Resistance to tyrosine kinase inhibitors and novel insights into genomic instability of chronic myeloid leukemia stem cells

2013 ◽  
pp. 126-135
2020 ◽  
Vol 52 (10) ◽  
pp. 1663-1672
Author(s):  
Chun Shik Park ◽  
H. Daniel Lacorazza

Abstract Chronic myeloid leukemia is a hematological cancer driven by the oncoprotein BCR-ABL1, and lifelong treatment with tyrosine kinase inhibitors extends patient survival to nearly the life expectancy of the general population. Despite advances in the development of more potent tyrosine kinase inhibitors to induce a durable deep molecular response, more than half of patients relapse upon treatment discontinuation. This clinical finding supports the paradigm that leukemia stem cells feed the neoplasm, resist tyrosine kinase inhibition, and reactivate upon drug withdrawal depending on the fitness of the patient’s immune surveillance. This concept lends support to the idea that treatment-free remission is not achieved solely with tyrosine kinase inhibitors and that new molecular targets independent of BCR-ABL1 signaling are needed in order to develop adjuvant therapy to more efficiently eradicate the leukemia stem cell population responsible for chemoresistance and relapse. Future efforts must focus on the identification of new targets to support the discovery of potent and safe small molecules able to specifically eradicate the leukemic stem cell population. In this review, we briefly discuss molecular maintenance in leukemia stem cells in chronic myeloid leukemia and provide a more in-depth discussion of the dual-specificity kinase DYRK2, which has been identified as a novel actionable checkpoint in a critical leukemic network. DYRK2 controls the activation of p53 and proteasomal degradation of c-MYC, leading to impaired survival and self-renewal of leukemia stem cells; thus, pharmacological activation of DYRK2 as an adjuvant to standard therapy has the potential to induce treatment-free remission.


2020 ◽  
Vol 90 ◽  
pp. 46-51.e2
Author(s):  
Yosuke Tanaka ◽  
Tsuyoshi Fukushima ◽  
Keiko Mikami ◽  
Keito Adachi ◽  
Tomofusa Fukuyama ◽  
...  

Blood ◽  
2012 ◽  
Vol 119 (18) ◽  
pp. 4253-4263 ◽  
Author(s):  
Margaret Nieborowska-Skorska ◽  
Piotr K. Kopinski ◽  
Regina Ray ◽  
Grazyna Hoser ◽  
Danielle Ngaba ◽  
...  

Abstract Chronic myeloid leukemia in chronic phase (CML-CP) is induced by BCR-ABL1 oncogenic tyrosine kinase. Tyrosine kinase inhibitors eliminate the bulk of CML-CP cells, but fail to eradicate leukemia stem cells (LSCs) and leukemia progenitor cells (LPCs) displaying innate and acquired resistance, respectively. These cells may accumulate genomic instability, leading to disease relapse and/or malignant progression to a fatal blast phase. In the present study, we show that Rac2 GTPase alters mitochondrial membrane potential and electron flow through the mitochondrial respiratory chain complex III (MRC-cIII), thereby generating high levels of reactive oxygen species (ROS) in CML-CP LSCs and primitive LPCs. MRC-cIII–generated ROS promote oxidative DNA damage to trigger genomic instability, resulting in an accumulation of chromosomal aberrations and tyrosine kinase inhibitor–resistant BCR-ABL1 mutants. JAK2(V617F) and FLT3(ITD)–positive polycythemia vera cells and acute myeloid leukemia cells also produce ROS via MRC-cIII. In the present study, inhibition of Rac2 by genetic deletion or a small-molecule inhibitor and down-regulation of mitochondrial ROS by disruption of MRC-cIII, expression of mitochondria-targeted catalase, or addition of ROS-scavenging mitochondria-targeted peptide aptamer reduced genomic instability. We postulate that the Rac2-MRC-cIII pathway triggers ROS-mediated genomic instability in LSCs and primitive LPCs, which could be targeted to prevent the relapse and malignant progression of CML.


2020 ◽  
Vol 7 (2) ◽  
pp. 205-211
Author(s):  
Kaynat Fatima ◽  
Syed Tasleem Raza ◽  
Ale Eba ◽  
Sanchita Srivastava ◽  
Farzana Mahdi

The function of protein kinases is to transfer a γ-phosphate group from ATP to serine, threonine, or tyrosine residues. Many of these kinases are linked to the initiation and development of human cancer. The recent development of small molecule kinase inhibitors for the treatment of different types of cancer in clinical therapy has proven successful. Significantly, after the G-protein-coupled receptors, protein kinases are the second most active category of drug targets. Imatinib mesylate was the first tyrosine kinase inhibitor (TKI), approved for chronic myeloid leukemia (CML) treatment. Imatinib induces appropriate responses in ~60% of patients; with ~20% discontinuing therapy due to sensitivity, and ~20% developing drug resistance. The introduction of newer TKIs such as, nilotinib, dasatinib, bosutinib, and ponatinib has provided patients with multiple options. Such agents are more active, have specific profiles of side effects and are more likely to reach the necessary milestones. First-line treatment decisions must be focused on CML risk, patient preferences and comorbidities. Given the excellent result, half of the patients eventually fail to seek first-line treatment (due to discomfort or resistance), with many of them needing a third or even further therapy lines. In the present review, we will address the role of tyrosine kinase inhibitors in therapy for chronic myeloid leukemia.


2019 ◽  
Vol 4 (1-2) ◽  
pp. 41-45 ◽  
Author(s):  
Takeo Koshida ◽  
Sylvia Wu ◽  
Hitoshi Suzuki ◽  
Rimda Wanchoo ◽  
Vanesa Bijol ◽  
...  

Dasatinib is the second-generation tyrosine kinase inhibitor used in the treatment of chronic myeloid leukemia. Proteinuria has been reported with this agent. We describe two kidney biopsy–proven cases of dasatinib-induced thrombotic microangiopathy that responded to stoppage of dasatinib and using an alternate tyrosine kinase inhibitor. Certain specific tyrosine kinase inhibitors lead to endothelial injury and renal-limited thrombotic microangiopathy. Hematologists and nephrologists need to be familiar with this off-target effect of dasatinib.


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