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28.  A phase 2 study of MK-0457 in patients with BCR-ABL T315I mutant chronic myelogenous leukemia and philadelphia chromosome-positive acute lymphoblastic leukemia 
Blood Cancer Journal  2014;4(8):e238-.
Aurora kinase overexpression has been observed in patients with hematologic malignancies. MK-0457, a pan-aurora kinase inhibitor that also inhibits the ABL T315I mutant, was evaluated to treat patients with chronic myelogenous leukemia (CML) or Philadelphia chromosome (Ph+) acute lymphoblastic leukemia (ALL) with the T315I mutation. Adults with Ph+ chronic phase (CP)-, accelerated phase (AP)- or blast phase (BP)-CML, or ALL and documented BCR-ABL T315I mutation were treated with a 5-day continuous infusion of MK-0457 administered every 14 days at 40 mg/m2/h, 32 mg/m2/h or 24 mg/m2/h. Fifty-two patients (CP, n=15; AP, n=14; BP, n=11; Ph+ ALL, n=12) were treated. Overall, 8% of patients achieved major cytogenetic response; 6% achieved unconfirmed complete or partial response; 39% had no response. Two patients (CP CML) achieved complete hematologic response. No patients with advanced CML or Ph+ ALL achieved major hematologic response. The most common adverse event (AE) was neutropenia (50%). The most common grade 3/4 AEs were neutropenia (46%) and febrile neutropenia (35%). MK-0457 demonstrated minimal efficacy and only at higher, intolerable doses; lower doses were tolerated and no unexpected toxicities were observed. These data will assist in the development of future aurora kinase inhibitors and in the selection of appropriate target patient populations.
PMCID: PMC4219463  PMID: 25127392
29.  Percentage of urinary albumin excretion and serum-free light-chain reduction are important determinants of renal response in myeloma patients with moderate to severe renal impairment 
Blood Cancer Journal  2014;4(8):e235-.
Reversal of renal dysfunction significantly affects the prognosis of multiple myeloma (MM) with renal impairment (RI). There is no reliable test for predicting reversibility of RI in MM patients. We postulated that MM with high albuminuria may reflect glomerular disease that is difficult to reverse. Here, we examined the impact of urinary albumin excretion. We retrospectively analyzed 279 patients admitted to our hospital from April 2000 to December 2013. Clinical variables and laboratory data that may affect myeloma treatment response were extracted. The results were examined for relationship to renal response by univariate and multivariate analysis. RI (estimated glomerular filtration rate ≦50 ml/min per 1.73 m2) was observed in 116 patients (46%) and renal responses of renal complete response, renal partial response, renal minor response and no response were obtained in 46 (40%), 15 (13%), 13 (11%) and 42 (36%) patients, respectively. Although renal recovery was significantly associated with Durie–Salmon 1 or 2 (P=0.02), myeloma response better than very good partial response (P=0.03), involved free light-chain (iFLC) reduction from baseline 80% at day 12 (P=0.005), ≧95% at day 21 (P<0.001) and urinary albumin ≦25% on admission (P<0.001) on univariate analysis, only reduction of iFLC 95% at day 21 (P=0.015) and urinary albumin ≦25% (P=0.007) remained significant for any renal response. Our observation indicates that increased urinary albumin excretion >25% and reduction of iFLC ≦95% on day 21 were associated with favorable renal recovery in MM patients with RI, and were considered as negative predictors for renal response.
PMCID: PMC4219465  PMID: 25083819
30.  A pre-clinical model of resistance to induction therapy in pediatric acute lymphoblastic leukemia 
Blood Cancer Journal  2014;4(8):e232-.
Relapse and acquired drug resistance in T-cell acute lymphoblastic leukemia (T-ALL) remains a significant clinical problem. This study was designed to establish a preclinical model of resistance to induction therapy in childhood T-ALL to examine the emergence of drug resistance and identify novel therapies. Patient-derived T-ALL xenografts in immune-deficient (non-obese diabetic/severe combined immunodeficient) mice were exposed to a four-drug combination of vincristine, dexamethasone (DEX), L-asparaginase and daunorubicin (VXLD). ‘Relapse' xenografts were characterized by responses to drugs, changes in gene expression profiles and Connectivity Map (CMap) prediction of strategies to reverse drug resistance. Two of four xenografts developed ex vivo and in vivo drug resistance. Both resistant lines showed altered lipid and cholesterol metabolism, yet they had a distinct drug resistance pattern. CMap analyses reinforced these features, identifying the cholesterol pathway inhibitor simvastatin (SVT) as a potential therapy to overcome resistance. Combined ex vivo with DEX, SVT was significantly synergistic, yet when administered in vivo with VXLD it did not delay leukemia progression. Synergy of SVT with established chemotherapy may depend on higher drug doses than are tolerable in this model. Taken together, we have developed a clinically relevant in vivo model of T-ALL suitable to examine the emergence of drug resistance and to identify novel therapies.
PMCID: PMC4219466  PMID: 25083816
32.  Depletion of STAT5 blocks TEL–SYK-induced APMF-type leukemia with myelofibrosis and myelodysplasia in mice 
Blood Cancer Journal  2014;4(8):e240-.
The spleen tyrosine kinase (SYK) was identified as an oncogenic driver in a broad spectrum of hematologic malignancies. The in vivo comparison of three SYK containing oncogenes, SYKwt, TEL–SYK and IL-2-inducible T-cell kinase (ITK)-SYK revealed a general myeloexpansion and the establishment of three different hematologic (pre)diseases. SYKwt enhanced the myeloid and T-cell compartment, without leukemia/lymphoma development. ITK–SYK caused lethal T-cell lymphomas and the cytoplasmic TEL–SYK fusion induced an acute panmyelosis with myelofibrosis-type acute myeloid leukemia (AML) with up to 50% immature megakaryoblasts infiltrating bone marrow, spleen and liver, additional MPN features (myelofibrosis and granulocyte expansion) and MDS stigmata with megakaryocytic and erythroid dysplasia. LKS cells were reduced and all subsets (LT/ST/MPP) showed reduced proliferation rates. SYK inhibitor treatment (R788) of diseased TEL–SYK mice reduced leukocytosis, spleen and liver infiltration, enhanced the hematocrit and prolonged survival time, but could not significantly reduce myelofibrosis. Stat5 was identified as a major downstream mediator of TEL–SYK in vitro as well as in vivo. Consequently, targeted deletion of Stat5 in vivo completely abrogated TEL–SYK-induced AML and myelofibrosis development, proving Stat5 as a major driver of SYK-induced transformation. Our experiments highlight the important role of SYK in AML and myelofibrosis and prove SYK and STAT5 inhibitors as potent treatment options for those diseases.
PMCID: PMC4219468  PMID: 25148222
34.  Role of Bruton's tyrosine kinase (BTK) in growth and metastasis of INA6 myeloma cells 
Blood Cancer Journal  2014;4(8):e234-.
Bruton's tyrosine kinase (BTK) and the chemokine receptor CXCR4 are linked in various hematologic malignancies. The aim of the study was to understand the role of BTK in myeloma cell growth and metastasis using the stably BTK knockdown luciferase-expressing INA6 myeloma line. BTK knockdown had reduced adhesion to stroma and migration of myeloma cells toward stromal cell-derived factor-1. BTK knockdown had no effect on short-term in vitro growth of myeloma cells, although clonogenicity was inhibited and myeloma cell growth was promoted in coculture with osteoclasts. In severe combined immunodeficient-rab mice with contralaterally implanted pieces of bones, BTK knockdown in myeloma cells promoted their proliferation and growth in the primary bone but suppressed metastasis to the contralateral bone. BTK knockdown myeloma cells had altered the expression of genes associated with adhesion and proliferation and increased mammalian target of rapamycin signaling. In 176 paired clinical samples, BTK and CXCR4 expression was lower in myeloma cells purified from a focal lesion than from a random site. BTK expression in random-site samples was correlated with proportions of myeloma cells expressing cell surface CXCR4. Our findings highlight intratumoral heterogeneity of myeloma cells in the bone marrow microenvironment and suggest that BTK is involved in determining proliferative, quiescent or metastatic phenotypes of myeloma cells.
PMCID: PMC4219470  PMID: 25083818
36.  Clinical features and treatment outcome in newly diagnosed Chinese patients with multiple myeloma: results of a multicenter analysis 
Lu, J | Lu, J | Chen, W | Huo, Y | Huang, X | Hou, J
Blood Cancer Journal  2014;4(8):e239-.
The aim of this study was to understand the clinical features and treatment outcome of Chinese patients with multiple myeloma (MM). This retrospective study enrolled 940 newly diagnosed inpatients (median age, 59 years; immunoglobulin (Ig)D isotype, 6.5%) with complete follow-up data at three centers. In all, 85.8% of patients were of Durie-Salmon stage III and 48.3% were of International Staging System (ISS) stage III at diagnosis. Also, 9.6% of patients had extramedullary plasmacytoma. Compared with IgG, IgD-type patients were diagnosed at a younger age, and more patients were of ISS stage III, with hypercalcemia, elevated levels of lactate dehydrogenase, hyperuricemia, renal dysfunction and 1q21 amplification (P=0.03). The overall survival (OS) benefit was more prominent in IgG than in IgD when patients received bortezomib; however, they showed no significant difference when they received older therapies such as melphalan combined with prednisone or vincristine combined with adriamycin and dexamethasone. Fluorescence in situ hybridization (FISH) results showed that 17.6% had 17p13 deletion. Conventional cytogenetics revealed that 13.3% were hypodiploid and those cases had the worst survival, but hyperdiploid cases (9.3%) did not show any survival benefit compared with those with a normal karyotype (77.4%). Median OS and progression-free survival for all patients were 54 and 26 months, respectively. Significant factors for survival by multivariate analysis were gender, ISS stage, number of FISH abnormalities and extramedullary disease. MM in mainland China presents with different features, with patients being of younger age and having higher risk and more survival benefit in IgG patients receiving bortezomib.
PMCID: PMC4219472  PMID: 25127393
40.  Prognostic implications of CEBPA mutations in pediatric acute myeloid leukemia: a report from the Japanese Pediatric Leukemia/Lymphoma Study Group 
Blood Cancer Journal  2014;4(7):e226-.
CCAAT/enhancer-binding protein alpha (CEBPA) mutations are a favorable prognostic factor in adult acute myeloid leukemia (AML) patients; however, few studies have examined their significance in pediatric AML patients. Here we examined the CEBPA mutation status and clinical outcomes of pediatric AML patients treated in the AML-05 study. We found that 47 (14.9%) of the 315 evaluable patients harbored mutations in CEBPA; 26 cases (8.3%) harbored a single mutation (CEBPA-single) and 21 (6.7%) harbored double or triple mutations (CEBPA-double). After excluding core-binding factor-AML cases, patients harboring CEBPA mutations showed better overall survival (OS; P=0.048), but not event-free survival (EFS; P=0.051), than wild-type patients. Multivariate analysis identified CEBPA-single and CEBPA-double as independent favorable prognostic factors for EFS in the total cohort (hazard ratio (HR): 0.47 and 0.33; P=0.02 and 0.01, respectively). CEBPA-double was also an independent favorable prognostic factor for OS (HR: 0.30; P=0.04). CEBPA-double remained an independent favorable factor for EFS (HR: 0.28; P=0.04) in the normal karyotype cohort. These results suggest that CEBPA mutations, particularly CEBPA-double, are an independent favorable prognostic factor in pediatric AML patients, which will have important implications for risk-stratified therapy.
PMCID: PMC4219441  PMID: 25014773
41.  The glutathione synthesis inhibitor buthionine sulfoximine synergistically enhanced melphalan activity against preclinical models of multiple myeloma 
Blood Cancer Journal  2014;4(7):e229-.
Melphalan (L-PAM) has been an integral part of multiple myeloma (MM) treatment as a conditioning regimen before stem cell transplant (SCT). After initial response, most treated patients experience relapse with an aggressive phenotype. Increased glutathione (GSH) in MM may mediate resistance to L-PAM. We demonstrated that the GSH synthesis inhibitor buthionine sulfoximine (BSO) synergistically enhanced L-PAM activity (inducing 2–4 logs of cell kill) against nine MM cell lines (also in the presence of marrow stroma or cytokines) and in seven primary MM samples (combination indices <1.0). In MM cell lines, BSO significantly (P<0.05) depleted GSH, increased L-PAM-induced single-strand DNA breaks, mitochondrial depolarization, caspase cleavage and apoptosis. L-PAM depleted GSH, but GSH rapidly recovered in a L-PAM-resistant MM cell line unless also treated with BSO. Treatment with N-acetylcysteine antagonized BSO+L-PAM cytotoxicity without increasing GSH. In human MM xenografted into beige-nude-xid mice, BSO significantly depleted MM intracellular GSH and significantly increased apoptosis compared with L-PAM alone. BSO+L-PAM achieved complete responses (CRs) in three MM xenograft models including maintained CRs >100 days, and significantly increased the median event-free survival relative to L-PAM alone. Combining BSO with L-PAM warrants clinical testing in advanced MM.
PMCID: PMC4219442  PMID: 25036800
42.  Human HMGA2 protein overexpressed in mice induces precursor T-cell lymphoblastic leukemia 
Blood Cancer Journal  2014;4(7):e227-.
T-cell acute lymphoblastic leukemia (T-ALL) is a neoplasia of thymocytes characterized by the rapid accumulation of the precursors of T lymphocytes. HMGA2 (high-mobility group AT-hook 2) gene expression is extremely low in normal adult tissues, but it is overexpressed in many tumors. To identify the biological function of HMGA2, we generated transgenic mice carrying the human HMGA2 gene under control of the VH promoter/Eμ enhancer. Approximately 90% of Eμ-HMGA2 transgenic mice became visibly sick between 4 and 8 months due to the onset and progression of a T-ALL-like disease. Characteristic features included severe alopecia (30% of mice); enlarged lymph nodes and spleen; and profound immunological abnormalities (altered cytokine levels, hypoimmunoglobulinemia) leading to reduced immune responsiveness. Immunophenotyping showed accumulation of CD5+CD4+, CD5+CD8+ or CD5+CD8+CD4+ T-cell populations in the spleens and bone marrow of sick animals. These findings show that HMGA2-driven leukemia in mice closely resembles spontaneous human T-ALL, indicating that HMGA2 transgenic mice should serve as an important model for investigating basic mechanisms and potential new therapies of relevance to human T-ALL.
PMCID: PMC4219444  PMID: 25014774
47.  Notch pathway inhibition controls myeloma bone disease in the murine MOPC315.BM model 
Blood Cancer Journal  2014;4(6):e217-.
Despite evidence that deregulated Notch signalling is a master regulator of multiple myeloma (MM) pathogenesis, its contribution to myeloma bone disease remains to be resolved. Notch promotes survival of human MM cells and triggers human osteoclast activity in vitro. Here, we show that inhibition of Notch through the γ-secretase inhibitor XII (GSI XII) induces apoptosis of murine MOPC315.BM myeloma cells with high Notch activity. GSI XII impairs murine osteoclast differentiation of receptor activator of NF-κB ligand (RANKL)-stimulated RAW264.7 cells in vitro. In the murine MOPC315.BM myeloma model GSI XII has potent anti-MM activity and reduces osteolytic lesions as evidenced by diminished myeloma-specific monoclonal immunoglobulin (Ig)-A serum levels and quantitative assessment of bone structure changes via high-resolution microcomputed tomography scans. Thus, we suggest that Notch inhibition through GSI XII controls myeloma bone disease mainly by targeting Notch in MM cells and possibly in osteoclasts in their microenvironment. We conclude that Notch inhibition is a valid therapeutic strategy in MM.
PMCID: PMC4080208  PMID: 24927406
48.  The novel immunotoxin HM1.24-ETA′ induces apoptosis in multiple myeloma cells 
Blood Cancer Journal  2014;4(6):e219-.
Despite new treatment modalities, the clinical outcome in a substantial number of patients with multiple myeloma (MM) has yet to be improved. Antibody-based targeted therapies for myeloma patients could make use of the HM1.24 antigen (CD317), a surface molecule overexpressed on malignant plasma cells and efficiently internalized. Here, a novel immunotoxin, HM1.24-ETA′, is described. HM1.24-ETA′ was generated by genetic fusion of a CD317-specific single-chain Fv (scFv) antibody and a truncated variant of Pseudomonas aeruginosa exotoxin A (ETA′). HM1.24-ETA′ inhibited growth of interleukin 6 (IL-6)-dependent and -independent myeloma cell lines. Half-maximal growth inhibition was observed at concentrations as low as 0.3 nM. Target cell killing occurred via induction of apoptosis and was unaffected in co-culture experiments with bone marrow stromal cells. HM1.24-ETA′ efficiently triggered apoptosis of freshly isolated/cryopreserved cells of patients with plasma cell leukemia and MM and was active in a preclinical severe combined immunodeficiency (SCID) mouse xenograft model. Importantly, HM1.24-ETA′ was not cytotoxic against CD317-positive cells from healthy tissue (monocytes, human umbilical vein endothelial cells). These results indicate that CD317 may represent a promising target structure for specific and efficient immunotoxin therapy for patients with plasma cell tumors.
PMCID: PMC4080209  PMID: 24927408
49.  Distribution and levels of cell surface expression of CD33 and CD123 in acute myeloid leukemia 
Blood Cancer Journal  2014;4(6):e218-.
Owing to the more recent positive results with the anti-CD33 immunotoxin gemtuzumab ozogamicin, therapy against acute myeloid leukemias (AMLs) targeting CD33 holds many promises. Here, CD33 and CD123 expression on AML blasts was studied by flow cytometry in a cohort of 319 patients with detailed information on French–American–British/World Health Organization (FAB/WHO) classification, cytogenetics and molecular aberrations. AMLs of 87.8% express CD33 and would therefore be targetable with anti-CD33 therapies. Additionally, 9.4% of AMLs express CD123 without concomitant CD33 expression. Thus, nearly all AMLs could be either targeted via CD33 or CD123. Simultaneous presence of both antigens was observed in 69.5% of patients. Most importantly, even AMLs with adverse cytogenetics express CD33 and CD123 levels comparable to those with favorable and intermediate subtypes. Some patient groups with unfavorable alterations, such as FMS-related tyrosine kinase 3-internal tandem duplication (FLT3-ITD) mutations, high FLT3-ITD mutant/wild-type ratios and monosomy 5 are even characterized by high expression of CD33 and CD123. In addition, blasts of patients with mutant nucleophosmin (NPM1) revealed significantly higher CD33 and CD123 expression pointing toward the possibility of minimal residual disease-guided interventions in mutated NPM1-positive AMLs. These results stimulate the development of novel concepts to redirect immune effector cells toward CD33- and CD123-expressing blasts using bi-specific antibodies or engineered T cells expressing chimeric antigen receptors.
PMCID: PMC4080210  PMID: 24927407
50.  Helicobacter pylori-related diffuse large B-cell lymphoma of the stomach: a distinct entity with lower aggressiveness and higher chemosensitivity 
Blood Cancer Journal  2014;4(6):e220-.
We recently showed that Helicobacter pylori (HP)-positive gastric ‘pure' diffuse large B-cell lymphoma (DLBCL) may respond to HP eradication therapy. However, whether these HP-related ‘pure' DLBCL of the stomach may differ fundamentally from those unrelated to HP remains unclear. In this study, we compared the clinicopathologic features of these two groups of patients who had been uniformly treated by conventional chemotherapy. Forty-six patients were designated HP-positive and 49 were HP-negative by conventional criteria. HP-positive patients had a lower International Prognostic Index score (0–1, 65% vs 43%, P=0.029), a lower clinical stage (I-IIE1, 70% vs 39%, P=0.003), a better tumor response to chemotherapy (complete pathologic response, 76% vs 47%, P=0.004) and significantly superior 5-year event-free survival (EFS) (71.7% vs 31.8%, P<0.001) and overall survival (OS) (76.1% vs 39.8%, P<0.001). To draw a closer biologic link with HP, HP-positive tumors were further examined for CagA expression in lymphoma cells. Compared with CagA-negative cases (n=16), CagA-positive cases (n=27) were associated with high phosphorylated SHP-2 expression (P=0.016), and even better 5-year EFS (85.2% vs 46.3%, P=0.002) and OS (88.9% vs 52.9%, P=0.003). HP-related gastric ‘pure' DLBCL may be a distinct tumor entity, which is less aggressive, and responds better to conventional chemotherapy.
PMCID: PMC4080211  PMID: 24949857

Results 26-50 (266)