BACKGROUND: The BCR::ABL1 is a hallmark of chronic myeloid leukemia (CML) and is also found in acute lymphoblastic leukemia (ALL). Most genomic breaks on the BCR side occur in two regions - Major and minor - leading to p210 and p190 fusion proteins, respectively. METHODS: By multiplex long-distance PCR or next-generation sequencing technology we characterized the BCR::ABL1 genomic fusion in 971 patients (adults and children, with CML and ALL: pediatric ALL: n = 353; pediatric CML: n = 197; adult ALL: n = 166; adult CML: n = 255 patients) and designed "Break-App" web tool to allow visualization and various analyses of the breakpoints. Pearson's Chi-Squared test, Kolmogorov-Smirnov test and logistic regression were used for statistical analyses. RESULTS: Detailed analysis showed a non-random distribution of breaks in both BCR regions, whereas ABL1 breaks were distributed more evenly. However, we found a significant difference in the distribution of breaks between CML and ALL. We found no association of breakpoints with any type of interspersed repeats or DNA motifs. With a few exceptions, the primary structure of the fusions suggests non-homologous end joining being responsible for the BCR and ABL1 gene fusions. Analysis of reciprocal ABL1::BCR fusions in 453 patients showed mostly balanced translocations without major deletions or duplications. CONCLUSIONS: Taken together, our data suggest that physical colocalization and chromatin accessibility, which change with the developmental stage of the cell (hence the difference between ALL and CML), are more critical factors influencing breakpoint localization than presence of specific DNA motifs.
- MeSH
- akutní lymfatická leukemie * genetika patologie MeSH
- bcr-abl fúzové proteiny * genetika MeSH
- body zlomu chromozomu * MeSH
- chronická myeloidní leukemie * genetika patologie MeSH
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- dopisy MeSH
Clinical experience with tyrosine kinase inhibitors (TKIs) over the past two decades has shown that, despite the apparent therapeutic benefit, nearly 30% of patients with chronic myelogenous leukemia (CML) display primary resistance or intolerance to TKIs, and approximately 25% of those treated are forced to switch TKIs at least once during therapy due to acquired resistance. Safe and effective treatment modalities targeting leukemic clones that escape TKI therapy could hence be game changers in the professional management of these patients. Here, we aimed to investigate the efficacy of a novel therapeutic oligonucleotide of unconventional design, called ASP210, to reduce BCR-ABL1 mRNA levels in TKI-resistant CML cells, with the assumption of inducing their apoptosis. Imatinib- and dasatinib-resistant sublines of BCR-ABL1-positive MOLM-7 and CML-T1 cells were established and exposed to 0.25 and 2.5 μM ASP210 for 10 days. RT-qPCR showed a remarkable reduction of the target mRNA level by >99% after a single application. Cell viability was monitored daily by trypan blue staining. In response to the lack of driver oncoprotein BCR-ABL1, TKI-resistant CML cells underwent apoptosis regardless of the presence of the clinically relevant T315I mutation by day 5 after redosing with ASP210. The effect was selective for cancer cells, indicating a favorable safety profile for this therapeutic modality. Furthermore, the spontaneous uptake and high intracellular concentrations of ASP210 suggest its potential to be effective at relatively low doses. The present findings suggest that ASP210 is a promising therapeutic avenue for patients with CML who fail to respond to TKI therapy.NEW & NOTEWORTHY Effective treatment modalities targeting leukemic clones that escape tyrosine kinase inhibitor (TKI) therapy could be game changers in the professional management of patients displaying primary resistance, intolerance, or acquired resistance to TKIs. Although delivering authentic innovations today is more complex than ever, we developed a highly potent and safe oligonucleotide-based modality against BCR-ABL1 mRNA named ASP210 that effectively induces cell death in BCR-ABL1-positive TKI-resistant cells while sparing BCR-ABL1-negative healthy cells.
- MeSH
- antitumorózní látky farmakologie MeSH
- apoptóza * účinky léků MeSH
- bcr-abl fúzové proteiny * genetika antagonisté a inhibitory metabolismus MeSH
- chemorezistence * účinky léků MeSH
- chronická myeloidní leukemie * farmakoterapie genetika patologie MeSH
- dasatinib farmakologie MeSH
- imatinib mesylát * farmakologie terapeutické užití MeSH
- inhibitory proteinkinas * farmakologie MeSH
- lidé MeSH
- messenger RNA genetika metabolismus MeSH
- nádorové buněčné linie MeSH
- oligonukleotidy * farmakologie MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- bcr-abl fúzové proteiny genetika MeSH
- blastická krize * genetika farmakoterapie patologie MeSH
- chronická myeloidní leukemie * farmakoterapie genetika patologie MeSH
- imidazoly * terapeutické užití aplikace a dávkování MeSH
- inhibitory proteinkinas terapeutické užití farmakologie MeSH
- lidé MeSH
- mutace * MeSH
- myši MeSH
- niacinamid analogy a deriváty MeSH
- protokoly antitumorózní kombinované chemoterapie terapeutické užití MeSH
- pyrazoly MeSH
- pyridaziny * terapeutické užití aplikace a dávkování MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- dopisy MeSH
Blast phase (BP) of chronic myeloid leukemia (CML) still represents an unmet clinical need with a dismal prognosis. Due to the rarity of the condition and the heterogeneity of the biology and clinical presentation, prospective trials and concise treatment recommendations are lacking. Here we present the analysis of the European LeukemiaNet Blast Phase Registry, an international collection of the clinical presentation, treatment and outcome of blast phases which had been diagnosed in CML patients after 2015. Data reveal the expected heterogeneity of the entity, lacking a clear treatment standard. Outcomes remain dismal, with a median overall survival of 23.8 months (median follow up 27.8 months). Allogeneic stem cell transplantation (alloSCT) increases the rate of deep molecular responses. De novo BP and BP evolving from a previous CML do show slightly different features, suggesting a different biology between the two entities. Data show that outside clinical trials and in a real-world setting treatment of blast phase is individualized according to disease- and patient-related characteristics, with the aim of blast clearance prior to allogeneic stem cell transplantation. AlloSCT should be offered to all patients eligible for this procedure.
- MeSH
- blastická krize * patologie MeSH
- chronická myeloidní leukemie * farmakoterapie patologie terapie mortalita MeSH
- dospělí MeSH
- homologní transplantace MeSH
- inhibitory proteinkinas * terapeutické užití MeSH
- inhibitory tyrosinkinasy MeSH
- lidé středního věku MeSH
- lidé MeSH
- management nemoci MeSH
- míra přežití MeSH
- mladiství MeSH
- mladý dospělý MeSH
- následné studie MeSH
- prognóza MeSH
- registrace * MeSH
- senioři MeSH
- transplantace hematopoetických kmenových buněk metody MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
- MeSH
- chronická myeloidní leukemie farmakoterapie patologie MeSH
- folikulární lymfom terapie MeSH
- hematologie * MeSH
- hormony kůry nadledvin škodlivé účinky terapeutické užití MeSH
- imunoterapie adoptivní MeSH
- inhibitory tyrosinkinasy aplikace a dávkování škodlivé účinky terapeutické užití MeSH
- lidé MeSH
- nemoc štěpu proti hostiteli terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- zprávy MeSH
Chronic myeloid leukemia (CML) is a malignant hematopoietic disorder distinguished by the presence of a BCR‑ABL1 fused oncogene with constitutive kinase activity. Targeted CML therapy by specific tyrosine kinase inhibitors (TKIs) leads to a marked improvement in the survival of the patients and their quality of life. However, the development of resistance to TKIs remains a critical issue for a subset of patients. The most common cause of resistance are numerous point mutations in the BCR‑ABL1 gene, followed by less common mutations and multiple mutation-independent mechanisms. Recently, exosomes, which are extracellular vesicles excreted from normal and tumor cells, have been associated with drug resistance and cancer progression. The aim of the present study was to characterize the exosomes released by imatinib‑resistant K562 (K562IR) cells. The K562IR‑derived exosomes were internalized by imatinib‑sensitive K562 cells, which thereby increased their survival in the presence of 2 µM imatinib. The exosomal cargo was subsequently analyzed to identify resistance‑associated markers using a deep label‑free quantification proteomic analysis. There were >3,000 exosomal proteins identified of which, 35 were found to be differentially expressed. From this, a total of 3, namely the membrane proteins, interferon‑induced transmembrane protein 3, CD146 and CD36, were markedly upregulated in the exosomes derived from the K562IR cells, and exhibited surface localization. The upregulation of these proteins was verified in the K562IR exosomes, and also in the K562IR cells. Using flow cytometric analysis, it was possible to further demonstrate the potential of CD146 as a cell surface marker associated with imatinib resistance in K562 cells. Taken together, these results suggested that exosomes and their respective candidate surface proteins could be potential diagnostic markers of TKI drug resistance in CML therapy.
- MeSH
- antigen CD146 metabolismus MeSH
- antigeny CD36 metabolismus MeSH
- apoptóza účinky léků MeSH
- bcr-abl fúzové proteiny antagonisté a inhibitory genetika MeSH
- buňky K562 MeSH
- chemorezistence MeSH
- chronická myeloidní leukemie farmakoterapie genetika patologie MeSH
- exozómy účinky léků metabolismus MeSH
- imatinib mesylát farmakologie terapeutické užití MeSH
- inhibitory proteinkinas farmakologie terapeutické užití MeSH
- lidé MeSH
- membránové proteiny metabolismus MeSH
- nádorové buněčné linie MeSH
- proteiny vázající RNA metabolismus MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Management a terapie pacientů s chronickou myeloidní leukemií (CML) doznaly za 20 let velkých změn. Zlatým standardem měření odpovědi na léčbu inhibitory tyrozinkináz (TKI) se stala metoda kvantitativní RT-PCR ke stanovení hladiny transkriptu BCR-ABL1. V zájmu sjednocení metodiky měření a její spolehlivosti došlo k mezinárodní harmonizaci interpretace výsledků vyšetření formou jejich vyjádření na mezinárodní škále a přidělování konverzního faktoru jednotlivým laboratořím na základě srovnání s referenčním pracovištěm. Časná molekulární odpověď na léčbu má významný vliv na průběh onemocnění a selektuje pacienty s dobrou prognózou. Část pacientů, kteří časné odpovědi nedosáhnou, má na další průběh i tak dobré vyhlídky. Pro jejich vyčlenění z rizikové skupiny je možno zohlednit kinetiku časného poklesu hladiny transkriptu. Koncept tzv. „halving time“ naznačuje vysokou míru úspěšnosti predikce citlivosti nemoci vůči nasazené terapii. V éře dlouhodobé terapie TKI je pořád častěji skloňovaným tématem možnost pokusu o remisi bez léčby (treatment-free remission – TFR). Tato strategie přináší možnost přerušit léčbu bez rekurence onemocnění, snížit její nežádoucí účinky a nezanedbatelnou ekonomickou zátěž systému. Identifikovat pacienty, u kterých lze tohoto cíle dlouhodobě dosáhnout, se však dodnes přesně nedaří. Stabilní TFR navíc udrží jen menšina pacientů. Volba léčebné strategie se tak může ubírat i snahou o maximální možnou redukci dávky TKI při trvající léčebné odpovědi. CML není vzorem jen pro cílenou léčbu a její úspěšnost, ale je ideální i pro matematické modelování onkologického onemocnění, mimo jiné i pro jednoduchost vyšetření nádorové nálože z periferní krve a její sledování v čase. Tímto lze do modelů zadávat jednoduše získaná a přesná data. Pomocí modelů jsme schopni simulovat podstatu vzniku CML z leukemické kmenové buňky, vliv TKI na tyto buňky, různé dávkovací režimy, pokus o TFR či odpověď imunitního systému na přítomnost nemoci. Následující text shrnuje přehled principů molekulárního měření léčebné odpovědi, vliv časné odpovědi a její kinetiky na prognózu pacientů a matematické modely CML v organizmu.
Management and therapy of patients with chronic myeloid leukaemia (CML) has changed significantly over the past twenty years. Quantitative RT-PCR detection of the BCR-ABL1 transcript level has become the gold standard for evaluating response to tyrosine kinase inhibitors (TKI) treatment. Demand for standardization of methodologies resulted in the international harmonisation of test result interpretation by expressing these on an international scale and assigning conversion factors to individual laboratories based on their comparison with reference sites. Early molecular response to treatment significantly influences the disease course and selects patients with good prognosis. Some of the patients who do not experience an early response still have good prospects in terms of disease course, as it is possible to take into consideration the kinetics of transcript level early decrease in order to exclude the high-risk group. The “halving time” concept indicates a high success rate for predicting disease sensitivity to the treatment given. In the era of long-term TKI therapy, attempts at a treatment-free remission (TFR) are being cited more frequently. This strategy involves the possibility of interrupting treatment without disease recurrence, decreasing adverse effects and the economic burden. Even today, identification of patients who are able to achieve this goal is hard and stable TFR is achieved only in a minority of patients. Treatment strategy may thus involve opting for a maximum possible reduction of TKI dose while still preserving treatment response. CML is not only a paradigm because of targeted treatment and its success rate but also because of its amenability for mathematical modelling of an oncological disease, given the simplicity of tumour load examination from peripheral blood and its real-time observation. This allows for easily acquired accurate data to be entered into the models. Using such models, we can simulate the origin of CML from the leukemic stem cell, TKI influence on these cells, various dosage regimens, attempts at TFR or the immune system response to presence of the disease. The following paper provides an overview of the principles of molecular measurement of treatment response, the consequences of early response and its kinetics on patient prognosis, and mathematical models of CML in the organism.
- Klíčová slova
- časná molekulární odpověď,
- MeSH
- chronická myeloidní leukemie * diagnóza patologie MeSH
- diagnostické techniky molekulární MeSH
- lidé MeSH
- spontánní remise MeSH
- teoretické modely MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
INTRODUCTION: Chronic myeloid leukemia (CML) is rare in the first two decades of life comprising only 3% of newly diagnosed pediatric and adolescent leukemias. We studied the epidemiologic and clinical features of patients with CML diagnosed at younger than 3 years of age and evaluated treatment and long-term outcome. METHOD: Data from the International Pediatric I-BFM/CML Registry were retrospectively analyzed using the European LeukemiaNet criteria of the year 2006. Characteristics and treatment outcome of patients <3 years old at diagnosis were evaluated from standardized forms. RESULTS: Twenty-two patients (n = 22/479; 4.6%, male/female:14/8) were enrolled with a median age of 22 months (range, 10-34 m). Major symptoms comprised asthenia (30%), fever (30%), abdominal pain (20%), extramedullary signs (14%), hemorrhage (5%), and weight loss (5%). The extramedullary signs were specified in eight children: blueberry muffin (n = 1), sudden swollen abdomen (n = 1), sustained vomiting (n = 1), and cervical and inguinal lymph nodes (n = 5). Two of five children with cervical and inguinal lymph nodes were categorized as accelerated phase. Overall, 19 of 22 (86%) children were diagnosed in chronic phase, while the remaining three patients were in advanced phase. Median follow-up was 78 months (range, 7-196 m). Twenty-one out of 22 patients initially received imatinib, while one child received IFN + ARA-C. Imatinib was changed to second-line tyrosine kinase inhibitors (TKIs) in 29% of cases. During follow-up, 41% patients underwent stem cell transplantation (SCT). While on TKI, major molecular response (MMR) was achieved in 48% of children. Among the remaining patients, 21% are alive on TKI without MMR and 22% achieved complete molecular response following SCT. Twenty-one of 22 (95%) children are alive, while one patient died of posttransplant complications. CONCLUSION: This report demonstrates for the first time the efficacy and long-term effects of upfront imatinib in the so far largest cohort of children with CML diagnosed at very young age.
- MeSH
- chronická myeloidní leukemie patologie terapie MeSH
- kojenec MeSH
- kombinovaná terapie MeSH
- lidé MeSH
- míra přežití MeSH
- následné studie MeSH
- předškolní dítě MeSH
- prognóza MeSH
- protokoly antitumorózní kombinované chemoterapie terapeutické užití MeSH
- registrace statistika a číselné údaje MeSH
- transplantace hematopoetických kmenových buněk mortalita MeSH
- Check Tag
- kojenec MeSH
- lidé MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The present nuclear and cell body diameter measurements demonstrated size differences of the approximate cell space estimate occupied by the cell nucleus during the cell differentiation in lymphocytic, granulocytic and erythroid cell lineages. These lineages were used as convenient models because all differentiation steps were easily identified and accessible in diagnostic peripheral blood or bone marrow smears of blood donors (BDs), patients suffering from chronic lymphocytic leukemia (CLL), patients with chronic myeloid leukemia (CML) and refractory anemia (RA) of the myelodysplastic syndrome (MDS). The cell space occupied by the nucleus was constant and did not change during the cell differentiation in the lymphocytic cell lineages of BDs and CLL patients despite the decreased cell size. In contrary, the cell space occupied by the nucleus markedly decreased in differentiating cells of granulocytic and erythroid lineages of patients suffering from CML. In the erythroid cell lineage in patients with RA of MDS the small reduction of the cell space occupied by the nucleus during the differentiation was not significant. The measurements also indicated that in progenitor cells of all studied cell lineages nuclei occupied more than 70 % of the cell space. Thus, the nucleus-cytoplasmic morphological and functional equilibrium appeared to be characteristic for each differentiation step and each specific cell lineage.
- MeSH
- buněčná diferenciace * MeSH
- buněčné jádro * MeSH
- chronická lymfatická leukemie patologie MeSH
- chronická myeloidní leukemie patologie MeSH
- erytroidní buňky cytologie MeSH
- granulocyty cytologie MeSH
- lidé MeSH
- lymfocyty cytologie MeSH
- refrakterní anemie patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
