Leukemia patient-derived lymphoblastoid cell lines exhibit increased induction of leukemia-associated transcripts following high-dose irradiation.

PubMed

Spencer, A; Granter, N

1999-09-01

Improvement in diagnostic cytogenetic techniques has led to the recognition of an increasing number of leukemia-associated chromosomal translocations and inversions. These genetic lesions frequently are associated with the disruption of putative transcription factors and the production of hybrid transcripts that are implicated in leukemogenesis. Epidemiologic evidence suggests that some, but not all, individuals with a history of gamma-irradiation exposure are at increased risk of developing chronic myeloid leukemia (CML). CML is characterized by the Philadelphia chromosome and transcription of the resulting hybrid BCR-ABL gene. Utilizing the leukemia-associated BCR-ABL p210 transcript as a marker, we sought differences in the induction of illegitimate genetic recombination following high-dose gamma-irradiation of karyotypically normal lymphoblastoid cell lines (LCL) derived from individuals with and without a history of myeloid leukemias. Six LCL [4 leukemia patient derived [2 acute myeloid leukemia and 2 CML] and 2 from normal individuals were analyzed with reverse transcriptase polymerase chain reaction for BCR-ABL under stringent conditions following exposure to 0, 50, or 100 Gy of LET gamma-irradiation delivered via a Varian linear accelerator at 4 MV. Transcripts identical to disease-associated b2a2 and b3a2 transcripts were detected both spontaneously (background illegitimate genetic recombination) and following gamma-irradiation. Background BCR-ABL positivity was demonstrable in 4 of the 6 LCL, with no significant difference in detection between leukemic- and nonleukemic-derived LCL. Overall, increasing gamma-irradiation dose resulted in an increased frequency of BCR-ABL transcript detection (0 Gy vs 50 Gy vs 100 Gy,p = 0.0023, Chi-square test). Within the leukemic- but not the nonleukemic-derived LCL there was significantly greater BCR-ABL positivity after gamma-irradiation compared to unirradiated equivalents. Furthermore, the BCR-ABL positivity of both the AML- and CML-derived LCL after gamma-irradiation was significantly greater than that of the nonleukemic-derived LCL after gamma-irradiation. We speculate that this difference in the detection of illegitimate after gamma-irradiation recombination may be due to aberrant DNA double strand break repair mechanisms in individuals predisposed to the development of myeloid leukemias.

In chronic myeloid leukemia patients on second-line tyrosine kinase inhibitor therapy, deep sequencing of BCR-ABL1 at the time of warning may allow sensitive detection of emerging drug-resistant mutants.

PubMed

Soverini, Simona; De Benedittis, Caterina; Castagnetti, Fausto; Gugliotta, Gabriele; Mancini, Manuela; Bavaro, Luana; Machova Polakova, Katerina; Linhartova, Jana; Iurlo, Alessandra; Russo, Domenico; Pane, Fabrizio; Saglio, Giuseppe; Rosti, Gianantonio; Cavo, Michele; Baccarani, Michele; Martinelli, Giovanni

2016-08-02

Imatinib-resistant chronic myeloid leukemia (CML) patients receiving second-line tyrosine kinase inhibitor (TKI) therapy with dasatinib or nilotinib have a higher risk of disease relapse and progression and not infrequently BCR-ABL1 kinase domain (KD) mutations are implicated in therapeutic failure. In this setting, earlier detection of emerging BCR-ABL1 KD mutations would offer greater chances of efficacy for subsequent salvage therapy and limit the biological consequences of full BCR-ABL1 kinase reactivation. Taking advantage of an already set up and validated next-generation deep amplicon sequencing (DS) assay, we aimed to assess whether DS may allow a larger window of detection of emerging BCR-ABL1 KD mutants predicting for an impending relapse. a total of 125 longitudinal samples from 51 CML patients who had acquired dasatinib- or nilotinib-resistant mutations during second-line therapy were analyzed by DS from the time of failure and mutation detection by conventional sequencing backwards. BCR-ABL1/ABL1%(IS) transcript levels were used to define whether the patient had 'optimal response', 'warning' or 'failure' at the time of first mutation detection by DS. DS was able to backtrack dasatinib- or nilotinib-resistant mutations to the previous sample(s) in 23/51 (45 %) pts. Median mutation burden at the time of first detection by DS was 5.5 % (range, 1.5-17.5 %); median interval between detection by DS and detection by conventional sequencing was 3 months (range, 1-9 months). In 5 cases, the mutations were detectable at baseline. In the remaining cases, response level at the time mutations were first detected by DS could be defined as 'Warning' (according to the 2013 ELN definitions of response to 2nd-line therapy) in 13 cases, as 'Optimal response' in one case, as 'Failure' in 4 cases. No dasatinib- or nilotinib-resistant mutations were detected by DS in 15 randomly selected patients with 'warning' at various timepoints, that later turned into optimal responders with no treatment changes. DS enables a larger window of detection of emerging BCR-ABL1 KD mutations predicting for an impending relapse. A 'Warning' response may represent a rational trigger, besides 'Failure', for DS-based mutation screening in CML patients undergoing second-line TKI therapy.

Identification of e6a2 BCR-ABL fusion in a Philadelphia-positive CML with marked basophilia: implications for treatment strategy.

PubMed

Rohon, Peter; Divoka, Martina; Calabkova, Lenka; Mojzikova, Renata; Katrincsakova, Beata; Rusinakova, Zuzana; Lapcikova, Anna; Raida, Ludek; Faber, Edgar; Jarosova, Marie; Divoky, Vladimir; Indrak, Karel

2011-06-01

This is a case report of a 51 year old male with marked splenomegaly, basophilia, severe thrombocytopenia, anemia and high SFKL phosphorylation downstream of Bcr-Abl, investigated for association of the e6a2 BCR-ABL fusion gene and marked basophilia. The treatment strategy implications in patients with Philadelphia positive CML are described. RT-PCR and sequencing were carried out on the peripheral blood leukocytes to detect the type of BCR-ABL transcript. The BCR-ABL mutational status was assessed using sequencing of the RT-PCR products. The in vitro test of sensitivity to TKIs was based on detecting inhibited phosphorylation of the Crkl and Phospho-Src family kinases (SFK, Tyr416) using immunodetection. The cytogenetics revealed 90% of Ph+ (Philadelphia) cells in the bone marrow aspirate with no additional clonal chromosomal abnormalities at diagnosis. This correlated with an accelerated phase of the CML. Sequencing analysis of reverse transcribed and PCR amplified BCR-ABL transcript revealed a rare e6a2 fusion, with no evidence for Bcr-Abl kinase domain mutation. Western blot analysis showed high phosphorylation (activation) of Crkl and the Src family of kinases (P-SFK). In vitro test of sensitivity of the patients' leukemic cells to imatinib demonstrated sensitivity of Bcr-Abl tyrosine kinase to imatinib, as assessed by a decrease in phosphorylated Crkl and the disappearance of P-SFK, suggesting that P-Src reflects only the Bcr-Abl-dependent Src activity. The initial treatment strategy was reduced imatinib and search for an unrelated hematopoietic stem cell donor (according to the ELN recommendations). The patient was allografted with peripheral stem cells from an HLA- identical male donor but on day +70 graft failure occurred. He was allografted again with the peripheral stem cells from an HLA-identical female donor, engrafted on day +15 and showed 100% donor chimerism with no evidence of the e6a2 BCR-ABL fusion transcript on day +30. The clinical disease course in patients with the rare e6a2 BCR-ABL transcript variant is aggressive. This may be the result of increased kinase activity due to partial loss of the guanine exchange factor/dbl-like domain which mediates the interaction with several Ras-like G-proteins involved in cell proliferation, signal transduction, and cytoskeletal organization. For the above reasons, these patients should receive stem cell transplant immediately after a short course of treatment with imatinib/ dual Src/Abl kinase inhibitor or they should be registered in clinical trials with experimental agents.

Genetic analysis of Ikaros target genes and tumor suppressor function in BCR-ABL1+ pre–B ALL

PubMed Central

Aghajanirefah, Ali; McLaughlin, Jami; Cheng, Donghui; Geng, Huimin; Eggesbø, Linn M.; Smale, Stephen T.; Müschen, Markus

2017-01-01

Inactivation of the tumor suppressor gene encoding the transcriptional regulator Ikaros (IKZF1) is a hallmark of BCR-ABL1+ precursor B cell acute lymphoblastic leukemia (pre–B ALL). However, the mechanisms by which Ikaros functions as a tumor suppressor in pre–B ALL remain poorly understood. Here, we analyzed a mouse model of BCR-ABL1+ pre–B ALL together with a new model of inducible expression of wild-type Ikaros in IKZF1 mutant human BCR-ABL1+ pre–B ALL. We performed integrated genome-wide chromatin and expression analyses and identified Ikaros target genes in mouse and human BCR-ABL1+ pre–B ALL, revealing novel conserved gene pathways associated with Ikaros tumor suppressor function. Notably, genetic depletion of different Ikaros targets, including CTNND1 and the early hematopoietic cell surface marker CD34, resulted in reduced leukemic growth. Our results suggest that Ikaros mediates tumor suppressor function by enforcing proper developmental stage–specific expression of multiple genes through chromatin compaction at its target genes. PMID:28190001

Role of flow-cytometric immunophenotyping in prediction of BCR/ABL1 gene rearrangement in adult B-cell acute lymphoblastic leukemia.

PubMed

Corrente, Francesco; Bellesi, Silvia; Metafuni, Elisabetta; Puggioni, Pier Luigi; Marietti, Sara; Ciminello, Angela Maria; Za, Tommaso; Sorà, Federica; Fianchi, Luana; Sica, Simona; De Stefano, Valerio; Chiusolo, Patrizia

2018-05-01

We performed a retrospective analysis of 88 adult patients with B-ALL diagnosed in our center by a flow-cytometric assessment. Immunophenotypic expression of leukemic cells was explored by simultaneous evaluation of positivity, percentage of expressing cells and median fluorescence intensity (MFI). BCR/ABL1 fusion transcripts were assessed by RT-PCR analysis and were identified in 36 patients (40.9%). CD10 and CD34 were positive in the totality of BCR/ABL1-positive cases. Patients with gene rearrangement had a greater frequency of CD66c, CD13 and CD33 positivity compared with BCR/ABL1-negative cases. Moreover, BCR/ABL1-positive cases exhibited a greater median percentage and MFI values of CD13, CD33, CD66c, CD10, CD34 and CD25 expressions, but a lower median percentage and MFI values of CD38 and CD22 expressions than patients without gene rearrangement. Multivariate logistic regression analysis showed that CD10, CD38 and CD13 expressions were independent predictors for the presence of BCR/ABL1 rearrangement. Predictive probabilities of molecular occurrence based on these markers are proposed. © 2017 International Clinical Cytometry Society. © 2017 International Clinical Cytometry Society.

Activation of EVI1 transcription by the LEF1/β-catenin complex with p53-alteration in myeloid blast crisis of chronic myeloid leukemia.

PubMed

Manachai, Nawin; Saito, Yusuke; Nakahata, Shingo; Bahirvani, Avinash Govind; Osato, Motomi; Morishita, Kazuhiro

2017-01-22

The presence of a BCR-ABL1 fusion gene is necessary for the pathogenesis of chronic myeloid leukemia (CML) through t(9;22)(q34;q11) translocation. Imatinib, an ABL tyrosine kinase inhibitor, is dramatically effective in CML patients; however, 30% of CML patients will need further treatment due to progression of CML to blast crisis (BC). Aberrant high expression of ecotropic viral integration site 1 (EVI1) is frequently observed in CML during myeloid-BC as a potent driver with a CML stem cell signature; however, the precise molecular mechanism of EVI1 transcriptional regulation during CML progression is poorly defined. Here, we demonstrate the transcriptional activity of EVI1 is dependent on activation of lymphoid enhancer-binding factor 1 (LEF1)/β-catenin complex by BCR-ABL with loss of p53 function during CML-BC. The activation of β-catenin is partly dependent on BCR-ABL expression through enhanced GSK3β phosphorylation, and EVI1 expression is directly enhanced by the LEF1/β-catenin complex bound to the EVI1 promoter region. Moreover, the loss of p53 expression is inversely correlated with high expression of EVI1 in CML leukemia cells with an aggressive phase of CML, and a portion of the activation mechanism of EVI1 expression is dependent on β-catenin activation through GSK3β phosphorylation by loss of p53. Therefore, we found that the EVI1 activation in CML-BC is dependent on LEF1/β-catenin activation by BCR-ABL expression with loss of p53 function, representing a novel selective therapeutic approach targeting myeloid blast crisis progression. Copyright © 2016 Elsevier Inc. All rights reserved.

BCR-ABL1 Compound Mutations Combining Key Kinase Domain Positions Confer Clinical Resistance to Ponatinib in Ph Chromosome-Positive Leukemia

PubMed Central

Zabriskie, Matthew S.; Eide, Christopher A.; Tantravahi, Srinivas K.; Vellore, Nadeem A.; Estrada, Johanna; Nicolini, Franck E.; Khoury, Hanna J.; Larson, Richard A.; Konopleva, Marina; Cortes, Jorge E.; Kantarjian, Hagop; Jabbour, Elias J.; Kornblau, Steven M.; Lipton, Jeffrey H.; Rea, Delphine; Stenke, Leif; Barbany, Gisela; Lange, Thoralf; Hernández-Boluda, Juan-Carlos; Ossenkoppele, Gert J.; Press, Richard D.; Chuah, Charles; Goldberg, Stuart L.; Wetzler, Meir; Mahon, Francois-Xavier; Etienne, Gabriel; Baccarani, Michele; Soverini, Simona; Rosti, Gianantonio; Rousselot, Philippe; Friedman, Ran; Deininger, Marie; Reynolds, Kimberly R.; Heaton, William L.; Eiring, Anna M.; Pomicter, Anthony D.; Khorashad, Jamshid S.; Kelley, Todd W.; Baron, Riccardo; Druker, Brian J.; Deininger, Michael W.; O'Hare, Thomas

2014-01-01

Summary Ponatinib is the only currently approved tyrosine kinase inhibitor (TKI) that suppresses all BCR-ABL1 single mutants in Philadelphia chromosome-positive (Ph+) leukemia, including the recalcitrant BCR-ABL1T315I mutant. However, emergence of compound mutations in a BCR-ABL1 allele may confer ponatinib resistance. We found that clinically reported BCR-ABL1 compound mutants center on 12 key positions and confer varying resistance to imatinib, nilotinib, dasatinib, ponatinib, rebastinib and bosutinib. T315I-inclusive compound mutants confer high-level resistance to TKIs, including ponatinib. In vitro resistance profiling was predictive of treatment outcomes in Ph+ leukemia patients. Structural explanations for compound mutation-based resistance were obtained through molecular dynamics simulations. Our findings demonstrate that BCR-ABL1 compound mutants confer different levels of TKI resistance, necessitating rational treatment selection to optimize clinical outcome. PMID:25132497

Novel Combined Ato-C Treatment Synergistically Suppresses Proliferation of Bcr-Abl-Positive Leukemic Cells In Vitro and In Vivo.

PubMed

Wahiduzzaman, Md; Ota, Akinobu; Karnan, Sivasundaram; Hanamura, Ichiro; Mizuno, Shohei; Kanasugi, Jo; Rahman, Md Lutfur; Hyodo, Toshinori; Konishi, Hiroyuki; Tsuzuki, Shinobu; Takami, Akiyoshi; Hosokawa, Yoshitaka

2018-06-23

Chronic myelogenous leukemia (CML) accounts for 15-20% of all leukemias affecting adults. Despite recent advances in the development of specific Bcr-Abl tyrosine kinase inhibitors (TKIs), some CML patients suffer from relapse due to TKI resistance. Here, we assessed the efficacy of a novel combinatorial arsenic trioxide (ATO) and cisplatin (CDDP) treatment (Ato-C) in human Bcr-Abl-positive leukemic cells. Combination index analyses revealed that a synergistic interaction of ATO and CDDP elicits a wide range of effects in K562, KU-812, MEG-A2, and KCL-22 cells. Notably, Ato-C synergistically enhanced apoptosis and decreased the survival of both acquired TKI-resistant CML cells and the cells expressing mutant Bcr-Abl T315I . In addition, Ato-C dramatically decreased the phosphorylation level of forkhead transcription factor FOXO1/3a and STAT5 as well as c-Myc protein level. Interestingly, results of gene set enrichment analysis showed that Ato-C significantly downregulates the expression of MYC- and/or E2F1-targets genes. Furthermore, Ato-C significantly suppressed the proliferation of MEG-A2-derived tumor when compared with that following monotherapy in vivo. Collectively, these results suggest that combined Ato-C treatment could be a promising alternative to the current therapeutic regime in CML. Copyright © 2018. Published by Elsevier B.V.

The transcription factor IRF8 counteracts BCR-ABL to rescue dendritic cell development in chronic myelogenous leukemia.

PubMed

Watanabe, Tomoya; Hotta, Chie; Koizumi, Shin-ichi; Miyashita, Kazuho; Nakabayashi, Jun; Kurotaki, Daisuke; Sato, Go R; Yamamoto, Michio; Nakazawa, Masatoshi; Fujita, Hiroyuki; Sakai, Rika; Fujisawa, Shin; Nishiyama, Akira; Ikezawa, Zenro; Aihara, Michiko; Ishigatsubo, Yoshiaki; Tamura, Tomohiko

2013-11-15

BCR-ABL tyrosine kinase inhibitors (TKI) have dramatically improved therapy for chronic myelogenous leukemia (CML). However, several problems leading to TKI resistance still impede a complete cure of this disease. IFN regulatory factor-8 (IRF8) is a transcription factor essential for the development and functions of immune cells, including dendritic cells. Irf8(-/-) mice develop a CML-like disease and IRF8 expression is downregulated in patients with CML, suggesting that IRF8 is involved in the pathogenesis of CML. In this study, by using a murine CML model, we show that BCR-ABL strongly inhibits a generation of dendritic cells from an early stage of their differentiation in vivo, concomitant with suppression of Irf8 expression. Forced expression of IRF8 overrode BCR-ABL (both wild-type and T315I-mutated) to rescue dendritic cell development in vitro, indicating that the suppression of Irf8 causes dendritic cell deficiency. Gene expression profiling revealed that IRF8 restored the expression of a significant portion of BCR-ABL-dysregulated genes and predicted that BCR-ABL has immune-stimulatory potential. Indeed, IRF8-rescued BCR-ABL-expressing dendritic cells were capable of inducing CTLs more efficiently than control dendritic cells. Altogether, our findings suggest that IRF8 is an attractive target in next-generation therapies for CML. ©2013 AACR

Activation of EVI1 transcription by the LEF1/β-catenin complex with p53-alteration in myeloid blast crisis of chronic myeloid leukemia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manachai, Nawin; Saito, Yusuke; Nakahata, Shingo

The presence of a BCR-ABL1 fusion gene is necessary for the pathogenesis of chronic myeloid leukemia (CML) through t(9;22)(q34;q11) translocation. Imatinib, an ABL tyrosine kinase inhibitor, is dramatically effective in CML patients; however, 30% of CML patients will need further treatment due to progression of CML to blast crisis (BC). Aberrant high expression of ecotropic viral integration site 1 (EVI1) is frequently observed in CML during myeloid-BC as a potent driver with a CML stem cell signature; however, the precise molecular mechanism of EVI1 transcriptional regulation during CML progression is poorly defined. Here, we demonstrate the transcriptional activity of EVI1more » is dependent on activation of lymphoid enhancer-binding factor 1 (LEF1)/β-catenin complex by BCR-ABL with loss of p53 function during CML-BC. The activation of β-catenin is partly dependent on BCR-ABL expression through enhanced GSK3β phosphorylation, and EVI1 expression is directly enhanced by the LEF1/β-catenin complex bound to the EVI1 promoter region. Moreover, the loss of p53 expression is inversely correlated with high expression of EVI1 in CML leukemia cells with an aggressive phase of CML, and a portion of the activation mechanism of EVI1 expression is dependent on β-catenin activation through GSK3β phosphorylation by loss of p53. Therefore, we found that the EVI1 activation in CML-BC is dependent on LEF1/β-catenin activation by BCR-ABL expression with loss of p53 function, representing a novel selective therapeutic approach targeting myeloid blast crisis progression. - Highlights: • Transcriptional regulation of EVI1 in CML-BC is proposed. • EVI1 transcription is directly regulated by LEF1/β-catenin complex in CML-BC. • Loss of p53 function as a key regulator for β-catenin-EVI1 in CML myeloid-BC. • The LEF1/β-catenin binding site on the EVI1 promoter is a new target for CML-BC.« less

Prevalence of the BCR/ABL1 transcripts in Mexican patients with chronic myelogenous leukemia.

PubMed

Meza-Espinoza, Juan Pablo; Gutiérrez-Angulo, Melva; Vázquez-Cárdenas, Alejandra; Delgado-Lamas, José Luis; Esparza-Flores, María Amparo; González-García, Juan Ramón

2007-01-01

RT-PCR studies in 93 patients with chronic myelogenous leukemia from the Mexican West were done in order to know the proportion of b2a2 and b3a2 BCR/ABL1 transcripts. Forty-five patients showed the b3a2 transcript (48%), 37 (40%) displayed the b2a2 and in 11 cases (12%) both transcripts were detected. Statistical analyses showed that these figures are in accordance with two of three similar studies realized in Mexican population. Moreover, significant differences were found among Mexican people and patients from other countries, namely Ecuador, England, Italy, Poland, Japan, and Thailand. Ecuadorian patients showed differences with all the populations analyzed. These variations could be due to a different genetic background.

Development of protein degradation inducers of oncogenic BCR-ABL protein by conjugation of ABL kinase inhibitors and IAP ligands.

PubMed

Shibata, Norihito; Miyamoto, Naoki; Nagai, Katsunori; Shimokawa, Kenichiro; Sameshima, Tomoya; Ohoka, Nobumichi; Hattori, Takayuki; Imaeda, Yasuhiro; Nara, Hiroshi; Cho, Nobuo; Naito, Mikihiko

2017-08-01

Chromosomal translocation occurs in some cancer cells, which results in the expression of aberrant oncogenic fusion proteins that include BCR-ABL in chronic myelogenous leukemia (CML). Inhibitors of ABL tyrosine kinase, such as imatinib and dasatinib, exhibit remarkable therapeutic effects, although emergence of drug resistance hampers the therapy during long-term treatment. An alternative approach to treat CML is to downregulate the BCR-ABL protein. We have devised a protein knockdown system by hybrid molecules named Specific and Non-genetic inhibitor of apoptosis protein [IAP]-dependent Protein Erasers (SNIPER), which is designed to induce IAP-mediated ubiquitylation and proteasomal degradation of target proteins, and a couple of SNIPER(ABL) against BCR-ABL protein have been developed recently. In this study, we tested various combinations of ABL inhibitors and IAP ligands, and the linker was optimized for protein knockdown activity of SNIPER(ABL). The resulting SNIPER(ABL)-39, in which dasatinib is conjugated to an IAP ligand LCL161 derivative by polyethylene glycol (PEG) × 3 linker, shows a potent activity to degrade the BCR-ABL protein. Mechanistic analysis suggested that both cellular inhibitor of apoptosis protein 1 (cIAP1) and X-linked inhibitor of apoptosis protein (XIAP) play a role in the degradation of BCR-ABL protein. Consistent with the degradation of BCR-ABL protein, the SNIPER(ABL)-39 inhibited the phosphorylation of signal transducer and activator of transcription 5 (STAT5) and Crk like proto-oncogene (CrkL), and suppressed the growth of BCR-ABL-positive CML cells. These results suggest that SNIPER(ABL)-39 could be a candidate for a degradation-based novel anti-cancer drug against BCR-ABL-positive CML. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Targeting of the BLT2 in chronic myeloid leukemia inhibits leukemia stem/progenitor cell function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiao, Meifang; Ai, Hongmei; Li, Tao

Imatinib, a tyrosine kinase inhibitor (TKI) has significantly improved clinical outcome for chronic myeloid leukemia (CML) patients. However, patients develop resistance when the disease progresses to the blast phase (BP) and the mechanisms are not well understood. Here we show that BCR-ABL activates BLT2 in hematopoietic stem/progenitor cells to promote leukemogenesis and this involves the p53 signaling pathway. Compared to normal bone marrow (NBM), the mRNA and protein levels of BLT2 are significantly increased in BP-CML CD34{sup +} stem/progenitor cells. This is correlated with increasing BCR-ABL expression. In contrast, knockdown of BCR-ABL or inhibition of its tyrosine kinase activity decreasesmore » Blt2 protein level. BLT2 inhibition induces apoptosis, inhibits proliferation, colony formation and self-renewal capacity of CD34{sup +} cells from TKI-resistant BP-CML patients. Importantly, the inhibitory effects of BCR-ABL TKI on CML stem/progenitor cells are further enhanced upon combination with BLT2 inhibition. We further show that BLT2 activation selectively suppresses p53 but not Wnt or BMP-mediated luciferase activity and transcription. Our results demonstrate that BLT2 is a novel pathway activated by BCR-ABL and critically involved in the resistance of BP-CML CD34{sup +} stem/progenitors to TKIs treatment. Our findings suggest that BLT2 and p53 can serve as therapeutic targets for CML treatment. - Highlights: • BCR-ABL regulates BLT2 expression to promote leukemogenesis. • BLT2 is essential to maintain CML cell function. • Activation of BLT2 suppresses p53 signaling pathway in CML cells. • Inhibition of BLT2 and BCR-ABL synergize in eliminating CML CD34{sup +} stem/progenitors.« less

How is the relationship between TWIST-1 and BCR-ABL1 gene expressions in chronic myeloid leukaemia patients?

PubMed

Heidari, Nazanin; Vosoughi, Tina; Mohammadi Asl, Javad; Saki Malehi, Amal; Saki, Najmaldin

2018-01-12

The activation and increased expression of BCR-ABL1 lead to malignant chronic myelogenous leukaemia (CML) cells, as well as the resistance to antitumour agents and apoptosis inducers. Moreover, TWIST-1 protein is a prognostic factor of leukemogenesis, and its level is raised in CML patients with cytogenetic resistance to imatinib. So, there is a likely relationship between BCR-ABL1 and TWIST-1 genes. The aim of the study was to assess the relationship between TWIST-1 and BCR-ABL1 expressions. Peripheral blood samples were obtained from 44 CML patients under treatment and also from ten healthy subjects as normal controls. The expression of TWIST-1 and BCR-ABL1 genes was measured using real-time PCR, and ABL1 was used as the reference gene. The gene expression was evaluated by REST software. The expression levels of TWIST-1 and BCR-ABL1 genes in CML patients was changed 40.23 ± 177.75-fold and 6 ± 18-fold, respectively. No significant relationship was observed between the expressions of TWIST-1 and BCR-ABL1 genes. All patients with TWIST-1 expression levels ≥100-fold had failure of response to treatment. The probability of the relationship between BCR-ABL1 and TWIST-1 is still debatable, and the average of TWIST-1 expression has been higher in patients without response to treatment. Definitive conclusion needs further investigations.

BCR-ABL1 compound mutations combining key kinase domain positions confer clinical resistance to ponatinib in Ph chromosome-positive leukemia.

PubMed

Zabriskie, Matthew S; Eide, Christopher A; Tantravahi, Srinivas K; Vellore, Nadeem A; Estrada, Johanna; Nicolini, Franck E; Khoury, Hanna J; Larson, Richard A; Konopleva, Marina; Cortes, Jorge E; Kantarjian, Hagop; Jabbour, Elias J; Kornblau, Steven M; Lipton, Jeffrey H; Rea, Delphine; Stenke, Leif; Barbany, Gisela; Lange, Thoralf; Hernández-Boluda, Juan-Carlos; Ossenkoppele, Gert J; Press, Richard D; Chuah, Charles; Goldberg, Stuart L; Wetzler, Meir; Mahon, Francois-Xavier; Etienne, Gabriel; Baccarani, Michele; Soverini, Simona; Rosti, Gianantonio; Rousselot, Philippe; Friedman, Ran; Deininger, Marie; Reynolds, Kimberly R; Heaton, William L; Eiring, Anna M; Pomicter, Anthony D; Khorashad, Jamshid S; Kelley, Todd W; Baron, Riccardo; Druker, Brian J; Deininger, Michael W; O'Hare, Thomas

2014-09-08

Ponatinib is the only currently approved tyrosine kinase inhibitor (TKI) that suppresses all BCR-ABL1 single mutants in Philadelphia chromosome-positive (Ph(+)) leukemia, including the recalcitrant BCR-ABL1(T315I) mutant. However, emergence of compound mutations in a BCR-ABL1 allele may confer ponatinib resistance. We found that clinically reported BCR-ABL1 compound mutants center on 12 key positions and confer varying resistance to imatinib, nilotinib, dasatinib, ponatinib, rebastinib, and bosutinib. T315I-inclusive compound mutants confer high-level resistance to TKIs, including ponatinib. In vitro resistance profiling was predictive of treatment outcomes in Ph(+) leukemia patients. Structural explanations for compound mutation-based resistance were obtained through molecular dynamics simulations. Our findings demonstrate that BCR-ABL1 compound mutants confer different levels of TKI resistance, necessitating rational treatment selection to optimize clinical outcome. Copyright © 2014 Elsevier Inc. All rights reserved.

Monitoring of childhood ALL using BCR-ABL1 genomic breakpoints identifies a subgroup with CML-like biology.

PubMed

Hovorkova, Lenka; Zaliova, Marketa; Venn, Nicola C; Bleckmann, Kirsten; Trkova, Marie; Potuckova, Eliska; Vaskova, Martina; Linhartova, Jana; Machova Polakova, Katerina; Fronkova, Eva; Muskovic, Walter; Giles, Jodie E; Shaw, Peter J; Cario, Gunnar; Sutton, Rosemary; Stary, Jan; Trka, Jan; Zuna, Jan

2017-05-18

We used the genomic breakpoint between BCR and ABL1 genes for the DNA-based monitoring of minimal residual disease (MRD) in 48 patients with childhood acute lymphoblastic leukemia (ALL). Comparing the results with standard MRD monitoring based on immunoglobulin/T-cell receptor (Ig/TCR) gene rearrangements and with quantification of IKZF1 deletion, we observed very good correlation for the methods in a majority of patients; however, >20% of children (25% [8/32] with minor and 12.5% [1/8] with major- BCR-ABL1 variants in the consecutive cohorts) had significantly (>1 log) higher levels of BCR-ABL1 fusion than Ig/TCR rearrangements and/or IKZF1 deletion. We performed cell sorting of the diagnostic material and assessed the frequency of BCR-ABL1 -positive cells in various hematopoietic subpopulations; 12% to 83% of non-ALL B lymphocytes, T cells, and/or myeloid cells harbored the BCR-ABL1 fusion in patients with discrepant MRD results. The multilineage involvement of the BCR-ABL1 -positive clone demonstrates that in some patients diagnosed with BCR-ABL1 -positive ALL, a multipotent hematopoietic progenitor is affected by the BCR-ABL1 fusion. These patients have BCR-ABL1 -positive clonal hematopoiesis resembling a chronic myeloid leukemia (CML)-like disease manifesting in "lymphoid blast crisis." The biological heterogeneity of BCR-ABL1 -positive ALL may impact the patient outcomes and optimal treatment (early stem cell transplantation vs long-term administration of tyrosine-kinase inhibitors) as well as on MRD testing. Therefore, we recommend further investigations on CML-like BCR-ABL1 -positive ALL. © 2017 by The American Society of Hematology.

Quality assurance in RT-PCR-based BCR/ABL diagnostics--results of an interlaboratory test and a standardization approach.

PubMed

Burmeister, T; Maurer, J; Aivado, M; Elmaagacli, A H; Grünebach, F; Held, K R; Hess, G; Hochhaus, A; Höppner, W; Lentes, K U; Lübbert, M; Schäfer, K L; Schafhausen, P; Schmidt, C A; Schüler, F; Seeger, K; Seelig, R; Thiede, C; Viehmann, S; Weber, C; Wilhelm, S; Christmann, A; Clement, J H; Ebener, U; Enczmann, J; Leo, R; Schleuning, M; Schoch, R; Thiel, E

2000-10-01

Here we describe the results of an interlaboratory test for RT-PCR-based BCR/ABL analysis. The test was organized in two parts. The number of participating laboratories in the first and second part was 27 and 20, respectively. In the first part samples containing various concentrations of plasmids with the ela2, b2a2 or b3a2 BCR/ABL transcripts were analyzed by PCR. In the second part of the test, cell samples containing various concentrations of BCR/ABL-positive cells were analyzed by RT-PCR. Overall PCR sensitivity was sufficient in approximately 90% of the tests, but a significant number of false positive results were obtained. There were significant differences in sensitivity in the cell-based analysis between the various participants. The results are discussed, and proposals are made regarding the choice of primers, controls, conditions for RNA extraction and reverse transcription.

Tyrosine kinase fusion genes in pediatric BCR-ABL1-like acute lymphoblastic leukemia

PubMed Central

Boer, Judith M.; Steeghs, Elisabeth M.P.; Marchante, João R.M.; Boeree, Aurélie; Beaudoin, James J.; Berna Beverloo, H.; Kuiper, Roland P.; Escherich, Gabriele; van der Velden, Vincent H.J.; van der Schoot, C. Ellen; de Groot-Kruseman, Hester A.; Pieters, Rob; den Boer, Monique L.

2017-01-01

Approximately 15% of pediatric B cell precursor acute lymphoblastic leukemia (BCP-ALL) is characterized by gene expression similar to that of BCR-ABL1-positive disease and unfavorable prognosis. This BCR-ABL1-like subtype shows a high frequency of B-cell development gene aberrations and tyrosine kinase-activating lesions. To evaluate the clinical significance of tyrosine kinase gene fusions in children with BCP-ALL, we studied the frequency of recently identified tyrosine kinase fusions, associated genetic features, and prognosis in a representative Dutch/German cohort. We identified 14 tyrosine kinase fusions among 77 BCR-ABL1-like cases (18%) and none among 76 non-BCR-ABL1-like B-other cases. Novel exon fusions were identified for RCSD1-ABL2 and TERF2-JAK2. JAK2 mutation was mutually exclusive with tyrosine kinase fusions and only occurred in cases with high CRLF2 expression. The non/late response rate and levels of minimal residual disease in the fusion-positive BCR-ABL1-like group were higher than in the non-BCR-ABL1-like B-others (p<0.01), and also higher, albeit not statistically significant, compared with the fusion-negative BCR-ABL1-like group. The 8-year cumulative incidence of relapse in the fusion-positive BCR-ABL1-like group (35%) was comparable with that in the fusion-negative BCR-ABL1-like group (35%), and worse than in the non-BCR-ABL1-like B-other group (17%, p=0.07). IKZF1 deletions, predominantly other than the dominant-negative isoform and full deletion, co-occurred with tyrosine kinase fusions. This study shows that tyrosine kinase fusion-positive cases are a high-risk subtype of BCP-ALL, which warrants further studies with specific kinase inhibitors to improve outcome. PMID:27894077

Association between Altered Expression and Genetic Variations of Transforming Growth Factor β-Smad Pathway with Chronic Myeloid Leukemia.

PubMed

Shokeen, Yogender; Sharma, Neeta Raj; Vats, Abhishek; Dinand, Veronique; Beg, Mirza Adil; Sanskaran, Satish; Minhas, Sachin; Jauhri, Mayank; Hariharan, Arun K; Taneja, Vibha; Aggarwal, Shyam

2018-01-01

Background: Chronic myeloid leukemia (CML) is a hematological disorder caused by fusion of BCR and ABL genes. BCR-ABL dependent and independent pathways play equally important role in CML. TGFβ-Smad pathway, an important BCR -ABL independent pathway, has scarce data in CML. Present study investigate the association between TGFβ-Smad pathway and CML. Materials and Methods: Sixty-four CML patients and age matched healthy controls (n=63) were enrolled in this study. Patients were segregated into responder and resistant groups depending on their response to Imatinib mesylate (IM). TGFβ1 serum levels were evaluated by ELISA and transcript levels of TGFβ1 receptors, SMAD4 and SMAD7 were evaluated by Real-Time PCR. Sequencing of exons and exon-intron boundaries of study genes was performed using Next Generation Sequencing (NGS) in 20 CML patients. Statistical analysis was performed using SPSS version 16.0. Results: TGFβ1 serum levels were significantly elevated ( p = 0.02) and TGFβR2 and SMAD4 were significantly down-regulated ( p = 0.012 and p = 0.043 respectively) in the patients. c.69A>G in TGFβ1 , c.1024+24G>A in TGFβR1 and g.46474746C>T in SMAD7 were the most important genetic variants observed with their presence in 10/20, 8/20 and 7/20 patients respectively. In addition, TGFβR1 transcript levels were reduced in CML patients with c.69A>G mutation. None of the genes differed significantly in terms of expression or genetic variants between responder and resistant patient groups. Conclusion: Our findings demonstrate the role of differential expression and genetic variants of TGFβ-Smad pathway in CML. Decreased TGFβR2 and SMAD4 levels observed in the present study may be responsible for reduced tumor suppressive effects of this pathway in CML.

A novel method for room temperature distribution and conservation of RNA and DNA reference materials for guaranteeing performance of molecular diagnostics in onco-hematology: A GBMHM study.

PubMed

Cayuela, Jean-Michel; Mauté, Carole; Fabre, Anne-Lise; Nibourel, Olivier; Dulucq, Stéphanie; Delabesse, Eric; Villarèse, Patrick; Hayette, Sandrine; Mozziconacci, Marie-Joelle; Macintyre, Elizabeth

2015-10-01

Performance of methods used for molecular diagnostics must be closely controlled by regular analysis of internal quality controls. However, conditioning, shipping and long lasting storage of nucleic acid controls remain problematic. Therefore, we evaluated the minicapsule-based innovative process developed by Imagene (Evry, France) for implementing DNA and RNA controls designed for clonality assessment of lymphoproliferations and BCR-ABL1 mRNA quantification, respectively. DNA samples were extracted from 12 cell lines selected for giving specific amplifications with most BIOMED-2 PCR tubes. RNA samples were extracted from 8 cell line mixtures expressing various BCR-ABL1 transcript levels. DNA and RNA were encapsulated by Imagene and shipped at room temperature to participating laboratories. Biologists were asked to report quality data of recovered nucleic acids as well as PCR results. Encapsulated nucleic acids samples were easily and efficiently recovered from minicapsules. The expected rearrangements at immunoglobulin, T-cell receptor and BCL2 loci were detected in DNA samples by all laboratories. Quality of RNA was consistent between laboratories and met the criteria requested for quantification of BCR-ABL1 transcripts. Expression levels measured by the 5 laboratories were within ±2 fold interval from the corresponding pre-encapsulation reference value. Moreover aging studies of encapsulated RNA simulating up to 100 years storage at room temperature show no bias in quantitative outcome. Therefore, Imagene minicapsules are suitable for storage and distribution at room temperature of genetic material designed for proficiency control of molecular diagnostic methods based on end point or real-time quantitative PCR. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Transposon-mediated generation of BCR-ABL1-expressing transgenic cell lines for unbiased sensitivity testing of tyrosine kinase inhibitors.

PubMed

Byrgazov, Konstantin; Lucini, Chantal Blanche; Berkowitsch, Bettina; Koenig, Margit; Haas, Oskar A; Hoermann, Gregor; Valent, Peter; Lion, Thomas

2016-11-22

Point mutations in the ABL1 kinase domain are an important mechanism of resistance to tyrosine kinase inhibitors (TKI) in BCR-ABL1-positive and, as recently shown, BCR-ABL1-like leukemias. The cell line Ba/F3 lentivirally transduced with mutant BCR-ABL1 constructs is widely used for in vitro sensitivity testing and response prediction to tyrosine kinase inhibitors. The transposon-based Sleeping Beauty system presented offers several advantages over lentiviral transduction including the absence of biosafety issues, faster generation of transgenic cell lines, and greater efficacy in introducing large gene constructs. Nevertheless, both methods can mediate multiple insertions in the genome. Here we show that multiple BCR-ABL1 insertions result in elevated IC50 levels for individual TKIs, thus overestimating the actual resistance of mutant subclones. We have therefore established flow-sorting-based fractionation of BCR-ABL1-transformed Ba/F3 cells facilitating efficient enrichment of cells carrying single-site insertions, as demonstrated by FISH-analysis. Fractions of unselected Ba/F3 cells not only showed a greater number of BCR-ABL1 hybridization signals, but also revealed higher IC50 values for the TKIs tested. The data presented highlight the need to carefully select transfected cells by flow-sorting, and to control the insertion numbers by FISH and real-time PCR to permit unbiased in vitro testing of drug resistance.

Molecular techniques for the personalised management of patients with chronic myeloid leukaemia.

PubMed

Alikian, Mary; Gale, Robert Peter; Apperley, Jane F; Foroni, Letizia

2017-03-01

Chronic myeloid leukemia (CML) is the paradigm for targeted cancer therapy. RT-qPCR is the gold standard for monitoring response to tyrosine kinase-inhibitor (TKI) therapy based on the reduction of blood or bone marrow BCR-ABL1 . Some patients with CML and very low or undetectable levels of BCR-ABL1 transcripts can stop TKI-therapy without CML recurrence. However, about 60 percent of patients discontinuing TKI-therapy have rapid leukaemia recurrence. This has increased the need for more sensitive and specific techniques to measure residual CML cells. The clinical challenge is to determine when it is safe to stop TKI-therapy. In this review we describe and critically evaluate the current state of CML clinical management, different technologies used to monitor measurable residual disease (MRD) focus on comparingRT-qPCR and new methods entering clinical practice. We discuss advantages and disadvantages of new methods.

Coexistence of inversion 16 and the Philadelphia chromosome comprising P190 BCR/ABL in chronic myeloid leukemia blast crisis.

PubMed

Ninomiya, Soranobu; Kanemura, Nobuhiro; Tsurumi, Hisashi; Kasahara, Senji; Hara, Takeshi; Yamada, Toshiki; Moriwaki, Hisataka

2011-06-01

A 63-year-old woman presented with leukocytosis (278 × 10(9)/L) with 72% blasts. Bone marrow blast cells showed cytogenetic abnormality with 46,XX, t(9;22), inv(16). Despite achievement of hematological remission by induction chemotherapy, Philadelphia chromosome did not disappear; chronic myeloid leukemia (CML) in blast crisis (BC) was thus diagnosed. The P190 BCR/ABL fusion transcript was detected. Imatinib mesylate introduced a hematological remission of short duration; however, infiltration into the central nervous system occurred, and the patient died 7 months after presentation. Coexistence of inv(16) and t(9:22) has been described in CML-BC and de novo AML, and CML-BC patients always carry P210 BCR/ABL, while de novo AML patients usually have P190 BCR/ABL. To the best of our knowledge, this is the first report of CML-BC with inv(16) and P190 BCR/ABL. We discuss this case with reference to the literature.

Genetic evaluation of childhood acute lymphoblastic leukemia in Iraq using FTA cards.

PubMed

Al-Kzayer, Lika'a Fasih Y; Sakashita, Kazuo; Matsuda, Kazuyuki; Al-Hadad, Salma Abbas; Al-Jadiry, Mazin Faisal; Abed, Wisam Majeed; Abdulkadhim, Jaafar M H; Al-Shujairi, Tariq Abadi; Hasan, Janan Ghalib; Al-Abdullah, Hussam M Salih; Al-Ani, Mouroge H; Saber, Paiman Ali I; Inoshita, Toshi; Kamata, Minoru; Koike, Kenichi

2012-09-01

Genetic examination of childhood leukemia has not been available in Iraq. We here report the frequency of TEL-AML1, E2A-PBX1, MLL-AF4, and BCR-ABL chimeric transcripts in 264 Iraqi children newly diagnosed with acute lymphoblastic leukemia (ALL), using FTA cards impregnated with bone marrow aspirate or whole blood. The diagnosis of ALL was made according to standard French-American-British morphologic criteria. Based on the results of storage temperature and duration, most of the FTA samples were preserved at 4°C for up to 6 weeks in five Iraqi hospitals and then transferred to Japan for molecular analysis. Nested reverse transcription-polymerase chain reaction was adopted for the analysis. TEL-AML1 chimeric transcript product was found in 32 (12.1%) of 264 ALL patients. Eleven (4.2%) patients, 4 (1.5%) patients, and 11 (4.2%) patients had E2A-PBX1 mRNA, MLL-AF4 mRNA, and BCR-ABL mRNA, respectively. One patient had both TEL-AML1 and E2A-PBX1 fusion genes. The incidence of TEL-AML1 in Iraqi ALL children appears to be similar to or slightly higher than those of Jordan (12%) and Kuwait (7%). The prevalence and clinical findings of ALL patients with either E2A-PBX1 or BCR-ABL were comparable to the data reported elsewhere. International collaboration via FTA cards may be helpful to improve diagnosis and management of patients with hematological malignancies in low-income and underdeveloped countries. Copyright © 2012 Wiley Periodicals, Inc.

Deregulated expression of Cdc6 as BCR/ABL-dependent survival factor in chronic myeloid leukemia cells.

PubMed

Zhang, Jia-Hua; He, Yan-Li; Zhu, Rui; Du, Wen; Xiao, Jun-Hua

2017-06-01

Chronic myeloid leukemia is characterized by the presence of the reciprocal translocation t(9;22) and the BCR/ABL oncogene. The BCR/ABL oncogene activates multiple signaling pathways and involves the dysregulation of oncogenes during the progression of chronic myeloid leukemia. The cell division cycle protein 6, an essential regulator of DNA replication, is elevated in some human cancer cells. However, the expression of cell division cycle protein 6 in chronic myeloid leukemia and the underlying regulatory mechanism remain to be elucidated. In this study, our data showed that cell division cycle protein 6 expression was significantly upregulated in primary chronic myeloid leukemia cells and the chronic myeloid leukemia cell line K562 cells, as compared to the normal bone marrow mononuclear cells. BCR/ABL kinase inhibitor STI571 or BCR/ABL small interfering RNA could significantly downregulate cell division cycle protein 6 messenger RNA expression in K562 cells. Moreover, phosphoinositide 3-kinase/AKT pathway inhibitor LY294002 and Janus kinase/signal transducer and activator of transcription pathway inhibitor AG490 could downregulate cell division cycle protein 6 expression in K562 cells, but not RAS/mitogen-activated protein kinase pathway inhibitor PD98059 had such effect. Cell division cycle protein 6 gene silencing by small interfering RNA effectively resulted in decrease of proliferation, increase of apoptosis, and arrest of cell cycle in K562 cells. These findings have demonstrated that cell division cycle protein 6 overexpression may contribute to the high proliferation and low apoptosis in chronic myeloid leukemia cells and can be regulated by BCR/ABL signal transduction through downstream phosphoinositide 3-kinase/Akt and Janus kinase/signal transducer and activator of transcription pathways, suggesting cell division cycle protein 6 as a potential therapeutic target in chronic myeloid leukemia.

Transposon-mediated generation of BCR-ABL1-expressing transgenic cell lines for unbiased sensitivity testing of tyrosine kinase inhibitors

PubMed Central

Berkowitsch, Bettina; Koenig, Margit; Haas, Oskar A.; Hoermann, Gregor; Valent, Peter; Lion, Thomas

2016-01-01

Point mutations in the ABL1 kinase domain are an important mechanism of resistance to tyrosine kinase inhibitors (TKI) in BCR-ABL1-positive and, as recently shown, BCR-ABL1-like leukemias. The cell line Ba/F3 lentivirally transduced with mutant BCR-ABL1 constructs is widely used for in vitro sensitivity testing and response prediction to tyrosine kinase inhibitors. The transposon-based Sleeping Beauty system presented offers several advantages over lentiviral transduction including the absence of biosafety issues, faster generation of transgenic cell lines, and greater efficacy in introducing large gene constructs. Nevertheless, both methods can mediate multiple insertions in the genome. Here we show that multiple BCR-ABL1 insertions result in elevated IC50 levels for individual TKIs, thus overestimating the actual resistance of mutant subclones. We have therefore established flow-sorting-based fractionation of BCR-ABL1-transformed Ba/F3 cells facilitating efficient enrichment of cells carrying single-site insertions, as demonstrated by FISH-analysis. Fractions of unselected Ba/F3 cells not only showed a greater number of BCR-ABL1 hybridization signals, but also revealed higher IC50 values for the TKIs tested. The data presented highlight the need to carefully select transfected cells by flow-sorting, and to control the insertion numbers by FISH and real-time PCR to permit unbiased in vitro testing of drug resistance. PMID:27801667

A role for FOXO1 in BCR-ABL1-independent tyrosine kinase inhibitor resistance in chronic myeloid leukemia.

PubMed

Wagle, M; Eiring, A M; Wongchenko, M; Lu, S; Guan, Y; Wang, Y; Lackner, M; Amler, L; Hampton, G; Deininger, M W; O'Hare, T; Yan, Y

2016-07-01

Chronic myeloid leukemia (CML) patients who relapse on imatinib due to acquired ABL1 kinase domain mutations are successfully treated with second-generation ABL1-tyrosine kinase inhibitors (ABL-TKIs) such as dasatinib, nilotinib or ponatinib. However, ~40% of relapsed patients have uncharacterized BCR-ABL1 kinase-independent mechanisms of resistance. To identify these mechanisms of resistance and potential treatment options, we generated ABL-TKI-resistant K562 cells through prolonged sequential exposure to imatinib and dasatinib. Dual-resistant K562 cells lacked BCR-ABL1 kinase domain mutations, but acquired other genomic aberrations that were characterized by next-generation sequencing and copy number analyses. Proteomics showed that dual-resistant cells had elevated levels of FOXO1, phospho-ERK and BCL-2, and that dasatinib no longer inhibited substrates of the PI3K/AKT pathway. In contrast to parental cells, resistant cells were sensitive to growth inhibition and apoptosis induced by the class I PI3K inhibitor, GDC-0941 (pictilisib), which also induced FOXO1 nuclear translocation. FOXO1 was elevated in a subset of primary specimens from relapsed CML patients lacking BCR-ABL1 kinase domain mutations, and these samples were responsive to GDC-0941 treatment ex vivo. We conclude that elevated FOXO1 contributes to BCR-ABL1 kinase-independent resistance experienced by these CML patients and that PI3K inhibition coupled with BCR-ABL1 inhibition may represent a novel therapeutic approach.

The effect of Bcr-Abl protein tyrosine kinase on maturation and proliferation of primitive haematopoietic cells.

PubMed Central

Buckle, A. M.; Mottram, R.; Pierce, A.; Lucas, G. S.; Russell, N.; Miyan, J. A.; Whetton, A. D.

2000-01-01

BACKGROUND: Chronic Myeloid Leukaemia (CML) is characterised by the chromosomal translocation resulting in expression of the Bcr-Abl protein tyrosine kinase (PTK) in early stem cells and their progeny. However the precise nature of Bcr-Abl effects in primitive CML stem cells remains a matter of active debate. MATERIALS AND METHODS: Extremely primitive Bcr-Abl fusion positive cells were purified from patients with CML using multiparameter flow cytometric analysis of CD34, Thy, and lineage marker (Lin) expression, plus rhodamine-123 (Rh-123) brightness. Progenitor cells of increasing maturity were examined for cycling status by flow cytometry and their proliferative status directly correlated with cell phenotype. The activation status of a key transcription factor, signal transducers and activators of transcription (STAT-5), was also analyzed by immunocytochemistry. RESULTS: The most primitive stem cells currently defined (CD34+Lin-Thy+ Rh-1231o) were present as a lower proportion of the stem cell compartment (CD34+Lin-) of CML patients at presentation than of normal individuals (2.3% +/- 0.4 compared with 5.1% +/- 0.6 respectively). Conversely there was a significantly higher proportion of the more mature cells (CD34+Lin-Thy-Rh-123 hi) in CML patients than in normal individuals (79.3 +/- 1.8 compared with 70.9 +/- 3.3). No primitive subpopulation of CML CD34+Lin- cells was cycling to a significantly greater degree than cells from normal donors, in fact, late progenitor cells (CD34+Lin+) were cycling significantly less in CML samples than normal samples. STAT5, however, was observed to be activated in CML cells. CONCLUSIONS: We conclude that no subpopulation of CML stem cells displays significantly increased cell cycling. Thus, increased cycling cannot be a direct consequence of Bcr-Abl PTK acquisition in highly enriched stem cells from patients with CML. In vivo CML need not be considered a disease of unbridled stem cell proliferation, but a subtle defect in the balance between self renewal and maturation. PMID:11126203

Electrochemical branched-DNA assay for polymerase chain reaction-free detection and quantification of oncogenes in messenger RNA.

PubMed

Lee, Ai-Cheng; Dai, Ziyu; Chen, Baowei; Wu, Hong; Wang, Jun; Zhang, Aiguo; Zhang, Lurong; Lim, Tit-Meng; Lin, Yuehe

2008-12-15

We describe a novel electrochemical branched-DNA (bDNA) assay for polymerase chain reaction (PCR)-free detection and quantification of p185 BCR-ABL leukemia fusion transcripts in the population of messenger ribonucleic acid (mRNA) extracted from cell lines. The bDNA amplifier carrying high loading of alkaline phosphatase (ALP) tracers was used to amplify the target signal. The targets were captured on microplate well surfaces through cooperative sandwich hybridization prior to the labeling of bDNA. The activity of captured ALP was monitored by square-wave voltammetric (SWV) analysis of the electroactive enzymatic product in the presence of 1-naphthyl phosphate. The voltammetric characteristics of substrate and enzymatic product as well as the parameters of SWV analysis were systematically optimized. A detection limit of 1 fM (1 x 10(-19) mol of target transcripts in 100 microL) and a 3-order-wide dynamic range of target concentration were achieved by the electrochemical bDNA assay. Such limit corresponded to approximately 17 fg of the p185 BCR-ABL fusion transcripts. The specificity and sensitivity of assay enabled direct detection of target transcripts in as little as 4.6 ng of mRNA population without PCR amplification. In combination with the use of a well-quantified standard, the electrochemical bDNA assay was capable of direct use for a PCR-free quantitative analysis of target transcripts in mRNA population. A mean transcript copy number of 62,900/ng of mRNA was determined, which was at least 50-fold higher than that of real-time quantitative PCR (qPCR). The finding was consistent with the underestimation of targets by qPCR reported earlier. In addition, the unique design based on bDNA technology increases the assay specificity as only the p185 BCR-ABL fusion transcripts will respond to the detection. The approach thus provides a simple, sensitive, accurate, and quantitative tool alternative to the qPCR for early disease diagnosis.

Co-expression of HoxA9 and bcr-abl genes in chronic myeloid leukemia.

PubMed

Tedeschi, Fabián A; Cardozo, Maria A; Valentini, Rosanna; Zalazar, Fabián E

2010-05-01

We have analyzed the co-expression of the bcr-abl and HoxA9 genes in the follow-up of patients with chronic myeloid leukemia (CML). In the present work we measured the HoxA9 and bcr-abl gene expression in sequential samples. In all patients, bcr-abl and HoxA9 were expressed at detectable levels in every sample. When the results were expressed in relation to abl, two different situations were found: (a) patients clinically stable at second sampling, with low relative risk at diagnosis (low Sokal's score), did not show significant differences in both bcr-abl and HoxA9 levels in the sequential samples analyzed, and (b) patients with poor prognosis (showing intermediate or high Sokal's score at diagnosis) had increased expression of bcr-abl as well as HoxA9 genes (p < 0.05). Since HoxA9 gene expression remains at relatively constant levels throughout adult life, our results could reflect actual changes in the expression rate of this gene associated with bcr-abl during the progression of CML.

Bcr-Abl and inhibition of apoptosis in chronic myelogenous leukemia cells.

PubMed

Fernandez-Luna, J L

2000-10-01

Chronic myelogenous leukemia (CML) cells are highly resistant to apoptosis induced by chemotherapeutic drugs. The observation that production of Bcr-Abl is the initiating event in CML has focussed attention on the survival signals triggered by this oncogene. A number of signal transducers and transcription factors have been associated with the antiapoptotic phenotype of CML cells, some of which lead to the expression and/or activation of members of the Bcl-2 family of apoptosis modulators, such as Bcl-xL and Bad. In this article, recent advances in understanding the antiapoptotic pathways triggered by Bcr-Abl in CML cells, are discussed.

Imatinib mesylate (STI571) decreases the vascular endothelial growth factor plasma concentration in patients with chronic myeloid leukemia.

PubMed

Legros, Laurence; Bourcier, Christine; Jacquel, Arnaud; Mahon, François-Xavier; Cassuto, Jill-Patrice; Auberger, Patrick; Pagès, Gilles

2004-07-15

Increased angiogenesis in bone marrow (BM) is one of the characteristics of chronic myeloid leukemia (CML), a clonal myeloproliferative disorder that expresses a chimeric Bcr/Abl protein. Recently, the therapeutic strategy in CML has been totally modified with the development of a new drug: imatinib mesylate (STI571), a specific inhibitor of Bcr/Abl tyrosine kinase activity. The aim of our study was to determine, in patients with CML, the capacity of imatinib mesylate to modulate one of the most potent regulators of angiogenesis, the vascular endothelial growth factor (VEGF). In newly diagnosed CML, we observed significantly increased VEGF secretion by CML BM cells and significantly increased VEGF plasma concentrations. We showed that low plasma VEGF concentrations could be one of the characteristics of complete cytogenetic remission. To understand the molecular mechanisms leading to the inhibition of VEGF production by imatinib, we focused our experiments on the human cell line K562, which is Bcr/Abl positive. We demonstrated that imatinib inhibits VEGF gene transcription by targeting the Sp1 and Sp3 transcription factors. Taken together, our results highlight the potential prognostic value of VEGF concentrations in evaluating the evolution of CML patients treated with imatinib.

Fast-mode duplex qPCR for BCR-ABL1 molecular monitoring: innovation, automation, and harmonization.

PubMed

Gerrard, Gareth; Mudge, Katherine; Foskett, Pierre; Stevens, David; Alikian, Mary; White, Helen E; Cross, Nicholas C P; Apperley, Jane; Foroni, Letizia

2012-07-01

Reverse transcription quantitative polymerase chain reaction (RTqPCR)is currently the most sensitive tool available for the routine monitoring of disease level in patients undergoing treatment for BCRABL1 associated malignancies. Considerable effort has been invested at both the local and international levels to standardise the methodology and reporting criteria used to assess this critical metric. In an effort to accommodate the demands of increasing sample throughput and greater standardization, we adapted the current best-practice guidelines to encompass automation platforms and improved multiplex RT-qPCR technology.

PP2A-activating drugs selectively eradicate TKI-resistant chronic myeloid leukemic stem cells

PubMed Central

Neviani, Paolo; Harb, Jason G.; Oaks, Joshua J.; Santhanam, Ramasamy; Walker, Christopher J.; Ellis, Justin J.; Ferenchak, Gregory; Dorrance, Adrienne M.; Paisie, Carolyn A.; Eiring, Anna M.; Ma, Yihui; Mao, Hsiaoyin C.; Zhang, Bin; Wunderlich, Mark; May, Philippa C.; Sun, Chaode; Saddoughi, Sahar A.; Bielawski, Jacek; Blum, William; Klisovic, Rebecca B.; Solt, Janelle A.; Byrd, John C.; Volinia, Stefano; Cortes, Jorge; Huettner, Claudia S.; Koschmieder, Steffen; Holyoake, Tessa L.; Devine, Steven; Caligiuri, Michael A.; Croce, Carlo M.; Garzon, Ramiro; Ogretmen, Besim; Arlinghaus, Ralph B.; Chen, Ching-Shih; Bittman, Robert; Hokland, Peter; Roy, Denis-Claude; Milojkovic, Dragana; Apperley, Jane; Goldman, John M.; Reid, Alistair; Mulloy, James C.; Bhatia, Ravi; Marcucci, Guido; Perrotti, Danilo

2013-01-01

The success of tyrosine kinase inhibitors (TKIs) in treating chronic myeloid leukemia (CML) depends on the requirement for BCR-ABL1 kinase activity in CML progenitors. However, CML quiescent HSCs are TKI resistant and represent a BCR-ABL1 kinase–independent disease reservoir. Here we have shown that persistence of leukemic HSCs in BM requires inhibition of the tumor suppressor protein phosphatase 2A (PP2A) and expression — but not activity — of the BCR-ABL1 oncogene. Examination of HSCs from CML patients and healthy individuals revealed that PP2A activity was suppressed in CML compared with normal HSCs. TKI-resistant CML quiescent HSCs showed increased levels of BCR-ABL1, but very low kinase activity. BCR-ABL1 expression, but not kinase function, was required for recruitment of JAK2, activation of a JAK2/β-catenin survival/self-renewal pathway, and inhibition of PP2A. PP2A-activating drugs (PADs) markedly reduced survival and self-renewal of CML quiescent HSCs, but not normal quiescent HSCs, through BCR-ABL1 kinase–independent and PP2A-mediated inhibition of JAK2 and β-catenin. This led to suppression of human leukemic, but not normal, HSC/progenitor survival in BM xenografts and interference with long-term maintenance of BCR-ABL1–positive HSCs in serial transplantation assays. Targeting the JAK2/PP2A/β-catenin network in quiescent HSCs with PADs (e.g., FTY720) has the potential to treat TKI-refractory CML and relieve lifelong patient dependence on TKIs. PMID:23999433

Molecular dynamics reveal BCR-ABL1 polymutants as a unique mechanism of resistance to PAN-BCR-ABL1 kinase inhibitor therapy

PubMed Central

Gibbons, Don L.; Pricl, Sabrina; Posocco, Paola; Laurini, Erik; Fermeglia, Maurizio; Sun, Hanshi; Talpaz, Moshe; Donato, Nicholas; Quintás-Cardama, Alfonso

2014-01-01

The acquisition of mutations within the BCR-ABL1 kinase domain is frequently associated with tyrosine kinase inhibitor (TKI) failure in chronic myeloid leukemia. Sensitive sequencing techniques have revealed a high prevalence of compound BCR-ABL1 mutations (polymutants) in patients failing TKI therapy. To investigate the molecular consequences of such complex mutant proteins with regards to TKI resistance, we determined by cloning techniques the presence of polymutants in a cohort of chronic-phase patients receiving imatinib followed by dasatinib therapy. The analysis revealed a high frequency of polymutant BCR-ABL1 alleles even after failure of frontline imatinib, and also the progressive exhaustion of the pool of unmutated BCR-ABL1 alleles over the course of sequential TKI therapy. Molecular dynamics analyses of the most frequent polymutants in complex with TKIs revealed the basis of TKI resistance. Modeling of BCR-ABL1 in complex with the potent pan-BCR-ABL1 TKI ponatinib highlighted potentially effective therapeutic strategies for patients carrying these recalcitrant and complex BCR-ABL1 mutant proteins while unveiling unique mechanisms of escape to ponatinib therapy. PMID:24550512

Ethnic differences in the frequency of subtypes of childhood acute lymphoblastic leukemia: results of the Malaysia-Singapore Leukemia Study Group.

PubMed

Ariffin, Hany; Chen, Siew-Peng; Kwok, Cecilia S; Quah, Thuan-Chong; Lin, Hai-Peng; Yeoh, Allen E J

2007-01-01

Childhood acute lymphoblastic leukemia (ALL) is clinically heterogeneous with prognostically and biologically distinct subtypes. Although racial differences in frequency of different types of childhood ALL have been reported, many are confounded by selected or limited population samples. The Malaysia-Singapore (MA-SPORE) Leukemia Study Group provided a unique platform for the study of the frequency of major subgroups of childhood ALL in a large cohort of unselected multiethnic Asian children. Screening for the prognostically important chromosome abnormalities (TEL-AML1, BCR-ABL, E2A-PBX1, and MLL) using multiplex reverse-transcription polymerase chain reaction was performed on 299 consecutive patients with ALL at 3 study centers (236 de novo, 63 at relapse), with the ethnic composition predominantly Chinese (51.8%) and Malay (34.8%). Reverse-transcription polymerase chain reaction was successful in 278 (93%) of cases screened. The commonest fusion transcript was TEL-AML1 (19.1%) followed by BCR-ABL (7.8%), MLL rearrangements (4.2%), and E2A-PBX1 (3.1%). Chinese have a significantly lower frequency of TEL-AML1 (13.3% in de novo patients) compared with Malays (22.2%) and Indians (21.7%) (P=0.04). Malays have a lower frequency of T-ALL (6.2%) compared with the Chinese and Indians (9.8%). Both Malays (7.4%) and Chinese (5.0%) have significantly higher frequency of BCR-ABL compared with the Indian population (P<0.05) despite a similar median age at presentation. Our study suggests that there are indeed significant and important racial differences in the frequency of subtypes of childhood ALL. Comprehensive subgrouping of childhood ALL may reveal interesting population frequency differences of the various subtypes, their risk factors and hopefully, its etiology.

Bcr-Abl induces abnormal cytoskeleton remodeling, beta1 integrin clustering and increased cell adhesion to fibronectin through the Abl interactor 1 pathway.

PubMed

Li, Yingzhu; Clough, Nancy; Sun, Xiaolin; Yu, Weidong; Abbott, Brian L; Hogan, Christopher J; Dai, Zonghan

2007-04-15

Hematopoietic cells isolated from patients with Bcr-Abl-positive leukemia exhibit multiple abnormalities of cytoskeletal and integrin function. These abnormalities are thought to play a role in the pathogenesis of leukemia; however, the molecular events leading to these abnormalities are not fully understood. We show here that the Abi1 pathway is required for Bcr-Abl to stimulate actin cytoskeleton remodeling, integrin clustering and cell adhesion. Expression of Bcr-Abl induces tyrosine phosphorylation of Abi1. This is accompanied by a subcellular translocation of Abi1/WAVE2 to a site adjacent to membrane, where an F-actin-enriched structure containing the adhesion molecules such as beta1-integrin, paxillin and vinculin is assembled. Bcr-Abl-induced membrane translocation of Abi1/WAVE2 requires direct interaction between Abi1 and Bcr-Abl, but is independent of the phosphoinositide 3-kinase pathway. Formation of the F-actin-rich complex correlates with an increased cell adhesion to fibronectin. More importantly, disruption of the interaction between Bcr-Abl and Abi1 by mutations either in Bcr-Abl or Abi1 not only abolished tyrosine phosphorylation of Abi1 and membrane translocation of Abi1/WAVE2, but also inhibited Bcr-Abl-stimulated actin cytoskeleton remodeling, integrin clustering and cell adhesion to fibronectin. Together, these data define Abi1/WAVE2 as a downstream pathway that contributes to Bcr-Abl-induced abnormalities of cytoskeletal and integrin function.

Predictive value of minimal residual disease in Philadelphia-chromosome-positive acute lymphoblastic leukemia treated with imatinib in the European intergroup study of post-induction treatment of Philadelphia-chromosome-positive acute lymphoblastic leukemia, based on immunoglobulin/T-cell receptor and BCR/ABL1 methodologies

PubMed Central

Cazzaniga, Giovanni; De Lorenzo, Paola; Alten, Julia; Röttgers, Silja; Hancock, Jeremy; Saha, Vaskar; Castor, Anders; Madsen, Hans O.; Gandemer, Virginie; Cavé, Hélène; Leoni, Veronica; Köhler, Rolf; Ferrari, Giulia M.; Bleckmann, Kirsten; Pieters, Rob; van der Velden, Vincent; Stary, Jan; Zuna, Jan; Escherich, Gabriele; zur Stadt, Udo; Aricò, Maurizio; Conter, Valentino; Schrappe, Martin; Valsecchi, Maria Grazia; Biondi, Andrea

2018-01-01

The prognostic value of minimal residual disease (MRD) in Philadelphia-chromosome-positive (Ph+) childhood acute lymphoblastic leukemia (ALL) treated with tyrosine kinase inhibitors is not fully established. We detected MRD by real-time quantitative polymerase chain reaction (RQ-PCR) of rearranged immunoglobulin/T-cell receptor genes (IG/TR) and/or BCR/ABL1 fusion transcript to investigate its predictive value in patients receiving Berlin-Frankfurt-Münster (BFM) high-risk (HR) therapy and post-induction intermittent imatinib (the European intergroup study of post-induction treatment of Philadelphia-chromosome-positive acute lymphoblastic leukemia (EsPhALL) study). MRD was monitored after induction (time point (TP)1), consolidation Phase IB (TP2), HR Blocks, reinductions, and at the end of therapy. MRD negativity progressively increased over time, both by IG/TR and BCR/ABL1. Of 90 patients with IG/TR MRD at TP1, nine were negative and none relapsed, while 11 with MRD<5×10−4 and 70 with MRD≥5×10−4 had a comparable 5-year cumulative incidence of relapse of 36.4 (15.4) and 35.2 (5.9), respectively. Patients who achieved MRD negativity at TP2 had a low relapse risk (5-yr cumulative incidence of relapse (CIR)=14.3[9.8]), whereas those who attained MRD negativity at a later date showed higher CIR, comparable to patients with positive MRD at any level. BCR/ABL1 MRD negative patients at TP1 had a relapse risk similar to those who were IG/TR MRD negative (1/8 relapses). The overall concordance between the two methods is 69%, with significantly higher positivity by BCR/ABL1. In conclusion, MRD monitoring by both methods may be functional not only for measuring response but also for guiding biological studies aimed at investigating causes for discrepancies, although from our data IG/TR MRD monitoring appears to be more reliable. Early MRD negativity is highly predictive of favorable outcome. The earlier MRD negativity is achieved, the better the prognosis. PMID:29079599

Expression of BCR-ABL1 oncogene relative to ABL1 gene changes overtime in chronic myeloid leukemia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, Manu; Milani, Lili; Hermansson, Monica

Using a quantitative single nucleotide polymorphism (SNP) assay we have investigated the changes in the expression of the BCR-ABL1 oncogene relative to the wild-type ABL1 and BCR alleles in cells from chronic myeloid leukemia (CML) patients not responding to therapy. The results show a progressive increase in the BCR-ABL1 oncogene expression at the expense of decreased expression of the ABL1 allele, not involved in the fusion. No relative changes in the expression of the two BCR alleles were found. These results demonstrate that allele-specific changes in gene expression, with selective, progressive silencing of the wild-type ABL1 allele in favor ofmore » the oncogenic BCR-ABL1 allele occur in CML patients with therapy-resistant disease.« less

Targeted Blockage of Signal Transducer and Activator of Transcription 5 Signaling Pathway with Decoy Oligodeoxynucleotides Suppresses Leukemic K562 Cell Growth

PubMed Central

Wang, Xiaozhong; Zeng, Jianming; Shi, Mei; Zhao, Shiqiao; Bai, Weijun; Cao, Weixi; Tu, Zhiguang; Huang, Zonggan

2011-01-01

The protein signal transducer and activator of transcription 5 (STAT5) of the JAK/STAT pathway is constitutively activated because of its phosphorylation by tyrosine kinase activity of fusion protein BCR-ABL in chronic myelogenous leukemia (CML) cells. This study investigated the potential therapeutic effect of STAT5 decoy oligodeoxynucleotides (ODN) using leukemia K562 cells as a model. Our results showed that transfection of 21-mer-long STAT5 decoy ODN into K562 cells effectively inhibited cell proliferation and induced cell apoptosis. Further, STAT5 decoy ODN downregulated STAT5 targets bcl-xL, cyclinD1, and c-myc at both mRNA and protein levels in a sequence-specific manner. Collectively, these data demonstrate the therapeutic effect of blocking the STAT5 signal pathway by cis-element decoy for cancer characterized by constitutive STAT5 activation. Thus, our study provides support for STAT5 as a potential target downstream of BCR-ABL for CML treatment and helps establish the concept of targeting STAT5 by decoy ODN as a novel therapy approach for imatinib-resistant CML. PMID:21091189

Prevalence of Abelson murine leukemia viral oncogene homolog-breakpoint cluster region fusions and correlation with peripheral blood parameters in chronic myelogenous leukemia patients in Lorestan Province, Iran.

PubMed

Kiani, Ali Asghar; Shahsavar, Farhad; Gorji, Mojtaba; Ahmadi, Kolsoum; Nazarabad, Vahideh Heydari; Bahmani, Banafsheh

2016-01-01

Chronic myelogenous leukemia (CML) is a chronic malignancy of myeloid linage associated with a significant increase in granulocytes in bone marrow and peripheral blood. CML diagnosis is based on detection of Philadelphia chromosome and "Abelson murine leukemia viral oncogene homolog" (ABL)-"breakpoint cluster region protein" fusions (ABL-BCR fusions). In this study, patients with CML morphology were studied according to ABL-BCR fusions and the relationship between the fusions and peripheral blood cell changes was examined. All patients suspected to chronic myeloproliferative disorders in Lorestan Province visiting subspecialist hematology clinics who were confirmed by oncologist were studied over a period of 5 years. After completing basic data questionnaire, blood samples were obtained with informed consent from the patients. Blood cell count and morphology were investigated and RNA was extracted from blood samples. cDNA was synthesized from RNA and ABL-BCR fusions including b3a2 and b2a2 (protein 210 kd or p210), e1a2 (protein 190 kdor p190), and e19a2 (protein 230 kdor p230) were studied by multiplex reverse transcription polymerase chain reaction method. Coexistence of e1a2 and b2a2 (p210/p190) fusions was also studied. The prevalence of mutations and their correlation with the blood parameters were statistically analyzed. Of 58 patients positive for ABL-BCR fusion, 18 (30.5%) had b2a2 fusion, 37 (62.71%) had b3a2 fusion and three (3.08%) had e1a2 fusion. Coexistence of e1a2 and b2a2 (p210/p190) was not observed. There was no significant correlation between ABL-BCR fusions and white blood cell count, platelet count, and hemoglobin concentration. The ABL-BCR fusions in Lorestan Province were similar to other studies in Iran, and b3a2 fusion had the highest prevalence in the studied patients studied.

Sirolimus and Mycophenolate Mofetil in Preventing GVHD in Patients With Hematologic Malignancies Undergoing HSCT

ClinicalTrials.gov

2018-04-04

Adult Hodgkin Lymphoma; Adult Myelodysplastic Syndrome; Blast Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Childhood Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Childhood Hodgkin Lymphoma; Childhood Myelodysplastic Syndrome; Chronic Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Myelofibrosis; Primary Myelofibrosis; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Adult Non-Hodgkin Lymphoma; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Recurrent Childhood Non-Hodgkin Lymphoma; Recurrent Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Refractory Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Refractory Non-Hodgkin Lymphoma

GABP transcription factor is required for development of chronic myelogenous leukemia via its control of PRKD2.

PubMed

Yang, Zhong-Fa; Zhang, Haojian; Ma, Leyuan; Peng, Cong; Chen, Yaoyu; Wang, Junling; Green, Michael R; Li, Shaoguang; Rosmarin, Alan G

2013-02-05

Hematopoietic stem cells (HSCs) are the source of all blood lineages, and HSCs must balance quiescence, self-renewal, and differentiation to meet lifelong needs for blood cell development. Transformation of HSCs by the breakpoint cluster region-ABL tyrosine kinase (BCR-ABL) oncogene causes chronic myelogenous leukemia (CML). The E-twenty six (ets) transcription factor GA binding protein (GABP) is a tetrameric transcription factor complex that contains GABPα and GABPβ proteins. Deletion in bone marrow of Gabpa, the gene that encodes the DNA-binding component, caused cell cycle arrest in HSCs and profound loss of hematopoietic progenitor cells. Loss of Gabpα prevented development of CML, although mice continued to generate BCR-ABL-expressing Gabpα-null cells for months that were serially transplantable and contributed to all lineages in secondary recipients. A bioinformatic screen identified the serine-threonine kinase protein kinase D2 (PRKD2) as a potential effector of GABP in HSCs. Prkd2 expression was markedly reduced in Gabpα-null HSCs and progenitor cells. Reduced expression of PRKD2 or pharmacologic inhibition decreased cell cycling, and PRKD2 rescued growth of Gabpα-null BCR-ABL-expressing cells. Thus, GABP is required for HSC cell cycle entry and CML development through its control of PRKD2. This offers a potential therapeutic target in leukemia.

BCR-ABL enhances differentiation of long-term repopulating hematopoietic stem cells

PubMed Central

Schemionek, Mirle; Elling, Christian; Steidl, Ulrich; Bäumer, Nicole; Hamilton, Ashley; Spieker, Tilmann; Göthert, Joachim R.; Stehling, Martin; Wagers, Amy; Huettner, Claudia S.; Tenen, Daniel G.; Tickenbrock, Lara; Berdel, Wolfgang E.; Serve, Hubert; Holyoake, Tessa L.; Müller-Tidow, Carsten

2010-01-01

In a previously developed inducible transgenic mouse model of chronic myeloid leukemia, we now demonstrate that the disease is transplantable using BCR-ABL+ Lin−Sca-1+c-kit+ (LSK) cells. Interestingly, the phenotype is more severe when unfractionated bone marrow cells are transplanted, yet neither progenitor cells (Lin−Sca-1−c-kit+), nor mature granulocytes (CD11b+Gr-1+), nor potential stem cell niche cells (CD45−Ter119−) are able to transmit the disease or alter the phenotype. The phenotype is largely independent of BCR-ABL priming before transplantation. However, prolonged BCR-ABL expression abrogates the potential of LSK cells to induce full-blown disease in secondary recipients and increases the fraction of multipotent progenitor cells at the expense of long-term hematopoietic stem cells (LT-HSCs) in the bone marrow. BCR-ABL alters the expression of genes involved in proliferation, survival, and hematopoietic development, probably contributing to the reduced LT-HSC frequency within BCR-ABL+ LSK cells. Reversion of BCR-ABL, or treatment with imatinib, eradicates mature cells, whereas leukemic stem cells persist, giving rise to relapsed chronic myeloid leukemia on reinduction of BCR-ABL, or imatinib withdrawal. Our results suggest that BCR-ABL induces differentiation of LT-HSCs and decreases their self-renewal capacity. PMID:20053753

Compound mutations in BCR-ABL1 are not major drivers of primary or secondary resistance to ponatinib in CP-CML patients

PubMed Central

Hodgson, J. Graeme; Shah, Neil P.; Cortes, Jorge E.; Kim, Dong-Wook; Nicolini, Franck E.; Talpaz, Moshe; Baccarani, Michele; Müller, Martin C.; Li, Jin; Parker, Wendy T.; Lustgarten, Stephanie; Clackson, Tim; Haluska, Frank G.; Guilhot, Francois; Kantarjian, Hagop M.; Soverini, Simona; Hochhaus, Andreas; Hughes, Timothy P.; Rivera, Victor M.; Branford, Susan

2016-01-01

BCR-ABL1 kinase domain mutations can confer resistance to first- and second-generation tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML). In preclinical studies, clinically achievable concentrations of the third-generation BCR-ABL1 TKI ponatinib inhibit T315I and all other single BCR-ABL1 mutants except T315M, which generates a single amino acid exchange, but requires 2 sequential nucleotide exchanges. In addition, certain compound mutants (containing ≥2 mutations in cis) confer resistance. Initial analyses based largely on conventional Sanger sequencing (SS) have suggested that the preclinical relationship between BCR-ABL1 mutation status and ponatinib efficacy is generally recapitulated in patients receiving therapy. Thus far, however, such analyses have been limited by the inability of SS to definitively identify compound mutations or mutations representing less than ∼20% of total alleles (referred to as “low-level mutations”), as well as limited patient follow-up. Here we used next-generation sequencing (NGS) to define the baseline BCR-ABL1 mutation status of 267 heavily pretreated chronic phase (CP)-CML patients from the PACE trial, and used SS to identify clonally dominant mutants that may have developed on ponatinib therapy (30.1 months median follow-up). Durable cytogenetic and molecular responses were observed irrespective of baseline mutation status and included patients with compound mutations. No single or compound mutation was identified that consistently conferred primary and/or secondary resistance to ponatinib in CP-CML patients. Ponatinib is effective in CP-CML irrespective of baseline mutation status. PMID:26603839

Blockade of Y177 and Nuclear Translocation of Bcr-Abl Inhibits Proliferation and Promotes Apoptosis in Chronic Myeloid Leukemia Cells.

PubMed

Li, Qianyin; Huang, Zhenglan; Gao, Miao; Cao, Weixi; Xiao, Qin; Luo, Hongwei; Feng, Wenli

2017-03-02

The gradual emerging of resistance to imatinib urgently calls for the development of new therapy for chronic myeloid leukemia (CML). The fusion protein Bcr-Abl, which promotes the malignant transformation of CML cells, is mainly located in the cytoplasm, while the c-Abl protein which is expressed in the nucleus can induce apoptosis. Based on the hetero-dimerization of FKBP (the 12-kDa FK506- and rapamycin-binding protein) and FRB (the FKBP-rapamycin binding domain of the protein kinase, mTOR) mediated by AP21967, we constructed a nuclear transport system to induce cytoplasmic Bcr-Abl into nuclear. In this study, we reported the construction of the nuclear transport system, and we demonstrated that FN3R (three nuclear localization signals were fused to FRBT2098L with a FLAG tag), HF2S (two FKBP domains were in tandem and fused to the SH2 domain of Grb2 with an HA tag) and Bcr-Abl form a complexus upon AP21967. Bcr-Abl was imported into the nucleus successfully by the nuclear transport system. The nuclear transport system inhibited CML cell proliferation through mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 5 (STAT5) pathways mainly by HF2S. It was proven that nuclear located Bcr-Abl induced CML cell (including imatinib-resistant K562G01 cells) apoptosis by activation of p73 and its downstream molecules. In summary, our study provides a new targeted therapy for the CML patients even with Tyrosine Kinase Inhibitor (TKI)-resistance.

Inhibition of the NADPH oxidase regulates HO-1 expression in chronic myeloid leukemia

PubMed Central

Singh, Melissa M.; Irwin, Mary E.; Gao, Yin; Ban, Kechen; Shi, Ping; Arlinghaus, Ralph B.; Amin, Hesham M.; Chandra, Joya

2011-01-01

Background Patients with blast crisis phase chronic myelogeneous leukemia (CML) have poor response to tyrosine kinase inhibitors designed to inhibit the BCR-ABL1 oncogene. Recent work has shown that heme oxygenase 1 (HO-1) expression is increased in BCR-ABL1 expressing cells and that inhibition of HO-1 in CML leads to reduced cellular growth suggesting HO-1 may be a plausible target for therapy. Here we sought to clarify the mechanism of HO-1 overexpression and the role of the NADPH oxidase as a contributor to this mechanism in CML. Methods HO-1 expression was evaluated in CML bone marrow specimens from patients in various stages of disease, in a transplant based model for CML and in CML cell lines. Chemical and genetic inhibition of the NADPH oxidase was carried out in CML cells. Results Blast crisis CML patient specimens displayed higher levels of HO-1 staining than chronic or accelerated phase. HO-1 upregulation in BCR-ABL1 expressing cells was suppressed by diphenyliodonium (DPI), a chemical inhibitor of the NADPH oxidase. Targeting the NADPH oxidase through RNAi to Rac1, a dominant negative Rac1 construct or an inhibitor of Rac1 activity also blunted HO-1 protein expression. Moreover, inhibition of the NADPH oxidase by RNAi directed towards p47phox similarly abrogated HO-1 levels. Conclusion BCR-ABL1 expression upregulates HO-1, a survival factor for CML cells. This upregulation is more pronounced in blast crisis CML relative to early stage disease and is mediated by the NADPH oxidase components Rac1 and p47phox. Expression of p47phox is increased in BCR-ABL1 expressing cells. PMID:22139798

[Detection of bcr/abl fusion gene and its derivative chromosome 9 deletions in CML by using home-made bcr/abl extra-signal probe].

PubMed

Lai, Yue-Yun; Feng, Lin; Wang, Zheng; Lü, Shan; Dang, Hui; Shi, Yan; He, Qi; Huang, Xiao-Jun

2010-02-01

This study was aimed to verify the efficacy of home-made LSI bcr/abl ES probe for detection of bcr/abl fusion gene and derivative chromosome 9 deletions in chronic myeloid leukemia (CML). Fluorescence in situ hybridization (FISH) was carried out with dual color bcr/abl extra signal (ES) probe in 97 cases of CML based on morphology and cytogenetic karyotype and 129 cases of non-hematological malignancies/non-myeloproliferative diseases with normal cytogenetic karyotype. For the patients with signals of 1R1G1F indicating der(9) deletions, FISH were done using ASS DNA probe. The results showed that 91 cases with standard t(9;22) and 6 cases with variant translocation of t(9;22) were detected by conventional G banding technique. All of the 97 patients displayed bcr/abl fusion gene by ES-FISH, including 16 cases with signal patterns of 1R1G1F showing der(9) deletions. Among the 16 cases with der(9) deletions, 13 cases were detected to have deletions of ASS gene. Meanwhile, none of the 129 cases of negative control showed bcr/abl fusion gene by ES-FISH. It is concluded that home-made LSI bcr/abl ES probe is effective to identify the bcr/abl fusion gene and der(9) deletions in CML, and the ES-FISH results are consistent with conventional cytogenetic karyotype.

The Rho-ROCK pathway as a new pathological mechanism of innate immune subversion in chronic myeloid leukaemia.

PubMed

Basbous, Sara; Levescot, Anaïs; Piccirilli, Nathalie; Brizard, Françoise; Guilhot, François; Roy, Lydia; Bourmeyster, Nicolas; Gombert, Jean-Marc; Herbelin, André

2016-11-01

CD1d-restricted invariant natural killer T (iNKT) cells are believed to play a key role in cancer immune surveillance, and are functionally deficient in patients with chronic myeloid leukaemia (CML). Herein, we have hypothesized that this defect might originate from BCR-ABL-dependent dysfunctions in myeloid dendritic cells (mDCs). Indeed, flow cytometry and confocal microscopy revealed that cell surface expression of CD1d was downregulated in CML mDCs, relative to healthy donor (HD) controls. The decreased cell surface display of CD1d could not be ascribed to defective mDC differentiation, as attested by normal expression of HLA-DR and the CD86 maturation marker. On the other hand, reduced membrane expression was not associated with decreased intracytoplasmic levels of CD1d or its mRNA transcripts, consistent with intracellular retention. In vitro treatment of CML mDCs with the Rho-associated protein kinase (ROCK) inhibitor Y-27632 partially restored both cell surface CD1d expression and CD1d-mediated antigen presentation, whereas it had no effect on HD mDCs. An inhibitor of BCR-ABL tyrosine kinase (TK), imatinib mesylate (IM), had no such activity. Similar recovery of CD1d expression occurred with fasudil, another ROCK inhibitor that is commonly used in clinical trials. Our data support the conclusion that BCR-ABL-dependent ROCK, but not TK, is involved in CD1d downregulation. We propose that ROCK, which is most likely activated by the DH/PH domain of BCR-ABL, mediates iNKT-cell immune subversion in CML patients by downregulating CD1d expression on CML mDCs. Our study reveals the ROCK-mDC axis as a new potential target to restore immune surveillance in patients with CML, offering new therapeutic perspectives for CML treatment. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The Bcr-Abl kinase regulates the actin cytoskeleton via a GADS/Slp-76/Nck1 adaptor protein pathway.

PubMed

Preisinger, Christian; Kolch, Walter

2010-05-01

Bcr-Abl is the transforming principle underlying chronic myelogenous leukaemia (CML). Here, we use a functional interaction proteomics approach to map pathways by which Bcr-Abl regulates defined cellular processes. The results show that Bcr-Abl regulates the actin cytoskeleton and non-apoptotic membrane blebbing via a GADS/Slp-76/Nck1 adaptor protein pathway. The binding of GADS to Bcr-Abl requires Bcr-Abl tyrosine kinase activity and is sensitive to the Bcr-Abl inhibitor imatinib, while the GADS/Slp-76 and Slp-76/Nck interactions are tyrosine phosphorylation independent. All three adaptor proteins co-localize with cortical actin in membrane blebs. Downregulation of each adaptor protein disrupts the actin cytoskeleton and membrane blebbing in a similar fashion and similar to imatinib. These findings highlight the importance of protein interaction dependent adaptor protein pathways in oncogenic kinase signaling. 2010 Elsevier Inc. All rights reserved.

Suppression of bcr-abl synthesis by siRNAs or tyrosine kinase activity by Glivec alters different oncogenes, apoptotic/antiapoptotic genes and cell proliferation factors (microarray study).

PubMed

Zhelev, Zhivko; Bakalova, Rumiana; Ohba, Hideki; Ewis, Ashraf; Ishikawa, Mitsuru; Shinohara, Yasuo; Baba, Yoshinobu

2004-07-16

Short 21-mer double-stranded/small-interfering RNAs (ds/siRNAs) were designed to target bcr-abl mRNA in chronic myelogenous leukemia. The ds/siRNAs were transfected into bcr-abl-positive K-562 (derived from blast crisis chronic myelogenous leukemia), using lipofectamine. Penetrating of ds/siRNAs into the cells was detected by fluorescent confocal microscopy, using fluorescein-labeled ds/siRNAs. The cells were treated with mix of three siRNA sequences (3 x 60 nM) during 6 days with three repetitive transfections. The siRNA-treatment was accompanied with significant reduction of bcr-abl mRNA, p210, protein tyrosine kinase activity and cell proliferation index. Treatment of cells with Glivec (during 8 days with four repetitive doses, 180 nM single dose) resulted in analogous reduction of cell proliferation activity, stronger suppression of protein tyrosine kinase activity, and very low reduction of p210. siRNA-mix and Glivec did not affect significantly the viability of normal lymphocytes. Microarray analysis of siRNA- and Glivec-treated K-562 cells demonstrated that both pathways of bcr-abl suppression were accompanied with overexpression and suppression of many different oncogenes, apoptotic/antiapoptotic and cell proliferation factors. The following genes of interest were found to decrease in relatively equal degree in both siRNA- and Glivec-treated cells: Bcd orf1 and orf2 proto-oncogene, chromatin-specific transcription elongation factor FACT 140-kDa subunit mRNA, gene encoding splicing factor SF1, and mRNA for Tec protein tyrosine kinase. siRNA-mix and Glivec provoked overexpression of the following common genes: c-jun proto-oncogene, protein kinase C-alpha, pvt-1 oncogene homologue (myc activator), interleukin-6, 1-8D gene from interferon-inducible gene family, tumor necrosis factor receptor superfamily (10b), and STAT-induced STAT inhibitor.

Increased peroxisome proliferator-activated receptor γ activity reduces imatinib uptake and efficacy in chronic myeloid leukemia mononuclear cells

PubMed Central

Wang, Jueqiong; Lu, Liu; Kok, Chung H.; Saunders, Verity A.; Goyne, Jarrad M.; Dang, Phuong; Leclercq, Tamara M.; Hughes, Timothy P.; White, Deborah L.

2017-01-01

Imatinib is actively transported by organic cation transporter-1 (OCT-1) influx transporter, and low OCT-1 activity in diagnostic chronic myeloid leukemia blood mononuclear cells is significantly associated with poor molecular response to imatinib. Herein we report that, in diagnostic chronic myeloid leukemia mononuclear cells and BCR-ABL1+ cell lines, peroxisome proliferator-activated receptor γ agonists (GW1929, rosiglitazone, pioglitazone) significantly decrease OCT-1 activity; conversely, peroxisome proliferator-activated receptor γ antagonists (GW9662, T0070907) increase OCT-1 activity. Importantly, these effects can lead to corresponding changes in sensitivity to BCR-ABL kinase inhibition. Results were confirmed in peroxisome proliferator-activated receptor γ-transduced K562 cells. Furthermore, we identified a strong negative correlation between OCT-1 activity and peroxisome proliferator-activated receptor γ transcriptional activity in diagnostic chronic myeloid leukemia patients (n=84; P<0.0001), suggesting that peroxisome proliferator-activated receptor γ activation has a negative impact on the intracellular uptake of imatinib and consequent BCR-ABL kinase inhibition. The inter-patient variability of peroxisome proliferator-activated receptor γ activation likely accounts for the heterogeneity observed in patient OCT-1 activity at diagnosis. Recently, the peroxisome proliferator-activated receptor γ agonist pioglitazone was reported to act synergistically with imatinib, targeting the residual chronic myeloid leukemia stem cell pool. Our findings suggest that peroxisome proliferator-activated receptor γ ligands have differential effects on circulating mononuclear cells compared to stem cells. Since the effect of peroxisome proliferator-activated receptor γ activation on imatinib uptake in mononuclear cells may counteract the clinical benefit of this activation in stem cells, caution should be applied when combining these therapies, especially in patients with high peroxisome proliferator-activated receptor γ transcriptional activity. PMID:28154092

Molecular analysis of the BCR-ABL1 kinase domain in chronic-phase chronic myelogenous leukemia treated with tyrosine kinase inhibitors in practice: study by the Nagasaki CML Study Group.

PubMed

Itonaga, Hidehiro; Tsushima, Hideki; Imanishi, Daisuke; Hata, Tomoko; Doi, Yuko; Mori, Sayaka; Sasaki, Daisuke; Hasegawa, Hiroo; Matsuo, Emi; Nakashima, Jun; Kato, Takeharu; Horai, Makiko; Taguchi, Masataka; Matsuo, Masatoshi; Taniguchi, Hiroaki; Makiyama, Junnya; Sato, Shinya; Horio, Kensuke; Ando, Koji; Moriwaki, Yuji; Sawayama, Yasushi; Ogawa, Daisuke; Yamasaki, Reishi; Takasaki, Yumi; Imaizumi, Yoshitaka; Taguchi, Jun; Kawaguchi, Yasuhisa; Yoshida, Shinichiro; Joh, Tatsuro; Moriuchi, Yukiyoshi; Nonaka, Hiroaki; Soda, Hisashi; Fukushima, Takuya; Nagai, Kazuhiro; Kamihira, Shimeru; Tomonaga, Masao; Yanagihara, Katsunori; Miyazaki, Yasushi

2014-01-01

An appropriate trigger for BCR-ABL1 mutation analysis has not yet been established in unselected cohorts of chronic-phase chronic myelogenous leukemia patients. We examined 92 patients after 12 months of tyrosine kinase inhibitor (TKI) treatment in Nagasaki Prefecture, Japan. Univariate analysis revealed that significant factors associated with not attaining a major molecular response (MMR) were the presence of the minor BCR-ABL1 fusion gene, a low daily dose of TKI, and the emergence of BCR-ABL1 kinase domain mutations conferring resistance to imatinib. Factors associated with the loss of sustained MMR were a low daily dose of TKI and the emergence of alternatively spliced BCR-ABL1 mRNA with a 35-nucleotide insertion. Taken together, our results suggest that the search for BCR-ABL1 mutations should be initiated if patients have not achieved MMR following 12 months of TKI treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

EFFECT OF THAI SARAPHI FLOWER EXTRACTS ON WT1 AND BCR/ABL PROTEIN EXPRESSION IN LEUKEMIC CELL LINES.

PubMed

Sangkaruk, Rungkarn; Rungrojsakul, Methee; Tima, Singkome; Anuchapreeda, Songyot

2017-01-01

Saraphi (Mammea siamensis) is a Thai traditional herb. In this study, the cytotoxic effects of crude ethanolic and fractional extracts including hexane, ethyl acetate, and methanol fractions from M. siamensis flowers were investigated in order to determine their effect on WT1 expression in Molt4 and K562 cells and Bcr/Abl expression in K562 cells. The flowers of M. siamensis were extracted using ethanol. The ethanol flower extract was further fractionated with hexane, ethyl acetate, and methanol. Cytotoxic effects were measured by the MTT assay. Bcr/Abl and WT1 protein levels after treatments were determined by Western blotting. The total cell number was determined via the typan blue exclusion method. The hexane fraction showed the strongest cytotoxic activity on Molt4 and K562 cells, with IC 50 values of 2.6 and 77.6 μg/ml, respectively. The hexane extract decreased Bcr/Abl protein expression in K562 cells by 74.6% and WT1 protein expressions in Molt4 and K562 cells by 68.4 and 72.1%, respectively. Total cell numbers were decreased by 66.2 and 48.7% in Molt4 and K562 cells, respectively. Mammea E/BB (main active compound) significantly decreased both Bcr/Abl and WTlprotein expressions by 75 and 49.5%, respectively when compared to vehicle control. The hexane fraction from M. siamensis flowers inhibited cell proliferation via the suppression of WT1 expression in Molt4 and K562 cells and Bcr/Abl expression in K562 cells. The active compound may be mammea E/BB. Extracts from M. siamensis flowers show promise as naturally occurring anti-cancer drugs.

MEK-Dependent Negative Feedback Underlies BCR-ABL-Mediated Oncogene Addiction

PubMed Central

Asmussen, Jennifer; Lasater, Elisabeth A.; Tajon, Cheryl; Oses-Prieto, Juan; Jun, Young-wook; Taylor, Barry S.; Burlingame, Alma; Craik, Charles S.; Shah, Neil P.

2014-01-01

The clinical experience with BCR-ABL tyrosine kinase inhibitors (TKIs) for the treatment of chronic myeloid leukemia (CML) provides compelling evidence for oncogene addiction. Yet, the molecular basis of oncogene addiction remains elusive. Through unbiased quantitative phosphoproteomic analyses of CML cells transiently exposed to BCR-ABL TKI, we identified persistent downregulation of growth factor receptor (GF-R) signaling pathways. We then established and validated a tissue-relevant isogenic model of BCR-ABL-mediated addiction, and found evidence for myeloid GF-R signaling pathway rewiring that profoundly and persistently dampens physiologic pathway activation. We demonstrate that eventual restoration of ligand-mediated GF-R pathway activation is insufficient to fully rescue cells from a competing apoptotic fate. In contrast to previous work with BRAFV600E in melanoma cells, feedback inhibition following BCR-ABL TKI treatment is markedly prolonged, extending beyond the time required to initiate apoptosis. Mechanistically, BCR-ABL-mediated oncogene addiction is facilitated by persistent high levels of MEK-dependent negative feedback. PMID:24362263

A multiple reaction monitoring (MRM) method to detect Bcr-Abl kinase activity in CML using a peptide biosensor.

PubMed

Yang, Tzu-Yi; Eissler, Christie L; Hall, Mark C; Parker, Laurie L

2013-01-01

The protein kinase Bcr-Abl plays a major role in the pathogenesis of chronic myelogenous leukemia (CML), and is the target of the breakthrough drug imatinib (Gleevec™). While most patients respond well to imatinib, approximately 30% never achieve remission or develop resistance within 1-5 years of starting imatinib treatment. Evidence from clinical studies suggests that achieving at least 50% inhibition of a patient's Bcr-Abl kinase activity (relative to their level at diagnosis) is associated with improved patient outcomes, including reduced occurrence of resistance and longer maintenance of remission. Accordingly, sensitive assays for detecting Bcr-Abl kinase activity compatible with small amounts of patient material are desirable as potential companion diagnostics for imatinib. Here we report the detection of Bcr-Abl activity and inhibition by imatinib in the human CML cell line K562 using a cell-penetrating peptide biosensor and multiple reaction monitoring (MRM) on a triple quadrupole mass spectrometer. MRM enabled reproducible, selective detection of the peptide biosensor at fmol levels from aliquots of cell lysate equivalent to ~15,000 cells. This degree of sensitivity will facilitate the miniaturization of the entire assay procedure down to cell numbers approaching 15,000, making it practical for translational applications in patient cells in which the limited amount of available patient material often presents a major challenge.

A Multiple Reaction Monitoring (MRM) Method to Detect Bcr-Abl Kinase Activity in CML Using a Peptide Biosensor

PubMed Central

Yang, Tzu-Yi; Eissler, Christie L.; Hall, Mark C.; Parker, Laurie L.

2013-01-01

The protein kinase Bcr-Abl plays a major role in the pathogenesis of chronic myelogenous leukemia (CML), and is the target of the breakthrough drug imatinib (Gleevec™). While most patients respond well to imatinib, approximately 30% never achieve remission or develop resistance within 1–5 years of starting imatinib treatment. Evidence from clinical studies suggests that achieving at least 50% inhibition of a patient’s Bcr-Abl kinase activity (relative to their level at diagnosis) is associated with improved patient outcomes, including reduced occurrence of resistance and longer maintenance of remission. Accordingly, sensitive assays for detecting Bcr-Abl kinase activity compatible with small amounts of patient material are desirable as potential companion diagnostics for imatinib. Here we report the detection of Bcr-Abl activity and inhibition by imatinib in the human CML cell line K562 using a cell-penetrating peptide biosensor and multiple reaction monitoring (MRM) on a triple quadrupole mass spectrometer. MRM enabled reproducible, selective detection of the peptide biosensor at fmol levels from aliquots of cell lysate equivalent to ∼15,000 cells. This degree of sensitivity will facilitate the miniaturization of the entire assay procedure down to cell numbers approaching 15,000, making it practical for translational applications in patient cells in which the limited amount of available patient material often presents a major challenge. PMID:23437189

BCR-ABL1 expression, RT-qPCR and treatment decisions in chronic myeloid leukaemia.

PubMed

Latham, Susan; Bartley, Paul A; Budgen, Bradley; Ross, David M; Hughes, Elizabeth; Branford, Susan; White, Deborah; Hughes, Timothy P; Morley, Alexander A

2016-09-01

RT-qPCR is used to quantify minimal residual disease (MRD) in chronic myeloid leukaemia (CML) in order to make decisions on treatment, but its results depend on the level of BCR-ABL1 expression as well as leukaemic cell number. The aims of the study were to quantify inter-individual differences in expression level, to determine the relationship between expression level and response to treatment, and to investigate the effect of expression level on interpretation of the RT-qPCR result. BCR-ABL1 expression was studied in 248 samples from 65 patients with CML by determining the difference between MRD quantified by RT-qPCR and DNA-qPCR. The results were analysed statistically and by simple indicative modelling. Inter-individual levels of expression approximated a normal distribution with an SD of 0.36 log. Expression at diagnosis correlated with expression during treatment. Response to treatment, as measured by the number of leukaemic cells after 3, 6 or 12 months of treatment, was not related to the level of expression. Indicative modelling suggested that interpretation of RT-qPCR results in relation to treatment guidelines could be affected by variation in expression when MRD was around 10% at 3 months and by both expression variation and Poisson variation when MRD was around or below the limit of detection of RT-qPCR. Variation between individuals in expression of BCR-ABL1 can materially affect interpretation of the RT-qPCR when this test is used to make decisions on treatment. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Beneficial effects of combining nilotinib and imatinib in preclinical models of BCR-ABL+ leukemias

PubMed Central

Weisberg, Ellen; Catley, Laurie; Wright, Renee D.; Moreno, Daisy; Banerji, Lolita; Ray, Arghya; Manley, Paul W.; Mestan, Juergen; Fabbro, Doriano; Jiang, Jingrui; Hall-Meyers, Elizabeth; Callahan, Linda; DellaGatta, Jamie L.; Kung, Andrew L.

2007-01-01

Drug resistance resulting from emergence of imatinib-resistant BCR-ABL point mutations is a significant problem in advanced-stage chronic myelogenous leukemia (CML). The BCR-ABL inhibitor, nilotinib (AMN107), is significantly more potent against BCR-ABL than imatinib, and is active against many imatinib-resistant BCR-ABL mutants. Phase 1/2 clinical trials show that nilotinib can induce remissions in patients who have previously failed imatinib, indicating that sequential therapy with these 2 agents has clinical value. However, simultaneous, rather than sequential, administration of 2 BCR-ABL kinase inhibitors is attractive for many reasons, including the theoretical possibility that this could reduce emergence of drug-resistant clones. Here, we show that exposure of a variety of BCR-ABL+ cell lines to imatinib and nilotinib results in additive or synergistic cytotoxicity, including testing of a large panel of cells expressing BCR-ABL point mutations causing resistance to imatinib in patients. Further, using a highly quantifiable bioluminescent in vivo model, drug combinations were at least additive in antileukemic activity, compared with each drug alone. These results suggest that despite binding to the same site in the same target kinase, the combination of imatinib and nilotinib is highly efficacious in these models, indicating that clinical testing of combinations of BCR-ABL kinase inhibitors is warranted. PMID:17068153

Proteomic-based identification of Apg-2 as a therapeutic target for chronic myeloid leukemia.

PubMed

Li, Yajuan; Chen, Xi; Shi, Meng; Wang, Haixia; Cao, Weixi; Wang, Xiaozhong; Li, Chunli; Feng, Wenli

2013-12-01

The oncogenic BCR/ABL tyrosine kinase induces constitutive enhanced "spontaneous" DNA damage and unfaithful repair in Philadelphia chromosome positive leukemia cells. Here, we investigated the changes of protein profile in H2O2-induced DNA damage/repair in BaF3-MIGR1 and BaF3-BCR/ABL cells through a proteomic strategy consisting of two-dimensional gel electrophoresis (2-DE) coupled with MALDI-TOF mass spectrometry. In total, 41 spots were differentially expressed and 13 proteins were identified with further MS analysis. Two essential proteins, Proto-oncogene tyrosine-protein kinase ABL1 (c-ABL) and Heat shock 70kDa protein 4 (Apg-2), were confirmed by Western blot and showed consistent changes with proteomic results. Moreover, functional analysis demonstrated that inhibition of Apg-2 not only decreased cell proliferation, but also induced cell apoptosis in BCR/ABL positive cells (BaF3-BCR/ABL, BaF3-BCR/ABL(T315I)). We also proved that Apg-2 inhibition aggravated H2O2 induced damage in BCR/ABL positive cells, and enhanced the sensitivity of BaF3-BCR/ABL(T315I) to STI571. Taken together, the findings in this work provide us with some clues to a better understanding of the molecular mechanisms underlying BCR/ABL in the DNA damage/repair processes and demonstrated that Apg-2 would be a valid target for anti-leukemia drug development. © 2013.

Population-based Testing and Treatment Characteristics for Chronic Myelogenous Leukemia

PubMed Central

Styles, Timothy; Wu, Manxia; Wilson, Reda; Babcock, Frances; Butterworth, David; West, Dee W.; Richardson, Lisa C.

2017-01-01

Introduction National and International Hematology/Oncology Practice Guidelines recommend testing for the BCR-ABL mutation for definitive diagnosis of chronic myeloid leukemia (CML) to allow for appropriate treatment with a Tyrosine Kinase Inhibitor (TKI). The purpose of our study was to describe population-based testing and treatment practice characteristics for patients diagnosed with CML. Methods We analyzed cases of CML using 2011 data from 10 state registries which are part of the Centers for Disease Control and Prevention’s (CDC) National Program of Cancer Registries. We describe completeness of testing for the BCR-ABL gene and availability of outpatient treatment with TKIs and associated characteristics. Results A total of 685 cases of CML were identified; 55% (374) had a documented BCR-ABL gene test with 96% (360) of these being positive for the BCR-ABL gene and the remaining 4% (14) either testing negative or had a missing result. Registries were able to identify the use of TKIs in 54% (369) of patients, though only 43% (296) had a corresponding BCR-ABL gene test documented. One state registry reported a significantly lower percentage of patients being tested for the BCR-ABL gene (25%) and receiving TKI treatment (21%). Limiting analysis to CML case reports from the remaining nine CER registries, 78% (305) patients had a documented BCR-ABL gene test and 79% (308) had documented treatment with a TKI. Receipt of testing or treatment for these nine states did not vary by sex, race, ethnicity, census tract poverty level, census tract urbanization, or insurance status; BCR-ABL testing varied by state of residence and BCR-ABL testing and TKI therapy occurred less often with increasing age (OR: 0.97, 95%CI: 0.95–0.99; OR: 0.97, 95%CI: 0.96–0.99 respectively). Conclusions Collection of detailed CML data vary significantly by states. A majority of the case patients had appropriate testing for the BCR-ABL gene and treatment with tyrosine kinase inhibitors. However, BCR-ABL testing and TKI treatment decreased with increasing age. Further research is needed to understand CML coding, testing, and treatment disparities. PMID:28121314

Prevalence of gene rearrangements in Mexican children with acute lymphoblastic leukemia: a population study-report from the Mexican Interinstitutional Group for the identification of the causes of childhood leukemia.

PubMed

Bekker-Méndez, Vilma Carolina; Miranda-Peralta, Enrique; Núñez-Enríquez, Juan Carlos; Olarte-Carrillo, Irma; Guerra-Castillo, Francisco Xavier; Pompa-Mera, Ericka Nelly; Ocaña-Mondragón, Alicia; Rangel-López, Angélica; Bernáldez-Ríos, Roberto; Medina-Sanson, Aurora; Jiménez-Hernández, Elva; Amador-Sánchez, Raquel; Peñaloza-González, José Gabriel; de Diego Flores-Chapa, José; Fajardo-Gutiérrez, Arturo; Flores-Lujano, Janet; Rodríguez-Zepeda, María Del Carmen; Dorantes-Acosta, Elisa María; Bolea-Murga, Victoria; Núñez-Villegas, Nancy; Velázquez-Aviña, Martha Margarita; Torres-Nava, José Refugio; Reyes-Zepeda, Nancy Carolina; González-Bonilla, Cesar; Mejía-Aranguré, Juan Manuel

2014-01-01

Mexico has one of the highest incidences of childhood leukemia worldwide and significantly higher mortality rates for this disease compared with other countries. One possible cause is the high prevalence of gene rearrangements associated with the etiology or with a poor prognosis of childhood acute lymphoblastic leukemia (ALL). The aims of this multicenter study were to determine the prevalence of the four most common gene rearrangements [ETV6-RUNX1, TCF3-PBX1, BCR-ABL1, and MLL rearrangements] and to explore their relationship with mortality rates during the first year of treatment in ALL children from Mexico City. Patients were recruited from eight public hospitals during 2010-2012. A total of 282 bone marrow samples were obtained at each child's diagnosis for screening by conventional and multiplex reverse transcription polymerase chain reaction to determine the gene rearrangements. Gene rearrangements were detected in 50 (17.7%) patients. ETV6-RUNX1 was detected in 21 (7.4%) patients, TCF3-PBX1 in 20 (7.1%) patients, BCR-ABL1 in 5 (1.8%) patients, and MLL rearrangements in 4 (1.4%) patients. The earliest deaths occurred at months 1, 2, and 3 after diagnosis in patients with MLL, ETV6-RUNX1, and BCR-ABL1 gene rearrangements, respectively. Gene rearrangements could be related to the aggressiveness of leukemia observed in Mexican children.

Prevalence of Gene Rearrangements in Mexican Children with Acute Lymphoblastic Leukemia: A Population Study—Report from the Mexican Interinstitutional Group for the Identification of the Causes of Childhood Leukemia

PubMed Central

Bekker-Méndez, Vilma Carolina; Miranda-Peralta, Enrique; Núñez-Enríquez, Juan Carlos; Olarte-Carrillo, Irma; Guerra-Castillo, Francisco Xavier; Pompa-Mera, Ericka Nelly; Ocaña-Mondragón, Alicia; Bernáldez-Ríos, Roberto; Medina-Sanson, Aurora; Jiménez-Hernández, Elva; Amador-Sánchez, Raquel; Peñaloza-González, José Gabriel; de Diego Flores-Chapa, José; Fajardo-Gutiérrez, Arturo; Flores-Lujano, Janet; Rodríguez-Zepeda, María del Carmen; Dorantes-Acosta, Elisa María; Bolea-Murga, Victoria; Núñez-Villegas, Nancy; Velázquez-Aviña, Martha Margarita; Torres-Nava, José Refugio; Reyes-Zepeda, Nancy Carolina; González-Bonilla, Cesar; Mejía-Aranguré, Juan Manuel

2014-01-01

Mexico has one of the highest incidences of childhood leukemia worldwide and significantly higher mortality rates for this disease compared with other countries. One possible cause is the high prevalence of gene rearrangements associated with the etiology or with a poor prognosis of childhood acute lymphoblastic leukemia (ALL). The aims of this multicenter study were to determine the prevalence of the four most common gene rearrangements [ETV6-RUNX1, TCF3-PBX1, BCR-ABL1, and MLL rearrangements] and to explore their relationship with mortality rates during the first year of treatment in ALL children from Mexico City. Patients were recruited from eight public hospitals during 2010–2012. A total of 282 bone marrow samples were obtained at each child's diagnosis for screening by conventional and multiplex reverse transcription polymerase chain reaction to determine the gene rearrangements. Gene rearrangements were detected in 50 (17.7%) patients. ETV6-RUNX1 was detected in 21 (7.4%) patients, TCF3-PBX1 in 20 (7.1%) patients, BCR-ABL1 in 5 (1.8%) patients, and MLL rearrangements in 4 (1.4%) patients. The earliest deaths occurred at months 1, 2, and 3 after diagnosis in patients with MLL, ETV6-RUNX1, and BCR-ABL1 gene rearrangements, respectively. Gene rearrangements could be related to the aggressiveness of leukemia observed in Mexican children. PMID:25692130

The Functional Interplay Between the t(9;22)-Associated Fusion Proteins BCR/ABL and ABL/BCR in Philadelphia Chromosome-Positive Acute Lymphatic Leukemia

PubMed Central

Rafiei, Anahita; Mian, Afsar Ali; Döring, Claudia; Metodieva, Anna; Oancea, Claudia; Thalheimer, Frederic B.; Hansmann, Martin Leo; Ottmann, Oliver Gerhard; Ruthardt, Martin

2015-01-01

The hallmark of Philadelphia chromosome positive (Ph+) leukemia is the BCR/ABL kinase, which is successfully targeted by selective ATP competitors. However, inhibition of BCR/ABL alone is unable to eradicate Ph+ leukemia. The t(9;22) is a reciprocal translocation which encodes not only for the der22 (Philadelphia chromosome) related BCR/ABL, but also for der9 related ABL/BCR fusion proteins, which can be detected in 65% of patients with chronic myeloid leukemia (CML) and 100% of patients with Ph+ acute lymphatic leukemia (ALL). ABL/BCRs are oncogenes able to influence the lineage commitment of hematopoietic progenitors. Aim of this study was to further disclose the role of p96ABL/BCR for the pathogenesis of Ph+ ALL. The co-expression of p96ABL/BCR enhanced the kinase activity and as a consequence, the transformation potential of p185BCR/ABL. Targeting p96ABL/BCR by RNAi inhibited growth of Ph+ ALL cell lines and Ph+ ALL patient-derived long-term cultures (PD-LTCs). Our in vitro and in vivo stem cell studies further revealed a functional hierarchy of p96ABL/BCR and p185BCR/ABL in hematopoietic stem cells. Co-expression of p96ABL/BCR abolished the capacity of p185BCR/ABL to induce a CML-like disease and led to the induction of ALL. Taken together our here presented data reveal an important role of p96ABL/BCR for the pathogenesis of Ph+ ALL. PMID:25919613

Characterization of leukemias with ETV6-ABL1 fusion

PubMed Central

Zaliova, Marketa; Moorman, Anthony V.; Cazzaniga, Giovanni; Stanulla, Martin; Harvey, Richard C.; Roberts, Kathryn G.; Heatley, Sue L.; Loh, Mignon L.; Konopleva, Marina; Chen, I-Ming; Zimmermannova, Olga; Schwab, Claire; Smith, Owen; Mozziconacci, Marie-Joelle; Chabannon, Christian; Kim, Myungshin; Frederik Falkenburg, J. H.; Norton, Alice; Marshall, Karen; Haas, Oskar A.; Starkova, Julia; Stuchly, Jan; Hunger, Stephen P.; White, Deborah; Mullighan, Charles G.; Willman, Cheryl L.; Stary, Jan; Trka, Jan; Zuna, Jan

2016-01-01

To characterize the incidence, clinical features and genetics of ETV6-ABL1 leukemias, representing targetable kinase-activating lesions, we analyzed 44 new and published cases of ETV6-ABL1-positive hematologic malignancies [22 cases of acute lymphoblastic leukemia (13 children, 9 adults) and 22 myeloid malignancies (18 myeloproliferative neoplasms, 4 acute myeloid leukemias)]. The presence of the ETV6-ABL1 fusion was ascertained by cytogenetics, fluorescence in-situ hybridization, reverse transcriptase-polymerase chain reaction and RNA sequencing. Genomic and gene expression profiling was performed by single nucleotide polymorphism and expression arrays. Systematic screening of more than 4,500 cases revealed that in acute lymphoblastic leukemia ETV6-ABL1 is rare in childhood (0.17% cases) and slightly more common in adults (0.38%). There is no systematic screening of myeloproliferative neoplasms; however, the number of ETV6-ABL1-positive cases and the relative incidence of acute lymphoblastic leukemia and myeloproliferative neoplasms suggest that in adulthood ETV6-ABL1 is more common in BCR-ABL1-negative chronic myeloid leukemia-like myeloproliferations than in acute lymphoblastic leukemia. The genomic profile of ETV6-ABL1 acute lymphoblastic leukemia resembled that of BCR-ABL1 and BCR-ABL1-like cases with 80% of patients having concurrent CDKN2A/B and IKZF1 deletions. In the gene expression profiling all the ETV6-ABL1-positive samples clustered in close vicinity to BCR-ABL1 cases. All but one of the cases of ETV6-ABL1 acute lymphoblastic leukemia were classified as BCR-ABL1-like by a standardized assay. Over 60% of patients died, irrespectively of the disease or age subgroup examined. In conclusion, ETV6-ABL1 fusion occurs in both lymphoid and myeloid leukemias; the genomic profile and clinical behavior resemble BCR-ABL1-positive malignancies, including the unfavorable prognosis, particularly of acute leukemias. The poor outcome suggests that treatment with tyrosine kinase inhibitors should be considered for patients with this fusion. PMID:27229714

The First Pentacyclic Triterpenoid Gypsogenin Derivative Exhibiting Anti-ABL1 Kinase and Anti-chronic Myelogenous Leukemia Activities.

PubMed

Ciftci, Halil Ibrahim; Ozturk, Safiye Emirdag; Ali, Taha F S; Radwan, Mohamed O; Tateishi, Hiroshi; Koga, Ryoko; Ocak, Zeynep; Can, Mustafa; Otsuka, Masami; Fujita, Mikako

2018-04-01

The discovery of the chimeric tyrosine kinase breakpoint cluster region kinase-Abelson kinase (BCR-ABL)-targeted drug imatinib conceptually changed the treatment of chronic myelogenous leukemia (CML). However, some CML patients show drug resistance to imatinib. To address this issue, some artificial heterocyclic compounds have been identified as BCR-ABL inhibitors. Here we examined whether plant-derived pentacyclic triterpenoid gypsogenin and/or their derivatives show inhibitory activity against BCR-ABL. Among the three derivatives, benzyl 3-hydroxy-23-oxoolean-12-en-28-oate (1c) was found to be the most effective anticancer agent on the CML cell line K562, with an IC 50 value of 9.3 µM. In contrast, the IC 50 against normal peripheral blood mononuclear cells was 276.0 µM, showing better selectivity than imatinib. Compound 1c had in vitro inhibitory activity against Abelson kinase 1 (ABL1) (IC 50 =8.7 µM), the kinase component of BCR-ABL. In addition, compound 1c showed a different inhibitory profile against eight kinases compared with imatinib. The interaction between ATP binding site of ABL and 1c was examined by molecular docking study, and the binding mode was different from imatinib and newer generation inhibitors. Furthermore, 1c suppressed signaling downstream of BCR-ABL. This study suggests the possibility that plant extracts may be a source for CML treatment and offer a strategy to overcome drug resistance to known BCR-ABL inhibitors.

Wnt/Ca2+/NFAT signaling maintains survival of Ph+ leukemia cells upon inhibition of Bcr-Abl

PubMed Central

Gregory, Mark A.; Phang, Tzu L.; Neviani, Paolo; Alvarez-Calderon, Francesca; Eide, Christopher A.; O’Hare, Thomas; Zaberezhnyy, Vadym; Williams, Richard T.; Druker, Brian J.; Perrotti, Danilo; DeGregori, James

2010-01-01

Summary Although Bcr-Abl kinase inhibitors have proven effective in the treatment of chronic myeloid leukemia (CML), they generally fail to completely eradicate Bcr-Abl+ leukemia cells. To identify genes whose inhibition sensitizes Bcr-Abl+ leukemias to killing by Bcr-Abl inhibitors, we performed an RNAi-based synthetic lethal screen with imatinib in CML cells. This screen identified numerous components of a Wnt/Ca2+/NFAT signaling pathway. Antagonism of this pathway led to impaired NFAT activity, decreased cytokine production and enhanced sensitivity to Bcr-Abl inhibition. Furthermore, NFAT inhibition with cyclosporin A facilitated leukemia cell elimination by the Bcr-Abl inhibitor dasatinib and markedly improved survival in a mouse model of Bcr-Abl+ acute lymphoblastic leukemia (ALL). Targeting this pathway in combination with Bcr-Abl inhibition could improve treatment of Bcr-Abl+ leukemias. PMID:20609354

Planned Pregnancy in a Chronic Myeloid Leukemia Patient in Molecular Remission

PubMed Central

Pavlovsky, Carolina; Giere, Isabel; Van Thillo, Germán

2012-01-01

Excellent response rates and a good quality of life have been observed since the introduction of tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML) treatment. Consequently, some challenges began to appear in CML women in child-bearing age wishing to become pregnant. Currently, many women around the world are in stable major/complete molecular response MMR/CMR (MMR: <0.1% BCR-ABL/ABL and CMR: undetectable BCR-ABL mRNA by RQ-PCR transcript levels on the international scale). The condition of stable MMR/CMR is linked to a long-term virtual absence of progression to the accelerated and blastic phase and to the possibility of stopping the TKI treatment with the maintenance of a condition of CMR in a proportion of cases. Imatinib teratogenic and prescribing information prohibits the use of it during pregnancy. We describe the case of a 36-year-old female patient with CML in chronic phase who stopped imatinib after 2 years in major molecular response (MMR) to plan a pregnancy. Molecular monitoring by RQ-PCR was performed quarterly. She achieved a safe pregnancy and delivery maintaining an optimal molecular response throughout the pregnancy. Isolated literature reports have been described, but no formal advice has been described at present time. PMID:22928126

BCR-ABL PCR testing in chronic myelogenous leukemia: molecular diagnosis for targeted cancer therapy and monitoring.

PubMed

Luu, Martin H; Press, Richard D

2013-09-01

The use of tyrosine kinase inhibitors (TKIs) to treat chronic myeloid leukemia (CML) represents the paradigm for modern targeted cancer therapy. Importantly, molecular monitoring using BCR-ABL real-time quantitative reverse transcription polymerase chain reaction (RQ-PCR) for assessing treatment efficacy and quantitating minimal residual disease is a major determinate of practical therapeutic decision-making in the long-term management of this now chronic disease. Herein, we present an overview of CML and the use of TKIs for targeted CML therapy, with an emphasis on the role, application and future aspects of PCR-based molecular monitoring.

Hoxa9 and Hoxa10 induce CML myeloid blast crisis development through activation of Myb expression.

PubMed

Negi, Vijay; Vishwakarma, Bandana A; Chu, Su; Oakley, Kevin; Han, Yufen; Bhatia, Ravi; Du, Yang

2017-11-17

Mechanisms underlying the progression of Chronic Myeloid Leukemia (CML) from chronic phase to myeloid blast crisis are poorly understood. Our previous studies have suggested that overexpression of SETBP1 can drive this progression by conferring unlimited self-renewal capability to granulocyte macrophage progenitors (GMPs). Here we show that overexpression of Hoxa9 or Hoxa10 , both transcriptional targets of Setbp1 , is also sufficient to induce self-renewal of primary myeloid progenitors, causing their immortalization in culture. More importantly, both are able to cooperate with BCR/ABL to consistently induce transformation of mouse GMPs and development of aggressive leukemias resembling CML myeloid blast crisis, suggesting that either gene can drive CML progression by promoting the self-renewal of GMPs. We further identify Myb as a common critical target for Hoxa9 and Hoxa10 in inducing self-renewal of myeloid progenitors as Myb knockdown significantly reduced colony-forming potential of myeloid progenitors immortalized by the expression of either gene. Interestingly, Myb is also capable of immortalizing primary myeloid progenitors in culture and cooperating with BCR/ABL to induce leukemic transformation of mouse GMPs. Significantly increased levels of MYB transcript also were detected in all human CML blast crisis samples examined over chronic phase samples, further suggesting the possibility that MYB overexpression may play a prevalent role in driving human CML myeloid blast crisis development. In summary, our results identify overexpression of HOXA9 , HOXA10 , and MYB as critical drivers of CML progression, and suggest MYB as a key therapeutic target for inhibiting the self-renewal of leukemia-initiating cells in CML myeloid blast crisis patients.

Phase I Trial of AZD1775 and Belinostat in Treating Patients With Relapsed or Refractory Myeloid Malignancies or Untreated Acute Myeloid Leukemia

ClinicalTrials.gov

2018-05-24

Acute Myeloid Leukemia; Blast Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Myelodysplastic Syndrome; Previously Treated Myelodysplastic Syndrome; Recurrent Adult Acute Myeloid Leukemia; Recurrent Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Refractory Acute Myeloid Leukemia; Refractory Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Secondary Acute Myeloid Leukemia; Therapy-Related Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

Critical roles for mTORC2- and rapamycin-insensitive mTORC1-complexes in growth and survival of BCR-ABL-expressing leukemic cells

PubMed Central

Carayol, Nathalie; Vakana, Eliza; Sassano, Antonella; Kaur, Surinder; Goussetis, Dennis J.; Glaser, Heather; Druker, Brian J.; Donato, Nicholas J.; Altman, Jessica K.; Barr, Sharon; Platanias, Leonidas C.

2010-01-01

mTOR-generated signals play critical roles in growth of leukemic cells by controlling mRNA translation of genes that promote mitogenic responses. Despite extensive work on the functional relevance of rapamycin-sensitive mTORC1 complexes, much less is known on the roles of rapamycin-insensitive (RI) complexes, including mTORC2 and RI-mTORC1, in BCR-ABL-leukemogenesis. We provide evidence for the presence of mTORC2 complexes in BCR-ABL-transformed cells and identify phosphorylation of 4E-BP1 on Thr37/46 and Ser65 as RI-mTORC1 signals in primary chronic myelogenous leukemia (CML) cells. Our studies establish that a unique dual mTORC2/mTORC1 inhibitor, OSI-027, induces potent suppressive effects on primitive leukemic progenitors from CML patients and generates antileukemic responses in cells expressing the T315I-BCR-ABL mutation, which is refractory to all BCR-ABL kinase inhibitors currently in clinical use. Induction of apoptosis by OSI-027 appears to negatively correlate with induction of autophagy in some types of BCR-ABL transformed cells, as shown by the induction of autophagy during OSI-027-treatment and the potentiation of apoptosis by concomitant inhibition of such autophagy. Altogether, our studies establish critical roles for mTORC2 and RI-mTORC1 complexes in survival and growth of BCR-ABL cells and suggest that dual therapeutic targeting of such complexes may provide an approach to overcome leukemic cell resistance in CML and Ph+ ALL. PMID:20616057

Concomitant presence of JAK2V617F mutation and BCR‑ABL translocation in two patients: A new entity or a variant of myeloproliferative neoplasms (Case report).

PubMed

Mousinho, Filipa; Azevedo, Ana P; Mendes, Tatiana; Santos, Paula Sousa E; Cerqueira, Rita; Matos, Sónia; Santos, Sónia; Ramos, Sância; Viana, João Faro; Lima, Fernando

2018-05-17

Myeloproliferative neoplasms (MPNs) are classically divided into BCR RhoGEF and GTPase activating protein (BCR)-ABL proto‑oncogene 1 non‑receptor tyrosine kinase (ABL) positive chronic myeloid leukemia (CML) and BCR‑ABL negative MPNs, including essential thrombocythemia (ET). One of the major diagnostic criteria for ET is the absence of the philadelphia chromosome, thus when present it is almost indicative of CML. ET and CML are considered to be mutually exclusive; however, there are rare situations in which patients with ET present positive BCR‑ABL without the features of CML. Although from the literature review, the frequency of JAK2V617F mutation and BCR‑ABL translocation coexistence in MPNs is low, it may be higher than expected. The current study reported cases of two patients with an initial diagnosis of ET in the presence of JAK2V617F mutation and BCR‑ABL translocation by fluorescent in situ hybridization. Both patients presented with a heterozygous BCR‑ABL translocation, and absence of p190 and p210 transcripts, seemingly a der(9) in the background of an ET JAK2V617F mutation.

CT-721, a Potent Bcr-Abl Inhibitor, Exhibits Excellent In Vitro and In Vivo Efficacy in the Treatment of Chronic Myeloid Leukemia

PubMed Central

Sun, Yinghui; Zhao, Na; Wang, Huan; Wu, Qiong; Han, Yunqi; Liu, Qichao; Wu, Mangang; Liu, Yuliang; Kong, Fansheng; Wang, He; Sun, Ying; Sun, Deguang; Jing, Lutao; Tang, Guojing; Hu, Yuandong; Xiao, Dengming; Luo, Hong; Han, Yongxin; Peng, Yong

2017-01-01

Kinase inhibitors that target Bcr-Abl are highly effective in the treatment of chronic myeloid leukemia (CML). However, these inhibitors are often invalidated due to the drug resistance. Therefore, the discovery and development of novel Bcr-Abl inhibitors is required to overwhelm the drug resistance in the treatment of CML resistant to the currently used first-line Bcr-Abl inhibitors. Herein we have described a newly developed Bcr-Abl inhibitor CT-721, which displayed potent inhibitory effects on wild-type and T315I mutant Bcr-Abl. It functioned as a typically ATP-competitive inhibitor, superior to other existing Bcr-Abl inhibitors. CT-721 also demonstrated time-dependent inhibition of Bcr-Abl activation and the resultant downstream signaling transduction pathways in Bcr-Abl positive cells. Furthermore, CT-721 induced cell apoptosis and cell cycle arrest, and efficaciously inhibited tumor growth in Bcr-Abl-expressed K562 and KU812 xenograft models in a mechanism-based manner. Further PK/PD studies revealed a positive in vivo correlation between the compound concentration and inhibition of Bcr-Abl activity. Taken together, CT-721 is a potent and time-dependent Bcr-Abl kinase inhibitor, and has shown strong in vitro and in vivo anti-CML activities with a favorable pharmacokinetic profile, differentiating it from other Bcr-Abl kinase inhibitors already approved and current in development for the treatment of CML. PMID:28928866

Outcomes of Chronic Myeloid Leukemia Patients With Early Molecular Response at 3 and 6 Months: A Comparative Analysis of Generic Imatinib and Glivec.

PubMed

Eskazan, Ahmet Emre; Sadri, Sevil; Keskin, Dilek; Ayer, Mesut; Kantarcioglu, Bulent; Demirel, Naciye; Aydin, Demet; Aydinli, Fuat; Yokus, Osman; Ozunal, Isil Erdogan; Berk, Selin; Yalniz, Fevzi Firat; Elverdi, Tugrul; Salihoglu, Ayse; Ar, Muhlis Cem; Ongoren, Seniz; Baslar, Zafer; Aydin, Yildiz; Tuzuner, Nukhet; Ozbek, Ugur; Soysal, Teoman

2017-12-01

The molecular response at 3 months of the original imatinib (OI) in patients with chronic myeloid leukemia has prognostic significance; however, this has never been tested for generic imatinib (GI). We evaluated the BCR-ABL1 [international reporting scale (IS)] transcript levels at 3 and 6 months to determine whether an early molecular response (EMR) had a prognostic effect on the outcome among chronic myeloid leukemia patients receiving GI. Ninety patients were divided into 2 groups, according to the imatinib they received, as OI (group A) and GI (group B). Two groups were equally balanced for age, gender, Sokal risk score, and optimal response. The 2 groups did not differ in achieving an EMR at 3 months, and patients with EMR at 3 months had significantly superior complete cytogenetic response and major molecular response rates compared with patients who did not achieve an EMR in both groups. The percentage of an optimal response [BCR-ABL1 (IS), < 1%] and a warning response [BCR-ABL1 (IS), 1%-10%] at 6 months was 93% and 95% for groups A and B, respectively (P = .553). Patients with an optimal response (OR) at both 3 and 6 months had significantly superior event-free survival rates compared with patients without an OR in groups A and B. The results of the present study have demonstrated most probably for the first time that an OR at 3 and 6 months in patients receiving either first-line GI and OI is clearly associated with greater response and event-free survival rates. Prospective randomized trials with larger numbers of patients and longer follow-up periods are needed to address the effect of EMR in patients receiving GI. Copyright © 2017 Elsevier Inc. All rights reserved.

Mapping of four distinct BCR-related loci to chromosome region 22q11: order of BCR loci relative to chronic myelogenous leukemia and acute lymphoblastic leukemia breakpoints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Croce, C.M.; Huebner, K.; Isobe, M.

1987-10-01

A probe derived from the 3' region of the BCR gene (breakpoint cluster region gene) detects four distinct loci in the human genome. One of the loci corresponds to the complete BCR gene, whereas the other contain a 3' segment of the gene. After HindIII cleavage of human DNA, these four loci are detected as 23-, 19-, 13-, and 9-kikobase-pair fragments, designated BCR4, BCR3, BCR2, and BCR1, respectively, with BCR1 deriving from the original complete BCR gene. All four BCR loci segregate 100% concordantly with human chromosome 22 in a rodent-human somatic cell hybrid panel and are located at chromosomemore » region 22q11.2 by chromosomal in situ hybridization. The BCR2 and BCR4 loci are amplified in leukemia cell line K562 cells, indicating that they fall within the amplification unit that includes immunoglobulin lambda light chain locus (IGL) and ABL locus on the K562 Philadelphia chromosome (Ph/sup 1/). Similarly, in mouse-human hybrids retaining a Ph/sup 1/ chromosome derived from an acute lymphoblastic leukemia-in the absence of the 9q/sup +/ and 22, only BCR2 and BCR4 loci are retained. Thus, the order of loci on chromosome 22 is centromere ..-->.. BCR2, BCR4, and IGL ..-->.. BCR1 ..-->.. BCR3 ..-->.. SIS, possibly eliminating BCR2 and BCR4 loci as candidate targets for juxtaposition to the ABL gene in the acute lymphoblastic leukemia Ph/sup 1/ chromosome.« less

Combined Targeting of BCL-2 and BCR-ABL Tyrosine Kinase Eradicates Chronic Myeloid Leukemia Stem Cells

PubMed Central

Mak, Po Yee; Mu, Hong; Zhou, Hongsheng; Mak, Duncan H.; Schober, Wendy; Leverson, Joel D.; Zhang, Bin; Bhatia, Ravi; Huang, Xuelin; Cortes, Jorge; Kantarjian, Hagop; Konopleva, Marina

2016-01-01

BCR-ABL tyrosine kinase inhibitors (TKIs) are effective against chronic myeloid leukemia (CML), but they rarely eliminate CML stem cells. Disease relapse is common upon therapy cessation, even in patients with complete molecular responses. Furthermore, once CML progresses to blast crisis (BC), treatment outcomes are dismal. We hypothesized that concomitant targeting of BCL-2 and BCR-ABL tyrosine kinase could overcome these limitations. We demonstrate increased BCL-2 expression at the protein level in bone marrow cells, particularly in Lin−Sca-1+cKit+ cells of inducible CML in mice as determined by CyTOF mass cytometry. Further, selective inhibition of BCL-2, aided by TKI-mediated MCL-1 and BCL-XL inhibition, markedly decreased leukemic Lin−Sca-1+cKit+ cell numbers and long-term stem cell frequency, and prolonged survival in a murine CML model. Additionally, this combination effectively eradicated CD34+CD38−, CD34+CD38+, and quiescent stem/progenitor CD34+ cells from BC CML patient samples. Our results suggest that BCL-2 is a key survival factor for CML stem/progenitor cells and that combined inhibition of BCL-2 and BCR-ABL tyrosine kinase has the potential to significantly improve depth of response and cure rates of chronic phase and BC CML. PMID:27605552

Characterization of leukemias with ETV6-ABL1 fusion.

PubMed

Zaliova, Marketa; Moorman, Anthony V; Cazzaniga, Giovanni; Stanulla, Martin; Harvey, Richard C; Roberts, Kathryn G; Heatley, Sue L; Loh, Mignon L; Konopleva, Marina; Chen, I-Ming; Zimmermannova, Olga; Schwab, Claire; Smith, Owen; Mozziconacci, Marie-Joelle; Chabannon, Christian; Kim, Myungshin; Frederik Falkenburg, J H; Norton, Alice; Marshall, Karen; Haas, Oskar A; Starkova, Julia; Stuchly, Jan; Hunger, Stephen P; White, Deborah; Mullighan, Charles G; Willman, Cheryl L; Stary, Jan; Trka, Jan; Zuna, Jan

2016-09-01

To characterize the incidence, clinical features and genetics of ETV6-ABL1 leukemias, representing targetable kinase-activating lesions, we analyzed 44 new and published cases of ETV6-ABL1-positive hematologic malignancies [22 cases of acute lymphoblastic leukemia (13 children, 9 adults) and 22 myeloid malignancies (18 myeloproliferative neoplasms, 4 acute myeloid leukemias)]. The presence of the ETV6-ABL1 fusion was ascertained by cytogenetics, fluorescence in-situ hybridization, reverse transcriptase-polymerase chain reaction and RNA sequencing. Genomic and gene expression profiling was performed by single nucleotide polymorphism and expression arrays. Systematic screening of more than 4,500 cases revealed that in acute lymphoblastic leukemia ETV6-ABL1 is rare in childhood (0.17% cases) and slightly more common in adults (0.38%). There is no systematic screening of myeloproliferative neoplasms; however, the number of ETV6-ABL1-positive cases and the relative incidence of acute lymphoblastic leukemia and myeloproliferative neoplasms suggest that in adulthood ETV6-ABL1 is more common in BCR-ABL1-negative chronic myeloid leukemia-like myeloproliferations than in acute lymphoblastic leukemia. The genomic profile of ETV6-ABL1 acute lymphoblastic leukemia resembled that of BCR-ABL1 and BCR-ABL1-like cases with 80% of patients having concurrent CDKN2A/B and IKZF1 deletions. In the gene expression profiling all the ETV6-ABL1-positive samples clustered in close vicinity to BCR-ABL1 cases. All but one of the cases of ETV6-ABL1 acute lymphoblastic leukemia were classified as BCR-ABL1-like by a standardized assay. Over 60% of patients died, irrespectively of the disease or age subgroup examined. In conclusion, ETV6-ABL1 fusion occurs in both lymphoid and myeloid leukemias; the genomic profile and clinical behavior resemble BCR-ABL1-positive malignancies, including the unfavorable prognosis, particularly of acute leukemias. The poor outcome suggests that treatment with tyrosine kinase inhibitors should be considered for patients with this fusion. Copyright© Ferrata Storti Foundation.

α-bisabolol Is an Effective Proapoptotic Agent against BCR-ABL+ Cells in Synergism with Imatinib and Nilotinib

PubMed Central

Bonifacio, Massimiliano; Rigo, Antonella; Guardalben, Emanuele; Bergamini, Christian; Cavalieri, Elisabetta; Fato, Romana; Pizzolo, Giovanni; Vinante, Fabrizio

2012-01-01

We showed that α-bisabolol is active against primary acute leukemia cells, including BCR-ABL+ acute lymphoblastic leukemias (ALL). Here we studied the activity of α-bisabolol against BCR-ABL+ cells using 3 cell lines (K562, LAMA-84, CML-T1) and 10 primary BCR-ABL+ ALL samples. We found that: (a) α-bisabolol was effective in reducing BCR-ABL+ cell viabilty at concentrations ranging from 53 to 73 µM; (b) α-bisabolol concentrations in BCR-ABL+ cellular compartments were 4- to 12-fold higher than in normal cells, thus indicating a preferential intake in neoplastic cells; (c) α-bisabolol displayed a slight to strong synergism with the Tyrosine Kinase Inhibitors (TKI) imatinib and nilotinib: the combination of α-bisabolol+imatinib allowed a dose reduction of each compound up to 7.2 and 9.4-fold respectively, while the combination of α-bisabolol+nilotinib up to 6.7 and 5-fold respectively; (d) α-bisabolol-induced apoptosis was associated with loss of plasma membrane integrity, irreversible opening of mitochondrial transition pore, disruption of mitochondrial potential, inhibition of oxygen consumption and increase of intracellular reactive oxygen species. These data indicate α-bisabolol as a candidate for treatment of BCR-ABL+ leukemias to overcome resistance to TKI alone and to target leukemic cells through BCR-ABL-independent pathways. PMID:23056396

Combined targeting of STAT3 and STAT5: a novel approach to overcome drug resistance in chronic myeloid leukemia.

PubMed

Gleixner, Karoline V; Schneeweiss, Mathias; Eisenwort, Gregor; Berger, Daniela; Herrmann, Harald; Blatt, Katharina; Greiner, Georg; Byrgazov, Konstantin; Hoermann, Gregor; Konopleva, Marina; Waliul, Islam; Cumaraswamy, Abbarna A; Gunning, Patrick T; Maeda, Hiroshi; Moriggl, Richard; Deininger, Michael; Lion, Thomas; Andreeff, Michael; Valent, Peter

2017-09-01

In chronic myeloid leukemia, resistance against BCR-ABL1 tyrosine kinase inhibitors can develop because of BCR-ABL1 mutations, activation of additional pro-oncogenic pathways, and stem cell resistance. Drug combinations covering a broad range of targets may overcome resistance. CDDO-Me (bardoxolone methyl) is a drug that inhibits the survival of leukemic cells by targeting different pro-survival molecules, including STAT3. We found that CDDO-Me inhibits proliferation and survival of tyrosine kinase inhibitor-resistant BCR-ABL1 + cell lines and primary leukemic cells, including cells harboring BCR-ABL1 T315I or T315I + compound mutations. Furthermore, CDDO-Me was found to block growth and survival of CD34 + /CD38 - leukemic stem cells (LSC). Moreover, CDDO-Me was found to produce synergistic growth-inhibitory effects when combined with BCR-ABL1 tyrosine kinase inhibitors. These drug-combinations were found to block multiple signaling cascades and molecules, including STAT3 and STAT5. Furthermore, combined targeting of STAT3 and STAT5 by shRNA and STAT5-targeting drugs also resulted in synergistic growth-inhibition, pointing to a new efficient concept of combinatorial STAT3 and STAT5 inhibition. However, CDDO-Me was also found to increase the expression of heme-oxygenase-1, a heat-shock-protein that triggers drug resistance and cell survival. We therefore combined CDDO-Me with the heme-oxygenase-1 inhibitor SMA-ZnPP, which also resulted in synergistic growth-inhibitory effects. Moreover, SMA-ZnPP was found to sensitize BCR-ABL1 + cells against the combination 'CDDO-Me+ tyrosine kinase inhibitor'. Together, combined targeting of STAT3, STAT5, and heme-oxygenase-1 overcomes resistance in BCR-ABL1 + cells, including stem cells and highly resistant sub-clones expressing BCR-ABL1 T315I or T315I-compound mutations. Whether such drug-combinations are effective in tyrosine kinase inhibitor-resistant patients with chronic myeloid leukemia remains to be elucidated. Copyright© 2017 Ferrata Storti Foundation.

Targeting the Allosteric Site of Oncoprotein BCR-ABL as an Alternative Strategy for Effective Target Protein Degradation.

PubMed

Shimokawa, Kenichiro; Shibata, Norihito; Sameshima, Tomoya; Miyamoto, Naoki; Ujikawa, Osamu; Nara, Hiroshi; Ohoka, Nobumichi; Hattori, Takayuki; Cho, Nobuo; Naito, Mikihiko

2017-10-12

Protein degradation technology based on hybrid small molecules is an emerging drug modality that has significant potential in drug discovery and as a unique method of post-translational protein knockdown in the field of chemical biology. Here, we report the first example of a novel and potent protein degradation inducer that binds to an allosteric site of the oncogenic BCR-ABL protein. BCR-ABL allosteric ligands were incorporated into the SNIPER (Specific and Nongenetic inhibitor of apoptosis protein [IAP]-dependent Protein Erasers) platform, and a series of in vitro biological assays of binding affinity, target protein modulation, signal transduction, and growth inhibition were carried out. One of the designed compounds, 6 (SNIPER(ABL)-062), showed desirable binding affinities against ABL1, cIAP1/2, and XIAP and consequently caused potent BCR-ABL degradation.

Myeloproliferative neoplasms with concurrent BCR-ABL1 translocation and JAK2 V617F mutation: a multi-institutional study from the bone marrow pathology group.

PubMed

Soderquist, Craig R; Ewalt, Mark D; Czuchlewski, David R; Geyer, Julia T; Rogers, Heesun J; Hsi, Eric D; Wang, Sa A; Bueso-Ramos, Carlos E; Orazi, Attilio; Arber, Daniel A; Hexner, Elizabeth O; Babushok, Daria V; Bagg, Adam

2018-05-01

Myeloproliferative neoplasms arise from hematopoietic stem cells with somatically altered tyrosine kinase signaling. Classification of myeloproliferative neoplasms is based on hematologic, histopathologic and molecular characteristics including the presence of the BCR-ABL1 and JAK2 V617F. Although thought to be mutually exclusive, a number of cases with co-occurring BCR-ABL1 and JAK2 V617F have been identified. To characterize the clinicopathologic features of myeloproliferative neoplasms with concomitant BCR-ABL1 and JAK2 V617F, and define the frequency of co-occurrence, we conducted a retrospective multi-institutional study. Cases were identified using a search of electronic databases over a decade at six major institutions. Of 1570 patients who were tested for both BCR-ABL1 and JAK2 V617F, six were positive for both. An additional five patients were identified via clinical records providing a total of 11 cases for detailed evaluation. For each case, clinical variables, hematologic and genetic data, and bone marrow histomorphologic features were analyzed. The sequence of identification of the genetic abnormalities varied: five patients were initially diagnosed with a JAK2 V617F+ myeloproliferative neoplasm, one patient initially had BCR-ABL1+ chronic myeloid leukemia, while both alterations were identified simultaneously in five patients. Classification of the BCR-ABL1-negative myeloproliferative neoplasms varied, and in some cases, features only became apparent following tyrosine kinase inhibitor therapy. Seven of the 11 patients showed myelofibrosis, in some cases before identification of the second genetic alteration. Our data, reflecting the largest reported study comprehensively detailing clinicopathologic features and response to therapy, show that the co-occurrence of BCR-ABL1 and JAK2 V617F is rare, with an estimated frequency of 0.4%, and most often reflects two distinct ('composite') myeloproliferative neoplasms. Although uncommon, it is important to be aware of this potentially confounding genetic combination, lest these features be misinterpreted to reflect resistance to therapy or disease progression, considerations that could lead to inappropriate management.

The impact of multiple low-level BCR-ABL1 mutations on response to ponatinib.

PubMed

Parker, Wendy T; Yeung, David T O; Yeoman, Alexandra L; Altamura, Haley K; Jamison, Bronte A; Field, Chani R; Hodgson, J Graeme; Lustgarten, Stephanie; Rivera, Victor M; Hughes, Timothy P; Branford, Susan

2016-04-14

The third-generation tyrosine kinase inhibitor (TKI) ponatinib shows activity against all common BCR-ABL1 single mutants, including the highly resistant BCR-ABL1-T315I mutant, improving outcome for patients with refractory chronic myeloid leukemia (CML). However, responses are variable, and causal baseline factors have not been well-studied. The type and number of low-level BCR-ABL1 mutations present after imatinib resistance has prognostic significance for subsequent treatment with nilotinib or dasatinib as second-line therapy. We therefore investigated the impact of low-level mutations detected by sensitive mass-spectrometry before ponatinib initiation (baseline) on treatment response in 363 TKI-resistant patients enrolled in the PONATINIB for Chronic Myeloid Leukemia Evaluation and Ph(+)Acute Lymphoblastic Leukemia trial, including 231 patients in chronic phase (CP-CML). Low-level mutations were detected in 53 patients (15%, including low-level T315I in 14 patients); most, however, did not undergo clonal expansion during ponatinib treatment and, moreover, no specific individual mutations were associated with inferior outcome. We demonstrate however, that the number of mutations detectable by mass spectrometry after TKI resistance is associated with response to ponatinib treatment and could be used to refine the therapeutic approach. Although CP-CML patients with T315I (63/231, 27%) had superior responses overall, those with multiple mutations detectable by mass spectrometry (20, 32%) had substantially inferior responses compared with those with T315I as the sole mutation detected (43, 68%). In contrast, for CP-CML patients without T315I, the inferior responses previously observed with nilotinib/dasatinib therapy for imatinib-resistant patients with multiple mutations were not seen with ponatinib treatment, suggesting that ponatinib may prove to be particularly advantageous for patients with multiple mutations detectable by mass spectrometry after TKI resistance. © 2016 by The American Society of Hematology.

An analysis of the kinetics of molecular response during the first trimester of treatment with nilotinib in newly diagnosed chronic myeloid leukemia patients in chronic phase.

PubMed

Steegmann, Juan Luis; Colomer, Dolors; Gómez-Casares, Maria-Teresa; García-Gutiérrez, Valentín; Ortí, Guillermo; Ramírez-Payer, Angel; Olavarria, Eduardo; Vall-Llovera, Ferrán; Giraldo, Pilar; Conde, Eulogio; Vallansot, Rolando; López-Lorenzo, Jose Luis; Palomera, Luis; Álvarez-Larrán, Alberto; Conesa, Venancio; Bautista, Guiomar; Casas, Laura; Giles, Frank; Hochhaus, Andreas; Casado-Montero, Luis Felipe

2017-10-01

This study was aimed to analyze the association of very early molecular response to nilotinib with the achievement of deep molecular response (MR4) at 18 months. We hypothesized that the BCR-ABL1 levels during the first 3 months of therapy, and the kinetics of their descent in this period, could be predictive of deep molecular response thereafter. This substudy of the ENEST1st trial included 60 patients with chronic myeloid leukemia in chronic phase treated with front-line nilotinib, and BCR-ABL1IS levels were measured using GUS as the control gene. The analysis included seven time points during the first trimester of treatment (baseline and fortnightly thereafter). The rates of MMR at 12 months, and of MR4 at 18 months (primary variable of the study), were 70 and 41%, respectively, similar to those obtained in the core study. BCR-ABL1IS ≤10% was achieved at 1, 1.5, 2 and 3 months in 50, 70, 83 and 93% of the patients, respectively. The observed shape of the BCR-ABL1IS descent was biphasic, with a faster slope during the first trimester and a median halving time (HT) of 11 days, the shortest reported in the literature. An HT ≤13 days was predictive of MMR at 12 months and MR4 at 18 months. The association of a shorter HT with response provides a rationale for exploring very early kinetics patterns in all patients treated with potent TKIs such as nilotinib.

Frequency of JAK2 V617F mutation in patients with Philadelphia positive Chronic Myeloid Leukemia in Pakistan.

PubMed

Tabassum, Najia; Saboor, Mohammed; Ghani, Rubina; Moinuddin, Moinuddin

2014-01-01

Co-existence of myeloproliferative disorders (MPD) and Janus associated kinase 2 mutation (JAK2 V617F) is a well-established fact. Only few case reports are available showing presence of JAK2 V617F mutation in chronic myeloid leukemia (CML). Purpose of this study was to determine the frequency of JAK2 V617F mutation in Philadelphia Chromosome positive (Ph (+)) CML patients in Pakistan. The study was conducted from August 2009 to July 2010 at Civil Hospital and Baqai Institute of Hematology (BIH) Karachi. Blood samples from 25 patients with CML were collected. Multiplex reverse transcription polymerase chain reaction (RT-PCR) was performed for Breakpoint Cluster Region - Abelson (BCR-ABL) rearrangement. Conventional PCR was performed for JAK2 V617F mutation on BCR-ABL positive samples. All 25 samples showed BCR-ABL rearrangement. Out of these 11 samples (44%) had JAK2 V617F mutation; the remaining 14 (56%) cases showed JAK2 617V wild type. It is concluded that the co-existence of Ph (+)CML and JAK2 V617F mutation is possible.

Dasatinib and low-intensity chemotherapy in elderly patients with Philadelphia chromosome–positive ALL

PubMed Central

Coudé, Marie Magdelaine; Gokbuget, Nicola; Gambacorti Passerini, Carlo; Hayette, Sandrine; Cayuela, Jean-Michel; Huguet, Françoise; Leguay, Thibaut; Chevallier, Patrice; Salanoubat, Celia; Bonmati, Caroline; Alexis, Magda; Hunault, Mathilde; Glaisner, Sylvie; Agape, Philippe; Berthou, Christian; Jourdan, Eric; Fernandes, José; Sutton, Laurent; Banos, Anne; Reman, Oumedaly; Lioure, Bruno; Thomas, Xavier; Ifrah, Norbert; Lafage-Pochitaloff, Marina; Bornand, Anne; Morisset, Laure; Robin, Valérie; Pfeifer, Heike; Delannoy, Andre; Ribera, Josep; Bassan, Renato; Delord, Marc; Hoelzer, Dieter; Dombret, Herve; Ottmann, Oliver G.

2016-01-01

Prognosis of Philadelphia-positive (Ph+) acute lymphoblastic leukemia (ALL) in the elderly has improved during the imatinib era. We investigated dasatinib, another potent tyrosine kinase inhibitor, in combination with low-intensity chemotherapy. Patients older than age 55 years were included in the European Working Group on Adult ALL (EWALL) study number 01 for Ph+ ALL (EWALL-PH-01 international study) and were treated with dasatinib 140 mg/day (100 mg/day over 70 years) with intrathecal chemotherapy, vincristine, and dexamethasone during induction. Patients in complete remission continued consolidation with dasatinib, sequentially with cytarabine, asparaginase, and methotrexate for 6 months. Maintenance therapy was dasatinib and vincristine/dexamethasone reinductions for 18 months followed by dasatinib until relapse or death. Seventy-one patients with a median age of 69 years were enrolled; 77% had a high comorbidity score. Complete remission rate was 96% and 65% of patients achieved a 3-log reduction in BCR-ABL1 transcript levels during consolidation. Only 7 patients underwent allogeneic hematopoietic stem cell transplantation. At 5 years, overall survival was 36% and up to 45% taking into account deaths unrelated to disease or treatment as competitors. Thirty-six patients relapsed, 24 were tested for mutation by Sanger sequencing, and 75% were T315I-positive. BCR-ABL1T315I was tested by allele-specific oligonucleotide reverse transcription–quantitative polymerase chain reaction in 43 patients and detection was associated with short-term relapses. Ten patients (23%) were positive before any therapy and 8 relapsed, all with this mutation. In conclusion, dasatinib combined with low-intensity chemotherapy was well-tolerated and gave long-term survival in 36% of elderly patients with Ph+ ALL. Monitoring of BCR-ABL1T315I from diagnosis identified patients with at high risk of early relapse and may help to personalize therapy. PMID:27121472

BAX/BCL-XL gene expression ratio inversely correlates with disease progression in chronic myeloid leukemia.

PubMed

Gonzalez, Mariana S; De Brasi, Carlos D; Bianchini, Michele; Gargallo, Patricia; Moiraghi, Beatriz; Bengió, Raquel; Larripa, Irene B

2010-10-15

BCR-ABL fusion gene is implicated in the pathogenesis of chronic myeloid leukemia (CML), encoding the oncoprotein p210(BCR-ABL) with anti-apoptotic activity. The inability to undergo apoptosis is an important mechanism of drug resistance and neoplastic evolution in CML. The gene transcript expression of mitochondrial apoptotic related genes BAX and BCL-XL was evaluated by quantitative Real Time PCR (qPCR) in vitro in K562 cells and in vivo in peripheral blood of 66 CML patients in different stages of the disease: 13 cases at diagnosis, 34 in chronic phase (CP), 10 in accelerated phase (AP) and 9 in blast crisis (BC). Our results in K562 cells showed that all treatments with different tyrosine kinase inhibitors (TKIs) induced a decreased expression of the antiapoptotic oncogene BCL-XL, whereas the proapoptotic gene BAX remains constant with minor modifications. A significantly lower BAX/BCL-XL expression ratio (mean±SEM) than a group of healthy individuals (4.8±0.59) were observed in CML patients at diagnosis (1.28 ± 0.16), in AP (1.14±0.20), in BC (1.16±0.30) and in 18% of cases of patients in CP (2.71±0.40). Most CP cases (82%) showed a significantly increased ratio (10.03±1.30), indicating that the treatment with TKIs efficiently inhibited the expression of BCL-XL by blocking BCR-ABL oncoprotein. The BAX/BCL-XL ratio showed a significant inverse correlation (Spearman P<0.0001) with BCR-ABL/ABL relative expression indicating that low BAX/BCL-XL was associated with disease progression. Accordingly, the follow up of a cohort of eight cases during 6months from diagnosis showed that while the BAX/BCL-XL ratio rapidly increased after treatment in seven cases with good evolution, it decreased in the single case that showed rapid evolution and short survival. Our data suggest that BAX/BCL-XL expression ratio may be a sensitive monitor of disease progression and an early predictor of TKI therapy responsiveness in CML patients. Copyright © 2010 Elsevier Inc. All rights reserved.

The proto-oncogene product p120CBL and the adaptor proteins CRKL and c-CRK link c-ABL, p190BCR/ABL and p210BCR/ABL to the phosphatidylinositol-3' kinase pathway.

PubMed

Sattler, M; Salgia, R; Okuda, K; Uemura, N; Durstin, M A; Pisick, E; Xu, G; Li, J L; Prasad, K V; Griffin, J D

1996-02-15

Chronic myelogenous leukemia (CML) and some acute lymphoblastic leukemias (ALL) are caused by the t(9;22) chromosome translocation, which produces the constitutively activated BCR/ABL tyrosine kinase. When introduced into factor dependent hematopoietic cell lines, BCR/ABL induces the tyrosine phosphorylation of many cellular proteins. One prominent BCR/ABL substrate is p120CBL, the cellular homolog of the v-Cbl oncoprotein. In an effort to understand the possible contribution of p120CBL to transformation by BCR/ABL, we looked for cellular proteins which associate with p120CBL in hematopoietic cell lines transformed by BCR/ABL. In addition to p210BCR/ABL and c-ABL, p120CBL coprecipitated with an 85 kDa phosphoprotein, which was identified as the p85 subunit of PI3K. Anti-p120CBL immunoprecipitates from BCR/ABL-transformed, but not from untransformed, cell lines contained PI3K lipid kinase activity. Interestingly, the adaptor proteins CRKL and c-CRK were also found in these complexes. In vitro binding studies indicated that the SH2 domains of CRKL and c-CRK bound directly to p120CBL, while the SH3 domains of c-CRK and CRKL bound to BCR/ABL and c-ABL. The N-terminal and the C-terminal SH2 and the SH3 domain of p85PI3K bound directly in vitro to p120CBL. The ABL-SH2, but not ABL-SH3, could also bind to p120CBL. These data suggest that BCR/ABL may induce the formation of multimeric complexes of signaling proteins which include p120CBL, PI3K, c-CRK or CRKL, c-ABL and BCR/ABL itself.

Targeting BCR-ABL-Independent TKI Resistance in Chronic Myeloid Leukemia by mTOR and Autophagy Inhibition.

PubMed

Mitchell, Rebecca; Hopcroft, Lisa E M; Baquero, Pablo; Allan, Elaine K; Hewit, Kay; James, Daniel; Hamilton, Graham; Mukhopadhyay, Arunima; O'Prey, Jim; Hair, Alan; Melo, Junia V; Chan, Edmond; Ryan, Kevin M; Maguer-Satta, Véronique; Druker, Brian J; Clark, Richard E; Mitra, Subir; Herzyk, Pawel; Nicolini, Franck E; Salomoni, Paolo; Shanks, Emma; Calabretta, Bruno; Holyoake, Tessa L; Helgason, G Vignir

2018-05-01

Imatinib and second-generation tyrosine kinase inhibitors (TKIs) nilotinib and dasatinib have statistically significantly improved the life expectancy of chronic myeloid leukemia (CML) patients; however, resistance to TKIs remains a major clinical challenge. Although ponatinib, a third-generation TKI, improves outcomes for patients with BCR-ABL-dependent mechanisms of resistance, including the T315I mutation, a proportion of patients may have or develop BCR-ABL-independent resistance and fail ponatinib treatment. By modeling ponatinib resistance and testing samples from these CML patients, it is hoped that an alternative drug target can be identified and inhibited with a novel compound. Two CML cell lines with acquired BCR-ABL-independent resistance were generated following culture in ponatinib. RNA sequencing and gene ontology (GO) enrichment were used to detect aberrant transcriptional response in ponatinib-resistant cells. A validated oncogene drug library was used to identify US Food and Drug Administration-approved drugs with activity against TKI-resistant cells. Validation was performed using bone marrow (BM)-derived cells from TKI-resistant patients (n = 4) and a human xenograft mouse model (n = 4-6 mice per group). All statistical tests were two-sided. We show that ponatinib-resistant CML cells can acquire BCR-ABL-independent resistance mediated through alternative activation of mTOR. Following transcriptomic analysis and drug screening, we highlight mTOR inhibition as an alternative therapeutic approach in TKI-resistant CML cells. Additionally, we show that catalytic mTOR inhibitors induce autophagy and demonstrate that genetic or pharmacological inhibition of autophagy sensitizes ponatinib-resistant CML cells to death induced by mTOR inhibition in vitro (% number of colonies of control[SD], NVP-BEZ235 vs NVP-BEZ235+HCQ: 45.0[17.9]% vs 24.0[8.4]%, P = .002) and in vivo (median survival of NVP-BEZ235- vs NVP-BEZ235+HCQ-treated mice: 38.5 days vs 47.0 days, P = .04). Combined mTOR and autophagy inhibition may provide an attractive approach to target BCR-ABL-independent mechanism of resistance.

Preclinical and clinical efficacy of XPO1/CRM1 inhibition by the karyopherin inhibitor KPT-330 in Ph+ leukemias

PubMed Central

Walker, Christopher J.; Oaks, Joshua J.; Santhanam, Ramasamy; Neviani, Paolo; Harb, Jason G.; Ferenchak, Gregory; Ellis, Justin J.; Landesman, Yosef; Eisfeld, Ann-Kathrin; Gabrail, Nash Y.; Smith, Carrie L.; Caligiuri, Michael A.; Hokland, Peter; Roy, Denis Claude; Reid, Alistair; Milojkovic, Dragana; Goldman, John M.; Apperley, Jane; Garzon, Ramiro; Marcucci, Guido; Shacham, Sharon; Kauffman, Michael G.

2013-01-01

As tyrosine kinase inhibitors (TKIs) fail to induce long-term response in blast crisis chronic myelogenous leukemia (CML-BC) and Philadelphia chromosome–positive (Ph+) acute lymphoblastic leukemia (ALL), novel therapies targeting leukemia-dysregulated pathways are necessary. Exportin-1 (XPO1), also known as chromosome maintenance protein 1, regulates cell growth and differentiation by controlling the nucleocytoplasmic trafficking of proteins and RNAs, some of which are aberrantly modulated in BCR-ABL1+ leukemias. Using CD34+ progenitors from CML, B-ALL, and healthy individuals, we found that XPO1 expression was markedly increased, mostly in a TKI-sensitive manner, in CML-BC and Ph+ B-ALL. Notably, XPO1 was also elevated in Ph− B-ALL. Moreover, the clinically relevant XPO1 inhibitor KPT-330 strongly triggered apoptosis and impaired the clonogenic potential of leukemic, but not normal, CD34+ progenitors, and increased survival of BCR-ABL1+ mice, 50% of which remained alive and, mostly, became BCR-ABL1 negative. Moreover, KPT-330 compassionate use in a patient with TKI-resistant CML undergoing disease progression significantly reduced white blood cell count, blast cells, splenomegaly, lactate dehydrogenase levels, and bone pain. Mechanistically, KPT-330 altered the subcellular localization of leukemia-regulated factors including RNA-binding heterogeneous nuclear ribonucleoprotein A1 and the oncogene SET, thereby inducing reactivation of protein phosphatase 2A tumor suppressor and inhibition of BCR-ABL1 in CML-BC cells. Because XPO1 is important for leukemic cell survival, KPT-330 may represent an alternative therapy for TKI-refractory Ph+ leukemias. PMID:23970380

Overexpression of Apg-2 increases cell proliferation and protects from oxidative damage in BaF3-BCR/ABL cells.

PubMed

Li, Chunli; Liu, Dingbin; Yuan, Ying; Huang, Shifeng; Shi, Meng; Tao, Kun; Feng, Wenli

2010-04-01

Apg-2, a mammalian heat-shock protein belonging to the heat-shock protein 110 (Hsp110) family, was previously found to be overexpressed in BaF3-BCR/ABL cells that were treated with hydrogen peroxide (H2O2) through our comparative proteomics study. The expression of Apg-2 in chronic myelogenous leukemia (CML) cells and its role have not been investigated, forming the basis for this study. BaF3-MIGR1 and BaF3-BCR/ABL cell lines stably overexpressing Apg-2 were established and exposed to 50 microM H2O2 for 10 min. Western blot analysis of Apg-2 expression confirmed that H2O2 treatment significantly up-regulated Apg-2 expression. Apg-2 overexpression elevated BaF3-BCR/ABL cell proportions in S and G2/M phase, increased cell proliferation and colony formation in vitro. Moreover, BaF3-MIGR1 and BaF3-BCR/ABL cells were exposed to 50 microM H2O2 in the absence or presence of Apg-2 overexpression and induction of H2AX phosphorylation, the reporters of DNA damage were assessed by Western blot and immunofluorescence. Results showed that exposure to H2O2 induced H2AX phosphorylation in BaF3-MIGR1 cells, but no increase was observed in BaF3-BCR/ABL cells. Together, the data indicate that Apg-2 is overexpressed and overexpression of Apg-2 in BaF3-BCR/ABL cells increases cell proliferation and protects cells from oxidative damage, which may play an important role in CML carcinogenesis and progression.

Identification of Bisindolylmaleimide IX as a potential agent to treat drug-resistant BCR-ABL positive leukemia

PubMed Central

Liu, Huijuan; Zang, Yi; Azam, Mohammad; Habib, Samy L.; Li, Jia; Ruan, Xinsen; Jia, Hao; Wang, Xueying; Li, Baojie

2016-01-01

Chronic myeloid leukemia (CML) treatment with BCR-ABL inhibitors is often hampered by development of drug resistance. In a screen for novel chemotherapeutic drug candidates with genotoxic activity, we identified a bisindolylmaleimide derivative, IX, as a small molecule compound with therapeutic potential against CML including drug-resistant CML. We show that Bisindolylmaleimide IX inhibits DNA topoisomerase, generates DNA breaks, activates the Atm-p53 and Atm-Chk2 pathways, and induces cell cycle arrest and cell death. Interestingly, Bisindolylmaleimide IX is highly effective in targeting cells positive for BCR-ABL. BCR-ABL positive cells display enhanced DNA damage and increased cell cycle arrest in response to Bisindolylmaleimide IX due to decreased expression of topoisomerases. Cells positive for BCR-ABL or drug-resistant T315I BCR-ABL also display increased cytotoxicity since Bisindolylmaleimide IX inhibits B-Raf and the downstream oncogene addiction pathway. Mouse cancer model experiments showed that Bisindolylmaleimide IX, at doses that show little side effect, was effective in treating leukemia-like disorders induced by BCR-ABL or T315I BCR-ABL, and prolonged the lifespan of these model mice. Thus, Bisindolylmaleimide IX presents a novel drug candidate to treat drug-resistant CML via activating BCR-ABL-dependent genotoxic stress response and inhibiting the oncogene addiction pathway activated by BCR-ABL. PMID:27564101

The use of Imatinib resistance mutation analysis to direct therapy in Philadelphia chromosome/BCR-ABL1 positive chronic myeloid leukaemia patients failing Imatinib treatment, in Patan Hospital, Nepal.

PubMed

Kayastha, Gyan K; Ranjitkar, Nora; Gurung, Radha; Kc, Raj Kumar; Karki, Sanjit; Shrestha, Roshan; Rajbhandari, Piyush; Thapa, Raj K; Poudyal, Buddhi; Acharya, Paras; Roberts, David J; Hayes, Bruce; Zimmerman, Mark; Basnyat, Buddha

2017-06-01

Philadelphia chromosome/BCR-ABL1 positive chronic myeloid leukaemia (CML) can be successfully treated with Glivec (Imatinib), which is available free of cost through the Glivec International Patient Assistance programme (GIPAP) to patients with proven CML without means to pay for the drug. We review the acquired mutations in the tyrosine kinase encoded by the BCR-ABL1 gene underlying Glivec failure or resistance in a cohort of 388 imatinib-treated CML patients (149 Female and 239 male) registered between February 2003 and June 2016 in Nepal. Forty-five patients (11 female 34 male) were studied; 18 different BCR-ABL1 mutations were seen in 33 patients. P-loop mutation, Kinase domain and A-loop mutations were seen in 9, 16 and 4 patients respectively. Other mutations were seen in five patients. A T315I mutation was the most common mutation, followed by F359V and M244V. Sixteen mutations showed intermediate activity to complete resistance to Glivec. Among the 45 patients evaluated for BCR-ABL1 mutations, 4 were lost to follow-up, 14 died and 27 are still alive. Among the surviving patients, 16 are receiving Nilotinib, 5 Dasatinib and 3 Ponatinib, while 3 patients were referred to India, one of who received allogenic bone marrow transplantation. Understanding the spectrum of further acquired mutations in BCR-ABL1 may help to choose more specific targeted tyrosine kinase inhibitors that can be provided by GIPAP. © 2017 John Wiley & Sons Ltd.

Tipifarnib in Treating Patients With Chronic Myeloid Leukemia, Chronic Myelomonocytic Leukemia, or Undifferentiated Myeloproliferative Disorders

ClinicalTrials.gov

2018-05-31

Accelerated Phase of Disease; Atypical Chronic Myeloid Leukemia, BCR-ABL1 Negative; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Chronic Myelomonocytic Leukemia; Chronic Phase of Disease; Myelodysplastic/Myeloproliferative Neoplasm, Unclassifiable; Recurrent Disease

Low expression of Abelson interactor-1 is linked to acquired drug resistance in Bcr-Abl induced leukemia

PubMed Central

Chorzalska, Anna; Salloum, Ibrahem; Shafqat, Hammad; Khan, Saad; Marjon, Philip; Treaba, Diana; Schorl, Christoph; Morgan, John; Bryke, Christine R.; Falanga, Vincent; Zhao, Thing C.; Reagan, John; Winer, Eric; Olszewski, Adam; Al-Homsi, Samer; Kouttab, Nicola; Dubielecka, Patrycja M.

2014-01-01

The basis for persistence of leukemic stem cells in the bone marrow microenvironment (BMME) remains poorly understood. We present evidence that signaling crosstalk between α4 integrin and Abelson interactor-1 (Abi-1) is involved in acquisition of an anchorage-dependent phenotype and drug resistance in Bcr-Abl positive leukemia cells. Comparison of Abi-1 (ABI-1) and α4 integrin (ITGA4) gene expression in relapsing Bcr-Abl positive CD34+ progenitor cells demonstrated a reduction in Abi-1 and an increase in α4 integrin mRNA in the absence of Bcr-Abl mutations. This inverse correlation between Abi-1 and α4 integrin expression, as well as linkage to elevated phospho-Akt and phospho-Erk signaling, was confirmed in imatinib mesylate (IM) resistant leukemic cells. These results indicate that the α4-Abi-1 signaling pathway may mediate acquisition of the drug resistant phenotype of leukemic cells. PMID:24699303

Overexpression of P-glycoprotein induces acquired resistance to imatinib in chronic myelogenous leukemia cells

PubMed Central

Peng, Xing-Xiang; Tiwari, Amit K.; Wu, Hsiang-Chun; Chen, Zhe-Sheng

2012-01-01

Imatinib, a breakpoint cluster region (BCR)-Abelson murine leukemia (ABL) tyrosine kinase inhibitor (TKI), has revolutionized the treatment of chronic myelogenous leukemia (CML). However, development of multidrug resistance (MDR) limits the use of imatinib. In the present study, we aimed to investigate the mechanisms of cellular resistance to imatinib in CML. Therefore, we established an imatinib-resistant human CML cell line (K562-imatinib) through a stepwise selection process. While characterizing the phenotype of these cells, we found that K562-imatinib cells were 124.6-fold more resistant to imatinib than parental K562 cells. In addition, these cells were cross-resistant to second- and third-generation BCR-ABL TKIs. Western blot analysis and reverse transcription-polymerase chain reaction(RT-PCR) demonstrated that P-glycoprotein (P-gp) and MDR1 mRNA levels were increased in K562-imatinib cells. In addition, accumulation of [14C]6-mercaptopurine (6-MP) was decreased, whereas the ATP-dependent efflux of [14C] 6-MP and [3H]methotrexate transport were increased in K562-imatinib cells. These data suggest that the overexpression of P-gp may play a crucial role in acquired resistance to imatinib in CML K562-imatinib cells. PMID:22098951

Self-enforcing Feedback Activation between BCL6 and Pre-B Cell Receptor Signaling Defines a Distinct Subtype of Acute Lymphoblastic Leukemia

PubMed Central

Geng, Huimin; Hurtz, Christian; Lenz, Kyle B.; Chen, Zhengshan; Baumjohann, Dirk; Thompson, Sarah; Goloviznina, Natalya; Chen, Wei-Yi; Huan, Jianya; LaTocha, Dorian; Ballabio, Erica; Xiao, Gang; Lee, Jae-Woong; Deucher, Anne; Qi, Zhongxia; Park, Eugene; Huang, Chuanxin; Nahar, Rahul; Kweon, Soo-Mi; Shojaee, Seyedmehdi; Chan, Lai N.; Yu, Jingwei; Kornblau, Steven M.; Bijl, Janetta J.; Ye, B. Hilda; Ansel, Mark; Paietta, Elisabeth; Melnick, Ari; Hunger, Stephen P.; Kurre, Peter; Tyner, Jeffrey W.; Loh, Mignon L.; Roeder, Robert G.; Druker, Brian J.; Burger, Jan. A.; Milne, Thomas A.; Chang, Bill H.; Müschen, Markus

2015-01-01

SUMMARY Studying 830 pre-B ALL cases from four clinical trials, we found that human ALL can be divided into two fundamentally distinct subtypes based on pre-BCR function. While absent in the majority of ALL cases, tonic pre-BCR signaling was found in 112 cases (13.5%). In these cases, tonic pre-BCR signaling induced activation of BCL6, which in turn increased pre-BCR signaling output at the transcriptional level. Interestingly, inhibition of pre-BCR-related tyrosine kinases reduced constitutive BCL6 expression and selectively killed patient-derived pre-BCR+ ALL cells. These findings identify a genetically and phenotypically distinct subset of human ALL that critically depends on tonic pre-BCR signaling. In vivo treatment studies suggested that pre-BCR tyrosine kinase inhibitors are useful for the treatment of patients with pre-BCR+ ALL. PMID:25759025

Activation of stress response gene SIRT1 by BCR-ABL promotes leukemogenesis

PubMed Central

Yuan, Hongfeng; Wang, Zhiqiang; Li, Ling; Zhang, Hao; Modi, Hardik; Horne, David

2012-01-01

The tyrosine kinase inhibitor imatinib is highly effective in the treatment of chronic myelogenous leukemia (CML), but primary and acquired resistance of CML cells to the drug offset its efficacy. Molecular mechanisms for resistance of CML to tyrosine kinase inhibitors are not fully understood. In the present study, we show that BCR-ABL activates the expression of the mammalian stress response gene SIRT1 in hematopoietic progenitor cells and that this involves STAT5 signaling. SIRT1 activation promotes CML cell survival and proliferation associated with deacetylation of multiple SIRT1 substrates, including FOXO1, p53, and Ku70. Imatinib-mediated inhibition of BCR-ABL kinase activity partially reduces SIRT1 expression and SIRT1 inhibition further sensitizes CML cells to imatinib-induced apoptosis. Knockout of SIRT1 suppresses BCR-ABL transformation of mouse BM cells and the development of a CML-like myeloproliferative disease, and treatment of mice with the SIRT1 inhibitor tenovin-6 deters disease progression. The combination of SIRT1 gene knockout and imatinib treatment further extends the survival of CML mice. Our results suggest that SIRT1 is a novel survival pathway activated by BCR-ABL expression in hematopoietic progenitor cells, which promotes oncogenic transformation and leukemogenesis. Our findings suggest further exploration of SIRT1 as a therapeutic target for CML treatment to overcome resistance. PMID:22207735

Final 5-Year Study Results of DASISION: The Dasatinib Versus Imatinib Study in Treatment-Naïve Chronic Myeloid Leukemia Patients Trial.

PubMed

Cortes, Jorge E; Saglio, Giuseppe; Kantarjian, Hagop M; Baccarani, Michele; Mayer, Jiří; Boqué, Concepción; Shah, Neil P; Chuah, Charles; Casanova, Luis; Bradley-Garelik, Brigid; Manos, George; Hochhaus, Andreas

2016-07-10

We report the 5-year analysis from the phase III Dasatinib Versus Imatinib Study in Treatment-Naïve Chronic Myeloid Leukemia Patients (DASISION) trial, evaluating long-term efficacy and safety outcomes of patients with chronic myeloid leukemia (CML) in chronic phase (CP) treated with dasatinib or imatinib. Patients with newly diagnosed CML-CP were randomly assigned to receive dasatinib 100 mg once daily (n = 259) or imatinib 400 mg once daily (n = 260). At the time of study closure, 61% and 63% of dasatinib- and imatinib-treated patients remained on initial therapy, respectively. Cumulative rates of major molecular response and molecular responses with a 4.0- or 4.5-log reduction in BCR-ABL1 transcripts from baseline by 5 years remained statistically significantly higher for dasatinib compared with imatinib. Rates for progression-free and overall survival at 5 years remained high and similar across treatment arms. In patients who achieved BCR-ABL1 ≤ 10% at 3 months (dasatinib, 84%; imatinib, 64%), improvements in progression-free and overall survival and lower rates of transformation to accelerated/blast phase were reported compared with patients with BCR-ABL1 greater than 10% at 3 months. Transformation to accelerated/blast phase occurred in 5% and 7% of patients in the dasatinib and imatinib arms, respectively. Fifteen dasatinib-treated and 19 imatinib-treated patients had BCR-ABL1 mutations identified at discontinuation. There were no new or unexpected adverse events identified in either treatment arm, and pleural effusion was the only drug-related, nonhematologic adverse event reported more frequently with dasatinib (28% v 0.8% with imatinib). First occurrences of pleural effusion were reported with dasatinib, with the highest incidence in year 1. Arterial ischemic events were uncommon in both treatment arms. These final results from the DASISION trial continue to support dasatinib 100 mg once daily as a safe and effective first-line therapy for the long-term treatment of CML-CP. © 2016 by American Society of Clinical Oncology.

BCR-ABL1-like acute lymphoblastic leukaemia: From bench to bedside.

PubMed

Boer, Judith M; den Boer, Monique L

2017-09-01

Acute lymphoblastic leukaemia (ALL) occurs in approximately 1:1500 children and is less frequently found in adults. The most common immunophenotype of ALL is the B cell lineage and within B cell precursor ALL, specific genetic aberrations define subtypes with distinct biological and clinical characteristics. With more advanced genetic analysis methods such as whole genome and transcriptome sequencing, novel genetic subtypes have recently been discovered. One novel class of genetic aberrations comprises tyrosine kinase-activating lesions, including translocations and rearrangements of tyrosine kinase and cytokine receptor genes. These newly discovered genetic aberrations are harder to detect by standard diagnostic methods such as karyotyping, fluorescent in situ hybridisation (FISH) or polymerase chain reaction (PCR) because they are diverse and often cryptic. These lesions involve one of several tyrosine kinase genes (among others, v-abl Abelson murine leukaemia viral oncogene homologue 1 (ABL1), v-abl Abelson murine leukaemia viral oncogene homologue 2 (ABL2), platelet-derived growth factor receptor beta polypeptide (PDGFRB)), each of which can be fused to up to 15 partner genes. Together, they compose 2-3% of B cell precursor ALL (BCP-ALL), which is similar in size to the well-known fusion gene BCR-ABL1 subtype. These so-called BCR-ABL1-like fusions are mutually exclusive with the sentinel translocations in BCP-ALL (BCR-ABL1, ETV6-RUNX1, TCF3-PBX1, and KMT2A (MLL) rearrangements) and have the promising prospect to be sensitive to tyrosine kinase inhibitors similar to BCR-ABL1. In this review, we discuss the types of tyrosine kinase-activating lesions discovered, and the preclinical and clinical evidence for the use of tyrosine kinase inhibitors in the treatment of this novel subtype of ALL. Copyright © 2017 Elsevier Ltd. All rights reserved.

Differential signaling through p190 and p210 BCR-ABL fusion proteins revealed by interactome and phosphoproteome analysis.

PubMed

Cutler, J A; Tahir, R; Sreenivasamurthy, S K; Mitchell, C; Renuse, S; Nirujogi, R S; Patil, A H; Heydarian, M; Wong, X; Wu, X; Huang, T-C; Kim, M-S; Reddy, K L; Pandey, A

2017-07-01

Two major types of leukemogenic BCR-ABL fusion proteins are p190 BCR-ABL and p210 BCR-ABL . Although the two fusion proteins are closely related, they can lead to different clinical outcomes. A thorough understanding of the signaling programs employed by these two fusion proteins is necessary to explain these clinical differences. We took an integrated approach by coupling protein-protein interaction analysis using biotinylation identification with global phosphorylation analysis to investigate the differences in signaling between these two fusion proteins. Our findings suggest that p190 BCR-ABL and p210 BCR-ABL differentially activate important signaling pathways, such as JAK-STAT, and engage with molecules that indicate interaction with different subcellular compartments. In the case of p210 BCR-ABL , we observed an increased engagement of molecules active proximal to the membrane and in the case of p190 BCR-ABL , an engagement of molecules of the cytoskeleton. These differences in signaling could underlie the distinct leukemogenic process induced by these two protein variants.

Growth of chronic myeloid leukemia cells is inhibited by infection with Ad-SH2-HA adenovirus that disrupts Grb2-Bcr-Abl complexes.

PubMed

Peng, Zhi; Luo, Hong-Wei; Yuan, Ying; Shi, Jing; Huang, Shi-Feng; Li, Chun-Li; Cao, Wei-Xi; Huang, Zong-Gan; Feng, Wen-Li

2011-05-01

The persistence of Bcr-Abl-positive cells in patients on imatinib therapy indicates that inhibition of the Bcr-Abl kinase activity alone might not be sufficient to eradicate the leukemia cells. Many downstream effectors of Bcr-Abl have been described, including activation of both the Grb2-SoS-Ras-MAPK and Grb2-Gab2-PI3K-Akt pathways. The Bcr-Abl-Grb2 interaction, which is mediated by the direct interaction of the Grb2 SH2 domain with the phospho-Bcr-Abl Y177, is required for activation of these signaling pathways. Therefore, disrupting their interaction represents a potential therapeutic strategy for inhibiting the oncogenic downstream signals of Bcr-Abl. Adenovirus Ad-SH2-HA expressing the Grb2 SH2 domain was constructed and applied in this study. As expected, Ad-SH2-HA efficiently infected CML cells and functioned by binding to the phospho-Bcr-Abl Y177 site, competitively disrupting the Grb2 SH2-phospho-Bcr-Abl Y177 complex. They induced potent anti-proliferation and apoptosis-inducing effects in CML cell lines. Moreover, the Ras, MAPK and Akt activities were significantly reduced in the Ad-SH2-HA treated cells. These were not observed with the point-mutated control adenovirus Ad-Sm-HA with abolished phospho-Bcr-Abl Y177 binding sites. These data indicate that, in addition to the direct targeting of Bcr-Abl, selective inhibition of its downstream signaling pathways may be a therapeutic option for CML, and the Ad-SH2-HA-mediated killing strategy could be explored as a promising anti-leukemia agent in CML.

A Virtual Screening Approach for the Identification of High Affinity Small Molecules Targeting BCR-ABL1 Inhibitors for the Treatment of Chronic Myeloid Leukemia.

PubMed

Sharda, Saphy; Sarmandal, Palash; Cherukommu, Shirisha; Dindhoria, Kiran; Yadav, Manisha; Bandaru, Srinivas; Sharma, Anudeep; Sakhi, Aditi; Vyas, Tanmay; Hussain, Tajamul; Nayarisseri, Anuraj; Singh, Sanjeev Kumar

2017-01-01

CML originates due to reciprocal translocation in Philadelphia chromosome leading to the formation of fusion product BCR-ABL which constitutively activates tyrosine kinase signaling pathways eventually leading to abnormal proliferation of granulocytic cells. As a therapeutic strategy, BCR-ABL inhibitors have been clinically approved which terminates its phosphorylation activity and retards cancer progression. However, a number of patients develop resistance to inhibitors which demand for the discovery of new inhibitors. Given the drawbacks of present inhibitors, by high throughput virtual screening approaches, present study pursues to identify high affinity compounds targeting BCR-ABL1 anticipated to have safer pharmacological profiles. Five established BCR-ABL inhibitors formed the query compounds for identification of structurally similar compounds by Tanimoto coefficient based linear fingerprint search with a threshold of 95% against PubChemdatabase. Assisted by MolDock algorithm all compounds were docked against BCR-ABL protein in order to retrieve high affinity compounds. The parents and similars were further tested for their ADMET propertiesand bioactivity. Rebastinib formed higher affinity inhibitor than rest of the four established compound investigated in the study. Interestingly, Rebastinib similar compound with Pubchem ID: 67254402 was also shown to have highest affinity than other similars including the similars of respective five parents. In terms of ADMET properties Pubchem ID: 67254402 had appreciable ADMET profile and bioactivity. However, Rebastinib still stood as the best inhibitor in terms of binding affinity and ADMET properties than Pubchem ID: 67254402. Nevertheless, owing to the similar pharmacological properties with Rebastinib, Pubchem ID: 67254402 can be expected to form potential BCR-ABL inhibitor. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Frequency of JAK2 V617F mutation in patients with Philadelphia positive Chronic Myeloid Leukemia in Pakistan

PubMed Central

Tabassum, Najia; Saboor, Mohammed; Ghani, Rubina; Moinuddin, Moinuddin

2014-01-01

Background and Objective: Co-existence of myeloproliferative disorders (MPD) and Janus associated kinase 2 mutation (JAK2 V617F) is a well-established fact. Only few case reports are available showing presence of JAK2 V617F mutation in chronic myeloid leukemia (CML). Purpose of this study was to determine the frequency of JAK2 V617F mutation in Philadelphia Chromosome positive (Ph +) CML patients in Pakistan. Methods: The study was conducted from August 2009 to July 2010 at Civil Hospital and Baqai Institute of Hematology (BIH) Karachi. Blood samples from 25 patients with CML were collected. Multiplex reverse transcription polymerase chain reaction (RT-PCR) was performed for Breakpoint Cluster Region – Abelson (BCR-ABL) rearrangement. Conventional PCR was performed for JAK2 V617F mutation on BCR-ABL positive samples. Results: All 25 samples showed BCR-ABL rearrangement. Out of these 11 samples (44%) had JAK2 V617F mutation; the remaining 14 (56%) cases showed JAK2 617V wild type. Conclusion: It is concluded that the co-existence of Ph +CML and JAK2 V617F mutation is possible. PMID:24639858

Disrupting BCR-ABL in combination with secondary leukemia-specific pathways in CML cells leads to enhanced apoptosis and decreased proliferation.

PubMed

Woessner, David W; Lim, Carol S

2013-01-07

Chronic myeloid leukemia (CML) is a myeloproliferative disorder caused by expression of the fusion gene BCR-ABL following a chromosomal translocation in the hematopoietic stem cell. Therapeutic management of CML uses tyrosine kinase inhibitors (TKIs), which block ABL-signaling and effectively kill peripheral cells with BCR-ABL. However, TKIs are not curative, and chronic use is required in order to treat CML. The primary failure for TKIs is through the development of a resistant population due to mutations in the TKI binding regions. This led us to develop the mutant coiled-coil, CC(mut2), an alternative method for BCR-ABL signaling inhibition by targeting the N-terminal oligomerization domain of BCR, necessary for ABL activation. In this article, we explore additional pathways that are important for leukemic stem cell survival in K562 cells. Using a candidate-based approach, we test the combination of CC(mut2) and inhibitors of unique secondary pathways in leukemic cells. Transformative potential was reduced following silencing of the leukemic stem cell factor Alox5 by RNA interference. Furthermore, blockade of the oncogenic protein MUC-1 by the novel peptide GO-201 yielded reductions in proliferation and increased cell death. Finally, we found that inhibiting macroautophagy using chloroquine in addition to blocking BCR-ABL signaling with the CC(mut2) was most effective in limiting cell survival and proliferation. This study has elucidated possible combination therapies for CML using novel blockade of BCR-ABL and secondary leukemia-specific pathways.

AP24534, a Pan-BCR-ABL Inhibitor for Chronic Myeloid Leukemia, Potently Inhibits the T315I Mutant and Overcomes Mutation-Based Resistance

DOE Office of Scientific and Technical Information (OSTI.GOV)

O’Hare, Thomas; Shakespeare, William C.; Zhu, Xiaotian

2010-09-07

Inhibition of BCR-ABL by imatinib induces durable responses in many patients with chronic myeloid leukemia (CML), but resistance attributable to kinase domain mutations can lead to relapse and a switch to second-line therapy with nilotinib or dasatinib. Despite three approved therapeutic options, the cross-resistant BCR-ABL{sup T315I} mutation and compound mutants selected on sequential inhibitor therapy remain major clinical challenges. We report design and preclinical evaluation of AP24534, a potent, orally available multitargeted kinase inhibitor active against T315I and other BCR-ABL mutants. AP24534 inhibited all tested BCR-ABL mutants in cellular and biochemical assays, suppressed BCR-ABL{sup T315I}-driven tumor growth in mice, andmore » completely abrogated resistance in cell-based mutagenesis screens. Our work supports clinical evaluation of AP24534 as a pan-BCR-ABL inhibitor for treatment of CML.« less

Donor Umbilical Cord Blood Transplant in Treating Patients With Hematologic Cancer

ClinicalTrials.gov

2018-01-17

Acute Lymphoblastic Leukemia; Acute Myeloid Leukemia; Aggressive Non-Hodgkin Lymphoma; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Chronic Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Indolent Non-Hodgkin Lymphoma; Lymphoma; Mixed Phenotype Acute Leukemia; Myelodysplastic Syndrome; Myeloproliferative Neoplasm; Recurrent Chronic Lymphocytic Leukemia; Recurrent Follicular Lymphoma; Recurrent Lymphoplasmacytic Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Plasma Cell Myeloma; Recurrent Small Lymphocytic Lymphoma; Recurrent T-Cell Non-Hodgkin Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Refractory Follicular Lymphoma; Refractory Hodgkin Lymphoma; Refractory Lymphoplasmacytic Lymphoma; Refractory Mantle Cell Lymphoma; Refractory Small Lymphocytic Lymphoma; T-Cell Non-Hodgkin Lymphoma

Survival implications of molecular heterogeneity in variant Philadelphia-positive chronic myeloid leukaemia.

PubMed

Reid, Alistair G; Huntly, Brian J P; Grace, Colin; Green, Anthony R; Nacheva, Elisabeth P

2003-05-01

The BCR-ABL fusion in chronic myeloid leukaemia (CML) is generated by the Philadelphia (Ph) translocation t(9;22) or, in 10% of patients, variants thereof (vPh). Deletion encompassing the reciprocal product (ABL-BCR) from the derivative chromosome 9 [der(9)] occurs in 15% of all patients, but with greater frequency in vPh patients. Reports of physical separation of ABL-BCR in non-deleted patients, as well as evolution from classical to variant Ph, introduce further heterogeneity to the vPh subgroup and raise the possibility that such translocations may herald disease progression. Survival analyses, however, have thus far yielded contradictory results. We assessed the frequency of der(9) deletions, ABL-BCR abrogation, cytogenetic evolution and cryptic rearrangement in a large cohort of 54 patients with vPh CML. Deletions encompassing ABL-BCR were detected in 37% of patients, consistent with a model in which a greater number of chromosome breaks increases the risk of genomic loss. The components of ABL-BCR were physically separated in a further 52% of patients while fused in the remaining 11%. Evolution from classical to vPh was demonstrated in three patients. The difference in survival, as indicated by Kaplan-Meier analysis, was marked between classical and vPh patients (105 vs 60 months respectively; P = 0.0002). Importantly, this difference disappeared when patients with deletions were removed from the analysis. Our study showed that, despite the existence of several levels of genomic heterogeneity in variant Ph-positive CML, der(9) deletion status is the key prognostic factor.

Selective Depletion of CD45RA+ T Cells From Allogeneic Peripheral Blood Stem Cell Grafts in Preventing GVHD in Children

ClinicalTrials.gov

2018-04-23

Accelerated Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Acute Biphenotypic Leukemia; Acute Leukemia of Ambiguous Lineage; Acute Undifferentiated Leukemia; Adult Acute Lymphoblastic Leukemia in Remission; Adult Acute Myeloid Leukemia in Remission; Blast Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Childhood Acute Lymphoblastic Leukemia in Remission; Childhood Acute Myeloid Leukemia in Remission; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Myelodysplastic Syndrome With Excess Blasts-1; Myelodysplastic Syndrome With Excess Blasts-2; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Refractory Adult Acute Lymphoblastic Leukemia; Refractory Childhood Acute Lymphoblastic Leukemia

Imatinib Mesylate and Combination Chemotherapy in Treating Patients With Newly Diagnosed Philadelphia Chromosome Positive Acute Lymphoblastic Leukemia

ClinicalTrials.gov

2018-05-02

Acute Lymphoblastic Leukemia; B Acute Lymphoblastic Leukemia With t(9;22)(q34.1;q11.2); BCR-ABL1; BCR-ABL1 Fusion Protein Expression; Minimal Residual Disease; Philadelphia Chromosome Positive; T Acute Lymphoblastic Leukemia; Untreated Adult Acute Lymphoblastic Leukemia; Untreated Childhood Acute Lymphoblastic Leukemia

Dasatinib and Combination Chemotherapy in Treating Young Patients With Newly Diagnosed Acute Lymphoblastic Leukemia

ClinicalTrials.gov

2016-09-08

Adult B Acute Lymphoblastic Leukemia With t(9;22)(q34;q11.2); BCR-ABL1; Childhood B Acute Lymphoblastic Leukemia With t(9;22)(q34;q11.2); BCR-ABL1; Untreated Adult Acute Lymphoblastic Leukemia; Untreated Childhood Acute Lymphoblastic Leukemia

Bcr/Abl interferes with the Fanconi anemia/BRCA pathway: implications in the chromosomal instability of chronic myeloid leukemia cells.

PubMed

Valeri, Antonio; Alonso-Ferrero, Maria Eugenia; Río, Paula; Pujol, María Roser; Casado, José A; Pérez, Laura; Jacome, Ariana; Agirre, Xabier; Calasanz, Maria José; Hanenberg, Helmut; Surrallés, Jordi; Prosper, Felipe; Albella, Beatriz; Bueren, Juan A

2010-12-28

Chronic myeloid leukemia (CML) is a malignant clonal disorder of the hematopoietic system caused by the expression of the BCR/ABL fusion oncogene. Although it is well known that CML cells are genetically unstable, the mechanisms accounting for this genomic instability are still poorly understood. Because the Fanconi anemia (FA) pathway is believed to control several mechanisms of DNA repair, we investigated whether this pathway was disrupted in CML cells. Our data show that CML cells have a defective capacity to generate FANCD2 nuclear foci, either in dividing cells or after DNA damage. Similarly, human cord blood CD34(+) cells transduced with BCR/ABL retroviral vectors showed impaired FANCD2 foci formation, whereas FANCD2 monoubiquitination in these cells was unaffected. Soon after the transduction of CD34(+) cells with BCR/ABL retroviral vectors a high proportion of cells with supernumerary centrosomes was observed. Similarly, BCR/ABL induced a high proportion of chromosomal abnormalities, while mediated a cell survival advantage after exposure to DNA cross-linking agents. Significantly, both the impaired formation of FANCD2 nuclear foci, and also the predisposition of BCR/ABL cells to develop centrosomal and chromosomal aberrations were reverted by the ectopic expression of BRCA1. Taken together, our data show for the first time a disruption of the FA/BRCA pathway in BCR/ABL cells, suggesting that this defective pathway should play an important role in the genomic instability of CML by the co-occurrence of centrosomal amplification and DNA repair deficiencies.

PAX5 tyrosine phosphorylation by SYK co-operatively functions with its serine phosphorylation to cancel the PAX5-dependent repression of BLIMP1: A mechanism for antigen-triggered plasma cell differentiation.

PubMed

Inagaki, Yuichiro; Hayakawa, Fumihiko; Hirano, Daiki; Kojima, Yuki; Morishita, Takanobu; Yasuda, Takahiko; Naoe, Tomoki; Kiyoi, Hitoshi

2016-06-24

Plasma cell differentiation is initiated by antigen stimulation of the B cell receptor (BCR) and is regulated by BLIMP1. Prior to the stimulation of BCR, BLIMP1 is suppressed by PAX5, which is a key transcriptional repressor that maintains B cell identity. The upregulation of BLIMP1 and subsequent suppression of PAX5 by BLIMP1 are observed after the BCR stimulation. These events are considered to trigger plasma cell differentiation; however, the mechanisms responsible currently remain unclear. We herein demonstrated that the BCR signaling component, SYK, caused PAX5 tyrosine phosphorylation in vitro and in cells. Transcriptional repression on the BLIMP1 promoter by PAX5 was attenuated by this phosphorylation. The BCR stimulation induced the phosphorylation of SYK, tyrosine phosphorylation of PAX5, and up-regulation of BLIMP1 mRNA expression in B cells. The tyrosine phosphorylation of PAX5 co-operatively functioned with PAX5 serine phosphorylation by ERK1/2, which was our previous findings, to cancel the PAX5-dependent repression of BLIMP1. This co-operation may be a trigger for plasma cell differentiation. These results imply that PAX5 phosphorylation by a BCR signal is the initial event in plasma cell differentiation. Copyright © 2016 Elsevier Inc. All rights reserved.

FTY720, a new alternative for treating blast crisis chronic myelogenous leukemia and Philadelphia chromosome–positive acute lymphocytic leukemia

PubMed Central

Neviani, Paolo; Santhanam, Ramasamy; Oaks, Joshua J.; Eiring, Anna M.; Notari, Mario; Blaser, Bradley W.; Liu, Shujun; Trotta, Rossana; Muthusamy, Natarajan; Gambacorti-Passerini, Carlo; Druker, Brian J.; Cortes, Jorge; Marcucci, Guido; Chen, Ching-Shih; Verrills, Nicole M.; Roy, Denis C.; Caligiuri, Michael A.; Bloomfield, Clara D.; Byrd, John C.; Perrotti, Danilo

2007-01-01

Blast crisis chronic myelogenous leukemia (CML-BC) and Philadelphia chromosome–positive (Ph1-positive) acute lymphocytic leukemia (ALL) are 2 fatal BCR/ABL-driven leukemias against which Abl kinase inhibitors fail to induce a long-term response. We recently reported that functional loss of protein phosphatase 2A (PP2A) activity is important for CML blastic transformation. We assessed the therapeutic potential of the PP2A activator FTY720 (2-amino-2-[2-(4-octylphenyl)ethyl]-1,3-propanediol hydrochloride), an immunomodulator in Phase III trials for patients with multiple sclerosis or undergoing organ transplantation, in CML-BC and Ph1 ALL patient cells and in in vitro and in vivo models of these BCR/ABL+ leukemias. Our data indicate that FTY720 induces apoptosis and impairs clonogenicity of imatinib/dasatinib-sensitive and -resistant p210/p190BCR/ABL myeloid and lymphoid cell lines and CML-BCCD34+ and Ph1 ALLCD34+/CD19+ progenitors but not of normal CD34+ and CD34+/CD19+ bone marrow cells. Furthermore, pharmacologic doses of FTY720 remarkably suppress in vivo p210/p190BCR/ABL-driven [including p210/p190BCR/ABL (T315I)] leukemogenesis without exerting any toxicity. Altogether, these results highlight the therapeutic relevance of rescuing PP2A tumor suppressor activity in Ph1 leukemias and strongly support the introduction of the PP2A activator FTY720 in the treatment of CML-BC and Ph1 ALL patients. PMID:17717597

Discovery of 3-[2-(imidazo[1,2-b]pyridazin-3-yl)ethynyl]-4-methyl-N-{4-[(4-methylpiperazin-1-yl)methyl]-3-(trifluoromethyl)phenyl}benzamide (AP24534), a potent, orally active pan-inhibitor of breakpoint cluster region-abelson (BCR-ABL) kinase including the T315I gatekeeper mutant.

PubMed

Huang, Wei-Sheng; Metcalf, Chester A; Sundaramoorthi, Raji; Wang, Yihan; Zou, Dong; Thomas, R Mathew; Zhu, Xiaotian; Cai, Lisi; Wen, David; Liu, Shuangying; Romero, Jan; Qi, Jiwei; Chen, Ingrid; Banda, Geetha; Lentini, Scott P; Das, Sasmita; Xu, Qihong; Keats, Jeff; Wang, Frank; Wardwell, Scott; Ning, Yaoyu; Snodgrass, Joseph T; Broudy, Marc I; Russian, Karin; Zhou, Tianjun; Commodore, Lois; Narasimhan, Narayana I; Mohemmad, Qurish K; Iuliucci, John; Rivera, Victor M; Dalgarno, David C; Sawyer, Tomi K; Clackson, Tim; Shakespeare, William C

2010-06-24

In the treatment of chronic myeloid leukemia (CML) with BCR-ABL kinase inhibitors, the T315I gatekeeper mutant has emerged as resistant to all currently approved agents. This report describes the structure-guided design of a novel series of potent pan-inhibitors of BCR-ABL, including the T315I mutation. A key structural feature is the carbon-carbon triple bond linker which skirts the increased bulk of Ile315 side chain. Extensive SAR studies led to the discovery of development candidate 20g (AP24534), which inhibited the kinase activity of both native BCR-ABL and the T315I mutant with low nM IC(50)s, and potently inhibited proliferation of corresponding Ba/F3-derived cell lines. Daily oral administration of 20g significantly prolonged survival of mice injected intravenously with BCR-ABL(T315I) expressing Ba/F3 cells. These data, coupled with a favorable ADME profile, support the potential of 20g to be an effective treatment for CML, including patients refractory to all currently approved therapies.

Dual Drug Targeting of Mutant Bcr-Abl Induces Inactive Conformation: New Strategy for the Treatment of Chronic Myeloid Leukemia and Overcoming Monotherapy Resistance.

PubMed

El Rashedy, Ahmed A; Olotu, Fisayo A; Soliman, Mahmoud E S

2018-03-01

Bcr-Abl is an oncogenic fusion protein which expression enhances tumorigenesis, and has been highly associated with chronic myeloid leukemia (CML). Acquired drug resistance in mutant Bcr-Abl has enhanced pathogenesis with the use of single therapy agents such as nilotinib. Moreover, allosteric targeting has been identified to consequentially inhibit Bcr-Abl activity, which led to the recent development of ABL-001 (asciminib) that selectively binds the myristoyl pocket. Experimental studies have revealed that the combination of nilotinib and ABL-001 induced a 'bent' conformation in the C-terminal helix of Bcr-Abl; a benchmark of inhibition, thereby exhibiting a greater potency in the treatment of CML, surmounting the setbacks of drug resistance, disease regression and relapse. Therefore, we report the first account of the dynamics and conformational analysis of oncogenic T334I Bcr-Abl by dual targeting. Our findings revealed that unlike in the Bcr-Abl-Nilotinib complex, dual targeting by both inhibitors induced the bent conformation in the C-terminal helix that varied with time. This was coupled with significant alteration in Bcr-Abl stability, flexibility, and compactness and an overall structural re-orientation inwards towards the hydrophobic core, which reduced the solvent-exposed residues indicative of protein folding. This study will facilitate allosteric targeting and the design of more potent allosteric inhibitors for resistive target proteins in cancer. © 2018 Wiley-VHCA AG, Zurich, Switzerland.

BCR-ABL1 promotes leukemia by converting p27 into a cytoplasmic oncoprotein

PubMed Central

Mackenzie, Ryan J.; Besson, Arnaud; Jeng, Sophia; Carey, Alyssa; LaTocha, Dorian H.; Fleischman, Angela G.; Duquesnes, Nicolas; Eide, Christopher A.; Vasudevan, Kavin B.; Loriaux, Marc M.; Firpo, Eduardo; Cortes, Jorge E.; McWeeney, Shannon; O’Hare, Thomas; Roberts, James M.; Druker, Brian J.; Deininger, Michael W.

2014-01-01

Recent studies have revealed that p27, a nuclear cyclin-dependent kinase (Cdk) inhibitor and tumor suppressor, can acquire oncogenic activities upon mislocalization to the cytoplasm. To understand how these antagonistic activities influence oncogenesis, we dissected the nuclear and cytoplasmic functions of p27 in chronic myeloid leukemia (CML), a well-characterized malignancy caused by the BCR-ABL1 tyrosine kinase. p27 is predominantly cytoplasmic in CML and nuclear in normal cells. BCR-ABL1 regulates nuclear and cytoplasmic p27 abundance by kinase-dependent and -independent mechanisms, respectively. p27 knockdown in CML cell lines with predominantly cytoplasmic p27 induces apoptosis, consistent with a leukemogenic role of cytoplasmic p27. Accordingly, a p27 mutant (p27CK−) devoid of Cdk inhibitory nuclear functions enhances leukemogenesis in a murine CML model compared with complete absence of p27. In contrast, p27 mutations that enhance its stability (p27T187A) or nuclear retention (p27S10A) attenuate leukemogenesis over wild-type p27, validating the tumor-suppressor function of nuclear p27 in CML. We conclude that BCR-ABL1 kinase-dependent and -independent mechanisms convert p27 from a nuclear tumor suppressor to a cytoplasmic oncogene. These findings suggest that cytoplasmic mislocalization of p27 despite BCR-ABL1 inhibition by tyrosine kinase inhibitors may contribute to drug resistance, and effective therapeutic strategies to stabilize nuclear p27 must also prevent cytoplasmic mislocalization. PMID:25293778

Long-term remission in BCR/ABL-positive AML-M6 patient treated with Imatinib Mesylate.

PubMed

Pompetti, Franca; Spadano, Antonio; Sau, Antonella; Mennucci, Antonio; Russo, Rosa; Catinella, Virginia; Franchi, Paolo Guanciali; Calabrese, Giuseppe; Palka, Giandomenico; Fioritoni, Giuseppe; Iacone, Antonio

2007-04-01

BCR/ABL-positive acute myeloid leukemia (AML) is a rare disease, characterized by a poor prognosis, with resistance to induction chemotherapy and frequent relapses in responsive patients. Here we report a case of BCR/ABL-positive AML-M6 who, after relapse, was treated with Imatinib Mesylate (600 mg/die) and within 4 months achieved a cytogenetic and molecular complete response. After more than 4 years of continuous Imatinib therapy, nested RT-PCR for BCR/ABL is persistently negative. The case reported shows that the response obtained with Imatinib Mesylate in BCR/ABL-positive AML may be long lasting, offering a chance of successful treatment for this poor prognosis group of patients.

Targeting the SH2-Kinase Interface in Bcr-Abl Inhibits Leukemogenesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grebien, Florian; Hantschel, Oliver; Wojcik, John

2012-10-25

Chronic myelogenous leukemia (CML) is caused by the constitutively active tyrosine kinase Bcr-Abl and treated with the tyrosine kinase inhibitor (TKI) imatinib. However, emerging TKI resistance prevents complete cure. Therefore, alternative strategies targeting regulatory modules of Bcr-Abl in addition to the kinase active site are strongly desirable. Here, we show that an intramolecular interaction between the SH2 and kinase domains in Bcr-Abl is both necessary and sufficient for high catalytic activity of the enzyme. Disruption of this interface led to inhibition of downstream events critical for CML signaling and, importantly, completely abolished leukemia formation in mice. Furthermore, disruption of themore » SH2-kinase interface increased sensitivity of imatinib-resistant Bcr-Abl mutants to TKI inhibition. An engineered Abl SH2-binding fibronectin type III monobody inhibited Bcr-Abl kinase activity both in vitro and in primary CML cells, where it induced apoptosis. This work validates the SH2-kinase interface as an allosteric target for therapeutic intervention.« less

Targeting the SH2-kinase interface in Bcr-Abl inhibits leukemogenesis.

PubMed

Grebien, Florian; Hantschel, Oliver; Wojcik, John; Kaupe, Ines; Kovacic, Boris; Wyrzucki, Arkadiusz M; Gish, Gerald D; Cerny-Reiterer, Sabine; Koide, Akiko; Beug, Hartmut; Pawson, Tony; Valent, Peter; Koide, Shohei; Superti-Furga, Giulio

2011-10-14

Chronic myelogenous leukemia (CML) is caused by the constitutively active tyrosine kinase Bcr-Abl and treated with the tyrosine kinase inhibitor (TKI) imatinib. However, emerging TKI resistance prevents complete cure. Therefore, alternative strategies targeting regulatory modules of Bcr-Abl in addition to the kinase active site are strongly desirable. Here, we show that an intramolecular interaction between the SH2 and kinase domains in Bcr-Abl is both necessary and sufficient for high catalytic activity of the enzyme. Disruption of this interface led to inhibition of downstream events critical for CML signaling and, importantly, completely abolished leukemia formation in mice. Furthermore, disruption of the SH2-kinase interface increased sensitivity of imatinib-resistant Bcr-Abl mutants to TKI inhibition. An engineered Abl SH2-binding fibronectin type III monobody inhibited Bcr-Abl kinase activity both in vitro and in primary CML cells, where it induced apoptosis. This work validates the SH2-kinase interface as an allosteric target for therapeutic intervention. Copyright © 2011 Elsevier Inc. All rights reserved.

Targeting the SH2-Kinase Interface in Bcr-Abl Inhibits Leukemogenesis

PubMed Central

Grebien, Florian; Hantschel, Oliver; Wojcik, John; Kaupe, Ines; Kovacic, Boris; Wyrzucki, Arkadiusz M.; Gish, Gerald D.; Cerny-Reiterer, Sabine; Koide, Akiko; Beug, Hartmut; Pawson, Tony; Valent, Peter; Koide, Shohei; Superti-Furga, Giulio

2011-01-01

Summary Chronic myelogenous leukemia (CML) is caused by the constitutively active tyrosine kinase Bcr-Abl and treated with the tyrosine kinase inhibitor (TKI) imatinib. However, emerging TKI resistance prevents complete cure. Therefore, alternative strategies targeting regulatory modules of Bcr-Abl in addition to the kinase active site are strongly desirable. Here, we show that an intramolecular interaction between the SH2 and kinase domains in Bcr-Abl is both necessary and sufficient for high catalytic activity of the enzyme. Disruption of this interface led to inhibition of downstream events critical for CML signaling and, importantly, completely abolished leukemia formation in mice. Furthermore, disruption of the SH2-kinase interface increased sensitivity of imatinib-resistant Bcr-Abl mutants to TKI inhibition. An engineered Abl SH2-binding fibronectin type III monobody inhibited Bcr-Abl kinase activity both in vitro and in primary CML cells, where it induced apoptosis. This work validates the SH2-kinase interface as an allosteric target for therapeutic intervention. PaperFlick PMID:22000011

A BCR-ABL Kinase Activity-Independent Signaling Pathway in Chronic Myelogenous Leukemia

DTIC Science & Technology

2008-02-01

myeloproliferative disease in mice receiving P210 bcr/abl-transduced bone marrow. Blood. 1998;92:3780-3792. 17. Zhang X, Ren R. Bcr-Abl efficiently induces a... myeloproliferative disease and production of excess interleukin-3 and granulocyte-macrophage colony-stimulating factor in mice: a novel model for chronic...Xu L, et al. Efficient and rapid induction of a chronic myelogenous leukemia-like myeloproliferative disease in mice receiving P210 bcr/abl-transduced

Targeting of the N-terminal coiled coil oligomerization interface of BCR interferes with the transformation potential of BCR-ABL and increases sensitivity to STI571.

PubMed

Beissert, Tim; Puccetti, Elena; Bianchini, Andrea; Güller, Saskia; Boehrer, Simone; Hoelzer, Dieter; Ottmann, Oliver Gerhard; Nervi, Clara; Ruthardt, Martin

2003-10-15

Translocations involving the abl locus on chromosome 9 fuses the tyrosine kinase c-ABL to proteins harboring oligomerization interfaces such as BCR or TEL, enabling these ABL-fusion proteins (X-ABL) to transform cells and to induce leukemia. The ABL kinase activity is blocked by the ABL kinase inhibitor STI571 which abrogates transformation by X-ABL. To investigate the role of oligomerization for the transformation potential of X-ABL and for the sensitivity to STI571, we constructed ABL chimeras with oligomerization interfaces of proteins involved in leukemia-associated translocations such as BCR, TEL, PML, and PLZF. We assessed the capacity of these chimeras to form high molecular weight (HMW) complexes as compared with p185(BCR-ABL). There was a direct relationship between the size of HMW complexes formed by these chimeras and their capacity to induce factor independence in Ba/F3 cells, whereas there was an inverse relationship between the size of the HMW complexes and the sensitivity to STI571. The targeting of the oligomerization interface of p185(BCR-ABL) by a peptide representing the coiled coil region of BCR reduced its potential to transform fibroblasts and increased sensitivity to STI571. Our results indicate that targeting of the oligomerization interfaces of the X-ABL enhances the effects of STI571 in the treatment of leukemia caused by X-ABL.

AP24534, a Pan-BCR-ABL Inhibitor for Chronic Myeloid Leukemia, Potently Inhibits the T315I Mutant and Overcomes Mutation-Based Resistance

PubMed Central

O’Hare, Thomas; Shakespeare, William C.; Zhu, Xiaotian; Eide, Christopher A.; Rivera, Victor M.; Wang, Frank; Adrian, Lauren T.; Zhou, Tianjun; Huang, Wei-Sheng; Xu, Qihong; Metcalf, Chester A.; Tyner, Jeffrey W.; Loriaux, Marc M.; Corbin, Amie S.; Wardwell, Scott; Ning, Yaoyu; Keats, Jeffrey A.; Wang, Yihan; Sundaramoorthi, Raji; Thomas, Mathew; Zhou, Dong; Snodgrass, Joseph; Commodore, Lois; Sawyer, Tomi K.; Dalgarno, David C.; Deininger, Michael W.N.; Druker, Brian J.; Clackson, Tim

2009-01-01

SUMMARY Inhibition of BCR-ABL by imatinib induces durable responses in many patients with chronic myeloid leukemia (CML), but resistance attributable to kinase domain mutations can lead to relapse and a switch to second-line therapy with nilotinib or dasatinib. Despite three approved therapeutic options, the cross-resistant BCR-ABLT315I mutation and compound mutants selected on sequential inhibitor therapy remain major clinical challenges. We report design and pre-clinical evaluation of AP24534, a potent, orally available multi-targeted kinase inhibitor active against T315I and other BCR-ABL mutants. AP24534 inhibited all tested BCR-ABL mutants in cellular and biochemical assays, suppressed BCR-ABLT315I-driven tumor growth in mice, and completely abrogated resistance in cell-based mutagenesis screens. Our work supports clinical evaluation of AP24534 as a pan-BCR-ABL inhibitor for treatment of CML. PMID:19878872

Dissection of the BCR-ABL signaling network using highly specific monobody inhibitors to the SHP2 SH2 domains.

PubMed

Sha, Fern; Gencer, Emel Basak; Georgeon, Sandrine; Koide, Akiko; Yasui, Norihisa; Koide, Shohei; Hantschel, Oliver

2013-09-10

The dysregulated tyrosine kinase BCR-ABL causes chronic myelogenous leukemia in humans and forms a large multiprotein complex that includes the Src-homology 2 (SH2) domain-containing phosphatase 2 (SHP2). The expression of SHP2 is necessary for BCR-ABL-dependent oncogenic transformation, but the precise signaling mechanisms of SHP2 are not well understood. We have developed binding proteins, termed monobodies, for the N- and C-terminal SH2 domains of SHP2. Intracellular expression followed by interactome analysis showed that the monobodies are essentially monospecific to SHP2. Two crystal structures revealed that the monobodies occupy the phosphopeptide-binding sites of the SH2 domains and thus can serve as competitors of SH2-phosphotyrosine interactions. Surprisingly, the segments of both monobodies that bind to the peptide-binding grooves run in the opposite direction to that of canonical phosphotyrosine peptides, which may contribute to their exquisite specificity. When expressed in cells, monobodies targeting the N-SH2 domain disrupted the interaction of SHP2 with its upstream activator, the Grb2-associated binder 2 adaptor protein, suggesting decoupling of SHP2 from the BCR-ABL protein complex. Inhibition of either N-SH2 or C-SH2 was sufficient to inhibit two tyrosine phosphorylation events that are critical for SHP2 catalytic activity and to block ERK activation. In contrast, targeting the N-SH2 or C-SH2 revealed distinct roles of the two SH2 domains in downstream signaling, such as the phosphorylation of paxillin and signal transducer and activator of transcription 5. Our results delineate a hierarchy of function for the SH2 domains of SHP2 and validate monobodies as potent and specific antagonists of protein-protein interactions in cancer cells.

Allosteric Inhibition of Bcr-Abl Kinase by High Affinity Monobody Inhibitors Directed to the Src Homology 2 (SH2)-Kinase Interface*

PubMed Central

Wojcik, John; Lamontanara, Allan Joaquim; Grabe, Grzegorz; Koide, Akiko; Akin, Louesa; Gerig, Barbara; Hantschel, Oliver; Koide, Shohei

2016-01-01

Bcr-Abl is a constitutively active kinase that causes chronic myelogenous leukemia. We have shown that a tandem fusion of two designed binding proteins, termed monobodies, directed to the interaction interface between the Src homology 2 (SH2) and kinase domains and to the phosphotyrosine-binding site of the SH2 domain, respectively, inhibits the Bcr-Abl kinase activity. Because the latter monobody inhibits processive phosphorylation by Bcr-Abl and the SH2-kinase interface is occluded in the active kinase, it remained undetermined whether targeting the SH2-kinase interface alone was sufficient for Bcr-Abl inhibition. To address this question, we generated new, higher affinity monobodies with single nanomolar KD values targeting the kinase-binding surface of SH2. Structural and mutagenesis studies revealed the molecular underpinnings of the monobody-SH2 interactions. Importantly, the new monobodies inhibited Bcr-Abl kinase activity in vitro and in cells, and they potently induced cell death in chronic myelogenous leukemia cell lines. This work provides strong evidence for the SH2-kinase interface as a pharmacologically tractable site for allosteric inhibition of Bcr-Abl. PMID:26912659

Biodegradable charged polyester-based vectors (BCPVs) as an efficient non-viral transfection nanoagent for gene knockdown of the BCR-ABL hybrid oncogene in a human chronic myeloid leukemia cell line

NASA Astrophysics Data System (ADS)

Yang, Chengbin; Panwar, Nishtha; Wang, Yucheng; Zhang, Butian; Liu, Maixian; Toh, Huiting; Yoon, Ho Sup; Tjin, Swee Chuan; Chong, Peter Han Joo; Law, Wing-Cheung; Chen, Chih-Kuang; Yong, Ken-Tye

2016-04-01

First-line therapy of chronic myelogenous leukemia (CML) has always involved the use of BCR-ABL tyrosine-kinase inhibitors which is associated with an abnormal chromosome called Philadelphia chromosome. Although the overall survival rate has been improved by the current therapeutic regime, the presence of resistance has resulted in limited efficacy. In this study, an RNA interference (RNAi)-based therapeutic regime is proposed with the aim to knockdown the BCR-ABL hybrid oncogene using small interfering RNA (siRNA). The siRNA transfection rates have usually been limited due to the declining contact probability among polyplexes and the non-adherent nature of leukemic cells. Our work aims at addressing this limitation by using a biodegradable charged polyester-based vector (BCPV) as a nanocarrier for the delivery of BCR-ABL-specific siRNA to the suspension culture of a K562 CML cell line. BCR-ABL siRNAs were encapsulated in the BCPVs by electrostatic force. Cell internalization was facilitated by the BCPV and assessed by confocal microscopy and flow cytometry. The regulation of the BCR-ABL level in K562 cells as a result of RNAi was analyzed by real-time polymerase chain reaction (RT-PCR). We observed that BCPV was able to form stable nanoplexes with siRNA molecules, even in the presence of fetal bovine serum (FBS), and successfully assisted in vitro siRNA transfection in the non-adherent K562 cells. As a consequence of downregulation of BCR-ABL, BCPV-siRNA nanoplexes inhibited cell proliferation and promoted cell apoptosis. All results were compared with a commercial transfection reagent, Lipofectamine2000™, which served as a positive control. More importantly, this class of non-viral vector exhibits biodegradable features and negligible cytotoxicity, thus providing a versatile platform to deliver siRNA to non-adherent leukemia cells with high transfection efficiency by effectively overcoming extra- and intra-cellular barriers. Due to the excellent in vitro transfection results from BCPV-siRNA, a newly developed biodegradable transfection agent, BCPV, is being probed for transfection performance in an animal model.

Molecular detection of BCR/ABL fusion gene in Saudi acute lymphoblastic leukemia patients.

PubMed

El-Sissy, Azza; El-Mashari, May; Bassuni, Wafaa; El-Swaayed, Aziza

2006-06-01

Molecular cytogenetics is becoming one of the most useful tools targeting some genes which are generally considered to lead to leukemic transformation (as well as for numerical abnormalities). A fraction of acute lymphoblastic leukemia (ALL) cases carry the translocation t(9;22) (q34;q11.2) which juxtaposes the ABL proto-oncogene to the BCR gene generating a chimeric gene, BCR/ABL. This aberration is more frequent in adult ALL (20%-40%) than in pediatric ALL (<5%), and predicts poor clinical outcome. AIM OF OUR WORK: Is to study BCR/ABL fusion gene in ALL cases using fluorescent in situ hybridization. Twenty newly diagnosed ALL patients, 16 adult and 4 paediatric cases, were included in the study, 11 cases (55%) were of precursor B phenotype, 8 cases (40%) belonged to T lineage, while one case was biphenotypic expressing mainly precursor B cell markers tether with CD13, CD33, CD117, Detection of BCR/ABL fusion gene was done using interphase FISH technique and was confirmed molecularly using the RT-PCR technique. BCR/ABL fusion gene was negative in all the examined cases, yet abnormality involving 9q34, ABL gene, either by addition or deletion was detected in three cases (15%). Two of these cases were associated with BCR gene extra copies (three and four copies, respectively). This may reflect the frequency of association of ABL gene and BCR gene abnormality in our cases, and that absence of fusion gene BCR/ABL does not exclude their role in the leukomogenic process, yet a larger study is required to confirm and detect the prevalence of these gene disturbances in ALL and their association.

The chimeric ubiquitin ligase SH2-U-box inhibits the growth of imatinib-sensitive and resistant CML by targeting the native and T315I-mutant BCR-ABL

PubMed Central

Ru, Yi; Wang, Qinhao; Liu, Xiping; Zhang, Mei; Zhong, Daixing; Ye, Mingxiang; Li, Yuanchun; Han, Hua; Yao, Libo; Li, Xia

2016-01-01

Chronic myeloid leukemia (CML) is characterized by constitutively active fusion protein tyrosine kinase BCR-ABL. Although the tyrosine kinase inhibitor (TKI) against BCR-ABL, imatinib, is the first-line therapy for CML, acquired resistance almost inevitably emerges. The underlying mechanism are point mutations within the BCR-ABL gene, among which T315I is notorious because it resists to almost all currently available inhibitors. Here we took use of a previously generated chimeric ubiquitin ligase, SH2-U-box, in which SH2 from the adaptor protein Grb2 acts as a binding domain for activated BCR-ABL, while U-box from CHIP functions as an E3 ubiquitin ligase domain, so as to target the ubiquitination and degradation of both native and T315I-mutant BCR-ABL. As such, SH2-U-box significantly inhibited proliferation and induced apoptosis in CML cells harboring either the wild-type or T315I-mutant BCR-ABL (K562 or K562R), with BCR-ABL-dependent signaling pathways being repressed. Moreover, SH2-U-box worked in concert with imatinib in K562 cells. Importantly, SH2-U-box-carrying lentivirus could markedly suppress the growth of K562-xenografts in nude mice or K562R-xenografts in SCID mice, as well as that of primary CML cells. Collectively, by degrading the native and T315I-mutant BCR-ABL, the chimeric ubiquitin ligase SH2-U-box may serve as a potential therapy for both imatinib-sensitive and resistant CML. PMID:27329306

The chimeric ubiquitin ligase SH2-U-box inhibits the growth of imatinib-sensitive and resistant CML by targeting the native and T315I-mutant BCR-ABL.

PubMed

Ru, Yi; Wang, Qinhao; Liu, Xiping; Zhang, Mei; Zhong, Daixing; Ye, Mingxiang; Li, Yuanchun; Han, Hua; Yao, Libo; Li, Xia

2016-06-22

Chronic myeloid leukemia (CML) is characterized by constitutively active fusion protein tyrosine kinase BCR-ABL. Although the tyrosine kinase inhibitor (TKI) against BCR-ABL, imatinib, is the first-line therapy for CML, acquired resistance almost inevitably emerges. The underlying mechanism are point mutations within the BCR-ABL gene, among which T315I is notorious because it resists to almost all currently available inhibitors. Here we took use of a previously generated chimeric ubiquitin ligase, SH2-U-box, in which SH2 from the adaptor protein Grb2 acts as a binding domain for activated BCR-ABL, while U-box from CHIP functions as an E3 ubiquitin ligase domain, so as to target the ubiquitination and degradation of both native and T315I-mutant BCR-ABL. As such, SH2-U-box significantly inhibited proliferation and induced apoptosis in CML cells harboring either the wild-type or T315I-mutant BCR-ABL (K562 or K562R), with BCR-ABL-dependent signaling pathways being repressed. Moreover, SH2-U-box worked in concert with imatinib in K562 cells. Importantly, SH2-U-box-carrying lentivirus could markedly suppress the growth of K562-xenografts in nude mice or K562R-xenografts in SCID mice, as well as that of primary CML cells. Collectively, by degrading the native and T315I-mutant BCR-ABL, the chimeric ubiquitin ligase SH2-U-box may serve as a potential therapy for both imatinib-sensitive and resistant CML.

aCGH Local Copy Number Aberrations Associated with Overall Copy Number Genomic Instability in Colorectal Cancer: Coordinate Involvement of the Regions Including BCR and ABL

PubMed Central

Bartos, Jeremy D.; Gaile, Daniel P.; McQuaid, Devin E.; Conroy, Jeffrey M.; Darbary, Huferesh; Nowak, Norma J.; Block, Annemarie; Petrelli, Nicholas J.; Mittelman, Arnold; Stoler, Daniel L.; Anderson, Garth R.

2007-01-01

In order to identify small regions of the genome whose specific copy number alteration is associated with high genomic instability in the form of overall genome-wide copy number aberrations, we have analyzed array-based comparative genomic hybridization (aCGH) data from 33 sporadic colorectal carcinomas. Copy number changes of a small number of specific regions were significantly correlated with elevated overall amplifications and deletions scattered throughout the entire genome. One significant region at 9q34 includes the c-ABL gene Another region spanning 22q11–13 includes the breakpoint cluster region (BCR) of the Philadelphia chromosome Coordinate 22q11–13 alterations were observed in nine of eleven tumors with the 9q34 alteration Additional regions on 1q and 14q were associated with overall genome-wide copy number changes, while copy number aberrations on chromosome 7p, 7q, and 13q21.1–31.3 were found associated with this instability only in tumors from patients with a smoking history Our analysis demonstrates there are a small number of regions of the genome where gain or loss is commonly associated with a tumor’s overall level of copy number aberrations Our finding BCR and ABL located within two of the instability-associated regions, and the involvement of these two regions occurring coordinately, suggests a system akin to the BCR-ABL translocation of CML may be involved in genomic instability in about one-third of human colorectal carcinomas. PMID:17196995

Bone marrow niche trafficking of miR-126 controls the self-renewal of leukemia stem cells in chronic myelogenous leukemia.

PubMed

Zhang, Bin; Nguyen, Le Xuan Truong; Li, Ling; Zhao, Dandan; Kumar, Bijender; Wu, Herman; Lin, Allen; Pellicano, Francesca; Hopcroft, Lisa; Su, Yu-Lin; Copland, Mhairi; Holyoake, Tessa L; Kuo, Calvin J; Bhatia, Ravi; Snyder, David S; Ali, Haris; Stein, Anthony S; Brewer, Casey; Wang, Huafeng; McDonald, Tinisha; Swiderski, Piotr; Troadec, Estelle; Chen, Ching-Cheng; Dorrance, Adrienne; Pullarkat, Vinod; Yuan, Yate-Ching; Perrotti, Danilo; Carlesso, Nadia; Forman, Stephen J; Kortylewski, Marcin; Kuo, Ya-Huei; Marcucci, Guido

2018-05-01

Leukemia stem cells (LSCs) in individuals with chronic myelogenous leukemia (CML) (hereafter referred to as CML LSCs) are responsible for initiating and maintaining clonal hematopoiesis. These cells persist in the bone marrow (BM) despite effective inhibition of BCR-ABL kinase activity by tyrosine kinase inhibitors (TKIs). Here we show that although the microRNA (miRNA) miR-126 supported the quiescence, self-renewal and engraftment capacity of CML LSCs, miR-126 levels were lower in CML LSCs than in long-term hematopoietic stem cells (LT-HSCs) from healthy individuals. Downregulation of miR-126 levels in CML LSCs was due to phosphorylation of Sprouty-related EVH1-domain-containing 1 (SPRED1) by BCR-ABL, which led to inhibition of the RAN-exportin-5-RCC1 complex that mediates miRNA maturation. Endothelial cells (ECs) in the BM supply miR-126 to CML LSCs to support quiescence and leukemia growth, as shown using mouse models of CML in which Mir126a (encoding miR-126) was conditionally knocked out in ECs and/or LSCs. Inhibition of BCR-ABL by TKI treatment caused an undesired increase in endogenous miR-126 levels, which enhanced LSC quiescence and persistence. Mir126a knockout in LSCs and/or ECs, or treatment with a miR-126 inhibitor that targets miR-126 expression in both LSCs and ECs, enhanced the in vivo anti-leukemic effects of TKI treatment and strongly diminished LSC leukemia-initiating capacity, providing a new strategy for the elimination of LSCs in individuals with CML.

Selective Depletion of CD45RA+ T Cells From Allogeneic Peripheral Blood Stem Cell Grafts From HLA-Matched Related and Unrelated Donors in Preventing GVHD

ClinicalTrials.gov

2017-10-25

Accelerated Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Acute Biphenotypic Leukemia; Acute Leukemia of Ambiguous Lineage; Acute Undifferentiated Leukemia; Adult Acute Lymphoblastic Leukemia in Remission; Adult Acute Myeloid Leukemia in Remission; Blast Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Blastic Plasmacytoid Dendritic Cell Neoplasm; Childhood Acute Lymphoblastic Leukemia in Remission; Childhood Acute Myeloid Leukemia in Remission; Lymphoblastic Lymphoma; Myelodysplastic Syndrome With Excess Blasts; Myelodysplastic Syndrome With Excess Blasts-1; Myelodysplastic Syndrome With Excess Blasts-2; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Recurrent Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Refractory Acute Lymphoblastic Leukemia; Refractory Acute Myeloid Leukemia

[JAK2 V617F and exon 12 genetic variations in Korean patients with BCR/ABL1-negative myeloproliferative neoplasms].

PubMed

Kim, Jeong Tae; Cho, Yong Gon; Choi, Sam Im; Lee, Young Jin; Kim, Hye Ran; Jang, Sook Jin; Moon, Dae Soo; Park, Young Jin; Park, Geon

2010-12-01

JAK2 genetic variations have been described in a high proportion of patients with BCR/ABL1-negative myeloproliferative neoplasms (MPN). This study was designed to analyze the frequencies of JAK2 V617F and exon 12 variations, and their correlations with clinical characteristics of Korean patients with BCR/ABL1-negative MPN. We examined a total of 154 patients with BCR/ABL1-negative MPN that included 24, 26, 89, and 15 patients with polycythemia vera (PV), primary myelofibrosis (PMF), essential thrombocythemia (ET), and unclassified myeloproliferative neoplasms (MPNU), respectively. We performed allele-specific PCR to detect V617F in all BCR/ABL1-negative patients, and performed direct sequencing to detect exon 12 variations in 47 V617F-negative MPN patients. JAK2 c.1641+179_183del5 variation was detected by restriction fragment length polymorphism assay in 176 healthy subjects. JAK2 V617F was detected in 91 patients (59.1%): PV (91.6%), PMF (46.2%), ET (52.8%), and MPNU (66.7%). In V617F-negative MPN patients, no mutations were found in exon 12. The c.1641+179_183del5 was detected in 68.1% of V617F-negative MPN patients and 45.4% of healthy subjects (P=0.008). JAK2 V617F was closely correlated with age and leukocytosis in BCR/ABL1-negative MPN patients (P<0.05). However, c.1641+179_183del5 was not related to age, sex, or complete blood cell count parameters in V617F-negative MPN patients and healthy subjects. The c.1641+179_183del5 was associated with an increased odds ratio for MPN (odds ratio, 2.6; 95% confidences interval, 1.3-5.1; P=0.007). Frequencies of V617F are similar to reported results. JAK2 exon 12 mutations may be rare and c.1641+179_183del5 may influence the occurrence of MPN in Korean patients with V6 17F-negative MPN.

Essential role for Stat5a/b in myeloproliferative neoplasms induced by BCR-ABL1 and JAK2V617F in mice

PubMed Central

Walz, Christoph; Ahmed, Wesam; Lazarides, Katherine; Betancur, Monica; Patel, Nihal; Hennighausen, Lothar; Zaleskas, Virginia M.

2012-01-01

STAT5 proteins are constitutively activated in malignant cells from many patients with leukemia, including the myeloproliferative neoplasms (MPNs) chronic myeloid leukemia (CML) and polycythemia vera (PV), but whether STAT5 is essential for the pathogenesis of these diseases is not known. In the present study, we used mice with a conditional null mutation in the Stat5a/b gene locus to determine the requirement for STAT5 in MPNs induced by BCR-ABL1 and JAK2V617F in retroviral transplantation models of CML and PV. Loss of one Stat5a/b allele resulted in a decrease in BCR-ABL1–induced CML-like MPN and the appearance of B-cell acute lymphoblastic leukemia, whereas complete deletion of Stat5a/b prevented the development of leukemia in primary recipients. However, BCR-ABL1 was expressed and active in Stat5-null leukemic stem cells, and Stat5 deletion did not prevent progression to lymphoid blast crisis or abolish established B-cell acute lymphoblastic leukemia. JAK2V617F failed to induce polycythemia in recipients after deletion of Stat5a/b, although the loss of STAT5 did not prevent the development of myelofibrosis. These results demonstrate that STAT5a/b is essential for the induction of CML-like leukemia by BCR-ABL1 and of polycythemia by JAK2V617F, and validate STAT5a/b and the genes they regulate as targets for therapy in these MPNs. PMID:22234689

Integrative epigenomic analysis identifies biomarkers and therapeutic targets in adult B-acute lymphoblastic leukemia

PubMed Central

Geng, Huimin; Brennan, Sarah; Milne, Thomas A.; Chen, Wei-Yi; Li, Yushan; Hurtz, Christian; Kweon, Soo-Mi; Zickl, Lynette; Shojaee, Seyedmehdi; Neuberg, Donna; Huang, Chuanxin; Biswas, Debabrata; Xin, Yuan; Racevskis, Janis; Ketterling, Rhett P.; Luger, Selina M.; Lazarus, Hillard; Tallman, Martin S.; Rowe, Jacob M.; Litzow, Mark R.; Guzman, Monica L.; Allis, C. David; Roeder, Robert G.; Müschen, Markus; Paietta, Elisabeth; Elemento, Olivier; Melnick, Ari M.

2012-01-01

Genetic lesions such as BCR-ABL1, E2A-PBX1 and MLL rearrangements (MLLr) are associated with unfavorable outcomes in adult B-acute lymphoblastic leukemia (B-ALL). Leukemia oncoproteins may directly or indirectly disrupt cytosine methylation patterning to mediate the malignant phenotype. We postulated that DNA methylation signatures in these aggressive B-ALLs would point towards disease mechanisms and useful biomarkers and therapeutic targets. We therefore performed DNA methylation and gene expression profiling on a cohort of 215 adult B-ALL patients enrolled in a single phase III clinical trial (ECOG E2993) and normal control B-cells. In BCR-ABL1-positive B-ALL, aberrant cytosine methylation patterning centered around a cytokine network defined by hypomethylation and overexpression of IL2RA(CD25). The E2993 trial clinical data showed that CD25 expression was strongly associated with a poor outcome in ALL patients regardless of BCR-ABL1 status, suggesting CD25 as a novel prognostic biomarker for risk stratification in B-ALL. In E2A-PBX1-positive B-ALL, aberrant DNA methylation patterning was strongly associated with direct fusion protein binding as shown by the E2A-PBX1 ChIP sequencing (ChIP-seq), suggesting that E2A-PBX1 fusion protein directly remodels the epigenome to impose an aggressive B-ALL phenotype. MLLr B-ALL featured prominent cytosine hypomethylation, which was linked with MLL fusion protein binding, H3K79 dimethylation and transcriptional upregulation, affecting a set of known and newly identified MLL fusion direct targets with oncogenic activity such as FLT3 and BCL6. Notably, BCL6 blockade or loss of function suppressed proliferation and survival of MLLr leukemia cells, suggesting BCL6 targeted therapy as a new therapeutic strategy for MLLr B-ALL. PMID:23107779

Efficacy and Pharmacologic Data of Second-Generation Tyrosine Kinase Inhibitor Nilotinib in BCR-ABL-Positive Leukemia Patients with Central Nervous System Relapse after Allogeneic Stem Cell Transplantation

PubMed Central

Reinwald, Mark; Schleyer, Eberhard; Kiewe, Philipp; Blau, Igor Wolfgang; Burmeister, Thomas; Pursche, Stefan; Neumann, Martin; Notter, Michael; Thiel, Eckhard; Hofmann, Wolf-Karsten; Kolb, Hans-Jochem; Burdach, Stefan; Bender, Hans-Ulrich

2014-01-01

Central nervous system (CNS) involvement is a severe complication of BCR-ABL-positive leukemia after allogenic stem cell transplantation (alloSCT) associated with fatal outcome. Although second-generation tyrosine-kinase inhibitors (TKI) such as nilotinib have shown activity in systemic BCR-ABL+ disease, little data exists on their penetration and efficacy within the CNS. Four patients (3 male, 1 female; age 15–49) with meningeal relapse after alloSCT and subsequent treatment with nilotinib were identified. A total of 17 cerebrospinal fluid (csf) and serum samples were assessed for nilotinib concentration and patient outcome was recorded. Nilotinib concentrations showed a low median csf/plasma ratio of 0.53% (range 0.23–1.5%), yet pronounced clinical efficacy was observed with long-lasting responses (>1 year) in three patients. Comparison with historical data showed a trend towards superior efficacy of nilotinib versus imatinib. Despite poor csf penetration, nilotinib showed significant clinical activity in CNS relapse of BCR-ABL+ leukemias. As nilotinib has a high protein-binding affinity, the low-protein concentration in csf could translate into a relatively higher amount of free and therefore active nilotinib in csf as compared to blood, possibly explaining the observed efficacy. Thus, treatment with a 2nd generation TKI warrants further investigation and should be considered in cases of CNS relapse of BCR-ABL-positive leukemia after alloSCT. PMID:25025064

Multi-antigen CMV-MVA Triplex Vaccine in Reducing CMV Complications in Patients Previously Infected With CMV and Undergoing Donor Hematopoietic Cell Transplant

ClinicalTrials.gov

2018-05-04

Accelerated Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Acute Lymphoblastic Leukemia in Remission; Acute Myeloid Leukemia in Remission; Chronic Lymphocytic Leukemia; Chronic Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Cytomegaloviral Infection; Hodgkin Lymphoma; Lymphadenopathy; Lymphoblastic Lymphoma; Myelodysplastic Syndrome; Myelofibrosis; Myeloproliferative Neoplasm; Non-Hodgkin Lymphoma

Multi-peptide CMV-Modified Vaccinia Ankara Vaccine in Reducing CMV Related Complications in Patients With Blood Cancer Undergoing Donor Stem Cell Transplant

ClinicalTrials.gov

2018-02-16

Accelerated Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Acute Lymphoblastic Leukemia in Remission; Acute Myeloid Leukemia in Remission; Bone Marrow Transplantation Recipient; Chronic Lymphocytic Leukemia; Chronic Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Hematopoietic Cell Transplantation Recipient; Hodgkin Lymphoma; Myelodysplastic Syndrome; Myelofibrosis; Myeloproliferative Neoplasm; Non-Hodgkin Lymphoma

Strategies to circumvent the T315I gatekeeper mutation in the Bcr-Abl tyrosine kinase

PubMed Central

Bose, Prithviraj; Park, Haeseong; Al-Khafaji, Jawad; Grant, Steven

2013-01-01

Despite the remarkable success of imatinib against Bcr-Abl, development of secondary resistance, most often due to point mutations in the Bcr-Abl tyrosine kinase (TK) domain, is quite common. Of these, the T315I “gatekeeper” mutation is resistant to all currently registered Bcr-Abl TK inhibitors (TKIs) with the notable exception of ponatinib (Iclusig™), which was very recently approved by the United States Food and Drug Administration (FDA). Besides ponatinib, numerous strategies have been developed to circumvent this problem. These include the protein synthesis inhibitor omacetaxine (Synribo®), and “switch-control” inhibitors. Dual Bcr-Abl and aurora kinase inhibitors represent another promising strategy. Finally, several promising synergistic combinations, such as TKIs with histone deacetylase inhibitors (HDACIs), warrant attention. PMID:23977454

The novel anticancer agent JNJ-26854165 is active in chronic myeloid leukemic cells with unmutated BCR/ABL and T315I mutant BCR/ABL through promoting proteosomal degradation of BCR/ABL proteins.

PubMed

You, Liangshun; Liu, Hui; Huang, Jian; Xie, Wanzhuo; Wei, Jueying; Ye, Xiujin; Qian, Wenbin

2017-01-31

Chronic myeloid leukemia (CML) is a clonal malignant disease caused by the expression of BCR/ABL. MDM2 (human homolog of the murine double minute-2) inhibitors such as Nutlin-3 have been shown to induce apoptosis in a p53-dependent manner in CML cells and sensitize cells to Imatinib. Here, we demonstrate that JNJ-26854165, an inhibitor of MDM2, inhibits proliferation and triggers cell death in a p53-independent manner in various BCR/ABL-expressing cells, which include primary leukemic cells from patients with CML blast crisis and cells expressing the Imatinib-resistant T315I BCR/ABL mutant. The response to JNJ-26854165 is associated with the downregulation of BCR/ABL dependently of proteosome activation. Moreover, in all tested CML cells, with the exception of T315I mutation cells, combining JNJ-26854165 and tyrosine kinase inhibitor (TKI) Imatinib or PD180970 leads to a synergistic effect. In conclusion, our results suggest that JNJ-26854165, used either alone or in combination with TKIs, represents a promising novel targeted approach to overcome TKI resistance and improve patient outcome in CML.

Allosteric Inhibition of Bcr-Abl Kinase by High Affinity Monobody Inhibitors Directed to the Src Homology 2 (SH2)-Kinase Interface.

PubMed

Wojcik, John; Lamontanara, Allan Joaquim; Grabe, Grzegorz; Koide, Akiko; Akin, Louesa; Gerig, Barbara; Hantschel, Oliver; Koide, Shohei

2016-04-15

Bcr-Abl is a constitutively active kinase that causes chronic myelogenous leukemia. We have shown that a tandem fusion of two designed binding proteins, termed monobodies, directed to the interaction interface between the Src homology 2 (SH2) and kinase domains and to the phosphotyrosine-binding site of the SH2 domain, respectively, inhibits the Bcr-Abl kinase activity. Because the latter monobody inhibits processive phosphorylation by Bcr-Abl and the SH2-kinase interface is occluded in the active kinase, it remained undetermined whether targeting the SH2-kinase interface alone was sufficient for Bcr-Abl inhibition. To address this question, we generated new, higher affinity monobodies with single nanomolar KD values targeting the kinase-binding surface of SH2. Structural and mutagenesis studies revealed the molecular underpinnings of the monobody-SH2 interactions. Importantly, the new monobodies inhibited Bcr-Abl kinase activity in vitro and in cells, and they potently induced cell death in chronic myelogenous leukemia cell lines. This work provides strong evidence for the SH2-kinase interface as a pharmacologically tractable site for allosteric inhibition of Bcr-Abl. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Design, Synthesis, and Biological Evaluation of Novel 1,3,4-Thiadiazole Derivatives as Potential Antitumor Agents against Chronic Myelogenous Leukemia: Striking Effect of Nitrothiazole Moiety

DOE PAGES

Altıntop, Mehlika; Ciftci, Halil; Radwan, Mohamed; ...

2017-12-27

In an attempt to develop potent antitumor agents, new 1,3,4-thiadiazole derivatives were synthesized and evaluated for their cytotoxic effects on multiple human cancer cell lines, including the K562 chronic myelogenous leukemia cell line that expresses the Bcr-Abl tyrosine kinase. N-(5-Nitrothiazol-2-yl)-2-((5-((4-(trifluoromethyl)phenyl)amino)-1,3,4-thiadiazol-2-yl)thio)acetamide (2) inhibited the Abl protein kinase with an IC 50 value of 7.4 µM and showed selective activity against the Bcr-Abl positive K562 cell line. Furthermore, a Bcr-Abl-compound 2 molecular modelling simulation highlighted the anchoring role of the nitrothiazole moiety in bonding and hydrophobic interaction with the key amino acid residues. These results provide promising starting points for further developmentmore » of novel kinase inhibitors.« less

Design, Synthesis, and Biological Evaluation of Novel 1,3,4-Thiadiazole Derivatives as Potential Antitumor Agents against Chronic Myelogenous Leukemia: Striking Effect of Nitrothiazole Moiety

DOE Office of Scientific and Technical Information (OSTI.GOV)

Altıntop, Mehlika; Ciftci, Halil; Radwan, Mohamed

In an attempt to develop potent antitumor agents, new 1,3,4-thiadiazole derivatives were synthesized and evaluated for their cytotoxic effects on multiple human cancer cell lines, including the K562 chronic myelogenous leukemia cell line that expresses the Bcr-Abl tyrosine kinase. N-(5-Nitrothiazol-2-yl)-2-((5-((4-(trifluoromethyl)phenyl)amino)-1,3,4-thiadiazol-2-yl)thio)acetamide (2) inhibited the Abl protein kinase with an IC 50 value of 7.4 µM and showed selective activity against the Bcr-Abl positive K562 cell line. Furthermore, a Bcr-Abl-compound 2 molecular modelling simulation highlighted the anchoring role of the nitrothiazole moiety in bonding and hydrophobic interaction with the key amino acid residues. These results provide promising starting points for further developmentmore » of novel kinase inhibitors.« less

Involvement of SLP-65 and Btk in tumor suppression and malignant transformation of pre-B cells.

PubMed

Hendriks, Rudi W; Kersseboom, Rogier

2006-02-01

Signals from the precursor-B cell receptor (pre-BCR) are essential for selection and clonal expansion of pre-B cells that have performed productive immunoglobulin heavy chain V(D)J recombination. In the mouse, the downstream signaling molecules SLP-65 and Btk cooperate to limit proliferation and induce differentiation of pre-B cells, thereby acting as tumor suppressors to prevent pre-B cell leukemia. In contrast, recent observations in human BCR-ABL1(+) pre-B lymphoblastic leukemia cells demonstrate that Btk is constitutively phosphorylated and activated by the BCR-ABL1 fusion protein. As a result, activated Btk transmits survival signals that are essential for the transforming activity of oncogenic Abl tyrosine kinase.

Coupling between p210bcr-abl and Shc and Grb2 adaptor proteins in hematopoietic cells permits growth factor receptor-independent link to ras activation pathway.

PubMed

Tauchi, T; Boswell, H S; Leibowitz, D; Broxmeyer, H E

1994-01-01

Enforced expression of p210bcr-abl transforms interleukin 3 (IL-3)-dependent hematopoietic cell lines to growth factor-independent proliferation. It has been demonstrated that nonreceptor tyrosine kinase oncogenes may couple to the p21ras pathway to exert their transforming effect. In particular, p210bcr-abl was recently found to effect p21ras activation in hematopoietic cells. In this context, experiments were performed to evaluate a protein signaling pathway by which p210bcr-abl might regulate p21ras. It was asked whether Shc p46/p52, a protein containing a src-homology region 2 (SH2) domain, and known to function upstream from p21ras, might form specific complexes with p210bcr-abl and thus, possibly alter p21ras activity by coupling to the guanine nucleotide exchange factor (Sos/CDC25) through the Grb2 protein-Sos complex. This latter complex has been previously demonstrated to occur ubiquitously. We found that p210bcr-abl formed a specific complex with Shc and with Grb2 in three different murine cell lines transfected with a p210bcr-abl expression vector. There appeared to be a higher order complex containing Shc, Grb2, and bcr-abl proteins. In contrast to p210bcr-abl transformed cells, in which there was constitutive tight association between Grb2 and Shc, binding between Grb2 and Shc was Steel factor (SLF)-dependent in a SLF-responsive, nontransformed parental cell line. The SLF-dependent association between Grb2 and Shc in nontransformed cells involved formation of a complex of Grb2 with c-kit receptor after SLF treatment. Thus, p210bcr-abl appears to function in a hematopoietic p21ras activation pathway to allow growth factor-independent coupling between Grb2, which exists in a complex with the guanine nucleotide exchange factor (Sos), and p21ras. Shc may not be required for Grb2-c-kit interaction, because it fails to bind strongly to c-kit.

Belinostat and Azacitidine in Treating Patients With Advanced Hematologic Cancers or Other Diseases

ClinicalTrials.gov

2014-12-22

Accelerated Phase of Disease; Adult Acute Myeloid Leukemia With Inv(16)(p13.1q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With t(16;16)(p13.1;q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); RUNX1-RUNX1T1; Adult Acute Myeloid Leukemia With t(9;11)(p22;q23); MLLT3-MLL; Adult Acute Promyelocytic Leukemia With t(15;17)(q22;q12); PML-RARA; Atypical Chronic Myeloid Leukemia, BCR-ABL1 Negative; Blastic Phase; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Chronic Myelomonocytic Leukemia; de Novo Myelodysplastic Syndrome; Myelodysplastic/Myeloproliferative Neoplasm, Unclassifiable; Philadelphia Chromosome Negative, BCR-ABL1 Positive Chronic Myelogenous Leukemia; Previously Treated Myelodysplastic Syndrome; Primary Myelofibrosis; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Disease; Secondary Acute Myeloid Leukemia; Secondary Myelodysplastic Syndrome

A derivative of epigallocatechin-3-gallate induces apoptosis via SHP-1-mediated suppression of BCR-ABL and STAT3 signalling in chronic myelogenous leukaemia

PubMed Central

Jung, Ji Hoon; Yun, Miyong; Choo, Eun-Jeong; Kim, Sun-Hee; Jeong, Myoung-Seok; Jung, Deok-Beom; Lee, Hyemin; Kim, Eun-Ok; Kato, Nobuo; Kim, Bonglee; Srivastava, Sanjay K; Kaihatsu, Kunihiro; Kim, Sung-Hoon

2015-01-01

Background and Purpose Epigallocatechin-3-gallate (EGCG) is a component of green tea known to have chemo-preventative effects on several cancers. However, EGCG has limited clinical application, which necessitates the development of a more effective EGCG prodrug as an anticancer agent. Experimental Approach Derivatives of EGCG were evaluated for their stability and anti-tumour activity in human chronic myeloid leukaemia (CML) K562 and KBM5 cells. Key Results EGCG-mono-palmitate (EGCG-MP) showed most prolonged stability compared with other EGCG derivatives. EGCG-MP exerted greater cytotoxicity and apoptosis in K562 and KBM5 cells than the other EGCG derivatives. EGCG-MP induced Src-homology 2 domain-containing tyrosine phosphatase 1 (SHP-1) leading decreased oncogenic protein BCR-ABL and STAT3 phosphorylation in CML cells, compared with treatment with EGCG. Furthermore, EGCG-MP reduced phosphorylation of STAT3 and survival genes in K562 cells, compared with EGCG. Conversely, depletion of SHP-1 or application of the tyrosine phosphatase inhibitor pervanadate blocked the ability of EGCG-MP to suppress phosphorylation of BCR-ABL and STAT3, and the expression of survival genes downstream of STAT3. In addition, EGCG-MP treatment more effectively suppressed tumour growth in BALB/c athymic nude mice compared with untreated controls or EGCG treatment. Immunohistochemistry revealed increased caspase 3 and SHP-1 activity and decreased phosphorylation of BCR-ABL in the EGCG-MP-treated group relative to that in the EGCG-treated group. Conclusions and Implications EGCG-MP induced SHP-1-mediated inhibition of BCR-ABL and STAT3 signalling in vitro and in vivo more effectively than EGCG. This derivative may be a potent chemotherapeutic agent for CML treatment. PMID:25825203

Nilotinib: optimal therapy for patients with chronic myeloid leukemia and resistance or intolerance to imatinib.

PubMed

Swords, Ronan; Mahalingam, Devalingam; Padmanabhan, Swaminathan; Carew, Jennifer; Giles, Francis

2009-09-21

Chronic myeloid leukemia (CML) is the consequence of a single balanced translocation that produces the BCR-ABL fusion oncogene which is detectable in over 90% of patients at presentation. The BCR-ABL inhibitor imatinib mesylate (IM) has improved survival in all phases of CML and is the standard of care for newly diagnosed patients in chronic phase. Despite the very significant therapeutic benefits of IM, a small minority of patients with early stage disease do not benefit optimally while IM therapy in patients with advanced disease is of modest benefit in many. Diverse mechanisms may be responsible for IM failures, with point mutations within the Bcr-Abl kinase domain being amongst the most common resistance mechanisms described in patients with advanced CML. The development of novel agents designed to overcome IM resistance, while still primarily targeted on BCR-ABL, led to the creation of the high affinity aminopyrimidine inhibitor, nilotinib. Nilotinib is much more potent as a BCR-ABL inhibitor than IM and inhibits both wild type and IM-resistant BCR-ABL with significant clinical activity across the entire spectrum of BCR-ABL mutants with the exception of T315I. The selection of a second generation tyrosine kinase inhibitor to rescue patients with imatinib failure will be based on several factors including age, co-morbid medical problems and ABL kinase mutational profile. It should be noted that while the use of targeted BCR-ABL kinase inhibitors in CML represents a paradigm shift in CML management these agents are not likely to have activity against the quiescent CML stem cell pool. The purpose of this review is to summarize the pre-clinical and clinical data on nilotinib in patients with CML who have failed prior therapy with IM or dasatinib.

Targetable kinase-activating lesions in Ph-like acute lymphoblastic leukemia | Office of Cancer Genomics

Cancer.gov

Publication Abstract:  Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is characterized by a gene-expression profile similar to that of BCR-ABL1-positive ALL, alterations of lymphoid transcription factor genes, and a poor outcome. The frequency and spectrum of genetic alterations in Ph-like ALL and its responsiveness to tyrosine kinase inhibition are undefined, especially in adolescents and adults. We performed genomic profiling of 1725 patients with precursor B-cell ALL and detailed genomic analysis of 154 patients with Ph-like ALL.

Clinical characteristics of patients with central nervous system relapse in BCR-ABL1-positive acute lymphoblastic leukemia: the importance of characterizing ABL1 mutations in cerebrospinal fluid.

PubMed

Sanchez, Ricardo; Ayala, Rosa; Alonso, Rafael Alberto; Martínez, María Pilar; Ribera, Jordi; García, Olga; Sanchez-Pina, José; Mercadal, Santiago; Montesinos, Pau; Martino, Rodrigo; Barba, Pere; González-Campos, José; Barrios, Manuel; Lavilla, Esperanza; Gil, Cristina; Bernal, Teresa; Escoda, Lourdes; Abella, Eugenia; Amigo, Ma Luz; Moreno, Ma José; Bravo, Pilar; Guàrdia, Ramón; Hernández-Rivas, Jesús-María; García-Guiñón, Antoni; Piernas, Sonia; Ribera, José-María; Martínez-López, Joaquín

2017-07-01

We investigated the frequency, predictors, and evolution of acute lymphoblastic leukemia (ALL) in patients with CNS relapse and introduced a novel method for studying BCR-ABL1 protein variants in cDNA from bone marrow (BM) and cerebrospinal fluid (CSF) blast cells. A total of 128 patients were analyzed in two PETHEMA clinical trials. All achieved complete remission after imatinib treatment. Of these, 30 (23%) experienced a relapse after achieving complete remission, and 13 (10%) had an isolated CNS relapse or combined CNS and BM relapses. We compared the characteristics of patients with and without CNS relapse and further analyzed CSF and BM samples from two of the 13 patients with CNS relapse. In both patients, classical sequencing analysis of the kinase domain of BCR-ABL1 from the cDNA of CSF blasts revealed the pathogenic variant p.L387M. We also performed ultra-deep next-generation sequencing (NGS) in three samples from one of the relapsed patients. We did not find the mutation in the BM sample, but we did find it in CSF blasts with 45% of reads at the time of relapse. These data demonstrate the feasibility of detecting BCR-ABL1 mutations in CSF blasts by NGS and highlight the importance of monitoring clonal evolution over time.

Blinatumomab and Nivolumab With or Without Ipilimumab in Treating Patients With Poor-Risk Relapsed or Refractory CD19+ Precursor B-Lymphoblastic Leukemia

ClinicalTrials.gov

2018-05-14

B Acute Lymphoblastic Leukemia; B Acute Lymphoblastic Leukemia With t(9;22)(q34.1;q11.2); BCR-ABL1; CD19-Positive Neoplastic Cells Present; Mixed Phenotype Acute Leukemia; Mixed Phenotype Acute Leukemia With t(9;22)(q34.1;q11.2); BCR-ABL1; Recurrent B Acute Lymphoblastic Leukemia; Refractory B Acute Lymphoblastic Leukemia

'Real-life' study of imatinib therapy in chronic phase-chronic myeloid leukemia: A novel retrospective observational longitudinal analysis.

PubMed

Merante, Serena; Ferretti, Virginia; Elena, Chiara; Calvello, Celeste; Rocca, Barbara; Zappatore, Rita; Cavigliano, Paola; Orlandi, Ester

2017-01-01

Imatinib is a cornerstone of treatment of chronic myeloid leukemia. It remains unclear whether transient treatment discontinuation or dose changes affect outcome and this approach has not yet been approved for use outside clinical trials. We conducted a retrospective single-institution observational study to evaluate factors affecting response in 'real-life' clinical practice in 138 chronic myeloid leukemia patients in chronic phase treated with imatinib. We used a novel longitudinal data analytical model, with a generalized estimating equation model, to study BCR-ABL variation according to continuous standard dose, change in dose or discontinuation; BCR-ABL transcript levels were recorded. Treatment history was subdivided into time periods for which treatment was given at constant dosage (total 483 time periods). Molecular and cytogenetic complete response was observed after 154 (32%) and 358 (74%) time periods, respectively. After adjusting for length of time period, no association between dose and cytogenetic complete response rate was observed. There was a significantly lower molecular complete response rate after time periods at a high imatinib dosage. This statistical approach can identify individual patient variation in longitudinal data collected over time and suggests that changes in dose or discontinuation of therapy could be considered in patients with appropriate biological characteristics.

Presence of novel compound BCR-ABL mutations in late chronic and advanced phase imatinib sensitive CML patients indicates their possible role in CML progression.

PubMed

Akram, Afia Muhammad; Iqbal, Zafar; Akhtar, Tanveer; Khalid, Ahmed Mukhtar; Sabar, Muhammad Farooq; Qazi, Mahmood Hussain; Aziz, Zeba; Sajid, Nadia; Aleem, Aamer; Rasool, Mahmood; Asif, Muhammad; Aloraibi, Saleh; Aljamaan, Khaled; Iqbal, Mudassar

2017-04-03

BCR-ABL kinase domain (K D ) mutations are well known for causing resistance against tyrosine kinase inhibitors (TKIs) and disease progression in chronic myeloid leukemia (CML). In recent years, compound BCR-ABL mutations have emerged as a new threat to CML patients by causing higher degrees of resistance involving multiple TKIs, including ponatinib. However, there are limited reports about association of compound BCR-ABL mutations with disease progression in imatinib (IM) sensitive CML patients. Therefore, we investigated presence of ABL-K D mutations in chronic phase (n = 41), late chronic phase (n = 33) and accelerated phase (n = 16) imatinib responders. Direct sequencing analysis was used for this purpose. Eleven patients (12.22%) in late-CP CML were detected having total 24 types of point mutations, out of which 8 (72.72%) harbored compound mutated sites. SH2 contact site mutations were dominant in our study cohort, with E355G (3.33%) being the most prevalent. Five patients (45%) all having compound mutated sites, progressed to advanced phases of disease during follow up studies. Two novel silent mutations G208G and E292E/E were detected in combination with other mutants, indicating limited tolerance for BCR-ABL1 kinase domain for missense mutations. However, no patient in early CP of disease manifested mutated ABL-K D . Occurrence of mutations was found associated with elevated platelet count (p = 0.037) and patients of male sex (p = 0.049). The median overall survival and event free survival of CML patients (n = 90) was 6.98 and 5.8 y respectively. The compound missense mutations in BCR-ABL kinase domain responsible to elicit disease progression, drug resistance or disease relapse in CML, can be present in yet Imatinib sensitive patients. Disease progression observed here, emphasizes the need of ABL-K D mutation screening in late chronic phase CML patients for improved clinical management of disease.

CLL Cells Respond to B-Cell Receptor Stimulation with a MicroRNA/mRNA Signature Associated with MYC Activation and Cell Cycle Progression

PubMed Central

Pede, Valerie; Rombout, Ans; Vermeire, Jolien; Naessens, Evelien; Mestdagh, Pieter; Robberecht, Nore; Vanderstraeten, Hanne; Van Roy, Nadine; Vandesompele, Jo; Speleman, Frank; Philippé, Jan; Verhasselt, Bruno

2013-01-01

Chronic lymphocytic leukemia (CLL) is a disease with variable clinical outcome. Several prognostic factors such as the immunoglobulin heavy chain variable genes (IGHV) mutation status are linked to the B-cell receptor (BCR) complex, supporting a role for triggering the BCR in vivo in the pathogenesis. The miRNA profile upon stimulation and correlation with IGHV mutation status is however unknown. To evaluate the transcriptional response of peripheral blood CLL cells upon BCR stimulation in vitro, miRNA and mRNA expression was measured using hybridization arrays and qPCR. We found both IGHV mutated and unmutated CLL cells to respond with increased expression of MYC and other genes associated with BCR activation, and a phenotype of cell cycle progression. Genome-wide expression studies showed hsa-miR-132-3p/hsa-miR-212 miRNA cluster induction associated with a set of downregulated genes, enriched for genes modulated by BCR activation and amplified by Myc. We conclude that BCR triggering of CLL cells induces a transcriptional response of genes associated with BCR activation, enhanced cell cycle entry and progression and suggest that part of the transcriptional profiles linked to IGHV mutation status observed in isolated peripheral blood are not cell intrinsic but rather secondary to in vivo BCR stimulation. PMID:23560086

Relatively favorable outcome after allogeneic stem cell transplantation for BCR-ABL1-positive AML: A survey from the acute leukemia working party of the European Society for blood and marrow transplantation (EBMT).

PubMed

Lazarevic, Vladimir Lj; Labopin, Myriam; Depei, Wu; Yakoub-Agha, Ibrahim; Huynh, Anne; Ljungman, Per; Schaap, Nicolaas; Cornelissen, Jan J; Maillard, Natacha; Pioltelli, Pietro; Gedde-Dahl, Tobias; Lenhoff, Stig; Houhou, Mohamed; Esteve, Jordi; Mohty, Mohamad; Nagler, Arnon

2018-01-01

The aim of the study was to assess the role of allogeneic stem cell transplantation (SCT) in patients diagnosed with BCR-ABL1-positive acute myeloid leukemia (AML). Fifty-seven patients (median age, 48 years, range: 19-67) with BCR-ABL1 positive AML undergoing SCT were identified. The majority of the patients (70%) received a TKI before the transplant. At SCT 48 patients were in CR (45 in CR1), while 9 patients were transplanted in a more advanced stage of the disease. MRD was negative (BCR-ABL1/ABL < 10 4 ) at time of SCT in 36.1% (14/40). After SCT, 16 (61.5%) out of 26 patients with MRD positive at transplantation reached MRD negativity. After a median follow-up of 6.3 years (0.7-14.2), NRM, RI, LFS, OS, and GRFS at 5 years were 18.1%, 37%, 44.2%, 53.8%, and 32.1%, respectively. The cumulative incidence of acute GvHD grade II-IV was 16.4%, incidence of chronic GvHD 24.9%, and of extensive cGvHD 21.4%, respectively. In patients who received SCT in CR1, 5-yr NRM, RI, LFS, OS, and GRFS were 15.9%, 36.4%, 46.5%, 59.4%, and 34.9%, respectively. Univariate analysis showed that age (<50 vs. ≥50 years) was associated with RI (5-yr: 22.7 vs. 50%), LFS (5-yr: 61.9 vs. 31.8%), and GRFS (5-yr: 52.4 vs. 18.2%), whereas MRD-negative status before SCT was associated with an improved GRFS (38.9 vs. 16.7%). We conclude that the outcome of patients <50 years of age with BCR-ABL1-positive AML receiving allogeneic SCT in CR is relatively favorable, possibly reflecting the beneficial effect of the use of TKI. © 2017 Wiley Periodicals, Inc.

CALR, JAK2 and MPL mutation status in Argentinean patients with BCR-ABL1- negative myeloproliferative neoplasms.

PubMed

Ojeda, Mara Jorgelina; Bragós, Irma Margarita; Calvo, Karina Lucrecia; Williams, Gladis Marcela; Carbonell, María Magdalena; Pratti, Arianna Flavia

2018-05-01

To establish the frequency of JAK2, MPL and CALR mutations in Argentinean patients with BCR-ABL1-negative  myeloproliferative neoplasms (MPN) and to compare their clinical and haematological features. Mutations of JAK2V617F, JAK2 exon 12, MPL W515L/K and CALR were analysed in 439 Argentinean patients with BCR-ABL1-negative MPN, including 176 polycythemia vera (PV), 214 essential thrombocythemia (ET) and 49 primary myelofibrosis (PMF). In 94.9% of PV, 85.5% ET and 85.2% PMF, we found mutations in JAK2, MPL or CALR. 74.9% carried JAK2V617F, 12.3% CALR mutations, 2.1% MPL mutations and 10.7% were triple negative. In ET, nine types of CALR mutations were identified, four of which were novel. PMF patients were limited to types 1 and 2, type 2 being more frequent. In ET, patients with CALR mutation were younger and had higher platelet counts than those with JAK2V617F and triple negative. In addition, JAK2V617F patients had high leucocyte and haemoglobin values compared with CALR-mutated and triple-negative patients. In PMF, patients with mutant CALR were associated with higher platelet counts. Our study underscores the importance of JAK2, MPL and CALR genotyping for accurate diagnosis of patients with BCR-ABL1-negative MPN.

BCR-ABL fusion regions as a source of multiple leukemia-specific CD8+ T-cell epitopes.

PubMed

Kessler, J H; Bres-Vloemans, S A; van Veelen, P A; de Ru, A; Huijbers, I J G; Camps, M; Mulder, A; Offringa, R; Drijfhout, J W; Leeksma, O C; Ossendorp, F; Melief, C J M

2006-10-01

For immunotherapy of residual disease in patients with Philadelphia-positive leukemias, the BCR-ABL fusion regions are attractive disease-specific T-cell targets. We analyzed these regions for the prevalence of cytotoxic T lymphocyte (CTL) epitopes by an advanced reverse immunology procedure. Seventeen novel BCR-ABL fusion peptides were identified to bind efficiently to the human lymphocyte antigen (HLA)-A68, HLA-B51, HLA-B61 or HLA-Cw4 HLA class I molecules. Comprehensive enzymatic digestion analysis showed that 10 out of the 28 HLA class I binding fusion peptides were efficiently excised after their C-terminus by the proteasome, which is an essential requirement for efficient cell surface expression. Therefore, these peptides are prime vaccine candidates. The other peptides either completely lacked C-terminal liberation or were only inefficiently excised by the proteasome, rendering them inappropriate or less suitable for inclusion in a vaccine. CTL raised against the properly processed HLA-B61 epitope AEALQRPVA from the BCR-ABL e1a2 fusion region, expressed in acute lymphoblastic leukemia (ALL), specifically recognized ALL tumor cells, proving cell surface presentation of this epitope, its applicability for immunotherapy and underlining the accuracy of our epitope identification strategy. Our study provides a reliable basis for the selection of optimal peptides to be included in immunotherapeutic BCR-ABL vaccines against leukemia.

Droplet Digital PCR for BCR/ABL(P210) Detecting of CML: A High Sensitive Method of the Minimal Residual Disease& Disease Progression.

PubMed

Wang, Wen-Jun; Zheng, Chao-Feng; Liu, Zhuang; Tan, Yan-Hong; Chen, Xiu-Hua; Zhao, Bin-Liang; Li, Guo-Xia; Xu, Zhi-Fang; Ren, Fang-Gang; Zhang, Yao-Fang; Chang, Jian-Mei; Wang, Hong-Wei

2018-04-25

The present study intended to establish a droplet digital PCR (dd-PCR) for monitoring minimal residual disease (MRD) in patients with BCR/ABL (P210)-positive CML, thereby achieving deep-level monitoring of tumor load and determining the efficacy for guided clinically individualized treatment. Using dd-PCR and RT-qPCR, two cell suspensions were obtained from K562 cells and normal peripheral blood mononuclear cells by gradient dilution and were measured at the cellular level. At peripheral blood(PB) level, 61 cases with CML-chronic phase (CML-CP) were obtained after tyrosine kinase inhibitors (TKIs) treatment and regular follow-ups. By RT-qPCR, BCR/ABL (P210) fusion gene was undetectable in PB after three successive analyses, which were performed once every three months. At the same time, dd-PCR was performed simultaneously with the last equal amount of cDNA. Ten CML patients with MR4.5 were followed up by the two methods. At the cellular level, consistency of results of dd-PCR and RT-qPCR reached R 2 ≥0.99, with conversion equation of Y=33.148X 1.222 (Y: dd-PCR results; X: RT-qPCR results). In the dd-PCR test, 11 of the 61 CML patients (18.03%) tested positive and showed statistically significant difference (P<0.01). In the follow-up of 10 CML patients who were in MR4.5, 10 patients loss of MR4.0, and 4 were tested positive by dd-PCR 3 months earlier than by RT-qPCR. In contrast with RT-qPCR, dd-PCR is more sensitive, thus enabling accurate conversion of dd-PCR results into internationally standard RT-qPCR results by conversion equation, to achieve a deeper molecular biology-based stratification of BCR/ABL(P210) MRD. It has some reference value to monitor disease progression in clinic. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Vaccine Therapy in Reducing the Frequency of Cytomegalovirus Events in Patients With Hematologic Malignancies Undergoing Donor Stem Cell Transplant

ClinicalTrials.gov

2017-12-15

Accelerated Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Adult Acute Lymphoblastic Leukemia in Remission; Adult Acute Myeloid Leukemia in Remission; Adult Hodgkin Lymphoma; Adult Non-Hodgkin Lymphoma; Chronic Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Cytomegaloviral Infection; Hematopoietic and Lymphoid Cell Neoplasm; HLA-A*0201 Positive Cells Present; Myelodysplastic Syndrome; Adult Lymphoblastic Lymphoma; Chronic Lymphocytic Leukemia; Myelofibrosis; Myeloproliferative Neoplasm

Fludarabine Phosphate, Cyclophosphamide, Total Body Irradiation, and Donor Stem Cell Transplant in Treating Patients With Blood Cancer

ClinicalTrials.gov

2018-06-13

Accelerated Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Acute Leukemia in Remission; Acute Lymphoblastic Leukemia; Acute Myeloid Leukemia; Acute Myeloid Leukemia With FLT3/ITD Mutation; Acute Myeloid Leukemia With Gene Mutations; Aplastic Anemia; B-Cell Non-Hodgkin Lymphoma; CD40 Ligand Deficiency; Chronic Granulomatous Disease; Chronic Leukemia in Remission; Chronic Lymphocytic Leukemia; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Chronic Myelomonocytic Leukemia; Chronic Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Congenital Amegakaryocytic Thrombocytopenia; Congenital Neutropenia; Congenital Pure Red Cell Aplasia; Glanzmann Thrombasthenia; Immunodeficiency Syndrome; Myelodysplastic Syndrome; Myelofibrosis; Myeloproliferative Neoplasm; Paroxysmal Nocturnal Hemoglobinuria; Plasma Cell Myeloma; Polycythemia Vera; Recurrent Non-Hodgkin Lymphoma; Refractory Non-Hodgkin Lymphoma; Secondary Acute Myeloid Leukemia; Secondary Myelodysplastic Syndrome; Severe Aplastic Anemia; Shwachman-Diamond Syndrome; Sickle Cell Disease; T-Cell Non-Hodgkin Lymphoma; Thalassemia; Waldenstrom Macroglobulinemia; Wiskott-Aldrich Syndrome

Evaluation of deoxyhypusine synthase inhibitors targeting BCR-ABL positive leukemias.

PubMed

Ziegler, Patrick; Chahoud, Tuhama; Wilhelm, Thomas; Pällman, Nora; Braig, Melanie; Wiehle, Valeska; Ziegler, Susanne; Schröder, Marcus; Meier, Chris; Kolodzik, Adrian; Rarey, Matthias; Panse, Jens; Hauber, Joachim; Balabanov, Stefan; Brümmendorf, Tim H

2012-12-01

Effective inhibition of BCR-ABL tyrosine kinase activity with Imatinib represents a breakthrough in the treatment of patients with chronic myeloid leukemia (CML). However, more than 30 % of patients with CML in chronic phase do not respond adequately to Imatinib and the drug seems not to affect the quiescent pool of BCR-ABL positive leukemic stem and progenitor cells. Therefore, despite encouraging clinical results, Imatinib can still not be considered a curative treatment option in CML. We recently reported downregulation of eukaryotic initiation factor 5A (eIF5A) in Imatinib treated K562 cells. Furthermore, the inhibition of eIF5A by siRNA in combination with Imatinib has been shown to exert synergistic cytotoxic effects on BCR-ABL positive cell lines. Based on the structure of known deoxyhypusine synthase (DHS) inhibitors such as CNI-1493, a drug design approach was applied to develop potential compounds targeting DHS. Here we report the biological evaluation of selected novel (DHSI-15) as compared to established (CNI-1493, deoxyspergualin) DHS inhibitors. We show that upon the compounds tested, DHSI-15 and deoxyspergualin exert strongest antiproliferative effects on BCR-ABL cells including Imatinib resistant mutants. However, this effect did not seem to be restricted to BCR-ABL positive cell lines or primary cells. Both compounds are able to induce apoptosis/necrosis during long term incubation of BCR-ABL positive BA/F3 derivates. Pharmacological synergism can be observed for deoxyspergualin and Imatinib, but not for DHSI-15 and Imatinib. Finally we show that deoxyspergualin is able to inhibit proliferation of CD34+ progenitor cells from CML patients. We conclude that inhibition of deoxyhypusine synthase (DHS) can be supportive for the anti-proliferative treatment of leukemia and merits further investigation including other cancers.

BCR-ABL1 tyrosine kinase inhibitors for the treatment of chronic myeloid leukemia.

PubMed

Cuellar, Sandra; Vozniak, Michael; Rhodes, Jill; Forcello, Nicholas; Olszta, Daniel

2017-01-01

The management of chronic myeloid leukemia with BCR-ABL1 tyrosine kinase inhibitors has evolved chronic myeloid leukemia into a chronic, manageable disease. A patient-centered approach is important for the appropriate management of chronic myeloid leukemia and optimization of long-term treatment outcomes. The pharmacist plays a key role in treatment selection, monitoring drug-drug interactions, identification and management of adverse events, and educating patients on adherence. The combination of tyrosine kinase inhibitors with unique safety profiles and individual patients with unique medical histories can make managing treatment difficult. This review will provide up-to-date information regarding tyrosine kinase inhibitor-based treatment of patients with chronic myeloid leukemia. Management strategies for adverse events and considerations for drug-drug interactions will not only vary among patients but also across tyrosine kinase inhibitors. Drug-drug interactions can be mild to severe. In instances where co-administration of concomitant medications cannot be avoided, it is critical to understand how drug levels are impacted and how subsequent dose modifications ensure therapeutic drug levels are maintained. An important component of patient-centered management of chronic myeloid leukemia also includes educating patients on the significance of early and regular monitoring of therapeutic milestones, emphasizing the importance of adhering to treatment in achieving these targets, and appropriately modifying treatment if these clinical goals are not being met. Overall, staying apprised of current research, utilizing the close pharmacist-patient relationship, and having regular interactions with patients, will help achieve successful long-term treatment of chronic myeloid leukemia in the age of BCR-ABL1 tyrosine kinase inhibitors.

TIDEL-II: first-line use of imatinib in CML with early switch to nilotinib for failure to achieve time-dependent molecular targets

PubMed Central

Yeung, David T.; Osborn, Michael P.; White, Deborah L.; Branford, Susan; Braley, Jodi; Herschtal, Alan; Kornhauser, Michael; Issa, Samar; Hiwase, Devendra K.; Hertzberg, Mark; Schwarer, Anthony P.; Filshie, Robin; Arthur, Christopher K.; Kwan, Yiu Lam; Trotman, Judith; Forsyth, Cecily J.; Taper, John; Ross, David M.; Beresford, Jennifer; Tam, Constantine; Mills, Anthony K.; Grigg, Andrew P.

2015-01-01

The Therapeutic Intensification in De Novo Leukaemia (TIDEL)-II study enrolled 210 patients with chronic phase chronic myeloid leukemia (CML) in two equal, sequential cohorts. All started treatment with imatinib 600 mg/day. Imatinib plasma trough level was performed at day 22 and if <1000 ng/mL, imatinib 800 mg/day was given. Patients were then assessed against molecular targets: BCR-ABL1 ≤10%, ≤1%, and ≤0.1% at 3, 6, and 12 months, respectively. Cohort 1 patients failing any target escalated to imatinib 800 mg/day, and subsequently switched to nilotinib 400 mg twice daily for failing the same target 3 months later. Cohort 2 patients failing any target switched to nilotinib directly, as did patients with intolerance or loss of response in either cohort. At 2 years, 55% of patients remained on imatinib, and 30% on nilotinib. Only 12% were >10% BCR-ABL1 at 3 months. Confirmed major molecular response was achieved in 64% at 12 months and 73% at 24 months. MR4.5 (BCR-ABL1 ≤0.0032%) at 24 months was 34%. Overall survival was 96% and transformation-free survival was 95% at 3 years. This trial supports the feasibility and efficacy of an imatinib-based approach with selective, early switching to nilotinib. This trial was registered at www.anzctr.org.au as #12607000325404. PMID:25519749

Amplification of the BCR/ABL fusion gene clustered on a masked Philadelphia chromosome in a patient with myeloblastic crisis of chronic myelocytic leukemia.

PubMed

Gargallo, Patricia M; Cuello, Maria Teresa; Aranguren, Pedro Negri; Larripa, Irene B

2003-06-01

Although the chronic phase of chronic myelocytic leukemia (CML) is characterized by the Philadelphia (Ph) chromosome creating a hybrid BCR/ABL gene, additional genetic changes involved in blast crisis are poorly understood. We report a 4-8-fold amplification by tandem duplication of the BCR/ABL fusion gene clustered on a masked Ph chromosome in a 61-year-old male patient with CML in myeloblastic crisis. Our finding suggests that the BCR/ABL amplification may play a role as a novel mechanism in the progression to an aggressive blast transformation in some cases of Ph-positive CML.

Ovarian minimal residual disease in chronic myeloid leukaemia.

PubMed

Abir, Ronit; Aviram, Adina; Feinmesser, Meora; Stein, Jerry; Yaniv, Isaac; Parnes, Doris; Ben-Haroush, Avi; Meirow, Dror; Rabizadeh, Esther; Fisch, Benjamin

2014-02-01

The options for fertility preservation include cryopreservation of ovarian tissue. Although transplantation of cryopreserved-thawed ovarian tissue in cancer survivors has resulted in live births, there is evidence of malignancy involvement in ovarian tissue, especially in leukaemia. The objectives of this study were to investigate the involvement of chronic myeloid leukaemia (CML) in ovaries by both pathological/immunohistochemical methods and PCR for the identification of the Philadelphia chromosome (BCR-ABL transcripts). The patient was a survivor of paediatric CML whose ovaries were cryopreserved. The patient became infertile and requested ovarian reimplantation in adulthood. Pathological examinations of ovarian tissue with immunohistochemical stainings, quantitative PCR and two-step nested PCR were applied to identify BCR-ABL transcripts. Despite the lack of positive pathological/immunohistochemical evidence, PCR and two-step nested PCR revealed that the ovary was contaminated by malignant minimal residual CML. Survivors of childhood CML may harbour minimal residual disease in the ovaries. This finding stresses the danger of reseeding cancer by ovarian grafting, especially in patients with leukaemia. If ovarian grafting is considered, reimplantation should be preceded by examination of ovarian samples both pathologically and by molecular techniques. On the basis of molecular findings, ovarian autografting was not recommended in this case report. Copyright © 2013 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Targets of B-cell antigen receptor signaling: the phosphatidylinositol 3-kinase/Akt/glycogen synthase kinase-3 signaling pathway and the Rap1 GTPase.

PubMed

Gold, M R; Ingham, R J; McLeod, S J; Christian, S L; Scheid, M P; Duronio, V; Santos, L; Matsuuchi, L

2000-08-01

In this review, we discuss the role of phosphatidylinositol 3-kinase (PI3K) and Rap 1 in B-cell receptor (BCR) signaling. PI3K produces lipids that recruit pleckstrin homology domain-containing proteins to the plasma membrane. Akt is a kinase that the BCR activates in this manner. Akt phosphorylates several transcription factors as well as proteins that regulate apoptosis and protein synthesis. Akt also regulates glycogen synthase kinase-3, a kinase whose substrates include the nuclear factor of activated T cells (NF-AT)cl and beta-catenin transcriptional activators. In addition to Akt, PI3K-derived lipids also regulate the activity and localization of other targets of BCR signaling. Thus, a key event in BCR signaling is the recruitment of PI3K to the plasma membrane where its substrates are located. This is mediated by binding of the Src homology (SH) 2 domains in PI3K to phosphotyrosine-containing sequences on membrane-associated docking proteins. The docking proteins that the BCR uses to recruit PI3K include CD19, Cbl, Gab1, and perhaps Gab2. We have shown that Gab1 colocalizes PI3K with SH2 domain-containing inositol phosphatase (SHIP) and SHP2, two enzymes that regulate PI3K-dependent signaling. In contrast to PI3K, little is known about the Rap1 GTPase. We showed that the BCR activates Rap1 via phospholipase C-dependent production of diacylglycerol. Since Rap1 is thought to regulate cell adhesion and cell polarity, it may be involved in B-cell migration.

Erosion of the chronic myeloid leukaemia stem cell pool by PPARγ agonists.

PubMed

Prost, Stéphane; Relouzat, Francis; Spentchian, Marc; Ouzegdouh, Yasmine; Saliba, Joseph; Massonnet, Gérald; Beressi, Jean-Paul; Verhoeyen, Els; Raggueneau, Victoria; Maneglier, Benjamin; Castaigne, Sylvie; Chomienne, Christine; Chrétien, Stany; Rousselot, Philippe; Leboulch, Philippe

2015-09-17

Whether cancer is maintained by a small number of stem cells or is composed of proliferating cells with approximate phenotypic equivalency is a central question in cancer biology. In the stem cell hypothesis, relapse after treatment may occur by failure to eradicate cancer stem cells. Chronic myeloid leukaemia (CML) is quintessential to this hypothesis. CML is a myeloproliferative disorder that results from dysregulated tyrosine kinase activity of the fusion oncoprotein BCR-ABL. During the chronic phase, this sole genetic abnormality (chromosomal translocation Ph(+): t(9;22)(q34;q11)) at the stem cell level causes increased proliferation of myeloid cells without loss of their capacity to differentiate. Without treatment, most patients progress to the blast phase when additional oncogenic mutations result in a fatal acute leukaemia made of proliferating immature cells. Imatinib mesylate and other tyrosine kinase inhibitors (TKIs) that target the kinase activity of BCR-ABL have improved patient survival markedly. However, fewer than 10% of patients reach the stage of complete molecular response (CMR), defined as the point when BCR-ABL transcripts become undetectable in blood cells. Failure to reach CMR results from the inability of TKIs to eradicate quiescent CML leukaemia stem cells (LSCs). Here we show that the residual CML LSC pool can be gradually purged by the glitazones, antidiabetic drugs that are agonists of peroxisome proliferator-activated receptor-γ (PPARγ). We found that activation of PPARγ by the glitazones decreases expression of STAT5 and its downstream targets HIF2α and CITED2, which are key guardians of the quiescence and stemness of CML LSCs. When pioglitazone was given temporarily to three CML patients in chronic residual disease in spite of continuous treatment with imatinib, all of them achieved sustained CMR, up to 4.7 years after withdrawal of pioglitazone. This suggests that clinically relevant cancer eradication may become a generally attainable goal by combination therapy that erodes the cancer stem cell pool.

Viral/Nonviral Chimeric Nanoparticles to Synergistically Suppress Leukemia Proliferation via Simultaneous Gene Transduction and Silencing

PubMed Central

Hong, Cheol Am; Cho, Soo Kyung; Edson, Julius A.; Kim, Jane; Ingato, Dominique; Pham, Bryan; Chuang, Anthony; Fruman, David; Kwon, Young Jik

2017-01-01

Single modal cancer therapy that targets one pathological pathway often turns out to be inefficient. For example, relapse of Chronic Myelogenous Leukemia (CML) after inhibiting BCR-ABL fusion protein using tyrosine kinase inhibitors (TKI) (e.g., Imatinib) is of significant clinical concern. This study developed a dual modal gene therapy that simultaneously tackles two key BCR-ABL-linked pathways using viral/nonviral chimeric nanoparticles (ChNPs). Consisting of an adeno-associated virus (AAV) core and an acid-degradable polymeric shell, the ChNPs were designed to simultaneously induce pro-apoptotic BIM expression by the AAV core and silence pro-survival MCL-1 by the small interfering RNA (siRNA) encapsulated in the shell. The resulting BIM/MCL-1 ChNPs were able to efficiently suppress the proliferation of BCR-ABL+ K562 and FL5.12/p190 cells in vitro and in vivo via simultaneously expressing BIM and silencing MCL-1. Interestingly, the synergistic anti-leukemic effects generated by BIM/MCL-1 ChNPs were specific to BCR-ABL+ cells and independent of a proliferative cytokine, IL-3. The AAV core of ChNPs was efficiently shielded from inactivation by anti-AAV serum and avoided the generation of anti-AAV serum, without acute toxicity. This study demonstrates the development of a synergistically efficient, specific, and safe therapy for leukemia using gene carriers that simultaneously manipulate multiple and inter-linked pathological pathways. PMID:27472284

Influence of BCR/ABL fusion proteins on the course of Ph leukemias.

PubMed

Telegeev, Gennady D; Dubrovska, Anna N; Dybkov, Mykhaylo V; Maliuta, Stanislav S

2004-01-01

The hallmark of chronic myeloid leukemia (CML) and a subset of acute lymphoblastic leukemia (ALL) is the presence of the Philadelphia chromosome as a result of the t(9;22) translocation. This gene rearrangement results in the production of a novel oncoprotein, BCR/ABL, a constitutively active tyrosine kinase. There is compelling evidence that the malignant transformation by BCR/ABL is critically dependent on its Abl tyrosine kinase activity. Also the bcr part of the hybrid gene takes part in realization of the malignant phenotype. We supposed that additional mutations accumulate in this region of the BCR/ABL oncogene during the development of the malignant blast crisis in CML patients. In ALL patients having p210 fusion protein the mutations were supposed to be preexisting. Sequencing of PCR product of the BCR/ABL gene (Dbl, PH region) showed that along with single-nucleotide substitutions other mutations, mostly deletions, had occurred. In an ALL patient a deletion of the 5th exon was detected. The size of the deletions varied from 36 to 220 amino acids. For one case of blast crisis of CML changes in the character of actin organization were observed. Taking into account the functional role of these domains in the cell an etiological role of such mutations on the disease phenotype and leukemia progression is plausible.

Nontranscriptional regulation of SYK by the coactivator OCA-B is required at multiple stages of B cell development.

PubMed

Siegel, Rachael; Kim, Unkyu; Patke, Alina; Yu, Xin; Ren, Xiaodi; Tarakhovsky, Alexander; Roeder, Robert G

2006-05-19

OCA-B was originally identified as a nuclear transcriptional coactivator that is essential for antigen-driven immune responses. The later identification of a membrane bound, myristoylated form of OCA-B suggested additional, unique functions in B cell signaling pathways. This study has shown that OCA-B also functions in the pre-B1-to-pre-B2 cell transition and, most surprisingly, that it directly interacts with SYK, a tyrosine kinase critical for pre-BCR and BCR signaling. This unprecedented type of interaction-a transcriptional coactivator with a signaling kinase-occurs in the cytoplasm and directly regulates SYK stability. This study indicates that OCA-B is required for pre-BCR and BCR signaling at multiple stages of B cell development through its nontranscriptional regulation of SYK. Combined with the deregulation of OCA-B target genes, this may help explain the multitude of defects observed in B cell development and immune responses of Oca-b-/- mice.

Computational dissection of allosteric inhibition of the SH2 domain of Bcr-Abl kinase by the monobody inhibitor AS25.

PubMed

Ji, Mingfei; Zheng, Guodong; Li, Xiaolong; Zhang, Zhongqin; Jv, Guanqun; Wang, Xiaowei; Wang, Jialin

2017-06-01

The deregulated breakpoint cluster region (Bcr)-Abelson tyrosine kinase (Abl) fusion protein represents an attractive pharmacological target for the treatment of chronic myeloid leukemia (CML). The high affinity of monobody AS25 was designed to target the Src homology 2 (SH2) domain of Bcr-Abl, leading to allosteric inhibition of Bcr-Abl through formation of protein-protein interactions. An I164E mutation in the SH2 domain disrupts AS25 binding to the SH2 domain of Bcr-Abl. The detailed mechanisms, however, remain to be unresolved. Here, molecular dynamics (MD) simulations and binding free energy calculations were performed to explore the conformational and energetic differences between the wild-type (WT) complexes of Bcr-Abl SH2 domain and AS25 (SH2 WT -AS25) as well as the mutated complexes (SH2 I164E -AS25). The results revealed that I164E mutation not only caused an increase in the conformational flexibility of SH2-AS25 complexes, but also weakened the binding affinity of AS25 to SH2. The comparative binding modes of SH2-AS25 complexes between WT and the I164E mutant were comprehensively analyzed to unravel the disruption of hydrophobic and hydrogen bonding interactions in the interface of the SH2-AS25 complex triggered by the I164E mutation. The results obtained may help to design the next generation of higher affinity Bcr-Abl SH2-specific peptide inhibitors.

BCR mediated signal transduction in immature and mature B cells.

PubMed

Koncz, Gábor; Bodor, Csaba; Kövesdi, Dorottya; Gáti, Róbert; Sármay, Gabriella

2002-06-03

Ligation of B cell receptors (BCR) on immature B cells may induce apoptosis, while in mature B cells it stimulates cell activation and growth. The signaling pathway regulating the differential functional response, death or survival of the B cell is not fully characterized. We have tested the intracellular signaling requirement of these processes using B cells isolated from the spleen of irradiated auto-reconstituted (transitional immature B cells) and untreated mice (mature B cells), respectively. We compared the BCR induced intracellular [Ca2+] transient, protein tyrosine phosphorylation and ERK phosphorylation, furthermore, the activation of Elk-1 and CREB transcription factors. The BCR induced rise of intracellular [Ca2+] did not significantly differ in the two populations, only a slight difference in the late phase of the response was observed. Immature B cells responded with a maximum tyrosine phosphorylation to a five times lower dose of anti-IgM compared to the mature population. Most importantly, we have found a significant difference in the tyrosine phosphorylation of the Gab family adaptor proteins, Gab1/2. In contrast to mature B cells, crosslinking of BCR on immature B cells did not induce tyrosine phosphorylation of Gab2, thus the Gab2-organized signal amplification complex could not be produced. Furthermore, we detected a significant difference in the kinetics of BCR induced ERK, Elk-1 and CREB phosphorylation. In immature B cells, ERK was transiently phosphorylated, ceasing after 120 min, while in mature cells, ERK phosphorylation was sustained. Elk-1 and CREB activation was also transient in immature B cells, followed the kinetics of ERK phosphorylation. The lack of sustained Erk1/2 activation suppresses the transcription factors necessary for the proliferation signal. Since ERK is regulated by the phosphorylated Gab1/2, these data demonstrate that BCR triggered phosphorylation and signal amplification of Gab1/2 is a critical step in a life or death decision of B cells.

Comprehensive review of JAK inhibitors in myeloproliferative neoplasms

PubMed Central

Sonbol, Mohamad Bassam; Firwana, Belal; Zarzour, Ahmad; Morad, Mohammad; Rana, Vishal

2013-01-01

Myeloproliferative neoplasms (MPNs) are clonal hematopoietic stem-cell disorders, characterized phenotypically by the abnormal accumulation of mature-appearing myeloid cells. Polycythemia vera, essential thrombocythemia, primary myelofibrosis (also known as ‘BCR-ABL1-negative’ MPNs), and chronic myeloid leukemia (CML) are the primary types of MPNs. After the discovery of the BCR-ABL1 fusion protein in CML, several oncogenic tyrosine kinases have been identified in ‘BCR-ABL1-negative’ MPNs, most importantly, JAK2V617F mutation. The similarity in the clinical characteristics of the BCR-ABL1-negative MPN patients along with the prevalence of the Janus kinase mutation in this patient population provided a strong rationale for the development of a new class of pharmacologic inhibitors that target this pathway. The first of its class, ruxolitinib, has now been approved by the food and drug administration (FDA) for the management of patients with intermediate- to high-risk myelofibrosis. Ruxolitinib provides significant and sustained improvements in spleen related and constitutional symptoms secondary to the disease. Although noncurative, ruxolitinib represents a milestone in the treatment of myelofibrosis patients. Other types of JAK2 inhibitors are being tested in various clinical trials at this point and may provide better efficacy data and safety profile than its predecessor. In this article, we comprehensively reviewed and summarized the available preclinical and clinical trials pertaining to JAK inhibitors. PMID:23610611

Outcomes with frontline nilotinib treatment in Turkish patients with newly diagnosed Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase.

PubMed

Saydam, Guray; Haznedaroglu, Ibrahim C; Kaynar, Leylagul; Yavuz, Akif S; Ali, Ridvan; Guvenc, Birol; Akay, Olga M; Baslar, Zafer; Ozbek, Ugur; Sonmez, Mehmet; Aydin, Demet; Pehlivan, Mustafa; Undar, Bulent; Dagdas, Simten; Ayyildiz, Orhan; Akkaynak, Diyar Z; Akin, Gulnur; İlhan, Osman

2018-02-27

Nilotinib is a BCR-ABL1 tyrosine kinase inhibitor approved for the treatment of patients with chronic myeloid leukemia in chronic phase (CML-CP). This study was the first prospective evaluation of the efficacy and safety of nilotinib in Turkish patients with newly diagnosed CML-CP. The primary endpoint of the study was the rate of major molecular response (MMR; BCR-ABL1 ≤ 0.1% on the International Scale [BCR-ABL1 IS ]) by 12 months. Patients with newly diagnosed CML-CP were treated with nilotinib 300 mg twice daily. This analysis was based on the first 12 months of follow-up in a 24-month study. This study is registered with ClinicalTrials.gov (NCT01274351). Of 112 patients enrolled, 66.1% (80% CI, 59.7-72.0%) achieved MMR and 22.3% achieved a deep molecular response of MR 4.5 (BCR-ABL1 IS ≤0.0032%) by 12 months. During the first year of treatment, one patient progressed to blast crisis and two patients died. Safety results were consistent with previous studies. Most adverse events (AEs) were grade 1/2. Most frequently reported nonhematologic AEs of any grade were elevations in bilirubin, alanine aminotransferase, and triglycerides. These results support the use of nilotinib 300 mg twice daily as a standard-of-care treatment option for patients with newly diagnosed CML-CP with low and intermediate risk.

BCR ligation induced by IgM stimulation results in gene expression and functional changes only in IgV H unmutated chronic lymphocytic leukemia (CLL) cells.

PubMed

Guarini, Anna; Chiaretti, Sabina; Tavolaro, Simona; Maggio, Roberta; Peragine, Nadia; Citarella, Franca; Ricciardi, Maria Rosaria; Santangelo, Simona; Marinelli, Marilisa; De Propris, Maria Stefania; Messina, Monica; Mauro, Francesca Romana; Del Giudice, Ilaria; Foà, Robert

2008-08-01

Chronic lymphocytic leukemia (CLL) patients exhibit a variable clinical course. To investigate the association between clinicobiologic features and responsiveness of CLL cells to anti-IgM stimulation, we evaluated gene expression changes and modifications in cell-cycle distribution, proliferation, and apoptosis of IgV(H) mutated (M) and unmutated (UM) samples upon BCR cross-linking. Unsupervised analysis highlighted a different response profile to BCR stimulation between UM and M samples. Supervised analysis identified several genes modulated exclusively in the UM cases upon BCR cross-linking. Functional gene groups, including signal transduction, transcription, cell-cycle regulation, and cytoskeleton organization, were up-regulated upon stimulation in UM cases. Cell-cycle and proliferation analyses confirmed that IgM cross-linking induced a significant progression into the G(1) phase and a moderate increase of proliferative activity exclusively in UM patients. Moreover, we observed only a small reduction in the percentage of subG(0/1) cells, without changes in apoptosis, in UM cases; contrariwise, a significant increase of apoptotic levels was observed in stimulated cells from M cases. These results document that a differential genotypic and functional response to BCR ligation between IgV(H) M and UM cases is operational in CLL, indicating that response to antigenic stimulation plays a pivotal role in disease progression.

Elucidating the Role of cAbl and the Abi-Family of cAbl Target Proteins in Cancer Development and Progression

DTIC Science & Technology

1999-07-01

patients with Ph’-positive leukemias also revealed loss of Abi proteins. We determined by RNase protection assay and reverse transcriptase polymerase...myelogenous leukemia . Abi protein levels also appeared unaltered by Western blot analysis of human lung, liver, colon, and breast carcinoma tissues as...generated in the presence of Bcr-Abl • Abi protein degradation was observed in Ph’+ leukemia -derived cells, but not in Ph1- leukemias or in human breast

Potentiation of antileukemic therapies by the dual PI3K/PDK-1 inhibitor, BAG956: effects on BCR-ABL– and mutant FLT3-expressing cells

PubMed Central

Weisberg, Ellen; Banerji, Lolita; Wright, Renee D.; Barrett, Rosemary; Ray, Arghya; Moreno, Daisy; Catley, Laurence; Jiang, Jingrui; Hall-Meyers, Elizabeth; Sauveur-Michel, Maira; Stone, Richard; Galinsky, Ilene; Fox, Edward; Kung, Andrew L.

2008-01-01

Mediators of PI3K/AKT signaling have been implicated in chronic myeloid leukemia (CML) and acute myeloid leukemia (AML). Studies have shown that inhibitors of PI3K/AKT signaling, such as wortmannin and LY294002, are able to inhibit CML and AML cell proliferation and synergize with targeted tyrosine kinase inhi-bitors. We investigated the ability of BAG956, a dual PI3K/PDK-1 inhibitor, to be used in combination with inhibitors of BCR-ABL and mutant FLT3, as well as with the mTOR inhibitor, rapamycin, and the rapamycin derivative, RAD001. BAG956 was shown to block AKT phosphorylation induced by BCR-ABL–, and induce apoptosis of BCR-ABL–expressing cell lines and patient bone marrow cells at concentrations that also inhibit PI3K signaling. Enhancement of the inhibitory effects of the tyrosine kinase inhibitors, imatinib and nilotinib, by BAG956 was demonstrated against BCR-ABL expressing cells both in vitro and in vivo. We have also shown that BAG956 is effective against mutant FLT3-expressing cell lines and AML patient bone marrow cells. Enhancement of the inhibitory effects of the tyrosine kinase inhibitor, PKC412, by BAG956 was demonstrated against mutant FLT3-expressing cells. Finally, BAG956 and rapamycin/RAD001 were shown to combine in a nonantagonistic fashion against BCR-ABL– and mutant FLT3-expressing cells both in vitro and in vivo. PMID:18184863

Therapy of chronic myeloid leukemia: twilight of the imatinib era?

PubMed

Trela, Ewelina; Glowacki, Sylwester; Błasiak, Janusz

2014-01-01

Chronic myeloid leukemia (CML) results from the clonal expansion of pluripotent hematopoietic stem cells containing the active BCR/ABL fusion gene produced by a reciprocal translocation of the ABL1 gene to the BCR gene. The BCR/ABL protein displays a constitutive tyrosine kinase activity and confers on leukemic cells growth and proliferation advantage and resistance to apoptosis. Introduction of imatinib (IM) and other tyrosine kinase inhibitors (TKIs) has radically improved the outcome of patients with CML and some other diseases with BCR/ABL expression. However, a fraction of CML patients presents with resistance to this drug. Regardless of clinical profits of IM, there are several drawbacks associated with its use, including lack of eradication of the malignant clone and increasing relapse rate resulting from long-term therapy, resistance, and intolerance. Second and third generations of TKIs have been developed to break IM resistance. Clinical studies revealed that the introduction of second-generation TKIs has improved the overall survival of CML patients; however, some with specific mutations such as T315I remain resistant. Second-generation TKIs may completely replace imatinib in perspective CML therapy, and addition of third-generation inhibitors may overcome resistance induced by every form of point mutations.

Antagonism of SET using OP449 enhances the efficacy of tyrosine kinase inhibitors and overcome drug resistance in myeloid leukemia

PubMed Central

Agarwal, Anupriya; MacKenzie, Ryan J.; Pippa, Raffaella; Eide, Christopher A.; Oddo, Jessica; Tyner, Jeffrey W.; Sears, Rosalie; Vitek, Michael P.; Odero, María D.; Christensen, Dale; Druker, Brian J.

2014-01-01

Purpose The SET oncoprotein, a potent inhibitor of the protein phosphatase 2A (PP2A), is overexpressed in leukemia. We evaluated the efficacy of SET antagonism in chronic myeloid leukemia (CML) and acute myeloid leukemia (AML) cell lines, a murine leukemia model, and primary patient samples using OP449, a specific, cell-penetrating peptide that antagonizes SET's inhibition of PP2A. Experimental Design In vitro cytotoxicity and specificity of OP449 in CML and AML cell lines and primary samples were measured using proliferation, apoptosis and colonogenic assays. Efficacy of target inhibition by OP449 is evaluated by immunoblotting and PP2A assay. In vivo antitumor efficacy of OP449 was measured in human HL-60 xenografted murine model. Results We observed that OP449 inhibited growth of CML cells including those from patients with blastic phase disease and patients harboring highly drug-resistant BCR-ABL1 mutations. Combined treatment with OP449 and ABL1 tyrosine kinase inhibitors was significantly more cytotoxic to K562 cells and primary CD34+ CML cells. SET protein levels remained unchanged with OP449 treatment, but BCR-ABL1-mediated downstream signaling was significantly inhibited with the degradation of key signaling molecules such as BCR-ABL1, STAT5, and AKT. Similarly, AML cell lines and primary patient samples with various genetic lesions showed inhibition of cell growth after treatment with OP449 alone or in combination with respective kinase inhibitors. Finally, OP449 reduced the tumor burden of mice xenografted with human leukemia cells. Conclusions We demonstrate a novel therapeutic paradigm of SET antagonism using OP449 in combination with tyrosine kinase inhibitors for the treatment of CML and AML. PMID:24436473

Germline mutations in ABL1 cause an autosomal dominant syndrome characterized by congenital heart defects and skeletal malformations.

PubMed

Wang, Xia; Charng, Wu-Lin; Chen, Chun-An; Rosenfeld, Jill A; Al Shamsi, Aisha; Al-Gazali, Lihadh; McGuire, Marianne; Mew, Nicholas Ah; Arnold, Georgianne L; Qu, Chunjing; Ding, Yan; Muzny, Donna M; Gibbs, Richard A; Eng, Christine M; Walkiewicz, Magdalena; Xia, Fan; Plon, Sharon E; Lupski, James R; Schaaf, Christian P; Yang, Yaping

2017-04-01

ABL1 is a proto-oncogene well known as part of the fusion gene BCR-ABL1 in the Philadelphia chromosome of leukemia cancer cells. Inherited germline ABL1 changes have not been associated with genetic disorders. Here we report ABL1 germline variants cosegregating with an autosomal dominant disorder characterized by congenital heart disease, skeletal abnormalities, and failure to thrive. The variant c.734A>G (p.Tyr245Cys) was found to occur de novo or cosegregate with disease in five individuals (families 1-3). Additionally, a de novo c.1066G>A (p.Ala356Thr) variant was identified in a sixth individual (family 4). We overexpressed the mutant constructs in HEK 293T cells and observed increased tyrosine phosphorylation, suggesting increased ABL1 kinase activities associated with both the p.Tyr245Cys and p.Ala356Thr substitutions. Our clinical and experimental findings, together with previously reported teratogenic effects of selective BCR-ABL inhibitors in humans and developmental defects in Abl1 knockout mice, suggest that ABL1 has an important role during organismal development.

Identification of novel tyrosine kinase inhibitors for drug resistant T315I mutant BCR-ABL: a virtual screening and molecular dynamics simulations study

NASA Astrophysics Data System (ADS)

Banavath, Hemanth Naick; Sharma, Om Prakash; Kumar, Muthuvel Suresh; Baskaran, R.

2014-11-01

BCR-ABL tyrosine kinase plays a major role in the pathogenesis of chronic myeloid leukemia (CML) and is a proven target for drug development. Currently available drugs in the market are effective against CML; however, side-effects and drug-resistant mutations in BCR-ABL limit their full potential. Using high throughput virtual screening approach, we have screened several small molecule databases and docked against wild-type and drug resistant T315I mutant BCR-ABL. Drugs that are currently available, such as imatinib and ponatinib, were also docked against BCR-ABL protein to set a cutoff value for our screening. Selected lead compounds were further evaluated for chemical reactivity employing density functional theory approach, all selected ligands shows HLG value > 0.09900 and the binding free energy between protein-ligand complex interactions obtained was rescored using MM-GBSA. The selected compounds showed least ΔG score -71.53 KJ/mol to maximum -126.71 KJ/mol in both wild type and drug resistant T315I mutant BCR-ABL. Following which, the stability of the docking complexes were evaluated by molecular dynamics simulation (MD) using GROMACS4.5.5. Results uncovered seven lead molecules, designated with Drug-Bank and PubChem ids as DB07107, DB06977, ST013616, DB04200, ST007180 ST019342, and DB01172, which shows docking scores higher than imatinib and ponatinib.

Development of a rapid and sensitive one-step reverse transcription-nested polymerase chain reaction in a single tube using the droplet-polymerase chain reaction machine.

PubMed

Yamaguchi, Akemi; Matsuda, Kazuyuki; Sueki, Akane; Taira, Chiaki; Uehara, Masayuki; Saito, Yasunori; Honda, Takayuki

2015-08-25

Reverse transcription (RT)-nested polymerase chain reaction (PCR) is a time-consuming procedure because it has several handling steps and is associated with the risk of cross-contamination during each step. Therefore, a rapid and sensitive one-step RT-nested PCR was developed that could be performed in a single tube using a droplet-PCR machine. The K562 BCR-ABL mRNA-positive cell line as well as bone marrow aspirates from 5 patients with chronic myelogenous leukemia (CML) and 5 controls without CML were used. We evaluated one-step RT-nested PCR using the droplet-PCR machine. One-step RT-nested PCR performed in a single tube using the droplet-PCR machine enabled the detection of BCR-ABL mRNA within 40min, which was 10(3)-fold superior to conventional RT nested PCR using three steps in separate tubes. The sensitivity of the one-step RT-nested PCR was 0.001%, with sample reactivity comparable to that of the conventional assay. One-step RT-nested PCR was developed using the droplet-PCR machine, which enabled all reactions to be performed in a single tube accurately and rapidly and with high sensitivity. This one-step RT-nested PCR may be applicable to a wide spectrum of genetic tests in clinical laboratories. Copyright © 2015 Elsevier B.V. All rights reserved.

Expression, prognostic significance and mutational analysis of protein tyrosine phosphatase SHP-1 in chronic myeloid leukemia.

PubMed

Papadopoulou, Vasiliki; Kontandreopoulou, Elina; Panayiotidis, Panayiotis; Roumelioti, Maria; Angelopoulou, Maria; Kyriazopoulou, Lydia; Diamantopoulos, Panagiotis T; Vaiopoulos, George; Variami, Eleni; Kotsianidis, Ioannis; Athina Viniou, Nora

2016-05-01

The protein tyrosine phosphatase SHP-1 dephosphorylates BCR-ABL1, thereby serving as a potential control mechanism of BCR-ABL1 kinase activity. Pathways regulating SHP-1 expression, which could be exploited in the therapeutics of TKI-resistant chronic myeloid leukemia (CML), remain unknown. Moreover, the questions of whether there is any kind of SHP-1 deregulation in CML, contributing to disease initiation or evolution, as well as the question of prognostic significance of SHP-1, have not been definitively answered. This study shows moderately lower SHP-1 mRNA expression in chronic phase CML patients in comparison to healthy individuals and no change in SHP-1 mRNA levels after successful TKI treatment. Mutational analysis of the aminoterminal and phosphatase domains of SHP-1 in patients did not reveal genetic lesions. This study also found no correlation of SHP-1 expression at diagnosis with response to treatment, although a trend for lower SHP-1 expression was noted in the very small non-responders' group of the 3-month therapeutic milestone.

Allium Roseum L. Extract Exerts Potent Suppressive Activities on Chronic Myeloid Leukemia K562 Cell Viability Through the Inhibition of BCR-ABL, PI3K/Akt, and ERK1/2 Pathways and the Abrogation of VEGF Secretion.

PubMed

Souid, Soumaya; Najjaa, Hanen; Riahi-Chebbi, Ichrak; Haoues, Meriam; Neffati, Mohamed; Arnault, Ingrid; Auger, Jacques; Karoui, Habib; Essafi, Makram; Essafi-Benkhadir, Khadija

2017-01-01

Use of plant extracts, alone or combined to the current chemotherapy as chemosensitizers, has emerged as a promising strategy to overcome tumor drug resistance. Here, we investigated the anticancer activity of Allium roseum L. extracts, a wild edible species in North Africa, on human Chronic Myeloid Leukemia (CML) K562 cells. The dehydrated aqueous extract (DAE) disturbed the cell cycle progression and induced the apoptosis of K562 cells. Chemical analysis of DAE showed a diversity of organosulfur compounds S-alk(en)yl-cysteine sulfoxides (RCSO) and high amount of allicin, suggesting that such molecule may be behind its antitumor effect. DAE was efficient in inhibiting K562 cell viability. DAE inhibitory effect was associated with the dephosphorylation of the BCR-ABL kinase and interfered with ERK 1/2 , Akt, and STAT5 pathways. Furthermore, we found that DAE-induced inactivation of Akt kinase led to the activation of its target FOXO3 transcription factor, enhancing the expression of FOXO3-regulated proapoptotic effectors, Bim and Bax, and cell cycle inhibitor p27. Finally, we found that DAE reduced the secretion of vascular endothelial growth factor. Overall, our data suggest that A. roseum extract has great potential as a nontoxic cheap and effective alternative to conventional chemotherapy.

Developmental Regulation of an Adhesin Gene during Cellular Morphogenesis in the Fungal Pathogen Candida albicans▿ †

PubMed Central

Argimón, Silvia; Wishart, Jill A.; Leng, Roger; Macaskill, Susan; Mavor, Abigail; Alexandris, Thomas; Nicholls, Susan; Knight, Andrew W.; Enjalbert, Brice; Walmsley, Richard; Odds, Frank C.; Gow, Neil A. R.; Brown, Alistair J. P.

2007-01-01

Candida albicans expresses specific virulence traits that promote disease establishment and progression. These traits include morphological transitions between yeast and hyphal growth forms that are thought to contribute to dissemination and invasion and cell surface adhesins that promote attachment to the host. Here, we describe the regulation of the adhesin gene ALS3, which is expressed specifically during hyphal development in C. albicans. Using a combination of reporter constructs and regulatory mutants, we show that this regulation is mediated by multiple factors at the transcriptional level. The analysis of ALS3 promoter deletions revealed that this promoter contains two activation regions: one is essential for activation during hyphal development, while the second increases the amplitude of this activation. Further deletion analyses using the Renilla reniformis luciferase reporter delineate the essential activation region between positions −471 and −321 of the promoter. Further 5′ or 3′ deletions block activation. ALS3 transcription is repressed mainly by Nrg1 and Tup1, but Rfg1 contributes to this repression. Efg1, Tec1, and Bcr1 are essential for the transcriptional activation of ALS3, with Tec1 mediating its effects indirectly through Bcr1 rather than through the putative Tec1 sites in the ALS3 promoter. ALS3 transcription is not affected by Cph2, but Cph1 contributes to full ALS3 activation. The data suggest that multiple morphogenetic signaling pathways operate through the promoter of this adhesin gene to mediate its developmental regulation in this major fungal pathogen. PMID:17277173

Coupling a universal DNA circuit with graphene sheets/polyaniline/AuNPs nanocomposites for the detection of BCR/ABL fusion gene.

PubMed

Chen, Xueping; Wang, Li; Sheng, Shangchun; Wang, Teng; Yang, Juan; Xie, Guoming; Feng, Wenli

2015-08-19

This article described a novel method by coupling a universal DNA circuit with graphene sheets/polyaniline/AuNPs nanocomposites (GS/PANI/AuNPs) for highly sensitive and specific detection of BCR/ABL fusion gene (bcr/abl) in chronic myeloid leukemia (CML). DNA circuit known as catalyzed hairpin assembly (CHA) is enzyme-free and can be simply operated to achieve exponential amplification, which has been widely employed in biosensing. However, application of CHA has been hindered by the need of specially redesigned sequences for each single-stranded DNA input. Herein, a transducer hairpin (HP) was designed to obtain a universal DNA circuit with favorable signal-to-background ratio. To further improve signal amplification, GS/PANI/AuNPs with excellent conductivity and enlarged effective area were introduced into this DNA circuit. Consequently, by combining the advantages of CHA and GS/PANI/AuNPs, bcr/abl could be detected in a linear range from 10 pM to 20 nM with a detection limit of 1.05 pM. Moreover, this protocol showed excellent specificity, good stability and was successfully applied for the detection of real sample, which demonstrated its great potential in clinical application. Copyright © 2015 Elsevier B.V. All rights reserved.

The Prevalence of JAK2, MPL, and CALR Mutations in Chinese Patients With BCR-ABL1-Negative Myeloproliferative Neoplasms.

PubMed

Lin, Yani; Liu, Enbin; Sun, Qi; Ma, Jiao; Li, QingHua; Cao, Zeng; Wang, Jun; Jia, Yujiao; Zhang, Hongju; Song, Zhen; Ai, Xiaofei; Shi, Lihui; Feng, Xiaofang; Li, Chenwei; Wang, Jianxiang; Ru, Kun

2015-07-01

To evaluate the mutation frequency of JAK2 V617F, JAK2 exon 12, MPL exon 10, and CALR exon 9 and the value of the combined tests in the diagnosis of BCR-ABL1-negative myeloproliferative neoplasms (MPNs). In the current study, mutations of JAK2 V617F, JAK2 exon 12, MPL exon 10, and CALR exon 9 were analyzed in 929 Chinese patients with BCR-ABL1-negative MPN, including 234 cases of polycythemia vera (PV), 428 ETs, 187 PMFs, and 80 unclassifiable MPNs (MPN-Us). Our result showed that the positive rate of any of four mutations in patients with PV, ET, PMF, and MPN-U was 89.3%, 83.4%, 87.2%, and 77.5%, respectively, which significantly improved the diagnostic rate, especially in ET and PMF. Meanwhile, we also found that the patients without any of four mutations were younger than those with one or more mutations. Unexpectedly, the coexistence of JAK2 V617F and CALR exon 9 was identified in six (0.6%) patients, and JAK2 V617F and MPL exon 10 were present simultaneously in two (0.2%) patients. In addition, we also identified several novel mutation types in CALR exon 9. The combined genetic tests of JAK2 V617F, JAK2 exon 12, MPL exon 10, and CALR exon 9 help improve the diagnostic rate for BCR-ABL1-negative MPN. Copyright© by the American Society for Clinical Pathology.

Chronic Myeloid Leukemia in the Era of Tyrosine Kinase Inhibitors: An Evolving Paradigm of Molecularly Targeted Therapy.

PubMed

Ali, Mohamed A M

2016-08-01

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm, characterized by the unrestrained expansion of pluripotent hematopoietic stem cells. CML was the first malignancy in which a unique chromosomal abnormality was identified and a pathophysiologic association was suggested. The hallmark of CML is a reciprocal chromosomal translocation between the long arms of chromosomes 9 and 22, t(9; 22)(q34; q11), creating a derivative 9q+ and a shortened 22q-. The latter, known as the Philadelphia (Ph) chromosome, harbors the breakpoint cluster region-abelson (BCR-ABL) fusion gene, encoding the constitutively active BCR-ABL tyrosine kinase that is necessary and sufficient for initiating CML. The successful implementation of tyrosine kinase inhibitors (TKIs) for the treatment of CML remains a flagship for molecularly targeted therapy in cancer. TKIs have changed the clinical course of CML; however, some patients nonetheless demonstrate primary or secondary resistance to such therapy and require an alternative therapeutic strategy. Therefore, the assessment of early response to treatment with TKIs has become an important tool in the clinical monitoring of CML patients. Although mutations in the BCR-ABL have proven to be the most prominent mechanism of resistance to TKIs, other mechanisms-either rendering the leukemic cells still dependent on BCR-ABL activity or supporting oncogenic properties of the leukemic cells independent of BCR-ABL signaling-have been identified. This article provides an overview of the current understanding of CML pathogenesis; recommendations for diagnostic tools, treatment strategies, and management guidelines; and highlights the BCR-ABL-dependent and -independent mechanisms that contribute to the development of resistance to TKIs.

BCR/ABL downregulates DNA-PK(CS)-dependent and upregulates backup non-homologous end joining in leukemic cells.

PubMed

Poplawski, Tomasz; Blasiak, Janusz

2010-06-01

Non-homologous end joining (NHEJ) and homologous recombination repair (HRR) are the main mechanisms involved in the processing of DNA double strand breaks (DSBs) in humans. We showed previously that the oncogenic tyrosine kinase BCR/ABL stimulated DSBs repair by HRR. To evaluate the role of BCR/ABL in DSBs repair by NHEJ we examined the ability of leukemic BCR/ABL-expressing cell line BV173 to repair DNA damage induced by two DNA topoisomerase II inhibitors: etoposide and sobuzoxane. DNA lesions induced by sobuzoxane are repaired by a NHEJ pathway which is dependent on the catalytic subunit of protein kinase dependent on DNA (DNA-PK(CS); D-NHEJ), whereas damage evoked by etoposide are repaired by two distinct NHEJ pathways, dependent on or independent of DNA-PK(CS) (backup NHEJ, B-NHEJ). Cells incubated with STI571, a highly specific inhibitor of BCR/ABL, displayed resistance to these agents associated with an accelerated kinetics of DSBs repair, as measured by the neutral comet assay and pulsed field gel electrophoresis. However, in a functional NHEJ assay, cells preincubated with STI571 repaired DSBs induced by a restriction enzyme with a lower efficacy than without the preincubation and addition of wortmannin, a specific inhibitor of DNA-PK(CS), did not change efficacy of the NHEJ reaction. We suggest that BCR/ABL switch on B-NHEJ which is more error-prone then D-NHEJ and in such manner contribute to the increase of the genomic instability of leukemic cells.

Successful treatment of a chronic-phase T-315I-mutated chronic myelogenous leukemia patient with a combination of imatinib and interferon-alfa.

PubMed

Itonaga, Hidehiro; Tsushima, Hideki; Hata, Tomoko; Matsuo, Emi; Imanishi, Daisuke; Imaizumi, Yoshitaka; Kawaguchi, Yasuhisa; Fukushima, Takuya; Doi, Yuko; Mori, Sayaka; Kamihira, Shimeru; Tomonaga, Masao; Miyazaki, Yasushi

2012-02-01

The T315I BCR-ABL mutation in chronic myelogenous leukemia (CML) patients is responsible for up to 20% of all clinically observed resistance. This mutation confers resistance not only to imatinib, but also to second-generation BCR-ABL tyrosine kinases, such as nilotinib and dasatinib. A number of strategies have been implemented to overcome this resistance, but allogeneic stem cell transplantation remains the only established therapeutic option for a cure. A 61-year-old male was diagnosed with Philadelphia chromosome-positive chronic-phase CML in 2002. He was initially treated with imatinib and complete cytogenetic response (CCyR) was achieved 12 months later. However, after 18 months, a loss of CCyR was observed and a molecular study at 24 months revealed a T315I mutation of the BCR-ABL gene. At 30 months, imatinib/interferon-alfa (IFNα) combination therapy was initiated in an effort to overcome the resistance. Thirty months later, he re-achieved CCyR, and the T315I BCR-ABL mutation disappeared at 51 months. To our knowledge, this is the first case report showing the effectiveness of imatinib/IFNα combination therapy for CML patients bearing the T315I BCR-ABL mutation.

Combined inhibition of β-catenin and Bcr-Abl synergistically targets tyrosine kinase inhibitor-resistant blast crisis chronic myeloid leukemia blasts and progenitors in vitro and in vivo.

PubMed

Zhou, H; Mak, P Y; Mu, H; Mak, D H; Zeng, Z; Cortes, J; Liu, Q; Andreeff, M; Carter, B Z

2017-10-01

Tyrosine kinase inhibitor (TKI) resistance and progression to blast crisis (BC), both related to persistent β-catenin activation, remain formidable challenges for chronic myeloid leukemia (CML). We observed overexpression of β-catenin in BC-CML stem/progenitor cells, particularly in granulocyte-macrophage progenitors, and highest among a novel CD34 + CD38 + CD123 hi Tim-3 hi subset as determined by CyTOF analysis. Co-culture with mesenchymal stromal cells (MSCs) induced the expression of β-catenin and its target CD44 in CML cells. A novel Wnt/β-catenin signaling modulator, C82, and nilotinib synergistically killed KBM5 T315I and TKI-resistant primary BC-CML cells with or without BCR-ABL kinase mutations even under leukemia/MSC co-culture conditions. Silencing of β-catenin by short interfering RNA restored sensitivity of primary BCR-ABL T315I/E255V BC-CML cells to nilotinib. Combining the C82 pro-drug, PRI-724, with nilotinib significantly prolonged the survival of NOD/SCID/IL2Rγ null mice injected with primary BCR-ABL T315I/E255V BC-CML cells. The combined treatment selectively targeted CML progenitors and inhibited CD44, c-Myc, survivin, p-CRKL and p-STAT5 expression. In addition, pretreating primary BC-CML cells with C82, or the combination, but not with nilotinib alone, significantly impaired their engraftment potential in NOD/SCID/IL2Rγ-null-3/GM/SF mice and significantly prolonged survival. Our data suggest potential benefit of concomitant β-catenin and Bcr-Abl inhibition to prevent or overcome Bcr-Abl kinase-dependent or -independent TKI resistance in BC-CML.

Structural Mechanism of the Pan-BCR-ABL Inhibitor Ponatinib (AP24534): Lessons for Overcoming Kinase Inhibitor Resistance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Tianjun; Commodore, Lois; Huang, Wei-Sheng

2012-01-20

The BCR-ABL inhibitor imatinib has revolutionized the treatment of chronic myeloid leukemia. However, drug resistance caused by kinase domain mutations has necessitated the development of new mutation-resistant inhibitors, most recently against the T315I gatekeeper residue mutation. Ponatinib (AP24534) inhibits both native and mutant BCR-ABL, including T315I, acting as a pan-BCR-ABL inhibitor. Here, we undertook a combined crystallographic and structure-activity relationship analysis on ponatinib to understand this unique profile. While the ethynyl linker is a key inhibitor functionality that interacts with the gatekeeper, virtually all other components of ponatinib play an essential role in its T315I inhibitory activity. The extensive networkmore » of optimized molecular contacts found in the DFG-out binding mode leads to high potency and renders binding less susceptible to disruption by single point mutations. The inhibitory mechanism exemplified by ponatinib may have broad relevance to designing inhibitors against other kinases with mutated gatekeeper residues.« less

Targeting HSP90 dimerization via the C-terminus is effective in imatinib resistant CML and lacks heat shock response.

PubMed

Bhatia, Sanil; Diedrich, Daniela; Frieg, Benedikt; Ahlert, Heinz; Stein, Stefan; Bopp, Bertan; Lang, Franziska; Zang, Tao; Kröger, Tobias; Ernst, Thomas; Kögler, Gesine; Krieg, Andreas; Lüdeke, Steffen; Kunkel, Hana; Rodrigues Moita, Ana J; Kassack, Matthias U; Marquardt, Viktoria; Opitz, Friederike V; Oldenburg, Marina; Remke, Marc; Babor, Florian; Grez, Manuel; Hochhaus, Andreas; Borkhardt, Arndt; Groth, Georg; Nagel-Steger, Luitgard; Jose, Joachim; Kurz, Thomas; Gohlke, Holger; Hansen, Finn K; Hauer, Julia

2018-05-03

Heat shock protein 90 (HSP90) stabilizes many client proteins including BCR-ABL1 oncoprotein. BCR-ABL1 is the hallmark of CML in which treatment-free remission (TFR) is limited with clinical and economic consequences. Thus, there is an urgent need for novel therapeutics, which synergize with current treatment approaches. Several inhibitors targeting the N-terminal domain (NTD) of HSP90 are under investigation; however, side effects such as induction of heat shock response (HSR) and toxicity have so far precluded their FDA approval. We have developed a novel inhibitor (referred to as aminoxyrone) of HSP90 function by targeting HSP90 dimerization via the C-terminal domain (CTD). This was achieved by structure-based molecular design, chemical synthesis, and functional pre-clinical in vitro and in vivo validation using CML cell lines and patient-derived CML cells. Aminoxyrone (AX) is a promising potential candidate, which induces apoptosis in leukemic stem cells (LSCs) fraction (CD34 + CD38 - ) as well as the leukemic bulk (CD34 + CD38 + ) of primary CML and in TKI-resistant cells. Furthermore, BCR-ABL1 oncoprotein and related pro-oncogenic cellular responses are downregulated and targeting HSP90 C-terminus by AX does not induce HSR in vitro and in vivo. We also probed the potential of AX in other therapy refractory leukemia such as BCR-ABL1+ BCP-ALL, FLT3-ITD+ AML and Ph-like BCP-ALL. Therefore, AX is the first peptidometic C-terminal HSP90 inhibitor with the potential to increase TFR in TKI sensitive and refractory CML patients and also offers a novel therapeutic option for patients with other therapy-refractory leukemia, due to its low toxicity profile and lack of HSR. Copyright © 2018 American Society of Hematology.

A rare case of a three way complex variant positive Philadelphia translocation involving chromosome (9;11;22)(q34;p15;q11) in chronic myeloid leukemia: A case report

PubMed Central

Asif, Muhammad; Hussain, Abrar; Rasool, Mahmood

2016-01-01

The t(9;22)(q34;q11) translocation is present in 90–95% of patients with chronic myeloid leukemia (CML). Variant complex translocations have been observed in 5–8% of CML patients, in which a third chromosome other than (9;22) is involved. Imatinib mesylate is the first line breakpoint cluster region-Abelson gene (BCR/ABL)-targeted oral therapy for CML, and may produce a complete response in 70–80% of CML patients in the chronic phase. In the present study, a bone marrow sample was used for conventional cytogenetic analysis, and the fluorescence in situ hybridization (FISH) test was used for BCR/ABL gene detection. A hematological analysis was also performed to determine the white blood cell (WBC) count, red blood cell count, hemoglobin levels, packed and mean cell volumes, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration and platelet values of the patient. The hematological analysis of the patient indicated the increased WBC of 186.5×103 cells/µl, and decreased hemoglobin levels of 11.1 g/dl. The FISH test revealed that 67% cells demonstrated BCR/ABL gene translocation. The patient was treated with 400 mg imatinib mesylate daily, and was monitored at various intervals over a 6-month period. The present study reports the rare case of a patient that demonstrates a three-way Philadelphia chromosome-positive translocation involving 46XY,t(9;11;22)(q34;p15;q11)[10], alongside CML in the chronic phase. The translocation was analyzed using cytogenetic and FISH tests. PMID:27602125

Use of deferasirox, an iron chelator, to overcome imatinib resistance of chronic myeloid leukemia cells.

PubMed

Kim, Dae Sik; Na, Yoo Jin; Kang, Myoung Hee; Yoon, Soo-Young; Choi, Chul Won

2016-03-01

The treatment of chronic myeloid leukemia (CML) has achieved impressive success since the development of the Bcr-Abl tyrosine kinase inhibitor, imatinib mesylate. Nevertheless, resistance to imatinib has been observed, and a substantial number of patients need alternative treatment strategies. We have evaluated the effects of deferasirox, an orally active iron chelator, and imatinib on K562 and KU812 human CML cell lines. Imatinib-resistant CML cell lines were created by exposing cells to gradually increasing concentrations of imatinib. Co-treatment of cells with deferasirox and imatinib induced a synergistic dose-dependent inhibition of proliferation of both CML cell lines. Cell cycle analysis showed an accumulation of cells in the subG1 phase. Western blot analysis of apoptotic proteins showed that co-treatment with deferasirox and imatinib induced an increased expression of apoptotic proteins. These tendencies were clearly identified in imatinib-resistant CML cell lines. The results also showed that co-treatment with deferasirox and imatinib reduced the expression of BcrAbl, phosphorylated Bcr-Abl, nuclear factor-κB (NF-κB) and β-catenin. We observed synergistic effects of deferasirox and imatinib on both imatinib-resistant and imatinib-sensitive cell lines. These effects were due to induction of apoptosis and cell cycle arrest by down-regulated expression of NF-κB and β-catenin levels. Based on these results, we suggest that a combination treatment of deferasirox and imatinib could be considered as an alternative treatment option for imatinib-resistant CML.

Reduced tyrosine kinase inhibitor dose is predicted to be as effective as standard dose in chronic myeloid leukemia: A simulation study based on phase 3 trial data.

PubMed

Fassoni, Artur C; Baldow, Christoph; Roeder, Ingo; Glauche, Ingmar

2018-06-28

Continuing tyrosine kinase inhibitor mediated targeting of the BCR-ABL1 oncoprotein is the standard therapy for chronic myeloid leukemia and allows for a sustained disease control in the majority of patients. While therapy cessation for patients appeared as a safe option for about half of the optimally responding patients, a systematic assessment of long-term tyrosine kinase inhibitor dose de-escalation is missing. We use a mathematical model to analyze and consistently describe biphasic treatment responses from tyrosine kinase inhibitor treated patients from two independent clinical phase-3 trials. Scale estimates reveal that drug efficiency determines the initial response while the long-term behavior is limited by the rare activation of leukemic stem cells. We use this mathematical framework to investigate the influence of different dosing regimens on the treatment outcome. We provide strong evidence suggesting that tyrosine kinase inhibitor dose de-escalation (at least 50%) does not lead to a reduction of long-term treatment efficiency for most patients, which have already achieved sustained remission, and maintains the secondary decline of BCR-ABL1 levels. We demonstrate that continuous BCR-ABL1 monitoring provides patient-specific predictions of an optimal reduced dose not decreasing the anti-leukemic effect on residual leukemic stem cells. Our results are consistent with the interim results of the DESTINY trial and provide clinically testable predictions. Our results suggest that dose halving should be considered as a long-term treatment option for well-responding chronic myeloid leukemia patients under continuing maintenance therapy with tyrosine kinase inhibitors. We emphasize the clinical potential of this approach to reduce treatment-related side-effects and therapy costs. Copyright © 2018, Ferrata Storti Foundation.

An aberrant NOTCH2-BCR signaling axis in B cells from patients with chronic GVHD.

PubMed

Poe, Jonathan C; Jia, Wei; Su, Hsuan; Anand, Sarah; Rose, Jeremy J; Tata, Prasanthi V; Suthers, Amy N; Jones, Corbin D; Kuan, Pei Fen; Vincent, Benjamin G; Serody, Jonathan S; Horwitz, Mitchell E; Ho, Vincent T; Pavletic, Steven Z; Hakim, Frances T; Owzar, Kouros; Zhang, Dadong; Blazar, Bruce R; Siebel, Christian W; Chao, Nelson J; Maillard, Ivan; Sarantopoulos, Stefanie

2017-11-09

B-cell receptor (BCR)-activated B cells contribute to pathogenesis in chronic graft-versus-host disease (cGVHD), a condition manifested by both B-cell autoreactivity and immune deficiency. We hypothesized that constitutive BCR activation precluded functional B-cell maturation in cGVHD. To address this, we examined BCR-NOTCH2 synergy because NOTCH has been shown to increase BCR responsiveness in normal mouse B cells. We conducted ex vivo activation and signaling assays of 30 primary samples from hematopoietic stem cell transplantation patients with and without cGVHD. Consistent with a molecular link between pathways, we found that BCR-NOTCH activation significantly increased the proximal BCR adapter protein BLNK. BCR-NOTCH activation also enabled persistent NOTCH2 surface expression, suggesting a positive feedback loop. Specific NOTCH2 blockade eliminated NOTCH-BCR activation and significantly altered NOTCH downstream targets and B-cell maturation/effector molecules. Examination of the molecular underpinnings of this "NOTCH2-BCR axis" in cGVHD revealed imbalanced expression of the transcription factors IRF4 and IRF8 , each critical to B-cell differentiation and fate. All- trans retinoic acid (ATRA) increased IRF4 expression, restored the IRF4 -to- IRF8 ratio, abrogated BCR-NOTCH hyperactivation, and reduced NOTCH2 expression in cGVHD B cells without compromising viability. ATRA-treated cGVHD B cells had elevated TLR9 and PAX5 , but not BLIMP1 (a gene-expression pattern associated with mature follicular B cells) and also attained increased cytosine guanine dinucleotide responsiveness. Together, we reveal a mechanistic link between NOTCH2 activation and robust BCR responses to otherwise suboptimal amounts of surrogate antigen. Our findings suggest that peripheral B cells in cGVHD patients can be pharmacologically directed from hyperactivation toward maturity.

Genetic characterization of plasmid-associated triphenylmethane reductase in Listeria monocytogenes.

PubMed

Dutta, Vikrant; Elhanafi, Driss; Osborne, Jason; Martinez, Mira Rakic; Kathariou, Sophia

2014-09-01

The enzyme triphenylmethane reductase (TMR) reduces toxic triphenylmethane dyes into colorless, nontoxic derivatives, and TMR-producing microorganisms have been proposed as bioremediation tools. Analysis of the genome of Listeria monocytogenes H7858 (1998-1999 hot dog outbreak) revealed that the plasmid (pLM80) of this strain harboring a gene cassette (bcrABC) conferring resistance to benzalkonium chloride (BC) and other quaternary ammonium disinfectants also harbored a gene (tmr) highly homologous to TMR-encoding genes from diverse Gram-negative bacteria. The pLM80-associated tmr was located two genes downstream of bcrABC as part of a putative IS1216 composite transposon. To confirm the role of tmr in triphenylmethane dye detoxification, we introduced various tmr-harboring fragments of pLM80 in a pLM80-cured derivative of strain H7550, from the same outbreak as H7858, and assessed the resistance of the constructs to the triphenylmethane dyes crystal violet (CV) and malachite green. Transcriptional and subcloning data suggest that the regulation of TMR is complex. Constructs harboring fragments spanning bcrABC and tmr were CV resistant, and in such constructs tmr transcription was induced by sublethal levels of either BC or CV. However, constructs harboring only tmr and its upstream intergenic region could also confer resistance to CV, albeit at lower levels. Screening a panel of BC-resistant L. monocytogenes strains revealed that all those harboring bcrABC and adjacent pLM80 sequences, including tmr, were resistant to CV and decolorized this dye. The findings suggest a potential role of TMR as a previously unknown adaptive attribute for environmental persistence of L. monocytogenes. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Durable treatment-free remission in patients with chronic myeloid leukemia in chronic phase following frontline nilotinib: 96-week update of the ENESTfreedom study.

PubMed

Ross, David M; Masszi, Tamas; Gómez Casares, María Teresa; Hellmann, Andrzej; Stentoft, Jesper; Conneally, Eibhlin; Garcia-Gutierrez, Valentin; Gattermann, Norbert; le Coutre, Philipp D; Martino, Bruno; Saussele, Susanne; Giles, Francis J; Radich, Jerald P; Saglio, Giuseppe; Deng, Weiping; Krunic, Nancy; Bédoucha, Véronique; Gopalakrishna, Prashanth; Hochhaus, Andreas

2018-05-01

ENESTfreedom is evaluating treatment-free remission (TFR) following frontline nilotinib in patients with chronic myeloid leukemia (CML) in chronic phase. Following our primary analysis at 48 weeks, we here provide an updated 96-week analysis. Attempting TFR required ≥ 3 years of nilotinib, a molecular response of MR 4.5 [BCR-ABL1 ≤ 0.0032% on the International Scale (BCR-ABL1 IS )], and sustained deep molecular response (DMR) during a 1-year consolidation phase. Patients restarted nilotinib following loss of major molecular response (MMR; BCR-ABL1 IS  ≤ 0.1%). Ninety-six weeks after stopping treatment (3.6-year median prior nilotinib duration), 93 of 190 patients (48.9%) remained in TFR. Of 88 patients who restarted nilotinib following loss of MMR, 87 regained MMR and 81 regained MR 4.5 by the data cut-off. Ninety-six-week TFR rates were 61.3, 50.0, and 28.6% in patients with low, intermediate, and high Sokal risk scores at diagnosis, respectively. Patients consistently in MR 4.5 during consolidation had higher TFR rates (50.6%) than patients with ≥ 1 assessment without MR 4.5 during consolidation (35.0%). In a landmark analysis, 96-week TFR rates for patients with MR 4.5 , MR 4 (BCR-ABL1 IS  ≤ 0.01%) but not MR 4.5 , and MMR but not MR 4 at TFR week 12 were 82.6, 23.1, and 0%, respectively. There were no reports of disease progression or death due to CML; overall adverse event frequency decreased following TFR. Within the follow-up period, TFR did not adversely affect disease outcomes. These results demonstrate the feasibility and durability of TFR following frontline nilotinib and emphasize the importance of sustained DMR for TFR.

Disappearance of Bone Marrow Fibrosis in a Patient with Chronic Myeloid Leukemia Treated with Dasatinib.

PubMed

Vigna, Ernesto; Martino, Bruno; Bacci, Francesco; Recchia, Anna Grazia; Mendicino, Francesco; Morelli, Rosellina; Mauro, Francesca Romana; Musolino, Caterina; Greco, Rosa; Lucia, Eugenio; Sabattini, Elena; Morabito, Fortunato; Gentile, Massimo

2017-01-01

We report a case of a chronic myeloid leukemia patient showing progressive bone marrow fibrosis and anemia during imatinib therapy. Given the loss of major molecular response, we switched treatment to dasatinib 100 mg daily, observing a reduction in BCR-ABL transcript, a significant improvement of anemia, and a gradual disappearance of fibrosis. After 7 years of dasatinib therapy the patient maintains a complete cytogenetic response and a deep molecular response; the last bone biopsy confirmed the absence of fibrosis. © 2017 S. Karger AG, Basel.

BCR-ABL1 mutation development during first-line treatment with dasatinib or imatinib for chronic myeloid leukemia in chronic phase.

PubMed

Hughes, T P; Saglio, G; Quintás-Cardama, A; Mauro, M J; Kim, D-W; Lipton, J H; Bradley-Garelik, M B; Ukropec, J; Hochhaus, A

2015-09-01

BCR-ABL1 mutations are a common, well-characterized mechanism of resistance to imatinib as first-line treatment of chronic myeloid leukemia in chronic phase (CML-CP). Less is known about mutation development during first-line treatment with dasatinib and nilotinib, despite increased use because of higher response rates compared with imatinib. Retrospective analyses were conducted to characterize mutation development in patients with newly diagnosed CML-CP treated with dasatinib (n=259) or imatinib (n=260) in DASISION (Dasatinib versus Imatinib Study in Treatment-Naive CML-CP), with 3-year minimum follow-up. Mutation screening, including patients who discontinued treatment and patients who had a clinically relevant on-treatment event (no confirmed complete cytogenetic response (cCCyR) and no major molecular response (MMR) within 12 months; fivefold increase in BCR-ABL1 with loss of MMR; loss of CCyR), yielded a small number of patients with mutations (dasatinib, n=17; imatinib, n=18). Dasatinib patients had a narrower spectrum of mutations (4 vs 12 sites for dasatinib vs imatinib), fewer phosphate-binding loop mutations (1 vs 9 mutations), fewer multiple mutations (1 vs 6 patients) and greater occurrence of T315I (11 vs 0 patients). This trial was registered at www.clinicaltrials.gov as NCT00481247.

BCR-crosslinking induces a transcription of protein phosphatase component G5PR that is required for mature B-cell survival

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huq Ronny, Faisal Mahmudul; Igarashi, Hideya; Core Research for Evolutional Science and Technology

2006-02-03

BCR-crosslinking triggers activation-induced cell death (AICD) selectively in the restricted stage of B-cell differentiation. We examined the transcription of a protein phosphatase subunit G5PR in immature and mature B-cells, because absence of this factor augmented cell sensitivity to AICD, associated with increased activation of JNK and Bim. BCR-crosslinking-induced G5pr transcription in AICD-resistant mature splenic IgM{sup lo}IgD{sup hi} B-cells but not in AICD susceptible immature IgM{sup hi}IgD{sup lo} B-cells. Thus, G5pr induction correlated with the prevention of AICD; High in mature splenic CD23{sup hi} B-cells but low in immature B-cells of neonatal mice, sub-lethally irradiated mice, or xid mice. Lack ofmore » G5pr upregulation was associated with the prolonged activation of JNK. The G5pr cDNA transfection protected an immature B-cell line WEHI-231 from BCR-mediated AICD. The differential expression of G5PR might be responsible for the antigen-dependent selection of B-cells.« less

Chemopreventive Effects of Dietary Eicosapentaenoic Acid Supplementation in Experimental Myeloid Leukemia.

PubMed

Finch, Emily R; Kudva, Avinash K; Quickel, Michael D; Goodfield, Laura L; Kennett, Mary J; Whelan, Jay; Paulson, Robert F; Prabhu, K Sandeep

2015-10-01

Current therapies for treatment of myeloid leukemia do not eliminate leukemia stem cells (LSC), leading to disease relapse. In this study, we supplemented mice with eicosapentaenoic acid (EPA, C20:5), a polyunsaturated omega-3 fatty acid, at pharmacologic levels, to examine whether the endogenous metabolite, cyclopentenone prostaglandin delta-12 PGJ3 (Δ(12)-PGJ3), was effective in targeting LSCs in experimental leukemia. EPA supplementation for 8 weeks resulted in enhanced endogenous production of Δ(12)-PGJ3 that was blocked by indomethacin, a cyclooxygenase (COX) inhibitor. Using a murine model of chronic myelogenous leukemia (CML) induced by bone marrow transplantation of BCR-ABL-expressing hematopoietic stem cells, mice supplemented with EPA showed a decrease in the LSC population, and reduced splenomegaly and leukocytosis, when compared with mice on an oleic acid diet. Supplementation of CML mice carrying the T315I mutation (in BCR-ABL) with EPA resulted in a similar effect. Indomethacin blocked the EPA effect and increased the severity of BCR-ABL-induced CML and decreased apoptosis. Δ(12)-PGJ3 rescued indomethacin-treated BCR-ABL mice and decreased LSCs. Inhibition of hematopoietic-prostaglandin D synthase (H-PGDS) by HQL-79 in EPA-supplemented CML mice also blocked the effect of EPA. In addition, EPA supplementation was effective in a murine model of acute myeloid leukemia. EPA-supplemented mice exhibited a decrease in leukemia burden and a decrease in the LSC colony-forming unit (LSC-CFU). The decrease in LSCs was confirmed through serial transplantation assays in all disease models. The results support a chemopreventive role for EPA in myeloid leukemia, which is dependent on the ability to efficiently convert EPA to endogenous COX-derived prostanoids, including Δ(12)-PGJ3. ©2015 American Association for Cancer Research.

Attomolar electrochemical detection of the BCR/ABL fusion gene based on an amplifying self-signal metal nanoparticle-conducting polymer hybrid composite.

PubMed

Avelino, Karen Y P S; Frias, Isaac A M; Lucena-Silva, Norma; Gomes, Renan G; de Melo, Celso P; Oliveira, Maria D L; Andrade, César A S

2016-12-01

In the last ten years, conjugated polymers started to be used in the immobilization of nucleic acids via non-covalent interactions. In the present study, we describe the construction and use of an electrochemical DNA biosensor based on a nanostructured polyaniline-gold composite, specifically developed for the detection of the BCR/ABL chimeric oncogene. This chromosome translocation is used as a biomarker to confirm the clinical diagnosis of both chronic myelogenous leukemia (CML) and acute lymphocytic leukemia (ALL). The working principle of the biosensor rests on measuring the conductivity resulting from the non-covalent interactions between the hybrid nanocomposite and the DNA probe. The nanostructured platform exhibits a large surface area that enhances the conductivity. Positive cases, which result from the hybridization between DNA probe and targeted gene, induce changes in the amperometric current and in the charge transfer resistance (R CT ) responses. Atomic force microscopy (AFM) images showed changes in the genosensor surface after exposure to cDNA sample of patient with leukemia, evidencing the hybridization process. This new hybrid sensing-platform displayed high specificity and selectivity, and its detection limit is estimated to be as low as 69.4 aM. The biosensor showed excellent analytical performance for the detection of the BCR/ABL oncogene in clinical samples of patients with leukemia. Hence, this electrochemical sensor appears as a simple and attractive tool for the molecular diagnosis of the BCR/ABL oncogene even in early-stage cases of leukemia and for the monitoring of minimum levels of residual disease. Copyright © 2016 Elsevier B.V. All rights reserved.

Coexistence of chronic myelogenous leukemia and multiple myeloma. Case report and review of the literature.

PubMed

Tanaka, M; Kimura, R; Matsutani, A; Zaitsu, K; Oka, Y; Oizumi, K

1998-01-01

A case report of simultaneous presentation of chronic myelogenous leukemia (CML) and multiple myeloma (MM) in a 72-year-old female is described. Our case was typical of Ph1-positive and chimeric bcr-abl messenger RNA-positive CML. Furthermore, a marked IgG (kappa-type) paraproteinemia was present. Fluorescence in situ hybridization showed that 97% of marrow nucleated cells were positive for bcr-abl fusion signal, when myeloma cells in the bone marrow amounted to 19.0%. In the literature survey, 4 similar cases with coexistence of CML and MM have been identified.

Hsp90 N- and C-terminal double inhibition synergistically suppresses Bcr-Abl-positive human leukemia cells

PubMed Central

Chen, Xianling; Chen, Xiaole; Li, Ding; Fan, Yingjuan; Xu, Jianhua; Chen, Yuanzhong; Wu, Lixian

2017-01-01

Heat shock protein 90 (Hsp90) contains amino (N)–terminal domain, carboxyl(C)-terminal domain, and middle domains, which activate Hsp90 chaperone function cooperatively in tumor cells. One terminal occupancy might influence another terminal binding with inhibitor. The Bcr-Abl kinase is one of the Hsp90 clients implicated in the pathogenesis of chronic myeloid leukemia (CML). Present studies demonstrate that double inhibition of the N- and C-terminal termini can disrupt Hsp90 chaperone function synergistically, but not antagonistically, in Bcr-Abl-positive human leukemia cells. Furthermore, both the N-terminal inhibitor 17-AAG and the C-terminal inhibitor cisplatin (CP) have the capacity to suppress progenitor cells; however, only CP is able to inhibit leukemia stem cells (LSCs) significantly, which implies that the combinational treatment is able to suppress human leukemia in different mature states. PMID:28036294

Tyrosine phosphorylation of 3BP2 is indispensable for the interaction with VAV3 in chicken DT40 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chihara, Kazuyasu; Organization for Life Science Advancement Programs, University of Fukui, Fukui 910-1193; Kimura, Yukihiro

Adaptor protein c-Abl SH3 domain-binding protein-2 (3BP2) is known to play regulatory roles in immunoreceptor-mediated signal transduction. We have previously demonstrated that Tyr{sup 174}, Tyr{sup 183} and Tyr{sup 446} in mouse 3BP2 are predominantly phosphorylated by Syk, and the phosphorylation of Tyr{sup 183} and the Src homology 2 (SH2) domain of mouse 3BP2 are critical for B cell receptor (BCR)-induced activation of nuclear factor of activated T cells (NFAT) in human B cells. In this report, we have shown that Syk, but not Abl family protein-tyrosine kinases, is critical for BCR-mediated tyrosine phosphorylation of 3BP2 in chicken DT40 cells. Mutationalmore » analysis showed that Tyr{sup 174}, Tyr{sup 183} and Tyr{sup 426} of chicken 3BP2 are the major phosphorylation sites by Syk and the SH2 domain of 3BP2 is critical for tyrosine phosphorylation. In addition, phosphorylation of Tyr{sup 426} is required for the inducible interaction with the SH2 domain of Vav3. Moreover, the expression of the mutant form of 3BP2 in which Tyr{sup 426} was substituted to Phe resulted in the reduction in BCR-mediated Rac1 activation, when compared with the case of wild-type. Altogether, these data suggest that 3BP2 is involved in the activation of Rac1 through the regulation of Vav3 by Syk-dependent phosphorylation of Tyr{sup 426} following BCR stimulation. - Highlights: • 3BP2 is phosphorylated by Syk, but not Abl family kinases in BCR signaling. • Tyr183 and Tyr426 in chicken 3BP2 are the major phosphorylation sites by Syk. • The SH2 domain of 3BP2 is critical for tyrosine phosphorylation of 3BP2. • Phosphorylation of Tyr426 in 3BP2 is required for the inducible binding with Vav3. • 3BP2 is involved in the regulation of BCR-mediated Rac1 activation.« less

Dynamic pre-BCR homodimers fine-tune autonomous survival signals in B cell precursor acute lymphoblastic leukemia

PubMed Central

Erasmus, M. Frank; Matlawska-Wasowska, Ksenia; Kinjyo, Ichiko; Mahajan, Avanika; Winter, Stuart S.; Xu, Li; Horowitz, Michael; Lidke, Diane S.; Wilson, Bridget S.

2017-01-01

The pre-B cell receptor (pre-BCR) is an immature form of the BCR critical for early B lymphocyte development. It is composed of the membrane-bound immunoglobulin (Ig) heavy chain, surrogate light chain components, and the signaling subunits Igα and Igβ. We developed monovalent Quantum Dot (QD)-labeled probes specific for Igβ to study the behavior of pre-BCRs engaged in autonomous, ligand-independent signaling in live B cells. Single-particle tracking revealed that QD-labeled pre-BCRs engaged in transient, but frequent, homotypic interactions. Receptor motion was correlated at short separation distances, consistent with the formation of dimers and higher-order oligomers. Repeated encounters between diffusing pre-BCRs appeared to reflect transient co-confinement in plasma membrane domains. In human B cell precursor acute lymphoblastic leukemia (BCP-ALL) cells, we showed that frequent, short-lived, homotypic pre-BCR interactions stimulated survival signals, including expression of BCL6, which encodes a transcriptional repressor. These survival signals were blocked by inhibitory monovalent antigen-binding antibody fragments (Fabs) specific for the surrogate light chain components of the pre-BCR or by inhibitors of the tyrosine kinases Lyn and Syk. For comparison, we evaluated pre-BCR aggregation mediated by dimeric galectin-1, which has binding sites for carbohydrate and for the λ5 component of the surrogate light chain. Galectin-1 binding resulted in the formation of large, highly immobile pre-BCR aggregates, which was partially relieved by the addition of lactose to prevent the crosslinking of galectin-BCR complexes to other glycosylated membrane components. Analysis of the pre-BCR and its signaling partners suggested that they could be potential targets for combination therapy in BCP-ALL. PMID:27899526

Effects of Hematopoietic Lineage and Precursor Age on CML Disease Progression

DTIC Science & Technology

2007-03-01

ABL gene was inserted is bi-cistronic and contains the gene encoding green fluorescence protein (GFP) in addition to BCR-ABL, we were able to assess...ribosome entry site (IRES) enhanced green fluorescent protein (EGFP) or 5’ LTR-driven IRES EGFP for 24-36 hours; We received the BCR-ABL construct...from our collaborator, Dr. Owen Witte. This gene was then inserted into a murine retrovirus. We then prepared stocks of retrovirus to be used for

A longitudinal evaluation of performance of automated BCR-ABL1 quantitation using cartridge-based detection system.

PubMed

Enjeti, Anoop; Granter, Neil; Ashraf, Asma; Fletcher, Linda; Branford, Susan; Rowlings, Philip; Dooley, Susan

2015-10-01

An automated cartridge-based detection system (GeneXpert; Cepheid) is being widely adopted in low throughput laboratories for monitoring BCR-ABL1 transcript in chronic myelogenous leukaemia. This Australian study evaluated the longitudinal performance specific characteristics of the automated system.The automated cartridge-based system was compared prospectively with the manual qRT-PCR-based reference method at SA Pathology, Adelaide, over a period of 2.5 years. A conversion factor determination was followed by four re-validations. Peripheral blood samples (n = 129) with international scale (IS) values within detectable range were selected for assessment. The mean bias, proportion of results within specified fold difference (2-, 3- and 5-fold), the concordance rate of major molecular remission (MMR) and concordance across a range of IS values on paired samples were evaluated.The initial conversion factor for the automated system was determined as 0.43. Except for the second re-validation, where a negative bias of 1.9-fold was detected, all other biases fell within desirable limits. A cartridge-specific conversion factor and efficiency value was introduced and the conversion factor was confirmed to be stable in subsequent re-validation cycles. Concordance with the reference method/laboratory at >0.1-≤10 IS was 78.2% and at ≤0.001 was 80%, compared to 86.8% in the >0.01-≤0.1 IS range. The overall and MMR concordance were 85.7% and 94% respectively, for samples that fell within ± 5-fold of the reference laboratory value over the entire period of study.Conversion factor and performance specific characteristics for the automated system were longitudinally stable in the clinically relevant range, following introduction by the manufacturer of lot specific efficiency values.

Effective targeting of STAT5-mediated survival in myeloproliferative neoplasms using ABT-737 combined with rapamycin

PubMed Central

Li, Geqiang; Miskimen, Kristy L.; Wang, Zhengqi; Xie, Xiu Yan; Tse, William; Gouilleux, Fabrice; Moriggl, Richard; Bunting, Kevin D.

2010-01-01

Signal transducer and activator of transcription-5 (STAT5) is a critical transcription factor for normal hematopoiesis and its sustained activation is associated with hematologic malignancy. A persistently active mutant of STAT5 (STAT5aS711F) associates with Grb2 associated binding protein 2 (Gab2) in myeloid leukemias and promotes growth in vitro through AKT activation. Here we have retrovirally transduced wild-type or Gab2−/− mouse bone marrow cells expressing STAT5aS711F and transplanted into irradiated recipient mice to test an in vivo myeloproliferative disease (MPD) model. To target Gab2-independent AKT/mTOR activation, wild-type mice were treated separately with rapamycin. In either case, mice lacking Gab2 or treated with rapamycin displayed attenuated myeloid hyperplasia and modestly improved survival, but the effects were not cytotoxic and were reversible. To improve upon this approach, in vitro targeting of STAT5-mediated AKT/mTOR using rapamycin was combined with inhibition of the STAT5 direct target genes bcl-2 and bcl-XL using ABT-737. Striking synergy with both drugs was observed in mouse BaF3 cells expressing STAT5aS711F, TEL-JAK2, or BCR-ABL and in the relatively single agent-resistant human BCR-ABL positive K562 cell line. Therefore, targeting distinct STAT5 mediated survival signals, e.g. bcl-2/bcl-XL and AKT/mTOR may be an effective therapeutic approach for human myeloproliferative neoplasms. PMID:20535152

Rac-mediated Stimulation of Phospholipase Cγ2 Amplifies B Cell Receptor-induced Calcium Signaling*♦

PubMed Central

Walliser, Claudia; Tron, Kyrylo; Clauss, Karen; Gutman, Orit; Kobitski, Andrei Yu.; Retlich, Michael; Schade, Anja; Röcker, Carlheinz; Henis, Yoav I.; Nienhaus, G. Ulrich; Gierschik, Peter

2015-01-01

The Rho GTPase Rac is crucially involved in controlling multiple B cell functions, including those regulated by the B cell receptor (BCR) through increased cytosolic Ca2+. The underlying molecular mechanisms and their relevance to the functions of intact B cells have thus far remained unknown. We have previously shown that the activity of phospholipase Cγ2 (PLCγ2), a key constituent of the BCR signalosome, is stimulated by activated Rac through direct protein-protein interaction. Here, we use a Rac-resistant mutant of PLCγ2 to functionally reconstitute cultured PLCγ2-deficient DT40 B cells and to examine the effects of the Rac-PLCγ2 interaction on BCR-mediated changes of intracellular Ca2+ and regulation of Ca2+-regulated and nuclear-factor-of-activated-T-cell-regulated gene transcription at the level of single, intact B cells. The results show that the functional Rac-PLCγ2 interaction causes marked increases in the following: (i) sensitivity of B cells to BCR ligation; (ii) BCR-mediated Ca2+ release from intracellular stores; (iii) Ca2+ entry from the extracellular compartment; and (iv) nuclear translocation of the Ca2+-regulated nuclear factor of activated T cells. Hence, Rac-mediated stimulation of PLCγ2 activity serves to amplify B cell receptor-induced Ca2+ signaling. PMID:25903139

Interaction of the B cell-specific transcriptional coactivator OCA-B and galectin-1 and a possible role in regulating BCR-mediated B cell proliferation.

PubMed

Yu, Xin; Siegel, Rachael; Roeder, Robert G

2006-06-02

OCA-B is a B cell-specific transcriptional coactivator for OCT factors during the activation of immunoglobulin genes. In addition, OCA-B is crucial for B cell activation and germinal center formation. However, the molecular mechanisms for OCA-B function in these processes are not clear. Our previous studies documented two OCA-B isoforms and suggested a novel mechanism for the function of the myristoylated, membrane-bound form of OCA-B/p35 as a signaling molecule. Here, we report the identification of galectin-1, and related galectins, as a novel OCA-B-interacting protein. The interaction of OCA-B and galectin-1 can be detected both in vivo and in vitro. The galectin-1 binding domain in OCA-B has been localized to the N terminus of OCA-B. In B cells lacking OCA-B expression, increased galectin-1 expression, secretion, and cell surface association are observed. Consistent with these observations, and a reported inhibitory interaction of galectin-1 with CD45, the phosphatase activity of CD45 is reduced modestly, but significantly, in OCA-B-deficient B cells. Finally, galectin-1 is shown to negatively regulate B cell proliferation and tyrosine phosphorylation upon BCR stimulation. Together, these results raise the possibility that OCA-B may regulate BCR signaling through an association with galectin-1.

Use of deferasirox, an iron chelator, to overcome imatinib resistance of chronic myeloid leukemia cells

PubMed Central

Kim, Dae Sik; Na, Yoo Jin; Kang, Myoung Hee; Yoon, Soo-Young; Choi, Chul Won

2016-01-01

Background/Aims: The treatment of chronic myeloid leukemia (CML) has achieved impressive success since the development of the Bcr-Abl tyrosine kinase inhibitor, imatinib mesylate. Nevertheless, resistance to imatinib has been observed, and a substantial number of patients need alternative treatment strategies. Methods: We have evaluated the effects of deferasirox, an orally active iron chelator, and imatinib on K562 and KU812 human CML cell lines. Imatinib-resistant CML cell lines were created by exposing cells to gradually increasing concentrations of imatinib. Results: Co-treatment of cells with deferasirox and imatinib induced a synergistic dose-dependent inhibition of proliferation of both CML cell lines. Cell cycle analysis showed an accumulation of cells in the subG1 phase. Western blot analysis of apoptotic proteins showed that co-treatment with deferasirox and imatinib induced an increased expression of apoptotic proteins. These tendencies were clearly identified in imatinib-resistant CML cell lines. The results also showed that co-treatment with deferasirox and imatinib reduced the expression of BcrAbl, phosphorylated Bcr-Abl, nuclear factor-κB (NF-κB) and β-catenin. Conclusions: We observed synergistic effects of deferasirox and imatinib on both imatinib-resistant and imatinib-sensitive cell lines. These effects were due to induction of apoptosis and cell cycle arrest by down-regulated expression of NF-κB and β-catenin levels. Based on these results, we suggest that a combination treatment of deferasirox and imatinib could be considered as an alternative treatment option for imatinib-resistant CML. PMID:26874514

JAK2 aberrations in childhood B-cell precursor acute lymphoblastic leukemia

PubMed Central

de Goffau-Nobel, Willemieke; Hoogkamer, Alex Q.; Boer, Judith M.; Boeree, Aurélie; van de Ven, Cesca; Koudijs, Marco J.; Besselink, Nicolle J.M.; de Groot-Kruseman, Hester A.; Zwaan, Christian Michel; Horstmann, Martin A.; Pieters, Rob; den Boer, Monique L.

2017-01-01

JAK2 abnormalities may serve as target for precision medicines in pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL). In the current study we performed a screening for JAK2 mutations and translocations, analyzed the clinical outcome and studied the efficacy of two JAK inhibitors in primary BCP-ALL cells. Importantly, we identify a number of limitations of JAK inhibitor therapy. JAK2 mutations mainly occurred in the poor prognostic subtypes BCR-ABL1-like and non- BCR-ABL1-like B-other (negative for sentinel cytogenetic lesions). JAK2 translocations were restricted to BCR-ABL1-like cases. Momelotinib and ruxolitinib were cytotoxic in both JAK2 translocated and JAK2 mutated cells, although efficacy in JAK2 mutated cells highly depended on cytokine receptor activation by TSLP. However, our data also suggest that the effect of JAK inhibition may be compromised by mutations in alternative survival pathways and microenvironment-induced resistance. Furthermore, inhibitors induced accumulation of phosphorylated JAK2Y1007, which resulted in a profound re-activation of JAK2 signaling upon release of the inhibitors. This preclinical evidence implies that further optimization and evaluation of JAK inhibitor treatment is necessary prior to its clinical integration in pediatric BCP-ALL. PMID:29163799

Mechanisms of genesis of variant translocation in chronic myeloid leukemia are not correlated with ABL1 or BCR deletion status or response to imatinib therapy.

PubMed

Richebourg, Steven; Eclache, Virginie; Perot, Christine; Portnoi, Marie-France; Van den Akker, Jacqueline; Terré, Christine; Maareck, Odile; Soenen, Valérie; Viguié, Franck; Laï, Jean-Luc; Andrieux, Joris; Corm, Sélim; Roche-Lestienne, Catherine

2008-04-15

Many published studies have indicated that various mechanisms could be involved in the genesis of variant chronic myelogeneous leukemia (CML) translocations. These are mainly one-step or two-step mechanisms, associated or not with deletions adjacent to the translocation junction on der(9) or der(22) chromosomes (or both). Based on the mechanism of genesis, it has been suggested that the complexity may affect the occurrence of ABL1 and BCR deletions (either or both), or may be associated with the CML disease course, and thus could determine the response to imatinib therapy. Through a retrospective molecular cytogenetic study of 41 CML patients with variant Philadelphia chromosome (Ph), we explored the genesis of these variant rearrangements and analyzed the correlation with deletion status and imatinib efficiency. Our results confirmed that the one-step mechanism is the most frequent, evidenced in 30 of 41 patients (73%); 3 patients demonstrated other more complex multistep events and 8 patients (19.5%) harbored ABL1 or BCR deletions that are not significantly associated with the complexity of translocation genesis. We also found no association between one-step, two-step, or multistep mechanisms and the response to imatinib therapy.

Treatment-free remission following frontline nilotinib in patients with chronic myeloid leukemia in chronic phase: results from the ENESTfreedom study.

PubMed

Hochhaus, A; Masszi, T; Giles, F J; Radich, J P; Ross, D M; Gómez Casares, M T; Hellmann, A; Stentoft, J; Conneally, E; García-Gutiérrez, V; Gattermann, N; Wiktor-Jedrzejczak, W; le Coutre, P D; Martino, B; Saussele, S; Menssen, H D; Deng, W; Krunic, N; Bedoucha, V; Saglio, G

2017-07-01

The single-arm, phase 2 ENESTfreedom trial assessed the potential for treatment-free remission (TFR; i.e., the ability to maintain a molecular response after stopping therapy) following frontline nilotinib treatment. Patients with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase with MR 4.5 (BCR-ABL1⩽0.0032% on the International Scale (BCR-ABL1 IS )) and ⩾2 years of frontline nilotinib therapy were enrolled. Patients with sustained deep molecular response during the 1-year nilotinib consolidation phase were eligible to stop treatment and enter the TFR phase. Patients with loss of major molecular response (MMR; BCR-ABL1 IS ⩽0.1%) during the TFR phase reinitiated nilotinib. In total, 215 patients entered the consolidation phase, of whom 190 entered the TFR phase. The median duration of nilotinib before stopping treatment was 43.5 months. At 48 weeks after stopping nilotinib, 98 patients (51.6%; 95% confidence interval, 44.2-58.9%) remained in MMR or better (primary end point). Of the 86 patients who restarted nilotinib in the treatment reinitiation phase after loss of MMR, 98.8% and 88.4%, respectively, regained MMR and MR 4.5 by the data cutoff date. Consistent with prior reports of imatinib-treated patients, musculoskeletal pain-related events were reported in 24.7% of patients in the TFR phase (consolidation phase, 16.3%).

Evaluation of the association between the JAK2 46/1 haplotype and chronic myeloproliferative neoplasms in a Brazilian population

PubMed Central

Silva, Sarah Pagliarini- e-; Santos, Bruna Cunha; de Figueiredo Pereira, Elizangela Mendes; Ferreira, Mari Ellen; Baraldi, Elaine Cristina; Sell, Ana Maria; Visentainer, Jeane Eliete Laguila

2013-01-01

OBJECTIVE: The JAK2 46/1 haplotype has recently been described as a major contributing factor to the development of myeloproliferative neoplasm, whether positive or negative for the JAK2 V617F mutation. The G allele, identified by a single-nucleotide polymorphism known as JAK2 rs10974944, is part of the JAK2 46/1 haplotype. The aim of this study was to verify the association between the presence of the G allele and the development of BCR-ABL-negative chronic myeloproliferative neoplasms in our population. METHODS: Blood and oral mucosa swab samples were obtained from 56 patients of two local Brazilian hospitals who had previously been diagnosed with BCR-ABL-negative chronic myeloproliferative neoplasms. Blood samples from 90 local blood donors were used as controls. The presence of the G allele was assessed using a PCR-RFLP assay after extracting DNA from the samples. RESULTS: The presence of the G allele was strongly associated with the presence of BCR-ABL-negative chronic myeloproliferative neoplasms (p = 0.0001; OR = 2.674; 95% CI = 1.630−4.385) in the studied population. CONCLUSION: In agreement with previous reports, the JAK2 46/1 haplotype, represented in this study by the presence of the G allele, is an important predisposing factor in the oncogenetic development of these neoplasms in our population. PMID:23420150

Heat shock protein-70 neutralizes apoptosis inducing factor in Bcr/Abl expressing cells.

PubMed

Wang, Fang; Dai, An-Ya; Tao, Kun; Xiao, Qing; Huang, Zheng-Lan; Gao, Miao; Li, Hui; Wang, Xin; Cao, Wei-Xi; Feng, Wen-Li

2015-10-01

Bcr/Abl fusion protein is a hallmark of human chronic myeloid leukemia (CML). The protein can activate various signaling pathways to make normal cells transform malignantly and thus to facilitate tumorigenesis. It has been reported that heat shock protein-70 (HSP-70) can be served as an anti-apoptotic protein that suppresses Bax and Apo-2L/TRAIL. But it is unclear whether HSP-70 affects AIF-initiated apoptosis in Bcr/Abl expressing cells considering that HSP-70 is coincidentally over-regulated in these cells. Our findings supported that abundant HSP-70 in Bcr/Abl cells neutralizes AIF by segregating it from nucleus via direct interaction, leading to the failure of AIF initiating cell death and the silence of caspase-independent apoptotic pathway upon apoptotic induction. Moderate inhibition of HSP-70 expression by siRNA leads to Vp-16 triggered re-distribution of AIF in nucleus. In addition, AIF bears a HSP-70 binding domain allowing association with HSP-70. Therefore, disruption of the association using an AIF mutant lacking this domain can restore the potential of AIF importing into nucleus, and finally triggers cell death in a time dependent manner. Copyright © 2015 Elsevier Inc. All rights reserved.

Structure and Dynamic Regulation of Abl Kinases*

PubMed Central

Panjarian, Shoghag; Iacob, Roxana E.; Chen, Shugui; Engen, John R.; Smithgall, Thomas E.

2013-01-01

The c-abl proto-oncogene encodes a unique protein-tyrosine kinase (Abl) distinct from c-Src, c-Fes, and other cytoplasmic tyrosine kinases. In normal cells, Abl plays prominent roles in cellular responses to genotoxic stress as well as in the regulation of the actin cytoskeleton. Abl is also well known in the context of Bcr-Abl, the oncogenic fusion protein characteristic of chronic myelogenous leukemia. Selective inhibitors of Bcr-Abl, of which imatinib is the prototype, have had a tremendous impact on clinical outcomes in chronic myelogenous leukemia and revolutionized the field of targeted cancer therapy. In this minireview, we focus on the structural organization and dynamics of Abl kinases and how these features influence inhibitor sensitivity. PMID:23316053

FcgammaRIIB signals inhibit BLyS signaling and BCR-mediated BLyS receptor up-regulation.

PubMed

Crowley, Jenni E; Stadanlick, Jason E; Cambier, John C; Cancro, Michael P

2009-02-12

These studies investigate how interactions between the BCR and FcgammaRIIB affect B lymphocyte stimulator (BLyS) recep-tor expression and signaling. Previous studies showed that BCR ligation up-regulates BLyS binding capacity in mature B cells, reflecting increased BLyS receptor levels. Here we show that FcgammaRIIB coaggregation dampens BCR-induced BLyS receptor up-regulation. This cross-regulation requires BCR and FcgammaRIIB coligation, and optimal action relies on the Src-homology-2 (SH2)-containing inositol 5 phosphase-1 (SHIP1). Subsequent to FcgammaRIIB/BCR coaggregation, the survival promoting actions of BLyS are attenuated, reflecting reduced BLyS receptor signaling capacity in terms of Pim 2 maintenance, noncanonical NF-kappaB activation, and Bcl-xL levels. These findings link the negative regulatory functions of FcgammaRIIB with BLyS-mediated B-cell survival.

Activity of dual SRC-ABL inhibitors highlights the role of BCR/ABL kinase dynamics in drug resistance

PubMed Central

Azam, Mohammad; Nardi, Valentina; Shakespeare, William C.; Metcalf, Chester A.; Bohacek, Regine S.; Wang, Yihan; Sundaramoorthi, Raji; Sliz, Piotr; Veach, Darren R.; Bornmann, William G.; Clarkson, Bayard; Dalgarno, David C.; Sawyer, Tomi K.; Daley, George Q.

2006-01-01

Mutation in the ABL kinase domain is the principal mechanism of imatinib resistance in patients with chronic myelogenous leukemia. Many mutations favor active kinase conformations that preclude imatinib binding. Because the active forms of ABL and SRC resemble one another, we tested two dual SRC-ABL kinase inhibitors, AP23464 and PD166326, against 58 imatinib-resistant (IMR) BCR/ABL kinase variants. Both compounds potently inhibit most IMR variants, and in vitro drug selection demonstrates that active (AP23464) and open (PD166326) conformation-specific compounds are less susceptible to resistance than imatinib. Combinations of inhibitors suppressed essentially all resistance mutations, with the notable exception of T315I. Guided by mutagenesis studies and molecular modeling, we designed a series of AP23464 analogues to target T315I. The analogue AP23846 inhibited both native and T315I variants of BCR/ABL with submicromolar potency but showed nonspecific cellular toxicity. Our data illustrate how conformational dynamics of the ABL kinase accounts for the activity of dual SRC-ABL inhibitors against IMR-mutants and provides a rationale for combining conformation specific inhibitors to suppress resistance. PMID:16754879

Discovery of 4-Methyl-N-(4-((4-methylpiperazin-1-yl)methyl)-3-(trifluoromethyl)phenyl)-3-((1-nicotinoylpiperidin-4-yl)oxy)benzamide (CHMFL-ABL/KIT-155) as a Novel Highly Potent Type II ABL/KIT Dual Kinase Inhibitor with a Distinct Hinge Binding.

PubMed

Wang, Qiang; Liu, Feiyang; Wang, Beilei; Zou, Fengming; Qi, Ziping; Chen, Cheng; Yu, Kailin; Hu, Chen; Qi, Shuang; Wang, Wenchao; Hu, Zhenquan; Liu, Juan; Wang, Wei; Wang, Li; Liang, Qianmao; Zhang, Shanchun; Ren, Tao; Liu, Qingsong; Liu, Jing

2017-01-12

The discovery of a novel potent type II ABL/c-KIT dual kinase inhibitor compound 34 (CHMFL-ABL/KIT-155), which utilized a hydrogen bond formed by NH on the kinase backbone and carbonyl oxygen of 34 as a unique hinge binding, is described. 34 potently inhibited purified ABL (IC 50 : 46 nM) and c-KIT kinase (IC 50 : 75 nM) in the biochemical assays and displayed high selectivity (S Score (1) = 0.03) at the concentration of 1 μM among 468 kinases/mutants in KINOMEscan assay. It exhibited strong antiproliferative activities against BCR-ABL/c-KIT driven CML/GISTs cancer cell lines through blockage of the BCR-ABL/c-KIT mediated signaling pathways, arresting cell cycle progression and induction of apoptosis. 34 possessed a good oral PK property and effectively suppressed the tumor progression in the K562 (CML) and GIST-T1 (GISTs) cells mediated xenograft mouse model. The distinct hinge-binding mode of 34 provided a novel pharmacophore for expanding the chemical structure diversity for the type II kinase inhibitors discovery.

Umbilical Cord Blood Transplant, Cyclophosphamide, Fludarabine Phosphate, and Total-Body Irradiation in Treating Patients With Hematologic Disease

ClinicalTrials.gov

2018-03-23

Acute Biphenotypic Leukemia; Acute Myeloid Leukemia Arising From Previous Myelodysplastic Syndrome; Acute Myeloid Leukemia in Remission; Adult Acute Lymphoblastic Leukemia in Complete Remission; Aggressive Non-Hodgkin Lymphoma; Beta-2-Microglobulin Greater Than 3 g/mL; Blasts Under 5 Percent of Bone Marrow Nucleated Cells; Burkitt Lymphoma; Childhood Acute Lymphoblastic Leukemia in Complete Remission; Chromosome 13 Abnormality; Chronic Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Lymphoblastic Lymphoma; Mantle Cell Lymphoma; Myelodysplastic Syndrome With Excess Blasts; Myelofibrosis; Pancytopenia; Plasma Cell Myeloma; Prolymphocytic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Recurrent Chronic Lymphocytic Leukemia; Recurrent Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Recurrent Follicular Lymphoma; Recurrent Lymphoplasmacytic Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma

Chronic myeloid leukaemia with extreme thrombocytosis.

PubMed

Verma, Shailendra Prasad; Subbiah, Arunkumar; Jacob, Sajini Elizabeth; Basu, Debdatta

2015-08-19

We report two cases of chronic myeloid leukaemia (CML) with extreme thrombocytosis. The first patient was a 65-year-old man who presented with prolonged history of upper abdominal discomfort, anorexia and two episodes of recent gum bleeds without fever or other bleeding manifestations. He was a chronic smoker with no other comorbidities. Examination revealed moderate hepatosplenomegaly. On investigation, he was found to have extreme thrombocytosis (3,500,000/mm(3)) and leucocytosis with moderate anaemia. In view of the leucocytosis, he was investigated for CML and found to be positive for BCR-ABL by reverse transcription PCR (RT-PCR). He received imatinib 400 mg/day and achieved complete haematological response at the end of 3 months. The second patient was a 7-year-old boy who presented with fever, cough and cold of 2-week duration. Examination revealed mild hepatomegaly with palpable spleen tip. Haemogram and peripheral smear revealed moderate leucocytosis with extreme thrombocytosis (2,800,000/mm(3)). On evaluation, he was found to be BCR-ABL positive and responded well to imatinib treatment. In both these cases, massive thrombocytosis was an unusual presentation of a well-known entity, namely, CML. This degree of thrombocytosis is usually seen only in essential thrombocytosis. 2015 BMJ Publishing Group Ltd.

Effects of antioxidants on apoptosis induced by dasatinib and nilotinib in K562 cells.

PubMed

Damiano, Sara; Montagnaro, Serena; Puzio, Maria V; Severino, Lorella; Pagnini, Ugo; Barbarino, Marcella; Cesari, Daniele; Giordano, Antonio; Florio, Salvatore; Ciarcia, Roberto

2018-06-01

In clinical practice for the treatment of chronic myeloid leukemia, second generation of tyrosine kinase inhibitors such as Nilotinib (NIL) specific and potent inhibitor of the BCR/ABL kinase and Dasatinib (DAS) a inhibitor of BCR/ABL and Src family kinase were developed to clinically overcome imatinib resistance. In this study, we wanted to test the ability of some antioxidants such Resveratrol (RES) or a new recombinant mitochondrial manganese containing superoxide dismutase (rMnSOD) or δ-tocotrienol (δ-TOCO) to interact with DAS and NIL on viability, reactive oxygen species (ROS) production, lipid peroxidation, and apoptosis. To test the possible mechanisms of action of such antioxidants, we utilized N-acetyl-L-cysteine (NAC) a specific inhibitor ROS production or PP1 a specific Src tyrosine kinase inhibitor or BAPTA a specific chelator of intracellular calcium. Our data demonstrated: 1) RES, rMnSOD, δ-TOCO, and NAC, at dose used, significantly reduced the intracellular levels of MDA induced by DAS or NIL; 2) RES, rMnSOD, and δ-TOCO increased the intracellular ROS levels; 3) The increase ROS levels is related to higher levels of oligonucleosomesi induced by DAS and NIL and that NAC significantly reduced this activity. Interestingly, our data showed that apoptotic activity of DAS and NIL have significantly increased the production of oligonucleosomes by triggering excessive ROS generation as well as functionality of SERCA receptors. © 2018 Wiley Periodicals, Inc.

The predictive value of early molecular response in chronic myeloid leukaemia patients treated with imatinib in a single real-world medical centre in a developing country.

PubMed

Bee, Ping Chong; Sekaran, Veera; Ng, Richard Rui Jie; Kweh, Ting Yi; Gan, Gin Gin

2017-03-01

The prognosis of patients with chronic myeloid leukaemia (CML) has improved since the introduction of imatinib. However, patients who do not achieve complete cytogenetic response (CCyR) and major molecular response (MMR) have poorer prognosis. Recent clinical trials have demonstrated that early and deeper cytogenetic and molecular responses predict a better long-term outcome. This study aimed to analyse the relationship between early molecular response and clinical outcome in a real-life setting. This retrospective study included all patients with CML, in chronic or accelerated phase, who were treated with imatinib at University of Malaya Medical Centre, Malaysia. A total of 70 patients were analysed. The median follow-up duration was 74 months, and the cumulative percentages of patients with CCyR and MMR were 80.0% and 65.7%, respectively. Overall survival (OS) and event-free survival (EFS) at ten years were 94.3% and 92.9%, respectively. Patients who achieved CCyR and MMR had significantly better OS and EFS than those who did not. At six months, patients who had a BCR-ABL level ≤ 10% had significantly better OS and EFS than those who had a BCR-ABL level > 10%. The target milestone of CCyR at 12 months and MMR at 18 months showed no survival advantage in our patients. Our data showed that imatinib is still useful as first-line therapy. However, vigilant monitoring of patients who have a BCR-ABL level > 10% at six months of treatment should be implemented so that prompt action can be taken to provide the best outcome for these patients. Copyright: © Singapore Medical Association

A Non-ATP Competitive Inhibitor of BCR-ABL for the Therapy of Imatinib-Resistant Cmls

DTIC Science & Technology

2008-05-01

HSP90 members (e.g. HSP70 and HSP27 ) help maintain the macromolecular complex that assembled the Bcr-Abl/Jak2 signaling Network. Our published papers 4...kinase, Akt and GSK3 beta. Our recent findings suggest that the HSP90/HSP70/ HSP27 chaperone proteins are also part of this Network, and may play a

Acquisition of genomic events leading to lymphoblastic transformation in a rare case of myeloproliferative neoplasm with BCR-JAK2 fusion transcript.

PubMed

Duployez, Nicolas; Nibourel, Olivier; Ducourneau, Benoît; Grardel, Nathalie; Boyer, Thomas; Bories, Claire; Darre, Stéphane; Coiteux, Valérie; Berthon, Céline; Preudhomme, Claude; Roche-Lestienne, Catherine

2016-10-01

We report a case of myeloproliferative neoplasm (MPN) with an atypical t(9;22;15)(p24;q11;q21) translocation, leading to a BCR-JAK2 fusion, associated with a trisomy of chromosome 8 in clonal evolution at karyotype. Patient's evolution was marked by an aggressive clinical course with rapid progression to blast phase within the first year after diagnosis. Examination of matched chronic phase and blast crisis samples by SNP-array karyotyping identified secondary acquired cryptic genetic events at the time of lymphoblastic transformation, including biallelic IKZF1 alteration and EBF1 and CDKN2A/B codeletions. This case is the first report describing acquisition of secondary genetic events leading to acute lymphoblastic progression in a rare MPN with BCR-JAK2 fusion. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Computational study of molecular electrostatic potential, docking and dynamics simulations of gallic acid derivatives as ABL inhibitors.

PubMed

Raghi, K R; Sherin, D R; Saumya, M J; Arun, P S; Sobha, V N; Manojkumar, T K

2018-04-05

Chronic myeloid leukemia (CML), a hematological malignancy arises due to the spontaneous fusion of the BCR and ABL gene, resulting in a constitutively active tyrosine kinase (BCR-ABL). Pharmacological activity of Gallic acid and 1,3,4-Oxadiazole as potential inhibitors of ABL kinase has already been reported. Objective of this study is to evaluate the ABL kinase inhibitory activity of derivatives of Gallic acid fused with 1,3,4-Oxadiazole moieties. Attempts have been made to identify the key structural features responsible for drug likeness of the Gallic acid and the 1,3,4-Oxadiazole ring using molecular electrostatic potential maps (MESP). To investigate the inhibitory activity of Gallic acid derivatives towards the ABL receptor, we have applied molecular docking and molecular dynamics (MD) simulation approaches. A comparative study was performed using Bosutinib as the standard which is an approved CML drug acting on the same receptor. Furthermore, the novel compounds designed and reported here in were evaluated for ADME properties and the results indicate that they show acceptable pharmacokinetic properties. Accordingly these compounds are predicted to be drug like with low toxicity potential. Copyright © 2018 Elsevier Ltd. All rights reserved.

[History of chronic myeloid leukemia: a paradigm in the treatment of cancer].

PubMed

Gonon-Demoulian, R; Goldman, J M; Nicolini, F E

2014-01-01

During two centuries, advances in medicine and medical research have helped to understand the pathophysiology of chronic myelogenous leukemia (CML). This hematologic malignancy is a unique model of oncogenesis where a single molecular hit, causing cell proliferation and survival, was identified. The chromosomal abnormality first highlighted by P. Nowell and D. Hungerford in 1960, and characterized as the reciprocal translocation t(9;22)(q34;q11), the Philadelphia chromosome, discovered in leukemic cells, by J. Rowley in 1973. At the end of the 20th century, the contribution of molecular biology techniques was crucial by the discovery of the BCR-ABL1 hybrid oncogene derived from the t(9;22), responsible for the translation of an aberrant protein tyrosine kinase. This BCR-ABL1 kinase deregulates signaling pathways that control normal cell cycle and survival in primitive hematopoietic cells and is thus responsible for malignant cell accumulation observed in CML. It was then only necessary to develop a targeted treatment adapted to this molecular hit. Recently, tyrosine kinase inhibitors, by their specific inhibitory activity of BCR-ABL, have revolutionized the treatment of CML, allowing rates of haematological, cytogenetic and molecular responses never seen to date, and has significantly improved the overall survival and the quality of life of patients.

Identification of Genes Upregulated by the Transcription Factor Bcr1 That Are Involved in Impermeability, Impenetrability, and Drug Resistance of Candida albicans a/α Biofilms

PubMed Central

Srikantha, Thyagarajan; Daniels, Karla J.; Pujol, Claude; Kim, Elena

2013-01-01

Candida albicans forms two types of biofilm, depending upon the configuration of the mating type locus. Although architecturally similar, a/α biofilms are impermeable, impenetrable, and drug resistant, whereas a/a and α/α biofilms lack these traits. The difference appears to be the result of an alternative matrix. Overexpression in a/a cells of BCR1, a master regulator of the a/α matrix, conferred impermeability, impenetrability, and drug resistance to a/a biofilms. Deletion of BCR1 in a/α cells resulted in the loss of these a/α-specific biofilm traits. Using BCR1 overexpression in a/a cells, we screened 107 genes of interest and identified 8 that were upregulated by Bcr1. When each was overexpressed in a/a biofilms, the three a/α traits were partially conferred, and when each was deleted in a/α cells, the traits were partially lost. Five of the eight genes have been implicated in iron homeostasis, and six encode proteins that are either in the wall or plasma membrane or secreted. All six possess sites for O-linked and N-linked glycosylation that, like glycosylphosphatidylinositol (GPI) anchors, can cross-link to the wall and matrix, suggesting that they may exert a structural role in conferring impermeability, impenetrability, and drug resistance, in addition to their physiological functions. The fact that in a screen of 107 genes, all 8 of the Bcr1-upregulated genes identified play a role in impermeability, impenetrability, and drug resistance suggests that the formation of the a/α matrix is highly complex and involves a larger number of genes than the initial ones identified here. PMID:23563485

B cell TLR1/2, TLR4, TLR7 and TLR9 interact in induction of class switch DNA recombination: modulation by BCR and CD40, and relevance to T-independent antibody responses.

PubMed

Pone, Egest J; Lou, Zheng; Lam, Tonika; Greenberg, Milton L; Wang, Rui; Xu, Zhenming; Casali, Paolo

2015-02-01

Ig class switch DNA recombination (CSR) in B cells is crucial to the maturation of antibody responses. It requires IgH germline IH-CH transcription and expression of AID, both of which are induced by engagement of CD40 or dual engagement of a Toll-like receptor (TLR) and B cell receptor (BCR). Here, we have addressed cross-regulation between two different TLRs or between a TLR and CD40 in CSR induction by using a B cell stimulation system involving lipopolysaccharides (LPS). LPS-mediated long-term primary class-switched antibody responses and memory-like antibody responses in vivo and induced generation of class-switched B cells and plasma cells in vitro. Consistent with the requirement for dual TLR and BCR engagement in CSR induction, LPS, which engages TLR4 through its lipid A moiety, triggered cytosolic Ca2+ flux in B cells through its BCR-engaging polysaccharidic moiety. In the presence of BCR crosslinking, LPS synergized with a TLR1/2 ligand (Pam3CSK4) in CSR induction, but much less efficiently with a TLR7 (R-848) or TLR9 (CpG) ligand. In the absence of BCR crosslinking, R-848 and CpG, which per se induced marginal CSR, virtually abrogated CSR to IgG1, IgG2a, IgG2b, IgG3 and/or IgA, as induced by LPS or CD154 (CD40 ligand) plus IL-4, IFN-γ or TGF-β, and reduced secretion of class-switched Igs, without affecting B cell proliferation or IgM expression. The CSR inhibition by TLR9 was associated with the reduction in AID expression and/or IgH germline IH-S-CH transcription, and required co-stimulation of B cells by CpG with LPS or CD154. Unexpectedly, B cells also failed to undergo CSR or plasma cell differentiation when co-stimulated by LPS and CD154. Overall, by addressing the interaction of TLR1/2, TLR4, TLR7 and TLR9 in the induction of CSR and modulation of TLR-dependent CSR by BCR and CD40, our study suggests the complexity of how different stimuli cross-regulate an important B cell differentiation process and an important role of TLRs in inducing effective T-independent antibody responses to microbial pathogens, allergens and vaccines.

B cell TLR1/2, TLR4, TLR7 and TLR9 interact in induction of class switch DNA recombination: modulation by BCR and CD40, and relevance to T-independent antibody responses

PubMed Central

Pone, Egest J.; Lou, Zheng; Lam, Tonika; Greenberg, Milton L.; Wang, Rui; Xu, Zhenming; Casali, Paolo

2015-01-01

Ig class switch DNA recombination (CSR) in B cells is crucial to the maturation of antibody responses. It requires IgH germline IH-CH transcription and expression of AID, both of which are induced by engagement of CD40 or dual engagement of a Toll-like receptor (TLR) and B cell receptor (BCR). Here, we have addressed cross-regulation between two different TLRs or between a TLR and CD40 in CSR induction by using a B cell stimulation system involving lipopolysaccharides (LPS). LPS mediated long-term primary class-switched antibody responses and memory-like antibody responses in vivo and induced generation of class-switched B cells and plasma cells in vitro. Consistent with the requirement for dual TLR and BCR engagement in CSR induction, LPS, which engages TLR4 through its lipid A moiety, triggered cytosolic Ca2+ flux in B cells through its BCR-engaging polysaccharidic moiety. In the presence of BCR crosslinking, LPS synergized with a TLR1/2 ligand (Pam3CSK4) in CSR induction, but much less efficiently with a TLR7 (R-848) or TLR9 (CpG) ligand. In the absence of BCR crosslinking, R-848 and CpG, which per se induced marginal CSR, virtually abrogated CSR to IgG1, IgG2a, IgG2b, IgG3 and/or IgA, as induced by LPS or CD154 (CD40 ligand) plus IL-4, IFN-γ or TGF-β, and reduced secretion of class-switched Igs, without affecting B cell proliferation or IgM expression. The CSR inhibition by TLR9 was associated with the reduction in AID expression and/or IgH germline IH-S-CH transcription, and required co-stimulation of B cells by CpG with LPS or CD154. Unexpectedly, B cells also failed to undergo CSR or plasma cell differentiation when co-stimulated by LPS and CD154. Overall, by addressing the interaction of TLR1/2, TLR4, TLR7 and TLR9 in the induction of CSR and modulation of TLR-dependent CSR by BCR and CD40, our study suggests the complexity of how different stimuli cross-regulate an important B cell differentiation process and an important role of TLRs in inducing effective T-independent antibody responses to microbial pathogens, allergens and vaccines. PMID:25536171

Ascorbate/menadione-induced oxidative stress kills cancer cells that express normal or mutated forms of the oncogenic protein Bcr-Abl. An in vitro and in vivo mechanistic study.

PubMed

Beck, Raphaël; Pedrosa, Rozangela Curi; Dejeans, Nicolas; Glorieux, Christophe; Levêque, Philippe; Gallez, Bernard; Taper, Henryk; Eeckhoudt, Stéphane; Knoops, Laurent; Calderon, Pedro Buc; Verrax, Julien

2011-10-01

Numerous studies suggest that generation of oxidative stress could be useful in cancer treatment. In this study, we evaluated, in vitro and in vivo, the antitumor potential of oxidative stress induced by ascorbate/menadione (asc/men). This combination of a reducing agent (ascorbate) and a redox active quinone (menadione) generates redox cycling leading to formation of reactive oxygen species (ROS). Asc/men was tested in several cell types including K562 cells (a stable human-derived leukemia cell line), freshly isolated leukocytes from patients with chronic myeloid leukemia, BaF3 cells (a murine pro-B cell line) transfected with Bcr-Abl and peripheral blood leukocytes derived from healthy donors. Although these latter cells were resistant to asc/men, survival of all the other cell lines was markedly reduced, including the BaF3 cells expressing either wild-type or mutated Bcr-Abl. In a standard in vivo model of subcutaneous tumor transplantation, asc/men provoked a significant delay in the proliferation of K562 and BaF3 cells expressing the T315I mutated form of Bcr-Abl. No effect of asc/men was observed when these latter cells were injected into blood of mice most probably because of the high antioxidant potential of red blood cells, as shown by in vitro experiments. We postulate that cancer cells are more sensitive to asc/men than healthy cells because of their lack of antioxidant enzymes, mainly catalase. The mechanism underlying this cytotoxicity involves the oxidative cleavage of Hsp90 with a subsequent loss of its chaperone function thus leading to degradation of wild-type and mutated Bcr-Abl protein.

Design, Synthesis and Biological Evaluation of Betulinic Acid Derivatives as New Antitumor Agents for Leukemia.

PubMed

Waechter, Fernanda; da Silva, Gloria N S; Willig, Julia B; de Oliveira, Cristiane B; Vieira, Bruna D; Trivella, Daniela B B; Zimmer, Aline R; Buffon, Andreia; Pilger, Diogo A; Gnoatto, Simone C B

2017-01-01

Chronic myeloid leukemia (CML) is currently treated with imatinib, a Bcr-Abl inhibitor. However, resistance to this drug usually develops over time. Triptolide, a diterpenoid triepoxide, has been shown active against CML cells resistant to imatinib, acting mainly on the level of Bcr-Abl transcription inhibition. Here, we used the triterpene betulinic acid, a known proteasome inhibitor with potential antileukemic activity, as a scaffold for the generation of analogues with predicted triptolide biological activity. Betulinic acid derivatives were designed based on the structure-activity relationship of triptolide and evaluated for their cytotoxic effects in CML cells, lymphocytes and human keratinocytes (HaCaT), as well as against the proteasome complex. The main modification performed on betulinic acid was fluorination at C-28 and epoxidation, both of which are responsible for enhancing activity of triptolide. A total of 10 compounds were obtained: 6 previously described and 4 novel compounds. The cytotoxic activity over a CML cell line (K562) was assessed using flow cytometry and compared to lymphocytes and HaCaT. The results show that betulinic acid was the most cytotoxic compound against CML cells, showing a good selectivity index for cancer over normal cells. The most important trend for the activity in betulinic acid derivatives is the presence of a free hydroxyl group at C-3 and a carboxyl group at C-28. Results also indicated that the epoxide is important for enhancing the activity, while modification at C-28 worsens the activity. Proteasome inhibition assays suggest that proteasome is the main target for betulinic acid and its derivatives. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Perturbation of B Cell Gene Expression Persists in HIV-Infected Children Despite Effective Antiretroviral Therapy and Predicts H1N1 Response.

PubMed

Cotugno, Nicola; De Armas, Lesley; Pallikkuth, Suresh; Rinaldi, Stefano; Issac, Biju; Cagigi, Alberto; Rossi, Paolo; Palma, Paolo; Pahwa, Savita

2017-01-01

Despite effective antiretroviral therapy (ART), HIV-infected individuals with apparently similar clinical and immunological characteristics can vary in responsiveness to vaccinations. However, molecular mechanisms responsible for such impairment, as well as biomarkers able to predict vaccine responsiveness in HIV-infected children, remain unknown. Following the hypothesis that a B cell qualitative impairment persists in HIV-infected children (HIV) despite effective ART and phenotypic B cell immune reconstitution, the aim of the current study was to investigate B cell gene expression of HIV compared to age-matched healthy controls (HCs) and to determine whether distinct gene expression patterns could predict the ability to respond to influenza vaccine. To do so, we analyzed prevaccination transcriptional levels of a 96-gene panel in equal numbers of sort-purified B cell subsets (SPBS) isolated from peripheral blood mononuclear cells using multiplexed RT-PCR. Immune responses to H1N1 antigen were determined by hemaglutination inhibition and memory B cell ELISpot assays following trivalent-inactivated influenza vaccination (TIV) for all study participants. Although there were no differences in terms of cell frequencies of SPBS between HIV and HC, the groups were distinguishable based upon gene expression analyses. Indeed, a 28-gene signature, characterized by higher expression of genes involved in the inflammatory response and immune activation was observed in activated memory B cells (CD27 + CD21 - ) from HIV when compared to HC despite long-term viral control (>24 months). Further analysis, taking into account H1N1 responses after TIV in HIV participants, revealed that a 25-gene signature in resting memory (RM) B cells (CD27 + CD21 + ) was able to distinguish vaccine responders from non-responders (NR). In fact, prevaccination RM B cells of responders showed a higher expression of gene sets involved in B cell adaptive immune responses ( APRIL, BTK, BLIMP1 ) and BCR signaling ( MTOR, FYN, CD86 ) when compared to NR. Overall, these data suggest that a perturbation at a transcriptional level in the B cell compartment persists despite stable virus control achieved through ART in HIV-infected children. Additionally, the present study demonstrates the potential utility of transcriptional evaluation of RM B cells before vaccination for identifying predictive correlates of vaccine responses in this population.

Perturbation of B Cell Gene Expression Persists in HIV-Infected Children Despite Effective Antiretroviral Therapy and Predicts H1N1 Response

PubMed Central

Cotugno, Nicola; De Armas, Lesley; Pallikkuth, Suresh; Rinaldi, Stefano; Issac, Biju; Cagigi, Alberto; Rossi, Paolo; Palma, Paolo; Pahwa, Savita

2017-01-01

Despite effective antiretroviral therapy (ART), HIV-infected individuals with apparently similar clinical and immunological characteristics can vary in responsiveness to vaccinations. However, molecular mechanisms responsible for such impairment, as well as biomarkers able to predict vaccine responsiveness in HIV-infected children, remain unknown. Following the hypothesis that a B cell qualitative impairment persists in HIV-infected children (HIV) despite effective ART and phenotypic B cell immune reconstitution, the aim of the current study was to investigate B cell gene expression of HIV compared to age-matched healthy controls (HCs) and to determine whether distinct gene expression patterns could predict the ability to respond to influenza vaccine. To do so, we analyzed prevaccination transcriptional levels of a 96-gene panel in equal numbers of sort-purified B cell subsets (SPBS) isolated from peripheral blood mononuclear cells using multiplexed RT-PCR. Immune responses to H1N1 antigen were determined by hemaglutination inhibition and memory B cell ELISpot assays following trivalent-inactivated influenza vaccination (TIV) for all study participants. Although there were no differences in terms of cell frequencies of SPBS between HIV and HC, the groups were distinguishable based upon gene expression analyses. Indeed, a 28-gene signature, characterized by higher expression of genes involved in the inflammatory response and immune activation was observed in activated memory B cells (CD27+CD21−) from HIV when compared to HC despite long-term viral control (>24 months). Further analysis, taking into account H1N1 responses after TIV in HIV participants, revealed that a 25-gene signature in resting memory (RM) B cells (CD27+CD21+) was able to distinguish vaccine responders from non-responders (NR). In fact, prevaccination RM B cells of responders showed a higher expression of gene sets involved in B cell adaptive immune responses (APRIL, BTK, BLIMP1) and BCR signaling (MTOR, FYN, CD86) when compared to NR. Overall, these data suggest that a perturbation at a transcriptional level in the B cell compartment persists despite stable virus control achieved through ART in HIV-infected children. Additionally, the present study demonstrates the potential utility of transcriptional evaluation of RM B cells before vaccination for identifying predictive correlates of vaccine responses in this population. PMID:28955330

Anthelmintic drug niclosamide enhances the sensitivity of chronic myeloid leukemia cells to dasatinib through inhibiting Erk/Mnk1/eIF4E pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Zhong; Li, Yong; Lv, Cao

Chronic myeloid leukemia (CML) responds well to BCR-ABL tyrosine kinase inhibitors (TKI), but becomes resistant to TKIs after it progresses to blast phase (BP). Here we show that niclosamide, a FDA-approved anthelmintic drug, enhances the sensitivity of BP-CML cells to dasatinib (2nd generation of BCR-ABL TKI) through inhibiting Erk/Mnk1/eIF4E signaling pathway. Niclosamide dose-dependently inhibits proliferation and induces apoptosis in a panel of CML cell lines. It also selectively targets BP-CML CD34 stem/progenitor cells through inducing apoptosis, inhibiting colony formation and self-renewal capacity while sparing normal bone marrow (NBM) counterparts. In addition, combination of niclosamide and dasatinib is synergistic in CMLmore » cell lines and BP-CML CD34 cells. Importantly, niclosamide inhibits phosphorylation of Erk, Mnk1 and eIF4E in CML cells. Overexpression of phosphomimetic but not nonphosphorylatable form of eIF4E reverses the inhibitory effects of niclosamide, suggesting that eIF4E inhibition is required for the action of niclosamide in CML. Compared to NBM, the increased levels of eIF4E and its activity in CML CD34 cells might explain the selective toxicity of niclosamide in CML versus NBM. We further show that dasatinib time-dependently induces eIF4E phosphorylation. The combination of eIF4E depletion and dasatinib results in similar effects as the combination of niclosamide and dasatinib, suggesting that niclosamide enhances dasatinib through targeting eIF4E. Our work is the first to demonstrate that niclosamide is a potential drug to overcome resistance to BCR-ABL TKI treatment in BP-CML. Our findings also suggest the therapeutic value of Erk/Mnk/eIF4E in CML treatment.« less

Treatment-Free Remission After Second-Line Nilotinib Treatment in Patients With Chronic Myeloid Leukemia in Chronic Phase: Results From a Single-Group, Phase 2, Open-Label Study.

PubMed

Mahon, François-Xavier; Boquimpani, Carla; Kim, Dong-Wook; Benyamini, Noam; Clementino, Nelma Cristina D; Shuvaev, Vasily; Ailawadhi, Sikander; Lipton, Jeffrey Howard; Turkina, Anna G; De Paz, Raquel; Moiraghi, Beatriz; Nicolini, Franck E; Dengler, Jolanta; Sacha, Tomasz; Takahashi, Naoto; Fellague-Chebra, Rafik; Acharya, Sandip; Wong, Stephane; Jin, Yu; Hughes, Timothy P

2018-04-03

Treatment-free remission (TFR)-that is, stopping tyrosine kinase inhibitor (TKI) therapy without loss of response-is an emerging treatment goal in chronic myeloid leukemia (CML). To evaluate TFR after discontinuation of second-line nilotinib therapy. Single-group, phase 2, open-label study. (ClinicalTrials.gov: NCT01698905). 63 centers in 18 countries. Adults with CML in chronic phase who received TKI therapy for at least 3 years (>4 weeks with imatinib, then ≥2 years with nilotinib) and achieved MR4.5 (BCR-ABL1 ≤0.0032% on the International Scale [BCR-ABL1IS]) while receiving nilotinib entered a 1-year consolidation phase. Those with sustained MR4.5 during consolidation were eligible to enter TFR. Patients received nilotinib during consolidation; those who entered TFR stopped treatment. Patients with loss of major molecular response (MMR) (BCR-ABL1IS ≤0.1%) or confirmed loss of MR4 (BCR-ABL1IS ≤0.01%) during TFR reinitiated nilotinib treatment. Proportion of patients without loss of MMR, confirmed loss of MR4, or treatment reinitiation within 48 weeks of stopping treatment (primary end point). 163 patients who had switched from imatinib to nilotinib (for reasons including resistance, intolerance, and physician preference) enrolled in the study and entered the consolidation phase. Of these patients, 126 met the criteria for entering the TFR phase, and 73 (58% [95% CI, 49% to 67%]) and 67 (53% [CI, 44% to 62%]) maintained TFR at 48 weeks (primary end point) and 96 weeks, respectively. Of the 56 patients who reinitiated nilotinib therapy, 55 regained MMR or better and 52 regained MR4.5. None had CML progression to accelerated phase or blast crisis. Musculoskeletal pain was more frequent during the first 48 weeks after nilotinib discontinuation. The study included a heterogeneous patient population and was not designed to compare outcomes between patients continuing and those stopping treatment. TFR seems achievable in patients with sustained MR4.5 after switching to nilotinib. Novartis Pharmaceuticals Corporation.

Discovery of 5-(arenethynyl) hetero-monocyclic derivatives as potent inhibitors of BCR-ABL including the T315I gatekeeper mutant.

PubMed

Thomas, Mathew; Huang, Wei-Sheng; Wen, David; Zhu, Xiaotian; Wang, Yihan; Metcalf, Chester A; Liu, Shuangying; Chen, Ingrid; Romero, Jan; Zou, Dong; Sundaramoorthi, Raji; Li, Feng; Qi, Jiwei; Cai, Lisi; Zhou, Tianjun; Commodore, Lois; Xu, Qihong; Keats, Jeff; Wang, Frank; Wardwell, Scott; Ning, Yaoyu; Snodgrass, Joseph T; Broudy, Marc I; Russian, Karin; Iuliucci, John; Rivera, Victor M; Sawyer, Tomi K; Dalgarno, David C; Clackson, Tim; Shakespeare, William C

2011-06-15

Ponatinib (AP24534) was previously identified as a pan-BCR-ABL inhibitor that potently inhibits the T315I gatekeeper mutant, and has advanced into clinical development for the treatment of refractory or resistant CML. In this study, we explored a novel series of five and six membered monocycles as alternate hinge-binding templates to replace the 6,5-fused imidazopyridazine core of ponatinib. Like ponatinib, these monocycles are tethered to pendant toluanilides via an ethynyl linker. Several compounds in this series displayed excellent in vitro potency against both native BCR-ABL and the T315I mutant. Notably, a subset of inhibitors exhibited desirable PK and were orally active in a mouse model of T315I-driven CML. Copyright © 2011 Elsevier Ltd. All rights reserved.

Determination of cDNA encoding BCR/ABL fusion gene in patients with chronic myelogenous leukemia using a novel FRET-based quantum dots-DNA nanosensor.

PubMed

Shamsipur, Mojtaba; Nasirian, Vahid; Barati, Ali; Mansouri, Kamran; Vaisi-Raygani, Asad; Kashanian, Soheila

2017-05-08

In the present study, we developed a sensitive method based on fluorescence resonance energy transfer (FRET) for the determination of the BCR/ABL fusion gene, which is used as a biomarker to confirm the clinical diagnosis of both chronic myelogenous leukemia (CML) and acute lymphocytic leukemia (ALL). For this purpose, CdTe quantum dots (QDs) were conjugated to amino-modified 18-mer oligonucleotide ((N)DNA) to form the QDs-(N)DNA nanosensor. In the presence of methylene blue (MB) as an intercalator, the hybridization of QDs-(N)DNA with the target BCR/ABL fusion gene (complementary DNA), brings the MB (acceptor) at close proximity of the QDs (donor), leading to FRET upon photoexcitation of the QDs. The enhancement in the emission intensity of MB was used to follow up the hybridization, which was linearly proportional to concentration of the target complementary DNA in a range from 1.0 × 10 -9 to 1.25 × 10 -7  M. The detection limit of the proposed method was obtained to be 1.5 × 10 -10  M. Finally, the feasibility and selectivity of the proposed nanosensor was evaluated by the analysis of derived nucleotides from both mismatched sequences and clinical samples of patients with leukemia as real samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular genetic tests for JAK2V617F, Exon12_JAK2 and MPLW515K/L are highly informative in the evaluation of patients suspected to have BCR-ABL1-negative myeloproliferative neoplasms.

PubMed

dos Santos, Marcos Tadeu; Mitne-Neto, Miguel; Miyashiro, Kozue; Chauffaille, Maria de Lourdes L Ferrari; Rizzatti, Edgar Gil

2014-02-01

Polycythaemia vera (PV), essential thrombocythemia (ET) and idiopathic myelofibrosis (MF), are the most common myeloproliferative neoplasms (MPN) in patients without the BCR-ABL1 gene rearrangement. They are caused by clonal expansion of haematopoietic stem cells and share, as a diagnostic criterion, the identification of JAK2V617F mutation. Classically, when other clinical criteria are present, a JAK2V617F negative case requires the analysis of Exon12_JAK2 for the diagnosis of PV, and of MPL515K/L mutations for the diagnosis of ET and MF. Here, we evaluated 78 samples from Brazilian patients suspected to have MPN, without stratification for PV, ET or MF. We found that 28 (35.9%) are JAK2V617F carriers; from the 50 remaining samples, one (2%) showed an Exon12_JAK2 mutation, and another (2%) was positive for MPLW515L mutation. In summary, the investigation of JAK2V617F, Exon12_JAK2 and MPLW515K/L was relevant for the diagnosis of 38.4% of patients suspected to have BCR-ABL1-negative MPN, suggesting that molecular genetic tests are useful for a quick and unequivocal diagnosis of MPN.

Molecular genetic tests for JAK2V617F, Exon12_JAK2 and MPLW515K/L are highly informative in the evaluation of patients suspected to have BCR-ABL1-negative myeloproliferative neoplasms

PubMed Central

dos Santos, Marcos Tadeu; Mitne-Neto, Miguel; Miyashiro, Kozue; Chauffaille, Maria de Lourdes L Ferrari; Rizzatti, Edgar Gil

2014-01-01

Polycythaemia vera (PV), essential thrombocythemia (ET) and idiopathic myelofibrosis (MF), are the most common myeloproliferative neoplasms (MPN) in patients without the BCR-ABL1 gene rearrangement. They are caused by clonal expansion of haematopoietic stem cells and share, as a diagnostic criterion, the identification of JAK2V617F mutation. Classically, when other clinical criteria are present, a JAK2V617F negative case requires the analysis of Exon12_JAK2 for the diagnosis of PV, and of MPL515K/L mutations for the diagnosis of ET and MF. Here, we evaluated 78 samples from Brazilian patients suspected to have MPN, without stratification for PV, ET or MF. We found that 28 (35.9%) are JAK2V617F carriers; from the 50 remaining samples, one (2%) showed an Exon12_JAK2 mutation, and another (2%) was positive for MPLW515L mutation. In summary, the investigation of JAK2V617F, Exon12_JAK2 and MPLW515K/L was relevant for the diagnosis of 38.4% of patients suspected to have BCR-ABL1-negative MPN, suggesting that molecular genetic tests are useful for a quick and unequivocal diagnosis of MPN. PMID:23986553

Choosing the best treatment strategy for chronic myeloid leukemia patients resistant to imatinib: weighing the efficacy and safety of individual drugs with BCR-ABL mutations and patient history.

PubMed

Jabbour, E; Hochhaus, A; Cortes, J; La Rosée, P; Kantarjian, H M

2010-01-01

For patients with chronic myeloid leukemia who become or are inherently resistant to imatinib therapy, including dose escalation, several important factors must be considered when deciding which strategy to attempt next. The second-generation tyrosine kinase inhibitors (TKIs) dasatinib and nilotinib offer improved potency and a high likelihood of success for these patients. Overall, the efficacy data are comparable for these two agents, and so physicians should consider the BCR-ABL mutation profile and the patient's history to make an educated decision on the best choice. Only a few BCR-ABL mutations seem to be less responsive to either nilotinib or dasatinib and it is recommended to choose the second-line TKI that has shown clinical activity against the specific mutation in these cases. For patients with all other mutations, and for patients with no mutations, it is recommended to choose the second-generation TKI based on the patient's disease history. It is important to choose an agent that minimizes the likelihood of exacerbating the patient's past tolerability issues to imatinib, or comorbid conditions. Here, we propose a treatment algorithm for imatinib-resistant patients based on BCR-ABL mutation status and patient history.

The flavonoid tangeretin activates the unfolded protein response and synergizes with imatinib in the erythroleukemia cell line K562.

PubMed

Lust, Sofie; Vanhoecke, Barbara; Van Gele, Mireille; Philippé, Jan; Bracke, Marc; Offner, Fritz

2010-06-01

We explored the mechanism of cell death of the polymethoxyflavone tangeretin (TAN) in K562 breakpoint cluster region-abelson murine leukemia (Bcr-Abl+) cells. Flow cytometric analysis showed that TAN arrested the cells in the G(2)/M phase and stimulated an accumulation of the cells in the sub-G(0) phase. TAN-induced cell death was evidenced by poly(ADP)-ribose polymerase cleavage, DNA laddering fragmentation, activation of the caspase cascade and downregulation of the antiapoptotic proteins Mcl-1 and Bcl-x(L). Pretreatment with the pancaspase inhibitor Z-VAD-FMK_blocked caspase activation and cell cycle arrest but did not inhibit apoptosis which suggest that other cell killing mechanisms like endoplasmic reticulum (ER)-associated cell death pathways could be involved. We demonstrated that TAN-induced apoptosis was preceded by a rapid activation of the proapoptotic arm of the unfolded protein response, namely PKR-like ER kinase. This was accompanied by enhanced levels of glucose-regulated protein of 78 kDa and of spliced X-box binding protein 1. Furthermore, TAN sensitized K562 cells to the cell killing effects of imatinib via an apoptotic mechanism. In conclusion, our results suggest that TAN is able to induce apoptosis in Bcr-Abl+ cells via cell cycle arrest and the induction of the unfolded protein response, and has synergistic cytotoxicity with imatinib.

Contribution of Protein Tyrosine Phosphateses to the Ontogeny and Progression of Chronic Myeloid Leukemia

DTIC Science & Technology

2006-04-01

activates STATs. The protein tyrosine phosphatases TC-PTP and PTP1B are negative regulators of JAK/STAT signaling molecules and it is possible that...these two PTPs could impede the ability of CML cells to survive and proliferate in response to p210 BCR-Abl. We examined the role of TC-PTP and PTP1b in...contributing to the CML phenotype and found that in some CML cell lines the levels of TC-PTP and PTP1b is increased suggesting that they may be

Electrochemical Branched-DNA Assay for Polymerase Chain Reaction-Free Detection and Quantification of Oncogenes in Messenger RNA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Ai Cheng; Dai, Ziyu; Chen, Baowei

2008-12-01

We describe a novel electrochemical branched-DNA (bDNA) assay for polymerase chain reaction (PCR)-free detection and quantification of p185 BCR-ABL leukemia fusion transcript in the population of messenger RNA (mRNA) extracted from cell lines. The bDNA amplifier carrying high loading of alkaline phosphatase (ALP) tracers was used to amplify targets signal. The targets were captured on microplate well surfaces through cooperative sandwich hybridization prior to the labeling of bDNA. The activity of captured ALP was monitored by square-wave voltammetric (SWV) analysis of the electroactive enzymatic product in the presence of 1-napthyl-phosphate. The specificity and sensitivity of assay enabled direct detection ofmore » target transcript in as little as 4.6 ng mRNA without PCR amplification. In combination with the use of a well-quantified standard, the electrochemical bDNA assay was capable of direct use for a PCR-free quantitative analysis of target transcript in total mRNA population. The approach thus provides a simple, sensitive, accurate and quantitative tool alternate to the RQ-PCR for early disease diagnosis.« less

Temsirolimus and Imatinib Mesylate in Treating Patients With Chronic Myelogenous Leukemia

ClinicalTrials.gov

2013-01-11

Accelerated Phase Chronic Myelogenous Leukemia; Blastic Phase Chronic Myelogenous Leukemia; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Chronic Phase Chronic Myelogenous Leukemia; Relapsing Chronic Myelogenous Leukemia

Interferon-α Based Individualized Treatment of a High Risk Chronic Myelogenous Leukemia Patient Harboring T315I Mutation.

PubMed

Zeng, Yunxin; Zhang, Jingwen; Li, Xiaoqing; Zhang, Ling; Liu, Jiajun

2018-06-01

T315I mutation is the most common BCR-ABL mutation and confers resistance to all the first and second generation BCR-ABL tyrosine kinases, including nilotinib and dasatinib. We report a high risk chronic myelogenous leukemia (CML) patient harboring the T315I mutation treated by Interferon-α (INF-α) solo and subsequently combined with dasatinib. Hematological investigation, bone marrow cytology inspection, chromosomal analysis (G-banding), and real-time quantitative polymerase chain reaction (RQ-PCR) were performed on a 47-year-old male patient. After 8 months IFN-α monotherapy, the patient lost the T315I mutation but acquired a new F359V mutation. After 2 months on dasatinib and INF-α treatment, the patient achieved complete hematologic response (CHR). IFN-α based combination therapy could be a viable treatment option for CML patients harboring T315I BCR-ABL mutation.

A screen to identify drug resistant variants to target-directed anti-cancer agents

PubMed Central

Azam, Mohammad; Raz, Tal; Nardi, Valentina; Opitz, Sarah L.

2003-01-01

The discovery of oncogenes and signal transduction pathways important for mitogenesis has triggered the development of target-specific small molecule anti-cancer compounds. As exemplified by imatinib (Gleevec), a specific inhibitor of the Chronic Myeloid Leukemia (CML)-associated Bcr-Abl kinase, these agents promise impressive activity in clinical trials, with low levels of clinical toxicity. However, such therapy is susceptible to the emergence of drug resistance due to amino acid substitutions in the target protein. Defining the spectrum of such mutations is important for patient monitoring and the design of next-generation inhibitors. Using imatinib and BCR/ABL as a paradigm for a drug-target pair, we recently reported a retroviral vector-based screening strategy to identify the spectrum of resistance-conferring mutations. Here we provide a detailed methodology for the screen, which can be generally applied to any drug-target pair. PMID:14615817

Tyrosine Kinase Inhibitor Treatment for Newly Diagnosed Chronic Myeloid Leukemia.

PubMed

Radich, Jerald P; Mauro, Michael J

2017-08-01

Chronic myeloid leukemia (CML) is a myeloproliferative disorder that accounts for approximately 10% of new cases of leukemia. The introduction of tyrosine kinase inhibitors has led to a reduction in mortalities. Thus, the estimated prevalence of CML is increasing. The National Comprehensive Cancer Network and the European Leukemia Net guidelines incorporate frequent molecular monitoring of the fusion BCR-ABL transcript to ensure that patients reach and keep treatment milestones. Most patients with CML are diagnosed in the chronic phase, and approximately 10% to 30% of these patients will at some time in their course meet definition criteria of resistance to imatinib. Copyright © 2017 Elsevier Inc. All rights reserved.

Chronic myelogenous leukemia in eastern Pennsylvania: an assessment of registry reporting.

PubMed

Mertz, Kristen J; Buchanich, Jeanine M; Washington, Terri L; Irvin-Barnwell, Elizabeth A; Woytowitz, Donald V; Smith, Roy E

2015-01-01

Chronic myelogenous leukemia (CML) has been reportable to the Pennsylvania Cancer Registry (PCR) since the 1980s, but the completeness of reporting is unknown. This study assessed CML reporting in eastern Pennsylvania where a cluster of another myeloproliferative neoplasm was previously identified. Cases were identified from 2 sources: 1) PCR case reports for residents of Carbon, Luzerne, or Schuylkill County with International Classification of Diseases for Oncology, Third Edition (ICD-O-3) codes 9875 (CML, BCR-ABL+), 9863 (CML, NOS), and 9860 (myeloid leukemia) and date of diagnosis 2001-2009, and 2) review of billing records at hematology practices. Participants were interviewed and their medical records were reviewed by board-certified hematologists. PCR reports included 99 cases coded 9875 or 9863 and 9 cases coded 9860; 2 additional cases were identified by review of billing records. Of the 110 identified cases, 93 were mailed consent forms, 23 consented, and 12 medical records were reviewed. Hematologists confirmed 11 of 12 reviewed cases as CML cases; all 11 confirmed cases were BCR/ABL positive, but only 1 was coded as positive (code 9875). Very few unreported CML cases were identified, suggesting relatively complete reporting to the PCR. Cases reviewed were accurately diagnosed, but ICD-0-3 coding often did not reflect BCR-ABL-positive tests. Cancer registry abstracters should look for these test results and code accordingly.

Silencing of BCR/ABL Chimeric Gene in Human Chronic Myelogenous Leukemia Cell Line K562 by siRNA-Nuclear Export Signal Peptide Conjugates.

PubMed

Shinkai, Yasuhiro; Kashihara, Shinichi; Minematsu, Go; Fujii, Hirofumi; Naemura, Madoka; Kotake, Yojiro; Morita, Yasutaka; Ohnuki, Koichiro; Fokina, Alesya A; Stetsenko, Dmitry A; Filichev, Vyacheslav V; Fujii, Masayuki

2017-06-01

Herein we described the synthesis of siRNA-NES (nuclear export signal) peptide conjugates by solid phase fragment coupling and the application of them to silencing of bcr/abl chimeric gene in human chronic myelogenous leukemia cell line K562. Two types of siRNA-NES conjugates were prepared, and both sense strands at 5' ends were covalently linked to a NES peptide derived from TFIIIA and HIV-1 REV, respectively. Significant enhancement of silencing efficiency was observed for both of them. siRNA-TFIIIA NES conjugate suppressed the expression of BCR/ABL gene to 8.3% at 200 nM and 11.6% at 50 nM, and siRNA-HIV-1REV NES conjugate suppressed to 4.0% at 200 nM and 6.3% at 50 nM, whereas native siRNA suppressed to 36.3% at 200 nM and 30.2% at 50 nM. We could also show complex of siRNA-NES conjugate and designed amphiphilic peptide peptideβ7 could be taken up into cells with no cytotoxicity and showed excellent silencing efficiency. We believe that the complex siRNA-NES conjugate and peptideβ7 is a promising candidate for in vivo use and therapeutic applications.

BCR-ABL1: Test

MedlinePlus

... Acid-Fast Bacillus (AFB) Testing Activated Clotting Time Acute Viral Hepatitis Panel Adenosine Deaminase Adrenocorticotropic Hormone (ACTH) ... Guillain-Barré Syndrome Hashimoto Thyroiditis Heart Attack and Acute Coronary Syndrome Heart Disease Hemochromatosis Hemoglobin Abnormalities Hepatitis ...

Combinations of Novel Histone Deacetylase and Bcr-Abl Inhibitors in the Therapy of Imatinib Mesylate-Sensitive and -Refractory Bcr-Abl Expressing Leukemia

DTIC Science & Technology

2008-12-01

information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services , Directorate for Information Operations... internal tandem duplications pro- mote cell viability and proliferation by signaling through Foxo proteins. Oncogene. 2004;23:3338- 3349. 45. Harada H...Chronic myelogenous leukemia: biology and therapy. Ann Intern Med 1999; 131:207-19. Kantarjian HM, Dixon D, Keating MJ, et al. Characteristics of

miR-17-92 promotes leukemogenesis in chronic myeloid leukemia via targeting A20 and activation of NF-κB signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jia, Qinghua; Sun, Huiyan; Xiao, Fengjun

miR-17-92 cluster are overexpressed in hematological malignancies including chronic myeloid leukemia (CML). However, their roles and mechanisms that regulate BCR-ABL induced leukemogenesis remain unclear. In this study, we demonstrated that genomic depletion of miR-17-92 inhibited the BCR-ABL induced leukemogenesis by using a mouse model of transplantation of BCR-ABL transduced hematopoietic stem cells. Furthermore, we identified that miR-19b targeted A20 (TNFAIP3). A20 overexpression results in inactivation of NF-κB activity including decrease of phosphorylation of P65 and IκBα, leads to induce apoptosis and inhibit proliferation and cycle in CML CD34 {sup +} cells. Thus we proved that miR-17-92 is a critical contributor to CMLmore » leukemogenesis via targeting A20 and activation of NF-κB signaling. These findings indicate that miR-17-92 will be important resources for developing novel treatment strategies of CML and better understanding long-term disease control. - Highlights: • Genomic depletion of miR-17-92 inhibits the BCR-ABL induced leukemogenesis in a mouse CML model. • miR-19b targets A20 to regulate NF-κB signaling in CML cells. • A20 functions as a suppressor in regulating CML cell growth and survival.« less

[Development of Ph negative acute myeloid leukemia in a patient with minor-BCR/ABL positive chronic myeloid leukemia achieving a partial cytogenetic response during tyrosine kinase inhibitor treatment].

PubMed

Fujii, Soichiro; Miura, Ikuo; Tanaka, Hideo

2015-06-01

A 78-year-old male, who had CKD and chronic heart failure, was referred to our hospital for evaluation of leukocytosis. His bone marrow contained 12% blast cells and chromosome analysis showed the Ph chromosome as well as other changes. The patient was diagnosed with the accelerated-phase CML because FISH and RT-PCR disclosed BCR/ABL fusion signals and minor BCR/ABL, respectively. Imatinib was administered, but the CML was resistant to this treatment. We gave him nilotinib employing a reduced and intermittent administration protocol because of the progression of anemia and heart failure. The patient achieved PCyR in 8 months, but, 12 months later, his WBC count increased and 83% of the cells were blasts. Because the probable diagnosis was the blast crisis of CML, we switched from nilotinib to dasatinib. However, leukocytosis worsened and he died of pneumonia. It was later revealed that he had a normal karyotype and both FISH and RT-PCR analysis of BCR/ABL were negative. His final diagnosis was Ph negative AML developing from Ph positive CML in PCyR. Since there were no dysplastic changes indicative of MDS, it was assumed that the AML was not secondary leukemia caused by the tyrosine kinase inhibitor but, rather, de novo AML.

Regulation of B cell functions by the sialic acid-binding receptors siglec-G and CD22.

PubMed

Jellusova, Julia; Nitschke, Lars

2011-01-01

B cell antigen receptor (BCR) engagement can lead to many different physiologic outcomes. To achieve an appropriate response, the BCR signal is interpreted in the context of other stimuli and several additional receptors on the B cell surface participate in the modulation of the signal. Two members of the Siglec (sialic acid-binding immunoglobulin-like lectin) family, CD22 and Siglec-G have been shown to inhibit the BCR signal. Recent findings indicate that the ability of these two receptors to bind sialic acids might be important to induce tolerance to self-antigens. Sialylated glycans are usually absent on microbes but abundant in higher vertebrates and might therefore provide an important tolerogenic signal. Since the expression of the specific ligands for Siglec-G and CD22 is tightly regulated and since Siglecs are not only able to bind their ligands in trans but also on the same cell surface this might provide additional mechanisms to control the BCR signal. Although both Siglec-G and CD22 are expressed on B cells and are able to inhibit BCR mediated signaling, they also show unique biological functions. While CD22 is the dominant regulator of calcium signaling on conventional B2 cells and also seems to play a role on marginal zone B cells, Siglec-G exerts its function mainly on B1 cells and influences their lifespan and antibody production. Both Siglec-G and CD22 have also recently been linked to toll-like receptor signaling and may provide a link in the regulation of the adaptive and innate immune response of B cells.

Aberrant DNA Methylation in Chronic Myeloid Leukemia: Cell Fate Control, Prognosis, and Therapeutic Response.

PubMed

Behzad, Masumeh Maleki; Shahrabi, Saeid; Jaseb, Kaveh; Bertacchini, Jessika; Ketabchi, Neda; Saki, Najmaldin

2018-01-31

Chronic myeloid leukemia (CML) is a hematopoietic stem cell malignancy characterized by the expression of the BCR-ABL1 fusion gene with different chimeric transcripts. Despite the crucial impact of constitutively active tyrosine kinase in CML pathogenesis, aberrant DNA methylation of certain genes plays an important role in disease progression and the development of drug resistance. This article reviews recent findings relevant to the effect of DNA methylation pattern of regulatory genes on various cellular activities such as cell proliferation and survival, as well as cell-signaling molecules in CML. These data might contribute to defining the role of aberrant DNA methylation in disease initiation and progression. However, further studies are needed on the validation of specific aberrant methylation markers regarding the prognosis and prediction of response among the CML patients.

BCR-ABL1 molecular remission after 90Y-epratuzumab tetraxetan radioimmunotherapy in CD22+ Ph+ B-ALL: proof of principle.

PubMed

Chevallier, Patrice; Bodet-Milin, Caroline; Robillard, Nelly; Eugene, Thomas; Menard, Audrey; Le Houerou, Claire; Guillaume, Thierry; Delaunay, Jacques; Escoffre-Barbe, Martine; Wegener, William A; Goldenberg, David M; Kraeber-Bodéré, Francoise

2013-12-01

Although targeted therapies are used increasingly in hematologic malignancies, we are unaware of any prior studies of radioimmunotherapy (RAIT) in B-acute lymphoblastic leukemia (ALL), even though this radiosensitive tumor expresses CD22, potentially a good target for this approach. Here, we report a patient with Philadelphia chromosome-positive B-ALL in third relapse who received RAIT with (90) yttrium ((90) Y)-labeled anti-CD22 epratuzumab tetraxetan. Seven weeks after initiating therapy, the patient achieved a BCR-ABL1 molecular remission documented by RT-qPCR, which is now continuing at 6 months while awaiting an allogeneic hematopoietic stem cell transplant. (90) Y-Epratuzumab tetraxetan may be a promising therapeutic option for CD22(+) B-ALL patients. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

miR-29b suppresses CML cell proliferation and induces apoptosis via regulation of BCR/ABL1 protein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yajuan; Wang, Haixia; Tao, Kun

MicroRNAs (miRNAs) are small RNAs that regulate gene expression posttranscriptionally and are critical for many cellular pathways. Recent evidence has shown that aberrant miRNA expression profiles and unique miRNA signaling pathways are present in many cancers. Here, we demonstrate that miR-29b is markedly lower expressed in CML patient samples. Bioinformatics analysis reveals a conserved target site for miR-29b in the 3′-untranslated region (UTR) of ABL1. miR-29b significantly suppresses the activity of a luciferase reporter containing ABL1-3′UTR and this activity is not observed in cells transfected with mutated ABL1-3′UTR. Enforced expression of miR-29b in K562 cells inhibits cell growth and colonymore » formation ability thereby inducing apoptosis through cleavage of procaspase 3 and PARP. Furthermore, K562 cells transfected with a siRNA targeting ABL1 show similar growth and apoptosis phenotypes as cells overexpression of miR-29b. Collectively, our results suggest that miR-29b may function as a tumor suppressor by targeting ABL1 and BCR/ABL1. - Highlights: ► miR-29b expression was downregulated in CML patients. ► ABL1 was identified as a direct target gene of miR-29b. ► Enforced expression of miR-29b inhibits cell proliferation and induces apoptosis. ► miR-29b might be a therapeutic target to CML.« less

Molecular drug targets in myeloproliferative neoplasms: mutant ABL1, JAK2, MPL, KIT, PDGFRA, PDGFRB and FGFR1

PubMed Central

Tefferi, Ayalew

2009-01-01

Abstract Therapeutically validated oncoproteins in myeloproliferative neoplasms (MPN) include BCR-ABL1 and rearranged PDGFR proteins. The latter are products of intra- (e.g. FIP1L1-PDGFRA) or inter-chromosomal (e.g.ETV6-PDGFRB) gene fusions. BCR-ABL1 is associated with chronic myelogenous leukaemia (CML) and mutant PDGFR with an MPN phenotype characterized by eosinophilia and in addition, in case of FIP1L1-PDGFRA, bone marrow mastocytosis. These genotype-phenotype associations have been effectively exploited in the development of highly accurate diagnostic assays and molecular targeted therapy. It is hoped that the same will happen in other MPN with specific genetic alterations: polycythemia vera (JAK2V617F and other JAK2 mutations), essential thrombocythemia (JAK2V617F and MPL515 mutations), primary myelofibrosis (JAK2V617F and MPL515 mutations), systemic mastocytosis (KITD816V and other KIT mutations) and stem cell leukaemia/lymphoma (ZNF198-FGFR1 and other FGFR1 fusion genes). The current review discusses the above-listed mutant molecules in the context of their value as drug targets. PMID:19175693

Biosensing of BCR/ABL fusion gene using an intensity-interrogation surface plasmon resonance imaging system

NASA Astrophysics Data System (ADS)

Wu, Jiangling; Huang, Yu; Bian, Xintong; Li, DanDan; Cheng, Quan; Ding, Shijia

2016-10-01

In this work, a custom-made intensity-interrogation surface plasmon resonance imaging (SPRi) system has been developed to directly detect a specific sequence of BCR/ABL fusion gene in chronic myelogenous leukemia (CML). The variation in the reflected light intensity detected from the sensor chip composed of gold islands array is proportional to the change of refractive index due to the selective hybridization of surface-bound DNA probes with target ssDNA. SPRi measurements were performed with different concentrations of synthetic target DNA sequence. The calibration curve of synthetic target sequence shows a good relationship between the concentration of synthetic target and the change of reflected light intensity. The detection limit of this SPRi measurement could approach 10.29 nM. By comparing SPRi images, the target ssDNA and non-complementary DNA sequence are able to be distinguished. This SPRi system has been applied for assay of BCR/ABL fusion gene extracted from real samples. This nucleic acid-based SPRi biosensor therefore offers an alternative high-effective, high-throughput label-free tool for DNA detection in biomedical research and molecular diagnosis.

Clonal Evolution and Blast Crisis Correlate with Enhanced Proteolytic Activity of Separase in BCR-ABL b3a2 Fusion Type CML under Imatinib Therapy.

PubMed

Haaß, Wiltrud; Kleiner, Helga; Weiß, Christel; Haferlach, Claudia; Schlegelberger, Brigitte; Müller, Martin C; Hehlmann, Rüdiger; Hofmann, Wolf-Karsten; Fabarius, Alice; Seifarth, Wolfgang

2015-01-01

Unbalanced (major route) additional cytogenetic aberrations (ACA) at diagnosis of chronic myeloid leukemia (CML) indicate an increased risk of progression and shorter survival. Moreover, newly arising ACA under imatinib treatment and clonal evolution are considered features of acceleration and define failure of therapy according to the European LeukemiaNet (ELN) recommendations. On the basis of 1151 Philadelphia chromosome positive chronic phase patients of the randomized CML-study IV, we examined the incidence of newly arising ACA under imatinib treatment with regard to the p210BCR-ABL breakpoint variants b2a2 and b3a2. We found a preferential acquisition of unbalanced ACA in patients with b3a2 vs. b2a2 fusion type (ratio: 6.3 vs. 1.6, p = 0.0246) concurring with a faster progress to blast crisis for b3a2 patients (p = 0.0124). ESPL1/Separase, a cysteine endopeptidase, is a key player in chromosomal segregation during mitosis. Separase overexpression and/or hyperactivity has been reported from a wide range of cancers and cause defective mitotic spindles, chromosome missegregation and aneuploidy. We investigated the influence of p210BCR-ABL breakpoint variants and imatinib treatment on expression and proteolytic activity of Separase as measured with a specific fluorogenic assay on CML cell lines (b2a2: KCL-22, BV-173; b3a2: K562, LAMA-84). Despite a drop in Separase protein levels an up to 5.4-fold increase of Separase activity under imatinib treatment was observed exclusively in b3a2 but not in b2a2 cell lines. Mimicking the influence of imatinib on BV-173 and LAMA-84 cells by ESPL1 silencing stimulated Separase proteolytic activity in both b3a2 and b2a2 cell lines. Our data suggest the existence of a fusion type-related feedback mechanism that posttranslationally stimulates Separase proteolytic activity after therapy-induced decreases in Separase protein levels. This could render b3a2 CML cells more prone to aneuploidy and clonal evolution than b2a2 progenitors and may therefore explain the cytogenetic results of CML patients.

Comparative Phenotypic Analysis of the Major Fungal Pathogens Candida parapsilosis and Candida albicans

PubMed Central

Holland, Linda M.; Schröder, Markus S.; Turner, Siobhán A.; Taff, Heather; Andes, David; Grózer, Zsuzsanna; Gácser, Attila; Ames, Lauren; Haynes, Ken; Higgins, Desmond G.; Butler, Geraldine

2014-01-01

Candida parapsilosis and Candida albicans are human fungal pathogens that belong to the CTG clade in the Saccharomycotina. In contrast to C. albicans, relatively little is known about the virulence properties of C. parapsilosis, a pathogen particularly associated with infections of premature neonates. We describe here the construction of C. parapsilosis strains carrying double allele deletions of 100 transcription factors, protein kinases and species-specific genes. Two independent deletions were constructed for each target gene. Growth in >40 conditions was tested, including carbon source, temperature, and the presence of antifungal drugs. The phenotypes were compared to C. albicans strains with deletions of orthologous transcription factors. We found that many phenotypes are shared between the two species, such as the role of Upc2 as a regulator of azole resistance, and of CAP1 in the oxidative stress response. Others are unique to one species. For example, Cph2 plays a role in the hypoxic response in C. parapsilosis but not in C. albicans. We found extensive divergence between the biofilm regulators of the two species. We identified seven transcription factors and one protein kinase that are required for biofilm development in C. parapsilosis. Only three (Efg1, Bcr1 and Ace2) have similar effects on C. albicans biofilms, whereas Cph2, Czf1, Gzf3 and Ume6 have major roles in C. parapsilosis only. Two transcription factors (Brg1 and Tec1) with well-characterized roles in biofilm formation in C. albicans do not have the same function in C. parapsilosis. We also compared the transcription profile of C. parapsilosis and C. albicans biofilms. Our analysis suggests the processes shared between the two species are predominantly metabolic, and that Cph2 and Bcr1 are major biofilm regulators in C. parapsilosis. PMID:25233198

Antibodies against CD20 or B-Cell Receptor Induce Similar Transcription Patterns in Human Lymphoma Cell Lines

PubMed Central

Franke, Andreas; Niederfellner, Gerhard J.; Klein, Christian; Burtscher, Helmut

2011-01-01

Background CD20 is a cell surface protein exclusively expressed on B cells. It is a clinically validated target for Non-Hodgkin's lymphomas (NHL) and autoimmune diseases. The B cell receptor (BCR) plays an important role for development and proliferation of pre-B and B cells. Physical interaction of CD20 with BCR and components of the BCR signaling cascade has been reported but the consequences are not fully understood. Methodology In this study we employed antibodies against CD20 and against the BCR to trigger the respective signaling. These antibodies induced very similar expression patterns of up- and down-regulated genes in NHL cell lines indicating that CD20 may play a role in BCR signaling and vice versa. Two of the genes that were rapidly and transiently induced by both stimuli are CCL3 and CCL4. 4 hours after stimulation the concentration of these chemokines in culture medium reaches a maximum. Spleen tyrosine kinase Syk is a cytoplasmic tyrosine kinase and a key component of BCR signaling. Both siRNA mediated silencing of Syk and inhibition by selective small molecule inhibitors impaired CCL3/CCL4 protein induction after treatment with either anti-CD20 or anti-BCR antibodies. Conclusion Our results suggest that treatment with anti-CD20 antibodies triggers at least partially a BCR activation-like response in NHL cell lines. PMID:21364752

Short (≤ 1 mm) positive surgical margin and risk of biochemical recurrence after radical prostatectomy.

PubMed

Shikanov, Sergey; Marchetti, Pablo; Desai, Vikas; Razmaria, Aria; Antic, Tatjana; Al-Ahmadie, Hikmat; Zagaja, Gregory; Eggener, Scott; Brendler, Charles; Shalhav, Arieh

2013-04-01

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: It has been suggested that a very short positive margin does not confer additional risk of BCR after radical prostatectomy. This study shows that even very short PSM is associated with increased risk of BCR. To re-evaluate, in a larger cohort with longer follow-up, our previously reported finding that a positive surgical margin (PSM) ≤ 1 mm may not confer an additional risk for biochemical recurrence (BCR) compared with a negative surgical margin (NSM). Margin status and length were evaluated in 2866 men treated with radical prostatectomy (RP) for clinically localized prostate cancer at our institution from 1994 to 2009. We compared the BCR-free survival probability of men with NSMs, a PSM ≤ 1 mm, and a PSM < 1 mm using the Kaplan-Meier method and a Cox regression model adjusted for preoperative prostate-specific antigen (PSA) level, age, pathological stage and pathological Gleason score (GS). Compared with a NSM, a PSM ≤ 1 mm was associated with 17% lower 3-year BCR-free survival for men with pT3 and GS ≥ 7 tumours and a 6% lower 3-year BCR-free survival for men with pT2 and GS ≤ 6 tumours (log-rank P < 0.001 for all). In the multivariate model, a PSM ≤ 1 mm was associated with a probability of BCR twice as high as that for a NSM (hazard ratio [HR] 2.2), as were a higher PSA level (HR 1.04), higher pathological stage (HR 2.7) and higher pathological GS (HR 3.7 [all P < 0.001]). In men with non-organ-confined or high grade prostate cancer, a PSM ≤ 1 mm has a significant adverse impact on BCR rates. © 2012 The Authors. BJU International © 2012 BJU International.

B-cell receptor signalling and its crosstalk with other pathways in normal and malignant cells.

PubMed

Seda, Vaclav; Mraz, Marek

2015-03-01

The physiology of B cells is intimately connected with the function of their B-cell receptor (BCR). B-cell lymphomas frequently (dys)regulate BCR signalling and thus take advantage of this pre-existing pathway for B-cell proliferation and survival. This has recently been underscored by clinical trials demonstrating that small molecules (fosfamatinib, ibrutinib, idelalisib) inhibiting BCR-associated kinases (SYK, BTK, PI3K) have an encouraging clinical effect. Here we describe the current knowledge of the specific aspects of BCR signalling in diffuse large B-cell lymphoma (DLBCL), follicular lymphoma, chronic lymphocytic leukaemia (CLL) and normal B cells. Multiple factors can contribute to BCR pathway (dys)regulation in these malignancies and the activation of 'chronic' or 'tonic' BCR signalling. In lymphoma B cells, the balance of initiation, amplitude and duration of BCR activation can be influenced by a specific immunoglobulin structure, the expression and mutations of adaptor molecules (like GAB1, BLNK, GRB2, CARD11), the activity of kinases (like LYN, SYK, PI3K) or phosphatases (like SHIP-1, SHP-1 and PTEN) and levels of microRNAs. We also discuss the crosstalk of BCR with other signalling pathways (NF-κB, adhesion through integrins, migration and chemokine signalling) to emphasise that the 'BCR inhibitors' target multiple pathways interconnected with BCR, which might explain some of their clinical activity. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Advances in therapy for Philadelphia-positive acute lymphoblastic leukaemia of childhood and adolescence.

PubMed

Bleckmann, Kirsten; Schrappe, Martin

2016-03-01

The presence of the BCR/ABL1 fusion gene in childhood acute lymphoblastic leukaemia (ALL) is a rare finding and has been an adverse prognostic factor associated with a high risk of therapeutic failure. The current key components of treatment are intensive polychemotherapy and a BCR/ABL1 kinase domain inhibitor. This treatment approach has been applied in a few clinical trials by paediatric leukaemia study groups. Thus, this subtype of ALL serves as the first model system for truly targeted treatment. The role of haematopoietic stem cell transplantation (HSCT) is increasingly called into question, at least in a favourable, though not yet clearly defined, subset of patients. Currently, the choice of the most effective tyrosine kinase inhibitor is not yet settled, in particular, in view of potential reduction of overall treatment intensity. © 2016 John Wiley & Sons Ltd.

Laboratory practice guidelines for detecting and reporting JAK2 and MPL mutations in myeloproliferative neoplasms: a report of the Association for Molecular Pathology.

PubMed

Gong, Jerald Z; Cook, James R; Greiner, Timothy C; Hedvat, Cyrus; Hill, Charles E; Lim, Megan S; Longtine, Janina A; Sabath, Daniel; Wang, Y Lynn

2013-11-01

Recurrent mutations in JAK2 and MPL genes are genetic hallmarks of BCR-ABL1-negative myeloproliferative neoplasms. Detection of JAK2 and MPL mutations has been incorporated into routine diagnostic algorithms for these diseases. This Special Article summarizes results from a nationwide laboratory survey of JAK2 and MPL mutation analysis. Based on the current practice pattern and the literature, this Special Article provides recommendations and guidelines for laboratory practice for detection of mutations in the JAK2 and MPL genes, including clinical manifestations for prompting the mutation analysis, current and recommended methodologies for testing the mutations, and standardization for reporting the test results. This Special Article also points to future directions for genomic testing in BCR-ABL1-negative myeloproliferative neoplasms. Copyright © 2013 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Declining lymphoid progenitor fitness promotes aging-associated leukemogenesis.

PubMed

Henry, Curtis J; Marusyk, Andriy; Zaberezhnyy, Vadym; Adane, Biniam; DeGregori, James

2010-12-14

Aging is associated with the functional decline of cells, tissues, and organs. At the same time, age is the single most important prognostic factor in the development of most human cancers, including chronic myelogenous and acute lymphoblastic leukemias initiated by Bcr-Abl oncogenic translocations. Prevailing paradigms attribute the association between aging and cancers to the accumulation of oncogenic mutations over time, because the accrual of oncogenic events is thought to be the rate-limiting step in initiation and progression of cancers. Conversely, aging-associated functional decline caused by both cell-autonomous and non-cell-autonomous mechanisms is likely to reduce the fitness of stem and progenitor cell populations. This reduction in fitness should be conducive for increased selection of oncogenic mutations that can at least partially alleviate fitness defects, thereby promoting the initiation of cancers. We tested this hypothesis using mouse hematopoietic models. Our studies indicate that the dramatic decline in the fitness of aged B-lymphopoiesis coincides with altered receptor-associated kinase signaling. We further show that Bcr-Abl provides a much greater competitive advantage to old B-lymphoid progenitors compared with young progenitors, coinciding with restored kinase signaling pathways, and that this enhanced competitive advantage translates into increased promotion of Bcr-Abl-driven leukemias. Moreover, impairing IL-7-mediated signaling is sufficient to promote selection for Bcr-Abl-expressing B progenitors. These studies support an unappreciated causative link between aging and cancer: increased selection of oncogenic mutations as a result of age-dependent alterations of the fitness landscape.

A HYPOTHESIS ACCOUNTING FOR THE PARADOXICAL EXPRESSION OF THE D GENE SEGMENT IN THE BCR AND THE TCR

PubMed Central

Cohn, Melvin

2009-01-01

The D gene segment expressed in both the TCR and BCR has a challenging behavior that begs interpretation. It is incorporated in three reading frames in the rearranged transcription unit but is expressed in antigen-selected cells in a preferred frame. Why was it so important to waste 2/3 of newborn cells? The hypothesis is presented that the D region is framework playing a role in both the TCR and the BCR by determining whether a signal is transmitted to the cell upon interaction with a cognate ligand. This assumption operates in determining haplotype exclusion for the BCR and in regulating the signaling orientation for the TCR. Relevant data as well as a definitive experiment challenging the validity of this hypothesis, are discussed. PMID:18546143

Regulation of B Cell Functions by the Sialic Acid-Binding Receptors Siglec-G and CD22

PubMed Central

Jellusova, Julia; Nitschke, Lars

2011-01-01

B cell antigen receptor (BCR) engagement can lead to many different physiologic outcomes. To achieve an appropriate response, the BCR signal is interpreted in the context of other stimuli and several additional receptors on the B cell surface participate in the modulation of the signal. Two members of the Siglec (sialic acid-binding immunoglobulin-like lectin) family, CD22 and Siglec-G have been shown to inhibit the BCR signal. Recent findings indicate that the ability of these two receptors to bind sialic acids might be important to induce tolerance to self-antigens. Sialylated glycans are usually absent on microbes but abundant in higher vertebrates and might therefore provide an important tolerogenic signal. Since the expression of the specific ligands for Siglec-G and CD22 is tightly regulated and since Siglecs are not only able to bind their ligands in trans but also on the same cell surface this might provide additional mechanisms to control the BCR signal. Although both Siglec-G and CD22 are expressed on B cells and are able to inhibit BCR mediated signaling, they also show unique biological functions. While CD22 is the dominant regulator of calcium signaling on conventional B2 cells and also seems to play a role on marginal zone B cells, Siglec-G exerts its function mainly on B1 cells and influences their lifespan and antibody production. Both Siglec-G and CD22 have also recently been linked to toll-like receptor signaling and may provide a link in the regulation of the adaptive and innate immune response of B cells. PMID:22566885

Proposed prognostic scoring system evaluating risk factors for biochemical recurrence of prostate cancer after salvage radiation therapy.

PubMed

Lee, Richard J; Tzou, Katherine S; Heckman, Michael G; Hobbs, Corey J; Rawal, Bhupendra; Diehl, Nancy N; Peterson, Jennifer L; Paryani, Nitesh N; Ko, Stephen J; Daugherty, Larry C; Vallow, Laura A; Wong, William; Schild, Steven; Pisansky, Thomas M; Buskirk, Steven J

2016-08-01

To update a previously proposed prognostic scoring system that predicts risk of biochemical recurrence (BCR) after salvage radiation therapy (SRT) for recurrent prostate cancer when using additional patients and a PSA value of 0.2 ng/mL and rising as the definition of BCR. We included 577 patients who received SRT for a rising PSA after radical prostatectomy in this retrospective cohort study. Clinical, pathological, and SRT characteristics were evaluated for association with BCR using relative risks (RRs) from multivariable Cox regression models. With a median follow-up of 5.5 years after SRT, 354 patients (61%) experienced BCR. At 5 years after SRT, 40% of patients were free of BCR. Independent associations with BCR were identified for the PSA level before SRT (RR [doubling]: 1.25, P < 0.001), pathological tumour stage (RR [T3a vs T2] 1.21, P = 0.19; RR [T3b/T4 vs T2] 2.09, P < 0.001; overall P < 0.001), Gleason score (RR [7 vs <7] 1.63, P < 0.001; RR [8-10 vs <7] 2.28, P < 0.001; overall P < 0.001), and surgical margin status (RR [positive vs negative] 0.71, P = 0.003). We combined these four variables to create a prognostic scoring system that predicted BCR risk with a c-index of 0.66. Scores ranged from 0 to 7, and 5-year freedom from BCR for different levels of the score was as follows: Score = 0-1: 66%, Score = 2: 46%, Score = 3: 28%, Score = 4: 19%, and Score = 5-7: 15%. We developed a scoring system that provides an estimation of the risk of BCR after SRT. These findings will be useful for patients and physicians in decision making for radiation therapy in the salvage setting. © 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.

Tyrosine phosphorylation of 3BP2 is indispensable for the interaction with VAV3 in chicken DT40 cells.

PubMed

Chihara, Kazuyasu; Kimura, Yukihiro; Honjoh, Chisato; Yamauchi, Shota; Takeuchi, Kenji; Sada, Kiyonao

2014-03-10

Adaptor protein c-Abl SH3 domain-binding protein-2 (3BP2) is known to play regulatory roles in immunoreceptor-mediated signal transduction. We have previously demonstrated that Tyr(174), Tyr(183) and Tyr(446) in mouse 3BP2 are predominantly phosphorylated by Syk, and the phosphorylation of Tyr(183) and the Src homology 2 (SH2) domain of mouse 3BP2 are critical for B cell receptor (BCR)-induced activation of nuclear factor of activated T cells (NFAT) in human B cells. In this report, we have shown that Syk, but not Abl family protein-tyrosine kinases, is critical for BCR-mediated tyrosine phosphorylation of 3BP2 in chicken DT40 cells. Mutational analysis showed that Tyr(174), Tyr(183) and Tyr(426) of chicken 3BP2 are the major phosphorylation sites by Syk and the SH2 domain of 3BP2 is critical for tyrosine phosphorylation. In addition, phosphorylation of Tyr(426) is required for the inducible interaction with the SH2 domain of Vav3. Moreover, the expression of the mutant form of 3BP2 in which Tyr(426) was substituted to Phe resulted in the reduction in BCR-mediated Rac1 activation, when compared with the case of wild-type. Altogether, these data suggest that 3BP2 is involved in the activation of Rac1 through the regulation of Vav3 by Syk-dependent phosphorylation of Tyr(426) following BCR stimulation. Copyright © 2014 Elsevier Inc. All rights reserved.

Evidence-based guidelines for the use of tyrosine kinase inhibitors in adults with Philadelphia chromosome–positive or BCR-ABL–positive acute lymphoblastic leukemia: a Canadian consensus

PubMed Central

Couban, S.; Savoie, L.; Mourad, Y. Abou; Leber, B.; Minden, M.; Turner, R.; Palada, V.; Shehata, N.; Christofides, A.; Lachance, S.

2014-01-01

Adult Philadelphia chromosome–positive (Ph+) or BCR-ABL–positive (BCR-ABL+) acute lymphoblastic leukemia (all) is an acute leukemia previously associated with a high relapse rate, short disease-free survival, and poor overall survival. In adults, allogeneic hematopoietic cell transplant in first remission remains the only proven curative strategy for transplant-eligible patients. The introduction of tyrosine kinase inhibitors (tkis) in the treatment of patients with Ph+ or BCR-ABL+ all has significantly improved the depth and duration of complete remission, allowing more patients to proceed to transplantation. Although tkis are now considered a standard of care in this setting, few randomized trials have examined the optimal use of tkis in patients with Ph+ all. Questions of major importance remain, including the best way to administer these medications, the choice of tki to administer, and the schedule and the duration to use. We present the results of a systematic review of the literature with consensus recommendations based on the available evidence. PMID:24764712

Fungal Morphogenetic Pathways Are Required for the Hallmark Inflammatory Response during Candida albicans Vaginitis

PubMed Central

Palmer, Glen E.; Nash, Andrea K.; Lilly, Elizabeth A.; Fidel, Paul L.; Noverr, Mairi C.

2014-01-01

Vulvovaginal candidiasis, caused primarily by Candida albicans, presents significant health issues for women of childbearing age. As a polymorphic fungus, the ability of C. albicans to switch between yeast and hyphal morphologies is considered its central virulence attribute. Armed with new criteria for defining vaginitis immunopathology, the purpose of this study was to determine whether the yeast-to-hypha transition is required for the hallmark inflammatory responses previously characterized during murine vaginitis. Kinetic analyses of vaginal infection with C. albicans in C57BL/6 mice demonstrated that fungal burdens remained constant throughout the observation period, while polymorphonuclear leukocyte (PMN), S100A8, and interleukin-1β levels obtained from vaginal lavage fluid increased by day 3 onward. Lactate dehydrogenase activity was also positively correlated with increased effectors of innate immunity. Additionally, immunodepletion of neutrophils in infected mice confirmed a nonprotective role for PMNs during vaginitis. Determination of the importance of fungal morphogenesis during vaginitis was addressed with a two-pronged approach. Intravaginal inoculation of mice with C. albicans strains deleted for key transcriptional regulators (bcr1Δ/Δ, efg1Δ/Δ, cph1Δ/Δ, and efg1Δ/Δ cph1Δ/Δ) controlling the yeast-to-hypha switch revealed a crucial role for morphogenetic signaling through the Efg1 and, to a lesser extent, the Bcr1 pathways in contributing to vaginitis immunopathology. Furthermore, overexpression of transcription factors NRG1 and UME6, to maintain yeast and hyphal morphologies, respectively, confirmed the importance of morphogenesis in generating innate immune responses in vivo. These results highlight the yeast-to-hypha switch and the associated morphogenetic response as important virulence components for the immunopathogenesis of Candida vaginitis, with implications for transition from benign colonization to symptomatic infection. PMID:24478069

Diagnosis and classification of hematologic malignancies on the basis of genetics

PubMed Central

2017-01-01

Genomic analysis has greatly influenced the diagnosis and clinical management of patients affected by diverse forms of hematologic malignancies. Here, we review how genetic alterations define subclasses of patients with acute leukemias, myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPNs), non-Hodgkin lymphomas, and classical Hodgkin lymphoma. These include new subtypes of acute myeloid leukemia defined by mutations in RUNX1 or BCR-ABL1 translocations as well as a constellation of somatic structural DNA alterations in acute lymphoblastic leukemia. Among patients with MDS, detection of mutations in SF3B1 define a subgroup of patients with the ring sideroblast form of MDS and a favorable prognosis. For patients with MPNs, detection of the BCR-ABL1 fusion delineates chronic myeloid leukemia from classic BCR-ABL1− MPNs, which are largely defined by mutations in JAK2, CALR, or MPL. In the B-cell lymphomas, detection of characteristic rearrangements involving MYC in Burkitt lymphoma, BCL2 in follicular lymphoma, and MYC/BCL2/BCL6 in high-grade B-cell lymphomas are essential for diagnosis. In T-cell lymphomas, anaplastic large-cell lymphoma is defined by mutually exclusive rearrangements of ALK, DUSP22/IRF4, and TP63. Genetic alterations affecting TP53 and the mutational status of the immunoglobulin heavy-chain variable region are important in clinical management of chronic lymphocytic leukemia. Additionally, detection of BRAFV600E mutations is helpful in the diagnosis of classical hairy cell leukemia and a number of histiocytic neoplasms. Numerous additional examples provided here demonstrate how clinical evaluation of genomic alterations have refined classification of myeloid neoplasms and major forms of lymphomas arising from B, T, or natural killer cells. PMID:28600336

Rare cancer cell analyzer for whole blood applications: automated nucleic acid purification in a microfluidic disposable card.

PubMed

Kokoris, M; Nabavi, M; Lancaster, C; Clemmens, J; Maloney, P; Capadanno, J; Gerdes, J; Battrell, C F

2005-09-01

One current challenge facing point-of-care cancer detection is that existing methods make it difficult, time consuming and too costly to (1) collect relevant cell types directly from a patient sample, such as blood and (2) rapidly assay those cell types to determine the presence or absence of a particular type of cancer. We present a proof of principle method for an integrated, sample-to-result, point-of-care detection device that employs microfluidics technology, accepted assays, and a silica membrane for total RNA purification on a disposable, credit card sized laboratory-on-card ('lab card") device in which results are obtained in minutes. Both yield and quality of on-card purified total RNA, as determined by both LightCycler and standard reverse transcriptase amplification of G6PDH and BCR-ABL transcripts, were found to be better than or equal to accepted standard purification methods.

The roles of microRNAs in the pathogenesis and drug resistance of chronic myelogenous leukemia (Review).

PubMed

Di Stefano, Carla; Mirone, Giovanna; Perna, Stefania; Marfe, Gabriella

2016-02-01

Chronic myeloid leukemia (CML) is characterized by the accumulation of Philadelphia chromosome-positive (Ph+) myeloid cells. Ph+ cells occur via a reciprocal translocation between the long arms of chromosomes 9 and 22 resulting in constitutively active BCR-ABL fusion protein. Tyrosine kinase inhibitors (TKIs) are used against the kinase activity of BCR-ABL protein for the effective treatment of CML. However, the development of drug resistance, caused by different genetic mechanisms, is the major issue in the clinical application of TKIs. These mechanisms include changes in expression levels of microRNAs (miRNAs). miRNAs are short non-coding regulatory RNAs that control gene expression and play an important role in cancer development and progression. In the present review, we highlight the roles of miRNAs both in the progression and chemotherapy-resistance of CML. Our understanding of these mechanisms may lead to the use of this knowledge not only in the treatment of patients with CML, but also in other type of cancers.

Intracellular Retention of ABL Kinase Inhibitors Determines Commitment to Apoptosis in CML Cells

PubMed Central

Dziadosz, Marek; Schnöder, Tina; Heidel, Florian; Schemionek, Mirle; Melo, Junia V.; Kindler, Thomas; Müller-Tidow, Carsten; Koschmieder, Steffen; Fischer, Thomas

2012-01-01

Clinical development of imatinib in CML established continuous target inhibition as a paradigm for successful tyrosine kinase inhibitor (TKI) therapy. However, recent reports suggested that transient potent target inhibition of BCR-ABL by high-dose TKI (HD-TKI) pulse-exposure is sufficient to irreversibly commit cells to apoptosis. Here, we report a novel mechanism of prolonged intracellular TKI activity upon HD-TKI pulse-exposure (imatinib, dasatinib) in BCR-ABL-positive cells. Comprehensive mechanistic exploration revealed dramatic intracellular accumulation of TKIs which closely correlated with induction of apoptosis. Cells were rescued from apoptosis upon HD-TKI pulse either by repetitive drug wash-out or by overexpression of ABC-family drug transporters. Inhibition of ABCB1 restored sensitivity to HD-TKI pulse-exposure. Thus, our data provide evidence that intracellular drug retention crucially determines biological activity of imatinib and dasatinib. These studies may refine our current thinking on critical requirements of TKI dose and duration of target inhibition for biological activity of TKIs. PMID:22815843

Heterogeneity of leukemia-initiating capacity of chronic myelogenous leukemia stem cells

PubMed Central

Zhang, Bin; Li, Ling; Ho, Yinwei; Li, Min; Marcucci, Guido

2016-01-01

Chronic myelogenous leukemia (CML) results from transformation of a long-term hematopoietic stem cell (LTHSC) by expression of the BCR-ABL fusion gene. However, BCR-ABL–expressing LTHSCs are heterogeneous in their capacity as leukemic stem cells (LSCs). Although discrepancies in proliferative, self-renewal, and differentiation properties of normal LTHSCs are being increasingly recognized, the mechanisms underlying heterogeneity of leukemic LTHSCs are poorly understood. Using a CML mouse model, we identified gene expression differences between leukemic and nonleukemic LTHSCs. Expression of the thrombopoietin (THPO) receptor MPL was elevated in leukemic LTHSC populations. Compared with LTHSCs with low MPL expression, LTHSCs with high MPL expression showed enhanced JAK/STAT signaling and proliferation in response to THPO in vitro and increased leukemogenic capacity in vivo. Although both G0 and S phase subpopulations were increased in LTHSCs with high MPL expression, LSC capacity was restricted to quiescent cells. Inhibition of MPL expression in CML LTHSCs reduced THPO-induced JAK/STAT signaling and leukemogenic potential. These same phenotypes were also present in LTHSCs from patients with CML, and patient LTHSCs with high MPL expression had reduced sensitivity to BCR-ABL tyrosine kinase inhibitor treatment but increased sensitivity to JAK inhibitors. Together, our studies identify MPL expression levels as a key determinant of heterogeneous leukemia-initiating capacity and drug sensitivity of CML LTHSCs and suggest that high MPL–expressing CML stem cells are potential targets for therapy. PMID:26878174

Overexpression of miR-202 resensitizes imatinib resistant chronic myeloid leukemia cells through targetting Hexokinase 2

PubMed Central

Deng, Yingjun; Li, Xin; Feng, Jinxin; Zhang, Xiangliang

2018-01-01

Chronic myeloid leukemia (CML) is a myeloproliferative disease which uniquely expresses a constitutively active tyrosine kinase, BCR/ABL. As a specific inhibitor of the BCR-ABL tyrosine kinase, imatinib becomes the first choice for the treatment of CML due to its high efficacy and low toxicity. However, the development of imatinib resistance limits the long-term treatment benefits of it in CML patients. In the present study, we aimed to investigate the roles of miR-202 in the regulation of imatinib sensitivity in CML cell lines and the possible mechanisms involved in this process. We found miR-202 was down-regulated in seven CML cell lines by quantitative reverse-transcription PCR (qRT-PCR) analysis. Overexpression of miR-202 significantly suppressed proliferation rates of CML cells. By establishing imatinib resistant cell lines originating from K562 and KU812 cells, we observed expressions of miR-202 were down-regulated by imatinib treatments and imatinib resistant CML cell lines exhibited lower level of miR-202. On the contrary, imatinib resistant CML cell lines displayed up-regulated glycolysis rate than sensitive cells with the evidence that glucose uptake, lactate production, and key glycolysis enzymes were elevated in imatinib resistant cells. Importantly, the imatinib resistant CML cell lines were more sensitive to glucose starvation and glycolysis inhibitors. In addition, we identified Hexokinase 2 (HK2) as a direct target of miR-202 in CML cell lines. Overexpression of miR-202 sensitized imatinib resistant CML through the miR-202-mediated glycolysis inhibition by targetting HK2. Finally, we provided the clinical relevance that miR-202 was down-regulated in CML patients and patients with lower miR-202 expression displayed higher HK2 expression. The present study will provide new aspects on the miRNA-modulated tyrosine kinase inhibitor (TKI) sensitivity in CML, contributing to the development of new therapeutic anticancer drugs. PMID:29559564

Structure guided design of potent and selective ponatinib-based hybrid inhibitors for RIPK1

PubMed Central

Najjar, Malek; Suebsuwong, Chalada; Ray, Soumya S.; Thapa, Roshan J.; Maki, Jenny L.; Nogusa, Shoko; Shah, Saumil; Saleh, Danish; Gough, Peter J.; Bertin, John; Yuan, Junying; Balachandran, Siddharth; Cuny, Gregory D.; Degterev, Alexei

2015-01-01

Summary RIPK1 and RIPK3, two closely related RIPK family members, have emerged as important regulators of pathologic cell death and inflammation. In the current work, we report that the Bcr-Abl inhibitor and anti-leukemia agent ponatinib is also a first-in-class dual inhibitor of RIPK1 and RIPK3. Ponatinib potently inhibited multiple paradigms of RIPK1- and RIPK3-dependent cell death and inflammatory TNFα gene transcription. We further describe design strategies that utilize the ponatinib scaffold to develop two classes of inhibitors (CS and PN series), each with greatly improved selectivity for RIPK1. In particular, we detail the development of PN10, a highly potent and selective ‘hybrid’ RIPK1 inhibitor, capturing the best properties of two different allosteric RIPK1 inhibitors, ponatinib and necrostatin-1. Finally, we show that RIPK1 inhibitors from both classes are powerful blockers of TNF-induced injury in vivo. Altogether, these findings outline promising candidate molecules and design approaches for targeting RIPK1/3-driven inflammatory pathologies. PMID:25801024

Tonic B-cell receptor signaling in diffuse large B-cell lymphoma.

PubMed

Havranek, Ondrej; Xu, Jingda; Köhrer, Stefan; Wang, Zhiqiang; Becker, Lisa; Comer, Justin M; Henderson, Jared; Ma, Wencai; Man Chun Ma, John; Westin, Jason R; Ghosh, Dipanjan; Shinners, Nicholas; Sun, Luhong; Yi, Allen F; Karri, Anusha R; Burger, Jan A; Zal, Tomasz; Davis, R Eric

2017-08-24

We used clustered regularly interspaced short palindromic repeats/Cas9-mediated genomic modification to investigate B-cell receptor (BCR) signaling in cell lines of diffuse large B-cell lymphoma (DLBCL). Three manipulations that altered BCR genes without affecting surface BCR levels showed that BCR signaling differs between the germinal center B-cell (GCB) subtype, which is insensitive to Bruton tyrosine kinase inhibition by ibrutinib, and the activated B-cell (ABC) subtype. Replacing antigen-binding BCR regions had no effect on BCR signaling in GCB-DLBCL lines, reflecting this subtype's exclusive use of tonic BCR signaling. Conversely, Y188F mutation in the immunoreceptor tyrosine-based activation motif of CD79A inhibited tonic BCR signaling in GCB-DLBCL lines but did not affect their calcium flux after BCR cross-linking or the proliferation of otherwise-unmodified ABC-DLBCL lines. CD79A-GFP fusion showed BCR clustering or diffuse distribution, respectively, in lines of ABC and GCB subtypes. Tonic BCR signaling acts principally to activate AKT, and forced activation of AKT rescued GCB-DLBCL lines from knockout (KO) of the BCR or 2 mediators of tonic BCR signaling, SYK and CD19. The magnitude and importance of tonic BCR signaling to proliferation and size of GCB-DLBCL lines, shown by the effect of BCR KO, was highly variable; in contrast, pan-AKT KO was uniformly toxic. This discrepancy was explained by finding that BCR KO-induced changes in AKT activity (measured by gene expression, CXCR4 level, and a fluorescent reporter) correlated with changes in proliferation and with baseline BCR surface density. PTEN protein expression and BCR surface density may influence clinical response to therapeutic inhibition of tonic BCR signaling in DLBCL. © 2017 by The American Society of Hematology.

In vitro testing of drug combinations employing nilotinib and alkylating agents with regard to pretransplant conditioning treatment of advanced-phase chronic myeloid leukemia.

PubMed

Radujkovic, Aleksandar; Luft, Thomas; Dreger, Peter; Ho, Anthony D; Jens Zeller, W; Fruehauf, Stefan; Topaly, Julian

2014-08-01

The prognosis of patients with advanced-phase chronic myeloid leukemia (CML) remains dismal despite the availability of targeted therapies and allogeneic stem cell transplantation (allo-SCT). Increasing the antileukemic efficacy of the pretransplant conditioning regimen may be a strategy to increase remission rates and duration. We therefore investigated the antiproliferative effects of nilotinib in combination with drugs that are usually used for conditioning: the alkylating agents mafosfamide, treosulfan, and busulfan. Drug combinations were tested in vitro in different imatinib-sensitive and imatinib-resistant BCR-ABL-positive cell lines. A tetrazolium-based MTT assay was used for the assessment and quantification of growth inhibition after exposure to alkylating agents alone or to combinations with nilotinib. Drug interaction was analyzed using the median-effect method of Chou and Talalay, and combination index (CI) values were calculated according to the classic isobologram equation. Treatment of imatinib-sensitive, BCR-ABL-positive K562 and LAMA84 cells with nilotinib in combination with mafosfamide, treosulfan, or busulfan resulted in synergistic (CI < 1), additive (CI ~ 1), and predominantly antagonistic (CI > 1) effects, respectively. In imatinib-resistant K562-R and LAMA84-R cells, all applied drug combinations were synergistic (CI < 1) at higher growth inhibition levels. Our in vitro data warrant further investigation and may provide the basis for nilotinib-supplemented conditioning regimens for allo-SCT in advanced-phase CML.

Heterogeneity of chromosome 22 breakpoint in Philadelphia-positive (Ph/sup +/) acute lymphocytic leukemia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erikson, J.; Griffin, C.A.; Ar-Rushdi, A.

1986-03-01

In chronic myelogenous leukemias (CML) with the t(9;22)(q34;q11) chromosome translocation the breakpoints on chromosome 22 occur within a 5.8-kilobase segment of DNA referred to as breakpoint cluster region (bcr). The same cytogenetically indinstinguishable translocation occurs in approximately 10% of patients with acute lymphocytic leukemias (ALL). In this study the authors have investigated the chromosome breakpoints in several cases of ALL carrying the t(9;22) translocation. In three of five cases of ALL they found that the bcr region was not involved in the chromosome rearrangement and that the 22q11 chromosome breakpoints were proximal (5') to the bcr region at band 22q11.more » In addition, they observed normal size bcr and c-alb transcripts in an ALL cell line carrying the t(9;22) translocation. They conclude, therefore, that if c-alb is inappropriately expressed in ALL cells without bcr rearrangements, the genetic mechanism of activation must be different from that reported for CML.« less

Gene expression in Listeria monocytogenes exposed to sublethal concentration of benzalkonium chloride.

PubMed

Tamburro, Manuela; Ripabelli, Giancarlo; Vitullo, Monia; Dallman, Timothy James; Pontello, Mirella; Amar, Corinne Francoise Laurence; Sammarco, Michela Lucia

2015-06-01

In this study, tolerance at sublethal concentration of benzalkonium chloride and transcription levels of mdrL, ladR, lde, sigB and bcrABC genes in Listeria monocytogenes strains were evaluated. Viable cells reduction occurred in 45% of strains and clinical isolates showed lower sensitivity than isolates from foods. An increased transcription of an efflux system encoding gene was found in 60% of strains, and simultaneous mdrL overexpression and ladR underexpression occurred in 30% of isolates. A significant association between reduced benzalkonium chloride activity and both mdrL and sigB overexpression was observed; sigB expression also correlated with both mdrL and ladR genes. The bcrABC gene was only found in six strains, all isolated from foods and sensitive to benzalkonium chloride, and in four strains an underexpression was observed. Disinfection at sublethal concentration was less effective in clinical isolates, and mdrL and sigB expression was significantly affected by disinfection. Further insights are needed to understand the adaptation to benzalkonium chloride and to evaluate whether changes in gene expression could affect the L. monocytogenes virulence traits and persistence in the environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pentostatin and Lymphocyte Infusion in Preventing Graft Rejection in Patients Who Have Undergone Donor Stem Cell Transplant

ClinicalTrials.gov

2018-05-24

Acute Lymphoblastic Leukemia; Acute Myeloid Leukemia; Chronic Lymphocytic Leukemia; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Graft Versus Host Disease; Hodgkin Lymphoma; Myelodysplastic/Myeloproliferative Neoplasm; Non-Hodgkin Lymphoma; Plasma Cell Myeloma; Waldenstrom Macroglobulinemia

Evaluation of cooperative antileukemic effects of nilotinib and vildagliptin in Ph+ chronic myeloid leukemia.

PubMed

Willmann, Michael; Sadovnik, Irina; Eisenwort, Gregor; Entner, Martin; Bernthaler, Tina; Stefanzl, Gabriele; Hadzijusufovic, Emir; Berger, Daniela; Herrmann, Harald; Hoermann, Gregor; Valent, Peter; Rülicke, Thomas

2018-01-01

Chronic myeloid leukemia (CML) is a stem cell (SC) neoplasm characterized by the BCR/ABL1 oncogene. Although the disease can be kept under control using BCR/ABL1 tyrosine kinase inhibitors (TKIs) in most cases, some patients relapse or have resistant disease, so there is a need to identify new therapeutic targets in this malignancy. Recent data suggest that leukemic SCs (LSCs) in CML display the stem-cell (SC)-mobilizing cell surface enzyme dipeptidyl-peptidase IV (DPPIV = CD26) in an aberrant manner. In the present study, we analyzed the effects of the DPPIV blocker vildagliptin as single agent or in combination with the BCR/ABL1 TKI imatinib or nilotinib on growth and survival of CML LSCs in vitro and on LSC engraftment in an in vivo xenotransplantation nonobese diabetic SCID-IL-2Rγ -/- (NSG) mouse model. We found that nilotinib induces apoptosis in CML LSCs and inhibits their engraftment in NSG mice. In contrast, no substantial effects were seen with imatinib or vildagliptin. Nevertheless, vildagliptin was found to reduce the "mobilization" of CML LSCs from a stroma cell layer consisting of mouse fibroblasts in an in vitro co-culture model, suggesting reduced disease expansion. However, although vildagliptin and nilotinib produced cooperative effects in individual experiments, overall, no significant effects of coadministered vildagliptin over nilotinib or imatinib treatment alone were seen on the engraftment of CML cells in NSG mice. Gliptins may be interesting drugs in the context of CML and nilotinib therapy, but our preclinical studies did not reveal a major cooperative effect of the drug-combination vildagliptin + nilotinib on engraftment of CML cells in NSG mice. Copyright © 2018 ISEH – Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

European LeukemiaNet recommendations for the management of chronic myeloid leukemia: 2013

PubMed Central

Deininger, Michael W.; Rosti, Gianantonio; Hochhaus, Andreas; Soverini, Simona; Apperley, Jane F.; Cervantes, Francisco; Clark, Richard E.; Cortes, Jorge E.; Guilhot, François; Hjorth-Hansen, Henrik; Hughes, Timothy P.; Kantarjian, Hagop M.; Kim, Dong-Wook; Larson, Richard A.; Lipton, Jeffrey H.; Mahon, François-Xavier; Martinelli, Giovanni; Mayer, Jiri; Müller, Martin C.; Niederwieser, Dietger; Pane, Fabrizio; Radich, Jerald P.; Rousselot, Philippe; Saglio, Giuseppe; Saußele, Susanne; Schiffer, Charles; Silver, Richard; Simonsson, Bengt; Steegmann, Juan-Luis; Goldman, John M.; Hehlmann, Rüdiger

2013-01-01

Advances in chronic myeloid leukemia treatment, particularly regarding tyrosine kinase inhibitors, mandate regular updating of concepts and management. A European LeukemiaNet expert panel reviewed prior and new studies to update recommendations made in 2009. We recommend as initial treatment imatinib, nilotinib, or dasatinib. Response is assessed with standardized real quantitative polymerase chain reaction and/or cytogenetics at 3, 6, and 12 months. BCR-ABL1 transcript levels ≤10% at 3 months, <1% at 6 months, and ≤0.1% from 12 months onward define optimal response, whereas >10% at 6 months and >1% from 12 months onward define failure, mandating a change in treatment. Similarly, partial cytogenetic response (PCyR) at 3 months and complete cytogenetic response (CCyR) from 6 months onward define optimal response, whereas no CyR (Philadelphia chromosome–positive [Ph+] >95%) at 3 months, less than PCyR at 6 months, and less than CCyR from 12 months onward define failure. Between optimal and failure, there is an intermediate warning zone requiring more frequent monitoring. Similar definitions are provided for response to second-line therapy. Specific recommendations are made for patients in the accelerated and blastic phases, and for allogeneic stem cell transplantation. Optimal responders should continue therapy indefinitely, with careful surveillance, or they can be enrolled in controlled studies of treatment discontinuation once a deeper molecular response is achieved. PMID:23803709

Switching to second-generation tyrosine kinase inhibitor improves the response and outcome of frontline imatinib-treated patients with chronic myeloid leukemia with more than 10% of BCR-ABL/ABL ratio at 3 months

PubMed Central

Casado, Luis-Felipe; García-Gutiérrez, José-Valentín; Massagué, Isabel; Giraldo, Pilar; Pérez-Encinas, Manuel; de Paz, Raquel; Martínez-López, Joaquín; Bautista, Guiomar; Osorio, Santiago; Requena, María-José; Palomera, Luis; Peñarrubia, María-Jesús; Calle, Carmen; Hernández-Rivas, José-Ángel; Burgaleta, Carmen; Maestro, Begoña; García-Ormeña, Nuria; Steegmann, Juan-Luis

2015-01-01

Chronic myeloid leukemia patients display heterogeneous responses to imatinib. Survival depends on baseline clinical characteristics (including prognostic scoring systems) and on early response (such as >10% BCR-ABL/ABL ratio at 3 months of therapy). The results of switching to second-generation tyrosine kinase inhibitors (2GTKIs) may contain a bias since, in the majority of these studies, patients who switch treatment due to intolerance or failure are censored or excluded. We analyzed the Spanish Registry data on switching in an intention-to-treat analysis of patients in standard clinical practice. Switching to 2GTKIs improves responses from 45% to 75% of complete cytogenetic response (CCyR) and from 15% to 45% of major molecular response (MMR) in the group without molecular response 1 (MR1) at 3 months and from 70% to 87% in CCyR and from 52% to 87% in MMR in the group with MR1. The final response rate is poorer in the group with no MR1 at 3 months. Nevertheless, the differences in the rates of response were not translated into differences in major events (transformations or deaths), and the final progression-free survival and overall survival were similar. PMID:25756742

CM363, a novel naphthoquinone derivative which acts as multikinase modulator and overcomes imatinib resistance in chronic myelogenous leukemia

PubMed Central

Díaz-Chico, Juan Carlos; McNaughton-Smith, Grant; Jiménez-Alonso, Sandra; Hueso-Falcón, Idaira; Montero, Juan Carlos; Blanco, Raquel; León, Javier; Rodríguez-González, Germán; Estévez-Braun, Ana; Pandiella, Atanasio; Díaz-Chico, Bonifacio Nicolás; Fernández-Pérez, Leandro

2017-01-01

Human Chronic Myelogenous Leukemia (CML) is a hematological stem cell disorder which is associated with activation of Bcr-Abl-Stat5 oncogenic pathway. Direct Bcr-Abl inhibitors are initially successful for the treatment of CML but over time many patients develop drug resistance. In the present study, the effects of CM363, a novel naphthoquinone (NPQ) derivative, were evaluated on human CML-derived K562 cells. CM363 revealed an effective cell growth inhibition (IC50 = 0.7 ± 0.5 μM) by inducing cancer cells to undergo cell cycle arrest and apoptosis. CM363 caused a dose- and time-dependent reduction of cells in G0/G1 and G2/M phases. This cell cycle arrest was associated with increased levels of cyclin E, pChk1 and pChk2 whereas CM363 downregulated cyclin B, cyclin D3, p27, pRB, Wee1, and BUBR1. CM363 increased the double-strand DNA break marker γH2AX. CM363 caused a time-dependent increase of annexin V-positive cells, DNA fragmentation and increased number of apoptotic nuclei. CM363 triggered the mitochondrial apoptotic pathway as reflected by a release of cytochrome C from mitochondria and induction of the cleavage of caspase-3 and -9, and PARP. CM363 showed multikinase modulatory effects through an early increased JNK phosphorylation followed by inhibition of pY-Bcrl-Abl and pY-Stat5. CM363 worked synergistically with imatinib to inhibit cell viability and maintained its activity in imatinib-resistant cells. Finally, CM363 (10 mg/Kg) suppressed the growth of K562 xenograft tumors in athymic mice. In summary, CM363 is a novel multikinase modulator that offers advantages to circumvent imanitib resistance and might be therapeutically effective in Bcrl-Abl-Stat5 related malignancies. PMID:27557509

CM363, a novel naphthoquinone derivative which acts as multikinase modulator and overcomes imatinib resistance in chronic myelogenous leukemia.

PubMed

Guerra, Borja; Martín-Rodríguez, Patricia; Díaz-Chico, Juan Carlos; McNaughton-Smith, Grant; Jiménez-Alonso, Sandra; Hueso-Falcón, Idaira; Montero, Juan Carlos; Blanco, Raquel; León, Javier; Rodríguez-González, Germán; Estévez-Braun, Ana; Pandiella, Atanasio; Díaz-Chico, Bonifacio Nicolás; Fernández-Pérez, Leandro

2017-05-02

Human Chronic Myelogenous Leukemia (CML) is a hematological stem cell disorder which is associated with activation of Bcr-Abl-Stat5 oncogenic pathway. Direct Bcr-Abl inhibitors are initially successful for the treatment of CML but over time many patients develop drug resistance. In the present study, the effects of CM363, a novel naphthoquinone (NPQ) derivative, were evaluated on human CML-derived K562 cells. CM363 revealed an effective cell growth inhibition (IC50 = 0.7 ± 0.5 μM) by inducing cancer cells to undergo cell cycle arrest and apoptosis. CM363 caused a dose- and time-dependent reduction of cells in G0/G1 and G2/M phases. This cell cycle arrest was associated with increased levels of cyclin E, pChk1 and pChk2 whereas CM363 downregulated cyclin B, cyclin D3, p27, pRB, Wee1, and BUBR1. CM363 increased the double-strand DNA break marker γH2AX. CM363 caused a time-dependent increase of annexin V-positive cells, DNA fragmentation and increased number of apoptotic nuclei. CM363 triggered the mitochondrial apoptotic pathway as reflected by a release of cytochrome C from mitochondria and induction of the cleavage of caspase-3 and -9, and PARP. CM363 showed multikinase modulatory effects through an early increased JNK phosphorylation followed by inhibition of pY-Bcrl-Abl and pY-Stat5. CM363 worked synergistically with imatinib to inhibit cell viability and maintained its activity in imatinib-resistant cells. Finally, CM363 (10 mg/Kg) suppressed the growth of K562 xenograft tumors in athymic mice. In summary, CM363 is a novel multikinase modulator that offers advantages to circumvent imanitib resistance and might be therapeutically effective in Bcrl-Abl-Stat5 related malignancies.

Nilotinib and Combination Chemotherapy in Treating Patients With Newly Diagnosed Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia or Blastic Phase Chronic Myelogenous Leukemia

ClinicalTrials.gov

2015-10-29

B-cell Adult Acute Lymphoblastic Leukemia; Blastic Phase Chronic Myelogenous Leukemia; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Philadelphia Chromosome Positive Adult Precursor Acute Lymphoblastic Leukemia; Untreated Adult Acute Lymphoblastic Leukemia

Tacrolimus, Bortezomib, & Thymoglobulin in Preventing Low Toxicity GVHD in Donor Blood Stem Cell Transplant Patients

ClinicalTrials.gov

2018-03-30

Acute Leukemia; Chronic Lymphocytic Leukemia; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Diffuse Large B-Cell Lymphoma; Follicular Lymphoma; Graft Versus Host Disease; Mantle Cell Lymphoma; Marginal Zone Lymphoma; Myelodysplastic Syndrome; Myelofibrosis; Myeloproliferative Neoplasm; Small Lymphocytic Lymphoma

Exploiting temporal collateral sensitivity in tumor clonal evolution

PubMed Central

Zhao, Boyang; Sedlak, Joseph C.; Srinivas, Raja; Creixell, Pau; Pritchard, Justin R.; Tidor, Bruce; Lauffenburger, Douglas A.; Hemann, Michael T.

2016-01-01

SUMMARY The prevailing approach to addressing secondary drug resistance in cancer focuses on treating the resistance mechanisms at relapse. However, the dynamic nature of clonal evolution, along with potential fitness costs and cost compensations, may present exploitable vulnerabilities; a notion that we term ‘temporal collateral sensitivity’. Using a combined pharmacological screen and drug resistance selection approach in a murine model of Ph+ acute lymphoblastic leukemia, we indeed find that temporal and/or persistent collateral sensitivity to non-classical BCR-ABL1 drugs arises in emergent tumor subpopulations during the evolution of resistance toward initial treatment with BCR-ABL1 targeted inhibitors. We determined the sensitization mechanism via genotypic, phenotypic, signaling, and binding measurements in combination with computational models, and demonstrated significant overall survival extension in mice. Additional stochastic mathematical models and small molecule screens extended our insights, indicating the value of focusing on evolutionary trajectories and pharmacological profiles to identify new strategies to treat dynamic tumor vulnerabilities. PMID:26924578

Exploiting Temporal Collateral Sensitivity in Tumor Clonal Evolution.

PubMed

Zhao, Boyang; Sedlak, Joseph C; Srinivas, Raja; Creixell, Pau; Pritchard, Justin R; Tidor, Bruce; Lauffenburger, Douglas A; Hemann, Michael T

2016-03-24

The prevailing approach to addressing secondary drug resistance in cancer focuses on treating the resistance mechanisms at relapse. However, the dynamic nature of clonal evolution, along with potential fitness costs and cost compensations, may present exploitable vulnerabilities-a notion that we term "temporal collateral sensitivity." Using a combined pharmacological screen and drug resistance selection approach in a murine model of Ph(+) acute lymphoblastic leukemia, we indeed find that temporal and/or persistent collateral sensitivity to non-classical BCR-ABL1 drugs arises in emergent tumor subpopulations during the evolution of resistance toward initial treatment with BCR-ABL1-targeted inhibitors. We determined the sensitization mechanism via genotypic, phenotypic, signaling, and binding measurements in combination with computational models and demonstrated significant overall survival extension in mice. Additional stochastic mathematical models and small-molecule screens extended our insights, indicating the value of focusing on evolutionary trajectories and pharmacological profiles to identify new strategies to treat dynamic tumor vulnerabilities. Copyright © 2016 Elsevier Inc. All rights reserved.

The co-occurrence of driver mutations in chronic myeloproliferative neoplasms.

PubMed

Boddu, Prajwal; Chihara, Dai; Masarova, Lucia; Pemmaraju, Naveen; Patel, Keyur P; Verstovsek, Srdan

2018-06-27

Myeloproliferative neoplasms (MPNs) are clonal disorders characterized by proliferation of one or more elements of the myeloid lineage. Key genetic aberrations include the BCR-ABL1 gene rearrangement in Philadelphia chromosome-positive chronic myelogenous leukemia (CML) and JAK2/MPL/CALR aberrations in Philadelphia chromosome-negative MPNs. While thought to be mutually exclusive, occasional isolated reports of coexistence of BCR-ABL1 and JAK2, and JAK2 with MPL or CALR aberrations have been described. Given the paucity of data, clinical characteristics and outcome of patients harboring concurrent Philadelphia-positive and Philadelphia-negative mutations or dual Philadelphia-negative driver mutations have not been systematically evaluated, and their clinical relevance is largely unknown. It is difficult to determine the true relevance of co-existing driver mutations on outcomes given the rarity of its occurrence. In this case series, we describe those patients who had dual driver mutations detected at any point during the course of their disease and characterized their clinical and laboratory features, bone marrow pathology, and overall disease course.

Src-like adaptor protein (SLAP) regulates B cell receptor levels in a c-Cbl-dependent manner.

PubMed

Dragone, Leonard L; Myers, Margaret D; White, Carmen; Gadwal, Shyam; Sosinowski, Tomasz; Gu, Hua; Weiss, Arthur

2006-11-28

Src-like adaptor protein (SLAP) and c-Cbl recently have been shown to cooperate in regulating T cell receptor (TCR) levels in developing T cells. SLAP also is expressed in developing B cells, and its deficiency leads to alterations in B cell receptor (BCR) levels and B cell development. Hence, we hypothesized that SLAP and c-Cbl may cooperate during B cell development to regulate BCR levels. In mice deficient in both SLAP and c-Cbl, we found that B cell development is altered, suggesting that they function through intersecting pathways. To study the mechanism by which SLAP and c-Cbl alter BCR levels, we coexpressed them in a mature mouse B cell line (Bal-17). First we determined that SLAP associates with proximal components of the BCR complex after stimulation and internalization. Coexpression of SLAP and c-Cbl in Bal-17 led to decreased surface and total BCR levels. This decrease in BCR levels depended on intact Src homology 2 (SH2) and C-terminal domains of SLAP. In addition, a mutation in the SH2 domain of SLAP blocked its colocalization with c-Cbl and the BCR complex, whereas deletion of the C terminus did not affect its localization. Last, coexpression of SLAP and c-Cbl altered BCR complex recycling. This alteration in BCR complex recycling depended on enzymatically active c-Cbl and Src family kinases, as well as the intact SH2 and C-terminal domains of SLAP. These data suggest that SLAP has a conserved function in B and T cells by adapting c-Cbl to the antigen-receptor complex and targeting it for degradation.

Src-like adaptor protein (SLAP) regulates B cell receptor levels in a c-Cbl-dependent manner

PubMed Central

Dragone, Leonard L.; Myers, Margaret D.; White, Carmen; Gadwal, Shyam; Sosinowski, Tomasz; Gu, Hua; Weiss, Arthur

2006-01-01

Src-like adaptor protein (SLAP) and c-Cbl recently have been shown to cooperate in regulating T cell receptor (TCR) levels in developing T cells. SLAP also is expressed in developing B cells, and its deficiency leads to alterations in B cell receptor (BCR) levels and B cell development. Hence, we hypothesized that SLAP and c-Cbl may cooperate during B cell development to regulate BCR levels. In mice deficient in both SLAP and c-Cbl, we found that B cell development is altered, suggesting that they function through intersecting pathways. To study the mechanism by which SLAP and c-Cbl alter BCR levels, we coexpressed them in a mature mouse B cell line (Bal-17). First we determined that SLAP associates with proximal components of the BCR complex after stimulation and internalization. Coexpression of SLAP and c-Cbl in Bal-17 led to decreased surface and total BCR levels. This decrease in BCR levels depended on intact Src homology 2 (SH2) and C-terminal domains of SLAP. In addition, a mutation in the SH2 domain of SLAP blocked its colocalization with c-Cbl and the BCR complex, whereas deletion of the C terminus did not affect its localization. Last, coexpression of SLAP and c-Cbl altered BCR complex recycling. This alteration in BCR complex recycling depended on enzymatically active c-Cbl and Src family kinases, as well as the intact SH2 and C-terminal domains of SLAP. These data suggest that SLAP has a conserved function in B and T cells by adapting c-Cbl to the antigen-receptor complex and targeting it for degradation. PMID:17110436

Second generation tyrosine kinase inhibitors prevent disease progression in high-risk (high CIP2A) chronic myeloid leukaemia patients.

PubMed

Lucas, C M; Harris, R J; Holcroft, A K; Scott, L J; Carmell, N; McDonald, E; Polydoros, F; Clark, R E

2015-07-01

High cancerous inhibitor of PP2A (CIP2A) protein levels at diagnosis of chronic myeloid leukaemia (CML) are predictive of disease progression in imatinib-treated patients. It is not known whether this is true in patients treated with second generation tyrosine kinase inhibitors (2G TKI) from diagnosis, and whether 2G TKIs modulate the CIP2A pathway. Here, we show that patients with high diagnostic CIP2A levels who receive a 2G TKI do not progress, unlike those treated with imatinib (P=<0.0001). 2G TKIs induce more potent suppression of CIP2A and c-Myc than imatinib. The transcription factor E2F1 is elevated in high CIP2A patients and following 1 month of in vivo treatment 2G TKIs suppress E2F1 and reduce CIP2A; these effects are not seen with imatinib. Silencing of CIP2A, c-Myc or E2F1 in K562 cells or CML CD34+ cells reactivates PP2A leading to BCR-ABL suppression. CIP2A increases proliferation and this is only reduced by 2G TKIs. Patients with high CIP2A levels should be offered 2G TKI treatment in preference to imatinib. 2G TKIs disrupt the CIP2A/c-Myc/E2F1 positive feedback loop, leading to lower disease progression risk. The data supports the view that CIP2A inhibits PP2Ac, stabilising E2F1, creating a CIP2A/c-Myc/E2F1 positive feedback loop, which imatinib cannot overcome.

HOX gene expression in phenotypic and genotypic subgroups and low HOXA gene expression as an adverse prognostic factor in pediatric ALL.

PubMed

Starkova, Julia; Zamostna, Blanka; Mejstrikova, Ester; Krejci, Roman; Drabkin, Harry A; Trka, Jan

2010-12-01

HOX genes play an important role in both normal lymphopoiesis and leukemogenesis. However, HOX expression patterns in leukemia cells compared to normal lymphoid progenitors have not been systematically studied in acute lymphoblastic leukemia (ALL) subtypes. The RNA expression levels of HOXA, HOXB, and CDX1/2 genes were analyzed by qRT-PCR in a cohort of 61 diagnostic pediatric ALL samples and FACS-sorted subpopulations of normal lymphoid progenitors. The RNA expression of HOXA7-10, HOXA13, and HOXB2-4 genes was exclusively detected in leukemic cells and immature progenitors. The RNA expression of HOXB6 and CDX2 genes was exclusively detected in leukemic cells but not in B-lineage cells at any of the studied developmental stages. HOXA3-4, HOXA7, and HOXB3-4 genes were differentially expressed between BCP-ALL and T-ALL subgroups, and among genotypically defined MLL/AF4, TEL/AML1, BCR/ABL, hyperdiploid and normal karyotype subgroups. However, this differential expression did not define specific clusters in hierarchical cluster analysis. HOXA7 gene was low expressed at the RNA level in patients with hyperdiploid leukemia, whereas HOXB7 and CDX2 genes were low expressed in TEL/AML1-positive and BCR/ABL-positive cases, respectively. In contrast to previous findings in acute myeloid leukemia, high HOXA RNA expression was associated with an excellent prognosis in Cox's regression model (P = 0.03). In MLL/AF4-positive ALL, lower HOXA RNA expression correlated with the methylation status of their promoters. HOX gene RNA expression cannot discriminate leukemia subgroups or relative maturity of leukemic cells. However, HOXA RNA expression correlates with prognosis, and particular HOX genes are expressed in specific genotypically characterized subgroups.

Targeting survival pathways in chronic myeloid leukaemia stem cells

PubMed Central

Sinclair, A; Latif, A L; Holyoake, T L

2013-01-01

Chronic myeloid leukaemia (CML) is a clonal myeloproliferative disorder characterized by the presence of a fusion oncogene BCR-ABL, which encodes a protein with constitutive TK activity. The implementation of tyrosine kinase inhibitors (TKIs) marked a major advance in CML therapy; however, there are problems with current treatment. For example, relapse occurs when these drugs are discontinued in the majority of patients who have achieved a complete molecular response on TKI and these agents are less effective in patients with mutations in the BCR-ABL kinase domain. Importantly, TKI can effectively target proliferating mature cells, but do not eradicate quiescent leukaemic stem cells (LSCs), therefore allowing disease persistence despite treatment. It is essential that alternative strategies are used to target the LSC population. BCR-ABL activation is responsible for the modulation of different signalling pathways, which allows the LSC fraction to evade cell death. Several pathways have been shown to be modulated by BCR-ABL, including PI3K/AKT/mTOR, JAK-STAT and autophagy signalling pathways. Targeting components of these survival pathways, alone or in combination with TKI, therefore represents an attractive potential therapeutic approach for targeting the LSC. However, many pathways are also active in normal stem cells. Therefore, potential targets must be validated to effectively eradicate CML stem cells while sparing normal counterparts. This review summarizes the main pathways modulated in CML stem cells, the recent developments and the use of novel drugs to target components in these pathways which may be used to target the LSC population. Linked Articles This article is part of a themed section on Emerging Therapeutic Aspects in Oncology. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2013.169.issue-8 PMID:23517124

Dendritic cells from CML patients have altered actin organization, reduced antigen processing, and impaired migration.

PubMed

Dong, Rong; Cwynarski, Kate; Entwistle, Alan; Marelli-Berg, Federica; Dazzi, Francesco; Simpson, Elizabeth; Goldman, John M; Melo, Junia V; Lechler, Robert I; Bellantuono, Ilaria; Ridley, Anne; Lombardi, Giovanna

2003-05-01

Chronic myeloid leukemia (CML) is characterized by expression of the BCR-ABL fusion gene that encodes a 210-kDa protein, which is a constitutively active tyrosine kinase. At least 70% of the oncoprotein is localized to the cytoskeleton, and several of the most prominent tyrosine kinase substrates for p210(BCR-ABL) are cytoskeletal proteins. Dendritic cells (DCs) are bone marrow-derived antigen-presenting cells responsible for the initiation of immune responses. In CML patients, up to 98% of myeloid DCs generated from peripheral blood mononuclear cells are BCR-ABL positive. In this study we have compared the morphology and behavior of myeloid DCs derived from CML patients with control DCs from healthy individuals. We show that the actin cytoskeleton and shape of CML-DCs of myeloid origin adherent to fibronectin differ significantly from those of normal DCs. CML-DCs are also defective in processing and presentation of exogenous antigens such as tetanus toxoid. The antigen-processing defect may be a consequence of the reduced capacity of CML-DCs to capture antigen via macropinocytosis or via mannose receptors when compared with DCs generated from healthy individuals. Furthermore, chemokine-induced migration of CML-DCs in vitro was significantly reduced. These observations cannot be explained by a difference in the maturation status of CML and normal DCs, because phenotypic analysis by flow cytometry showed a similar surface expression of maturation makers. Taken together, these results suggest that the defects in antigen processing and migration we have observed in CML-DCs may be related to underlying cytoskeletal changes induced by the p210(BCR-ABL) fusion protein.

Mutations with epigenetic effects in myeloproliferative neoplasms and recent progress in treatment: Proceedings from the 5th International Post-ASH Symposium

PubMed Central

Tefferi, A; Abdel-Wahab, O; Cervantes, F; Crispino, J D; Finazzi, G; Girodon, F; Gisslinger, H; Gotlib, J; Kiladjian, J-J; Levine, R L; Licht, J D; Mullally, A; Odenike, O; Pardanani, A; Silver, R T; Solary, E; Mughal, T

2011-01-01

Immediately following the 2010 annual American Society of Hematology (ASH) meeting, the 5th International Post-ASH Symposium on Chronic Myelogenous Leukemia and BCR-ABL1-Negative Myeloproliferative Neoplasms (MPNs) took place on 7–8 December 2010 in Orlando, Florida, USA. During this meeting, the most recent advances in laboratory research and clinical practice, including those that were presented at the 2010 ASH meeting, were discussed among recognized authorities in the field. The current paper summarizes the proceedings of this meeting in BCR-ABL1-negative MPN. We provide a detailed overview of new mutations with putative epigenetic effects (TET oncogene family member 2 (TET2), additional sex comb-like 1 (ASXL1), isocitrate dehydrogenase (IDH) and enhancer of zeste homolog 2 (EZH2)) and an update on treatment with Janus kinase (JAK) inhibitors, pomalidomide, everolimus, interferon-α, midostaurin and cladribine. In addition, the new ‘Dynamic International Prognostic Scoring System (DIPSS)-plus' prognostic model for primary myelofibrosis (PMF) and the clinical relevance of distinguishing essential thrombocythemia from prefibrotic PMF are discussed. PMID:23471017

SNP array analysis of tyrosine kinase inhibitor-resistant chronic myeloid leukemia identifies heterogeneous secondary genomic alterations

PubMed Central

Müschen, Markus; Kato, Motohiro; Kawamata, Norihiko; Meixel, Antonie; Nowak, Verena; Kim, Han S.; Kang, Sharon; Paquette, Ronald; Chang, Mi-Sook; Thoenissen, Nils H.; Mossner, Max; Hofmann, Wolf-Karsten; Kohlmann, Alexander; Weiss, Tamara; Haferlach, Torsten; Haferlach, Claudia; Koeffler, H. Phillip

2010-01-01

To elucidate whether tyrosine kinase inhibitor (TKI) resistance in chronic myeloid leukemia is associated with characteristic genomic alterations, we analyzed DNA samples from 45 TKI-resistant chronic myeloid leukemia patients with 250K single nucleotide polymorphism arrays. From 20 patients, matched serial samples of pretreatment and TKI resistance time points were available. Eleven of the 45 TKI-resistant patients had mutations of BCR-ABL1, including 2 T315I mutations. Besides known TKI resistance-associated genomic lesions, such as duplication of the BCR-ABL1 gene (n = 8) and trisomy 8 (n = 3), recurrent submicroscopic alterations, including acquired uniparental disomy, were detectable on chromosomes 1, 8, 9, 17, 19, and 22. On chromosome 22, newly acquired and recurrent deletions of the IGLC1 locus were detected in 3 patients, who had previously presented with lymphoid or myeloid blast crisis. This may support a hypothesis of TKI-induced selection of subclones differentiating into immature B-cell progenitors as a mechanism of disease progression and evasion of TKI sensitivity. PMID:19965645

Aclacinomycin A Sensitizes K562 Chronic Myeloid Leukemia Cells to Imatinib through p38MAPK-Mediated Erythroid Differentiation

PubMed Central

Liu, Fu-Hwa; Huang, Yu-Wen; Huang, Huei-Mei

2013-01-01

Expression of oncogenic Bcr-Abl inhibits cell differentiation of hematopoietic stem/progenitor cells in chronic myeloid leukemia (CML). Differentiation therapy is considered to be a new strategy for treating this type of leukemia. Aclacinomycin A (ACM) is an antitumor antibiotic. Previous studies have shown that ACM induced erythroid differentiation of CML cells. In this study, we investigate the effect of ACM on the sensitivity of human CML cell line K562 to Bcr-Abl specific inhibitor imatinib (STI571, Gleevec). We first determined the optimal concentration of ACM for erythroid differentiation but not growth inhibition and apoptosis in K562 cells. Then, pretreatment with this optimal concentration of ACM followed by a minimally toxic concentration of imatinib strongly induced growth inhibition and apoptosis compared to that with simultaneous co-treatment, indicating that ACM-induced erythroid differentiation sensitizes K562 cells to imatinib. Sequential treatment with ACM and imatinib induced Bcr-Abl down-regulation, cytochrome c release into the cytosol, and caspase-3 activation, as well as decreased Mcl-1 and Bcl-xL expressions, but did not affect Fas ligand/Fas death receptor and procaspase-8 expressions. ACM/imatinib sequential treatment-induced apoptosis was suppressed by a caspase-9 inhibitor and a caspase-3 inhibitor, indicating that the caspase cascade is involved in this apoptosis. Furthermore, we demonstrated that ACM induced erythroid differentiation through the p38 mitogen-activated protein kinase (MAPK) pathway. The inhibition of erythroid differentiation by p38MAPK inhibitor SB202190, p38MAPK dominant negative mutant or p38MAPK shRNA knockdown, reduced the ACM/imatinib sequential treatment-mediated growth inhibition and apoptosis. These results suggest that differentiated K562 cells induced by ACM-mediated p38MAPK pathway become more sensitive to imatinib and result in down-regulations of Bcr-Abl and anti-apoptotic proteins, growth inhibition and apoptosis. These results provided a potential management by which ACM might have a crucial impact on increasing sensitivity of CML cells to imatinib in the differentiation therapeutic approaches. PMID:23613979

Aclacinomycin A sensitizes K562 chronic myeloid leukemia cells to imatinib through p38MAPK-mediated erythroid differentiation.

PubMed

Lee, Yueh-Lun; Chen, Chih-Wei; Liu, Fu-Hwa; Huang, Yu-Wen; Huang, Huei-Mei

2013-01-01

Expression of oncogenic Bcr-Abl inhibits cell differentiation of hematopoietic stem/progenitor cells in chronic myeloid leukemia (CML). Differentiation therapy is considered to be a new strategy for treating this type of leukemia. Aclacinomycin A (ACM) is an antitumor antibiotic. Previous studies have shown that ACM induced erythroid differentiation of CML cells. In this study, we investigate the effect of ACM on the sensitivity of human CML cell line K562 to Bcr-Abl specific inhibitor imatinib (STI571, Gleevec). We first determined the optimal concentration of ACM for erythroid differentiation but not growth inhibition and apoptosis in K562 cells. Then, pretreatment with this optimal concentration of ACM followed by a minimally toxic concentration of imatinib strongly induced growth inhibition and apoptosis compared to that with simultaneous co-treatment, indicating that ACM-induced erythroid differentiation sensitizes K562 cells to imatinib. Sequential treatment with ACM and imatinib induced Bcr-Abl down-regulation, cytochrome c release into the cytosol, and caspase-3 activation, as well as decreased Mcl-1 and Bcl-xL expressions, but did not affect Fas ligand/Fas death receptor and procaspase-8 expressions. ACM/imatinib sequential treatment-induced apoptosis was suppressed by a caspase-9 inhibitor and a caspase-3 inhibitor, indicating that the caspase cascade is involved in this apoptosis. Furthermore, we demonstrated that ACM induced erythroid differentiation through the p38 mitogen-activated protein kinase (MAPK) pathway. The inhibition of erythroid differentiation by p38MAPK inhibitor SB202190, p38MAPK dominant negative mutant or p38MAPK shRNA knockdown, reduced the ACM/imatinib sequential treatment-mediated growth inhibition and apoptosis. These results suggest that differentiated K562 cells induced by ACM-mediated p38MAPK pathway become more sensitive to imatinib and result in down-regulations of Bcr-Abl and anti-apoptotic proteins, growth inhibition and apoptosis. These results provided a potential management by which ACM might have a crucial impact on increasing sensitivity of CML cells to imatinib in the differentiation therapeutic approaches.

"Normal" Creatinine Levels Predict Persistent Kidney Injury and Waitlist Mortality in Outpatients with Cirrhosis.

PubMed

Cullaro, Giuseppe; Park, Meyeon; Lai, Jennifer C

2018-04-26

Acute kidney injury (AKI) is a critical determinant of outcomes in hospitalized patients with cirrhosis, but little is known of the impact of AKI in the outpatient setting. We analyzed 385 adult outpatients with cirrhosis listed for liver transplant at a single center; excluded were those with severe hepatic encephalopathy, hepatocellular carcinoma or on hemodialysis. Baseline serum creatinine (bCr) was defined as the lowest value recorded; peak creatinine (pCr) as the highest value; delta creatinine (ΔCr) as pCr minus bCr; AKI as a rise in sCR by ≥0.3 mg/dl from bCr; persistent kidney injury as elevation of sCR by ≥0.3 mg/dl from bCr on each subsequent clinical assessment. Among 385 outpatients with cirrhosis, bCr was ≤0.70, 0.70 - 0.97, and ≥0.97 mg/dL in 28%, 38%, and 34%, respectively. At a median follow-up of 16 (8 - 28) months, 143 (37%) had ≥1 AKI episode, which increased significantly by bCr group (24v.37v.48%, p=0.001). Of these 143 with AKI, 13% developed persistent kidney injury. A multivariable cox-regression analysis highlighted that bCr (HR 2.96) and ΔCr (HR 2.05) were the only factors independently associated with the development of persistent kidney injury [p<0.001]. The likelihood of death/delisting increased by bCr group (14v.19v.28%, p=0.03). A competing risk analysis demonstrated that each 1 mg/dL increase in bCr was independently associated with a 62% higher risk of death/delisting when accounting for transplantation and adjusting for confounders. In conclusion, not only is AKI common in outpatients with cirrhosis, but even "clinically normal" bCr levels significantly impact the risk of persistent kidney injury and waitlist mortality, supporting the need for a lower clinical threshold to initiate monitoring of renal function and implementation of renal-protective strategies. This article is protected by copyright. All rights reserved. © 2018 by the American Association for the Study of Liver Diseases.

DNA damage, lysosomal degradation and Bcl-xL deamidation in doxycycline- and minocycline-induced cell death in the K562 leukemic cell line.

PubMed

Fares, Mona; Abedi-Valugerdi, Manuchehr; Hassan, Moustapha; Potácová, Zuzana

2015-07-31

We investigated mechanisms of cytotoxicity induced by doxycycline (doxy) and minocycline (mino) in the chronic myeloid leukemia K562 cell line. Doxy and mino induced cell death in exposure-dependent manner. While annexin V/propidium iodide staining was consistent with apoptosis, the morphological changes in Giemsa staining were more equivocal. A pancaspase inhibitor Z-VAD-FMK partially reverted cell death morphology, but concurrently completely prevented PARP cleavage. Mitochondrial involvement was detected as dissipation of mitochondrial membrane potential and cytochrome C release. DNA double strand breaks detected with γH2AX antibody and caspase-2 activation were found early after the treatment start, but caspase-3 activation was a late event. Decrement of Bcl-xL protein levels and electrophoretic shift of Bcl-xL molecule were induced by both drugs. Phosphorylation of Bcl-xL at serine 62 was ruled out. Similarly, Bcr/Abl tyrosine kinase levels were decreased. Lysosomal inhibitor chloroquine restored Bcl-xL and Bcr/Abl protein levels and inhibited caspase-3 activation. Thus, the cytotoxicity of doxy and mino in K562 cells is mediated by DNA damage, Bcl-xL deamidation and lysosomal degradation with activation of mitochondrial pathway of apoptosis. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Blinatumomab and Combination Chemotherapy or Dasatinib, Prednisone, and Blinatumomab in Treating Older Patients With Acute Lymphoblastic Leukemia

ClinicalTrials.gov

2018-06-01

Acute Lymphoblastic Leukemia; B Acute Lymphoblastic Leukemia; B Acute Lymphoblastic Leukemia With t(9;22)(q34.1;q11.2); BCR-ABL1; B Acute Lymphoblastic Leukemia, Philadelphia Chromosome Negative; Philadelphia Chromosome Positive; Recurrent Adult Acute Lymphoblastic Leukemia; Refractory Adult Acute Lymphoblastic Leukemia; Untreated Adult Acute Lymphoblastic Leukemia

Chronic Lymphocytic Leukemia-Derived IL-10 Suppresses Antitumor Immunity.

PubMed

Alhakeem, Sara S; McKenna, Mary K; Oben, Karine Z; Noothi, Sunil K; Rivas, Jacqueline R; Hildebrandt, Gerhard C; Fleischman, Roger A; Rangnekar, Vivek M; Muthusamy, Natarajan; Bondada, Subbarao

2018-04-30

Chronic lymphocytic leukemia (CLL) patients progressively develop an immunosuppressive state. CLL patients have more plasma IL-10, an anti-inflammatory cytokine, than healthy controls. In vitro human CLL cells produce IL-10 in response to BCR cross-linking. We used the transgenic Eμ-T cell leukemia oncogene-1 ( TCL1 ) mouse CLL model to study the role of IL-10 in CLL associated immunosuppression. Eμ-TCL mice spontaneously develop CLL because of a B cell-specific expression of the oncogene, TCL1. Eμ- TCL1 mouse CLL cells constitutively produce IL-10, which is further enhanced by BCR cross-linking, CLL-derived IL-10 did not directly affect survival of murine or human CLL cells in vitro. We tested the hypothesis that the CLL-derived IL-10 has a critical role in CLL disease in part by suppressing the host immune response to the CLL cells. In IL-10R -/- mice, wherein the host immune cells are unresponsive to IL-10-mediated suppressive effects, there was a significant reduction in CLL cell growth compared with wild type mice. IL-10 reduced the generation of effector CD4 and CD8 T cells. We also found that activation of BCR signaling regulated the production of IL-10 by both murine and human CLL cells. We identified the transcription factor, Sp1, as a novel regulator of IL-10 production by CLL cells and that it is regulated by BCR signaling via the Syk/MAPK pathway. Our results suggest that incorporation of IL-10 blocking agents may enhance current therapeutic regimens for CLL by potentiating host antitumor immune response. Copyright © 2018 by The American Association of Immunologists, Inc.

CXCL12 promoter methylation and PD-L1 expression as prognostic biomarkers in prostate cancer patients.

PubMed

Goltz, Diane; Holmes, Emily Eva; Gevensleben, Heidrun; Sailer, Verena; Dietrich, Jörn; Jung, Maria; Röhler, Magda; Meller, Sebastian; Ellinger, Jörg; Kristiansen, Glen; Dietrich, Dimo

2016-08-16

The CXCR4/CXCL12 axis plays a central role in systemic metastasis of prostate carcinoma (PCa), thereby representing a promising target for future therapies. Recent data suggest that the CXCR4/CXCL12 axis is functionally linked to the PD-1/PD-L1 immune checkpoint. We evaluated the prognostic value of aberrant CXCL12 DNA methylation with respect to PD-L1 expression in primary PCa. CXCL12 methylation showed a consistent significant correlation with Gleason grading groups in both cohorts (p < 0.001 for training and p = 0.034 for testing cohort). Short BCR-free survival was significantly associated with aberrant CXCL12 methylation in both cohorts and served as an independent prognostic factor in the testing cohort (hazard ratio = 1.92 [95%CI: 1.12-3.27], p = 0.049). Concomitant aberrant CXCL12 methylation and high PD-L1 expression was significantly associated with shorter BCR-free survival (p = 0.005). In comparative analysis, the CXCL12 methylation assay was able to provide approximately equivalent results in biopsy and prostatectomy specimens. CXCL12 methylation was determined by means of a methylation specific quantitative PCR analysis in a radical prostatectomy patient cohort (n = 247, training cohort). Data published by The Cancer Genome Atlas served as a testing cohort (n = 498). CXCL12 methylation results were correlated to clinicopathological parameters including biochemical recurrence (BCR)-free survival. CXCL12 methylation is a powerful prognostic biomarker for BCR in PCa patients after radical prostatectomy. Further studies need to ascertain if CXCL12 methylation may aid in planning active surveillance strategies.

Clinical roundtable monograph: Emerging treatment options for TKI-resistant chronic myelogenous leukemia.

PubMed

Cortes, Jorge; Radich, Jerald; Mauro, Michael J

2012-10-01

The development of tyrosine kinase inhibitors (TKIs) that inhibit signaling of the constitutive BCR-ABL protein revolutionized the treatment of chronic myelogenous leukemia (CML). These agents have dramatically changed the treatment landscape for CML, shifting the use of allogeneic stem cell transplantation to selected patients in the salvage setting. Four BCR-ABL TKIs are now commercially available for the treatment of CML: the first-generation TKI imatinib, and the second-generation TKIs dasatinib, nilotinib, and bosutinib. Continuous treatment with these agents induces durable responses in a high proportion of patients with chronic-phase CML. Research is focused on identifying which patients can discontinue therapy without a recurrence of disease. For the group of patients with resistance to TKIs, multiple alternative therapies are being evaluated. The third-generation TKI ponatinib is a BCR-ABL inhibitor that has demonstrated significant activity, including in patients with the TKI resistance mutation T315I. The homoharringtonine derivative omacetaxine mepesuccinate, which inhibits protein synthesis, has also demonstrated clinical activity in CML, including in patients with TKI resistance due to T315I and in patients who have TKI resistance despite no evidence of ABL mutations. It is essential that clinicians implement these new agents with care and change therapies only when appropriate in order to preserve as many options as possible for future use if needed.

Combination of low-dose imatinib plus nilotinib for the treatment of chronic-phase chronic myeloid leukaemia after imatinib failure.

PubMed

Gómez-Almaguer, David; Saldaña-Vázquez, Roxana; Tarín-Arzaga, Luz; Herrera-Rojas, Miguel Angel; Vázquez-Mellado de Larracoechea, Alberto; Cantú-Rodríguez, Olga Graciela; Gutiérrez-Aguirre, Cesar Homero; Jaime-Pérez, José Carlos

2016-08-01

This is a feasibility study to evaluate whether simultaneous administration of low doses of imatinib and nilotinib in chronic-phase chronic myeloid leukaemia (CP-CML) patients has the potential for transcript elimination after failure to imatinib. Ten patients were enrolled; eight had cytogenetic relapse and two had confirmed loss of major molecular response (MMR). At baseline, BCR-ABL kinase domain mutation was detected in four patients. After 6 months of therapy, major cytogenetic response, complete cytogenetic response, and MMR were achieved in seven, four, and four patients, respectively. Grade 4 thrombocytopenia developed in one patient, and grade 1 skin rash in four. These results suggest that imatinib might have inhibitory effects on the clearance of nilotinib, increasing its efficacy. This dual therapy was well tolerated and resulted in improvement of cytogenetic and molecular responses in patients with CP-CML after failure to imatinib. ClinicalTrials.gov registration number: NCT01819389.

Genetic Polymorphisms of Hemostatic Factors and Thrombotic Risk in Non BCR-ABL Myeloproliferative Neoplasms: A Pilot Study

PubMed Central

Dambrauskienė, R; Gerbutavičius, R; Ugenskienė, R; Jankauskaitė, R; Savukaitytė, A; Šimoliūnienė, R; Rudžianskienė, M; Gerbutavičienė, R; Juozaitytė, E

2017-01-01

Abstract The most important complications of Philadelphianegagive (non BCR-ABL) myeloproliferative neoplasms (MPNs) are vascular events. Our aim was to evaluate the effects of single nucleotide polymorphisms (SNPs), platelet glycoproteins (GPs) (Ia/IIa, Ibα, IIb/IIIa and VI), von Willebrand factor (vWF), coagulation factor VII (FVII), β-fibrinogen, and the risk of thrombosis in patients with non BCR-ABL MPNs at the Lithuanian University of Health Sciences. Kaunas, Lithuania. Genotyping was done for 108 patients. The TT genotype of the GP Ia/IIa c.807C>T polymorphism was more frequently found in the group of MPN patients with arterial thrombosis compared to MPN patients who were thrombosis-free [26.5 vs. 11.5%, p = 0.049; odds ratio (OR) 2.68; 95% confidence interval (95% CI) 1.01-7.38]. The CT genotype of the β-fibrinogen c.-148C>T polymorphism occurred more frequently in MPN patients with arterial, and total thrombosis compared to the wild or homozygous genotype (57.7 vs. 40.0 vs. 12.5%; p = 0.027), (64.7 vs. 44.4 vs. 25%; p = 0.032), respectively. The carrier state for the c.-323P10 variant of FVII SNP (summation of P10/10 and P0/10) was more frequent in MPN patients with thrombosis compared to the wild-type genotype carriers (71.4 vs. 43.4%; p = 0.049; OR 3.26; 95% CI 1.01-11.31). The coexistence of heterozygous β-fibrinogen c.-148C>T and FVII c.-323P0/10 SNP, increased the risk of arterial thrombosis (21.1 vs. 3.7%, p = 0.008; OR 6.93; 95% CI 1.38-34.80). The TT genotype of GP Ia/IIa c.807C>T, the CT genotype of β-fibrinogen c.-148C>T and FVII c.-323P0/10 SNP could be associated with risk of thrombosis in MPN patients. PMID:28924539

Leukotriene signaling via ALOX5 and cysteinyl leukotriene receptor 1 is dispensable for in vitro growth of CD34+CD38- stem and progenitor cells in chronic myeloid leukemia.

PubMed

Dolinska, Monika; Piccini, Alexandre; Wong, Wan Man; Gelali, Eleni; Johansson, Anne-Sofie; Klang, Johannis; Xiao, Pingnan; Yektaei-Karin, Elham; Strömberg, Ulla Olsson; Mustjoki, Satu; Stenke, Leif; Ekblom, Marja; Qian, Hong

2017-08-19

Tyrosine kinase inhibitors targeting the BCR-ABL oncoprotein in chronic myeloid leukemia (CML) are remarkably effective inducing deep molecular remission in most patients. However, they are less effective to eradicate the leukemic stem cells (LSC), resulting in disease persistence. Therefore, there is great need to develop novel therapeutic strategies to specifically target the LSC. In an experimental mouse CML model system, the leukotriene pathway, and specifically, the expression ALOX5, encoding 5-lipoxygenase (5-LO), has been reported as a critical regulator of the LSC. Based on these results, the 5-LO inhibitor zileuton has been introduced in clinical trials as a therapeutic option to target the LSC although its effect on primary human CML LSC has not been studied. We have here by using multiplex single cell PCR analyzed the expression of the mediators of the leukotriene pathway in bone marrow (BM) BCR-ABL + CD34 + CD38 - cells at diagnosis, and found low or undetectable expression of ALOX5. In line with this, zileuton did not exert significant overall growth inhibition in the long-term culture-initiating cell (LTC-IC) and colony (CFU-C) assays of BM CD34 + CD38 - cells from 7 CML patients. The majority of the single leukemic BCR-ABL + CD34 + CD38 - cells expressed cysteinyl leukotriene receptors CYSLT1 and CYSLT2. However, montelukast, an inhibitor of CYSLT1, also failed to significantly suppress CFU-C and LTC-IC growth. These findings indicate that targeting ALOX5 or CYSLT1 signaling with leukotriene antagonists, introduced into the clinical practice primarily as prophylaxis and treatment for asthma, may not be a promising pharmacological strategy to eradicate persisting LSC in CML patients. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

CD22 regulates adaptive and innate immune responses of B cells.

PubMed

Kawasaki, Norihito; Rademacher, Christoph; Paulson, James C

2011-01-01

B cells sense microenvironments through the B cell receptor (BCR) and Toll-like receptors (TLRs). While signals from BCR and TLRs synergize to distinguish self from nonself, inappropriate regulation can result in development of autoimmune disease. Here we show that CD22, an inhibitory co-receptor of BCR, also negatively regulates TLR signaling in B cells. CD22-deficient (Cd22(-/-)) B cells exhibit hyperactivation in response to ligands of TLRs 3, 4 and 9. Evidence suggests that this results from impaired induction of suppressors of cytokine signaling 1 and 3, well-known suppressors of TLR signaling. Antibody-mediated sequestration of CD22 on wild-type (WT) B cells augments proliferation by TLR ligands. Conversely, expression of CD22 in a Cd22(-/-) B cell line blunts responses to TLR ligands. We also show that lipopolysaccharide-induced transcription by nuclear factor-κB is inhibited by ectopic expression of CD22 in a TLR4 reporter cell line. Taken together, these results suggest that negative regulation of TLR signaling is an intrinsic property of CD22. Since TLRs and BCR activate B cells through different signaling pathways, and are differentially localized in B cells, CD22 exhibits a broader regulation of receptors that mediate adaptive and innate immune responses of B cells than previously recognized. Copyright © 2010 S. Karger AG, Basel.

Dynamic Control of Excitatory Synapse Development by a Rac1 GEF/GAP Regulatory Complex

PubMed Central

Um, Kyongmi; Niu, Sanyong; Duman, Joseph G.; Cheng, Jinxuan; Tu, Yen-Kuei; Schwechter, Brandon; Liu, Feng; Hiles, Laura; Narayanan, Anjana; Ash, Ryan T.; Mulherkar, Shalaka; Alpadi, Kannan; Smirnakis, Stelios M.; Tolias, Kimberley F.

2014-01-01

SUMMARY The small GTPase Rac1 orchestrates actin-dependent remodeling essential for numerous cellular processes including synapse development. While precise spatiotemporal regulation of Rac1 is necessary for its function, little is known about the mechanisms that enable Rac1 activators (GEFs) and inhibitors (GAPs) to act in concert to regulate Rac1 signaling. Here we identify a regulatory complex composed of a Rac-GEF (Tiam1) and a Rac-GAP (Bcr) that cooperate to control excitatory synapse development. Disruption of Bcr function within this complex increases Rac1 activity and dendritic spine remodeling, resulting in excessive synaptic growth that is rescued by Tiam1 inhibition. Notably, EphB receptors utilize the Tiam1-Bcr complex to control synaptogenesis. Following EphB activation, Tiam1 induces Rac1-dependent spine formation, whereas Bcr prevents Rac1-mediated receptor internalization, promoting spine growth over retraction. The finding that a Rac-specific GEF/GAP complex is required to maintain optimal levels of Rac1 signaling provides an important insight into the regulation of small GTPases. PMID:24960694

MicroRNAs in B-cell lymphomas: how a complex biology gets more complex.

PubMed

Musilova, K; Mraz, M

2015-05-01

MicroRNAs (miRNAs) represent important regulators of gene expression besides transcriptional control. miRNA regulation can be involved in the cell developmental fate decisions, but can also have more subtle roles in buffering stochastic fluctuations in gene expression. They participate in pathways fundamental to B-cell development like B-cell receptor (BCR) signalling, B-cell migration/adhesion, cell-cell interactions in immune niches, and the production and class-switching of immunoglobulins. miRNAs influence B-cell maturation, generation of pre-, marginal zone, follicular, B1, plasma and memory B cells. In this review, we discuss miRNAs with essential functions in malignant B-cell development (such as miR-150, miR-155, miR-21, miR-34a, miR-17-92 and miR-15-16). We also put these miRNAs in the context of normal B-cell differentiation, as this is intimately connected to neoplastic B-cell development. We review miRNAs' role in the most common B-cell malignancies, including chronic lymphocytic leukaemia (CLL), diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) and mantle cell lymphoma (MCL). We focus on miR-contribution to the regulation of important signalling pathways (such as NF-κB, PI3K/AKT and TGF-β), BCR signalling and its modulators (such as PTEN, SHIP-1, ZAP-70, GAB1 and BTK), anti- and pro-apoptotic proteins (such as BCL2, MCL1, TCL1, BIM, p53 and SIRT1) and transcription factors (such as MYC, MYB, PU.1, FOXP1 and BCL6). We also discuss the association of miRNAs' expression levels with the patients' survival and response to therapy, summarizing their potential use as predictive and prognostic markers. Importantly, the targeting of miRNAs (like use of anti-miR-155 or miR-34a mimic) could provide a novel therapeutic approach as evidenced by tumour regression in xenograft mouse models and initial promising data from clinical trials.

Potent Activity of Ponatinib (AP24534) in Models of FLT3-Driven Acute Myeloid Leukemia and Other Hematologic Malignancies

PubMed Central

Gozgit, Joseph M.; Wong, Matthew J.; Wardwell, Scott; Tyner, Jeffrey W.; Loriaux, Marc M.; Mohemmad, Qurish K.; Narasimhan, Narayana I.; Shakespeare, William C.; Wang, Frank; Druker, Brian J.; Clackson, Tim; Rivera, Victor M.

2011-01-01

Ponatinib (AP24534) is a novel multitargeted kinase inhibitor that potently inhibits native and mutant BCR-ABL at clinically achievable drug levels. Ponatinib also has in vitro inhibitory activity against a discrete set of kinases implicated in the pathogenesis of other hematologic malignancies, including FLT3, KIT, fibroblast growth factor receptor 1 (FGFR1), and platelet derived growth factor receptor α (PDGFRα). Here, using leukemic cell lines containing activated forms of each of these receptors, we show that ponatinib potently inhibits receptor phosphorylation and cellular proliferation with IC50 values comparable to those required for inhibition of BCR-ABL (0.3 to 20 nmol/L). The activity of ponatinib against the FLT3-ITD mutant, found in up to 30% of acute myeloid leukemia (AML) patients, was particularly notable. In MV4-11 (FLT3-ITD+/+) but not RS4;11 (FLT3-ITD−/−) AML cells, ponatinib inhibited FLT3 signaling and induced apoptosis at concentrations of less than 10 nmol/L. In an MV4-11 mouse xenograft model, once daily oral dosing of ponatinib led to a dose-dependent inhibition of signaling and tumor regression. Ponatinib inhibited viability of primary leukemic blasts from a FLT3-ITD positive AML patient (IC50 4 nmol/L) but not those isolated from 3 patients with AML expressing native FLT3. Overall, these results support the investigation of ponatinib in patients with FLT3-ITD–driven AML and other hematologic malignancies driven by KIT, FGFR1, or PDGFRα. PMID:21482694

Evaluation of Serum Calcium as a Predictor of Biochemical Recurrence following Salvage Radiation Therapy for Prostate Cancer

PubMed Central

Peterson, Jennifer L.; Buskirk, Steven J.; Heckman, Michael G.; Parker, Alexander S.; Diehl, Nancy N.; Tzou, Katherine S.; Paryani, Nitesh N.; Ko, Stephen J.; Daugherty, Larry C.; Vallow, Laura A.; Pisansky, Thomas M.

2013-01-01

Background. Previous reports have shown a positive association between serum calcium level and prostate cancer mortality. However, there is no data regarding whether higher serum calcium levels are associated with increased risk of biochemical recurrence (BCR) following salvage radiation therapy (SRT) for prostate cancer. Herein, we evaluate the association between pretreatment serum calcium levels and BCR in a cohort of men who underwent SRT. Methods. We evaluated 165 patients who underwent SRT at our institution. Median dose was 65.0 Gy (range: 54.0–72.4 Gy). We considered serum calcium as both a continuous variable and a 3-level categorical variable (low [≤9.0 mg/dL], moderate [>9.0 mg/dL and ≤9.35 mg/dL], and high [>9.35 mg/dL]) based on sample tertiles. Results. We observed no evidence of a linear association between serum calcium and BCR (relative risk (RR): 0.96, P = 0.76). Compared to men with low calcium, there was no significantly increased risk of BCR for men with moderate (RR: 0.94, P = 0.79) or high (RR: 1.08, P = 0.76) serum calcium levels. Adjustment for clinical, pathological, and SRT characteristics in multivariable analyses did not alter these findings. Conclusion. Our results provide evidence that pretreatment serum calcium is unlikely to be a useful tool in predicting BCR risk following SRT. PMID:23606986

Management of Platelet Transfusion Therapy in Patients With Blood Cancer or Treatment-Induced Thrombocytopenia

ClinicalTrials.gov

2018-02-15

Acute Biphenotypic Leukemia; Acute Lymphoblastic Leukemia; Acute Myeloid Leukemia; B-Cell Non-Hodgkin Lymphoma; Chronic Lymphocytic Leukemia; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Hematologic and Lymphocytic Disorder; Hematopoietic Cell Transplantation Recipient; Myelodysplastic Syndrome; Primary Myelofibrosis; Secondary Myelofibrosis; T-Cell Non-Hodgkin Lymphoma; Thrombocytopenia; Venous Thromboembolism

3-AP and Fludarabine in Treating Patients With Myeloproliferative Disorders, Chronic Myelomonocytic Leukemia, or Accelerated Phase or Blastic Phase Chronic Myelogenous Leukemia

ClinicalTrials.gov

2014-12-16

Accelerated Phase Chronic Myelogenous Leukemia; Atypical Chronic Myeloid Leukemia, BCR-ABL1 Negative; Blastic Phase Chronic Myelogenous Leukemia; Chronic Eosinophilic Leukemia; Chronic Myelomonocytic Leukemia; Essential Thrombocythemia; Philadelphia Chromosome Negative Chronic Myelogenous Leukemia; Polycythemia Vera; Primary Myelofibrosis; Relapsing Chronic Myelogenous Leukemia

Topotecan Hydrochloride and Carboplatin With or Without Veliparib in Treating Advanced Myeloproliferative Disorders and Acute Myeloid Leukemia or Chronic Myelomonocytic Leukemia

ClinicalTrials.gov

2018-06-22

Acute Myeloid Leukemia; Acute Myeloid Leukemia Arising From Previous Myelodysplastic Syndrome; Atypical Chronic Myeloid Leukemia, BCR-ABL1 Negative; Chronic Myelomonocytic Leukemia; Essential Thrombocythemia; Myelodysplastic/Myeloproliferative Neoplasm; Myelofibrosis; Polycythemia Vera; Recurrent Adult Acute Myeloid Leukemia; Refractory Acute Myeloid Leukemia

Enhanced SH3/Linker Interaction Overcomes Abl Kinase Activation by Gatekeeper and Myristic Acid Binding Pocket Mutations and Increases Sensitivity to Small Molecule Inhibitors*

PubMed Central

Panjarian, Shoghag; Iacob, Roxana E.; Chen, Shugui; Wales, Thomas E.; Engen, John R.; Smithgall, Thomas E.

2013-01-01

Multidomain kinases such as c-Src and c-Abl are regulated by complex allosteric interactions involving their noncatalytic SH3 and SH2 domains. Here we show that enhancing natural allosteric control of kinase activity by SH3/linker engagement has long-range suppressive effects on the kinase activity of the c-Abl core. Surprisingly, enhanced SH3/linker interaction also dramatically sensitized the Bcr-Abl tyrosine kinase associated with chronic myelogenous leukemia to small molecule inhibitors that target either the active site or the myristic acid binding pocket in the kinase domain C-lobe. Dynamics analyses using hydrogen exchange mass spectrometry revealed a remarkable allosteric network linking the SH3 domain, the myristic acid binding pocket, and the active site of the c-Abl core, providing a structural basis for the biological observations. These results suggest a rational strategy for enhanced drug targeting of Bcr-Abl and other multidomain kinase systems that use multiple small molecules to exploit natural mechanisms of kinase control. PMID:23303187

CRISPR-Cas9-mediated saturated mutagenesis screen predicts clinical drug resistance with improved accuracy.

PubMed

Ma, Leyuan; Boucher, Jeffrey I; Paulsen, Janet; Matuszewski, Sebastian; Eide, Christopher A; Ou, Jianhong; Eickelberg, Garrett; Press, Richard D; Zhu, Lihua Julie; Druker, Brian J; Branford, Susan; Wolfe, Scot A; Jensen, Jeffrey D; Schiffer, Celia A; Green, Michael R; Bolon, Daniel N

2017-10-31

Developing tools to accurately predict the clinical prevalence of drug-resistant mutations is a key step toward generating more effective therapeutics. Here we describe a high-throughput CRISPR-Cas9-based saturated mutagenesis approach to generate comprehensive libraries of point mutations at a defined genomic location and systematically study their effect on cell growth. As proof of concept, we mutagenized a selected region within the leukemic oncogene BCR-ABL1 Using bulk competitions with a deep-sequencing readout, we analyzed hundreds of mutations under multiple drug conditions and found that the effects of mutations on growth in the presence or absence of drug were critical for predicting clinically relevant resistant mutations, many of which were cancer adaptive in the absence of drug pressure. Using this approach, we identified all clinically isolated BCR-ABL1 mutations and achieved a prediction score that correlated highly with their clinical prevalence. The strategy described here can be broadly applied to a variety of oncogenes to predict patient mutations and evaluate resistance susceptibility in the development of new therapeutics. Published under the PNAS license.

SRC-like adaptor protein regulates B cell development and function.

PubMed

Dragone, Leonard L; Myers, Margaret D; White, Carmen; Sosinowski, Tomasz; Weiss, Arthur

2006-01-01

The avidity of BCRs and TCRs influences signal strength during processes of lymphocyte development. Avidity is determined by both the intrinsic affinity for Ag and surface levels of the Ag receptor. The Src-like adaptor protein (SLAP) is a regulator of TCR levels on thymocytes, and its deficiency alters thymocyte development. We hypothesized that SLAP, which is expressed in B cells, also is important in regulating BCR levels, signal strength, and B cell development. To test this hypothesis, we analyzed the B cell compartment in SLAP-deficient mice. We found increased splenic B cell numbers and decreased surface IgM levels on mature, splenic B cells deficient in SLAP. Immature bone marrow and splenic B cells from BCR-transgenic, SLAP-deficient mice were found to express higher surface levels of IgM. In contrast, mature splenic B cells from BCR-transgenic mice expressed decreased levels of surface BCR associated with decreased calcium flux and activation-induced markers, compared with controls. These data suggest that SLAP regulates BCR levels and signal strength during lymphocyte development.

Sapanisertib in Treating Patients With Relapsed and/or Refractory Acute Lymphoblastic Leukemia

ClinicalTrials.gov

2018-05-23

Acute Lymphoblastic Leukemia in Remission; B Acute Lymphoblastic Leukemia; B Acute Lymphoblastic Leukemia With t(9;22)(q34.1;q11.2); BCR-ABL1; B Acute Lymphoblastic Leukemia, Philadelphia Chromosome Negative; Blasts 10 Percent or More of Bone Marrow Nucleated Cells; Recurrent Adult Acute Lymphoblastic Leukemia; Refractory Adult Acute Lymphoblastic Leukemia; T Acute Lymphoblastic Leukemia

Development of t(8;21) and RUNX1-RUNX1T1 in the Philadelphia-positive clone of a patient with chronic myelogenous leukemia: additional evidence for multiple steps involved in disease progression.

PubMed

Najfeld, Vesna; Wisch, Nathaniel; Mascarenhas, John; Issa, Leonard; Tripodi, Joseph; Sidhu, Manpreet; Hoffman, Ronald

2011-03-01

A 65-year-old patient with a high hemoglobin and hematocrit was treated for 14 months with therapeutic phlebotomy when cytogenetics of bone marrow revealed 100% cells with the Ph chromosome and 45% of the Ph+ cells contained trisomy 8. Treatment with tyrosine kinase inhibitors did not reduce the BCR-ABL1 fusion positive clone. Instead, the Ph positive cells acquired further the t(8;21)/RUNX1-RUNX1T1, del(4q) and trisomy 15 chromosomal abnormalities which were resistant to further treatment. Literature review revealed eight other patients who either had t(9;22) and t(8;21) simultaneously or developed t(8;21) in the Ph positive clone. We conclude that there are rare patients with CML who either present in blast crisis with coexistence of t(9;22) and t(8;21) with or without +8, or progress to blast crisis with acquiring RUNX1-RUNX1T1 in the BCR-ABL1 clone which may or may not be therapy related and represent a later event in a multistep pathogenesis. Copyright © 2011 Elsevier Inc. All rights reserved.

Combination Chemotherapy With or Without Donor Stem Cell Transplant in Treating Patients With Acute Lymphoblastic Leukemia

ClinicalTrials.gov

2018-04-20

Acute Lymphoblastic Leukemia; Adult Acute Lymphoblastic Leukemia in Remission; Adult B Acute Lymphoblastic Leukemia; Adult B Acute Lymphoblastic Leukemia With t(9;22)(q34.1;q11.2); BCR-ABL1; Adult L1 Acute Lymphoblastic Leukemia; Adult L2 Acute Lymphoblastic Leukemia; Adult T Acute Lymphoblastic Leukemia; Recurrent Adult Acute Lymphoblastic Leukemia; Untreated Adult Acute Lymphoblastic Leukemia

Sensitivity of imatinib-resistant T315I BCR-ABL CML to a synergistic combination of ponatinib and forskolin treatment.

PubMed

Oaxaca, Derrick M; Yang-Reid, Sun Ah; Ross, Jeremy A; Rodriguez, Georgialina; Staniswalis, Joan G; Kirken, Robert A

2016-09-01

Tyrosine kinase inhibitors (TKIs) have dramatically improved the life expectancy of patients suffering from chronic myeloid leukemia (CML); however, patients will eventually develop resistance to TKI therapy or adverse side effects due to secondary off-target mechanisms associated with TKIs. CML patients exhibiting TKI resistance are at greater risk of developing an aggressive and drug-insensitive disease. Drug-resistant CML typically arises in response to spontaneous mutations within the drug binding sites of the targeted oncoproteins. To better understand the mechanism of drug resistance in TKI-resistant CML patients, the BCR-ABL transformed cell line KCL22 was grown with increasing concentrations of imatinib for a period of 6 weeks. Subsequently, a drug-resistant derivative of the parental KCL22 cell line harboring the T315I gatekeeper mutation was isolated and investigated for TKI drug sensitivity via multi-agent drug screens. A synergistic combination of ponatinib- and forskolin-reduced cell viability was identified in this clinically relevant imatinib-resistant CML cell line, which also proved efficacious in other CML cell lines. In summary, this study provides new insight into the biological underpinnings of BCR-ABL-driven CML and potential rationale for investigating novel treatment strategies for patients with T315I CML.

Stage-specific control of early B cell development by the transcription factor Ikaros

PubMed Central

Gültekin, Sinan; Dakic, Aleksandar; Axelsson, Elin; Minnich, Martina; Ebert, Anja; Werner, Barbara; Roth, Mareike; Cimmino, Luisa; Dickins, Ross A.; Zuber, Johannes; Jaritz, Markus; Busslinger, Meinrad

2018-01-01

Ikaros is an essential regulator of lymphopoiesis. Here, we studied the B-cell-specific function of Ikaros by conditional Ikzf1 inactivation in pro-B cells. B-cell development was arrested at an aberrant ‘pro-B’ cell stage characterized by increased cell adhesion and loss of pre-B cell receptor signaling. Ikaros was found to activate genes coding for pre-BCR signal transducers and to repress genes involved in the downregulation of pre-BCR signaling and upregulation of the integrin signaling pathway. Unexpectedly, derepression of Aiolos expression could not compensate for the loss of Ikaros in pro-B cells. Ikaros induced or suppressed active chromatin at regulatory elements of activated or repressed target genes. Notably, Ikaros binding and target gene expression was dynamically regulated at distinct stages of early B-lymphopoiesis. PMID:24509509

Bacterial GtfB Augments Candida albicans Accumulation in Cross-Kingdom Biofilms.

PubMed

Ellepola, K; Liu, Y; Cao, T; Koo, H; Seneviratne, C J

2017-09-01

Streptococcus mutans is a biofilm-forming oral pathogen commonly associated with dental caries. Clinical studies have shown that S. mutans is often detected with Candida albicans in early childhood caries. Although the C. albicans presence has been shown to enhance bacterial accumulation in biofilms, the influence of S. mutans on fungal biology in this mixed-species relationship remains largely uncharacterized. Therefore, we aimed to investigate how the presence of S. mutans influences C. albicans biofilm development and coexistence. Using a newly established haploid biofilm model of C. albicans, we found that S. mutans augmented haploid C. albicans accumulation in mixed-species biofilms. Similarly, diploid C. albicans also showed enhanced biofilm formation in the presence of S. mutans. Surprisingly, the presence of S. mutans restored the biofilm-forming ability of C. albicans bcr1Δ mutant and bcr1Δ/Δ mutant, which is known to be severely defective in biofilm formation when grown as single species. Moreover, C. albicans hyphal growth factor HWP1 as well as ALS1 and ALS3, which are also involved in fungal biofilm formation, were upregulated in the presence of S. mutans. Subsequently, we found that S. mutans-derived glucosyltransferase B (GtfB) itself can promote C. albicans biofilm development. Interestingly, GtfB was able to increase the expression of HWP1, ALS1, and ALS3 genes in the C. albicans diploid wild-type SC5314 and bcr1Δ/Δ, leading to enhanced fungal biofilms. Hence, the present study demonstrates that a bacterial exoenzyme (GtfB) augments the C. albicans counterpart in mixed-species biofilms through a BCR1-independent mechanism. This novel finding may explain the mutualistic role of S. mutans and C. albicans in cariogenic biofilms.

Ibrutinib inhibits pre-BCR+ B-cell acute lymphoblastic leukemia progression by targeting BTK and BLK

PubMed Central

Kim, Ekaterina; Hurtz, Christian; Koehrer, Stefan; Wang, Zhiqiang; Balasubramanian, Sriram; Chang, Betty Y.; Müschen, Markus; Davis, R. Eric

2017-01-01

Targeting B-cell receptor (BCR) signaling is a successful therapeutic strategy in mature B-cell malignancies. Precursor BCR (pre-BCR) signaling, which is critical during normal B lymphopoiesis, also plays an important role in pre-BCR+ B cell acute lymphoblastic leukemia (B-ALL). Here, we investigated the activity and mechanism of action of the BTK inhibitor ibrutinib in preclinical models of B-ALL. Pre-BCR+ ALL cells were exquisitely sensitive to ibrutinib at therapeutically relevant drug concentrations. In pre-BCR+ ALL, ibrutinib thwarted autonomous and induced pre-BCR signaling, resulting in deactivation of PI3K/Akt signaling. Ibrutinib modulated the expression of pre-BCR regulators (PTPN6, CD22, CD72, and PKCβ) and substantially reduced BCL6 levels. Ibrutinib inhibited ALL cell migration toward CXCL12 and beneath marrow stromal cells and reduced CD44 expression. CRISPR-Cas9 gene editing revealed that both BTK and B lymphocyte kinase (BLK) are relevant targets of ibrutinib in pre-BCR+ ALL. Consequently, in mouse xenograft models of pre-BCR+ ALL, ibrutinib treatment significantly prolonged survival. Combination treatment of ibrutinib with dexamethasone or vincristine demonstrated synergistic activity against pre-BCR+ ALL. These data corroborate ibrutinib as a promising targeted agent for pre-BCR+ ALL and highlight the importance of ibrutinib effects on alternative kinase targets. PMID:28031181

Using benefit-cost ratio to select Universal Newborn Hearing Screening test criteria.

PubMed

Porter, Heather L; Neely, Stephen T; Gorga, Michael P

2009-08-01

Current protocols presumably use criteria that are chosen on the basis of the sensitivity and specificity rates they produce. Such an approach emphasizes test performance but does not include societal implications of the benefit of early identification. The purpose of the present analysis was to evaluate an approach to selecting criteria for use in Universal Newborn Hearing Screening (UNHS) programs that uses benefit-cost ratio (BCR) to demonstrate an alternative method to audiologists, administrators, and others involved in UNHS protocol decisions. Existing data from more than 1200 ears were used to analyze BCR as a function of Distortion Product Otoacoustic Emission (DPOAE) level. These data were selected because both audiometric and DPOAE data were available on every ear. Although these data were not obtained in newborns, this compromise was necessary because audiometric outcomes (especially in infants with congenital hearing loss) in neonates are either lacking or limited in number. As such, it is important to note that the characteristics of responses from the group of subjects that formed the bases of the present analyses are different from those for neonates. This limits the extent to which actual criterion levels can be selected but should not affect the general approach of using BCR as a framework for considering UNHS criteria. Estimates of the prevalence of congenital hearing loss identified through UNHS in 37 states and U.S. territories in 2004 were used to calculate BCR. A range of estimates for the lifetime monetary benefits and yearly costs for UNHS were used, based on data available in the literature. Still, exact benefits and costs are difficult to know. Both one-step (DPOAE alone) and two-step (DPOAE followed by automated auditory brainstem response, AABR) screening paradigms were considered in the calculation of BCR. The influence of middle ear effusion was simulated by incorporating a range of expected DPOAE level reductions into an additional BCR analyses Our calculations indicate that for a range of proposed benefit and cost estimates, the monetary benefits of both one-step (DPOAE alone) and two-step (DPOAE followed by AABR) NHS programs outweigh programmatic costs. Our calculations indicate that BCR is robust in that it can be applied regardless of the values that are assigned to benefit and cost. Maximum BCR was identified and remained stable regardless of these values; however, it was recognized that the use of maximum BCR could result in reduced test sensitivity and may not be optimal for use in UNHS programs. The inclusion of secondary AABR screening increases BCR but does not alter the DPOAE criterion level at which maximum BCR occurs. The model of middle ear effusion reduces overall DPOAE level, subsequently lowering the DPOAE criterion level at which maximum BCR was obtained BCR is one of several alternative methods for choosing UNHS criteria, in which the evaluation of costs and benefits allows clinical and societal considerations to be incorporated into the pass/refer decision in a meaningful way. Although some of the benefits of early identification of hearing impairment cannot be estimated through a monetary analysis, such as improved psychosocial development and quality of life, this article provides an alternative to audiologists and administrators for selecting UNHS protocols that includes consideration of societal implications of UNHS screening criteria. BCR suggests that UNHS is a worthwhile investment for society as benefits always outweigh costs, at least for the estimations included in this article. Although the use of screening criteria that maximize BCR results in lower test sensitivity compared with other criteria, BCR may be used to select criteria that result in increased test sensitivity and still provide a high, although not maximal, BCR. Using BCR analysis provides a framework in which the societal implications of NHS protocols are considered and emphasizes the value of UNHS.

Gene expression and mutation-guided synthetic lethality eradicates proliferating and quiescent leukemia cells

PubMed Central

Nieborowska-Skorska, Margaret; Sullivan, Katherine; Dasgupta, Yashodhara; Podszywalow-Bartnicka, Paulina; Maifrede, Silvia; Di Marcantonio, Daniela; Bolton-Gillespie, Elisabeth; Cramer-Morales, Kimberly; Lee, Jaewong; Li, Min; Slupianek, Artur; Gritsyuk, Daniel; Cerny-Reiterer, Sabine; Seferynska, Ilona; Bullinger, Lars; Gorbunova, Vera; Piwocka, Katarzyna; Valent, Peter; Civin, Curt I.; Muschen, Markus; Dick, John E.; Wang, Jean C.Y.; Bhatia, Smita; Bhatia, Ravi; Eppert, Kolja; Minden, Mark D.; Sykes, Stephen M.

2017-01-01

Quiescent and proliferating leukemia cells accumulate highly lethal DNA double-strand breaks that are repaired by 2 major mechanisms: BRCA-dependent homologous recombination and DNA-dependent protein kinase–mediated (DNA-PK–mediated) nonhomologous end-joining, whereas DNA repair pathways mediated by poly(ADP)ribose polymerase 1 (PARP1) serve as backups. Here we have designed a personalized medicine approach called gene expression and mutation analysis (GEMA) to identify BRCA- and DNA-PK–deficient leukemias either directly, using reverse transcription-quantitative PCR, microarrays, and flow cytometry, or indirectly, by the presence of oncogenes such as BCR-ABL1. DNA-PK–deficient quiescent leukemia cells and BRCA/DNA-PK–deficient proliferating leukemia cells were sensitive to PARP1 inhibitors that were administered alone or in combination with current antileukemic drugs. In conclusion, GEMA-guided targeting of PARP1 resulted in dual cellular synthetic lethality in quiescent and proliferating immature leukemia cells, and is thus a potential approach to eradicate leukemia stem and progenitor cells that are responsible for initiation and manifestation of the disease. Further, an analysis of The Cancer Genome Atlas database indicated that this personalized medicine approach could also be applied to treat numerous solid tumors from individual patients. PMID:28481221

Extracellular vesicle-mediated transfer of donor genomic DNA to recipient cells is a novel mechanism for genetic influence between cells

PubMed Central

Cai, Jin; Han, Yu; Ren, Hongmei; Chen, Caiyu; He, Duofen; Zhou, Lin; Eisner, Gilbert M.; Asico, Laureano D.; Jose, Pedro A.; Zeng, Chunyu

2013-01-01

Extracellular vesicles (EVs) carry signals within or at their limiting membranes, providing a mechanism by which cells can exchange more complex information than what was previously thought. In addition to mRNAs and microRNAs, there are DNA fragments in EVs. Solexa sequencing indicated the presence of at least 16434 genomic DNA (gDNA) fragments in the EVs from human plasma. Immunofluorescence study showed direct evidence that acridine orange-stained EV DNAs could be transferred into the cells and localize to and inside the nuclear membrane. However, whether the transferred EV DNAs are functional or not is not clear. We found that EV gDNAs could be homologously or heterologously transferred from donor cells to recipient cells, and increase gDNA-coding mRNA, protein expression, and function (e.g. AT1 receptor). An endogenous promoter of the AT1 receptor, NF-κB, could be recruited to the transferred DNAs in the nucleus, and increase the transcription of AT1 receptor in the recipient cells. Moreover, the transferred EV gDNAs have pathophysiological significance. BCR/ABL hybrid gene, involved in the pathogenesis of chronic myeloid leukemia, could be transferred from K562 EVs to HEK293 cells or neutrophils. Our present study shows that the gDNAs transferred from EVs to cells have physiological significance, not only to increase the gDNA-coding mRNA and protein levels, but also to influence function in recipient cells. PMID:23580760

B cell Toll-like receptors and immunoglobulin class-switch DNA recombination

PubMed Central

Pone, Egest J.; Xu, Zhenming; White, Clayton A.; Zan, Hong; Casali, Paolo

2014-01-01

Toll-like receptors (TLRs) are a family of conserved pattern recognition receptors (PRRs). Engagement of TLRs in B cells by microbe-associated molecular patterns (MAMPs) induces T-independent (TI) antibody responses and plays an important role in the early stages of T-dependent (TD) antibody responses before specific T cell help becomes available, in part by facilitating B cell entry into the germinal center reaction. The role of B cell TLRs in the antibody response is magnified by the synergy of B cell receptor (BCR) crosslinking and TLR engagement in promoting B cell proliferation and efficiently inducing immunoglobulin (Ig) class switch DNA recombination (CSR), which crucially diversifies the antibody biological effector functions. Dual engagement of TLRs and BCR can be mediated by complex MAMPs such as lipopolysaccharides (LPS), which engages TLR4 through its lipid A moiety and crosslinks the BCR through its polysaccharidic moiety (O-antigen). Dual BCR/TLR engagement induces CSR to all Ig isotypes, as directed by different cytokines, while engagement of any TLR alone induces only marginal CSR. Integration of BCR and TLR signaling results in activation of the canonical and non-canonical NF-κB pathways, induction of activation-induced cytidine deaminase (AID) and germline transcription of switch (S) regions in the IgH locus. The last two are essential events for CSR to unfold. A critical role of dual BCR/TLR engagement in induction of CSR and generation of neutralizing antibodies is emphasized by the emergence of TLR ligands as integral components of vaccines that greatly boost humoral immunity in a B cell-intrinsic fashion. Further, dual BCR/TLR engagement by complex self-antigens will result in dysregulation of AID expression and CSR in autoreactive B cells, leading to generation of isotype-switched pathogenic autoantibodies. Finally, an important aspect of dual BCR/TLR engagement is the boosting of specific antibody response to tumor antigens, as suggested by high titers of anti-tumor antibodies in response to tumor vaccines that contain TLR agonists. PMID:22652800

Pretreatment evaluation of fluorescence resonance energy transfer-based drug sensitivity test for patients with chronic myelogenous leukemia treated with dasatinib.

PubMed

Kondo, Takeshi; Fujioka, Mari; Tsuda, Masumi; Murai, Kazunori; Yamaguchi, Kohei; Miyagishima, Takuto; Shindo, Motohiro; Nagashima, Takahiro; Wakasa, Kentaro; Fujimoto, Nozomu; Yamamoto, Satoshi; Yonezumi, Masakatsu; Saito, Souichi; Sato, Shinji; Ogawa, Kazuei; Chou, Takaaki; Watanabe, Reiko; Kato, Yuichi; Takahashi, Shuichiro; Okano, Yoshiaki; Yamamoto, Joji; Ohta, Masatsugu; Iijima, Hiroaki; Oba, Koji; Kishino, Satoshi; Sakamoto, Junichi; Ishida, Yoji; Ohba, Yusuke; Teshima, Takanori

2018-05-02

Tyrosine kinase inhibitors (TKI) are used for primary therapy in patients with newly diagnosed CML. However, a reliable method for optimal selection of a TKI from the viewpoint of drug sensitivity of CML cells has not been established. We have developed a FRET-based drug sensitivity test in which a CrkL-derived fluorescent biosensor efficiently quantifies the kinase activity of BCR-ABL of living cells and sensitively evaluates the inhibitory activity of a TKI against BCR-ABL. Here, we validated the utility of the FRET-based drug sensitivity test carried out at diagnosis for predicting the molecular efficacy. Sixty-two patients with newly diagnosed chronic phase CML were enrolled in this study and treated with dasatinib. Bone marrow cells at diagnosis were subjected to FRET analysis. The ΔFRET value was calculated by subtraction of FRET efficiency in the presence of dasatinib from that in the absence of dasatinib. Treatment response was evaluated every 3 months by the BCR-ABL1 International Scale. Based on the ΔFRET value and molecular response, a threshold of the ΔFRET value in the top 10% of FRET efficiency was set to 0.31. Patients with ΔFRET value ≥0.31 had significantly superior molecular responses (MMR at 6 and 9 months and both MR4 and MR4.5 at 6, 9, and 12 months) compared with the responses in patients with ΔFRET value <0.31. These results suggest that the FRET-based drug sensitivity test at diagnosis can predict early and deep molecular responses. This study is registered with UMIN Clinical Trials Registry (UMIN000006358). © 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

IMATINIB 800MG DAILY INDUCES DEEPER MOLECULAR RESPONSES THAN IMATINIB 400MG DAILY: RESULTS OF SWOG S0325, AN INTERGROUP RANDOMIZED PHASE II TRIAL IN NEWLY DIAGNOSED CHRONIC PHASE CHRONIC MYELOID LEUKAEMIA

PubMed Central

Deininger, Michael W.; Kopecky, Kenneth J.; Radich, Jerald P.; Kamel-Reid, Suzanne; Stock, Wendy; Paietta, Elisabeth; Emanuel, Peter D.; Tallman, Martin; Wadleigh, Martha; Larson, Richard A.; Lipton, Jeffrey H.; Slovak, Marilyn L.; Appelbaum, Frederick R.; Druker, Brian J.

2014-01-01

The standard dose of imatinib for newly diagnosed patients with chronic phase chronic myeloid leukemia (CP-CML) is 400mg daily (IM400), but the optimal dose is unknown. This randomized phase II study compared the rates of molecular, haematologic and cytogenetic response to IM400 vs. imatinib 400mg twice daily (IM800) in 153 adult patients with CP-CML. Dose adjustments for toxicity were flexible to maximize retention on study. Molecular response (MR) at 12 months was deeper in the IM800 arm (4-log reduction of BCR-ABL1 mRNA: 25% vs. 10% of patients, P=0.038; 3-log reduction: 53% vs. 35%, P=0.049). During the first 12 months BCR-ABL1 levels in the IM800 arm were an average 2.9-fold lower than in the IM400 arm (P=0.010). Complete haematologic response was similar, but complete cytogenetic response was higher with IM800 (85% vs. 67%, P=0.040). Grade 3–4 toxicities were more common for IM800 (58% vs. 31%, P=0.0007), and were most commonly haematologic. Few patients have relapsed, progressed or died, but progression-free (P=0.048) and relapse-free (P=0.031) survival were superior for IM800. In newly diagnosed CP-CML patients, IM800 induced deeper molecular responses than IM400, with a trend for improved progression-free and overall survival, but was associated with more severe toxicity. PMID:24383843

Imatinib mesylate in chronic myeloid leukemia: frontline treatment and long-term outcomes.

PubMed

Stagno, Fabio; Stella, Stefania; Spitaleri, Antonio; Pennisi, Maria Stella; Di Raimondo, Francesco; Vigneri, Paolo

2016-01-01

The tyrosine kinase inhibitor Imatinib Mesylate has dramatically improved the clinical outcome of chronic myeloid leukemia (CML) patients in the chronic phase of the disease, generating unprecedented rates of complete hematologic and cytogenetic responses and sustained reductions in BCR-ABL transcripts. Here, we present an overview on the efficacy and safety of Imatinib and describe the most important clinical studies employing this drug for the frontline treatment of chronic phase CML. We also discuss recent reports describing the long-term outcome of patients receiving Imatinib for their disease. The imminent availability of generic forms of Imatinib coupled with the approval of expensive second-generation tyrosine kinase inhibitors underlines an unmet need for early molecular parameters that may distinguish CML patients likely to benefit from the drug from those that should receive alternative forms of treatment.

Bilineal Extramedullary Blast Crisis as an Initial Presentation of Chronic Myeloid Leukemia: A Case Report and Literature Review

PubMed Central

Gao, Xiaoning; Li, Jie; Wang, Lili; Lin, Ji; Jin, Hongshi; Xu, Yihan; Wang, Nan; Zhao, Yu; Liu, Daihong; Yu, Li; Wang, Quanshun

2016-01-01

Patient: Male, 49 Final Diagnosis: T-lymphoid/myeloid bilineal blastic transformation of CML Symptoms: Rapidly enlarging mass in left neck Medication: — Clinical Procedure: Biopsy of the left submandibular lymph nodes Specialty: Hematology Objective: Rare co-existance of disease or pathology Background: Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder characterized by the Philadelphia chromosome generated by the reciprocal translocation t(9: 22)(q34;q11). CML is usually diagnosed in the chronic phase. Blast crisis represents an advanced phase of CML. Extramedullary blast crisis as the initial presentation of CML with bone marrow remaining in chronic phase is an unusual event. Further, extramedullary blast crisis with T lymphoid/myeloid bilineal phenotype as an initial presentation for CML is extremely unusual. Case Report: Here, we report the case of a 49-year-old male with rapidly enlarged submandibular lymph nodes. Biopsy specimen from the nodes revealed a characteristic appearance with morphologically and immunohistochemically distinct myeloblasts and T lymphoblasts co-localized in 2 adjacent regions, accompanied by chronic phase of the disease in bone marrow. The presence of the BCR/ABL1 fusion gene within both cellular populations in this case confirmed the extramedullary disease represented a localized T lymphoid/myeloid bilineal blastic transformation of CML. After 3 courses of combined chemotherapy plus tyrosine kinase inhibitor treatment, the mass was completely regressed with a 3-log decrease in BCR/ABL1 transcript from baseline. Five months after the diagnosis, the patient showed diminished vision, hand tremors, and weakness of lower extremities. Flow cytometric immunophenotyping of cerebrospinal fluid revealed the presence of myeloid blasts. An isolated central nervous system relapse of leukemia was identified. Following high-dose systemic and intrathecal chemotherapy, the patient continued to do well. Conclusions: The possibility of extramedullary blast crisis as an initial presentation in patients with CML should be considered. Further, an isolated central nervous system blast crisis should be considered if neurological symptoms evolve in patients who have shown a good response to therapy. PMID:27784881

Ibrutinib inhibits pre-BCR+ B-cell acute lymphoblastic leukemia progression by targeting BTK and BLK.

PubMed

Kim, Ekaterina; Hurtz, Christian; Koehrer, Stefan; Wang, Zhiqiang; Balasubramanian, Sriram; Chang, Betty Y; Müschen, Markus; Davis, R Eric; Burger, Jan A

2017-03-02

Targeting B-cell receptor (BCR) signaling is a successful therapeutic strategy in mature B-cell malignancies. Precursor BCR (pre-BCR) signaling, which is critical during normal B lymphopoiesis, also plays an important role in pre-BCR + B cell acute lymphoblastic leukemia (B-ALL). Here, we investigated the activity and mechanism of action of the BTK inhibitor ibrutinib in preclinical models of B-ALL. Pre-BCR + ALL cells were exquisitely sensitive to ibrutinib at therapeutically relevant drug concentrations. In pre-BCR + ALL, ibrutinib thwarted autonomous and induced pre-BCR signaling, resulting in deactivation of PI3K/Akt signaling. Ibrutinib modulated the expression of pre-BCR regulators (PTPN6, CD22, CD72, and PKCβ) and substantially reduced BCL6 levels. Ibrutinib inhibited ALL cell migration toward CXCL12 and beneath marrow stromal cells and reduced CD44 expression. CRISPR-Cas9 gene editing revealed that both BTK and B lymphocyte kinase (BLK) are relevant targets of ibrutinib in pre-BCR + ALL. Consequently, in mouse xenograft models of pre-BCR + ALL, ibrutinib treatment significantly prolonged survival. Combination treatment of ibrutinib with dexamethasone or vincristine demonstrated synergistic activity against pre-BCR + ALL. These data corroborate ibrutinib as a promising targeted agent for pre-BCR + ALL and highlight the importance of ibrutinib effects on alternative kinase targets. © 2017 by The American Society of Hematology.

PAX5 mutations occur frequently in adult B-cell progenitor acute lymphoblastic leukemia and PAX5 haploinsufficiency is associated with BCR-ABL1 and TCF3-PBX1 fusion genes: a GRAALL study.

PubMed

Familiades, J; Bousquet, M; Lafage-Pochitaloff, M; Béné, M-C; Beldjord, K; De Vos, J; Dastugue, N; Coyaud, E; Struski, S; Quelen, C; Prade-Houdellier, N; Dobbelstein, S; Cayuela, J-M; Soulier, J; Grardel, N; Preudhomme, C; Cavé, H; Blanchet, O; Lhéritier, V; Delannoy, A; Chalandon, Y; Ifrah, N; Pigneux, A; Brousset, P; Macintyre, E A; Huguet, F; Dombret, H; Broccardo, C; Delabesse, E

2009-11-01

Adult and child B-cell progenitor acute lymphoblastic leukemia (BCP-ALL) differ in terms of incidence and prognosis. These disparities are mainly due to the molecular abnormalities associated with these two clinical entities. A genome-wide analysis using oligo SNP arrays recently demonstrated that PAX5 (paired-box domain 5) is the main target of somatic mutations in childhood BCP-ALL being altered in 38.9% of the cases. We report here the most extensive analysis of alterations of PAX5 coding sequence in 117 adult BCP-ALL patients in the unique clinical protocol GRAALL-2003/GRAAPH-2003. Our study demonstrates that PAX5 is mutated in 34% of adult BCP-ALL, mutations being partial or complete deletion, partial or complete amplification, point mutation or fusion gene. PAX5 alterations are heterogeneous consisting in complete loss in 17%, focal deletions in 10%, point mutations in 7% and translocations in 1% of the cases. PAX5 complete loss and PAX5 point mutations differ. PAX5 complete loss seems to be a secondary event and is significantly associated with BCR-ABL1 or TCF3-PBX1 fusion genes and a lower white blood cell count.

Sodium selenite increases the transcript levels of iodothyronine deiodinases I and II in ovine and bovine fetal thyrocytes in vitro.

PubMed

Foroughi, Mohammad Ali; Dehghani, Hesam; Mahdavi-Shahri, Naser; Bassami, Mohammad Reza

2013-07-01

Selenium is essential for thyroid hormone homeostasis. Selenium is co-translationally incorporated into the protein backbone of 5' deiodinase enzymes, which are responsible for the intra- and extra-thyroidal activation of thyroid hormones. The objective of this study was to evaluate the effects of sodium selenite on the transcript levels of type I (DIO1) and II (DIO2) deiodinases in the primary culture of ovine and bovine fetal thyroid. By culture of fetal thyrocytes in the presence or absence of sodium selenite, and quantification of DIO1 and DIO2 transcripts using real-time reverse transcription polymerase chain reaction (RT-qPCR), we found that sodium selenite is able to increase the abundance of transcripts for DIO1 and DIO2 genes. We also found that cultured thyrocytes in the presence of sodium selenite compared to control cultured thyrocytes release more T3 into the culture medium. This indicates that in the presence of sodium selenite higher levels of DIO1 and DIO2 enzymes are produced, which are able to convert T4 to T3. In conclusion, we have shown that sodium selenite is increasing the abundance of DIO1 and DIO2 transcripts and increasing the production and release of T3 from cultured fetal thyrocytes. This finding emphasizes the role of selenium in transcriptional and expression processes during development and suggests that selenium deficiency during pregnancy in sheep and cattle may lead to the lower levels of DIO1 and DIO2 transcription in fetal thyroid, and thus, lower level of thyroidal T3 release into the fetal serum. Copyright © 2013 Elsevier GmbH. All rights reserved.

How I determine if and when to recommend stopping tyrosine kinase inhibitor treatment for chronic myeloid leukaemia.

PubMed

Ross, David M; Hughes, Timothy P

2014-07-01

Treatment-free remission (TFR) has recently emerged as a goal of treatment in chronic myeloid leukaemia (CML). Molecular remission is sustained in around 30% of imatinib-treated patients who stop treatment after ≥2 years with undetectable minimal residual disease (UMRD) by conventional real-time reverse transcription polymerase chain reaction. An additional 20-30% of patients will lose UMRD, but remain in stable major molecular remission off treatment. Most patients with molecular recurrence have a significant increase in BCR-ABL1 within the first 6 months off treatment, but there are also rare late relapses. As re-treatment with imatinib restores control, a trial of TFR is safe so long as careful molecular monitoring is provided to enable prompt re-treatment. The minimum eligibility criteria for a trial of TFR are not yet defined, but the available data support a MRD level of around a molecular response of 4.5 log for at least 2 years. Factors associated with a higher probability of TFR include low risk Sokal score, prior interferon treatment, longer total duration of imatinib treatment and higher numbers of natural killer cells at the time of imatinib discontinuation. Preliminary data suggest that the rate of TFR in patients treated with more potent tyrosine kinase inhibitors will probably be higher. The biology that underlies TFR is an area of active investigation. © 2014 John Wiley & Sons Ltd.

Myeloproliferative Neoplasms (MPNs) Patient Registry

ClinicalTrials.gov

2017-10-27

Primary Myelofibrosis; Polycythemia Vera; Essential Thrombocythemia; Mastocytosis; Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative; Leukemia, Myelomonocytic, Juvenile; Chronic Eosinophilic Leukemia-not Otherwise Specified; Myelodysplastic-Myeloproliferative Diseases; Neoplasms; Leukemia, Myelomonocytic, Chronic

Epigenetic repression of the Igk locus by STAT5-mediated Ezh2 recruitment

PubMed Central

Mandal, Malay; Powers, Sarah E.; Maienschein-Cline, Mark; Bartom, Elizabeth T.; Hamel, Keith M.; Kee, Barbara L.; Dinner, Aaron R.; Clark, Marcus R.

2011-01-01

During B lymphopoiesis, Igk recombination requires pre-B cell receptor (pre-BCR) expression and escape from interleukin 7 receptor (IL-7R) signaling. By activating the transcription factor STAT5, IL-7R signaling maintains proliferation and represses Igk germline transcription by unknown mechanisms. We demonstrate that STAT5 tetramer bound the Igk intronic enhancer (Eκi), leading to recruitment of the histone methyltransferase Ezh2. Ezh2 marked H3K27me3 throughout Jκ to Cκ. In the absence of Ezh2, IL-7 failed to repress Igk germline transcription. H3K27me3 modifications were lost after termination of IL-7R–STAT5 signaling and E2A bound Eκi, resulting in acquisition of H3K4me1 and H4Ac. Genome-wide analyses revealed a STAT5 tetrameric binding motif associated with transcriptional repression. These data demonstrate how IL-7R signaling represses Igk germline transcription and provide a general model for STAT5-mediated epigenetic transcriptional repression. PMID:22037603

Race and risk of metastases and survival after radical prostatectomy: Results from the SEARCH database.

PubMed

Freedland, Stephen J; Vidal, Adriana C; Howard, Lauren E; Terris, Martha K; Cooperberg, Matthew R; Amling, Christopher L; Kane, Christopher J; Aronson, William J

2017-11-01

Black race is associated with prostate cancer (PC) diagnosis and poor outcome. Previously, the authors reported that black men undergoing radical prostatectomy (RP) in equal-access hospitals had an increased risk of biochemical disease recurrence (BCR), but recurrences were equally aggressive as those occurring in white men. The authors examined the association between race and long-term outcomes after RP. Data regarding 1665 black men (37%) and 2791 white men (63%) undergoing RP were analyzed. Using Cox models, the authors tested the association between race and BCR, BCR with a prostate-specific antigen (PSA) doubling time <9 months (aggressive disease recurrence), metastases, PC-specific death, and overall death. At a median follow-up of 102 months, 1566 men (35%) developed BCR, 217 men (5%) experienced aggressive disease recurrence, 193 men (4%) developed metastases, and 1207 men (27%) had died, 107 of whom (2%) died of PC. White men were older and had a lower preoperative PSA level, a lower biopsy and pathological grade group, and more capsular penetration but less seminal vesicle invasion and positive surgical margins versus black men (all P<.05). Black men were found to have a more recent surgery year (P<.001). On univariable analysis, black race was associated with increased BCR (P = .003) and reduced overall death (P = .017). On multivariable analysis, black race was not found to be associated with BCR (hazard ratio [HR], 1.07; P = .26), aggressive recurrence (HR, 1.14; P = .42), metastasis (HR, 1.24; P = .21), PC-specific death (HR, 1.03; P = .91), or overall death (HR, 1.03; P = .67). Among men undergoing RP at equal-access centers, although black men were found to have an increased risk of BCR, they had similar risks of aggressive disease recurrence, metastasis, and PC-specific death compared with white men, and the risk of BCR was found to be similar after controlling for risk parameters. Longer follow-up is needed to confirm these findings. Cancer 2017;123:4199-4206. © 2017 American Cancer Society. © 2017 American Cancer Society.

Tumor suppressor function of PGP9.5 is associated with epigenetic regulation in prostate cancer--novel predictor of biochemical recurrence after radical surgery.

PubMed

Mitsui, Yozo; Shiina, Hiroaki; Hiraki, Miho; Arichi, Naoko; Hiraoka, Takeo; Sumura, Masahiro; Honda, Satoshi; Yasumoto, Hiroaki; Igawa, Mikio

2012-03-01

The expression level of protein G product 9.5 (PGP9.5) is downregulated because of promoter CpG hypermethylation in several tumors. We speculated that impaired regulation of PGP9.5 through epigenetic pathways is associated with the pathogenesis of prostate cancer. CpG methylation of the PGP9.5 gene was analyzed in cultured prostate cancer cell lines, 226 localized prostate cancer samples from radical prostatectomy cases, and 80 benign prostate hyperplasia (BPH) tissues. Following 5-aza-2'-deoxycytidune treatment, increased PGP9.5 mRNA transcript expression was found in the LNCaP and PC3 cell lines. With bisulfite DNA sequencing, partial methylation of the PGP9.5 promoter was shown in LNCaP whereas complete methylation was found in PC3 cells. After transfection of PGP9.5 siRNA, cell viability was significantly accelerated in LNCaP but not in PC3 cells as compared with control siRNA transfection. Promoter methylation of PGP9.5 was extremely low in only one of 80 BPH tissues, whereas it was found in 37 of 226 prostate cancer tissues. Expression of the mRNA transcript of PGP9.5 was significantly lower in methylation (+) than methylation (-) prostate cancer tissues. Multivariate analysis of biochemical recurrence (BCR) after an radical prostatectomy revealed pT category and PGP9.5 methylation as prognostically relevant. Further stratification with the pT category in addition to methylation status identified a stepwise reduction of BCR-free probability. This is the first clinical and comprehensive study of inactivation of the PGP9.5 gene via epigenetic pathways in primary prostate cancer. CpG methylation of PGP9.5 in primary prostate cancer might become useful as a molecular marker for early clinical prediction of BCR after radical prostatectomy. ©2012 AACR.

Dasatinib in Treating Young Patients With Recurrent or Refractory Solid Tumors or Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia or Chronic Myelogenous Leukemia That Did Not Respond to Imatinib Mesylate

ClinicalTrials.gov

2013-02-04

Accelerated Phase Chronic Myelogenous Leukemia; Blastic Phase Chronic Myelogenous Leukemia; Childhood Chronic Myelogenous Leukemia; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Meningeal Chronic Myelogenous Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Relapsing Chronic Myelogenous Leukemia; Unspecified Childhood Solid Tumor, Protocol Specific

Visualization of proteolytic activity associated with the apoptotic response in cancer cells

NASA Astrophysics Data System (ADS)

Tice, Brian George

Caspases execute programmed cell death, where low levels of caspase activity are linked to cancer. Chemotherapies utilize induction of apoptosis as a key mechanism for cancer treatment, where caspase-3 is a major player involved in dismantling these aberrant cells. The ability to sensitively measure the initial caspase-3 cleavage events during apoptosis is important for understanding the initiation of this complex cellular process, however, current ensemble methods are not sensitive enough to measure single cleavage events in cells. By utilizing the optical properties of plasmon coupling, peptide-linked gold nanoparticles were developed to enable single molecule imaging of caspase-3 activity in two different cancer systems. Au crown nanoparticles were assembled in a multimeric fashion to overcome the high and heterogeneous background scattering of live cells. In a colon cancer (SW620) cell line challenged with tumor necrosis factor-alpha (TNF-alpha), single molecule trajectories show early stage caspase-3 activation within minutes, which was not detectable by ensemble assays until 23 hours. Variability in caspase-3 activation among the population of cells was identified and likely a result of each cell's specific resistance to death receptor-induced apoptosis. Following these studies, improvements by way of sensitivity and selectivity were tailored into an improved nanosensor construct. Au nanoshell dimers were prepared as a comparably bright construct with 1) reduced heterogeneity compared to the synthesis of the crown nanoparticles and 2) a peptide sequence highly selective for caspase-3. Chronic myeloid leukemia (CML) K562 cells were assessed for their early apoptotic response upon treatment with dasatinib, a clinically approved tyrosine kinase inhibitor that specifically targets BCR-ABL. It has been demonstrated that inhibition of BCR-ABL by dasatinib commits K562 cells to apoptosis. Single molecule experiments with Au nanoshell dimers show caspase-3 activation as early as 8 hours than previously reported. This suggests an early commitment to apoptosis that precedes the competing fate of growth factor mediated survival in CML patient-derived BCR-ABL cells. These nanosensors are sensitive and selective in observing caspase-3 activation compared to ensemble methods; and allow the possibility to detect caspase-3 activity for use as a drug screening or diagnostic tool for personalized care in the treatment of cancer.

The SH2 Domain Regulates c-Abl Kinase Activation by a Cyclin-Like Mechanism and Remodulation of the Hinge Motion

PubMed Central

Dölker, Nicole; Górna, Maria W.; Sutto, Ludovico; Torralba, Antonio S.; Superti-Furga, Giulio; Gervasio, Francesco L.

2014-01-01

Regulation of the c-Abl (ABL1) tyrosine kinase is important because of its role in cellular signaling, and its relevance in the leukemiogenic counterpart (BCR-ABL). Both auto-inhibition and full activation of c-Abl are regulated by the interaction of the catalytic domain with the Src Homology 2 (SH2) domain. The mechanism by which this interaction enhances catalysis is not known. We combined computational simulations with mutagenesis and functional analysis to find that the SH2 domain conveys both local and global effects on the dynamics of the catalytic domain. Locally, it regulates the flexibility of the αC helix in a fashion reminiscent of cyclins in cyclin-dependent kinases, reorienting catalytically important motifs. At a more global level, SH2 binding redirects the hinge motion of the N and C lobes and changes the conformational equilibrium of the activation loop. The complex network of subtle structural shifts that link the SH2 domain with the activation loop and the active site may be partially conserved with other SH2-domain containing kinases and therefore offer additional parameters for the design of conformation-specific inhibitors. PMID:25299346

The SH2 domain regulates c-Abl kinase activation by a cyclin-like mechanism and remodulation of the hinge motion.

PubMed

Dölker, Nicole; Górna, Maria W; Sutto, Ludovico; Torralba, Antonio S; Superti-Furga, Giulio; Gervasio, Francesco L

2014-10-01

Regulation of the c-Abl (ABL1) tyrosine kinase is important because of its role in cellular signaling, and its relevance in the leukemiogenic counterpart (BCR-ABL). Both auto-inhibition and full activation of c-Abl are regulated by the interaction of the catalytic domain with the Src Homology 2 (SH2) domain. The mechanism by which this interaction enhances catalysis is not known. We combined computational simulations with mutagenesis and functional analysis to find that the SH2 domain conveys both local and global effects on the dynamics of the catalytic domain. Locally, it regulates the flexibility of the αC helix in a fashion reminiscent of cyclins in cyclin-dependent kinases, reorienting catalytically important motifs. At a more global level, SH2 binding redirects the hinge motion of the N and C lobes and changes the conformational equilibrium of the activation loop. The complex network of subtle structural shifts that link the SH2 domain with the activation loop and the active site may be partially conserved with other SH2-domain containing kinases and therefore offer additional parameters for the design of conformation-specific inhibitors.

The oncoprotein HBXIP upregulates PDGFB via activating transcription factor Sp1 to promote the proliferation of breast cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yingyi; Zhao, Yu; Li, Leilei

2013-05-03

Highlights: •HBXIP is able to upregulate the expression of PDGFB in breast cancer cells. •HBXIP serves as a coactivator of activating transcription factor Sp1. •HBXIP stimulates the PDGFB promoter via activating transcription factor Sp1. •HBXIP promotes the proliferation of breast cancer cell via upregulating PDGFB. -- Abstract: We have reported that the oncoprotein hepatitis B virus X-interacting protein (HBXIP) acts as a novel transcriptional coactivator to promote proliferation and migration of breast cancer cells. Previously, we showed that HBXIP was able to activate nuclear factor-κB (NF-κB) in breast cancer cells. As an oncogene, the platelet-derived growth factor beta polypeptide (PDGFB)more » plays crucial roles in carcinogenesis. In the present study, we found that both HBXIP and PDGFB were highly expressed in breast cancer cell lines. Interestingly, HBXIP was able to increase transcriptional activity of NF-κB through PDGFB, suggesting that HBXIP is associated with PDGFB in the cells. Moreover, HBXIP was able to upregulate PDGFB at the levels of mRNA, protein and promoter in the cells. Then, we identified that HBXIP stimulated the promoter of PDGFB through activating transcription factor Sp1. In function, HBXIP enhanced the proliferation of breast cancer cells through PDGFB in vitro. Thus, we conclude that HBXIP upregulates PDGFB via activating transcription factor Sp1 to promote proliferation of breast cancer cells.« less

Assessing the Optimal Timing for Early Salvage Radiation Therapy in Patients with Prostate-specific Antigen Rise After Radical Prostatectomy.

PubMed

Fossati, Nicola; Karnes, R Jeffrey; Cozzarini, Cesare; Fiorino, Claudio; Gandaglia, Giorgio; Joniau, Steven; Boorjian, Stephen A; Goldner, Gregor; Hinkelbein, Wolfgang; Haustermans, Karin; Tombal, Bertrand; Shariat, Shahrokh; Karakiewicz, Pierre I; Montorsi, Francesco; Van Poppel, Hein; Wiegel, Thomas; Briganti, Alberto

2016-04-01

Early salvage radiation therapy (eSRT) represents a treatment option for patients who experience a prostate-specific antigen (PSA) rise after radical prostatectomy (RP); however, the optimal PSA level for eSRT administration is still unclear. To test the impact of PSA level on cancer control after eSRT according to pathologic tumour characteristics. The study included 716 node-negative patients with undetectable postoperative PSA who experienced a PSA rise after RP. All patients received eSRT, defined as local radiation to the prostate and seminal vesicle bed, delivered at PSA ≤ 0.5 ng/ml. Biochemical recurrence (BCR) after eSRT was defined as two consecutive PSA values ≥ 0.2 ng/ml. Multivariable Cox regression analysis tested the association between pre-eSRT PSA level and BCR after eSRT. Covariates consisted of pathologic stage (pT2 vs pT3a vs pT3b or higher), pathologic Gleason score (≤ 6, 7, or ≥ 8), and surgical margin status (negative vs positive). We tested an interaction with PSA level and baseline pathologic risk for the hypothesis that BCR-free survival differed by pre-eSRT PSA level. Three pathologic risk factors were identified: pathologic stage pT3b or higher, pathologic Gleason score ≥ 8, and negative surgical margins. Median follow-up among patients who did not experience BCR after eSRT was 57 mo (interquartile range: 27-105). At 5 yr after eSRT, BCR-free survival rate was 82% (95% confidence interval [CI], 78-85). At multivariable Cox regression analysis, pre-eSRT PSA level was significantly associated with BCR after eSRT (hazard ratio: 4.89; 95% CI, 1.40-22.9; p < 0.0001). When patients were stratified according to the number of risk factors at final pathology, patients with at least two pathologic risk factors showed an increased risk of 5-yr BCR as high as 10% per 0.1 ng/ml of PSA level compared with only 1.5% in patients with one or no pathologic risk factors. In this retrospective study, cancer control after eSRT greatly depended on pretreatment PSA. The absolute PSA level had a different prognostic value depending on the pathologic characteristics of the tumour. In patients with more adverse pathologic features, eSRT conferred better cancer control when administered at the very first sign of PSA rise. Conversely, the benefit of eSRT was less evident in men with favourable disease at RP. In this retrospective study, cancer control after early salvage radiation therapy (eSRT) was influenced by pretreatment prostate-specific antigen (PSA) level. This effect was highest in men with at least two of the following pathologic features: pT3b/pT4 disease, pathologic Gleason score ≥ 8, and negative surgical margins. In these patients, eSRT conferred better cancer control when administered at the very first sign of PSA rise. Copyright © 2015 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Quantitative Analysis of Mutant Subclones in Chronic Myeloid Leukemia: Comparison of Different Methodological Approaches

PubMed Central

Preuner, Sandra; Barna, Agnes; Frommlet, Florian; Czurda, Stefan; Konstantin, Byrgazov; Alikian, Mary; Machova Polakova, Katerina; Sacha, Tomasz; Richter, Johan; Lion, Thomas; Gabriel, Christian

2016-01-01

Identification and quantitative monitoring of mutant BCR-ABL1 subclones displaying resistance to tyrosine kinase inhibitors (TKIs) have become important tasks in patients with Ph-positive leukemias. Different technologies have been established for patient screening. Various next-generation sequencing (NGS) platforms facilitating sensitive detection and quantitative monitoring of mutations in the ABL1-kinase domain (KD) have been introduced recently, and are expected to become the preferred technology in the future. However, broad clinical implementation of NGS methods has been hampered by the limited accessibility at different centers and the current costs of analysis which may not be regarded as readily affordable for routine diagnostic monitoring. It is therefore of interest to determine whether NGS platforms can be adequately substituted by other methodological approaches. We have tested three different techniques including pyrosequencing, LD (ligation-dependent)-PCR and NGS in a series of peripheral blood specimens from chronic myeloid leukemia (CML) patients carrying single or multiple mutations in the BCR-ABL1 KD. The proliferation kinetics of mutant subclones in serial specimens obtained during the course of TKI-treatment revealed similar profiles via all technical approaches, but individual specimens showed statistically significant differences between NGS and the other methods tested. The observations indicate that different approaches to detection and quantification of mutant subclones may be applicable for the monitoring of clonal kinetics, but careful calibration of each method is required for accurate size assessment of mutant subclones at individual time points. PMID:27136541

Quantitative Analysis of Mutant Subclones in Chronic Myeloid Leukemia: Comparison of Different Methodological Approaches.

PubMed

Preuner, Sandra; Barna, Agnes; Frommlet, Florian; Czurda, Stefan; Konstantin, Byrgazov; Alikian, Mary; Machova Polakova, Katerina; Sacha, Tomasz; Richter, Johan; Lion, Thomas; Gabriel, Christian

2016-04-29

Identification and quantitative monitoring of mutant BCR-ABL1 subclones displaying resistance to tyrosine kinase inhibitors (TKIs) have become important tasks in patients with Ph-positive leukemias. Different technologies have been established for patient screening. Various next-generation sequencing (NGS) platforms facilitating sensitive detection and quantitative monitoring of mutations in the ABL1-kinase domain (KD) have been introduced recently, and are expected to become the preferred technology in the future. However, broad clinical implementation of NGS methods has been hampered by the limited accessibility at different centers and the current costs of analysis which may not be regarded as readily affordable for routine diagnostic monitoring. It is therefore of interest to determine whether NGS platforms can be adequately substituted by other methodological approaches. We have tested three different techniques including pyrosequencing, LD (ligation-dependent)-PCR and NGS in a series of peripheral blood specimens from chronic myeloid leukemia (CML) patients carrying single or multiple mutations in the BCR-ABL1 KD. The proliferation kinetics of mutant subclones in serial specimens obtained during the course of TKI-treatment revealed similar profiles via all technical approaches, but individual specimens showed statistically significant differences between NGS and the other methods tested. The observations indicate that different approaches to detection and quantification of mutant subclones may be applicable for the monitoring of clonal kinetics, but careful calibration of each method is required for accurate size assessment of mutant subclones at individual time points.

Chronic Myeloid Leukemia

MedlinePlus

... medication. Protein Synthesis Inhibitor Therapy. Omacetaxine (Synribo®) a non-TKI, chemotherapy drug, is approved for chronic and ... as BCR-ABL 10%. This reduction is approximately equivalent to a major cytogenetic response. {{ A 2-log ...

Regulation of HtrA2 on WT1 gene expression under imatinib stimulation and its effects on the cell biology of K562 cells.

PubMed

Zhang, Lixia; Li, Yan; Li, Xiaoyan; Zhang, Qing; Qiu, Shaowei; Zhang, Qi; Wang, Min; Xing, Haiyan; Rao, Qing; Tian, Zheng; Tang, Kejing; Wang, Jianxiang; Mi, Yingchang

2017-09-01

The aim of the present study was to investigate the regulation of Wilms Tumor 1 (WT1) by serine protease high-temperature requirement protein A2 (HtrA2), a member of the Htr family, in K562 cells. In addition, the study aimed to observe the effect of this regulation on cell biological functions and its associated mechanisms. Expression of WT1 and HtrA2 mRNA, and proteins following imatinib and the HtrA2 inhibitor 5-[5-(2-nitrophenyl) furfuryl iodine]-1, 3-diphenyl-2-thiobarbituric acid (UCF-101) treatment was detected with reverse transcription-quantitative polymerase chain reaction and western blot analysis. Subsequent to treatment with drugs and UCF-101, the proliferative function of K562 cells was detected using MTT assays, and the rate of apoptosis was detected using Annexin V with propidium iodide flow cytometry in K562 cells. The protein levels in the signaling pathway were analyzed using western blotting following treatment with imatinib and UCF-101. In K562 cells, imatinib treatment activated HtrA2 gene at a transcription level, while the WT1 gene was simultaneously downregulated. Following HtrA2 inhibitor (UCF-101) treatment, the downregulation of WT1 increased gradually. At the protein level, imatinib induced the increase in HtrA2 protein level and concomitantly downregulated WT1 protein level. Subsequent to HtrA2 inhibition by UCF-101, the WT1 protein level decreased temporarily, but eventually increased. Imatinib induced apoptosis in K562 cells, but this effect was attenuated by the HtrA2 inhibitor UCF-101, resulting in the upregulation of the WT1 protein level. However; UCF-101 did not markedly change the proliferation inhibition caused by imatinib. Imatinib activated the p38 mitogen activated protein kinase (p38 MAPK) signaling pathway in K562 cells, and UCF-101 affected the activation of imatinib in the p38 MAPK signaling pathway. Imatinib inhibited the extracellular signal-related kinase (ERK1/2) pathway markedly and persistently, but UCF-101 exhibited no notable effect on the inhibition of the ERK1/2 pathway. HtrA2 and its regulatory effect on WT1 may affect the sensitivity of BCR/ABL(+) cell lines to target therapy drugs through different mechanisms. Regulation of WT1 by HtrA2 occurs in K562 cells, and the regulation may affect the apoptosis of K562 cells under the stress caused by chemotherapeutic treatment. The p38 MAPK signaling pathway, which serves an important role in cell apoptosis, is a downstream pathway of this regulation.

Tyrosine kinase oncogenes abrogate interleukin-3 dependence of murine myeloid cells through signaling pathways involving c-myc: conditional regulation of c-myc transcription by temperature-sensitive v-abl.

PubMed Central

Cleveland, J L; Dean, M; Rosenberg, N; Wang, J Y; Rapp, U R

1989-01-01

Retroviral expression vectors carrying the tyrosine kinase oncogenes abl, fms, src, and trk abrogate the requirements of murine myeloid FDC-P1 cells for interleukin-3 (IL-3). Factor-independent clones constitutively express c-myc in the absence of IL-3, whereas in parental cultures c-myc transcription requires the presence of the ligand. To directly test the effect of a tyrosine kinase oncogene on c-myc expression, retroviral constructs containing three different temperature-sensitive mutants of v-abl were introduced into myeloid IL-3-dependent FDC-P1 and 32D cells. At the permissive temperature, clones expressing temperature-sensitive abl behaved like wild-type abl-containing cells in their growth properties and expressed c-myc constitutively. Temperature shift experiments demonstrated that both IL-3 abrogation and the regulation of c-myc expression correlated with the presence of functional v-abl. Induction of c-myc expression by reactivation of temperature-sensitive v-abl mimicked c-myc induction by IL-3 in that it did not require protein synthesis and occurred at the level of transcription, with effects on both initiation and a transcription elongation block. However, v-abl-regulated FDC-P1 cell growth differed from IL-3-regulated growth in that c-fos and junB, which are normally induced by IL-3, were not induced by activation of v-abl. Images PMID:2555703

Diet-induced obesity accelerates acute lymphoblastic leukemia progression in two murine models.

PubMed

Yun, Jason P; Behan, James W; Heisterkamp, Nora; Butturini, Anna; Klemm, Lars; Ji, Lingyun; Groffen, John; Müschen, Markus; Mittelman, Steven D

2010-10-01

Obesity is associated with an increased incidence of many cancers, including leukemia, although it is unknown whether leukemia incidence is increased directly by obesity or rather by associated genetic, lifestyle, health, or socioeconomic factors. We developed animal models of obesity and leukemia to test whether obesity could directly accelerate acute lymphoblastic leukemia (ALL) using BCR/ABL transgenic and AKR/J mice weaned onto a high-fat diet. Mice were observed until development of progressive ALL. Although obese and control BCR/ABL mice had similar median survival, older obese mice had accelerated ALL onset, implying a time-dependent effect of obesity on ALL. Obese AKR mice developed ALL significantly earlier than controls. The effect of obesity was not explained by WBC count, thymus/spleen weight, or ALL phenotype. However, obese AKR mice had higher leptin, insulin, and interleukin-6 levels than controls, and these obesity-related hormones all have potential roles in leukemia pathogenesis. In conclusion, obesity directly accelerates presentation of ALL, likely by increasing the risk of an early event in leukemogenesis. This is the first study to show that obesity can directly accelerate the progression of ALL. Thus, the observed associations between obesity and leukemia incidence are likely to be directly related to biological effects of obesity. ©2010 AACR.

Disruption of IKAROS activity in primitive chronic-phase CML cells mimics myeloid disease progression

PubMed Central

Beer, Philip A.; Knapp, David J. H. F.; Miller, Paul H.; Kannan, Nagarajan; Sloma, Ivan; Heel, Kathy; Babovic, Sonja; Bulaeva, Elizabeth; Rabu, Gabrielle; Terry, Jefferson; Druker, Brian J.; Loriaux, Marc M.; Loeb, Keith R.; Radich, Jerald P.; Erber, Wendy N.

2015-01-01

Without effective therapy, chronic-phase chronic myeloid leukemia (CP-CML) evolves into an acute leukemia (blast crisis [BC]) that displays either myeloid or B-lymphoid characteristics. This transition is often preceded by a clinically recognized, but biologically poorly characterized, accelerated phase (AP). Here, we report that IKAROS protein is absent or reduced in bone marrow blasts from most CML patients with advanced myeloid disease (AP or BC). This contrasts with primitive CP-CML cells and BCR-ABL1–negative acute myeloid leukemia blasts, which express readily detectable IKAROS. To investigate whether loss of IKAROS contributes to myeloid disease progression in CP-CML, we examined the effects of forced expression of a dominant-negative isoform of IKAROS (IK6) in CP-CML patients’ CD34+ cells. We confirmed that IK6 disrupts IKAROS activity in transduced CP-CML cells and showed that it confers on them features of AP-CML, including a prolonged increased output in vitro and in xenografted mice of primitive cells with an enhanced ability to differentiate into basophils. Expression of IK6 in CD34+ CP-CML cells also led to activation of signal transducer and activator of transcription 5 and transcriptional repression of its negative regulators. These findings implicate loss of IKAROS as a frequent step and potential diagnostic harbinger of progressive myeloid disease in CML patients. PMID:25370416

Molecular analyses of 15,542 patients with suspected BCR-ABL1-negative myeloproliferative disorders allow to develop a stepwise diagnostic workflow

PubMed Central

Schnittger, Susanne; Bacher, Ulrike; Eder, Christiane; Dicker, Frank; Alpermann, Tamara; Grossmann, Vera; Kohlmann, Alexander; Kern, Wolfgang; Haferlach, Claudia; Haferlach, Torsten

2012-01-01

We investigated 15,542 patients with suspected BCR-ABL1- negative myeloproliferative or myelodysplastic/myeloproliferative neoplasm (including 359 chronic myelomonocytic leukemia) by a molecular marker set. JAK2V617F was detected in the suspected categories as follows: polycythemia vera 88.3%, primary myelofibrosis 53.8%, essential thrombocythemia 50.2%, and not further classifiable myeloproliferative neoplasms 38.0%. JAK2 exon 12 mutations were detected in 40.0% JAK2V617F-negative suspected polycythemia vera, MPLW515 mutations in 13.2%JAK2V617F-negative primary myelofibrosis and 7.1% JAK2V617F-negative essential thrombocythemia. TET2 mutations were distributed across all entities but were most frequent in suspected chronic myelomonocytic leukemia (77.8%). CBL mutations were identified in suspected chronic myelomonocytic leukemia (13.9%), primary myelofibrosis (8.0%), and not further classifiable myeloproliferative neoplasm (7.0%). This leads to a stepwise workflow for suspected myeloproliferative neoplasms starting with JAK2V617F and investigating JAK2V617F-negative patients for JAK2 exon 12 or MPL mutations, respectively. In cases in which a myeloproliferative neoplasm cannot be established, analysis for TET2, CBL and EZH2 mutations may be indicated. PMID:22511494

Four-channel asymmetric Real-Time PCR hybridization probe assay: a rapid pre-screening method for critical BCR-ABL kinase domain mutations.

PubMed

Martinez-Serra, Jordi; Gutiérrez, Antonio; Marcús, Toni F; Soverini, Simona; Amat, Juan Carlos; Navarro-Palou, María; Ros, Teresa; Bex, Teresa; Ballester, Carmen; Bauça, Josep Miquel; SanFelix, Sara; Novo, Andrés; Vidal, Carmen; Santos, Carmen; Besalduch, Joan

2012-03-01

Within the laboratory protocols, used for the study of BCR-ABL resistance mutations in chronic myeloid leukemia patients treated with Imatinib, direct sequencing remains the reference method. Since the incidence of patients with a mutation-related loss of response is not very high, it is very useful in the routine laboratory to perform a fast pre-screening method. With this in mind, we have designed a new technique, based on a single Real-Time FRET-based PCR, followed by a study of melting peaks. This new tool, developed in a LightCycler 2.0, combines four different fluorescence channels for the simultaneous detection, in a single close tube, of critical mutations within the ABL kinase domain. Assay evaluation performed on 33 samples, previously genotyped by sequentiation, resulted in full concordance of results. This new methodology detects in a few steps the presence of critical mutations associated to Imatinib resistance. Copyright © 2012 Elsevier Inc. All rights reserved.

Novel mutations and their functional and clinical relevance in myeloproliferative neoplasms: JAK2, MPL, TET2, ASXL1, CBL, IDH and IKZF1

PubMed Central

Tefferi, A

2010-01-01

Myeloproliferative neoplasms (MPNs) originate from genetically transformed hematopoietic stem cells that retain the capacity for multilineage differentiation and effective myelopoiesis. Beginning in early 2005, a number of novel mutations involving Janus kinase 2 (JAK2), Myeloproliferative Leukemia Virus (MPL), TET oncogene family member 2 (TET2), Additional Sex Combs-Like 1 (ASXL1), Casitas B-lineage lymphoma proto-oncogene (CBL), Isocitrate dehydrogenase (IDH) and IKAROS family zinc finger 1 (IKZF1) have been described in BCR-ABL1-negative MPNs. However, none of these mutations were MPN specific, displayed mutual exclusivity or could be traced back to a common ancestral clone. JAK2 and MPL mutations appear to exert a phenotype-modifying effect and are distinctly associated with polycythemia vera, essential thrombocythemia and primary myelofibrosis; the corresponding mutational frequencies are ∼99, 55 and 65% for JAK2 and 0, 3 and 10% for MPL mutations. The incidence of TET2, ASXL1, CBL, IDH or IKZF1 mutations in these disorders ranges from 0 to 17% these latter mutations are more common in chronic (TET2, ASXL1, CBL) or juvenile (CBL) myelomonocytic leukemias, mastocytosis (TET2), myelodysplastic syndromes (TET2, ASXL1) and secondary acute myeloid leukemia, including blast-phase MPN (IDH, ASXL1, IKZF1). The functional consequences of MPN-associated mutations include unregulated JAK-STAT (Janus kinase/signal transducer and activator of transcription) signaling, epigenetic modulation of transcription and abnormal accumulation of oncoproteins. However, it is not clear as to whether and how these abnormalities contribute to disease initiation, clonal evolution or blastic transformation. PMID:20428194

Imatinib 800 mg daily induces deeper molecular responses than imatinib 400 mg daily: results of SWOG S0325, an intergroup randomized PHASE II trial in newly diagnosed chronic phase chronic myeloid leukaemia.

PubMed

Deininger, Michael W; Kopecky, Kenneth J; Radich, Jerald P; Kamel-Reid, Suzanne; Stock, Wendy; Paietta, Elisabeth; Emanuel, Peter D; Tallman, Martin; Wadleigh, Martha; Larson, Richard A; Lipton, Jeffrey H; Slovak, Marilyn L; Appelbaum, Frederick R; Druker, Brian J

2014-01-01

The standard dose of imatinib for newly diagnosed patients with chronic phase chronic myeloid leukaemia (CP-CML) is 400 mg daily (IM400), but the optimal dose is unknown. This randomized phase II study compared the rates of molecular, haematological and cytogenetic response to IM400 vs. imatinib 400 mg twice daily (IM800) in 153 adult patients with CP-CML. Dose adjustments for toxicity were flexible to maximize retention on study. Molecular response (MR) at 12 months was deeper in the IM800 arm (4-log reduction of BCR-ABL1 mRNA: 25% vs. 10% of patients, P = 0·038; 3-log reduction: 53% vs. 35%, P = 0·049). During the first 12 months BCR-ABL1 levels in the IM800 arm were an average 2·9-fold lower than in the IM400 arm (P = 0·010). Complete haematological response was similar, but complete cytogenetic response was higher with IM800 (85% vs. 67%, P = 0·040). Grade 3-4 toxicities were more common for IM800 (58% vs. 31%, P = 0·0007), and were most commonly haematological. Few patients have relapsed, progressed or died, but both progression-free (P = 0·048) and relapse-free (P = 0·031) survival were superior for IM800. In newly diagnosed CP-CML patients, IM800 induced deeper MRs than IM400, with a trend for improved progression-free and overall survival, but was associated with more severe toxicity. © 2013 John Wiley & Sons Ltd.

BCR expression is decreased in meningiomas showing loss of heterozygosity of 22q within a new minimal deletion region.

PubMed

Wozniak, K; Piaskowski, S; Gresner, S M; Golanska, E; Bieniek, E; Bigoszewska, K; Sikorska, B; Szybka, M; Kulczycka-Wojdala, D; Zakrzewska, M; Zawlik, I; Papierz, W; Stawski, R; Jaskolski, D J; Och, W; Sieruta, M; Liberski, P P; Rieske, P

2008-05-01

Neurofibromin 2 (NF2), located on chromosome arm 22q, has been established as a tumor suppressor gene involved in meningioma pathogenesis. In our study, we investigated 149 meningiomas to determine whether there are additional tumor suppressor genes localized on chromosome 22q, apart from NF2, that might be involved in meningioma pathogenesis. The LOH analysis on chromosome 22q identified two regions of deletion: the first one, which is limited to the NF2 gene locus, and the second one, which is outside this location. The new minimal deletion region (MDR) included the following genes: BCR (breakpoint cluster region), RAB36 (a member of RAS oncogene family), GNAZ [guanine nucleotide binding protein (G protein), alpha-z polypeptide], and RTDR1 (rhabdoid tumor deletion region gene 1). The expression levels of all these genes, including NF2, were subsequently analyzed by quantitative real-time polymerase chain reaction. We observed a significantly lowered expression level of NF2 in meningiomas with 22q loss of heterozygosity (LOH) within NF2 region compared to the one in meningiomas with 22q retention of heterozygosity (ROH, P<0.05). Similarly, BCR showed a significantly lowered expression in meningiomas with 22q LOH within the new MDR compared to cases with 22q ROH (P<0.05). Our data, together with the already published information considering BCR function suggest that BCR can be considered as a candidate tumor suppressor gene localized on chromosome 22q which may be involved in meningioma pathogenesis.

Chronic Myelogenous Leukemia

MedlinePlus

... to produce too much of a protein called tyrosine kinase. Tyrosine kinase promotes cancer by allowing certain blood cells ... leukemia, this process doesn't work properly. The tyrosine kinase caused by the BCR-ABL gene causes ...

Total-Body Irradiation With or Without Fludarabine Phosphate Followed By Donor Stem Cell Transplant in Treating Patients With Hematologic Cancer

ClinicalTrials.gov

2017-04-07

Acute Lymphoblastic Leukemia in Remission; Acute Myeloid Leukemia in Remission; Aggressive Non-Hodgkin Lymphoma; Chronic Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Diffuse Large B-Cell Lymphoma; Hematopoietic and Lymphoid Cell Neoplasm; Indolent Non-Hodgkin Lymphoma; Mantle Cell Lymphoma; Myelodysplastic/Myeloproliferative Neoplasm; Plasma Cell Myeloma; Refractory Chronic Lymphocytic Leukemia; Refractory Hodgkin Lymphoma; Waldenstrom Macroglobulinemia

Risk-Adapted Chemotherapy in Treating Younger Patients With Newly Diagnosed Standard-Risk Acute Lymphoblastic Leukemia or Localized B-Lineage Lymphoblastic Lymphoma

ClinicalTrials.gov

2018-03-19

Adult B Lymphoblastic Lymphoma; Childhood B Acute Lymphoblastic Leukemia; Childhood B Acute Lymphoblastic Leukemia With t(9;22)(q34;q11.2); BCR-ABL1; Childhood B Lymphoblastic Lymphoma; Down Syndrome; Stage I B Lymphoblastic Lymphoma; Stage II B Lymphoblastic Lymphoma; Untreated Adult Acute Lymphoblastic Leukemia; Untreated Childhood Acute Lymphoblastic Leukemia

Glycosylation of IgG B cell receptor (IgG BCR) in multiple myeloma: relationship between sialylation and the signal activity of IgG BCR.

PubMed

Ilić, Vesna; Milosević-Jovcić, Nadezda; Petrović, Sonja; Marković, Dragana; Stefanović, Gordana; Ristić, Tatjana

2008-05-01

Little is known about the glycosylation of the isotype switched B cell receptor (BCR) in multiple myeloma, and the way it might affect receptor function. In this work IgG BCRs isolated from the individual lysates of peripheral blood lymphocytes (PBL) of 32 patients with IgG multiple myeloma and healthy controls were investigated for the expression of sialic acid (SA), galactose (Gal) and N-acetylglucosamine (GlcNAc), the sugars known to specify the glycoforms of human serum IgG. The degree of glycosylation and signaling status of all 32 isolated myeloma IgG BCRs were correlated and compared with the glycosylation of the IgG paraproteins isolated from sera of the same patients. It was shown that BCR IgG in myeloma is more heavily sialylated when compared with normal controls, that the increased sialylation of IgG BCR is associated with higher levels of tyrosine phosphorylation (signaling activity) of the IgG BCR supramolecular complex and that BCR IgG and serum IgG paraprotein from the same patient differed in all cases in the levels of terminal sugar expression. The results suggest that the development of the malignant clone in MM from post-switch B cells expressing IgG BCR at their surfaces to plasma cells secreting IgG paraprotein may be followed by permanent glycosylation changes in the IgG molecules.

Detection of different Ikaros isoforms in human leukaemias using real-time quantitative polymerase chain reaction.

PubMed

Olivero, S; Maroc, C; Beillard, E; Gabert, J; Nietfeld, W; Chabannon, C; Tonnelle, C

2000-09-01

The Ikaros gene is an essential regulator in development and haematopoiesis. Dysregulated Ikaros gene expression participates in leukaemic processes, as evidenced in animal models, and by analyses of blast-cell populations from leukaemic patients. We used real-time quantitative polymerase chain reaction (PCR) to evaluate the relative abundance of several Ikaros transcript isoforms in a variety of leukaemic-cell samples. Total RNA was isolated from bone-marrow or blood-cell samples collected at diagnosis in children or adult patients, 18 of whom had acute myeloblastic leukaemia (AML), 61 of whom had acute lymphoblastic leukaemia (ALL) and 11 of whom had chronic myeloid leukaemia (CML). The ratio (Ik1 + Ik2)/(Ik1 + Ik2 + Ik4 + Ik7 + Ik8) ranged from 13.5% to 85% and was lower (P < 0. 05) in samples from patients with m-bcr-abl ALL. An alternative splicing resulting in the deletion of 30 nucleotides at the end of exon 6 was observed in leukaemic samples, and in normal thymus and bone marrow. Our results are consistent with previous reports and suggest that the pattern of expression of the different human Ikaros isoforms are not homogeneous among different subsets of leukaemias.

Rho kinase regulates the survival and transformation of cells bearing oncogenic forms of KIT, FLT3 and BCR-ABL

PubMed Central

Mali, Raghuveer Singh; Ramdas, Baskar; Ma, Peilin; Shi, Jianjian; Munugalavadla, Veerendra; Sims, Emily; Wei, Lei; Vemula, Sasidhar; Nabinger, Sarah C.; Goodwin, Charles B.; Chan, Rebecca J.; Traina, Fabiola; Visconte, Valeria; Tiu, Ramon V.; Lewis, Timothy A.; Stern, Andrew M.; Wen, Qiang; Crispino, John D.; Boswell, H. Scott; Kapur, Reuben

2011-01-01

Summary We show constitutive activation of Rho kinase (ROCK) in cells bearing oncogenic forms of KIT, FLT3 and BCR-ABL, which is dependent on PI3K and Rho GTPase. Genetic or pharmacologic inhibition of ROCK in oncogene bearing cells impaired their growth as well as the growth of acute myeloid leukemia patient derived blasts and prolonged the life span of mice bearing myeloproliferative disease. Downstream from ROCK, rapid dephosphorylation or loss of expression of myosin light chain resulted in enhanced apoptosis, reduced growth and loss of actin polymerization in oncogene bearing cells leading to significantly prolonged life span of leukemic mice. In summary, we describe a pathway involving PI3K/Rho/ROCK/MLC which may contribute to myeloproliferative disease and/or acute myeloid leukemia in humans. PMID:21907926

Hydroxychavicol, a Piper betle leaf component, induces apoptosis of CML cells through mitochondrial reactive oxygen species-dependent JNK and endothelial nitric oxide synthase activation and overrides imatinib resistance.

PubMed

Chakraborty, Jayashree B; Mahato, Sanjit K; Joshi, Kalpana; Shinde, Vaibhav; Rakshit, Srabanti; Biswas, Nabendu; Choudhury Mukherjee, Indrani; Mandal, Labanya; Ganguly, Dipyaman; Chowdhury, Avik A; Chaudhuri, Jaydeep; Paul, Kausik; Pal, Bikas C; Vinayagam, Jayaraman; Pal, Churala; Manna, Anirban; Jaisankar, Parasuraman; Chaudhuri, Utpal; Konar, Aditya; Roy, Siddhartha; Bandyopadhyay, Santu

2012-01-01

Alcoholic extract of Piper betle (Piper betle L.) leaves was recently found to induce apoptosis of CML cells expressing wild type and mutated Bcr-Abl with imatinib resistance phenotype. Hydroxy-chavicol (HCH), a constituent of the alcoholic extract of Piper betle leaves, was evaluated for anti-CML activity. Here, we report that HCH and its analogues induce killing of primary cells in CML patients and leukemic cell lines expressing wild type and mutated Bcr-Abl, including the T315I mutation, with minimal toxicity to normal human peripheral blood mononuclear cells. HCH causes early but transient increase of mitochondria-derived reactive oxygen species. Reactive oxygen species-dependent persistent activation of JNK leads to an increase in endothelial nitric oxide synthase-mediated nitric oxide generation. This causes loss of mitochondrial membrane potential, release of cytochrome c from mitochondria, cleavage of caspase 9, 3 and poly-adenosine diphosphate-ribose polymerase leading to apoptosis. One HCH analogue was also effective in vivo in SCID mice against grafts expressing the T315I mutation, although to a lesser extent than grafts expressing wild type Bcr-Abl, without showing significant bodyweight loss. Our data describe the role of JNK-dependent endothelial nitric oxide synthase-mediated nitric oxide for anti-CML activity of HCH and this molecule merits further testing in pre-clinical and clinical settings. © 2011 Japanese Cancer Association.

In silico identification of novel kinase inhibitors targeting wild-type and T315I mutant ABL1 from FDA-approved drugs.

PubMed

Xu, Huai-long; Wang, Zi-jie; Liang, Xiao-meng; Li, Xin; Shi, Zheng; Zhou, Nan; Bao, Jin-ku

2014-06-01

The constitutively active fusion protein BCR-ABL1 is the major cause of chronic myeloid leukemia (CML), and selective inhibition of ABL1 is a promising approach for the treatment of CML. Reported drugs worked well in clinical practice, such as imatinib, dasatinib, nilotinib and bosutinib. However, resistance arises due to ABL1 mutation in patients, especially the T315I gate-keeper mutation. Thus, wide spectrum drugs targeting ABL1 are urgently needed. In order to screen potential drugs targeting wild-type ABL1 and T315I mutant ABL1, 1408 FDA approved small molecule drugs were subjected to molecular docking. With subsequent molecular dynamic (MD) simulation and MM/GBSA binding free energy calculation and energy decomposition, we identified chlorhexidine and sorafenib as potential "new use" drugs targeting wild-type ABL1, while nicergoline and plerixafor targeted T315I ABL1. Meanwhile, we also found that residues located in the ATP-binding site and A-loop motif played key roles in drug discovery towards ABL1. These findings may not only serve as a paradigm for the repositioning of existing approved drugs, but also instill new vitality to ABL1-targeted anti-CML therapeutics.

Effects of type I/type II interferons and transforming growth factor-beta on B-cell differentiation and proliferation. Definition of costimulation and cytokine requirements for immunoglobulin synthesis and expression.

PubMed

Estes, D M; Tuo, W; Brown, W C; Goin, J

1998-12-01

In this report, we sought to determine the role of selected type I interferons [interferon-alpha (IFN-alpha) and interferon-tau (IFN-tau)], IFN-gamma and transforming growth factor-beta (TGF-beta) in the regulation of bovine antibody responses. B cells were stimulated via CD40 in the presence or absence of B-cell receptor (BCR) cross-linking. IFN-alpha enhanced IgM, IgG2 and IgA responses but did not enhance IgG1 responses. BCR signalling alone was more effective at inducing IgG2 responses with IFN-alpha than dual cross-linking with CD40. Recombinant ovine IFN-tau was less effective at inducing IgG2 responses when compared with IFN-alpha, though IgA responses were similar in magnitude following BCR cross-linking. At higher concentrations, IFN-tau enhanced IgA responses greater than twofold over the levels observed with IFN-alpha. Previous studies have shown that addition of IFN-gamma to BCR or pokeweed mitogen-activated bovine B cells stimulates IgG2 production. However, following CD40 stimulation alone, IFN-gamma was relatively ineffective at stimulating high-rate synthesis of any non-IgM isotype. Dual cross-linking via CD40 and the BCR resulted in decreased synthesis of IgM with a concomitant increase in IgA and similar levels of IgG2 production to those obtained via the BCR alone. We also assessed the effects of endogenous and exogenous TGF-beta on immunoglobulin synthesis by bovine B cells. Exogenous TGF-beta stimulates both IgG2 and IgA production following CD40 and BCR cross-linking in the presence of IL-2. Blocking endogenous TGF-beta did not inhibit the up-regulation of IgG2 or IgA by interferons.

Investigating the role of the IGF axis as a predictor of biochemical recurrence in prostate cancer patients post-surgery.

PubMed

Breen, Kieran J; O'Neill, Amanda; Murphy, Lisa; Fan, Yue; Boyce, Susie; Fitzgerald, Noel; Dorris, Emma; Brady, Lauren; Finn, Stephen P; Hayes, Brian D; Treacy, Ann; Barrett, Ciara; Aziz, Mardiana Abdul; Kay, Elaine W; Fitzpatrick, John M; Watson, R William G

2017-09-01

Between 20% and 35% of prostate cancer (PCa) patients who undergo treatment with curative intent (ie, surgery or radiation therapy) for localized disease will experience biochemical recurrence (BCR). Alterations in the insulin-like growth factor (IGF) axis and PTEN expression have been implicated in the development and progression of several human tumors including PCa. We examined the expression of the insulin receptor (INSR), IGF-1 receptor (IGF-1R), PTEN, and AKT in radical prostatectomy tissue of patients who developed BCR post-surgery. Tissue microarrays (TMA) of 130 patients post-radical prostatectomy (65 = BCR, 65 = non-BCR) were stained by immunohistochemistry for INSR, IGF-1R, PTEN, and AKT using optimized antibody protocols. INSR, IGF1-R, PTEN, and AKT expression between benign and cancerous tissue, and different Gleason grades was assessed. Kaplan-Meier survival curves were used to examine the relationship between proteins expression and BCR. INSR (P < 0.001), IGF-1R (P < 0.001), and AKT (P < 0.05) expression was significantly increased and PTEN (P < 0.001) was significantly decreased in cancerous versus benign tissue. There was no significant difference in INSR, IGF-1R, or AKT expression in the cancerous tissue of non-BCR versus BCR patients (P = 0.149, P = 0.990, P = 0.399, respectively). There was a significant decrease in PTEN expression in the malignant tissue of BCR versus non-BCR patients (P = 0.011). Combinational analysis of the tissue proteins identified a combination of decreased PTEN and increased AKT or increased INSR was associated with worst outcome. We found that in each case, our hypothesized worst group was most likely to experience BCR and this was significant for combinations of PTEN+INSR and PTEN+AKT but not PTEN+IGF-1R (P = 0.023, P = 0.028, P = 0.078, respectively). Low PTEN is associated with BCR and this association is strongly modified by high INSR and high AKT expression. Measurement of these proteins could help inform appropriate patient selection for postoperative adjuvant therapy and prevent BCR. © 2017 Wiley Periodicals, Inc.

Bcr-Abl-independent mechanism of resistance to imatinib in K562 cells: Induction of cyclooxygenase-2 (COX-2) by histone deacetylases (HDACs).

PubMed

Kalle, Arunasree M; Sachchidanand, Sachchidanand; Pallu, Reddanna

2010-09-01

Our previous studies have shown that overexpression of MDR1 and cyclooygenase-2 (COX-2) resulted in resistance development to imatinib in chronic myelogenous leukemia (CML) K562 (IR-K562) cells. In the present study, the regulatory mechanism of MDR1 induction by COX-2 was investigated. A gradual overexpression of MDR1 and COX-2 during the process of development was observed. Furthermore, down regulation of MDR1 upon COX-2 knockdown by siRNA showed a decrease in the PKC levels and activation of PKC by addition of PGE(2) to K562 cells, suggesting a role for PKC in the COX-2 mediated induction of MDR1. The present study demonstrates COX-2 induction by HDACs and MDR1 induction by COX-2 via PGE(2)-cAMP-PKC-mediated pathway. Copyright 2010 Elsevier Ltd. All rights reserved.

Elucidating the Mechanism of p27 Inactivation by the Bcr-Abl Tyrosine Kinase

DTIC Science & Technology

2005-10-01

Grants 2002- Leukemia Research Fund Membership in Scientific Committees 2000- Molecular diagnostics (German competence network acute...transplantation, including reduced intensity conditioning. Hematological Diagnostics Standard morphology. Supervised molecular diagnostics in the

Sentinel Lymph Node Dissection to Select Clinically Node-negative Prostate Cancer Patients for Pelvic Radiation Therapy: Effect on Biochemical Recurrence and Systemic Progression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grivas, Nikolaos, E-mail: n.grivas@nki.nl; Wit, Esther; Pos, Floris

Purpose: To assess the efficacy of robotic-assisted laparoscopic sentinel lymph node (SLN) dissection (SLND) to select those patients with prostate cancer (PCa) who would benefit from additional pelvic external beam radiation therapy and long-term androgen deprivation therapy (ADT). Methods and Materials: Radioisotope-guided SLND was performed in 224 clinically node-negative patients scheduled to undergo external beam radiation therapy. Patients with histologically positive SLNs (pN1) were also offered radiation therapy to the pelvic lymph nodes, combined with 3 years of ADT. Biochemical recurrence (BCR), overall survival, and metastasis-free (including pelvic and nonregional lymph nodes) survival (MFS) rates were retrospectively calculated. The Briganti andmore » Kattan nomogram predictions were compared with the observed pN status and BCR. Results: The median prostate-specific antigen (PSA) value was 15.4 ng/mL (interquartile range [IQR] 8-29). A total number of 834 SLNs (median 3 per patient; IQR 2-5) were removed. Nodal metastases were diagnosed in 42% of the patients, with 150 SLNs affected (median 1; IQR 1-2). The 5-year BCR-free and MFS rates for pN0 patients were 67.9% and 87.8%, respectively. The corresponding values for pN1 patients were 43% and 66.6%. The PSA level and number of removed SLNs were independent predictors of BCR and MFS, and pN status was an additional independent predictor of BCR. The 5-year overall survival rate was 97.6% and correlated only with pN status. The predictive accuracy of the Briganti nomogram was 0.665. Patients in the higher quartiles of Kattan nomogram prediction of BCR had better than expected outcomes. The complication rate from SLND was 8.9%. Conclusions: For radioisotope-guided SLND, the high staging accuracy is accompanied by low morbidity. The better than expected outcomes observed in the lower quartiles of BCR prediction suggest a role for SLN biopsy as a potential selection tool for the addition of pelvic radiation therapy and ADT intensification in pN1 patients.« less

JAK2/STAT5 inhibition by nilotinib with ruxolitinib contributes to the elimination of CML CD34+ cells in vitro and in vivo

PubMed Central

Gallipoli, Paolo; Cook, Amy; Rhodes, Susan; Hopcroft, Lisa; Wheadon, Helen; Whetton, Anthony D.; Jørgensen, Heather G.; Bhatia, Ravi

2014-01-01

Chronic myeloid leukemia (CML) stem cell survival is not dependent on BCR-ABL protein kinase and treatment with ABL tyrosine kinase inhibitors cures only a minority of CML patients, thus highlighting the need for novel therapeutic targets. The Janus kinase (JAK)2/signal transducer and activator of transcription (STAT)5 pathway has recently been explored for providing putative survival signals to CML stem/progenitor cells (SPCs) with contradictory results. We investigated the role of this pathway using the JAK2 inhibitor, ruxolitinib (RUX). We demonstrated that the combination of RUX, at clinically achievable concentrations, with the specific and potent tyrosine kinase inhibitor nilotinib, reduced the activity of the JAK2/STAT5 pathway in vitro relative to either single agent alone. These effects correlated with increased apoptosis of CML SPCs in vitro and a reduction in primitive quiescent CML stem cells, including NOD.Cg-Prkdcscid IL2rgtm1Wjl /SzJ mice repopulating cells, induced by combination treatment. A degree of toxicity toward normal SPCs was observed with the combination treatment, although this related to mature B-cell engraftment in NOD.Cg-Prkdcscid IL2rgtm1Wjl /SzJ mice with minimal effects on primitive CD34+ cells. These results support the JAK2/STAT5 pathway as a relevant therapeutic target in CML SPCs and endorse the current use of nilotinib in combination with RUX in clinical trials to eradicate persistent disease in CML patients. PMID:24957147

Chemotherapy, Total Body Irradiation, and Post-Transplant Cyclophosphamide in Reducing Rates of Graft Versus Host Disease in Patients With Hematologic Malignancies Undergoing Donor Stem Cell Transplant

ClinicalTrials.gov

2018-03-05

Acute Myeloid Leukemia in Remission; Adult Acute Lymphoblastic Leukemia in Complete Remission; Chronic Myelogenous Leukemia, BCR-ABL1 Positive in Remission; Chronic Myelomonocytic Leukemia in Remission; Graft Versus Host Disease; Hodgkin Lymphoma; Minimal Residual Disease; Myelodysplastic Syndrome; Myeloproliferative Neoplasm; Non-Hodgkin Lymphoma; Plasma Cell Myeloma; Severe Aplastic Anemia; Waldenstrom Macroglobulinemia

EphB4-HSA Fusion Protein and Cytarabine /or Liposomal Vincristine in Patients With Recurrent or Refractory Acute Leukemia

ClinicalTrials.gov

2018-05-08

Acute Myeloid Leukemia Arising From Previous Myelodysplastic Syndrome; Blasts 5 Percent or More of Bone Marrow Nucleated Cells; Myelodysplastic/Myeloproliferative Neoplasm; Philadelphia Chromosome Positive; Recurrent Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Refractory Acute Lymphoblastic Leukemia; Refractory Acute Myeloid Leukemia; Refractory Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Secondary Acute Myeloid Leukemia; T Acute Lymphoblastic Leukemia

Infusion of Expanded Cord Blood Cells in Addition to Single Cord Blood Transplant in Treating Patients With Acute Leukemia, Chronic Myeloid Leukemia, or Myelodysplastic Syndromes

ClinicalTrials.gov

2018-03-26

Acute Biphenotypic Leukemia; Acute Lymphoblastic Leukemia in Remission; Acute Myeloid Leukemia in Remission; Blasts Under 10 Percent of Bone Marrow Nucleated Cells; Blasts Under 5 Percent of Bone Marrow Nucleated Cells; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Cytogenetic Abnormality; High Risk Myelodysplastic Syndrome; Myelodysplastic Syndrome With Excess Blasts; Pancytopenia; Refractory Anemia

Collecting and Storing Malignant, Borderline Malignant Neoplasms, and Related Samples From Young Patients With Cancer

ClinicalTrials.gov

2017-12-11

Acute Undifferentiated Leukemia; Atypical Chronic Myeloid Leukemia, BCR-ABL1 Negative; Childhood Acute Lymphoblastic Leukemia; Childhood Acute Myeloid Leukemia/Other Myeloid Malignancies; Childhood Chronic Myelogenous Leukemia; Chronic Lymphocytic Leukemia; Hairy Cell Leukemia; Juvenile Myelomonocytic Leukemia; Mast Cell Leukemia; Neoplasm of Uncertain Malignant Potential; Prolymphocytic Leukemia; Secondary Acute Myeloid Leukemia; T-cell Large Granular Lymphocyte Leukemia; Unspecified Childhood Solid Tumor, Protocol Specific

New Drugs for CML

DTIC Science & Technology

2007-02-01

collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services , Directorate...AC22, K1P and AC19 as well as the Furans A103 and A105 have qualities which distinguish them from previously reported CML cell inhibitory drugs and...cost in the quality of life for those individuals so treated (3). Imatinib, a specific inhibitor of the Bcr-Abl tyrosine protein kinase, has

Bruton's tyrosine kinase regulates B cell antigen receptor-mediated JNK1 response through Rac1 and phospholipase C-gamma2 activation.

PubMed

Inabe, Kazunori; Miyawaki, Toshio; Longnecker, Richard; Matsukura, Hiroyoshi; Tsukada, Satoshi; Kurosaki, Tomohiro

2002-03-13

Bruton's tyrosine kinase (Btk) is essential for B cell development and B cell antigen receptor (BCR) function. Recent studies have shown that Btk plays an important role in BCR-mediated c-Jun NH(2)-terminal kinase (JNK) 1 activation; however, the mechanism by which Btk participates in the JNK1 response remains elusive. Here we show that the BCR-mediated Rac1 activation is significantly inhibited by loss of Btk, while this Rac1 activation is not affected by loss of phospholipase C-gamma2 (PLC-gamma2). Since PLC-gamma2 is also required for BCR-mediated JNK1 response, our results suggest that Btk regulates Rac1 pathway as well as PLC-gamma2 pathway, both of which contribute to the BCR-mediated JNK1 response.

NLR Nod1 signaling promotes survival of BCR-engaged mature B cells through up-regulated Nod1 as a positive outcome

PubMed Central

Asano, Masanao; Li, Yue-Sheng; Núñez, Gabriel

2017-01-01

Although B cell development requires expression of the B cell antigen receptor (BCR), it remains unclear whether engagement of self-antigen provides a positive impact for most B cells. Here, we show that BCR engagement by self-ligand during development in vivo results in up-regulation of the Nod-like receptor member Nod1, which recognizes the products of intestinal commensal bacteria. In anti-thymocyte/Thy-1 autoreactive BCR knock-in mice lacking self–Thy-1 ligand, immunoglobulin light chain editing occurred, generating B cells with up-regulated Nod1, including follicular and marginal zone B cells with natural autoreactivity. This BCR editing with increased Nod1 resulted in preferential survival. In normal adult mice, most mature B cells are enriched for Nod1 up-regulated cells, and signaling through Nod1 promotes competitive survival of mature B cells. These findings demonstrate a role for microbial products in promoting survival of mature B cells through up-regulated Nod1, providing a positive effect of BCR engagement on development of most B cells. PMID:28878001

[The quantitative testing of V617F mutation in gen JAK2 using pyrosequencing technique].

PubMed

Dunaeva, E A; Mironov, K O; Dribnokhodova, T E; Subbotina, E E; Bashmakova; Ol'hovskiĭ, I A; Shipulin, G A

2014-11-01

The somatic mutation V617F in gen JAK2 is a frequent cause of chronic myeloprolific diseases not conditioned by BCR/ABL mutation. The quantitative testing of relative percentage of mutant allele can be used in establishing severity of disease and its prognosis and in prescription of remedy inhibiting activity of JAK2. To quantitatively test mutation the pyrosequencing technique was applied. The developed technique permits detecting and quantitatively, testing percentage of mutation fraction since 7%. The "gray zone" is presented by samples with percentage of mutant allele from 4% to 7%. The dependence of expected percentage of mutant fraction in analyzed sample from observed value of signal is described by equation of line with regression coefficients y = - 0.97, x = -1.32 and at that measurement uncertainty consists ± 0.7. The developed technique is approved officially on clinical material from 192 patients with main forms of myeloprolific diseases not conditioned by BCR/ABL mutation. It was detected 64 samples with mautant fraction percentage from 13% to 91%. The developed technique permits implementing monitoring of therapy of myeloprolific diseases and facilitates to optimize tactics of treatment.

Characterization of a new ARID family transcription factor (Brightlike/ARID3C) that co-activates Bright/ARID3A-mediated immunoglobulin gene transcription

PubMed Central

Tidwell, Josephine A.; Schmidt, Christian; Heaton, Phillip; Wilson, Van; Tucker, Philip W.

2011-01-01

Two members, Bright/ARID3A and Bdp/ARID3B, of the ARID (AT-Rich Interaction Domain) transcription family are distinguished by their ability to specifically bind to DNA and to self-associate via a second domain, REKLES. Bright and Bdp positively regulate immunoglobulin heavy chain gene (IgH) transcription by binding to AT-rich motifs within Matrix Associating Regions (MARs) residing within a subset of VH promoters and the Eµ intronic enhancer. In addition, REKLES provides Bright nuclear export function, and a small pool of Bright is directed to plasma membrane sub-domains/lipid rafts where it associates with and modulates signaling of the B cell antigen receptor (BCR). Here, we characterize a third, highly conserved, physically condensed ARID3 locus, Brightlike/ARID3C. Brightlike encodes two alternatively spliced, SUMO-I-modified isoforms that include or exclude (Δ6) the REKLES-encoding exon 6. Brightlike transcripts and proteins are expressed preferentially within B lineage lymphocytes and coordinate with highest Bright expression--in activated follicular B cells. Brightlike, but not BrightlikeΔ6, undergoes nuclear-cytoplasmic shuttling with a fraction localizing within lipid rafts following BCR stimulation. Brightlike, but not BrightlikeΔ6, associates with Bright in solution, at common DNA binding sites in vitro, and is enriched at Bright binding sites in chromatin. Although possessing little transactivation capacity of its own, Brightlike significantly co-activates Bright-dependent IgH transcription with maximal activity mediated by the unsumoylated form. In sum, this report introduces Brightlike as an additional functional member of the family of ARID proteins, which should be considered in regulatory circuits, previously ascribed to be mediated by Bright. PMID:21955986

Coexistence of translocation(1,19) and the Philadelphia chromosome in a child's first presentation of chronic myeloid leukemia in blast crisis treated with dasatinib.

PubMed

Eckardt, Mark A; Chang, Vivian Y; Rao, Nagesh P; Federman, Noah

2011-11-01

Chronic myelogenous leukemia (CML) constitutes less than 5% of childhood leukemias. The authors describe a rare case of a 14-year-old boy who presented with CML in blast crisis. Unique to this patient was the evidence of both breakpoint cluster region-c-abl oncogene 1 (BCR-ABL1) fusions as well as an additional unbalanced t(1;19) translocation. This combination has not previously been reported in the same patient. Initial treatment with dasatinib achieved a complete cytogenetic response within 2 months of therapy. This case highlights the heterogeneous presentation of CML in children and rationale for use of dasatinib as a first-line agent for patients with blast crisis.

A computational approach to the relationship between radiation induced double strand breaks and translocations

NASA Technical Reports Server (NTRS)

Holley, W. R.; Chatterjee, A.

1994-01-01

A theoretical framework is presented which provides a quantitative analysis of radiation induced translocations between the ab1 oncogene on CH9q34 and a breakpoint cluster region, bcr, on CH 22q11. Such translocations are associated frequently with chronic myelogenous leukemia. The theory is based on the assumption that incorrect or unfaithful rejoining of initial double strand breaks produced concurrently within the 200 kbp intron region upstream of the second abl exon, and the 16.5 kbp region between bcr exon 2 and exon 6 interact with each other, resulting in a fusion gene. for an x-ray dose of 100 Gy, there is good agreement between the theoretical estimate and the one available experimental result. The theory has been extended to provide dose response curves for these types of translocations. These curves are quadratic at low doses and become linear at high doses.

Low level exposure to inorganic mercury interferes with B cell receptor signaling in transitional type 1 B cells.

PubMed

Gill, R; McCabe, M J; Rosenspire, A J

2017-09-01

Mercury (Hg) has been implicated as a factor contributing to autoimmune disease in animal models and humans. However the mechanism by which this occurs has remained elusive. Since the discovery of B cells it has been appreciated by immunologists that during the normal course of B cell development, some immature B cells must be generated that produce immunoglobulin reactive to self-antigens (auto-antibodies). However in the course of normal development, the vast majority of immature auto-reactive B cells are prevented from maturing by processes collectively known as tolerance. Autoimmune disease arises when these mechanisms of tolerance are disrupted. In the B cell compartment, it is firmly established that tolerance depends in part upon negative selection of self-reactive immature (transitional type 1) B cells. In these cells negative selection depends upon signals generated by the B Cell Receptor (BCR), in the sense that those T1 B cells who's BCRs most strongly bind to, and so generate the strongest signals to self-antigens are neutralized. In this report we have utilized multicolor phosphoflow cytometry to show that in immature T1 B cells Hg attenuates signal generation by the BCR through mechanisms that may involve Lyn, a key tyrosine kinase in the BCR signal transduction pathway. We suggest that exposure to low, environmentally relevant levels of Hg, disrupts tolerance by interfering with BCR signaling in immature B cells, potentially leading to the appearance of mature auto-reactive B cells which have the ability to contribute to auto-immune disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Factors that mediate and prevent degradation of the inactive and unstable GudB protein in Bacillus subtilis

PubMed Central

Stannek, Lorena; Gunka, Katrin; Care, Rachel A.; Gerth, Ulf; Commichau, Fabian M.

2015-01-01

The Gram-positive model bacterium Bacillus subtilis contains two glutamate dehydro genase-encoding genes, rocG and gudB. While the rocG gene encodes the functional GDH, the gudB gene is cryptic (gudBCR) in the laboratory strain 168 due to a perfect 18 bp-long direct repeat that renders the GudB enzyme inactive and unstable. Although constitutively expressed the GudBCR protein can hardly be detected in B. subtilis as it is rapidly degraded within stationary growth phase. Its high instability qualifies GudBCR as a model substrate for studying protein turnover in B. subtilis. Recently, we have developed a visual screen to monitor the GudBCR stability in the cell using a GFP-GudBCR fusion. Using fluorescent microscopy we found that the GFP protein is simultaneously degraded together with GudBCR. This allows us to analyze the stability of GudBCR in living cells. By combining the visual screen with a transposon mutagenesis approach we looked for mutants that show an increased fluorescence signal compared to the wild type indicating a stabilized GFP-GudBCR fusion. We observed, that disruption of the arginine kinase encoding gene mcsB upon transposon insertion leads to increased amounts of the GFP-GudBCR fusion in this mutant. Deletion of the cognate arginine phosphatase YwlE in contrast results in reduced levels of the GFP-GudBCR fusion. Recently, it was shown that the kinase McsB is involved in phosphorylation of GudBCR on arginine residues. Here we show that selected arginine-lysine point mutations of GudBCR exhibit no influence on degradation. The activity of McsB and YwlE, however, are crucial for the activation and inhibition, respectively, of a proteolytic machinery that efficiently degrades the unstable GudBCR protein in B. subtilis. PMID:25610436

Efficacy of ponatinib against ABL tyrosine kinase inhibitor-resistant leukemia cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okabe, Seiichi, E-mail: okabe@tokyo-med.ac.jp; Tauchi, Tetsuzo; Tanaka, Yuko

2013-06-07

Highlights: •Efficacy of ponatinib against ABL tyrosine kinase inhibitor-resistant leukemia cells okabe et al. •Imatinib or nilotinib resistance was involved Src family kinase. •The BCR-ABL point mutation (E334V) was highly resistant to imatinib or nilotinib. •Ponatinib was a powerful strategy against imatinib or nilotinib resistant Ph-positive cells. -- Abstract: Because a substantial number of patients with chronic myeloid leukemia acquire resistance to ABL tyrosine kinase inhibitors (TKIs), their management remains a challenge. Ponatinib, also known as AP24534, is an oral multi-targeted TKI. Ponatinib is currently being investigated in a pivotal phase 2 clinical trial. In the present study, we analyzedmore » the molecular and functional consequences of ponatinib against imatinib- or nilotinib-resistant (R) K562 and Ba/F3 cells. The proliferation of imatinib- or nilotinib-resistant K562 cells did not decrease after treatment with imatinib or nilotinib. Src family kinase Lyn was activated. Point mutation Ba/F3 cells (E334 V) were also highly resistant to imatinib and nilotinib. Treatment with ponatinib for 72 h inhibited the growth of imatinib- and nilotinib-resistant cells. The phosphorylation of BCR-ABL, Lyn, and Crk-L was reduced. This study demonstrates that ponatinib has an anti-leukemia effect by reducing ABL and Lyn kinase activity and this information may be of therapeutic relevance.« less

Profile of bosutinib and its clinical potential in the treatment of chronic myeloid leukemia

PubMed Central

Amsberg, Gunhild Keller-von; Koschmieder, Steffen

2013-01-01

Bosutinib (SKI-606) is an orally available, once-daily, dual Src and Abl kinase inhibitor with promising clinical potential in first-, second-, and third-line treatment of chronic myeloid leukemia (CML). Bosutinib effectively inhibits wild-type BCR-ABL and most imatinib-resistant BCR-ABL mutations except for V299L and T315I. Low hematologic toxicity is a remarkable characteristic of this novel second-generation tyrosine kinase inhibitor, and this has been ascribed to its minimal activity against the platelet-derived growth factor receptor and KIT. Low-grade, typically self-limiting diarrhea, which usually appears within the first few weeks after treatment initiation, represents the predominant toxicity of bosutinib. Other treatment-associated adverse events are mostly mild to moderate. Bosutinib has been approved by the US Food and Drug Administration for the treatment of chronic, accelerated, or blast phase Philadelphia chromosome-positive CML in adult patients with resistance or intolerance to prior therapy. This review summarizes the main properties of bosutinib and the currently available data on its clinical potential in the treatment of CML. PMID:23493838

Differential regulation of the Rac1 GTPase-activating protein (GAP) BCR during oxygen/glucose deprivation in hippocampal and cortical neurons.

PubMed

Smith, Katharine R; Rajgor, Dipen; Hanley, Jonathan G

2017-12-08

Brain ischemia causes oxygen and glucose deprivation (OGD) in neurons, triggering a cascade of events leading to synaptic accumulation of glutamate. Excessive activation of glutamate receptors causes excitotoxicity and delayed cell death in vulnerable neurons. Following global cerebral ischemia, hippocampal CA1 pyramidal neurons are more vulnerable to injury than their cortical counterparts, but the mechanisms that underlie this difference are unclear. Signaling via Rho-family small GTPases, their upstream guanine nucleotide exchange factors, and GTPase-activating proteins (GAPs) is differentially dysregulated in response to OGD/ischemia in hippocampal and cortical neurons. Increased Rac1 activity caused by OGD/ischemia contributes to neuronal death in hippocampal neurons via diverse effects on NADPH oxidase activity and dendritic spine morphology. The Rac1 guanine nucleotide exchange factor Tiam1 mediates an OGD-induced increase in Rac1 activity in hippocampal neurons; however, the identity of an antagonistic GAP remains elusive. Here we show that the Rac1 GAP breakpoint cluster region (BCR) associates with NMDA receptors (NMDARs) along with Tiam1 and that this protein complex is more abundant in hippocampal compared with cortical neurons. Although total BCR is similar in the two neuronal types, BCR is more active in hippocampal compared with cortical neurons. OGD causes an NMDAR- and Ca 2+ -permeable AMPAR-dependent deactivation of BCR in hippocampal but not cortical neurons. BCR knockdown occludes OGD-induced Rac1 activation in hippocampal neurons. Furthermore, disrupting the Tiam1-NMDAR interaction with a fragment of Tiam1 blocks OGD-induced Tiam1 activation but has no effect on the deactivation of BCR. This work identifies BCR as a critical player in Rac1 regulation during OGD in hippocampal neurons. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

B Cell Receptor Signaling-Based Index as a Biomarker for the Loss of Peripheral Immune Tolerance in Autoreactive B Cells in Rheumatoid Arthritis

PubMed Central

Lyubchenko, Taras; Zerbe, Gary O.

2014-01-01

This study examines the loss of peripherally induced B cell immune tolerance in Rheumatoid arthritis (RA) and establishes a novel signaling-based measure of activation in a subset of autoreactive B cells - the Induced tolerance status index (ITSI). Naturally occurring naïve autoreactive B cells can escape the “classical” tolerogenic mechanisms of clonal deletion and receptor editing, but remain peripherally tolerized through B cell receptor (BCR) signaling inhibition (postdevelopmental “receptor tuning” or anergy). ITSI is a statistical index that numerically determines the level of homology between activation patterns of BCR signaling intermediaries in B cells that are either tolerized or activated by auto antigen exposure, and thus quantifies the level of peripheral immune tolerance. The index is based on the logistic regression analysis of phosphorylation levels in a panel of BCR signaling proteins. Our results demonstrate a new approach to identifying autoreactive B cells based on their BCR signaling features. PMID:25057856

DC-SIGN–expressing macrophages trigger activation of mannosylated IgM B-cell receptor in follicular lymphoma

PubMed Central

Amin, Rada; Mourcin, Frédéric; Uhel, Fabrice; Pangault, Céline; Ruminy, Philippe; Dupré, Loic; Guirriec, Marion; Marchand, Tony; Fest, Thierry; Lamy, Thierry

2015-01-01

Follicular lymphoma (FL) results from the accumulation of malignant germinal center (GC) B cells leading to the development of an indolent and largely incurable disease. FL cells remain highly dependent on B-cell receptor (BCR) signaling and on a specific cell microenvironment, including T cells, macrophages, and stromal cells. Importantly, FL BCR is characterized by a selective pressure to retain surface immunoglobulin M (IgM) BCR despite an active class-switch recombination process, and by the introduction, in BCR variable regions, of N-glycosylation acceptor sites harboring unusual high-mannose oligosaccharides. However, the relevance of these 2 FL BCR features for lymphomagenesis remains unclear. In this study, we demonstrated that IgM+ FL B cells activated a stronger BCR signaling network than IgG+ FL B cells and normal GC B cells. BCR expression level and phosphatase activity could both contribute to such heterogeneity. Moreover, we underlined that a subset of IgM+ FL samples, displaying highly mannosylated BCR, efficiently bound dendritic cell–specific intercellular adhesion molecule-3–grabbing nonintegrin (DC-SIGN), which could in turn trigger delayed but long-lasting BCR aggregation and activation. Interestingly, DC-SIGN was found within the FL cell niche in situ. Finally, M2 macrophages induced a DC-SIGN–dependent adhesion of highly mannosylated IgM+ FL B cells and triggered BCR-associated kinase activation. Interestingly, pharmacologic BCR inhibitors abolished such crosstalk between macrophages and FL B cells. Altogether, our data support an important role for DC-SIGN–expressing infiltrating cells in the biology of FL and suggest that they could represent interesting therapeutic targets. PMID:26272216

De-escalation of tyrosine kinase inhibitor dose in patients with chronic myeloid leukaemia with stable major molecular response (DESTINY): an interim analysis of a non-randomised, phase 2 trial.

PubMed

Clark, Richard E; Polydoros, Fotios; Apperley, Jane F; Milojkovic, Dragana; Pocock, Christopher; Smith, Graeme; Byrne, Jenny L; de Lavallade, Hugues; O'Brien, Stephen G; Coffey, Tony; Foroni, Letizia; Copland, Mhairi

2017-07-01

Discontinuation of tyrosine kinase inhibitor (TKI) therapy is feasible for some patients with chronic myeloid leukaemia with deep molecular responses; however, patients with stable major molecular response (MMR), but not MR4, have not been studied, nor has the effect of treatment de-escalation rather than outright cessation. We aimed to examine the effects of treatment de-escalation as a prelude to complete cessation, not only in patients with MR4 or greater, but also in those with MMR but not MR4. We did this interim analysis of a non-randomised, phase 2 trial at 20 hospitals in the UK. We recruited patients (aged ≥18 years) with chronic myeloid leukaemia in first chronic phase who had received TKI for 3 years or more and were either in stable MR4 (BCR-ABL1:ABL1 ratio <0·01%; MR4 cohort) or in stable MMR (BCR-ABL1:ABL1 ratio consistently <0·1%) but not MR4 (MMR cohort) for 12 months or longer. Participants received half their standard TKI dose (imatinib 200 mg daily, dasatinib 50 mg daily, or nilotinib 200 mg twice daily) for 12 months. Molecular recurrence was defined as loss of MMR (BCR-ABL1:ABL1 ratio >0·1%) on two consecutive samples. The primary endpoint of this interim analysis was the proportion of patients who lost MMR on de-escalation and regained MMR on TKI resumption. Analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01804985. Between Dec 16, 2013 and April 10, 2015, we enrolled 174 patients into the MMR cohort (n=49) or the MR4 cohort (n=125). During the 12 months of half-dose therapy, 12 patients (7%) had molecular recurrence, all of whom regained MMR within 4 months of full-dose TKI resumption (median time to recovery 77 days). Recurrence was significantly lower in the MR4 cohort (three [2%; 90% CI 0·2-4·8] of 121 evaluable patients) than in the MMR cohort (nine [19%; 90% CI 9·5-28·0] of 48 evaluable patients; hazard ratio 0·12, 90% CI 0·04-0·37; p=0·0007), but was unrelated to previous TKI or TKI therapy duration. Adverse events (eg, lethargy, diarrhoea, rash, and nausea) improved during the first 3 months of de-escalation, though not thereafter. 16 serious adverse events were reported, including one fatality due to worsening pre-existing peripheral arterial occlusive disease in a patient who had received only imatinib. TKI de-escalation is safe for most patients with excellent responses to TKI therapy, and is associated with improvement in symptoms. These findings show that lower TKI doses might maintain responses in these patients, implying that such patients could be unnecessarily overtreated. Studies of more ambitious de-escalation are warranted. Newcastle University and Bloodwise. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fludarabine Phosphate and Total Body Irradiation Followed by a Donor Peripheral Stem Cell Transplant in Treating Patients With Myelodysplastic Syndromes or Myeloproliferative Disorders

ClinicalTrials.gov

2018-03-28

Atypical Chronic Myeloid Leukemia, BCR-ABL1 Negative; Chronic Myelomonocytic Leukemia; de Novo Myelodysplastic Syndrome; Essential Thrombocythemia; Myeloproliferative Neoplasm; Paroxysmal Nocturnal Hemoglobinuria; Polycythemia Vera; Polycythemia Vera, Post-Polycythemic Myelofibrosis Phase; Primary Myelofibrosis; Refractory Anemia; Refractory Anemia With Excess Blasts; Refractory Anemia With Ring Sideroblasts; Refractory Cytopenia With Multilineage Dysplasia; Refractory Cytopenia With Multilineage Dysplasia and Ring Sideroblasts

Engineering and Functional Characterization of Fusion Genes Identifies Novel Oncogenic Drivers of Cancer. | Office of Cancer Genomics

Cancer.gov

Oncogenic gene fusions drive many human cancers, but tools to more quickly unravel their functional contributions are needed. Here we describe methodology permitting fusion gene construction for functional evaluation. Using this strategy, we engineered the known fusion oncogenes, BCR-ABL1, EML4-ALK, and ETV6-NTRK3, as well as 20 previously uncharacterized fusion genes identified in TCGA datasets.

Comparison of Triple GVHD Prophylaxis Regimens for Nonmyeloablative or Reduced Intensity Conditioning Unrelated Mobilized Blood Cell Transplantation

ClinicalTrials.gov

2018-05-09

Acute Lymphoblastic Leukemia; Acute Myeloid Leukemia; Aggressive Non-Hodgkin Lymphoma; Chronic Lymphocytic Leukemia; Diffuse Large B-Cell Lymphoma; Hematopoietic Cell Transplantation Recipient; Loss of Chromosome 17p; Mantle Cell Lymphoma; Myelodysplastic Syndrome; Myelodysplastic/Myeloproliferative Neoplasm; Prolymphocytic Leukemia; Recurrent Chronic Lymphocytic Leukemia; Recurrent Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Recurrent Hodgkin Lymphoma; Recurrent Plasma Cell Myeloma; Recurrent Small Lymphocytic Lymphoma; Recurrent Waldenstrom Macroglobulinemia

Enhancement of B-cell receptor signaling by a point mutation of adaptor protein 3BP2 identified in human inherited disease cherubism.

PubMed

Ogi, Kazuhiro; Nakashima, Kenji; Chihara, Kazuyasu; Takeuchi, Kenji; Horiguchi, Tomoko; Fujieda, Shigeharu; Sada, Kiyonao

2011-09-01

Tyrosine phosphorylation of adaptor protein c-Abl-Src homology 3 (SH3) domain-binding protein-2 (3BP2, also referred to SH3BP2) positively regulates the B-cell antigen receptor (BCR)-mediated signal transduction, leading to the activation of nuclear factor of activated T cells (NFAT). Here we showed the effect of the proline to arginine substitution of 3BP2 in which is the most common mutation in patients with cherubism (P418R) on B-cell receptor signaling. Comparing to the wild type, overexpression of the mutant form of 3BP2 (3BP2-P416R, corresponding to P418R in human protein) enhanced BCR-mediated activation of NFAT. 3BP2-P416R increased the signaling complex formation with Syk, phospholipase C-γ2 (PLC-γ2), and Vav1. In contrast, 3BP2-P416R could not change the association with the negative regulator 14-3-3. Loss of the association mutant that was incapable to associate with 14-3-3 could not mimic BCR-mediated NFAT activation in Syk-deficient cells. Moreover, BCR-mediated phosphorylation of extracellular signal regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) was not affected by P416R mutation. These results showed that P416R mutation of 3BP2 causes the gain of function in B cells by increasing the interaction with specific signaling molecules. © 2011 The Authors. Journal compilation © 2011 by the Molecular Biology Society of Japan/Blackwell Publishing Ltd.

The Gab1 docking protein links the b cell antigen receptor to the phosphatidylinositol 3-kinase/Akt signaling pathway and to the SHP2 tyrosine phosphatase.

PubMed

Ingham, R J; Santos, L; Dang-Lawson, M; Holgado-Madruga, M; Dudek, P; Maroun, C R; Wong, A J; Matsuuchi, L; Gold, M R

2001-04-13

B cell antigen receptor (BCR) signaling causes tyrosine phosphorylation of the Gab1 docking protein. This allows phosphatidylinositol 3-kinase (PI3K) and the SHP2 tyrosine phosphatase to bind to Gab1. In this report, we tested the hypothesis that Gab1 acts as an amplifier of PI3K- and SHP2-dependent signaling in B lymphocytes. By overexpressing Gab1 in the WEHI-231 B cell line, we found that Gab1 can potentiate BCR-induced phosphorylation of Akt, a PI3K-dependent response. Gab1 expression also increased BCR-induced tyrosine phosphorylation of SHP2 as well as the binding of Grb2 to SHP2. We show that the pleckstrin homology (PH) domain of Gab1 is required for BCR-induced phosphorylation of Gab1 and for Gab1 participation in BCR signaling. Moreover, using confocal microscopy, we show that BCR ligation can induce the translocation of Gab1 from the cytosol to the plasma membrane and that this requires the Gab1 PH domain as well as PI3K activity. These findings are consistent with a model in which the binding of the Gab1 PH domain to PI3K-derived lipids brings Gab1 to the plasma membrane, where it can be tyrosine-phosphorylated and then act as an amplifier of BCR signaling.

The impact of medical insurance coverage and molecular monitoring frequency on outcomes in chronic myeloid leukemia: real-world evidence in China.

PubMed

Sheng, Guangying; Chen, Suning; Zhang, Ri; Miao, Miao; Wu, Depei; Tan, Seng Chuen; Liu, Chao; Xiong, Tengbin

2017-04-01

Imatinib (Glivec) has been covered by critical disease insurance for treatment of chronic myeloid leukemia (CML) in Jiangsu province of China since 2013. Further, free molecular monitoring has been provided to patients at top clinical centers as part of a pilot study that has changed the local treatment pattern and outcomes of patients with CML. This study evaluates the impact of medical insurance coverage and the molecular monitoring frequency on outcomes of patients with CML treated at a central hospital in Jiangsu, China, according to patient-level data. The study investigated 335 CML patients receiving medical treatment in a central hospital between January 1, 2011 and December 31, 2014. Demographic and clinical characteristics were extracted from the patients' clinical records. Univariate and multivariate analyses using the logistic regression model were performed to identify the differences in outcomes of major molecular response (MMR) or complete cytogenetic response (CCyR) between patients who were insured vs uninsured, or between patients with frequency of PCR monitoring ≤2 times vs ≥3 times per year. Both the achievement of MMR (BCR-ABL IS ≤0.1%) (50.4% vs 37.5%) and CCyR (80.7% vs 62.8%) at 12 months have shown significant differences that favored patients with insurance coverage of imatinib, while there was no significant difference in the outcome of BCR-ABL IS ≤1% between insured and non-insured groups (56.0% vs 51.3%) at 6 months. The long-term results at 24 months demonstrated that there was a statistically significant difference in MMR rates between the group with 3 or more PCR monitoring tests per year and the group of patients with 2 or less PCR tests per year (76.9% vs 52.2%). The study findings suggest that CML patients benefit from insurance coverage of imatinib and higher frequency (≥3) of regularly scheduled molecular monitoring PCR in China.

Tacrolimus and Mycophenolate Mofetil With or Without Sirolimus in Preventing Acute Graft-Versus-Host Disease in Patients Who Are Undergoing Donor Stem Cell Transplant for Hematologic Cancer

ClinicalTrials.gov

2018-02-08

Myelodysplastic/Myeloproliferative Neoplasm, Unclassifiable; Previously Treated Myelodysplastic Syndrome; Refractory Chronic Lymphocytic Leukemia; Refractory Plasma Cell Myeloma; Waldenstrom Macroglobulinemia; Accelerated Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Adult Acute Lymphoblastic Leukemia in Remission; Adult Acute Myeloid Leukemia in Remission; Adult Acute Myeloid Leukemia With t(9;11)(p22;q23); MLLT3-MLL; Adult Acute Myeloid Leukemia With Inv(16)(p13.1q22); CBFB-MYH11; Adult Acute Promyelocytic Leukemia With t(15;17)(q22;q12); PML-RARA; Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); RUNX1-RUNX1T1; Atypical Chronic Myeloid Leukemia, BCR-ABL1 Negative; Blast Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Childhood Acute Lymphoblastic Leukemia in Remission; Childhood Acute Myeloid Leukemia in Remission; Childhood Burkitt Lymphoma; Childhood Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Childhood Diffuse Large Cell Lymphoma; Childhood Immunoblastic Lymphoma; Childhood Myelodysplastic Syndrome; Stage II Contiguous Adult Burkitt Lymphoma; Stage II Contiguous Adult Diffuse Large Cell Lymphoma; Stage II Contiguous Adult Diffuse Mixed Cell Lymphoma; Stage II Contiguous Adult Diffuse Small Cleaved Cell Lymphoma; Stage II Adult Contiguous Immunoblastic Lymphoma; Stage II Contiguous Adult Lymphoblastic Lymphoma; Stage II Grade 1 Contiguous Follicular Lymphoma; Stage II Grade 2 Contiguous Follicular Lymphoma; Stage II Grade 3 Contiguous Follicular Lymphoma; Stage II Contiguous Mantle Cell Lymphoma; Stage II Non-Contiguous Adult Burkitt Lymphoma; Stage II Non-Contiguous Adult Diffuse Large Cell Lymphoma; Stage II Non-Contiguous Adult Diffuse Mixed Cell Lymphoma; Stage II Non-Contiguous Adult Diffuse Small Cleaved Cell Lymphoma; Stage II Adult Non-Contiguous Immunoblastic Lymphoma; Stage II Non-Contiguous Adult Lymphoblastic Lymphoma; Stage II Grade 1 Non-Contiguous Follicular Lymphoma; Stage II Grade 2 Non-Contiguous Follicular Lymphoma; Stage II Grade 3 Non-Contiguous Follicular Lymphoma; Stage II Non-Contiguous Mantle Cell Lymphoma; Stage II Small Lymphocytic Lymphoma; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Recurrent Childhood Anaplastic Large Cell Lymphoma; Recurrent Childhood Large Cell Lymphoma; Recurrent Childhood Lymphoblastic Lymphoma; Recurrent Childhood Burkitt Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Recurrent Childhood Hodgkin Lymphoma; Recurrent Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Secondary Myelodysplastic Syndrome; Stage I Adult Burkitt Lymphoma; Stage I Adult Diffuse Large Cell Lymphoma; Stage I Adult Diffuse Mixed Cell Lymphoma; Stage I Adult Immunoblastic Lymphoma; Stage I Adult Lymphoblastic Lymphoma; Stage I Childhood Anaplastic Large Cell Lymphoma; Stage I Childhood Large Cell Lymphoma; Stage I Childhood Lymphoblastic Lymphoma; Stage I Childhood Burkitt Lymphoma; Stage I Grade 1 Follicular Lymphoma; Stage I Grade 2 Follicular Lymphoma; Stage I Grade 3 Follicular Lymphoma; Stage I Mantle Cell Lymphoma; Stage I Marginal Zone Lymphoma; Stage I Small Lymphocytic Lymphoma; Stage II Childhood Anaplastic Large Cell Lymphoma; Stage II Childhood Lymphoblastic Lymphoma; Stage II Childhood Burkitt Lymphoma; Stage III Adult Burkitt Lymphoma; Stage III Adult Diffuse Large Cell Lymphoma; Stage III Adult Diffuse Mixed Cell Lymphoma; Stage III Adult Diffuse Small Cleaved Cell Lymphoma; Stage III Adult Immunoblastic Lymphoma; Stage III Adult Lymphoblastic Lymphoma; Stage III Childhood Anaplastic Large Cell Lymphoma; Stage III Childhood Large Cell Lymphoma; Stage III Childhood Lymphoblastic Lymphoma; Stage III Childhood Burkitt Lymphoma; Stage III Grade 1 Follicular Lymphoma; Stage III Grade 2 Follicular Lymphoma; Stage III Grade 3 Follicular Lymphoma; Stage III Mantle Cell Lymphoma; Stage III Marginal Zone Lymphoma; Stage III Small Lymphocytic Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Immunoblastic Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Childhood Anaplastic Large Cell Lymphoma; Stage IV Childhood Large Cell Lymphoma; Stage IV Childhood Lymphoblastic Lymphoma; Stage IV Childhood Burkitt Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Small Lymphocytic Lymphoma

Number of positive preoperative biopsy cores is a predictor of positive surgical margins (PSM) in small prostates after robot-assisted radical prostatectomy (RARP).

PubMed

Tuliao, Patrick H; Koo, Kyo C; Komninos, Christos; Chang, Chien H; Choi, Young D; Chung, Byung H; Hong, Sung J; Rha, Koon H

2015-12-01

To determine the impact of prostate size on positive surgical margin (PSM) rates after robot-assisted radical prostatectomy (RARP) and the preoperative factors associated with PSM. In all, 1229 men underwent RARP by a single surgeon, from 2005 to August of 2013. Excluded were patients who had transurethral resection of the prostate, neoadjuvant therapy, clinically advanced cancer, and the first 200 performed cases (to reduce the effect of learning curve). Included were 815 patients who were then divided into three prostate size groups: <31 g (group 1), 31-45 g (group 2), >45 g (group 3). Multivariate analysis determined predictors of PSM and biochemical recurrence (BCR). Console time and blood loss increased with increasing prostate size. There were more high-grade tumours in group 1 (group 1 vs group 2 and group 3, 33.9% vs 25.1% and 25.6%, P = 0.003 and P = 0.005). PSM rates were higher in prostates of <45 g with preoperative PSA levels of >20 ng/dL, Gleason score ≥7, T3 tumour, and ≥3 positive biopsy cores. In group 1, preoperative stage T3 [odds ratio (OR) 3.94, P = 0.020] and ≥3 positive biopsy cores (OR 2.52, P = 0.043) were predictive of PSM, while a PSA level of >20 ng/dL predicted the occurrence of BCR (OR 5.34, P = 0.021). No preoperative factors predicted PSM or BCR for groups 2 and 3. A preoperative biopsy with ≥3 positive cores in men with small prostates predicts PSM after RARP. In small prostates with PSM, a PSA level of >20 ng/dL is a predictor of BCR. These factors should guide the choice of therapy and indicate the need for closer postoperative follow-up. © 2014 The Authors BJU International © 2014 BJU International Published by John Wiley & Sons Ltd.

In Vitro Synthesized RNA Generated from cDNA Clones of Both Genomic Components of Cucurbit yellow stunting disorder virus Replicates in Cucumber Protoplasts

PubMed Central

Owen, Carolyn A.; Moukarzel, Romy; Huang, Xiao; Kassem, Mona A.; Eliasco, Eleonora; Aranda, Miguel A.; Coutts, Robert H. A.; Livieratos, Ioannis C.

2016-01-01

Cucurbit yellow stunting disorder virus (CYSDV), a bipartite whitefly-transmitted virus, constitutes a major threat to commercial cucurbit production worldwide. Here, construction of full-length CYSDV RNA1 and RNA2 cDNA clones allowed the in vitro synthesis of RNA transcripts able to replicate in cucumber protoplasts. CYSDV RNA1 proved competent for replication; transcription of both polarities of the genomic RNA was detectable 24 h post inoculation. Hybridization of total RNA extracted from transfected protoplasts or from naturally CYSDV-infected cucurbits revealed high-level transcription of the p22 subgenomic RNA species. Replication of CYSDV RNA2 following co-transfection with RNA1 was also observed, with similar transcription kinetics. A CYSDV RNA2 cDNA clone (T3CM8Δ) comprising the 5′- and 3′-UTRs plus the 3′-terminal gene, generated a 2.8 kb RNA able to replicate to high levels in protoplasts in the presence of CYSDV RNA1. The clone T3CM8Δ will facilitate reverse genetics studies of CYSDV gene function and RNA replication determinants. PMID:27314380

c-Abl phosphorylation of Yin Yang 1's conserved tyrosine 254 in the spacer region modulates its transcriptional activity.

PubMed

Daraiseh, Susan I; Kassardjian, Ari; Alexander, Karen E; Rizkallah, Raed; Hurt, Myra M

2018-05-25

Yin Yang 1 (YY1) is a multifunctional transcription factor that can activate or repress transcription depending on the promotor and/or the co-factors recruited. YY1 is phosphorylated in various signaling pathways and is critical for different biological functions including embryogenesis, apoptosis, proliferation, cell-cycle regulation and tumorigenesis. Here we report that YY1 is a substrate for c-Abl kinase phosphorylation at conserved residue Y254 in the spacer region. Pharmacological inhibition of c-Abl kinase by imatinib, nilotinib and GZD824, knock-down of c-Abl using siRNA, and the use of c-Abl kinase-dead drastically reduces tyrosine phosphorylation of YY1. Both radioactive and non-radioactive in vitro kinase assays, as well as co-immunoprecipitation in different cell lines, show that the target of c-Abl phosphorylation is tyrosine residue 254. c-Abl phosphorylation has little effect on YY1 DNA binding ability or cellular localization in asynchronous cells. However, functional studies reveal that c-Abl mediated phosphorylation of YY1 regulates YY1's transcriptional ability in vivo. In conclusion, we demonstrate the novel role of c-Abl kinase in regulation of YY1's transcriptional activity, linking YY1 regulation with c-Abl tyrosine kinase signaling pathways. Copyright © 2018. Published by Elsevier B.V.

Peptide nucleic acid probe-based fluorescence melting curve analysis for rapid screening of common JAK2, MPL, and CALR mutations.

PubMed

Park, Joonhong; Song, Minsik; Jang, Woori; Chae, Hyojin; Lee, Gun Dong; Kim, KyungTak; Park, Heekyung; Kim, Myungshin; Kim, Yonggoo

2017-02-01

We developed and evaluated the feasibility of peptide nucleic acid (PNA)-based fluorescence melting curve analysis (FMCA) to detect common mutations in myeloproliferative neoplasms (MPNs). We have set up two separate reactions of PNA-based FMCA: JAK2 V617F &CALR p.Leu367fs*46 (set A) and MPL W515L/K &CALR p.Lys385fs*47 (set B). Clinical usefulness was validated with allele-specific real-time PCR, fragment analysis, Sanger sequencing in 57 BCR-ABL1-negative MPNs. The limit of detection (LOD) of PNA-based FMCA was approximately 10% for each mutation and interference reactions using mixtures of different mutations were not observed. Non-specific amplification was not observed in normal control. PNA-based FMCA was able to detect all JAK2 V617F (n=20), CALR p.Leu367fs*46 (n=10) and p.Lys385fs*47 (n=8). Three of six MPL mutations were detected except three samples with low mutant concentration in out of LOD. JAK2 exon 12 mutations (n=7) were negative without influencing V617F results. Among six variant CALR exon 9 mutations, two were detected by this method owing to invading of probe binding site. PNA-based FMCA for detecting common JAK2, MPL, and CALR mutations is a rapid, simple, and sensitive technique in BCR-ABL1-negative MPNs with >10% mutant allele at the time of initial diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

c-Abl kinase inhibitors overcome CD40-mediated drug resistance in CLL: implications for therapeutic targeting of chemoresistant niches.

PubMed

Hallaert, Delfine Y H; Jaspers, Annelieke; van Noesel, Carel J; van Oers, Marinus H J; Kater, Arnon P; Eldering, Eric

2008-12-15

In lymph node (LN) proliferation centers in chronic lymphocytic leukemia (CLL), the environment protects from apoptotic and cytotoxic triggers. Here, we aimed to define the molecular basis for the increased drug resistance and searched for novel strategies to circumvent it. The situation in CLL LN could be mimicked by prolonged in vitro CD40 stimulation, which resulted in up-regulation of antiapoptotic Bcl-xL, A1/Bfl-1, and Mcl-1 proteins, and afforded resistance to various classes of drugs (fludarabine, bortezomib, roscovitine). CD40 stimulation also caused ERK-dependent reduction of Bim-EL protein, but ERK inhibition did not prevent drug resistance. Drugs combined with sublethal doses of the BH3-mimetic ABT-737 displayed partial and variable effects per individual CD40-stimulated CLL. The antiapoptotic profile of CD40-triggered CLL resembled BCR-Abl-dependent changes seen in chronic myeloid leukemia (CML), which prompted application of c-Abl inhibitors imatinib or dasatinib. Both compounds, but especially dasatinib, prevented the entire antiapoptotic CD40 program in CLL cells, and restored drug sensitivity. These effects also occurred in CLL samples with dysfunctional p53. Importantly, ex vivo CLL LN samples also displayed strong ERK activation together with high Bcl-xL and Mcl-1 but low Bim levels. These data indicate that CLL cells in chemoresistant niches may be sensitive to therapeutic strategies that include c-Abl inhibitors.

The Zinc-finger protein ASCIZ regulates B cell development via DYNLL1 and Bim

PubMed Central

Jurado, Sabine; Gleeson, Kimberly; O’Donnell, Kristy; Izon, David J.; Walkley, Carl R.; Strasser, Andreas; Tarlinton, David M.

2012-01-01

Developing B lymphocytes expressing defective or autoreactive pre-B or B cell receptors (BCRs) are eliminated by programmed cell death, but how the balance between death and survival signals is regulated to prevent immunodeficiency and autoimmunity remains incompletely understood. In this study, we show that absence of the essential ATM (ataxia telangiectasia mutated) substrate Chk2-interacting Zn2+-finger protein (ASCIZ; also known as ATMIN/ZNF822), a protein with dual functions in the DNA damage response and as a transcription factor, leads to progressive cell loss from the pre-B stage onwards and severely diminished splenic B cell numbers in mice. This lymphopenia cannot be suppressed by deletion of p53 or complementation with a prearranged BCR, indicating that it is not caused by impaired DNA damage responses or defective V(D)J recombination. Instead, ASCIZ-deficient B cell precursors contain highly reduced levels of DYNLL1 (dynein light chain 1; LC8), a recently identified transcriptional target of ASCIZ, and normal B cell development can be restored by ectopic Dynll1 expression. Remarkably, the B cell lymphopenia in the absence of ASCIZ can also be fully suppressed by deletion of the proapoptotic DYNLL1 target Bim. Our findings demonstrate a key role for ASCIZ in regulating the survival of developing B cells by activating DYNLL1 expression, which may then modulate Bim-dependent apoptosis. PMID:22891272

Functional interaction between nonreceptor tyrosine kinase c-Abl and SR-Rich protein RBM39

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mai, Sanyue; Qu, Xiuhua; Li, Ping

RBM39, also known as splicing factor HCC1.4, acts as a transcriptional coactivator for the steroid nuclear receptors JUN/AP-1, ESR1/ER-α and ESR2/ER-β. RBM39 is involved in the regulation of the transcriptional responses of these steroid nuclear receptors and promotes transcriptional initiation. In this paper, we report that RBM39 interacts with the nonreceptor tyrosine kinase c-Abl. Both the Src homology (SH) 2 and SH3 domains of c-Abl interact with RBM39. The major tyrosine phosphorylation sites on RBM39 that are phosphorylated by c-Abl are Y95 and Y99, as demonstrated by liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) and mutational analysis. c-Abl wasmore » shown boost the transcriptional coactivation activity of RBM39 for ERα and PRβ in a tyrosine kinase-dependent manner. The results suggest that mammalian c-Abl plays an important role in steroid hormone receptor-mediated transcription by regulating RBM39. - Highlights: • c-Abl interacts with RBM39. • RBM39 is phosphorylated by c-Abl. • c-Abl regulates transcriptional coactivation activity of RBM39 on the ERα and PRβ.« less

DNA methylation screening of primary prostate tumors identifies SRD5A2 and CYP11A1 as candidate markers for assessing risk of biochemical recurrence.

PubMed

Horning, Aaron M; Awe, Julius A; Wang, Chiou-Miin; Liu, Joseph; Lai, Zhao; Wang, Vickie Yao; Jadhav, Rohit R; Louie, Anna D; Lin, Chun-Lin; Kroczak, Tad; Chen, Yidong; Jin, Victor X; Abboud-Werner, Sherry L; Leach, Robin J; Hernandez, Javior; Thompson, Ian M; Saranchuk, Jeff; Drachenberg, Darrel; Chen, Chun-Liang; Mai, Sabine; Huang, Tim Hui-Ming

2015-11-01

Altered DNA methylation in CpG islands of gene promoters has been implicated in prostate cancer (PCa) progression and can be used to predict disease outcome. In this study, we determine whether methylation changes of androgen biosynthesis pathway (ABP)-related genes in patients' plasma cell-free DNA (cfDNA) can serve as prognostic markers for biochemical recurrence (BCR). Methyl-binding domain capture sequencing (MBDCap-seq) was used to identify differentially methylated regions (DMRs) in primary tumors of patients who subsequently developed BCR or not, respectively. Methylation pyrosequencing of candidate loci was validated in cfDNA samples of 86 PCa patients taken at and/or post-radical prostatectomy (RP) using univariate and multivariate prediction analyses. Putative DMRs in 13 of 30 ABP-related genes were found between tumors of BCR (n = 12) versus no evidence of disease (NED) (n = 15). In silico analysis of The Cancer Genome Atlas data confirmed increased DNA methylation of two loci-SRD5A2 and CYP11A1, which also correlated with their decreased expression, in tumors with subsequent BCR development. Their aberrant cfDNA methylation was also associated with detectable levels of PSA taken after patients' post-RP. Multivariate analysis of the change in cfDNA methylation at all of CpG sites measured along with patient's treatment history predicted if a patient will develop BCR with 77.5% overall accuracy. Overall, increased DNA methylation of SRD5A2 and CYP11A1 related to androgen biosynthesis functions may play a role in BCR after patients' RP. The correlation between aberrant cfDNA methylation and detectable PSA in post-RP further suggests their utility as predictive markers for PCa recurrence. . © 2015 Wiley Periodicals, Inc.

Identification of a new gene regulatory circuit involving B cell receptor activated signaling using a combined analysis of experimental, clinical and global gene expression data

PubMed Central

Schrader, Alexandra; Meyer, Katharina; Walther, Neele; Stolz, Ailine; Feist, Maren; Hand, Elisabeth; von Bonin, Frederike; Evers, Maurits; Kohler, Christian; Shirneshan, Katayoon; Vockerodt, Martina; Klapper, Wolfram; Szczepanowski, Monika; Murray, Paul G.; Bastians, Holger; Trümper, Lorenz; Spang, Rainer; Kube, Dieter

2016-01-01

To discover new regulatory pathways in B lymphoma cells, we performed a combined analysis of experimental, clinical and global gene expression data. We identified a specific cluster of genes that was coherently expressed in primary lymphoma samples and suppressed by activation of the B cell receptor (BCR) through αIgM treatment of lymphoma cells in vitro. This gene cluster, which we called BCR.1, includes numerous cell cycle regulators. A reduced expression of BCR.1 genes after BCR activation was observed in different cell lines and also in CD10+ germinal center B cells. We found that BCR activation led to a delayed entry to and progression of mitosis and defects in metaphase. Cytogenetic changes were detected upon long-term αIgM treatment. Furthermore, an inverse correlation of BCR.1 genes with c-Myc co-regulated genes in distinct groups of lymphoma patients was observed. Finally, we showed that the BCR.1 index discriminates activated B cell-like and germinal centre B cell-like diffuse large B cell lymphoma supporting the functional relevance of this new regulatory circuit and the power of guided clustering for biomarker discovery. PMID:27166259

High Dose Cyclophosphamide, Tacrolimus, and Mycophenolate Mofetil in Preventing Graft Versus Host Disease in Patients With Hematological Malignancies Undergoing Myeloablative or Reduced Intensity Donor Stem Cell Transplant

ClinicalTrials.gov

2018-01-24

Acute Leukemia; Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Diffuse Large B-Cell Lymphoma; Follicular Lymphoma; Graft Versus Host Disease; Hodgkin Lymphoma; Mantle Cell Lymphoma; Marginal Zone Lymphoma; Myelodysplastic Syndrome; Myeloproliferative Neoplasm; Recurrent Acute Myeloid Leukemia With Myelodysplasia-Related Changes; Recurrent Plasma Cell Myeloma; Refractory Plasma Cell Myeloma; Secondary Myelodysplastic Syndrome

Structural Analysis of DFG-in and DFG-out Dual Src-Abl Inhibitors Sharing a Common Vinyl Purine Template

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Tianjun; Commodore, Lois; Huang, Wei-Sheng

2010-09-30

Bcr-Abl is the oncogenic protein tyrosine kinase responsible for chronic myeloid leukemia (CML). Treatment of the disease with imatinib (Gleevec) often results in drug resistance via kinase mutations at the advanced phases of the disease, which has necessitated the development of new mutation-resistant inhibitors, notably against the T315I gatekeeper mutation. As part of our efforts to discover such mutation resistant Abl inhibitors, we have focused on optimizing purine template kinase inhibitors, leading to the discovery of potent DFG-in and DFG-out series of Abl inhibitors that are also potent Src inhibitors. Here we present crystal structures of Abl bound by twomore » such inhibitors, based on a common N9-arenyl purine, and that represent both DFG-in and -out binding modes. In each structure the purine template is bound deeply in the adenine pocket and the novel vinyl linker forms a non-classical hydrogen bond to the gatekeeper residue, Thr315. Specific template substitutions promote either a DFG-in or -out binding mode, with the kinase binding site adjusting to optimize molecular recognition. Bcr-Abl T315I mutant kinase is resistant to all currently marketed Abl inhibitors, and is the focus of intense drug discovery efforts. Notably, our DFG-out inhibitor, AP24163, exhibits modest activity against this mutant, illustrating that this kinase mutant can be inhibited by DFG-out class inhibitors. Furthermore our DFG-out inhibitor exhibits dual Src-Abl activity, absent from the prototypical DFG-out inhibitor, imatinib as well as its analog, nilotinib. The data presented here provides structural guidance for the further design of novel potent DFG-out class inhibitors against Src, Abl and Abl T315I mutant kinases.« less

Part-1: Design, synthesis and biological evaluation of novel bromo-pyrimidine analogs as tyrosine kinase inhibitors.

PubMed

Munikrishnappa, Chandrashekar Suradhenupura; Puranik, Sangamesh B; Kumar, G V Suresh; Prasad, Y Rajendra

2016-08-25

A novel series of 5-bromo-pyrimidine derivatives (5a-l, 6a-h, 9a-m and 10a-d) were synthesized through multi step reactions starting from 5-bromo-2,4-dichloro pyrimidine. The newly synthesized compounds were characterized using elemental analysis and spectral data (IR, (1)H NMR, (13)C NMR and LC-MS) analysis. The titled compounds were evaluated for their in vitro cytotoxic activity against tumor cell lines panel consisted of HCT116 (human colon cancer cell line), A549 (human lung cancer cell line), K562 (human chronic myeloid leukemia cell line), U937 (human acute monocytic myeloid leukemia cell line), and L02 (human normal cell line) by using MTT assay Mosmann's method. As most of the compounds are highly potent against K562 cells, all the synthesized compounds were evaluated for Bcr/Abl tyrosine kinase inhibitory activity by using well-established ADP-Glo assay method. Dasatinib was utilized as positive control to validate in both biological evaluations. The biological activity revealed that the compounds 5c, 5e, 6g, 9e, 9f and 10c were potent Bcr/Abl kinase inhibitors among the titled compounds. Thus these compounds may be promising lead compounds to be developed as an alternative for current Dasatinib therapy. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

CD22 Promotes B-1b Cell Responses to T Cell-Independent Type 2 Antigens.

PubMed

Haas, Karen M; Johnson, Kristen L; Phipps, James P; Do, Cardinal

2018-03-01

CD22 (Siglec-2) is a critical regulator of B cell activation and survival. CD22 -/- mice generate significantly impaired Ab responses to T cell-independent type 2 (TI-2) Ags, including haptenated Ficoll and pneumococcal polysaccharides, Ags that elicit poor T cell help and activate BCR signaling via multivalent epitope crosslinking. This has been proposed to be due to impaired marginal zone (MZ) B cell development/maintenance in CD22 -/- mice. However, mice expressing a mutant form of CD22 unable to bind sialic acid ligands generated normal TI-2 Ab responses, despite significantly reduced MZ B cells. Moreover, mice treated with CD22 ligand-binding blocking mAbs, which deplete MZ B cells, had little effect on TI-2 Ab responses. We therefore investigated the effects of CD22 deficiency on B-1b cells, an innate-like B cell population that plays a key role in TI-2 Ab responses. B-1b cells from CD22 -/- mice had impaired BCR-induced proliferation and significantly increased intracellular Ca 2+ concentration responses following BCR crosslinking. Ag-specific B-1b cell expansion and plasmablast differentiation following TI-2 Ag immunization was significantly impaired in CD22 -/- mice, consistent with reduced TI-2 Ab responses. We generated CD22 -/- mice with reduced CD19 levels (CD22 -/- CD19 +/- ) to test the hypothesis that augmented B-1b cell BCR signaling in CD22 -/- mice contributes to impaired TI-2 Ab responses. BCR-induced proliferation and intracellular Ca 2+ concentration responses were normalized in CD22 -/- CD19 +/- B-1b cells. Consistent with this, TI-2 Ag-specific B-1b cell expansion, plasmablast differentiation, survival, and Ab responses were rescued in CD22 -/- CD19 +/- mice. Thus, CD22 plays a critical role in regulating TI-2 Ab responses through regulating B-1b cell signaling thresholds. Copyright © 2018 by The American Association of Immunologists, Inc.

FLT3-regulated antigens as targets for leukemia-reactive cytotoxic T lymphocytes

PubMed Central

Brackertz, B; Conrad, H; Daniel, J; Kast, B; Krönig, H; Busch, D H; Adamski, J; Peschel, C; Bernhard, H

2011-01-01

The FMS-like tyrosine kinase 3 (FLT3) is highly expressed in acute myeloid leukemia (AML). Internal tandem duplications (ITD) of the juxtamembrane domain lead to the constitutive activation of the FLT3 kinase inducing the activation of multiple genes, which may result in the expression of leukemia-associated antigens (LAAs). We analyzed the regulation of LAA in FLT3-wild-type (WT)- and FLT3-ITD+ myeloid cells to identify potential targets for antigen-specific immunotherapy for AML patients. Antigens, such as PR-3, RHAMM, Survivin, WT-1 and PRAME, were upregulated by constitutively active FLT3-ITD as well as FLT3-WT activated by FLT3 ligand (FL). Cytotoxic T-cell (CTL) clones against PR-3, RHAMM, Survivin and an AML-directed CTL clone recognized AML cell lines and primary AML blasts expressing FLT3-ITD, as well as FLT3-WT+ myeloid dendritic cells in the presence of FL. Downregulation of FLT3 led to the abolishment of CTL recognition. Comparing our findings concerning LAA upregulation by the FLT3 kinase with those already made for the Bcr-Abl kinase, we found analogies in the LAA expression pattern. Antigens upregulated by both FLT3 and Bcr-Abl may be promising targets for the development of immunotherapeutical approaches against myeloid leukemia of different origin. PMID:22829124

Open Label, Phase II Study to Evaluate Efficacy and Safety of Oral Nilotinib in Philadelphia Positive (Ph+) Chronic Myelogenous Leukemia (CML) Pediatric Patients.

ClinicalTrials.gov

2018-04-20

Leukemia; Leukemia,Pediatric; Leukemia, Myleiod; Leukemia, Mylegenous, Chronic; Leukemia, Mylegenous, Accelerated; BCR-ABL Positive; Myeloproliferative Disorder; Bone Marrow Disease; Hematologic Diseases; Neoplastic Processes; Imatinib; Dasatinib; Enzyme Inhibitor; Protein Kinase Inhibitor

Glivec and CML: a lucky date.

PubMed

Saglio, G; Cilloni, D; Rancati, F; Boano, L

2004-01-01

Chronic Myeloid Leukemia (CML) has always been an ideal model to understand the molecular pathogenesis of human leukaemias and the way to cure them. This can be ascribed to the fact that CML was the first human cancer demonstrated to be strongly associated to the presence of a recurrent chromosomal translocation (the t(9;22)(q34;q11) that creates the Philadelphia (Ph)-chromosome) and to a specific molecular defect, the formation of a hybrid BCR-ABL gene that generates new fusion proteins endowed with a constitutive tyrosine-kinase (TK) activity, strongly implicated in the pathogenesis of the disease. The introduction into clinical practice of imatinib, (Glivec, Gleevec, Novartis), a potent tyrosine kinase inhibitor of the Bcr-Abl protein as well as of a restricted number of other TKs, has not only produced a substantial improvement in the treatment of CML, but represents a major break-through in the perspective of opening a new era, that of molecularly targeted therapy, in the management of other types of leukemia, lymphoma and cancer in general.

Analogs, formulations and derivatives of imatinib: a patent review.

PubMed

Musumeci, Francesca; Schenone, Silvia; Grossi, Giancarlo; Brullo, Chiara; Sanna, Monica

2015-01-01

The Bcr-Abl inhibitor imatinib was approved in 2001 for chronic myeloid leukemia therapy, and dramatically changed the lives of patients affected by this disease. Since it also inhibits platelet derived growth factor receptor (PDGFR) and c-Kit, imatinib is used for various other tumors caused by abnormalities of one or both these two enzymes. This review presents an overview on imatinib formulations and derivatives, synthetic methodologies and therapeutic uses that have appeared in the patent literature since 2008. Innovative imatinib formulations, such as nanoparticles containing the drug, will improve its bioavailability. Moreover, oral solutions or high imatinib content tablets or capsules will improve patient compliance. Some solid formulations and innovative syntheses that have appeared in the last few years will reduce the cost of the drug, offering big advantages for poor countries. Some recently patented efficacious imatinib derivatives are in preclinical studies and could enter clinical trials in the next few years. Overall, Bcr-Abl inhibitors constitute a very appealing research field that can be expected to expand further.

SRD5A polymorphisms and biochemical failure after radical prostatectomy.

PubMed

Audet-Walsh, Etienne; Bellemare, Judith; Nadeau, Geneviève; Lacombe, Louis; Fradet, Yves; Fradet, Vincent; Huang, Shu-Pin; Bao, Bo-Ying; Douville, Pierre; Girard, Hugo; Guillemette, Chantal; Lévesque, Eric

2011-12-01

The relationship between inherited germ-line variations in the 5α-reductase pathways of androgen biosynthesis and the risk of biochemical recurrence (BCR) after radical prostatectomy (RP) remains an unexplored area. To determine the link between germ-line variations in the steroid-5α-reductase, α-polypeptide 1 (SRD5A1) and steroid-5α-reductase, α-polypeptide 2 (SRD5A2) genes and BCR. We studied retrospectively two independent cohorts composed of 526 white (25% BCR) and 320 Asian men (36% BCR) with pathologically organ-confined prostate cancer who had a median follow-up of 88.8 and 30.8 mo after surgery, respectively. Patients were genotyped for 19 haplotype-tagging single nucleotide polymorphisms (htSNPs) in SRD5A1 and SRD5A2 genes, and their prognostic significance on prostate-specific antigen recurrence was assessed using Kaplan-Meier analysis and the Cox regression model. After adjusting for all clinicopathologic risk factors, four SNPs (rs2208532, rs12470143, rs523349, and rs4952197) were associated with BCR in both whites and Asians. The strongest effect was conferred by the SRD5A2 V89L nonsynonymous SNP (rs523349C) with a hazard ratio (HR) of 2.87 (95% confidence interval [CI], 2.07-4.00; p = 4 × 10⁻¹⁰; 48% BCR). In addition, in whites, the combination of two SNPs, rs518673T in SRD5A1 and rs12470143A in SRD5A2, was associated with a reduced BCR rate for carriers of three or four alleles (HR: 0.37; 95% CI, 0.19-0.71; p=0.003;16% BCR) compared with noncarriers (38% BCR), whereas the SRD5A2 rs12470143A was significant in Asians (HR: 0.46; 95% CI, 0.28-0.73; p=0.001). Limitations of our study include few events of androgen-deprivation resistance or cancer-specific death. Our study is the first to show positive associations of several SRD5A1 and SRD5A2 variations as independent predictors of BCR after RP. Copyright © 2011 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Engagement of CD22 on B cells with the monoclonal antibody epratuzumab stimulates the phosphorylation of upstream inhibitory signals of the B cell receptor.

PubMed

Lumb, Simon; Fleischer, Sarah J; Wiedemann, Annika; Daridon, Capucine; Maloney, Alison; Shock, Anthony; Dörner, Thomas

2016-06-01

The binding of antigen to the B cell receptor (BCR) results in a cascade of signalling events that ultimately drive B cell activation. Uncontrolled B cell activation is regulated by negative feedback loops that involve inhibitory co-receptors such as CD22 and CD32B that exert their functions following phosphorylation of immunoreceptor tyrosine-based inhibition motifs (ITIMs). The CD22-targeted antibody epratuzumab has previously been shown to inhibit BCR-driven signalling events, but its effects on ITIM phosphorylation of CD22 and CD32B have not been properly evaluated. The present study therefore employed both immunoprecipitation and flow cytometry approaches to elucidate the effects of epratuzumab on direct phosphorylation of key tyrosine (Tyr) residues on both these proteins, using both transformed B cell lines and primary human B cells. Epratuzumab induced the phosphorylation of Tyr(822) on CD22 and enhanced its co-localisation with SHP-1. Additionally, in spite of high basal phosphorylation of other key ITIMs on CD22, in primary human B cells epratuzumab also enhanced phosphorylation of Tyr(807), a residue involved in the recruitment of Grb2. Such initiation events could explain the effects of epratuzumab on downstream signalling in B cells. Finally, we were able to demonstrate that epratuzumab stimulated the phosphorylation of Tyr(292) on the low affinity inhibitory Fc receptor CD32B which would further attenuate BCR-induced signalling. Together, these data demonstrate that engagement of CD22 with epratuzumab leads to the direct phosphorylation of key upstream inhibitory receptors of BCR signalling and may help to explain how this antibody modulates B cell function.

Adverse pathology and undetectable ultrasensitive prostate-specific antigen after radical prostatectomy: is adjuvant radiation warranted?

PubMed

Simon, Ross M; Howard, Lauren E; Freedland, Stephen J; Aronson, William J; Terris, Martha K; Kane, Christopher J; Amling, Christopher L; Cooperberg, Matthew R; Vidal, Adriana C

2016-06-01

To determine if men with adverse pathology but undetectable ultrasensitive (<0.01 ng/mL) PSA are at high-risk for biochemical recurrence (BCR), or if there is a subset of patients at low-risk for whom the benefit of adjuvant radiation therapy might be limited. We evaluated 411 patients treated with RP from 2001 to 2013 without adjuvant radiation who had an undetectable (<0.01 ng/mL) PSA level after RP but with adverse pathology [positive surgical margins (PSMs), extraprostatic extension (EPE), and/or seminal vesicle invasion (SVI)]. Multivariable Cox regression analyses tested the relationship between pathological characteristics and BCR to identify groups of men at highest risk of early BCR. On multivariable analysis, only pathological Gleason 7 (4 + 3), Gleason ≥8, and SVI independently predicted BCR (P = 0.019, P < 0.001, and P = 0.001, respectively), although on two-way analysis men with Gleason 7 (4 + 3) did not have significantly higher rates of BCR compared with patients with Gleason ≤6 (log-rank, P = 0.074). Men with either Gleason ≥8 (with PSMs or EPE) or SVI (15% of the cohort) defined a high-risk group vs men without these characteristics (3-year BCR risk of 50.4% vs 11.9%, log-rank, P < 0.001). Among men with adverse pathology but an undetectable (<0.01 ng/mL) PSA level after RP, the benefits of adjuvant radiation are probably limited except for men with Gleason 8-10 (with PSMs or EPE) or SVI who are at high-risk of early BCR. © 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.

Cytogenetic and molecular characterization of double inversion 3 associated with a cryptic BCR-ABL1 rearrangement and additional genetic changes.

PubMed

Toydemir, Reha; Rowe, Leslie; Hibbard, Michele; Salama, Mohamed; Shetty, Shashirekha

2010-09-01

Rearrangements of chromosome 3 involving bands 3q21 and 3q26 have been reported in about 2% of patients with acute myeloid leukemia, and rarely in myelodysplastic syndrome or chronic myelogenous leukemia (CML). To date, only six cases of inversion of both homologues have been reported. Loss of normal chromosome 3 and duplication of the inverted chromosome have been proposed as the most likely mechanism, but have not been shown experimentally. We present a 36-year-old male with an initial diagnosis of CML and resistance to imatinib mesylate. Chromosome analysis showed an inversion within the long arm of both homologues of chromosome 3 and an interstitial deletion within the long arm of one chromosome 7. The rearrangement of EVI1 locus on both homologues of chromosome 3 was confirmed by fluorescence in situ hybridization (FISH). Additional FISH studies showed a cryptic insertion of ABL1 into the BCR region, and subsequent duplication of the derivative chromosome 22. The single-nucleotide polymorphism array showed copy-neutral loss of heterozygosity on chromosomes 3 and 22, suggesting that a somatic repair mechanism is involved in the evolution of these genetic alterations. This case illustrates the complexity of genetic aberrations in neoplastic cells, and the value of array technology, used in concert with conventional cytogenetic methods, for a better understanding of the pathogenesis. 2010 Elsevier Inc. All rights reserved.

The mTORC1-Signaling Pathway and Hepatic Polyribosome Profile Are Enhanced after the Recovery of a Protein Restricted Diet by a Combination of Soy or Black Bean with Corn Protein.

PubMed

Márquez-Mota, Claudia C; Rodriguez-Gaytan, Cinthya; Adjibade, Pauline; Mazroui, Rachid; Gálvez, Amanda; Granados, Omar; Tovar, Armando R; Torres, Nimbe

2016-09-20

Between 6% and 11% of the world's population suffers from malnutrition or undernutrition associated with poverty, aging or long-term hospitalization. The present work examined the effect of different types of proteins on the mechanistic target of rapamycin (mTORC1)-signaling pathway in: (1) healthy; and (2) protein restricted rats. (1) In total, 200 rats were divided into eight groups and fed one of the following diets: 20% casein (C), soy (S), black bean (B), B + Corn (BCr), Pea (P), spirulina (Sp), sesame (Se) or Corn (Cr). Rats fed C or BCr had the highest body weight gain; rats fed BCr had the highest pS6K1/S6K1 ratio; rats fed B, BCr or P had the highest eIF4G expression; (2) In total, 84 rats were fed 0.5% C for 21 day and protein rehabilitated with different proteins. The S, soy + Corn (SCr) and BCr groups had the highest body weight gain. Rats fed SCr and BCr had the highest eIF4G expression and liver polysome formation. These findings suggest that the quality of the dietary proteins modulate the mTORC1-signaling pathway. In conclusion, the combination of BCr or SCr are the best proteins for dietary protein rehabilitation due to the significant increase in body weight, activation of the mTORC1-signaling pathway in liver and muscle, and liver polysome formation.

The mTORC1-Signaling Pathway and Hepatic Polyribosome Profile Are Enhanced after the Recovery of a Protein Restricted Diet by a Combination of Soy or Black Bean with Corn Protein

PubMed Central

Márquez-Mota, Claudia C.; Rodriguez-Gaytan, Cinthya; Adjibade, Pauline; Mazroui, Rachid; Gálvez, Amanda; Granados, Omar; Tovar, Armando R.; Torres, Nimbe

2016-01-01

Between 6% and 11% of the world’s population suffers from malnutrition or undernutrition associated with poverty, aging or long-term hospitalization. The present work examined the effect of different types of proteins on the mechanistic target of rapamycin (mTORC1)-signaling pathway in: (1) healthy; and (2) protein restricted rats. (1) In total, 200 rats were divided into eight groups and fed one of the following diets: 20% casein (C), soy (S), black bean (B), B + Corn (BCr), Pea (P), spirulina (Sp), sesame (Se) or Corn (Cr). Rats fed C or BCr had the highest body weight gain; rats fed BCr had the highest pS6K1/S6K1 ratio; rats fed B, BCr or P had the highest eIF4G expression; (2) In total, 84 rats were fed 0.5% C for 21 day and protein rehabilitated with different proteins. The S, soy + Corn (SCr) and BCr groups had the highest body weight gain. Rats fed SCr and BCr had the highest eIF4G expression and liver polysome formation. These findings suggest that the quality of the dietary proteins modulate the mTORC1-signaling pathway. In conclusion, the combination of BCr or SCr are the best proteins for dietary protein rehabilitation due to the significant increase in body weight, activation of the mTORC1-signaling pathway in liver and muscle, and liver polysome formation. PMID:27657118

Agent Orange and long-term outcomes after radical prostatectomy.

PubMed

Ovadia, Aaron E; Terris, Martha K; Aronson, William J; Kane, Christopher J; Amling, Christopher L; Cooperberg, Matthew R; Freedland, Stephen J; Abern, Michael R

2015-07-01

To investigate the association between Agent Orange (AO) exposure and long-term prostate cancer (PC) outcomes. Data from 1,882 men undergoing radical prostatectomy for PC between 1988 and 2011 at Veterans Affairs Health Care Facilities were analyzed from the Shared Equal Access Regional Cancer Hospital database. Men were stratified by AO exposure (binary). Associations between AO exposure and biopsy and pathologic Gleason sum (GS) and pathologic stage were determined by logistic regression models adjusted for preoperative characteristics. Hazard ratios for biochemical recurrence (BCR), secondary treatment, metastases, and PC-specific mortality were determined by Cox models adjusted for preoperative characteristics. There were 333 (17.7%) men with AO exposure. AO-exposed men were younger (median 59 vs. 62 y), had lower preoperative prostate-specific antigen levels (5.8 vs. 6.7 ng/ml), lower clinical category (25% vs. 38% palpable), and higher body mass index (28.2 vs. 27.6 kg/m(2)), all P<0.01. Biopsy GS, pathologic GS, positive surgical margins, lymph node positivity, and extracapsular extension did not differ with AO exposure. At a median follow-up of 85 months, 702 (37.4%) patients had BCR, 603 (32.2%) patients received secondary treatment, 78 (4.1%) had metastases, and 39 (2.1%) died of PC. On multivariable analysis, AO exposure was not associated with BCR, secondary treatment, metastases, or PC mortality. AO exposure was not associated with worse preoperative characteristics such as elevated prostate-specific antigen levels or biopsy GS nor with BCR, secondary treatment, metastases, or PC death. Thus, as data on AO-exposed men mature, possible differences in PC outcomes observed previously are no longer apparent. Copyright © 2015 Elsevier Inc. All rights reserved.

Nilotinib and Imatinib Mesylate After Donor Stem Cell Transplant in Treating Patients With ALL or CML

ClinicalTrials.gov

2017-07-11

Accelerated Phase Chronic Myelogenous Leukemia; Adult Acute Lymphoblastic Leukemia in Remission; Blastic Phase Chronic Myelogenous Leukemia; Childhood Acute Lymphoblastic Leukemia in Remission; Childhood Chronic Myelogenous Leukemia; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Chronic Phase Chronic Myelogenous Leukemia; Philadelphia Positive Adult Acute Lymphoblastic Leukemia; Philadelphia Positive Childhood Acute Lymphoblastic Leukemia; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Relapsing Chronic Myelogenous Leukemia; Untreated Adult Acute Lymphoblastic Leukemia; Untreated Childhood Acute Lymphoblastic Leukemia

Graft-Versus-Host Disease Prophylaxis in Treating Patients With Hematologic Malignancies Undergoing Unrelated Donor Peripheral Blood Stem Cell Transplant

ClinicalTrials.gov

2018-02-13

Acute Lymphoblastic Leukemia; Acute Myeloid Leukemia; Aggressive Non-Hodgkin Lymphoma; Chronic Lymphocytic Leukemia; Diffuse Large B-Cell Lymphoma; Hematopoietic and Lymphoid Cell Neoplasm; Indolent Non-Hodgkin Lymphoma; Mantle Cell Lymphoma; Myelodysplastic Syndrome; Myeloproliferative Neoplasm; Prolymphocytic Leukemia; Recurrent Chronic Lymphocytic Leukemia; Recurrent Plasma Cell Myeloma; Refractory Chronic Lymphocytic Leukemia; Refractory Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Refractory Hodgkin Lymphoma; Small Lymphocytic Lymphoma; T-Cell Chronic Lymphocytic Leukemia; Waldenstrom Macroglobulinemia

ON012380: A Non-ATP Competitive Inhibitor of BCR-ABL for the Therapy of Imatinib-Resistant CMLs

DTIC Science & Technology

2009-05-01

viability of peripheral mononuclear cells derived from three normal persons was not affected by either TGAY1 or by Ursolic acid compared to...compounds that are capable of inhibiting this particular (as well as other) amino acid substitution. A major goal of our team was to generate a potent...Fichiner I , Schumacher P, Fiebig HH, Unger C. In vitro and in vivo efficacy of acid -sensitive transferrin and albumin doxorubicin conjugates in a 18

Fludarabine Phosphate, Cyclophosphamide, Total-Body Irradiation, and Donor Bone Marrow Transplant Followed by Donor Natural Killer Cell Therapy, Mycophenolate Mofetil, and Tacrolimus in Treating Patients With Hematologic Cancer

ClinicalTrials.gov

2017-11-08

Acute Lymphoblastic Leukemia; Acute Myeloid Leukemia; Aggressive Non-Hodgkin Lymphoma; Diffuse Large B-Cell Lymphoma; Previously Treated Myelodysplastic Syndrome; Recurrent Chronic Lymphocytic Leukemia; Recurrent Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Recurrent Indolent Adult Non-Hodgkin Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Plasma Cell Myeloma; Recurrent Small Lymphocytic Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Hodgkin Lymphoma; Refractory Plasma Cell Myeloma; Refractory Small Lymphocytic Lymphoma; Waldenstrom Macroglobulinemia

68Ga-PSMA 11 ligand PET imaging in patients with biochemical recurrence after radical prostatectomy - diagnostic performance and impact on therapeutic decision-making.

PubMed

Grubmüller, B; Baltzer, P; D'Andrea, D; Korn, S; Haug, A R; Hacker, M; Grubmüller, K H; Goldner, G M; Wadsak, W; Pfaff, S; Babich, J; Seitz, C; Fajkovic, H; Susani, M; Mazal, P; Kramer, G; Shariat, S F; Hartenbach, Markus

2018-02-01

To evaluate the diagnostic performance of [ 68 Ga]Ga-PSMA HBED-CC conjugate 11 positron emission tomography (PSMA-PET) in the early detection of metastases in patients with biochemical recurrence (BCR) after radical prostatectomy (RP) for clinically non-metastatic prostate cancer, to compare it to CT/MRI alone and to assess its impact on further therapeutic decisions. We retrospectively assessed 117 consecutive hormone-naïve BCR patients who had 68 Ga-PSMA 11 PET/CT (n = 46) or PET/MRI (n = 71) between May 2014 and January 2017. BCR was defined as two PSA rises above 0.2 ng/ml. Two dedicated uro-oncological imaging experts (radiology/nuclear medicine) reviewed separately all images. All results were presented in a blinded sequential fashion to a multidisciplinary tumorboard in order to assess the influence of PSMA-PET imaging on decision-making. The median time from RP to BCR was 36 months (IQR 16-72). Overall, 69 (59%) patients received postoperative radiotherapy. Median PSA level at the time of imaging was 1.04 ng/ml (IQR 0.58-1.87). PSMA-positive lesions were detected in 100 (85.5%) patients. Detection rates were 65% for a PSA value of 0.2 to <0.5 ng/ml, 85.7% for 0.5 to <1, 85.7% for 1 to <2 and 100% for ≥2. PSMA-positive lesions could be confirmed by either histology (16%), PSA decrease in metastasis-directed radiotherapy (45%) or additional information in diffusion-weighted imaging when PET/MRI was performed (18%) in 79% of patients. PSMA-PET detected lesions in 67 patients (57.3%) who had no suspicious correlates according to the RECIST 1.1 criteria on MRI or CT. PSMA-PET changed therapeutic decisions in 74.6% of these 67 patients (p < 0.001), with 86% of them being considered for metastases-directed therapies. We confirm the high performance of PSMA-PET imaging for the detection of disease recurrence sites in patients with BCR after RP, even at relatively low PSA levels. Moreover, it adds significant information to standard CT/MRI, changing treatment strategies in a significant number of patients.

The dual Syk/JAK inhibitor cerdulatinib antagonises B-cell receptor and microenvironmental signaling in chronic lymphocytic leukemia

PubMed Central

Blunt, Matthew D; Koehrer, Stefan; Dobson, Rachel; Larrayoz, Marta; Wilmore, Sarah; Hayman, Alice; Parnell, Jack; Smith, Lindsay; Davies, Andrew; Johnson, Peter W; Conley, Pamela B; Pandey, Anjali; Strefford, Jon C; Stevenson, Freda K; Packham, Graham; Forconi, Francesco; Coffey, Greg; Burger, Jan A; Steele, Andrew J

2017-01-01

Purpose B-cell receptor (BCR)-associated kinase inhibitors such as ibrutinib have revolutionised the treatment of chronic lymphocytic leukemia (CLL). However, these agents are not curative and resistance is already emerging in a proportion of patients. Interleukin-4 (IL-4), expressed in CLL lymph nodes, can augment BCR-signalling and reduce the effectiveness of BCR-kinase inhibitors. Therefore simultaneous targeting of the IL-4- and BCR-signalling pathways by cerdulatinib, a novel dual Syk/JAK inhibitor currently in clinical trials (NCT01994382), may improve treatment responses in patients. Experimental Design PBMCs from CLL patients were treated with cerdulatinib alone or in combination with venetoclax. Cell death, chemokine and cell signalling assay were performed and analysed by flow cytometry, immunoblotting, Q-PCR and ELISA as indicated. Results At concentrations achievable in patients, cerdulatinib inhibited BCR- and IL-4-induced downstream signalling in CLL cells using multiple read-outs and prevented anti-IgM- and nurse-like cell (NLC)-mediated CCL3/CCL4 production. Cerdulatinib induced apoptosis of CLL cells, in a time- and concentration-dependent manner, and particularly in IGHV unmutated samples with greater BCR-signalling capacity and response to IL-4, or samples expressing higher levels of sIgM, CD49d+ or ZAP70+. Cerdulatinib overcame anti-IgM, IL-4/CD40L or NLC-mediated protection by preventing upregulation of MCL-1- and BCL-XL, however BCL-2 expression was unaffected. Furthermore in samples treated with IL-4/CD40L, cerdulatinib synergised with venetoclax in vitro to induce greater apoptosis than either drug alone. Conclusion Cerdulatinib is a promising therapeutic for the treatment of CLL either alone or in combination with venetoclax, with the potential to target critical survival pathways in this currently incurable disease. PMID:27697994

Lymph node yield during radical prostatectomy does not impact rate of biochemical recurrence in patients with seminal vesicle invasion and node-negative disease.

PubMed

Badani, Ketan K; Reddy, Balaji N; Moskowitz, Eric J; Paulucci, David J; Beksac, Alp Tuna; Martini, Alberto; Whalen, Michael J; Skarecky, Douglas W; Huynh, Linda My; Ahlering, Thomas E

2018-06-01

Seminal vesicle invasion (SVI) is a risk factor for poor oncologic outcome in patients with prostate cancer. Modifications to the pelvic lymph node dissection (PLND) during radical prostatectomy (RP) have been reported to have a therapeutic benefit. The present study is the first to determine if lymph node yield (LNY) is associated with a lower risk of biochemical recurrence (BCR) for men with SVI. A total of 220 patients from 2 high-volume institutions who underwent RP without adjuvant treatment between 1990 and 2015 and had prostate cancer with SVI (i.e., pT3b) were identified, and 21 patients did not undergo lymph node dissection. BCR was defined as a postoperative PSA>0.2ng/mL, or use of salvage androgen deprivation therapy (ADT) or radiation. Multivariable Cox proportional hazards models were used to determine whether LNY was predictive of BCR, controlling for PSA, pathologic Gleason Score, pathologic lymph node status, NCCN risk category, etc. The Kaplan-Meier method was used to determine 3-year freedom from BCR. Median number of lymph nodes sampled were 7 (IQR: 3-12; range: 0-35) and 90.5% underwent PLND. The estimated 3-year BCR rate was 43.9%. Results from multivariable analysis demonstrated that LNY was not significantly associated with risk of BCR overall (HR = 1.00, 95% CI: 0.98-1.03; P = 0.848) for pN0 (HR = 0.99, 95% CI: 0.97-1.03; P = 0.916) or pN1 patients (HR = 0.96, 95% CI: 0.88-1.06; P = 0.468). Overall, PSA (HR = 1.02, P<0.001) and biopsy Gleason sum ≥ 8 (HR = 1.81, P = 0.001) were associated with an increased risk of BCR, and increasing LNY increased the likelihood of detecting>2 positive lymph nodes (OR = 1.27, 95% CI: 1.06-1.65, P = 0.023). Seminal vesicle invasion is associated with an increased risk of BCR at 3 years, primarily due to pathologic Gleason score and PSA. Although greater lymph node yield is diagnostic and facilitates more accurate pathologic staging, our data do not show a therapeutic benefit in reducing BCR. Copyright © 2018 Elsevier Inc. All rights reserved.

ATP-Dependent C–F Bond Cleavage Allows the Complete Degradation of 4-Fluoroaromatics without Oxygen

PubMed Central

Tiedt, Oliver; Mergelsberg, Mario; Boll, Kerstin; Müller, Michael; Adrian, Lorenz; Jehmlich, Nico; von Bergen, Martin

2016-01-01

ABSTRACT Complete biodegradation of the abundant and persistent fluoroaromatics requires enzymatic cleavage of an arylic C–F bond, probably the most stable single bond of a biodegradable organic molecule. While in aerobic microorganisms defluorination of fluoroaromatics is initiated by oxygenases, arylic C–F bond cleavage has never been observed in the absence of oxygen. Here, an oxygen-independent enzymatic aryl fluoride bond cleavage is described during the complete degradation of 4-fluorobenzoate or 4-fluorotoluene to CO2 and HF in the denitrifying Thauera aromatica: the ATP-dependent defluorination of 4-fluorobenzoyl-coenzyme A (4-F-BzCoA) to benzoyl-coenzyme A (BzCoA) and HF, catalyzed by class I BzCoA reductase (BCR). Adaptation to growth with the fluoroaromatics was accomplished by the downregulation of a promiscuous benzoate-CoA ligase and the concomitant upregulation of 4-F-BzCoA-defluorinating/dearomatizing BCR on the transcriptional level. We propose an unprecedented mechanism for reductive arylic C–F bond cleavage via a Birch reduction-like mechanism resulting in a formal nucleophilic aromatic substitution. In the proposed anionic 4-fluorodienoyl-CoA transition state, fluoride elimination to BzCoA is favored over protonation to a fluorinated cyclic dienoyl-CoA. PMID:27507824

DEC1/STRA13 is a key negative regulator of activation-induced proliferation of human B cells highly expressed in anergic cells.

PubMed

Camponeschi, Alessandro; Todi, Laura; Cristofoletti, Cristina; Lazzeri, Cristina; Carbonari, Maurizio; Mitrevski, Milica; Marrapodi, Ramona; Del Padre, Martina; Fiorilli, Massimo; Casato, Milvia; Visentini, Marcella

2018-06-01

The transcription factor DEC1/STRA13 (also known as BHLHE40 and SHARP2) is involved in a number of processes including inhibition of cell proliferation and delay of cell cycle, and is a negative regulator of B cell activation and development in mice. We show here that, unlike in mice, DEC1/STRA13 expression is induced in human naïve and memory resting B cells by activation through the B-cell receptor (BCR) or Toll-like receptor 9 (TLR9). siRNA silencing of DEC1/STRA13 increases the capacity of activated B cells to perform a high number of divisions after TLR9 ligation. This identifies DEC1/STRA13 as a critical negative regulator of clonal expansion of activated human B cells. We also show that DEC1/STRA13 is upregulated in human anergic CD21 low B cells clonally expanded in patients with HCV-associated mixed cryoglobulinemia, which fail to proliferate in response to BCR or TLR9 ligation. siRNA knockdown of DEC1/STRA13, however, fails to restore responsiveness to stimuli in these cells, although it might improve the proliferative capacity in a subset of anergic cells with less pronounced proliferative defect. Copyright © 2018 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Early response with dasatinib or imatinib in chronic myeloid leukemia: 3-year follow-up from a randomized phase 3 trial (DASISION)

PubMed Central

Jabbour, Elias; Saglio, Giuseppe; Steegmann, Juan Luis; Shah, Neil P.; Boqué, Concepción; Chuah, Charles; Pavlovsky, Carolina; Mayer, Jiří; Cortes, Jorge; Baccarani, Michele; Kim, Dong-Wook; Bradley-Garelik, M. Brigid; Mohamed, Hesham; Wildgust, Mark; Hochhaus, Andreas

2014-01-01

This analysis explores the impact of early cytogenetic and molecular responses on the outcomes of patients with chronic myeloid leukemia in chronic phase (CML-CP) in the phase 3 DASatinib versus Imatinib Study In treatment-Naive CML patients trial with a minimum follow-up of 3 years. Patients with newly diagnosed CML-CP were randomized to receive 100 mg dasatinib (n = 259) or 400 mg imatinib (n = 260) once daily. The retrospective landmark analysis included patients evaluable at the relevant time point (3, 6, or 12 months). Median time to complete cytogenetic response was 3 vs 6 months with dasatinib vs imatinib. At 3 and 6 months, the proportion of patients with BCR-ABL transcript levels ≤10% was higher in the dasatinib arm. Deeper responses at 3, 6, and 12 months were observed in a higher proportion of patients on dasatinib therapy and were associated with better 3-year progression-free survival and overall survival in both arms. First-line dasatinib resulted in faster and deeper responses compared with imatinib. The achievement of an early molecular response was predictive of improved progression-free survival and overall survival, supporting new milestones for optimal response in patients with early CML-CP treated with tyrosine kinase inhibitors. This study was registered at www.clinicaltrials.gov as NCT00481247. PMID:24311723

Clinical relevance of the breakpoint sites within the M-BCR in 50 patients from Argentina with chronic myeloid leukemia.

PubMed

Giere, I A; Larripa, I B

1996-08-01

Fifty patients from Argentina with chronic myeloid leukemia (CML) were studied in order to characterize the breakpoint site within the major breakpoint cluster region (M-BCR) and its relationship with the duration of the chronic phase (CP). The DNA digestion with the restriction enzymes: Bgl II, BAM HI and Hind III and hybridization with the 1.2Kb Hind III-Bgl II bcr probe showed that 56% of cases had the breakpoint in 5'M-bcr region and the remaining 44% in 3'M-bcr region. The duration of chronic phase from diagnosis to the onset of the blast crisis (BC) was correlated with the location of the breakpoint within the M-bcr and no statistical differences were observed between the 5' and the 3' groups. These data indicate that the breakpoint site within the bcr gene is not a prognostic indicator of the duration of CP of the disease.

The mutation profile of JAK2, MPL and CALR in Mexican patients with Philadelphia chromosome-negative myeloproliferative neoplasms.

PubMed

Labastida-Mercado, Nancy; Galindo-Becerra, Samantha; Garcés-Eisele, Javier; Colunga-Pedraza, Perla; Guzman-Olvera, Valeria; Reyes-Nuñez, Virginia; Ruiz-Delgado, Guillermo J; Ruiz-Argüelles, Guillermo J

2015-03-01

By using molecular markers, it is possible to gain information on both the classification and etiopathogenesis of chronic myeloproliferative neoplasias (MPN). In a group of 27 Mexican mestizo patients with MPNs, we studied seven molecular markers: the BCR/ABL1 fusion gene, the JAK2 V617F mutation, the JAK2 exon 12 mutations, the MPL W515L mutation, the MPL W515K mutation, and the calreticulin (CALR) exon 9 deletion or insertion. Patients with the BCR/ABL1 fusion gene were excluded. We studied 14 patients with essential thrombocythemia (ET), eight with polycythemia vera (PV), four with primary myelofibrosis (MF), and one with undifferentiated MPN. We found twelve individuals with the JAK2 V617F mutation; five of them had been clinically classified as PV, five as ET, and one as MF. One patient with the MPL W515L was identified with a clinical picture of ET. Five patients with the CALR mutation were identified, four ET and one MF. No individuals with either the MPL W515K mutation or the JAK2 exon 12 mutations were identified. The most consistent relationship was that between PV and the JAK2 V617F mutation (p=.01). Despite its small size, the study shows much less prevalence of JAK2 mutation in PV, ET and MF, which does not match international data. Copyright © 2015 King Faisal Specialist Hospital & Research Centre. Published by Elsevier B.V. All rights reserved.

SAHA and S116836, a novel tyrosine kinase inhibitor, synergistically induce apoptosis in imatinib-resistant chronic myelogenous leukemia cells

PubMed Central

Bu, Qiangui; Cui, Lijing; Li, Juan; Du, Xin; Zou, Waiyi; Ding, Ke; Pan, Jingxuan

2014-01-01

Limited treatment options are available for chronic myelogenous leukemia (CML) patients who develop imatinib mesylate (IM) resistance. Here we proposed a novel combination regimen, a co-administration of S116836, a novel small molecule multi-targeted tyrosine kinase inhibitor that was synthesized by rational design, and histone deacetylases inhibitor (HDACi) suberoylanilide hydroxamic acid (SAHA), to overcome IM resistance in CML. S116836 at low concentrations used in the present study mildly downregulates auto-tyrosine phosphorylation of Bcr-Abl. SAHA, an FDA-approved HDACi drug, at 1 μM has modest anti-tumor activity in treating CML. However, we found a synergistic interaction between SAHA and S116836 in Bcr-Abl-positive CML cells that were sensitive or resistant to IM. Exposure of KBM5 and KBM5-T315I cells to minimal or non-toxic concentrations of SAHA and S116836 synergistically reduced cell viability and induced cell death. Co-treatment with SAHA and S116838 repressed the expressions of anti-apoptosis proteins, such as Mcl-1 and XIAP, but promoted Bim expression and mitochondrial damage. Of importance, treatment with both drugs significantly reduced cell viability of primary human CML cells, as compared with either agent alone. Taken together, our findings suggest that SAHA exerts synergistically with S116836 at a non-toxic concentration to promote apoptosis in the CML, including those resistant to imatinib or dasatinib. PMID:24759597

Genetic alterations activating kinase and cytokine receptor signaling in high-risk acute lymphoblastic leukemia

PubMed Central

Roberts, Kathryn G.; Morin, Ryan D.; Zhang, Jinghui; Hirst, Martin; Zhao, Yongjun; Su, Xiaoping; Chen, Shann-Ching; Payne-Turner, Debbie; Churchman, Michelle; Harvey, Richard C.; Chen, Xiang; Kasap, Corynn; Yan, Chunhua; Becksfort, Jared; Finney, Richard P.; Teachey, David T.; Maude, Shannon L.; Tse, Kane; Moore, Richard; Jones, Steven; Mungall, Karen; Birol, Inanc; Edmonson, Michael N.; Hu, Ying; Buetow, Kenneth E.; Chen, I-Ming; Carroll, William L.; Wei, Lei; Ma, Jing; Kleppe, Maria; Levine, Ross L.; Garcia-Manero, Guillermo; Larsen, Eric; Shah, Neil P.; Devidas, Meenakshi; Reaman, Gregory; Smith, Malcolm; Paugh, Steven W.; Evans, William E.; Grupp, Stephan A.; Jeha, Sima; Pui, Ching-Hon; Gerhard, Daniela S.; Downing, James R.; Willman, Cheryl L.; Loh, Mignon; Hunger, Stephen P.; Marra, Marco; Mullighan, Charles G.

2012-01-01

SUMMARY Genomic profiling has identified a subtype of high-risk B-progenitor acute lymphoblastic leukemia (B-ALL) with alteration of IKZF1, a gene expression profile similar to BCR-ABL1-positive ALL and poor outcome (Ph-like ALL). The genetic alterations that activate kinase signaling in Ph-like ALL are poorly understood. We performed transcriptome and whole genome sequencing on 15 cases of Ph-like ALL, and identified rearrangements involving ABL1, JAK2, PDGFRB, CRLF2 and EPOR, activating mutations of IL7R and FLT3, and deletion of SH2B3, which encodes the JAK2 negative regulator LNK. Importantly, several of these alterations induce transformation that is attenuated with tyrosine kinase inhibitors, suggesting the treatment outcome of these patients may be improved with targeted therapy. PMID:22897847

Tolerance to quaternary ammonium compound disinfectants may enhance growth of Listeria monocytogenes in the food industry.

PubMed

Møretrø, Trond; Schirmer, Bjørn C T; Heir, Even; Fagerlund, Annette; Hjemli, Pernille; Langsrud, Solveig

2017-01-16

The antibacterial effect of disinfectants is crucial for the control of Listeria monocytogenes in food processing environments. Tolerance of L. monocytogenes to sublethal levels of disinfectants based on quaternary ammonium compounds (QAC) is conferred by the resistance determinants qacH and bcrABC. The presence and distribution of these genes have been anticipated to have a role in the survival and growth of L. monocytogenes in food processing environments where QAC based disinfectants are in common use. In this study, a panel of 680 L. monocytogenes from nine Norwegian meat- and salmon processing plants were grouped into 36 MLVA profiles. The presence of qacH and bcrABC was determined in 101 isolates from the 26 most common MLVA profiles. Five MLVA profiles contained qacH and two contained bcrABC. Isolates with qacH and bcrABC showed increased tolerance to the QAC Benzalkonium chloride (BC), with minimal inhibitory concentrations (MICs) of 5-12, 10-13 and <5ppm for strains with qacH (two allele variants observed), bcrABC, and neither gene, respectively. Isolates with qacH or bcrABC were not more tolerant to BC in bactericidal tests in suspension or in biofilms compared with isolates lacking the genes. Water residue samples collected from surfaces in meat processing plants after QAC disinfection had bactericidal effect against L. monocytogenes when the sample BC levels were high (>100ppm). A sample with lower BC concentrations (14ppm of chain length C-12 and 2.7ppm of chain length C-14) inhibited growth of L. monocytogenes not containing bcrABC or qacH, compared to strains with these genes. The study has shown that L. monocytogenes harbouring the QAC resistance genes qacH and bcrABC are prevalent in the food industry and that residuals of QAC may be present in concentrations after sanitation in the industry that result in a growth advantage for bacteria with such resistance genes. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Diffuse large B-cell lymphoma patient-derived xenograft models capture the molecular and biological heterogeneity of the disease.

PubMed

Chapuy, Bjoern; Cheng, Hongwei; Watahiki, Akira; Ducar, Matthew D; Tan, Yuxiang; Chen, Linfeng; Roemer, Margaretha G M; Ouyang, Jing; Christie, Amanda L; Zhang, Liye; Gusenleitner, Daniel; Abo, Ryan P; Farinha, Pedro; von Bonin, Frederike; Thorner, Aaron R; Sun, Heather H; Gascoyne, Randy D; Pinkus, Geraldine S; van Hummelen, Paul; Wulf, Gerald G; Aster, Jon C; Weinstock, David M; Monti, Stefano; Rodig, Scott J; Wang, Yuzhuo; Shipp, Margaret A

2016-05-05

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease defined by transcriptional classifications, specific signaling and survival pathways, and multiple low-frequency genetic alterations. Preclinical model systems that capture the genetic and functional heterogeneity of DLBCL are urgently needed. Here, we generated and characterized a panel of large B-cell lymphoma (LBCL) patient-derived xenograft (PDX) models, including 8 that reflect the immunophenotypic, transcriptional, genetic, and functional heterogeneity of primary DLBCL and 1 that is a plasmablastic lymphoma. All LBCL PDX models were subjected to whole-transcriptome sequencing to classify cell of origin and consensus clustering classification (CCC) subtypes. Mutations and chromosomal rearrangements were evaluated by whole-exome sequencing with an extended bait set. Six of the 8 DLBCL models were activated B-cell (ABC)-type tumors that exhibited ABC-associated mutations such as MYD88, CD79B, CARD11, and PIM1. The remaining 2 DLBCL models were germinal B-cell type, with characteristic alterations of GNA13, CREBBP, and EZH2, and chromosomal translocations involving IgH and either BCL2 or MYC Only 25% of the DLBCL PDX models harbored inactivating TP53 mutations, whereas 75% exhibited copy number alterations of TP53 or its upstream modifier, CDKN2A, consistent with the reported incidence and type of p53 pathway alterations in primary DLBCL. By CCC criteria, 6 of 8 DLBCL PDX models were B-cell receptor (BCR)-type tumors that exhibited selective surface immunoglobulin expression and sensitivity to entospletinib, a recently developed spleen tyrosine kinase inhibitor. In summary, we have established and characterized faithful PDX models of DLBCL and demonstrated their usefulness in functional analyses of proximal BCR pathway inhibition. © 2016 by The American Society of Hematology.

The genetic polymorphism and expression profiles of NLRP3 inflammasome in patients with chronic myeloid leukemia.

PubMed

Zhang, Amin; Yu, Jie; Yan, Shuxin; Zhao, Xia; Chen, Chen; Zhou, Ying; Zhao, Xueyun; Hua, Mingqiang; Wang, Ruiqing; Zhang, Chen; Zhong, Chaoqin; He, Na; Ji, Chunyan; Ma, Daoxin

2018-01-01

NLRP3 inflammasome has been recently reported as an important risk factor in the development of cancer. But the relationship between polymorphisms of NLRP3 inflammasome related genes and chronic myeloid leukemia (CML) is rarely reported. Therefore, the aim of the present study was to investigate the association of five genetic polymorphisms (NLRP3, IL-1β, IL-18, CARD8 and NF-κB) in 267 CML patients and 344 healthy controls. We found that the AT genotype of CARD8 (rs2043211) was significantly higher compared to TT genotype in high and intermediate risk CML patients. IL-1β (rs16944) polymorphism in early molecular response at 6 months was marginally different, with more GG and less AA genotype in BCR-ABL IS >1% group. IL-18 (rs1946518) polymorphism was significantly different with more GG genotype in BCR-ABL IS >1% group at 6 months. We also demonstrated that WBC count of newly diagnosed patients carrying AG genotype was significantly higher than that of GG or AA genotype of IL-1β (rs16944). The onset age of patients carrying ins/ins genotype of NF-κB (rs28362491) was significantly older than that of ins/del and del/del genotype. Moreover, IL-1β or NLRP3 mRNA expression was decreased and IL-18 mRNA expression was increased significantly in CML patients compared with controls. In conclusion, the genetic polymorphisms of NLRP3 inflammasome may be served as potential predictors for CML. Copyright © 2017 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Effects of fish oils on ex vivo B-cell responses of obese subjects upon BCR/TLR stimulation: a pilot study.

PubMed

Guesdon, William; Kosaraju, Rasagna; Brophy, Patricia; Clark, Angela; Dillingham, Steve; Aziz, Shahnaz; Moyer, Fiona; Willson, Kate; Dick, James R; Patil, Shivajirao Prakash; Balestrieri, Nicholas; Armstrong, Michael; Reisdroph, Nichole; Shaikh, Saame Raza

2018-03-01

The long-chain n-3 polyunsaturated fatty acids (LC-PUFAs) eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) in fish oil have immunomodulatory properties. B cells are a poorly studied target of EPA/DHA in humans. Therefore, in this pilot study, we tested how n-3 LC-PUFAs influence B-cell responses of obese humans. Obese men and women were assigned to consume four 1-g capsules per day of olive oil (OO, n=12), fish oil (FO, n=12) concentrate or high-DHA-FO concentrate (n=10) for 12 weeks in a parallel design. Relative to baseline, FO (n=9) lowered the percentage of circulating memory and plasma B cells, whereas the other supplements had no effect. There were no postintervention differences between the three supplements. Next, ex vivo B-cell cytokines were assayed after stimulation of Toll-like receptors (TLRs) and/or the B-cell receptor (BCR) to determine if the effects of n-3 LC-PUFAs were pathway-dependent. B-cell IL-10 and TNFα secretion was respectively increased with high DHA-FO (n=10), relative to baseline, with respective TLR9 and TLR9+BCR stimulation. OO (n=12) and FO (n=12) had no influence on B-cell cytokines compared to baseline, and there were no differences in postintervention cytokine levels between treatment groups. Finally, ex vivo antibody levels were assayed with FO (n=7) after TLR9+BCR stimulation. Compared to baseline, FO lowered IgM but not IgG levels accompanied by select modifications to the plasma lipidome. Altogether, the results suggest that n-3 LC-PUFAs could modulate B-cell activity in humans, which will require further testing in a larger cohort. Copyright © 2017 Elsevier Inc. All rights reserved.

New and emerging prognostic and predictive genetic biomarkers in B-cell precursor acute lymphoblastic leukemia

PubMed Central

Moorman, Anthony V.

2016-01-01

Acute lymphoblastic leukemia (ALL) is a heterogeneous disease at the genetic level. Chromosomal abnormalities are used as diagnostic, prognostic and predictive biomarkers to provide subtype, outcome and drug response information. t(12;21)/ETV6-RUNX1 and high hyper-diploidy are good-risk prognostic biomarkers whereas KMT2A (MLL) translocations, t(17;19)/TCF3-HLF, haploidy or low hypodiploidy are high-risk biomarkers. t(9;22)/BCR-ABL1 patients require targeted treatment (imatinib/dasatinib), whereas iAMP21 patients achieve better outcomes when treated intensively. High-risk genetic biomarkers are four times more prevalent in adults compared to children. The application of genomic technologies to cases without an established abnormality (B-other) reveals copy number alterations which can be used either individually or in combination as prognostic biomarkers. Transcriptome sequencing studies have identified a network of fusion genes involving kinase genes - ABL1, ABL2, PDGFRB, CSF1R, CRLF2, JAK2 and EPOR. In vitro and in vivo studies along with emerging clinical observations indicate that patients with a kinase-activating aberration may respond to treatment with small molecular inhibitors like imatinib/dasatinib and ruxolitinib. Further work is required to determine the true frequency of these abnormalities across the age spectrum and the optimal way to incorporate such inhibitors into protocols. In conclusion, genetic biomarkers are playing an increasingly important role in the management of patients with ALL. PMID:27033238

Management of Chronic Myeloid Leukemia Patients Resistant to Tyrosine Kinase Inhibitors Treatment

PubMed Central

Wieczorek, Agnieszka; Uharek, Lutz

2015-01-01

Chronic myeloid leukemia (CML) is a myeloproliferative disorder associated with a characteristic chromosomal translocation called the Philadelphia chromosome. This oncogene is generated by the fusion of breakpoint cluster region (BCR) and Abelson leukemia virus (ABL) genes and encodes a novel fusion gene translating into a protein with constitutive tyrosine kinase activity. The discovery and introduction of tyrosine kinase inhibitors (TKIs) irreversibly changed the landscape of CML treatment, leading to dramatic improvement in long-term survival rates. The majority of patients with CML in the chronic phase have a life expectancy comparable with that of healthy age-matched individuals. Although an enormous therapeutic improvement has been accomplished, there are still some unresolved issues in the treatment of patients with CML. One of the most important problems is based on the fact that TKIs can efficiently target proliferating mature cells but do not eradicate leukemic stem cells, allowing persistence of the malignant clone. Owing to the resistance mechanisms arising during the course of the disease, treatment with most of the approved BCR-ABL1 TKIs may become ineffective in a proportion of patients. This article highlights the different molecular mechanisms of acquired resistance being developed during treatment with TKIs as well as the pharmacological strategies to overcome it. Moreover, it gives an overview of novel drugs and therapies that are aiming in overcoming drug resistance, loss of response, and kinase domain mutations. PMID:26917943

Myeloproliferative Neoplasms in Children.

PubMed

Hofmann, Inga

2015-09-01

Myeloproliferative neoplasms (MPN) are a group of clonal hematopoietic stem cell disorders characterized by aberrant proliferation of one or more myeloid lineages often with increased immature cells in the peripheral blood. The three classical BCR-ABL-negative MPNs are: 1) polycythemia vera (PV), 2) essential thrombocythemia (ET), and 3) primary myelofibrosis (PMF), which are typically disorders of older adults and are exceedingly rare in children. The diagnostic criteria for MPNs remain largely defined by clinical, laboratory and histopathology assessments in adults, but they have been applied to the pediatric population. The discovery of the JAK2 V617F mutation, and more recently, MPL and CALR mutations, are major landmarks in the understanding of MPNs. Nevertheless, they rarely occur in children, posing a significant diagnostic challenge given the lack of an objective, clonal marker. Therefore, in pediatric patients, the diagnosis must rely heavily on clinical and laboratory factors, and exclusion of secondary disorders to make an accurate diagnosis of MPN. This review focuses on the clinical presentation, diagnostic work up, differential diagnosis, treatment and prognosis of the classical BCR-ABL-negative MPNs (PV, ET and PMF) in children and highlights key differences to the adult diseases. Particular attention will be given to pediatric PMF, as it is the only disorder of this group that is observed in infants and young children, and in many ways appears to be a unique entity compared to adult PMF.

Bleeding complications in BCR-ABL negative myeloproliferative neoplasms: prevalence, type, and risk factors in a single-center cohort.

PubMed

Kander, Elizabeth M; Raza, Sania; Zhou, Zheng; Gao, Juehua; Zakarija, Anaadriana; McMahon, Brandon J; Stein, Brady L

2015-11-01

The BCR-ABL1-negative myeloproliferative neoplasms (MPN) share an increased risk of thrombotic and hemorrhagic complications. Risk factors for hemorrhage are less well defined than those for thrombosis. Because patients with CALR mutations have higher platelet counts compared to JAK2 V617F-mutated patients, bleeding rates may be increased in this group. Our aim was to retrospectively evaluate whether acquired von Willebrand disease (AvWD), thrombocytosis, mutational status, or treatment history are associated with bleeding in a cohort of MPN patients. Using an electronic database, MPN patients seen between 2005 and 2013 were retrospectively identified using ICD-9 codes and billing records. A bleeding event was defined as one that was identified in the medical record and graded based on the Common Terminology Criteria for Adverse Event (CTCAE) version 4.0. Among 351 MPN patients, 15.6 % experienced 64 bleeding event types. There was no association of bleeding with mutational status, gender, MPN subtype, aspirin use, prior thrombosis, or platelet count at presentation. There was an association between bleeding and older age at diagnosis. aVWD was identified in six patients. In this single-center retrospective study, bleeding events were identified in 15 % of patients, and associated with older age at diagnosis. aVWD was rarely tested for in this cohort.

Chronic myelocytic leukaemia with unusual (27 years) complete remission terminating in acute undifferentiated leukaemia: a clinical and karyotypic study.

PubMed

Najean, Y; Miclea, M; Tanzer, J; Lessard, M; Sigaux, F

1991-07-01

A case of clinically typical CML (300 x 10(6)/l leukocytes, 400 x 10(6)/l platelets, splenomegaly) is presented. After complete remission induced by busulphan, no clinical or haematological abnormalities were observed for 27 years until the development of acute leukaemia (type M1), which was rapidly fatal after a brief chemotherapy-induced remission. The cytogenetic findings were also original: no chromosome Ph1 (during remission 3 years after the onset of the disease), no translocation (banding study 5 years later), and no bcr/abl rearrangement (during the terminal phase).

Current trends in molecular diagnostics of chronic myeloid leukemia.

PubMed

Vinhas, Raquel; Cordeiro, Milton; Pedrosa, Pedro; Fernandes, Alexandra R; Baptista, Pedro V

2017-08-01

Nearly 1.5 million people worldwide suffer from chronic myeloid leukemia (CML), characterized by the genetic translocation t(9;22)(q34;q11.2), involving the fusion of the Abelson oncogene (ABL1) with the breakpoint cluster region (BCR) gene. Early onset diagnosis coupled to current therapeutics allow for a treatment success rate of 90, which has focused research on the development of novel diagnostics approaches. In this review, we present a critical perspective on current strategies for CML diagnostics, comparing to gold standard methodologies and with an eye on the future trends on nanotheranostics.

ON012380: A Non-ATP Competitive Inhibitor of BCR-ABL for the Therapy of Imatinib-Resistant CMLs

DTIC Science & Technology

2007-05-01

polycythemia vera (PV) as well as in some cases of essential thrombocythemia (ET) and chronic idiopathic myelofibrosis (CIMF), all of which are...in polycythemia vera, essential thrombocythemia, and myeloid metaplasia with myelofibrosis. Cancer Cell. 7(4):387-97. 20 Meydan N, Grunberger T

Lck is a relevant target in chronic lymphocytic leukaemia cells whose expression variance is unrelated to disease outcome.

PubMed

Till, Kathleen J; Allen, John C; Talab, Fatima; Lin, Ke; Allsup, David; Cawkwell, Lynn; Bentley, Alison; Ringshausen, Ingo; Duckworth, Andrew D; Pettitt, Andrew R; Kalakonda, Nagesh; Slupsky, Joseph R

2017-12-01

Pathogenesis of chronic lymphocytic leukaemia (CLL) is contingent upon antigen receptor (BCR) expressed by malignant cells of this disease. Studies on somatic hypermutation of the antigen binding region, receptor expression levels and signal capacity have all linked BCR on CLL cells to disease prognosis. Our previous work showed that the src-family kinase Lck is a targetable mediator of BCR signalling in CLL cells, and that variance in Lck expression associated with ability of BCR to induce signal upon engagement. This latter finding makes Lck similar to ZAP70, another T-cell kinase whose aberrant expression in CLL cells also associates with BCR signalling capacity, but also different because ZAP70 is not easily pharmacologically targetable. Here we describe a robust method of measuring Lck expression in CLL cells using flow cytometry. However, unlike ZAP70 whose expression in CLL cells predicts prognosis, we find Lck expression and disease outcome in CLL are unrelated despite observations that its inhibition produces effects that biologically resemble the egress phenotype taken on by CLL cells treated with idelalisib. Taken together, our findings provide insight into the pathobiology of CLL to suggest a more complex relationship between expression of molecules within the BCR signalling pathway and disease outcome.

Ten-year experiences on initial genetic examination in childhood acute lymphoblastic leukaemia in Hungary (1993-2002). Technical approaches and clinical implementation.

PubMed

Olah, Eva; Balogh, Erzsebet; Pajor, Laszlo; Jakab, Zsuzsanna

2011-03-01

A nationwide study was started in 1993 to provide genetic diagnosis for all newly diagnosed childhood ALL cases in Hungary using cytogenetic examination, DNA-index determination, FISH (aneuploidy, ABL/BCR, TEL/AML1) and molecular genetic tests (ABL/BCR, MLL/AF4, TEL/AML1). Aim of the study was to assess the usefulness of different genetic methods, to study the frequency of various aberrations and their prognostic significance. Results were synthesized for genetic subgrouping of patients. To assess the prognostic value of genetic aberrations overall and event-free survival of genetic subgroups were compared using Kaplan-Meier method. Prognostic role of aberrations was investigated by multivariate analysis (Cox's regression) as well in comparison with other factors (age, sex, major congenital abnormalities, initial WBC, therapy, immunophenotype). Five hundred eighty-eight ALL cases were diagnosed between 1993-2002. Cytogenetic examination was performed in 537 (91%) (success rate 73%), DNA-index in 265 (45%), FISH in 74 (13%), TEL/AML1 RT-PCR in 219 (37%) cases producing genetic diagnosis in 457 patients (78%). Proportion of subgroups with good prognosis in prae-B-cell ALL was lower than expected: hyperdiploidB 18% (73/400), TEL/AML1+ 9% (36/400). Univariate analysis showed significantly better 5-year EFS in TEL/AML1+ (82%) and hyperdiploidB cases (78%) than in tetraploid (44%) or pseudodiploid (52%) subgroups. By multivariate analysis main negative prognostic factors were: congenital abnormalities, high WBC, delay in therapy, specific translocations. Complementary use of each of genetic methods used is necessary for reliable genetic diagnosis according to the algorithm presented. Specific genetic alterations proved to be of prognostic significance.

Immune Effector Recovery in Chronic Myeloid Leukemia and Treatment-Free Remission

PubMed Central

Hughes, Amy; Yong, Agnes S. M.

2017-01-01

Chronic myeloid leukemia (CML) is a hematological cancer, characterized by a reciprocal chromosomal translocation between chromosomes 9 and 22 [t(9;22)], producing the Bcr-Abl oncogene. Tyrosine kinase inhibitors (TKIs) represent the standard of care for CML patients and exert a dual mode of action: direct oncokinase inhibition and restoration of effector-mediated immune surveillance, which is rendered dysfunctional in CML patients at diagnosis, prior to TKI therapy. TKIs such as imatinib, and more potent second-generation nilotinib and dasatinib induce a high rate of deep molecular response (DMR, BCR-ABL1 ≤ 0.01%) in CML patients. As a result, the more recent goal of therapy in CML treatment is to induce a durable DMR as a prelude to successful treatment-free remission (TFR), which occurs in approximately half of all CML patients who cease TKI therapy. The lack of overt relapse in such patients has been attributed to immunological control of CML. In this review, we discuss an immunological timeline to successful TFR, focusing on the immunology of CML during TKI treatment; an initial period of immune suppression, limiting antitumor immune effector responses in newly diagnosed CML patients, linked to an expansion of immature myeloid-derived suppressor cells and regulatory T cells and aberrant expression of immune checkpoint signaling pathways, including programmed death-1/programmed death ligand-1. Commencement of TKI treatment is associated with immune system re-activation and restoration of effector-mediated [natural killer (NK) cell and T cell] immune surveillance in CML patients, albeit with differing frequencies in concert with differing levels of molecular response achieved on TKI. DMR is associated with maximal restoration of immune recovery in CML patients on TKI. Current data suggest a net balance between both the effector and suppressor arms of the immune system, at a minimum involving mature, cytotoxic CD56dim NK cells may be important in mediating TFR success. However, a major goal remains in CML to identify the most effective pathways to target to maximize an advantageous immune response and promote TFR success. PMID:28484463

The B-cell receptor controls fitness of MYC-driven lymphoma cells via GSK3β inhibition.

PubMed

Varano, Gabriele; Raffel, Simon; Sormani, Martina; Zanardi, Federica; Lonardi, Silvia; Zasada, Christin; Perucho, Laura; Petrocelli, Valentina; Haake, Andrea; Lee, Albert K; Bugatti, Mattia; Paul, Ulrike; Van Anken, Eelco; Pasqualucci, Laura; Rabadan, Raul; Siebert, Reiner; Kempa, Stefan; Ponzoni, Maurilio; Facchetti, Fabio; Rajewsky, Klaus; Casola, Stefano

2017-06-08

Similar to resting mature B cells, where the B-cell antigen receptor (BCR) controls cellular survival, surface BCR expression is conserved in most mature B-cell lymphomas. The identification of activating BCR mutations and the growth disadvantage upon BCR knockdown of cells of certain lymphoma entities has led to the view that BCR signalling is required for tumour cell survival. Consequently, the BCR signalling machinery has become an established target in the therapy of B-cell malignancies. Here we study the effects of BCR ablation on MYC-driven mouse B-cell lymphomas and compare them with observations in human Burkitt lymphoma. Whereas BCR ablation does not, per se, significantly affect lymphoma growth, BCR-negative (BCR - ) tumour cells rapidly disappear in the presence of their BCR-expressing (BCR + ) counterparts in vitro and in vivo. This requires neither cellular contact nor factors released by BCR + tumour cells. Instead, BCR loss induces the rewiring of central carbon metabolism, increasing the sensitivity of receptor-less lymphoma cells to nutrient restriction. The BCR attenuates glycogen synthase kinase 3 beta (GSK3β) activity to support MYC-controlled gene expression. BCR - tumour cells exhibit increased GSK3β activity and are rescued from their competitive growth disadvantage by GSK3β inhibition. BCR - lymphoma variants that restore competitive fitness normalize GSK3β activity after constitutive activation of the MAPK pathway, commonly through Ras mutations. Similarly, in Burkitt lymphoma, activating RAS mutations may propagate immunoglobulin-crippled tumour cells, which usually represent a minority of the tumour bulk. Thus, while BCR expression enhances lymphoma cell fitness, BCR-targeted therapies may profit from combinations with drugs targeting BCR - tumour cells.

Musashi-2 regulates normal hematopoiesis and promotes aggressive myeloid leukemia

PubMed Central

Kharas, Michael G; Lengner, Christopher J; Al-Shahrour, Fatima; Bullinger, Lars; Ball, Brian; Zaidi, Samir; Morgan, Kelly; Tam, Winnie; Paktinat, Mahnaz; Okabe, Rachel; Gozo, Maricel; Einhorn, William; Lane, Steven W; Scholl, Claudia; Fröhling, Stefan; Fleming, Mark; Ebert, Benjamin L; Gilliland, D Gary; Jaenisch, Rudolf; Daley, George Q

2011-01-01

RNA-binding proteins of the Musashi (Msi) family are expressed in stem cell compartments and in aggressive tumors, but they have not yet been widely explored in the blood. Here we demonstrate that Msi2 is the predominant form expressed in hematopoietic stem cells (HSCs), and its knockdown leads to reduced engraftment and depletion of HSCs in vivo. Overexpression of human MSI2 in a mouse model increases HSC cell cycle progression and cooperates with the chronic myeloid leukemia–associated BCR-ABL1 oncoprotein to induce an aggressive leukemia. MSI2 is overexpressed in human myeloid leukemia cell lines, and its depletion leads to decreased proliferation and increased apoptosis. Expression levels in human myeloid leukemia directly correlate with decreased survival in patients with the disease, thereby defining MSI2 expression as a new prognostic marker and as a new target for therapy in acute myeloid leukemia (AML). PMID:20616797

A risk-adjusted definition of biochemical recurrence after radical prostatectomy.

PubMed

Morgan, T M; Meng, M V; Cooperberg, M R; Cowan, J E; Weinberg, V; Carroll, P R; Lin, D W

2014-06-01

To determine whether a variable definition of biochemical recurrence (BCR) based on clincopathologic features facilitates early identification of patients likely to suffer from disease progression. The definition of BCR after radical prostatectomy (RP) bears important implications for patient counseling and management; however, there remains a significant debate regarding the appropriate definition. The study cohort consisted of 3619 men who underwent RP for localized prostate cancer from 1989 to 2007, with data abstracted from the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) registry. Patients were stratified into three risk groups according to Cancer of the Prostate Risk Assessment post-Surgical (CAPRA-S) score. Three single threshold PSA cut-points for BCR were evaluated (PSA > or =0.05, > or =0.2 and > or =0.4 ng ml(-1)) as well as a variable cut-point defined by risk group. After reaching the cut-points, patients were followed for further PSA progression. The proportion of patients with BCR differed by cut-point and risk group, ranging from 7 to 37% (low risk), 22 to 58% (intermediate risk) and 60 to 86% (high risk). The positive-predictive value (PPV) for predicting further PSA progression was 49% for the PSA > or =0.05 ng ml(-1), 62% for the PSA > or =0.2 ng ml(-1), 65% for the PSA > or =0.4 ng ml(-1) and 68% for the risk-adjusted definition. Five-year progression-free survival was 39% for the risk-adjusted definition compared with 45-52% for the other definitions of BCR. These data suggest that a variable definition of BCR determined by clinicopathologic risk may improve the identification of early recurrence after RP without increasing the overdiagnosis of BCR. By using a risk-adjusted BCR definition, clinicians can better predict future PSA progression and more appropriately counsel patients regarding salvage therapies.

Donor Umbilical Cord Blood Transplant With or Without Ex-vivo Expanded Cord Blood Progenitor Cells in Treating Patients With Acute Myeloid Leukemia, Acute Lymphoblastic Leukemia, Chronic Myelogenous Leukemia, or Myelodysplastic Syndromes

ClinicalTrials.gov

2018-03-05

Acute Biphenotypic Leukemia; Acute Erythroid Leukemia; Acute Lymphoblastic Leukemia in Remission; Acute Megakaryoblastic Leukemia; Acute Myeloid Leukemia Arising From Previous Myelodysplastic Syndrome; Acute Myeloid Leukemia in Remission; Blasts Under 10 Percent of Bone Marrow Nucleated Cells; Blasts Under 5 Percent of Bone Marrow Nucleated Cells; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Mixed Phenotype Acute Leukemia; Myelodysplastic Syndrome; Myelodysplastic Syndrome With Excess Blasts; Pancytopenia; Refractory Anemia; Secondary Acute Myeloid Leukemia

Chromium exposure among children from an electronic waste recycling town of China.

PubMed

Xu, Xijin; Yekeen, Taofeek Akangbe; Liu, Junxiao; Zhuang, Bingrong; Li, Weiqiu; Huo, Xia

2015-02-01

Guiyu is one of the most heavily chromium-polluted areas in China due to the numerous informal electronic waste (e-waste) recycling activities. A 3-year (2004, 2006, and 2008) independent cross-sectional study on blood chromium (BCr) levels of 711 children from Guiyu and a control area was investigated. Questionnaire completed by parents/guardians was used to assess the risk factors of chromium (Cr) exposure, while physical examination, for the year 2008 only, was used to evaluate the effects of long-term exposure to Cr on child physical development. Children living in Guiyu had significantly higher BCr levels compared with those living in Chendian at the same period from 2004 to 2008 (P < 0.001). The predominant risk factors related to elevated child BCr levels included the use of house as a family workshop, parent involved in e-waste recycling, and child residence in Guiyu. Children's weight and chest circumferences in group with high exposure to Cr (upper quartile) were higher than in the low-exposure group (P < 0.01), although the difference was less significant for boys between the two groups (P < 0.05). The results suggest that elevated child BCr in Guiyu due to informal e-waste recycling activities might be threatening the health of children, with implications on physical growth and development.

Women Administered Standard Dose Imatinib for Chronic Myeloid Leukemia Have Higher Dose-Adjusted Plasma Imatinib and Norimatinib Concentrations Than Men.

PubMed

Belsey, Sarah L; Ireland, Robin; Lang, Kathryn; Kizilors, Aytug; Ho, Aloysius; Mufti, Ghulam J; Bisquera, Alessandra; De Lavallade, Hugues; Flanagan, Robert J

2017-10-01

The standard dose of imatinib for the treatment of chronic-phase chronic myeloid leukemia (CML) is 400 mg·d. A predose plasma imatinib concentration of >1 mg·L is associated with improved clinical response. This study aimed to assess the plasma imatinib and norimatinib concentrations attained in patients with chronic myeloid leukemia administered standard doses of imatinib adjusted for dose, age, sex, body weight, and response. We evaluated data from a cohort of patients treated between 2008 and 2014 with respect to dose, age, sex, body weight, and response. The study comprised 438 samples from 93 patients (54 male, 39 female). The median imatinib dose was 400 mg·d in men and in women. The plasma imatinib concentration ranged 0.1-5.0 mg·L and was below 1 mg·L in 20% and 16% of samples from men and women, respectively. The mean dose normalized plasma imatinib and norimatinib concentrations were significantly higher in women in comparison with men. This was partially related to body weight. Mixed effects ordinal logistic regression showed no evidence of an association between sex and plasma imatinib (P = 0.13). However, there was evidence of an association between sex and plasma norimatinib, with higher norimatinib concentrations more likely in women than in men (P = 0.02). Imatinib therapeutic drug monitoring only provides information on dosage adequacy and on short-term adherence; longer-term adherence cannot be assessed. However, this analysis revealed that approximately 1 in 5 samples had a plasma imatinib concentration <1 mg·L, which was suggestive of inadequate dosage and/or poor adherence and posed a risk of treatment failure. Higher imatinib exposure in women may be a factor in the increased rate of long-term, stable, deep molecular response (undetectable breakpoint cluster-Abelson (BCR-ABL) transcript levels with a PCR sensitivity of 4.5 log, MR4.5) reported in women.

Robotic-assisted pelvic lymph node dissection for prostate cancer: frequency of nodal metastases and oncological outcomes.

PubMed

Ledezma, Rodrigo A; Negron, Edris; Razmaria, Aria A; Dangle, Pankaj; Eggener, Scott E; Shalhav, Arieh L; Zagaja, Gregory P

2015-11-01

Limited data are available regarding the oncologic efficacy of pelvic lymph node dissection (PLND) performed during robotic-assisted laparoscopic prostatectomy (RALP) for prostate cancer. We aimed to determine the frequency of pelvic lymph node metastasis and oncological outcomes following RALP with PLND in patients who did not receive adjuvant androgen deprivation therapy (ADT). We retrospectively reviewed the records of 1740 consecutive patients who underwent RALP and extended PLND. The primary endpoint was biochemical recurrence (BCR). The estimated BCR probability was obtained using the Kaplan-Meier method. Cox proportional hazard regression models were used to assess for predictors of BCR. One hundred and eight patients (6 %) with positive LNs were identified. The median number of LNs removed was 17 (IQR 11-24), and median follow-up was 26 months (IQR 14-43). Ninety-one (84 %) patients did not receive adjuvant ADT of whom 60 % had BCR with a median time to recurrence of 8 months. The 1- and 3-year BCR-free probability was 42 and 28 %, respectively. Patients with ≤2 LN+ had significantly better biochemical-free estimated probability compared to those with >2 LN+ (p = 0.002). The total number of LN+ (HR = 1.1; 95 % CI 1.01-1.2, p = 0.04) and Gleason 8-10 (HR = 1.96; 95 % CI 1.1-3.4, p = 0.02) were predictors of BCR on multivariate analysis. Among men with positive lymph nodes at time of robotic prostatectomy, those with two or fewer positive nodes and Gleason <8 exhibited favorable biochemical-free survival without adjuvant therapy.

Human SLP-65 isoforms contribute differently to activation and apoptosis of B lymphocytes.

PubMed

Grabbe, Annika; Wienands, Jürgen

2006-12-01

The SH2 domain-containing leukocyte adaptor protein of 65 kDa (SLP-65) is the key effector for signaling downstream of the B-cell antigen receptor (BCR). SLP-65 controls not only B lymphopoiesis and humoral immunity but also possesses a yet poorly defined tumor suppressor activity that is lost in many cases of acute lymphoblastic leukemia. We found that the 2 isoforms of human SLP-65 are differentially involved in positive and negative B-cell signaling. Reconstitution experiments revealed that an atypical SH3 domain-binding motif, which is present in the long but not in the short SLP-65 isoform, mediates association to Grb2 and suppresses activation of mitogen-activated protein kinases p38 and JNK as well as up-regulation of c-Fos expression. In turn, the short isoform activates not only AP1-driven but also NF-kappaB-driven gene transcription more potently than the long isoform. Conversely, the long rather than the short SLP-65 isoform promotes BCR-induced B-cell apoptosis. Our data further delineate the structural requirements of positive and negative SLP-65 signal transduction in normal and neoplastic cells.

B cell receptor inhibition as a target for CLL therapy.

PubMed

Jeyakumar, Deepa; O'Brien, Susan

2016-03-01

Inhibitors of the B cell receptor (BCR) represent an attractive therapeutic option for patients with chronic lymphocytic leukemia. Recently approved inhibitors of Bruton's tyrosine kinase (ibrutinib) and phosphatidylinositol 3-kinase (idelalisib), are promising agents because they are generally well tolerated and highly effective. These agents may be particularly important in the treatment of older patients who are less able to tolerate the myelosuppression (and infections) associated with chemoimmunotherapy. As a class of medications, BCR inhibitors have some unique side effects including redistribution lymphocytosis. Ibrutinib has specific toxicities including increased risk for bleeding and atrial fibrillation. Idelalisib also has some unique toxicities consisting of transaminitis, diarrhea and pneumonitis. Ongoing clinical trials are evaluating these agents in combination with antibodies, chemotherapy and other small molecules. Copyright © 2016 Elsevier Ltd. All rights reserved.

ABI-like transcription factor gene TaABL1 from wheat improves multiple abiotic stress tolerances in transgenic plants.

PubMed

Xu, Dong-Bei; Gao, Shi-Qing; Ma, You-Zhi; Xu, Zhao-Shi; Zhao, Chang-Ping; Tang, Yi-Miao; Li, Xue-Yin; Li, Lian-Cheng; Chen, Yao-Feng; Chen, Ming

2014-12-01

The phytohormone abscisic acid (ABA) plays crucial roles in adaptive responses of plants to abiotic stresses. ABA-responsive element binding proteins (AREBs) are basic leucine zipper transcription factors that regulate the expression of downstream genes containing ABA-responsive elements (ABREs) in promoter regions. A novel ABI-like (ABA-insensitive) transcription factor gene, named TaABL1, containing a conserved basic leucine zipper (bZIP) domain was cloned from wheat. Southern blotting showed that three copies were present in the wheat genome. Phylogenetic analyses indicated that TaABL1 belonged to the AREB subfamily of the bZIP transcription factor family and was most closely related to ZmABI5 in maize and OsAREB2 in rice. Expression of TaABL1 was highly induced in wheat roots, stems, and leaves by ABA, drought, high salt, and low temperature stresses. TaABL1 was localized inside the nuclei of transformed wheat mesophyll protoplast. Overexpression of TaABL1 enhanced responses of transgenic plants to ABA and hastened stomatal closure under stress, thereby improving tolerance to multiple abiotic stresses. Furthermore, overexpression of TaABL1 upregulated or downregulated the expression of some stress-related genes controlling stomatal closure in transgenic plants under ABA and drought stress conditions, suggesting that TaABL1 might be a valuable genetic resource for transgenic molecular breeding.

Phase 1 dose-finding study of rebastinib (DCC-2036) in patients with relapsed chronic myeloid leukemia and acute myeloid leukemia

PubMed Central

Cortes, Jorge; Talpaz, Moshe; Smith, Hedy P.; Snyder, David S.; Khoury, Jean; Bhalla, Kapil N.; Pinilla-Ibarz, Javier; Larson, Richard; Mitchell, David; Wise, Scott C.; Rutkoski, Thomas J.; Smith, Bryan D.; Flynn, Daniel L.; Kantarjian, Hagop M.; Rosen, Oliver; Van Etten, Richard A.

2017-01-01

A vailable tyrosine kinase inhibitors for chronic myeloid leukemia bind in an adenosine 5′-triphosphate-binding pocket and are affected by evolving mutations that confer resistance. Rebastinib was identified as a switch control inhibitor of BCR-ABL1 and FLT3 and may be active against resistant mutations. A Phase 1, first-in-human, single-agent study investigated rebastinib in relapsed or refractory chronic or acute myeloid leukemia. The primary objectives were to investigate the safety of rebastinib and establish the maximum tolerated dose and recommended Phase 2 dose. Fifty-seven patients received treatment with rebastinib. Sixteen patients were treated using powder-in-capsule preparations at doses from 57 mg to 1200 mg daily, and 41 received tablet preparations at doses of 100 mg to 400 mg daily. Dose-limiting toxicities were dysarthria, muscle weakness, and peripheral neuropathy. The maximum tolerated dose was 150 mg tablets administered twice daily. Rebastinib was rapidly absorbed. Bioavailability was 3- to 4-fold greater with formulated tablets compared to unformulated capsules. Eight complete hematologic responses were achieved in 40 evaluable chronic myeloid leukemia patients, 4 of which had a T315I mutation. None of the 5 patients with acute myeloid leukemia responded. Pharmacodynamic analysis showed inhibition of phosphorylation of substrates of BCR-ABL1 or FLT3 by rebastinib. Although clinical activity was observed, clinical benefit was insufficient to justify continued development in chronic or acute myeloid leukemia. Pharmacodynamic analyses suggest that other kinases inhibited by rebastinib, such as TIE2, may be more relevant targets for the clinical development of rebastinib (clinicaltrials.gov Identifier:00827138). PMID:27927766

Phase 1 dose-finding study of rebastinib (DCC-2036) in patients with relapsed chronic myeloid leukemia and acute myeloid leukemia.

PubMed

Cortes, Jorge; Talpaz, Moshe; Smith, Hedy P; Snyder, David S; Khoury, Jean; Bhalla, Kapil N; Pinilla-Ibarz, Javier; Larson, Richard; Mitchell, David; Wise, Scott C; Rutkoski, Thomas J; Smith, Bryan D; Flynn, Daniel L; Kantarjian, Hagop M; Rosen, Oliver; Van Etten, Richard A

2017-03-01

A vailable tyrosine kinase inhibitors for chronic myeloid leukemia bind in an adenosine 5'-triphosphate-binding pocket and are affected by evolving mutations that confer resistance. Rebastinib was identified as a switch control inhibitor of BCR-ABL1 and FLT3 and may be active against resistant mutations. A Phase 1, first-in-human, single-agent study investigated rebastinib in relapsed or refractory chronic or acute myeloid leukemia. The primary objectives were to investigate the safety of rebastinib and establish the maximum tolerated dose and recommended Phase 2 dose. Fifty-seven patients received treatment with rebastinib. Sixteen patients were treated using powder-in-capsule preparations at doses from 57 mg to 1200 mg daily, and 41 received tablet preparations at doses of 100 mg to 400 mg daily. Dose-limiting toxicities were dysarthria, muscle weakness, and peripheral neuropathy. The maximum tolerated dose was 150 mg tablets administered twice daily. Rebastinib was rapidly absorbed. Bioavailability was 3- to 4-fold greater with formulated tablets compared to unformulated capsules. Eight complete hematologic responses were achieved in 40 evaluable chronic myeloid leukemia patients, 4 of which had a T315I mutation. None of the 5 patients with acute myeloid leukemia responded. Pharmacodynamic analysis showed inhibition of phosphorylation of substrates of BCR-ABL1 or FLT3 by rebastinib. Although clinical activity was observed, clinical benefit was insufficient to justify continued development in chronic or acute myeloid leukemia. Pharmacodynamic analyses suggest that other kinases inhibited by rebastinib, such as TIE2, may be more relevant targets for the clinical development of rebastinib ( clinicaltrials.gov Identifier:00827138 ). Copyright© Ferrata Storti Foundation.

Use of Multiple Imputation Method to Improve Estimation of Missing Baseline Serum Creatinine in Acute Kidney Injury Research

PubMed Central

Peterson, Josh F.; Eden, Svetlana K.; Moons, Karel G.; Ikizler, T. Alp; Matheny, Michael E.

2013-01-01

Summary Background and objectives Baseline creatinine (BCr) is frequently missing in AKI studies. Common surrogate estimates can misclassify AKI and adversely affect the study of related outcomes. This study examined whether multiple imputation improved accuracy of estimating missing BCr beyond current recommendations to apply assumed estimated GFR (eGFR) of 75 ml/min per 1.73 m2 (eGFR 75). Design, setting, participants, & measurements From 41,114 unique adult admissions (13,003 with and 28,111 without BCr data) at Vanderbilt University Hospital between 2006 and 2008, a propensity score model was developed to predict likelihood of missing BCr. Propensity scoring identified 6502 patients with highest likelihood of missing BCr among 13,003 patients with known BCr to simulate a “missing” data scenario while preserving actual reference BCr. Within this cohort (n=6502), the ability of various multiple-imputation approaches to estimate BCr and classify AKI were compared with that of eGFR 75. Results All multiple-imputation methods except the basic one more closely approximated actual BCr than did eGFR 75. Total AKI misclassification was lower with multiple imputation (full multiple imputation + serum creatinine) (9.0%) than with eGFR 75 (12.3%; P<0.001). Improvements in misclassification were greater in patients with impaired kidney function (full multiple imputation + serum creatinine) (15.3%) versus eGFR 75 (40.5%; P<0.001). Multiple imputation improved specificity and positive predictive value for detecting AKI at the expense of modestly decreasing sensitivity relative to eGFR 75. Conclusions Multiple imputation can improve accuracy in estimating missing BCr and reduce misclassification of AKI beyond currently proposed methods. PMID:23037980

CD22 ligation inhibits downstream B cell receptor signaling and Ca(2+) flux upon activation.

PubMed

Sieger, N; Fleischer, S J; Mei, H E; Reiter, K; Shock, A; Burmester, G R; Daridon, C; Dörner, T

2013-03-01

CD22 is a surface molecule exclusively expressed on B cells that regulates adhesion and B cell receptor (BCR) signaling as an inhibitory coreceptor of the BCR. Central downstream signaling molecules that are activated upon BCR engagement include spleen tyrosine kinase (Syk) and, subsequently, phospholipase Cγ2 (PLCγ2), which results in calcium (Ca(2+)) mobilization. The humanized anti-CD22 monoclonal antibody epratuzumab is currently being tested in clinical trials. This study was undertaken to determine the potential mechanism by which this drug regulates B cell activation. Purified B cells were preincubated with epratuzumab, and the colocalization of CD22 and CD79α, without BCR engagement, was assessed by confocal microscopy. The phosphorylation of Syk (Y348, Y352) and PLCγ2 (Y759) as well as the Ca(2+) flux in the cells were analyzed by flow cytometry upon stimulation of the BCR and/or Toll-like receptor 9 (TLR-9). The influence of CD22 ligation on BCR signaling was assessed by pretreating the cells with epratuzumab or F(ab')(2) fragment of epratuzumab, in comparison with control cells (medium alone or isotype-matched IgG1). Epratuzumab induced colocalization of CD22 and components of the BCR independent of BCR engagement, and also reduced intracellular Ca(2+) mobilization and diminished the phosphorylation of Syk and PLCγ2 after BCR stimulation in vitro. Inhibition of kinase phosphorylation was demonstrated in both CD27- and CD27+ B cells, and this appeared to be independent of Fc receptor signaling. Preactivation of the cells via the stimulation of TLR-9 did not circumvent the inhibitory effect of epratuzumab on BCR signaling. These findings are consistent with the concept of targeting CD22 to raise the threshold of BCR activation, which could offer therapeutic benefit in patients with autoimmune diseases. Copyright © 2013 by the American College of Rheumatology.

Time from first detectable PSA following radical prostatectomy to biochemical recurrence: A competing risk analysis.

PubMed

de Boo, Leonora; Pintilie, Melania; Yip, Paul; Baniel, Jack; Fleshner, Neil; Margel, David

2015-01-01

In this study, we estimated the time from first detectable prostate-specific antigen (PSA) following radical prostatectomy (RP) to commonly used definitions of biochemical recurrence (BCR). We also identified the predictors of time to BCR. We identified subjects who underwent a RP and had an undetectable PSA after surgery followed by at least 1 detectable PSA between 2000 and 2011. The primary outcome was time to BCR (PSA ≥0.2 and successive PSA ≥0.2) and prediction of the rate of PSA rise. Outcomes were calculated using a competing risk analysis, with univariable and multivariable Fine and Grey models. We employed a mixed effect model to test clinical predictors that are associated with the rate of PSA rise. The cohort included 376 patients. The median follow-up from surgery was 60.5 months (interquartile range [IQR] 40.8-91.5) and from detectable PSA was 18 months (IQR 11-32). Only 45.74% (n = 172) had PSA values ≥0.2 ng/mL, while 15.16% (n = 57) reached the PSA level of ≥0.4 ng/mL and rising. On multivariable analysis, the values of the first detectable PSA and pathologic Gleason grade 8 or higher were consistently independent predictors of time to BCR. In the mixed effect model rate, the PSA rise was associated with time from surgery to first detectable PSA, Gleason score, and prostate volume. The main limitation of this study is the large proportion of patients that received treatment without reaching BCR. It is plausible that shorter estimated median times would occur at a centre that does not use salvage therapy at such an early state. The time from first detectable PSA to BCR may be lengthy. Our analyses of the predictors of the rate of PSA rise can help determine a personalized approach for patients with a detectable PSA after surgery.

Time from first detectable PSA following radical prostatectomy to biochemical recurrence: A competing risk analysis

PubMed Central

de Boo, Leonora; Pintilie, Melania; Yip, Paul; Baniel, Jack; Fleshner, Neil; Margel, David

2015-01-01

Introduction: In this study, we estimated the time from first detectable prostate-specific antigen (PSA) following radical prostatectomy (RP) to commonly used definitions of biochemical recurrence (BCR). We also identified the predictors of time to BCR. Methods: We identified subjects who underwent a RP and had an undetectable PSA after surgery followed by at least 1 detectable PSA between 2000 and 2011. The primary outcome was time to BCR (PSA ≥0.2 and successive PSA ≥0.2) and prediction of the rate of PSA rise. Outcomes were calculated using a competing risk analysis, with univariable and multivariable Fine and Grey models. We employed a mixed effect model to test clinical predictors that are associated with the rate of PSA rise. Results: The cohort included 376 patients. The median follow-up from surgery was 60.5 months (interquartile range [IQR] 40.8–91.5) and from detectable PSA was 18 months (IQR 11–32). Only 45.74% (n = 172) had PSA values ≥0.2 ng/mL, while 15.16% (n = 57) reached the PSA level of ≥0.4 ng/mL and rising. On multivariable analysis, the values of the first detectable PSA and pathologic Gleason grade 8 or higher were consistently independent predictors of time to BCR. In the mixed effect model rate, the PSA rise was associated with time from surgery to first detectable PSA, Gleason score, and prostate volume. The main limitation of this study is the large proportion of patients that received treatment without reaching BCR. It is plausible that shorter estimated median times would occur at a centre that does not use salvage therapy at such an early state. Conclusion: The time from first detectable PSA to BCR may be lengthy. Our analyses of the predictors of the rate of PSA rise can help determine a personalized approach for patients with a detectable PSA after surgery. PMID:25624961