ALBERT

Description: Background The nuclear export protein chromosomal region maintenance 1 (CRM1) may play a role in human neoplasia and serve as a novel target for cancer treatment. Investigators recently developed orally bioavailable selective inhibitors of nuclear export (SINEs) that irreversibly bind to CRM1 and block its function. Our objective was to evaluate the therapeutic efficacy of the novel SINEs KPT-185 and KPT-276 against NHL in vitro and in vivo and elucidate the mechanism of CRM1 inhibitor-mediated antitumor activity. Methods Cell viability, apoptosis and cell cycle were evaluated in 8 B and T cell lymphoma cell lines (Jeko-1, Mino, Granta519, Sp53, RL, Hut102, Hut78 and Jurkat) which were treated with KPT-185; Primary tumor cells from 5 patients and normal human lymphocytes from 2 healthy volunteers were treated directly with KPT-185. Tumor suppressor proteins were detected by western blot to explore the possible mechanisms of KPT-185 inducing lymphoma cells growth inhibition and apoptosis. BALB/c nude mice bearing Jeko-1 tumors were treated orally with KPT-276 (similar structure to KPT-185, but improved animal pharmacokinetics) to examine the efficacy and side-effects of KPT-276. Results KPT-185 displayed potent antiproliferative properties at submicromolar concentrations (half-maximal inhibitory concentrations, 60-120 nM) and induced cell-cycle arrest and apoptosis in NHL cell lines and normal lymphocytes. The antitumor activity mainly consisted of regulating cell growth and apoptosis mechanisms by inducing caspase cleavage and downregulating the expression of antiapoptotic proteins such as CRM1, nuclear factor-kB, and survivin. Furthermore, oral administration of KPT-276 significantly suppressed tumor growth and prolonged survival in mice with NHL xenografts without any major toxic effects (P 〈 0.001). Analysis of tumor remnants in the mice demonstrated that KPT-276 trapped the antiapoptoic protein survivin within the nuclei of NHL cells. Conclusions We observed the biologic and pharmacologic activity of CRM1-inhibiting SINEs in NHL cells, primary NHL tumor samples, and a murine NHL xenograft model. SINE CRM1 inhibitors inhibited growth of lymphoma cells both in vitro and in vivo. The antitumor activity of the SINEs resulted primarily from induction of caspase activity and downregulation of expression of antiapoptoic proteins such as survivin and NF-kB. The preclinical in vitro and in vivo results reported herein support further study of CRM1-inhibiting SINEs as novel therapeutics for NHL. Disclosures: No relevant conflicts of interest to declare.

Description: Key Points MINK1 promotes hemostasis and thrombosis in vivo. MINK1 specifically regulates platelet dense-granule secretion.

Description: Abstract 1433 BACKGROUND High levels of 2-HG in serum were found among AML cases with IDH1/IDH2 mutations. However, the impact of 2-HG levels on biological characteristics and clinical outcomes has not been systematically evaluated in a large cohort of AML patients. METHODS Serum 2-HG levels in 699 patients with hematologic malignancies, including 405 AML patients, were measured by GC-TOFMS. Clinical prognostic power of 2-HG and genetic risk factors associated with 2-HG were also evaluated in AML patients. RESULTS Among all patients with hematopoietic malignancies investigated, high serum 2-HG levels were observed only in AML group. 64 out of 405 (15.8%) AML patients displayed aberrantly higher levels (7.14±2.11μg/ml) of 2-HG. Compared to cases with normal 2-HG (3.65±1.02μg/ml), these patients showed a higher prevalence in AML-M0/M1 subtypes, a closer correlation with mutated IDH1/2 genes, a distinct gene expression profile and an aberrant DNA methylation status in bone marrow blasts. Additionally, the patients with high 2-HG were associated with higher serum levels of α-ketoglutarate (α-KG) and glutamate, suggesting presence of impaired metabolic pathway involved in the biosynthesis of 2-HG. Univariate and multivariate analyses indicate that high level of 2-HG is among the most significant negative indicators for complete remission (CR) rate, overall survival (OS) and event-free survival (EFS) either in all AML cases or in cases with cytogenetically normal AML (CN-AML). CONCLUSIONS Serum 2-HG is an independent prognostic marker in AML. Patients with high 2-HG had significantly higher frequency of IDH1/IDH2 gene mutations and unfavorable prognosis compared to those with normal 2-HG. Disclosures: No relevant conflicts of interest to declare.

Description: Objective: To summary the clinical features of Chinese patients with paroxysmal nocturnal hemoglobinuria (PNH) diagnosed by FLAER. Methods: The clinical data of 98 cases diagnosed by FLAER from September 2011 to March 2014 were analyzed retrospectively, including clinical features, laboratory examination results and complications. Patients were divided into three clinical groups according to the standard proposed by the International PNH Interest Group. This classification has been applied to each patient considering the clinical characteristics of the disease, bone marrow failure and PNH clone size. Statistical analysis: We presented continuous data as mean and standard deviation or median and interquartile range (IQR), with extreme values. The distributions of the presentation characteristics were compared among the three subcategories and between classic PNH and PNH-sc/AA by chi-square test or Fisher exact test when necessary for qualitative characteristics, and by Kruskal-Wallis (three subcategories) or Mann-Whitney (two groups) test for continuous characteristics. Spearman's rank correlation coefficient was used to measure correlations. Overall survival (OS) estimated by the Kaplan-Meier method was compared using the log-rank test. The Cox proportional hazards model was used to assess the risk factors for survival in both univariate and multivariate analyses. All of the analyses were performedusing statistical package SPSS 17.0. P

Description: Key Points Acute myeloid leukemia (AML) patients present an altered glucose metabolism signature. A panel of 6 metabolite biomarkers involved in glucose metabolism are identified with prognostic value for cytogenetically normal AML.

Description: Objective: The aim of this study was to assess the risk of HBV reactivation in HBsAg-positive or negative, HBcAb-positive patients with aplastic anemia (AA) receiving immunosuppressive therapy. Methods: We analyzed clinical data of 60 AA patients with HBV infection out of 201 cases. Entecavir or lamivudine therapy was initiated if HBV reactivation was encountered, or used as antiviral prophylaxis regimen for HBsAg-positive patients. Result: Among 60 AA patients, 12 were chronically infected and 48 were previously exposed. There was no difference in clinical features in AA patients with or without HBV infection. The prevalence of non-severe AA (NSAA) progressed to severe AA (SAA) was similar in two groups (35.6% vs 42.7%, p=1.0). In NSAA group, the response rate to CsA, to ATG and CsA, and progression to SAA were similar in patients with or without HBV infection (35.7% vs 35.3%, p〉0.05; 42.8% vs 58.8%, p= 1.0; 35.5% vs 42.7%, p= 0.414). In SAA group, patients with or without HBV infection responded to ATG and CsA therapy similarly (83.33% vs 59.0%, p = 0.252). HBV reactivation was occurred in all 5 HBsAg positive patients without any antiviral therapy, while no HBV reactivation happened in other 7 patients received antiviral therapy. Disease course (RR=1.012, p=0.036) and absolute reticulocyte count (RR=11.556, P=0.025) were the risk factors for HBV reactivation by univariate analysis. Logistic regression indicated that HBsAg positivity without preventive therapy was the only strong factor for HBV reactivation. Conclusion: Antiviral prophylaxis is recommended for HBsAg-positive patients with AA who will receive IST because of high rate of HBV reactivation. HBV infection has no influence on the clinic course of AA, and antiviral therapy does not affect the efficacy of IST. Disclosures No relevant conflicts of interest to declare.

Description: Fetal hemoglobin (HbF) modulates the phenotype of sickle cell anemia. In the Middle East and India the HbS gene is often on an Arab-Indian HBB haplotype that is associated with high HbF levels. HbF is “normally” distributed in this population with a mean ~20%. In African HbS haplotypes, HbF levels are much lower (mean value ~6%) with a highly skewed distribution. BCL11A is an important modulator of γ-globin gene (HBG2 and HBG1) expression and BCL11A is regulated by erythroid specific enhancers in its 2nd intron. The enhancers consist of 3 DNase hypersensitive sites (HS) +62, +58 and +55 kb from the transcription initiation site of this gene. Polymorphisms (SNPs) in these enhancers are associated with HbF. The strongest association with HbF levels in African Americans with sickle cell anemia was with rs1427407 in HS +62 and to a lesser extent, rs7606173 in HS+55. Using the results of whole genome sequencing of 14 AI haplotype patients—half with HbF 20%—6 SNPs in the BCL11A enhancer region, rs1427407, rs7599488, rs6706648, rs6738440, rs7565301, rs7606173 and 2 indels rs3028027 and rs142027584 (CCT, CCTCT and AAAAC respectively), were detected as possibly associated with HbF level. There were no novel polymorphisms detected. We genotyped the 6 SNPs and studied their associated haplotypes in 137 Saudi (HbF18.0±7.0%) and 44 Indian patients (HbF23.0±4.8%) with the Arab-Indian HBB haplotype; 50 African Americans with diverse African haplotypes, including 4 Senegal haplotype heterozygotes, (20 with HbF 17.2±4.6% and 30 with HbF 5.0±2.5%) and imputed genotypes for these SNPs in 847 African Americans with sickle cell anemia and diverse haplotypes (HbF 6.6±5.5%). Four SNPs (rs1427407, rs6706648, rs6738440, and rs7606173) in the HS sites showed consistent associations with HbF levels in all 4 cohorts. Haplotype analysis of these 4 SNPs showed that there were 4 common and 10 rare haplotypes. The most common, GCAG, was found in ~54% of Arab-Indian haplotype carriers (HbF, ~20%) and in ~33% of African origin haplotype carriers (HbF, ~5.5%). Two haplotypes, GTAC and GTGC, were carried by ~40% of African American patients and were associated with lower levels of HbF (3.6%-4%). These same haplotypes were carried by 18% of Arab-Indian haplotype carriers and their average HbF level was 17%. These differences were significant. Haplotype TCAG was present in 20% of Arab-Indian and 25% of African haplotype cases, and carriers had on average higher HbF levels (~22% in the Arab-Indian haplotype, ~8% in African Americans). The analysis shows that: BCL11A enhancer haplotypes are differentially distributed among patients with the HbS gene on Arab-Indian or African origin haplotypes; haplotype pairs TCAG/TCAG and GTAC/GTGC are associated with the highest and lowest HbF levels in all the studied groups; the population-specific prevalence of HbF BCL11A enhancer haplotypes are likely to explain the different distributions of HbF in African origin and Arab-Indian haplotypes but do not account for the differences in average population levels of HbF or the high HbF of the Arab-Indian haplotype. Novel SNPs in BCL11A do not explain the high HbF of the Arab-Indian haplotype. Other important loci must have a predominant role in the differential expression of HbF among HbS Arab-Indian haplotype carriers. Disclosures No relevant conflicts of interest to declare.

Description: Introduction Splenic rupture is a rare but serious adverse event associated with the use of Granulocyte-Colony Stimulating Factor (G-CSF) and Granulocyte Macrophage-Colony Stimulating Factor (GM-CSF). Instances of spontaneous splenic rupture following administration of these hematopoietic growth factors have been sporadically documented in case reports. We aimed to conduct a more comprehensive study to generate signal for splenic rupture with G-CSF/GM-CSF therapy using disproportionality analysis. Methods The United States Food and Drug Administration (FDA) Adverse Events Reporting System (FAERS) database, a pharmacovigilance database, was used to extract data. All reported splenic rupture cases between January 1, 1991 and December 31,2019 for G-CSF or GM-CSF were collected by using the search terms "Pegfilgrastim", "Filgrastim", "Lenograstim", "Filgrastim-sndz", "Sargramostim" and "Pegfilgrastim-jmdb". We used reporting odds ratio (ROR) for proportionality analysis. ROR was calculated by SPSS 26 and considered significant with p value