOVA test, (P < 0.05). Microbead-miRNA profiling data were validated data by stem-loop qRT-PCR. To identify specific predicted miRNA-targeted mRNAs, TargetScan, PicTar, and miRanda algorithms were used.

Results
miRNA profiling of MM cells cultured with primary BMSCs (MM+BMSC system) differs from MM cells which were not grown in contact with primary BMSCs (MM cells alone). Specifically, we observed increased expression of miRNA-450, -432*, -299-5p, -409-3p, -29b, -542-5p, -184, -517*, -218, 128b, -142-5p and -211 (P<0.05) in MM cells obtained from the MM+BMSC system, compared to MM cells alone. Stem-loop qRT-PCR was performed on matched samples and showed expression patterns similar to those observed in miRNA analysis. Using algorithms commonly used to predict human miRNA gene targets (miRanda; TargetScan; PicTar), predicted targets of the increased miRNAs included negative regulators of NFkB, PI3K/Akt/mTOR, and MAPK/ERK signaling pathways, such as PTEN, KSR2, TWEAK, and DUSP; as well as tumor suppressors (MCC, TSSC1, TUSC1, FBW7, RHOBTB), pro-apoptotic factors and cyclin-dependent kinases inhibitors.

These data demonstrate that bone marrow stromal cells exert a modulatory effect on miRNA profiling in MM cells, which results in promoting MM cell growth and reducing MM cell survival.

Disclosures
Ghobrial: Millennium : Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau.
The Combination of Arsenic Trioxide and Interferon-Alpha Eradicates Leukemia Initiating Cells in TAX-Driven Murine Adult T Cell Leukemia/Lymphoma.
Authors: Bazarbachi Ali , Hajj Hiba El , El-Sabban Marwan , Hasegawa Hideki , Zaatari Ghazi , Saab Shahrazad , Janin Anne , Mahfouz Rami , Nasr Rihab , Kfoury Youmna , Nicot Christophe , Hermine Olivier , Hall William , de The Hugues 
Published: October 2019

Abstract
Abstract 2714
Poster Board II-690
Adult T cell leukemia (ATL) is one of the rare human cancers initiated by a transforming retrovirus, HTLV-I. After many years of controversy, it is now accepted that the viral transactivator protein Tax plays a critical role in initiating the leukemic process, because Tax transgenics develop a disease with striking ATL features. Long-term prognosis of ATL patients remains extremely poor, but we recently reported that the combination of As2O3, interferon-a (IFN), and zidovudine yielded unprecedented response rates. Indeed, in 10 chronic ATL patients, a 100% response rate was observed, including 7 complete remissions (CR), 2 CR but with more than 5% circulating atypical lymphocytes, and one partial response. We demonstrate that the As2O3/IFN combination, previously shown to degrade Tax, cures Tax-driven murine ATLs. Unexpectedly, this combination immediately abrogates leukemia transplantation into secondary recipients, while the primary tumor continues to grow and only exhausts much later. Leukemia initiating cell (LIC) clearance is reversed by proteasome inhibition, demonstrating that LICs are addicted to continuous Tax expression. Most anticancer treatments fail to target LIC. These results establish that As2O3/IFN/zidovudine acts through Tax targeting and predict a favorable long-term outcome for responsive patients. Thus, oncogene degradation can selectively target LICs, explaining this very recent success of a similar regimen in patients.

Disclosures:
No relevant conflicts of interest to declare.