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Reflecting the increasing risk in elderly patients with diffuse large B cell lymphoma (DLBCL), prognostic predictors other than the International Prognostic Index have attracted more attention. This study presents the first analysis of the prognostic utility of the Geriatric Nutritional Risk Index (GNRI) in combination with the Charlson Comorbidity Index (CCI) for overall survival (OS) in elderly DLBCL patients. A multicentre retrospective was conducted on a cohort of 451 patients (≥65 years). The GNRI and CCI were independent predictors in a multivariate Cox proportional hazard model. There was a nonlinear correlation between the GNRI and OS in a Cox model with restricted cubic spline. Multivariate receiver operating characteristic curves showed a significant improvement in prediction accuracy when the GNRI was added to CCI. Adding the GNRI to CCI yielded a significant category-free net reclassification improvement (0Á556; 95% CI: 0Á378-0Á736, P < 0Á001) and integrated discrimination improvement (0Á094; 95% CI: 0Á067-0Á122, P < 0Á001). The decision curve analysis demonstrated the clinical net benefit associated with the adoption of the GNRI. The GNRI was not only a predictor of OS but also remarkably improved the prognosis prediction accuracy when incorporated with the CCI, having the ability to stratify the prognosis of elderly DLBCL patients.

The major mechanism of imatinib (IM) resistance of CML is the reactivation of ABL kinase either through BCR‐ABL gene amplification or mutation. We investigated the cytotoxicity of a pan‐ABL tyrosine kinase inhibitor, ponatinib, and a pan‐histone deacetylase inhibitor, panobinostat, against IM‐resistant CML cells in vitro. Two different IM‐resistant cell lines, K562/IM‐R1 and Ba/F3/T315I were evaluated in comparison with their respective, parental cell lines, K562 and Ba/F3. K562/IM‐R1 overexpressed BCR‐ABL due to gene amplification. Ba/F3/T315I was transfected with a BCR‐ABL gene encoding T315I‐mutated BCR‐ABL. Ponatinib inhibited the growth of both K562/IM‐R1 and Ba/F3/T315I as potently as it inhibited their parental cells with an IC 50 of 2–30 nM. Panobinostat also similarly inhibited the growth of all of the cell lines with an IC 50 of 40–51 nM. This was accompanied by reduced histone deacetylase activity, induced histone H3 acetylation, and an increased protein level of heat shock protein 70, which suggested disruption of heat shock protein 90 chaperone function for BCR‐ABL and its degradation. Importantly, the combination of ponatinib with panobinostat showed synergistic growth inhibition and induced a higher level of apoptosis than the sum of the apoptosis induced by each agent alone in all of the cell lines. Ponatinib inhibited phosphorylation not only of BCR‐ABL but also of downstream signal transducer and activator of transcription 5, protein kinase B, and ERK1/2 in both K562/IM‐R1 and Ba/F3/T315I, and the addition of panobinostat to ponatinib further inhibited these phosphorylations. In conclusion, panobinostat enhanced the cytotoxicity of ponatinib towards IM‐resistant CML cells including those with T315I‐mutated BCR‐ABL.

Background: U2AF1 forms a heterodimer for the recognition of the 3' splice site during pre-mRNA splicing. Somatic U2AF1 mutations are present in approximately 10% of MDS patients. Most U2AF1 mutations are recurrent at 2 highly conserved hotspots, while non-canonical mutations are rare. U2AF1S34 and U2AF1Q157 mutations map within the zinc finger domains of the protein, resulting in distinct downstream effects. We have previously shown that U2AF1Q157 mutant patients have distinct splicing patterns compared to U2AF1WT with a set of misspliced targeted genes, including ARID2 and EZH2. In contrast, recent work focusing on S34 suggests a distinct subset of misspliced genes, including ATG7 (Park SM, Molecular Cell, 2016). The biological and clinical implications of these 2 distinct mutations are unknown. We investigated the differences between these mutations with respect to clinical outcomes and molecular background, including their impact on clonal architecture. Methods: We first collected molecular and clinical data on a cohort of 1700 patients with myeloid neoplasms (median follow up 1.0 year, range 1-5 years), median age was 65 years (range, 11-93). Targeted deep sequencing of a panel of frequently mutated genes (64) was applied. Our analyses included somatic mutational patterns, clonal hierarchy, and mutational correlation of the cohort of patients with U2AF1S34 and U2AF1Q157 and those without mutations in this gene. U2AF1 mutations were found in 5% (78/1700) of patients, all of them were missense and in a heterozygous configuration. Results: Both mutations were equally distributed in the cohort: U2AF1S34 (45%, 35/78), and U2AF1Q157 (46%, 36/78). Other mutations (Q84, E124, E152, and R156) were detected at a lower frequency (9%). We then dissected the clonal hierarchy of both U2AF1 mutations and found that 44% (34/77) were ancestral while 56% (43/77) were secondary. In MDS, most U2AF1 mutations (77%, P=.002) were dominant, while subclonal U2AF1 mutations were evenly distributed between the subentities. U2AF1S34 or U2AF1Q157 were equally likely to be dominant (21% vs. 27%; ancestral events; P=.09, respectively). Similarly, S34 and Q157 mutant clones had similar median variant allele frequencies (3-52% vs. 8-64%). U2AF1 S34 mutant cases had similar OS to patients carrying U2AF1Q157 (N=35 vs. N=36; 10 vs. 15 months; P=.209; LogR=.65). When we compared the impact of ancestral vs. secondary U2AF1S34 and U2AF1Q157 we found that MDS patients carrying ancestral U2AF1 mutations had a shorter OS compared to MDS patients carrying secondary U2AF1 patients (N=26 vs. N=18; 13 vs. 34 months; LogR=.04). Of note, ancestral U2AF1S34 patients had shorter OS compared to ancestral U2AF1Q157 patients (13 vs.11; 10 vs.15 months; P=.03; LogR=.86). Given these differences, we also investigated the mutational spectrum of U2AF1MUT patients. Cross sectional analysis identified that the top genes mutated in the U2AF1 mutant cohort were: ASXL1 (26%), BCOR/L1 (15%), TET2 (13%), DNMT3A and PHF6 (12%), ETV6 (10%), RUNX1 and STAG2 (9%), and SETBP1 (8%). Transcriptional factor and DNA-methylation genes were predominantly mutated in U2AF1MUT patients (35% and 24%, respectively). Exploring the association between S34/Q157 vs. other gene mutations, S34 co-occurred with BCOR/L1 mutations (P=.007, 24%), while Q157 mutations co-occurred with ASXL1 (P=.003, 44%) irrespective of their rank in the clonal hierarchy. When S34 was the dominant mutation, secondary mutations included ETV6, BCOR, and CUX1. In contrast, when Q157 was the ancestral event, secondary mutations included ASXL1 and DNMT3A. Subclonal S34 occurred in the context of ancestral RUNX1, BCOR/L1, CUX1 and DNMT3A, while subclonal Q157 followed ancestral ASXL1, EZH2, PHF6 and TET2. Conclusion: In sum, U2AF1S34 and U2AF1Q157, consistent with their differential missplicing consequences, create a distinct molecular milieu leading to differences in clinical outcomes. Disclosures Makishima: The Yasuda Medical Foundation: Research Funding. Carraway:Novartis: Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Research Funding, Speakers Bureau; Baxalta: Speakers Bureau; Amgen: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees. Maciejewski:Celgene: Consultancy, Honoraria, Speakers Bureau; Alexion Pharmaceuticals Inc: Consultancy, Honoraria, Speakers Bureau; Apellis Pharmaceuticals Inc: Membership on an entity's Board of Directors or advisory committees.

Cytarabine (ara‐C) is the key agent for treating acute myeloid leukemia. After being transported into leukemic cells, ara‐C is phosphorylated, by several enzymes including deoxycytidine kinase (dCK), to ara‐C triphosphate (ara‐CTP), an active metabolite, and then incorporated into DNA, thereby inhibiting DNA synthesis. Therefore, the cytotoxicity of ara‐C depends on the production of ara‐CTP and the induction of apoptosis. Here, we established a new ara‐C‐resistant acute myeloid leukemia cell line (HL‐60/ara‐C60) with dual resistance characteristics of the anti‐antimetabolic character of decreased ara‐CTP production and an increase in the antiapoptotic factors Bcl‐2 and Bcl‐XL. We further attempted to overcome resistance by augmenting ara‐CTP production and stimulating apoptosis. A relatively new nucleoside analog, 9‐β‐d‐arabinofuranosylguanine (ara‐G), and the small molecule Bcl‐2 antagonist YC137 were used for this purpose. HL‐60/ara‐C60 was 60‐fold more ara‐C‐resistant than the parental HL‐60 cells. HL‐60/ara‐C60 cells exhibited low dCK protein expression, which resulted in decreased ara‐CTP production. HL‐60/ara‐C60 cells were also refractory to ara‐C‐induced apoptosis due to overexpression of Bcl‐2 and Bcl‐XL. Combination treatment of ara‐C with ara‐G augmented the dCK protein level, thereby increasing ara‐CTP production and subsequent cytotoxicity. Moreover, the combination of ara‐C with YC137 produced a greater amount of apoptosis than ara‐C alone. Importantly, the three‐drug combination of ara‐C, ara‐G and YC137 provided greater cytotoxicity than ara‐C+ara‐G or ara‐C+YC137. These findings suggest possible combination strategies for overcoming ara‐C resistance by augmenting ara‐CTP production and reversing refractoriness against the induction of apoptosis in ara‐C resistant leukemic cells.