bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prolonged Administration of the Telomerase Vaccine GRNVAC1 Is Well Tolerated and Appears to Be Associated with Favorable Outcomes In High-Risk Acute Myeloid Leukemia (AML)
Authors: Khoury H. Jean , Collins Robert H. , Blum William , Maness Lori , Stiff Patrick , Kelsey Stephen M. , Reddy Anita , Smith Jennifer A. , DiPersio John F. 
Published: October 2019

Abstract
Abstract 2190

Background:
Telomerase activity in leukemic blasts is frequently increased in high-risk AML patients, and the major protein catalytic subunit of telomerase (hTERT) includes immunogenic epitopes which can stimulate generation of hTERT-specific cytotoxic T cells.

Methods:
We evaluated the feasibility, safety, and immunologic effects of telomerase catalytic subunit (hTERT)-expressing autologous dendritic cells (DC) in adult AML patients. GRNVAC1 (VAC1) was produced at a central facility from patient-specific leukapheresis harvests. Immature DCs from monocyte-enriched PBMCs were electroporated with an mRNA construct encoding hTERT and a lysosomal targeting sequence (LAMP-1). Further culture with cytokines induced a mature DC phenotype. AML patients were eligible if in CR1 and with intermediate or high risk cytogenetics or in CR2. PBMCs were harvested after induction, and before or after completion of planned consolidation cycles. Patients in ongoing CR or early relapse (<20% marrow blasts) were vaccinated. Vials of VAC1 containing 1 × 107 cells were administered by intra-dermal injections weekly × 6, followed by 4 weeks off, then as boost vaccinations every other week × 6. In cases where additional vials were available, injections could then continue on a q28 day extended boost schedule. This abstract summarizes safety of administering VAC1 up through the extended boost schedule.

Results:
Between September 2007 and December 2009, 33 patients with a median age 61yrs (range, 30–75) were enrolled and leukapheresed. 21 patients received VAC1 vaccinations, 19 in CR (16 in CR1 and 3 in CR2) and 2 in early relapse. Eight of 16 in CR1 were at intermediate risk of relapse and 8 were at high risk of relapse. A median of 17 (6-32) vaccinations were administered to those 19 patients. VAC1 was well tolerated with no toxicities with the exception of one patient who developed ITP after 6 vaccinations. Local transient erythema at the site of injection was common in all patients.
With a median follow-up of 10.5 months (range, 1.2–27.2) months, 4/19 relapsed and 7 continue to receive VAC1. The Kaplan-Meier estimate of disease free survival (DFS) at 12 months, measured from beginning with the first vaccination of VAC1, was 79% for the 19 CR patients (95% CI: 52%-91%), 75% (31%-93%) for the eight patients in the intermediate risk group, and 81% for the 11 patients in the high risk group. Median DFS was not reached.

Conclusions:
Prolonged administration of VAC1, up to 32 vaccinations (the maximum number administered so far), is well tolerated in patients with AML, and associated with favorable DFS, especially in high-risk patients.

Disclosures:
DiPersio: Genzyme: Honoraria.
A Functional Variation In the NKG2D Gene Regulates NKG2D Receptor Expression and Is Associated with Better Transplant Outcomes After Fully-HLA-Matched Unrelated Bone Marrow Transplantation
Authors: Espinoza Luis J. , Takami Akiyoshi , Yoshioka Katsuji , Nakata Katsuya , Nakao Shinji 
Published: October 2019

Abstract
Abstract 221
A functional variation in the NKG2D gene regulates NKG2D receptor expression and is associated with better transplant outcomes after fully-HLA-matched unrelated bone marrow transplantation
NKG2D, an activating receptor expressed by NK cells and some T cells, plays important roles in both immunity to microbial infections and cancer immune surveillance. A single nucleotide polymorphism (SNP rs1049174) in the 3′-untranslated region (3′UTR) of the NKG2D gene determines two genotypes, HNK1 genotype with high NK cytotoxicity, and the LNK1 genotype with low NK cytotoxicity. Individuals with the HNK1 genotype have reduced risk of cancer (Cancer Res 2006; 66(1):63-70). In the present study, we analyzed the impact of SNP rs1049174 on transplant outcomes after HLA-matched unrelated bone marrow transplantation. The NKG2D genotypes were retrospectively analyzed in a cohort of 360 pairs of patients and their unrelated donors transplanted through the Japan Marrow Donor Program. The donor HNK1 genotype was associated with lower transplant related mortality (TRM) in patients with standard risk (hazard ratio [HR], 0.58; 95% confidence interval [CI], 0.35–0.97; P=0.04) (Fig.1). The donor HNK1 genotype was also associated with a trend toward better OS (HR, 0.69; 95% CI, 0.46–1.04; P=0.08). The host NKG2D genotypes did not significantly influence the transplant outcomes. NK cells from HNK1 donors expressed higher levels of NKG2D on the cell surface, and also expressed higher levels of NKG2D mRNA. Luciferase reporter gene constructs transfected into NK cells showed that the LNK1 construct more effectively attenuated gene expression compared with the HNK1 construct (60% vs. 35%). Bioinformatics tools predicted an interaction between the rs1049174 SNP motif with the micro-RNA-1245 (miR1245). Next, in an mRNA/miRNA binding assay, the LNK allele showed higher affinity to the miR1245 than the HNK1 allele. Moreover transfection of NK cells possessing the LNK1 allele with a miR1245 mimic resulted in 25 fold decrease in mRNA NKG2D level versus only 2 fold decrease in mRNA NKG2D expression in HNK1 allele derived NK cells, thus suggesting that the 3′UTR SNP may regulate the expression of NKG2D through its binding to the putative repressor miR1245. These findings provide evidence that the NKG2D 3′UTR polymorphism is functional, and that the NK cells from donors with the HNK1 genotype exert higher cytotoxicity through their increased expression of NKG2D, thereby resulting in an improved outcome for bone marrow transplantation.

Disclosures:
No relevant conflicts of interest to declare.
Impaired Ribosome Maturation In Human Cells Depleted of Shwachman-Diamond Syndrome Protein SBDS
Authors: Sezgin Gulay , Nihrane Abdallah , Henson Adrianna , Wattenberg Max , Ellis Steven , Liu Johnson M. 
Published: October 2019

Abstract
Abstract 2242

Background:
Shwachman-Diamond syndrome (SDS) is an autosomal recessive disorder characterized by pancreatic exocrine dysfunction, neurocognitive and skeletal abnormalities, and bone marrow failure. Mutations in SBDS have been shown to cause SDS. From experiments on its yeast ortholog (Haematologica 2010. 95:57-64), SBDS has been implicated in maturation and function of the 60S ribosomal subunit. In particular, subunit maturation in the SDS yeast model was associated with delayed export and accumulation of 60S-like particles in the nucleoplasm.

Methods and Results:
To clarify its role in human cells, erythroleukemia TF-1 cells were transduced with lentiviral vectors expressing short hairpin RNA (shRNA) against SBDS. Immunoblot assays confirmed approximately 60% knockdown in individual TF-1 cell clones expressing different shRNAs. The growth and hematopoietic colony forming potential of TF-1 knockdown cells were markedly hindered when compared to cells stably transduced with shRNA against a scrambled SBDS sequence. Using Hoechst 33342/Pyronin Y staining and flow cytometry, we also found an increased percentage of knockdown cells retained at the G0/G1 cell cycle phase. To address whether near-complete knockdown of SBDS affected ribosome synthesis as it does in yeast cells, we silenced SBDS in A549 cells. Our data revealed a reduction in polysomes but in contrast to what was observed in yeast, there was no evidence of half-mer polysomes indicative of decreased 60S subunits participating in translation. The absence of half-mers is not unusual in mammalian systems, so to better analyze the effect of SBDS on 60S subunit maturation subunit localization was assessed by co-transfection with a vector expressing a fusion between human RPL29 and enhanced GFP. Preliminary studies indicated a higher percentage of SBDS-depleted cells with nuclear localization of 60S subunits, when compared with normal controls (Fig. 1).

Conclusions:

Disclosures:
No relevant conflicts of interest to declare.
Distinct Impact of Imatinib on Growth In Prepubertal and Pubertal Children with Chronic Myeloid Leukemia
Authors: Shima Haruko , Tokuyama Mika , Tanizawa Akihiko , Tono Chikako , Hamamoto Kazuko , Muramatsu Hideki , Watanabe Akihiro , Hotta Noriko , Ito Masaki , Kurosawa Hidemitsu , Kato Koji , Tsurusawa Masahito , Horibe Keizo , Shimada Hiroyuki 
Published: October 2019

Abstract
Abstract 2277
Imatinib is now widely used for treating chronic-phase chronic myeloid leukemia (CML) in children as well as in adults, and long-term adverse effects of imatinib therapy in children are now gaining attention. One of its adverse effects is the negative impact on growth in children, suggested by 3 recently published case reports. However, the incidence or prospect of growth impairment resulting from imatinib treatment has not been fully elucidated.
In this study, we retrospectively analyzed the clinical records of 48 children with chronic-phase CML who were treated with imatinib as a first-line therapy between 2001 and 2006. The median age at diagnosis was 9 years (2 to 15 years). Cumulative change in height while on imatinib was assessed using the height standard deviations score (height-SDS), the converted height data from age- and sex-adjusted Japanese norms. Our data indicated that growth impairment (decrease in height-SDS) was observed in 72.9% of the patients, with median maximum reduction in height-SDS of 0.61 during imatinib treatment. Growth impairment was noticeable in children who were prepubertal at the commencement of imatinib treatment, while only mild or no growth impairment (with no decrease of height-SDS) was observed in most patients who were pubertal at the commencement of imatinib treatment. Furthermore, in prepubertal children with growth impairment, growth velocity tended to recuperate concomitant with pubertal maturation, suggesting that imatinib has little impact on growth during puberty. To our knowledge, this is the first report to describe and compare the distinct inhibitory effect of imatinib on growth in prepubertal and pubertal children with CML.
Although the introduction of imatinib was a breakthrough in CML therapy, the possibility of continuous remission after discontinuation of imatinib remains uncertain. Thus, the possibility of adverse effects of long-term exposure to imatinib has become a huge issue, especially when treating children. We consider that it is important to promote awareness of growth deceleration in children, especially in young children who started imatinib treatment before puberty and are inevitably going to be subject to prolonged exposure.

Disclosures:
No relevant conflicts of interest to declare.
Methylation and Silencing of miRNA-124 In Hematopoietic Cells by EVI1
Authors: Senyuk Vitalyi , Premanand Kavitha , Xu Peng , Cattaneo Francesca , Dickstein Jerome , Nucifora Giuseppina 
Published: October 2019

Abstract
Abstract 2476
The inappropriate expression of EVI1 is associated with aggressive myelodysplastic syndromes (MDS) and acute myeloid leukemia. We previously showed that in vivo EVI1 causes an MDS-like disease in mice and that in vitro it alters cell cycling, self-renewal, and differentiation pathways of primary bone marrow (BM) cells. It is likely that these alterations contribute to the oncogenic potential of EVI1. MicroRNAs (miRNA) are small noncoding RNAs that are 21 to 25 nt in length that up- and down-regulate gene expression during cell development, proliferation, differentiation, and apoptosis. MiRNAs play a critical role in solid and hematopoietic cancers. We found that in hematopoietic cells the expression of several miRNAs is significantly altered by EVI1. Among them, miRNA-124 is strongly downregulated in EVI1-expressing primary BM and 32Dcl3 cells. To evaluate the role of miRNA-124 in primary murine BM cells, we isolated Lin- cells and infected the cells with the empty vector, EVI1, or both EVI1 and miRNA-124. We confirmed that EVI1 alters cellular pathways regulating self-renewal, S1 phase entry, and differentiation. More importantly, however, we found that when miRNA-124 is co-expressed with EVI1, the expression of proteins such as Cyclin D3 and BMI-1, that control some of these pathways, is normalized. These results suggest that the effects of EVI1 are mediated by miRNA-124 repression. We hypothesized that the down-regulation of miRNA-124 could be associated with inappropriate DNA methylation of the miRNA. Both in man and mouse, there are three known alleles of miRNA-124. In the mouse, the alleles are located on chromosome bands 2H4, 3A1, and 14D1. Analysis of the three alleles indicates that miRNA-124-3 harbors the larger number of CpG dinucleotides, including 24 CpG within a stretch of 190 bp upstream of and overlapping the stem-loop start-site. By using the bisulfite DNA sequencing method, we found that in BM cells the number of methylated CpG dinucleotides in this region is significantly increased after EVI1 expression. The DNA methylation is mostly centered in two clusters, which we named cluster I and cluster II. These data clearly show that miRNA-124 is a critical target of EVI1 in human diseases.

Disclosures:
No relevant conflicts of interest to declare.
Adoptive Transfer of Primed CD62L+ T Cells Mediate Selective GVL In a Murine Model of Pediatric ALL
Authors: Qin Haying , Meadors Joanna L. , Fry Terry J. 
Published: October 2019

Abstract
Abstract 2535

Background:
While current upfront therapy will cure over 80% of patients with pediatric ALL, treating recurrence remains a major challenge. Blood or marrow transplantation (BMT) offers a curative option but approximately 50% of patients undergoing BMT will relapse. Donor lymphocyte infusions (DLIs) have demonstrated efficacy in myeloid leukemia but are much less effective for ALL. Strategies to improve the potency of DLI can result in GVHD and may compromise outcome. Thus, we explored strategies to improve on the potency and specificity of the graft versus leukemia response in a murine model of pediatric ALL.

Methods:
A transplantable cell line was generated from E2a-PBX1 transgenic mice (that express a recurring translocation t(1;19) present in approximately 5% of all pediatric ALL). Lethally irradiated C57Bl/6 (H2b) mice received T-cell-depleted C3H.SW (H2b, minor histocompatibility antigen miHA mismatch allogeneic) or C57Bl/6 (syngeneic) bone marrow followed by E2aPBX1 IV on day +6. A purified T cell DLI was given on day +7. DLI donors were primed with irradiated cells as indicated intraperitoneally 14 days prior to harvest. In some experiments T cell subsets were purified using magnetic beads.

Results:
E2a-PBX1 is a pre-B cell ALL that expresses B220, BP-1, CD43 and the alpha chain of the IL-7 receptor. The distribution of leukemia is similar to that observed in humans with bone marrow, lymph node, liver, spleen and central nervous system involvement confirmed by necropsy and imaging following injection of luciferase-expressing cells. Administration of naive T cells (6×106) following syngeneic or allogeneic BMT was not effective at treating E2a-PBX1 indicating that the presence of miHA did not increase the efficacy of naïve T cells consistent with the poor response rate to DLI in patients with ALL. However, primed T cell DLI (6×10ee6) from a donor immunized by irradiated E2a-PBX1 resulted in a statistically significant prolongation of survival in syngeneic (and cure in allogeneic BMT models suggesting the presence of tumor-specific antigens as well as a contribution from miHA. However, mice receiving sufficient primed allogeneic T cells for cure developed GVHD-associated weight loss and 40% late mortality (after 30 days). While purified, primed CD4 or CD8 T cells prevented GVHD associated mortality, 40–60% of mice developed leukemia. Remarkably, mice receiving magnetic-bead purified CD62L+ T cells from primed allogeneic donors were cured of leukemia with no GVHD-associated weight loss or mortality.

Conclusion:
Naïve T cells (analogous to DLI given post-relapse in the clinic) were ineffective at treating ALL our model. However, priming of allogeneic DLI donors with whole tumor cells results in cure but with the development of GVHD. CD62L+ expressing T cells from primed donors mediate curative GVL without GVHD.

Disclosures:
No relevant conflicts of interest to declare.
Weight Loss: An Important but Often Overlooked Clue for the Diagnosis of Cancer
Authors: Peddi Prashanth , Chitneni Shalini , Noel Mary , Schwartz Kenneth A. 
Published: October 2019

Abstract
Abstract 2552

Background:
One of the primary goals of care for cancer patients is to detect growth and or recurrence as early as possible. We retrospectively evaluated unexplained weight loss of 5% or more as an indicator of cancer growth or recurrence in patients who were followed in a hematology/oncology clinic. In addition, we noted the frequency of physician recognition of the weight loss as well as the time delay from the onset of weight loss to detection of new cancer/metastasis.

Methods:
A search of the data base in the electronic medical record identified 90 cancer patients whose weight had decreased by 5 % or more over a maximal time period of 3 years. Weight loss in 30 of the patients could be explained as intentional (diet, exercise, gastric bypass) or because of advanced cancer or diuresis or documentation error. These 30 patients were excluded from the analysis.

Results:
The 60 included patients were evaluated on serial clinic visits, average 5.5 visits per patient. Weight loss of 5% or more that was not addressed on the first two visits was categorized as a missed clue. This occurred in 52 of the 60 (86%) patients. Among the 52 patients 11 (21%) had new cancers with weight loss documented in the medical record, but overlooked by their physician. Of the remaining 8 patients whose weight loss was addressed 3 (37%) had new cancers. The reasons for the weight loss in the remaining patients without new cancers were due to side effects of chemotherapy, dysphagia, recent hospitalization, infection and unknown. In patients whose weight loss was not noted after 2 clinic visits the time lag between the onset of weight loss and diagnosis of advancing cancer varied from 0.5 months to 29 months with a mean delay of 8.9 months. This compares with a mean delay of 0.9 months in those 8 patients whose evaluation was initiated as soon as their weight loss was documented in the chart (p=0.03).

Conclusion:
1. Weight loss in 23% of hematology/oncology patients was associated with cancer growth or recurrence. 2. The importance of weight loss as a clue to the diagnosis of a new cancer or to cancer progression is frequently not appreciated resulting in a significant delay in initiating diagnostic investigations.

Disclosures:
No relevant conflicts of interest to declare.
A Potential Epigenetic Bookmarking Function for the Hematopoietic Transcription Factor GATA-1.
Authors: Kadauke Stephan , Lamonica Janine M , Lau Alan , Chou Margaret , Blobel Gerd 
Published: October 2019

Abstract
Abstract 2601
Hematopoietic lineage choice decisions are stably maintained through many cell divisions. For example, erythroid precursor cells undergo several rounds of cell division during their maturation. During each mitosis, most transcription factors separate from chromatin causing transcription to cease globally. Mitosis therefore poses a challenge for transcription factors to re-associate with the appropriate target sites in chromatin of newborn cells. The epigenetic mechanisms that cement lineage stability and resist cell reprogramming during mitosis are poorly understood, although recent evidence supports the idea that “bookmarking” factors that remain associated with mitotic chromatin may play a role in this process. We therefore investigated whether the hematopoietic transcription factor GATA-1 might be retained at specific sites during mitosis. GATA-1 controls the expression of essentially all erythroid-specific genes and might therefore play a role in maintaining erythroid gene expression programs throughout the cell cycle. Surprisingly, we found that while a substantial fraction of GATA-1 dissociates from chromatin in mitosis, foci of high GATA-1 density are present within mitotic chromatin. To determine the exact locations of GATA-1 binding during mitosis, we developed a method to highly purify mitotic erythroid cells in sufficient quantities for chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-Seq). These experiments revealed that a subset of sites bound by GATA-1 during interphase is occupied continuously throughout mitosis. Importantly, continuously GATA-1-occupied sites are enriched at promoters and cis-regulatory elements of genes coding for key developmental regulators of hematopoiesis (e.g., Fog1/Zfpm1, Gata2, Lyl1) but are notably absent at erythroid physiological and structural genes (e.g., Hba, Hbb, Epb4.9). To examine the importance of mitotic chromatin binding by GATA-1, we engineered a version of GATA-1 bearing a mitosis-specific degron that targets GATA-1 for degradation during mitosis but not interphase. Preliminary results show that mitotically degraded GATA-1 fails to induce differentiation when expressed in GATA-1-null erythroblasts. This suggests an important mitotic function for GATA-1. Current work focuses on delineating the mechanism by which continuous chromatin occupancy of GATA-1 throughout mitosis ensures proper erythroid differentiation. The results will be presented and discussed at the meeting.

Disclosures:
No relevant conflicts of interest to declare.
Estimated GFR Derived From Plasma Creatinine by Mass Spectrometry (MSMS) Is A Reliable Measure of Renal Function During the Hyperfiltration Phase In Sickle Cell Disease (SCD)
Authors: Inusa Baba , Booth Caroline , Turner Charles , Appleby Helen , Padmore-Penniston Giselle , Dalton R. Neil 
Published: October 2019

Abstract
Abstract 2649

Aim:
The hypothesis is that a height based eGFR formula using creatinine measured by mass spectrometry is a reliable measure of GFR in children with SCD.

Background:
The kidney is a particularly sensitive to hypoxia and renal failure is a major cause of morbidity and mortality in SCD. Children with SCD commonly hyper filtrate, thus making it difficult to establish a reliable Glomerular Filtration Rate (GFR) measure. It is essential to correctly assess the GFR, in order to identify when it begins to fall back towards normal and then starts to decline. Reporting of estimated glomerular filtration rate (eGFR) derived from plasma creatinine (pCr) measurements is now recommended for the classification and monitoring of patients with chronic kidney disease. The new MDRD formula requires the use of pCr methods traceable to stable isotope dilution mass spectrometry (MS). In children the recommendation is to use one of the formulae based on height (Ht), e.g. Schwartz et al1, Morris et al2, both of which were derived using traditional Jaffe creatinine methodology; eGFR = 40 × Ht (cm)/pCr (μmol/l). The introduction of MS traceable creatinine methods requires a review of the k factor. This correlation has never been validated in hyper filtration/or children with SCD.

Methods:
43 HbSS patients, age range 5–20yrs, attending the Evelina Children's Hospital were studied, including transfused and non-transfused patients. The plasma samples were also used for the measurement of plasma creatinine by stable isotope dilution mass spectrometry. eGFR was calculated using k=31.

Results:
Inutest GFR ranged from 70–175 ml/min/1.73m2. There was significant correlation between eGFR and inutest GFR (P<0.01, r=0.68).

Conclusions:
These preliminary data suggest that eGFR should prove valuable in monitoring GFR in children with SCD, even during hyper filtration, providing the constant is appropriately adjusted for the analytical method of creatinine.

Disclosures:
Inusa: Novartis: Research Funding.