Application of FASTTM Fragment-Based Lead Discovery and Structure-Guided Design to Discovery of Small Molecule Inhibitors of BCR-ABL Tyrosine Kinase Active Against the T315I Imatinib-Resistant Mutant.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 698-698 ◽  
Author(s):  
Stephen K. Burley
Keyword(s):  
Tyrosine Kinase ◽  
Fusion Gene ◽  
Clinical Success ◽  
Philadelphia Chromosome ◽  
Myelogenous Leukemia ◽  
Wild Type ◽  
Lead Discovery ◽  
Abl Tyrosine Kinase ◽  
Imatinib Resistant

Abstract The Philadelphia chromosome translocation creates a BCR-ABL fusion gene that encodes a constitutively active BCR-ABL tyrosine kinase, which gives rise to chronic myelogenous leukemia (CML). The clinical success of imatinib (Gleevec) demonstrated that BCR-ABL tyrosine kinase inhibitors can provide effective treatment for CML. However, some CML patients treated with imatinib develop resistance leading to disease progression. The majority of resistance is due to point mutations in BCR-ABL, which give rise to active mutant enzymes that are insensitive to imatinib. In all, ~30 imatinib-resistant BCR-ABL mutants have been identified in clinical isolates. The T315I mutant represents ~20% of clinically observed mutations, making it one of the most common causes of resistance. Second-generation BCR-ABL inhibitors, including AMN-107 and BMS-354825, inhibit many of the clinically relevant mutants but not T315I. Mutant T315I BCR-ABL is, therefore, an important and challenging target for discovery of CML therapeutics. We have applied a proprietary X-ray crystallographic fragment-based lead discovery platform (FASTTM) and structure-guided lead optimization to identify potent inhibitors of wild-type BCR-ABL and the four most common mutants, including T315I. Our lead discovery efforts yielded five chemical series that inhibit both wild-type (WT) and T315I BCR-ABL. Compounds in our most advanced lead series potently inhibit proliferation of K562 cells and Ba/F3 cells with WT BCR-ABL and the four major clinically relevant BCR-ABL mutations (T315I, E255K, M351T, Y253F; see below). Further details describing in vitro and in vivo profiling of these novel BCR-ABL T315I inhibitors will be presented. Ba/F3 cell proliferation for BCR-ABL Inhibitors (EC50, nM) BCR-ABL Form Imatinib AMN-107 BMS-354825 SGX-70430 WT 790 33 12 11 T315I > 10000 > 10000 > 10000 21 Y253F 5700 370 8 334 E255K 8300 350 7 77 M351T 2000 38 28 15 Control Assay Ba/F3 (T315I) + IL3 > 10000 > 10000 > 10000 > 10000

Efficacy of STI571, an Abl tyrosine kinase inhibitor, in conjunction with other antileukemic agents against Bcr-Abl–positive cells

Blood ◽  
2000 ◽  
Vol 96 (9) ◽  
pp. 3195-3199 ◽  
Author(s):  
J. Tyler Thiesing ◽  
Sayuri Ohno-Jones ◽  
Kathryn S. Kolibaba ◽  
Brian J. Druker
Keyword(s):  
Clinical Trials ◽  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitor ◽  
Kinase Inhibitor ◽  
Single Agent ◽  
Myelogenous Leukemia ◽  
Hematopoietic Stem ◽  
Abl Tyrosine Kinase ◽  
Abl Tyrosine Kinase Inhibitor

Abstract Chronic myelogenous leukemia (CML), a malignancy of a hematopoietic stem cell, is caused by the Bcr-Abl tyrosine kinase. STI571(formerly CGP 57148B), an Abl tyrosine kinase inhibitor, has specific in vitro antileukemic activity against Bcr-Abl–positive cells and is currently in Phase II clinical trials. As it is likely that resistance to a single agent would be observed, combinations of STI571 with other antileukemic agents have been evaluated for activity against Bcr-Abl–positive cell lines and in colony-forming assays in vitro. The specific antileukemic agents tested included several agents currently used for the treatment of CML: interferon-alpha (IFN), hydroxyurea (HU), daunorubicin (DNR), and cytosine arabinoside (Ara-C). In proliferation assays that use Bcr-Abl–expressing cells lines, the combination of STI571 with IFN, DNR, and Ara-C showed additive or synergistic effects, whereas the combination of STI571 and HU demonstrated antagonistic effects. However, in colony-forming assays that use CML patient samples, all combinations showed increased antiproliferative effects as compared with STI571 alone. These data indicate that combinations of STI571 with IFN, DNR, or Ara-C may be more useful than STI571 alone in the treatment of CML and suggest consideration of clinical trials of these combinations.

scholarly journals Multi-unit ribozyme-mediated cleavage of bcr-abl mRNA in myeloid leukemias

Blood ◽  
1995 ◽  
Vol 85 (8) ◽  
pp. 2162-2170 ◽  
Author(s):  
LH Leopold ◽  
SK Shore ◽  
TA Newkirk ◽  
RM Reddy ◽  
EP Reddy
Keyword(s):  
Chronic Myelogenous Leukemia ◽  
Fusion Gene ◽  
Folate Receptor ◽  
Philadelphia Chromosome ◽  
Chromosome 9 ◽  
Myelogenous Leukemia ◽  
Myeloid Leukemias ◽  
Transforming Activity ◽  
Cleavage Reactions

Chronic myelogenous leukemia is characterized by the Philadelphia chromosome, which at the molecular level results from the fusion of the bcr gene on chromosome 22 and the abl gene on chromosome 9. The bcr-abl fusion gene encodes a novel tyrosine kinase with transforming activity. In this study, we have synthesized a multi-unti ribozyme that targets bcr-abl mRNA. In vitro ribozyme cleavage reactions show increased cleavage efficiency of this multi-unit ribozyme compared with single or double ribozymes. The multiunit ribozyme was then transfected into murine myeloblasts transformed with the bcr-abl gene (32D cells). Ribozyme transfection was accomplished either by liposomes or using follic acid-polylysine as a carrier. Multi-unit ribozyme transfection reduced the level of bcr-abl mRNA 3 logs when transfected via folate receptor-mediated uptake into transformed 32D cells. These results suggest that a multi-unit ribozyme could be an effective therapeutic agent for the treatment of Philadelphia chromosome-positive chronic myelogenous leukemia.

Intrinsic Regulation of the Interactions between the SH3 Domain of p85 Subunit of Phosphatidylinositol-3 Kinase and BCR/ABL Oncogenic Tyrosine Kinase.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2961-2961
Author(s):  
Shuyue Ren ◽  
Fan Xue ◽  
Jan Feng ◽  
Tomasz Skorski
Keyword(s):  
Catalytic Activity ◽  
Tyrosine Kinase ◽  
Philadelphia Chromosome ◽  
Sh3 Domain ◽  
Myelogenous Leukemia ◽  
Wild Type ◽  
Phosphatidylinositol 3 Kinase ◽  
Abl Kinase ◽  
Intrinsic Regulation ◽  
Phosphatidylinositol 3

Abstract BCR/ABL fusion tyrosine kinase is responsible for the initiation and maintenance of the Philadelphia chromosome (Ph1)-positive chronic myelogenous leukemia (CML) and a cohort of acute lymphocytic leukemias (ALL). Our previous studies showed that a signaling protein phosphatidylinositol-3 kinase (PI-3k) is essential for the growth of CML cells, but not of normal hematopoietic cells, and that p85 subunit of PI-3k co-immunoprecipitates with BCR/ABL (Skorski et al., (1995) Blood 86, 726–36; Skorski et al., (1997) Embo J 16, 6151–61; Klejman et al., (2002) Oncogene 21, 5868–76). Therefore, we made an attempt to better characterize the p85 - BCR/ABL interactions. Here we show that SH3 domain of p85 (p85-SH3) pulls-down the p210BCR/ABL kinase from hematopoietic cell lysates. In addition, we characterize the p85-SH3 mutants, which abrogate or enhance this interaction. The results of pull-down assays of the p85-SH3 mutants seem to support the assumption that p85-SH3 interacts with the BCR/ABL protein network via the proline-rich (PxxP) region. One of the surprising findings was the enhanced binding affinity of the tyrosine to phenylalanine p85-SH3 domain mutants in comparison to the wild-type p85-SH3. Based on these results we speculate on the capability of p85-SH3 to interact with BCR/ABL and on the p85-SH3 conformational requirements necessary for this reaction. PxxP - binding appears to be required for the interaction of p85-SH3 with BCR/ABL protein complex and activation of the catalytic activity of PI-3k, whereas subsequent BCR/ABL-dependent phosphorylation of the tyrosines may facilitate the release of activated PI-3k from the complex.

CNS-9, a Novel Specific Inhibitor of ABL Tyrosine Kinase Overcomes Resistance Mechanism of Imatinib.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 761-761 ◽  
Author(s):  
Shinya Kimura ◽  
Hidekazu Segawa ◽  
Junya Kuroda ◽  
Takeshi Yuasa ◽  
Taira Maekawa
Keyword(s):  
Tyrosine Kinase ◽  
Growth Inhibition ◽  
Cell Lines ◽  
Nude Mice ◽  
Philadelphia Chromosome ◽  
Specific Inhibitor ◽  
Vitro Assay ◽  
Abl Tyrosine Kinase

Abstract Imatinib mesylate (also known as STI-571 and Gleevec) has drastically changed the treatment of Philadelphia chromosome positive (Ph+) leukemias. However, the resistance to imatinib has frequently been reported, particularly in patients with advanced-stage disease. A novel orally bioavailable inhibitor of the ABL tyrosine kinase (TK) named CNS-9 was developed from the 2-(phenylamino)pyrimidine class to overcome resistance mechanisms of imatinib. Inhibition of TK phosphorylation (IC50) on wild type (wt) BCR/ABL in 293T cell line by CNS-9 was 22nM, which was 2-log more potent than imatinib. Importantly, CNS-9 inhibited TK phosphorylation of E255K mutant BCR/ABL with IC50 of 98nM, while imatinib could not inhibit it with clinically relevant concentration. The T315I mutant BCR/ABL protein was resistant to CNS-9 and imatinib. CNS-9 also inhibited TK phosphorylation of platelet-derived growth factor receptor (PDGFR) or c-Kit pathways at the very similar observed IC50s when compared with imatinib, in spite of significant higher potency against ABL. The ability of CNS-9 in vitro to inhibit 101 TK molecules was assayed by KinaseProfilerTM (Upstate), showing also more specific inhibitory activity against ABL than imatinib. The growth of BCR/ABL-positive cell lines K562, KU812, BaF3 harboring wt BCR/ABL (BaF3/wt) and E255K (BaF3/E255K) was inhibited by CNS-9 with IC50 of 5, 3, 17, and 110nM, respectively (Table 1). Generally, CNS-9 was 20 to 30-fold more potent on the growth inhibition than imatinib in these same cell lines. We next investigated the in vivo effect on the leukemic growth inhibition of CNS-9. Nude mice were injected subcutaneously with 3x107 KU812 (wt BCR/ABL) on Day 0. CNS-9 or imatinib were orally administrated twice a day from Day 7 to Day 18. The dosages of CNS-9 and imatinib, which inhibited completely tumor growth were 20mg/kg/day and 200mg/kg/day, respectively, indicating that CNS-9 is 10-fold potent than imatinib in vivo. To examine the in vivo effect of CNS-9 against mutant BCR/ABL, BaF3/wt, BaF3/E255K or BaF3/T315I were engrafted to nude mice and treated with CNS-9 or imatinib. CNS-9 was also 10-fold potent than imatinib against BaF3/wt. Intriguingly, mice harboring BaF3/wt or BaF3/E255K showed significantly prolonged survival when treated with CNS-9. Consistent with in vitro assay, CNS-9 had no effect on T315I, and imatinib was not effective against both E255K and T315I. In conclusion, CNS-9 is substantially more inhibitory and more specifically than imatinib toward BCR/ABL-dependent cell growth both in vitro and in vivo Moreover, CNS-9 may be effective for leukemia patients whose leukemic cells harbor E255K mutant. The efficacy and safety of CNS-9 for Ph+ leukemias should be verified in early phase clinical trials. The IC50s values of leukemic cell lines for CNS-9 and imatinib CNS-9 (nM) imatinib (nM) K562 p210 wt BCR/ABL 5 130 KU812 p210 wt BCR/ABL 3 67 U937 BCR/ABL (−) >1000 >1000 BaF3 p190 wt BCR/ABL 17 360 BaF3 p190 E255K BCR/ABL 110 >1000 BaF3 p190 T315I BCR/ABL >1000 >1000

Rhogtpase RAC2 Is Required for In Vivo Transformation Activity by P210 Bcr-Abl Fusion Oncogene.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 717-717
Author(s):  
Nithya Krishnan ◽  
Jeff R. Bailey ◽  
Victoria Summey-Harner ◽  
Claudio Brunstein ◽  
Catherine M. Verfaillie ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Philadelphia Chromosome ◽  
Protein Domain ◽  
Myelogenous Leukemia ◽  
Wild Type ◽  
Hematopoietic Stem ◽  
Cell Functions ◽  
Empty Vector

Abstract Bcr-Abl, the translocation product of the Philadelphia chromosome implicated in human chronic myelogenous leukemia (CML), is a kinase affecting hematopoietic stem cell (HSC) behavior with respect to proliferation, apoptosis, adhesion and migration. Rho GTPases, particularly the Rac subfamily, have been shown to regulate these same cell functions in normal HSC and also regulate gene expression in many mammalian cells. BCR contains a “GTPase-activating protein” domain and a guanine nucleotide exchange domain, the latter or which is preserved in p210 Bcr-Abl. Since HSC functions regulated by Bcr-Abl and Rac are similar, we studied the potential involvement of Rac activation in Bcr-Abl signaling cascade. Human CML samples demonstrate baseline activation of Rac proteins that is reversed by in vitro treatment with STI571. To study the specific involvement of Rac2, we used a gene targeted mouse model with Rac2 null bone marrow. Using retovirus-mediated gene transfer, we introduced p210 Bcr-Abl in the MSCV vector into wild-type or Rac2−/− HSC/P and studied the behavior of these cells in vitro and in vivo. Irradiated recipient mice injected with LDBM cells transduced with p210 developed a uniformly fatal myeloproliferative syndrome (Median survival: 45 days, N=12), while mice injected with p210 transduced Rac2−/− LDBM cells (N=12, 2 independent exp.) had 100% survival and no development of leukocytosis, splenomegaly or organ infiltration of hematopoietic cells. These data suggest that Rac GTPases are critical for the transformation of HSC by Bcr-Abl and provide an additional therapeutic target for intervention in CML. WILD TYPE Rac 2 −/− Empty Vector MSCV-p210 Empty vector MSCV-p210 *p < 0.01 vs WT-MIEG3, **p< 0.01 vs WT-p210 bcr-abl. Proliferation (CPM) Medium 562 ± 278 16,207± 1605* 819.7 ± 363 3,135.5 ± 498** SCF (100ng/ml) 856 ± 187 23,226 ± 2203* 853.7 ± 524 3,756.8 ± 207** Cytokines (SCF, GCSF, MGDF) 8011± 1412 42,711± 13393* 4833 ±1019 3,614.5 ± 1982** Migration (%) Fibronectin 7 ± 0.4 38 ± 1.9* 0.4 ± 0.0 0.8 ± 0.1** SDF-1α 30 ±2.8 13 ±1.1* 0.5 ± 0.0 0.6 ± 0.0** Adhesion (% ) Fibronectin 76± 2.9 40 ±3* 4 ±0.4 10 ±0.1 **

Jak2: A Potential Therapeutic Target for Chronic Myelogenous Leukemia (CML).

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2121-2121
Author(s):  
Ajoy K. Samanta ◽  
Hui Lin ◽  
Tong Sun ◽  
Hagop Kantarjian ◽  
Ralph B. Arlinghaus
Keyword(s):  
Tyrosine Kinase ◽  
Cell Lines ◽  
Therapeutic Target ◽  
Philadelphia Chromosome ◽  
Chronic Phase ◽  
Myelogenous Leukemia ◽  
Leukemia Cells ◽  
Imatinib Treatment ◽  
Potential Therapeutic Target ◽  
Imatinib Resistant

Abstract In most CML patients Bcr-Abl, a constitutively active tyrosine kinase derived from the Philadelphia chromosome, is highly expressed and is the causative factor in most CML patients. Imatinib mesylate, an inhibitor of the Bcr-Abl kinase, is a very effective drug for treatment of CML. However in some CML patients, drug resistance develops and the patients relapse. Thus, alternative drug targets need to be identified. We have shown that Bcr-Abl activates its downstream target, the Jak2 tyrosine kinase, leading to the enhancement of c-Myc expression (Xie et al. Oncogene21: 7137, 2002; Samanta et al. Cancer Res.66: 6468, 2006). Our recent studies showed that Bcr-Abl activated the transcriptional factor NF-kB through Jak2, which in turn activated c-Myc transcription. Jak2 also activated Akt, which increased c-Myc protein levels by inhibiting GSK3. Addition of AG490, an inhibitor of the Jak2 kinase, prevented enhanced expression of c-Myc and caused induction of apoptosis in BCR-ABL+ leukemia cells. Immunoprecipitation experiments showed that Bcr-Abl is associated with a cluster of signaling proteins including Jak2, Gab2, Akt and GSK3b. Treatment of CML cell lines and mouse BCR-ABL+ 32D cells (myeloid lineage) with the either Jak2 siRNA or the Jak2 kinase inhibitor AG490 caused inhibition of pTyr Gab2 formation, pSer Akt formation and the activation of NFkB. Of interest, treatment of BCR-ABL+ 32 D cells with IL-3 reversed the apoptotic effects of imatinib by activation of Jak2 even though Bcr-Abl was inhibited. Importantly, mouse BaF3 hematopoietic cells expressing the T315I and E255K imatinib-resistant mutants of BCR-ABL underwent apoptosis upon exposure to either the Jak2 inhibitor AG490 or siRNA for Jak2, yet were resistant to imatinib. Cells from a number of CML patients (including six chronic phase, one accelerated phase, and two blast crisis patients who failed imatinib treatment) were induced to enter apoptosis upon treatment with AG490, whereas normal samples were not affected by AG490. Further analysis of imatinib resistant Bcr-Abl cell lines showed that transfection of the cells with Jak2 specific siRNA or by treating the cells with AG490 reduced levels of pLyn, pAkt, c-Myc and pGSK3 level compared to untreated cells. Transfection of Lyn specific siRNA into K562 and 32Dp210 cells resulted in down-regulation of pGab2, pAkt, pGsk3 and c-Myc, but did not alter pJak2 levels; this result indicates that pLyn is downstream of Jak2 but upstream of Gab2, pAkt, pGSK3 in BCR-ABL+ leukemia cells. We hypothesize that Jak2 activation of Lyn tyrosine kinase in BCR-ABL+ leukemia cells leads to tyrosine phosphorylation of the YxxM motif of Gab2, which activates the PI-3 kinase-Akt pathway. In conclusion, since inactivation of Jak2 inhibits many of the critical oncogenic targets of Bcr-Abl (resulting in apoptosis induction), we propose that Jak2 is a potential therapeutic target for CML, in both imatinib sensitive and imatinib resistant patients.

Nilotinib (formerly AMN107), a highly selective BCR-ABL tyrosine kinase inhibitor, is effective in patients with Philadelphia chromosome–positive chronic myelogenous leukemia in chronic phase following imatinib resistance and intolerance

Blood ◽  
2007 ◽  
Vol 110 (10) ◽  
pp. 3540-3546 ◽  
Author(s):  
Hagop M. Kantarjian ◽  
Francis Giles ◽  
Norbert Gattermann ◽  
Kapil Bhalla ◽  
Giuliana Alimena ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitor ◽  
Kinase Inhibitor ◽  
Philadelphia Chromosome ◽  
Chronic Phase ◽  
Myelogenous Leukemia ◽  
Imatinib Resistance ◽  
Abl Tyrosine Kinase ◽  
Abl Tyrosine Kinase Inhibitor ◽  
Philadelphia Chromosome Positive

Abstract Nilotinib, an orally bioavailable, selective Bcr-Abl tyrosine kinase inhibitor, is 30-fold more potent than imatinib in pre-clinical models, and overcomes most imatinib resistant BCR-ABL mutations. In this phase 2 open-label study, 400 mg nilotinib was administered orally twice daily to 280 patients with Philadelphia chromosome–positive (Ph+) chronic myeloid leukemia in chronic phase (CML-CP) after imatinib failure or intolerance. Patients had at least 6 months of follow-up and were evaluated for hematologic and cytogenetic responses, as well as for safety and overall survival. At 6 months, the rate of major cytogenetic response (Ph ≤ 35%) was 48%: complete (Ph = 0%) in 31%, and partial (Ph = 1%-35%) in 16%. The estimated survival at 12 months was 95%. Nilotinib was effective in patients harboring BCR-ABL mutations associated with imatinib resistance (except T315I), and also in patients with a resistance mechanism independent of BCR-ABL mutations. Adverse events were mostly mild to moderate, and there was minimal cross-intolerance with imatinib. Grades 3 to 4 neutropenia and thrombocytopenia were observed in 29% of patients; pleural or pericardial effusions were observed in 1% (none were severe). In summary, nilotinib is highly active and safe in patients with CML-CP after imatinib failure or intolerance. This clinical trial is registered at http://clinicaltrials.gov as ID no. NCT00109707.

scholarly journals Nilotinib (formerly AMN107), a highly selective BCR-ABL tyrosine kinase inhibitor, is active in patients with imatinib-resistant or -intolerant accelerated-phase chronic myelogenous leukemia

Blood ◽  
2008 ◽  
Vol 111 (4) ◽  
pp. 1834-1839 ◽  
Author(s):  
Philipp le Coutre ◽  
Oliver G. Ottmann ◽  
Francis Giles ◽  
Dong-Wook Kim ◽  
Jorge Cortes ◽  
...  
Keyword(s):  
Adverse Events ◽  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitor ◽  
Chronic Myelogenous Leukemia ◽  
Kinase Inhibitor ◽  
Myelogenous Leukemia ◽  
Abl Tyrosine Kinase ◽  
Imatinib Resistant ◽  
Abl Tyrosine Kinase Inhibitor ◽  
Grade 3

Patients with imatinib-resistant or -intolerant accelerated-phase chronic myelogenous leukemia (CML-AP) have very limited therapeutic options. Nilotinib is a highly selective BCR-ABL tyrosine kinase inhibitor. This phase 2 trial was designed to characterize the efficacy and safety of nilotinib (400 mg twice daily) in this patient population with hematologic response (HR) as primary efficacy endpoint. A total of 119 patients were enrolled and had a median duration of treatment of 202 days (range, 2–611 days). An HR was observed in 56 patients (47%; 95% confidence interval [CI], 38%-56%). Major cytogenetic response (MCyR) was observed in 35 patients (29%; 95% CI, 21%-39%). The median duration of HR has not been reached. Overall survival rate among the 119 patients after 12 months of follow-up was 79% (95% CI, 70%-87%). Nonhematologic adverse events were mostly mild to moderate. Severe peripheral edema and pleural effusions were not observed. The most common grade 3 or higher hematologic adverse events were thrombocytopenia (35%) and neutropenia (21%). Grade 3 or higher bilirubin and lipase elevations occurred in 9% and 18% of patients, respectively, resulting in treatment discontinuation in one patient. In conclusion, nilotinib is an effective and well-tolerated treatment in imatinib-resistant and -intolerant CML-AP. This trial is registered at www.clinicaltrials.gov as NCT00384228.

scholarly journals The Discovery of Novel BCR-ABL Tyrosine Kinase Inhibitors Using a Pharmacophore Modeling and Virtual Screening Approach

2021 ◽  
Vol 9 ◽  
Author(s):  
Ting-Ting Huang ◽  
Xin Wang ◽  
Shao-Jia Qiang ◽  
Zhen-Nan Zhao ◽  
Zhuo-Xun Wu ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitors ◽  
Kinase Inhibitors ◽  
Pharmacophore Modeling ◽  
Myelogenous Leukemia ◽  
Lipinski’S Rule ◽  
Abl Tyrosine Kinase ◽  
Pharmacophore Models

Chronic myelogenous leukemia (CML) typically results from a reciprocal translocation between chromosomes 9 and 22 to produce the bcr-abl oncogene that when translated, yields the p210 BCR-ABL protein in more than 90% of all CML patients. This protein has constitutive tyrosine kinase activity that activates numerous downstream pathways that ultimately produces uncontrolled myeloid proliferation. Although the use of the BCR-ABL tyrosine kinase inhibitors (TKIs), such as imatinib, nilotinib, dasatinib, bosutinib, and ponatinib have increased the overall survival of CML patients, their use is limited by drug resistance and severe adverse effects. Therefore, there is the need to develop novel compounds that can overcome these problems that limit the use of these drugs. Therefore, in this study, we sought to find novel compounds using Hypogen and Hiphip pharmacophore models based on the structures of clinically approved BCR-ABL TKIs. We also used optimal pharmacophore models such as three-dimensional queries to screen the ZINC database to search for potential BCR-ABL inhibitors. The hit compounds were further screened using Lipinski’s rule of five, ADMET and molecular docking, and the efficacy of the hit compounds was evaluated. Our in vitro results indicated that compound ZINC21710815 significantly inhibited the proliferation of K562, BaF3/WT, and BaF3/T315I leukemia cells by inducing cell cycle arrest. The compound ZINC21710815 decreased the expression of p-BCR-ABL, STAT5, and Crkl and produced apoptosis and autophagy. Our results suggest that ZINC21710815 may be a potential BCR-ABL inhibitor that should undergo in vivo evaluation.

Detection of c-abl tyrosine kinase activity in vitro permits direct comparison of normal and altered abl gene products

1985 ◽  
Vol 5 (11) ◽  
pp. 3116-3123
Author(s):  
J B Konopka ◽  
O N Witte
Keyword(s):  
Tyrosine Kinase ◽  
Kinase Activity ◽  
Myelogenous Leukemia ◽  
Gene Products ◽  
Tyrosine Kinase Activity ◽  
Abl Kinase ◽  
Abl Tyrosine Kinase ◽  
Assay Conditions

The v-abl transforming protein P160v-abl and the P210c-abl gene product of the translocated c-abl gene in Philadelphia chromosome-positive chronic myelogenous leukemia cells have tyrosine-specific protein kinase activity. Under similar assay conditions the normal c-abl gene products, murine P150c-abl and human P145c-abl, lacked detectable kinase activity. Reaction conditions were modified to identify conditions which would permit the detection of c-abl tyrosine kinase activity. It was found that the Formalin-fixed Staphylococcus aureus formerly used for immunoprecipitation inhibits in vitro abl kinase activity. In addition, the sodium dodecyl sulfate and deoxycholate detergents formerly used in the cell lysis buffer were found to decrease recovered abl kinase activity. The discovery of assay conditions for c-abl kinase activity now makes it possible to compare P150c-abl and P145c-abl kinase activity with the altered abl proteins P160v-abl and P210c-abl. Although all of the abl proteins have in vitro tyrosine kinase activity, they differ in the way they utilize themselves as substrates in vitro. Comparison of in vitro and in vivo tyrosine phosphorylation sites of the abl proteins suggests that they function differently in vivo. The development of c-abl kinase assay conditions should be useful in elucidating c-abl function.

Sign in / Sign up

Export Citation Format

Share Document