scholarly journals BCR-ABL SH3-SH2 domain mutations in chronic myeloid leukemia patients on imatinib

Blood ◽  
2010 ◽  
Vol 116 (17) ◽  
pp. 3278-3285 ◽  
Author(s):  
Daniel W. Sherbenou ◽  
Oliver Hantschel ◽  
Ines Kaupe ◽  
Stephanie Willis ◽  
Thomas Bumm ◽  
...  

Abstract Point mutations in the kinase domain of BCR-ABL are the most common mechanism of drug resistance in chronic myeloid leukemia (CML) patients treated with ABL kinase inhibitors, including imatinib. It has also been shown in vitro that mutations outside the kinase domain in the neighboring linker, SH2, SH3, and Cap domains can confer imatinib resistance. In the context of ABL, these domains have an autoinhibitory effect on kinase activity, and mutations in this region can activate the enzyme. To determine the frequency and relevance to resistance of regulatory domain mutations in CML patients on imatinib, we screened for such mutations in a cohort of consecutive CML patients with various levels of response. Regulatory domain mutations were detected in 7 of 98 patients, whereas kinase domain mutations were detected in 29. One mutation (T212R) conferred in vitro tyrosine kinase inhibitor resistance and was associated with relapse, whereas most other mutations did not affect drug sensitivity. Mechanistic studies showed that T212R increased the activity of ABL and BCR-ABL and that T212R-induced resistance may be partially the result of stabilization of an active kinase conformation. Regulatory domain mutations are uncommon but may explain resistance in some patients without mutations in the kinase domain.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1934-1934 ◽  
Author(s):  
Simona Soverini ◽  
Alessandra Gnani ◽  
Sabrina Colarossi ◽  
Fausto Castagnetti ◽  
Elisabetta Abruzzese ◽  
...  

Abstract Point mutations in the kinase domain (KD) of the Bcr-Abl gene are generally regarded as the most frequent mechanism of resistance to the tyrosine kinase inhibitor (TKI) imatinib mesylate (IM) in patients (pts) with chronic myeloid leukemia (CML). Nearly all studies, however, have focused mainly on pts with advanced disease, where resistance is most often observed. Nowadays, the great majority of pts on IM are early chronic phase (ECP) pts receiving IM as front-line treatment. If, on one hand, the IRIS study demonstrated that response rates are high and relapse is infrequent in ECP, on the other hand we still know very little on the contribution of KD mutations to resistance in this subset of pts. Between January 2005 and July 2007 we analyzed for the presence of Abl KD mutations one hundred and two ECP pts on IM who were referred to our laboratory because their response was defined either as ‘failure’ (n=70 pts) or as ‘suboptimal’ (n=32 pts) according to recently published recommendations (Baccarani et al, Blood 2006). Twenty mutations were detected in 17/70 (24%) pts who failed IM. In particular, mutations were observed in 1/2 pts who showed no hematologic response (HR) at 3 months, 1/10 (10%) pts who showed less than partial cytogenetic response (PCgR) at 12 months, 4/25 (16%) pts who showed less than complete cytogenetic response (CCgR) at 18 months, 6/23 (26%) pts who lost CCgR, 5/10 (50%) pts who lost HR. Mutations were M244V (n=2), G250E (n=1), Y253H (n=4), E255K (n=1), T277A (n=1), E279K (n=1), F311I (n=1), T315I (n=1), M351T (n=3), E355D (n=1), F359V (n=1), H396R (n=3). In 7 pts who progressed to accelerated or blastic phase shortly after, four had mutations: Y253H (n=2 pts), E255K (n=1 pt) and T315I (n=1 pt). Four mutations were detected in 4/32 (13%) pts who had a suboptimal response to IM. In particular, a mutation was observed in 1/11 (9%) pts who showed less than PCgR at 6 months and in 3/21 (14%) pts who showed less than CCgR at 12 months. Mutations were E255K, F317L, M351T, F359V. In both groups no correlation was observed between likelihood of mutation selection and Sokal risk score. We conclude that in ECP pts who receive IM as front-line treatment Abl KD mutations are not the major mechanism of drug-resistance, probably because mutations tend to accumulate during the natural course of the disease as a result of a progressively increasing genetic instability and are therefore a feature of CML clinical deterioration rather than a phenomenon observed only against a background of IM exposure. Our data highlight the need to find out which is the actual predominant mechanism(s) of resistance acting in the setting of ECP - which now gathers the overwhelming majority of CML pts on IM therapy - as a mandatory step towards the development of effective second-line treatment strategies.


2020 ◽  
Vol 17 (1) ◽  
pp. 48-54
Author(s):  
Reni Widyastuti ◽  
Melva Louisa ◽  
Ikhwan Rinaldi ◽  
Riki Nova ◽  
Instiaty Instiaty ◽  
...  

Background: Imatinib mesylate is the first tyrosine kinase inhibitor approved for chronic myeloid leukemia (CML) therapy. Imatinib is an effective drug. However, previous studies have shown that about 20-30% of patients eventually would develop resistance to imatinib. Approximately 40% of imatinib resistance is associated with BCRABL kinase domain mutation. One of the most common and serious variations account for imatinib response is T315I of ABL1 gene. Objective: The study aimed to examine the association of T315I mutation with the ABL1 gene and its relation to major molecular response (MMR) achievement in CML patients. This study also examined other mutations adjacent to T315I, i.e., F311I, F317L, and different possible variations in the ABL1 gene. Methods: This was a cross-sectional study on Indonesian CML patients in chronic phase. We analyzed 120 blood samples from patients in chronic phase who have received imatinib mesylate (IM) for ≥12 months. Results: There were no T315I, F311I, and F317L mutations found in this study. However, we found another variation, which was 36 substitutions from A to G at position 163816 of ABL1 gene (according to NG_012034.1). Conclusions: We found no T315I, F311I, and F317L mutations in this study. Our findings suggest that there might be other factors that influenced the MMR achievement in our study patients. However, there were 36 substitutions from A to G at position 163.816 (according to NG_012034.1) that needed further examination to explore the significance of this mutation in clinical practice.


2004 ◽  
Vol 50 (7) ◽  
pp. 1205-1213 ◽  
Author(s):  
Simona Soverini ◽  
Giovanni Martinelli ◽  
Marilina Amabile ◽  
Angela Poerio ◽  
Michele Bianchini ◽  
...  

Abstract Background: Despite the efficacy of the BCR-ABL tyrosine kinase inhibitor Imatinib mesylate for the treatment of chronic myeloid leukemia (CML), resistance has been observed in a proportion of cases, especially those with advanced stages of the disease. Point mutations within the ABL kinase domain are emerging as the most frequent mechanism for reactivation of kinase activity within the leukemic clone. Methods: We developed a denaturing-HPLC (D-HPLC)-based assay for screening for ABL point mutations. For each sample, two partially overlapping fragments of 393 and 482 bp corresponding to the kinase domain were amplified by nested reverse transcription-PCR and analyzed under selected temperature and acetonitrile gradient conditions. Fifty-one bone marrow and/or peripheral blood specimens from 27 CML patients who showed cytogenetic resistance to Imatinib were screened in parallel by D-HPLC and by direct sequencing. Results: In 12 of 27 (44%) patients, D-HPLC showed an abnormal elution profile suggesting the presence of a nucleotide change. Direct sequencing confirmed the presence of a point mutation in all cases. Conversely, all samples scored as wild type by D-HPLC showed no evidence of mutations by direct sequencing. In two cases, novel amino acid substitutions at codons already known for being hot-spots of mutation were identified (F311I and E355D). Conclusions: The proposed D-HPLC-based assay is highly specific and at least as sensitive as sequencing; with respect to the latter, it provides a much faster and less expensive semiautomated system for mutational screening. It may therefore potentially be a valuable tool for regular, large-scale testing of patients undergoing Imatinib treatment.


2021 ◽  
pp. 1187-1193
Author(s):  
Fisihatsion Tadesse ◽  
Getahun Asres ◽  
Abdulaziz Abubeker ◽  
Amha Gebremedhin ◽  
Jerald Radich

PURPOSE Despite the successes achieved in chronic myeloid leukemia (CML) with tyrosine kinase inhibitor (TKI) therapy, resistance remains an obstacle. The most common mechanism of resistance is the acquisition of a point mutation in the BCR-ABL kinase domain. Few studies have reported African patients with CML in regard to such mutations. We here report the types of BCR-ABL mutations in Ethiopian imatinib-resistant patients with CML and their outcome. PATIENTS AND METHODS Patients with CML with a diagnosis of imatinib resistance who were tested for BCR-ABL mutation between 2014 and September 2019 were included. RESULTS A total of 962 cases of CML on imatinib therapy were reviewed and 164 cases of failure were found. Of these, only 31 cases (19%) had mutation analysis performed. Most cases (94%) were secondary failures. At the time of CML diagnosis, the median age was 33 years and the majority presented with features of advanced-phase disease. Of the 31 patients, 22 mutations were found (65%). The types of mutations detected were as follows: non–P-loop mutations 36% (11), P-loop mutations 13% (four), and alternatively spliced BCR-ABL variants 23% (seven). The splice variant frequently detected was BCR-ABL35INS (20%). Twenty-six of the 31 patients (84%) were switched to second-line TKIs, whereas in four patients (13%), imatinib dose escalation was done. Overall, the outcome revealed that 16 patients (52%) were alive with complete hematologic response, whereas 12 patients (39%) had died. All patients who expressed BCR-ABL135INS were treated with second-line TKIs, and two of them (33%) had died because of disease progression. CONCLUSION In Ethiopia, CML affects the young and point mutations were frequently detected in imatinib-resistant patients. BCR-ABL1 35INS was also prevalent and associated with disease progression.


Author(s):  
M. V. Borisevich ◽  
T. V. Savitskaya

Chronic myeloid leukemia (CML) in children is rare, less than 3 % of all cases of leukemia in pediatric practice. Along with the successes achieved in the treatment of CML with imatinib, it’s necessary to study of molecular factors in predicting resistance to therapy. According to the literature, about 30 % of adult patients with imatinib resistance have point mutations in the kinase domain of BCR-ABL1 gene. The number of reports about mutation spectrum of the BCR-ABL1 gene in children with resistant forms of CML is limited. This article describes the clinical case of secondary resistance to imatinib in a 15-year-old girl with the F359C mutation of BCR-ABL1 gene and a review of the literature.


2009 ◽  
Vol 02 ◽  
pp. 30
Author(s):  
Ronan Swords ◽  
Kevin Kelly ◽  
Francis J Giles ◽  
◽  
◽  
...  

Chronic myeloid leukemia (CML) results from a single translocation that produces the BCR–ABL fusion oncogene, which is detectable in virtually all patients. Imatinib mesylate has radically changed the outlook for newly diagnosed patients and represents the current standard of care for this disorder. While most patients do well well with imatinib upfront, a minority of patients do not. In addition, this therapy offers little benefit for patients with advanced-phase disease. Several mechanisms underlie imatinib failure, point mutations within the Abelson tyrosine (ABL) kinase domain being the most significant of these. The development of novel agents designed to overcome imatinib resistance led to the creation of the high-affinity BCR-ABL inhibitor nilotinib. The purpose of this article is to summarize the pre-clinical and clinical data on nilotinib in patients with CML who have failed prior therapy with imatinib or dasatinib.


Blood ◽  
2011 ◽  
Vol 118 (19) ◽  
pp. 5250-5254 ◽  
Author(s):  
Thomas O'Hare ◽  
Matthew S. Zabriskie ◽  
Christopher A. Eide ◽  
Anupriya Agarwal ◽  
Lauren T. Adrian ◽  
...  

Abstract Chronic myeloid leukemia is effectively treated with imatinib, but reactivation of BCR-ABL frequently occurs through acquisition of kinase domain mutations. The additional approved ABL tyrosine kinase inhibitors (TKIs) nilotinib and dasatinib, along with investigational TKIs such as ponatinib (AP24534) and DCC-2036, support the possibility that mutation-mediated resistance in chronic myeloid leukemia can be fully controlled; however, the molecular events underlying resistance in patients lacking BCR-ABL point mutations are largely unknown. We previously reported on an insertion/truncation mutant, BCR-ABL35INS, in which structural integrity of the kinase domain is compromised and all ABL sequence beyond the kinase domain is eliminated. Although we speculated that BCR-ABL35INS is kinase-inactive, recent reports propose this mutant contributes to ABL TKI resistance. We present cell-based and biochemical evidence establishing that BCR-ABL35INS is kinase-inactive and does not contribute to TKI resistance, and we find that detection of BCR-ABL35INS does not consistently track with or explain resistance in clinical samples from chronic myeloid leukemia patients.


Blood ◽  
2007 ◽  
Vol 110 (7) ◽  
pp. 2242-2249 ◽  
Author(s):  
Thomas O'Hare ◽  
Christopher A. Eide ◽  
Michael W. N. Deininger

Mutations in the kinase domain (KD) of BCR-ABL are the most prevalent mechanism of acquired imatinib resistance in patients with chronic myeloid leukemia (CML). Here we examine predisposing factors underlying acquisition of KD mutations, evidence for acquisition of mutations before and during therapy, and whether the detection of a KD mutation universally implies resistance. We also provide a perspective on how the second-line Abl inhibitors dasatinib and nilotinib are faring in the treatment of imatinib-resistant CML, especially in relation to specific KD mutations. We discuss the growing importance of the multi-inhibitor–resistant 315T>I mutant and the therapeutic potential that a 315T>I inhibitor would have. Last, we assess the potential of Abl kinase inhibitor combinations to induce stable responses even in advanced CML and interpret the emerging data in the context of CML pathogenesis.


2016 ◽  
Vol 8 ◽  
pp. 2016016
Author(s):  
Massimo Breccia ◽  
Gioia Colafigli ◽  
Luisa Quattrocchi ◽  
Elisabetta Abruzzese ◽  
Giuliana Alimena

Ponatinib a third generation tyrosine kinase inhibitor, has been approved for all phases of disease in CML. In advanced phase, has been confirmed with a good efficacy in all type of resistance, including T315I kinase domain mutation. We here report activity of the drug in advanced phase with extramedullary localization.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2004-2004 ◽  
Author(s):  
Giovanni Martinelli ◽  
Alberto M. Martelli ◽  
Tiziana Grafone ◽  
Irina Mantovani ◽  
Alessandra Cappellini ◽  
...  

Abstract Imatinib mesylate (Novartis Pharma), an inhibitor of the bcr/abl tyrosine kinase, has rapidly become the first-line therapy for CML. Imatinib has proved remarkably effective at reducing the number of leukaemia cells in individual CML patients and promises to prolong life substantially in comparison with earlier treatments. However, in patients in advanced phases of the disease, the development of resistance to this drug is a frequent setback. Therefore, new inhibitors of bcr/abl are needed. Very recently, a new bcr/abl inhibitor, AMN107 (Novartis Pharma), has been developed. We have tested AMN107 on human leukaemia cell lines and on blasts isolated from imatinib-resistant CML patients. After a 24 h incubation, AMN107 (10 nM) blocked K562 cells in the G1 phase of the cell cycle. To obtain the same effect with imatinib, a 200 nM concentration was required. AMN107 had no affect on cell cycle progression of bcr/abl-negative cell lines such as HL60 and NB4, even if the concentration was raised to 500 nM. After 48 h incubation, AMN107 (10 nM) was capable of inducing a massive apoptosis of K562 cells whereas, once again, 200 nM imatinib was required to obtain the same effect. Western blot analysis with phosphospecific antibodies revealed that in K562 cells AMN107 (50 nM) markedly down-regulated autophosphorylation of bcr/abl Tyr177 and Tyr412, whereas autophosphorylation of Thr735 was unaffected. In contrast, imatinib even if used at 200 nM, did not diminish phosphorylation of either bcr/abl Tyr177 or Tyr412. This finding seems particularly important because recent evidence has demonstrated that the signalling pathway emanating from Tyr177 plays a major role in the pathogenesis of CML. Indeed, phosphorylated Tyr177 forms a high-affinity binding site for the SH2 domain of the adapter Grb2. The main effectors of Grb2 are Sos and Ras, however Grb2 also recruits the scaffolding adapter protein Gab2 to bcr/abl via a Grb2-Gab2 complex, which results in activation of phosphoinositide 3-kinase (PI3K)/Akt and Erk signalling networks. Consistently, we found by immunoprecipitation decreased levels of bcr/abl-associated Gab2, Grab2, and p85 regulatory subunit of PI3K in AMN107-treated cells. AMN107 treatment of K562 cells also caused a reduction of STAT5, cCBL, CRKL, and Akt phosphorylation levels, as well as Bcl-XL expression. AMN107 (5 μM for 24h) significantly increased the apoptosis rate of CML blasts isolated from patients resistant to imatinib. Therefore, AMN107 might represent a new bcr/abl selective inhibitor useful for overcoming imatinib resistance.


Sign in / Sign up

Export Citation Format

Share Document