scholarly journals Global identification of circular RNAs in imatinib (IM) resistance of chronic myeloid leukemia (CML) by modulating signaling pathways of circ_0080145/miR-203/ABL1 and circ 0051886/miR-637/ABL1

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Yao-hua Lu ◽  
Zhong-yi Huang

AbstractImatinib (IM), targeting of BCR-ABL1 tyrosine kinase, is currently one of the first-line choices in the treatment of chronic myeloid leukemia (CML). This study aims to explore the molecular mechanisms underlying IM resistance in CML treatment. 108 CML patients were recruited and grouped according to their sensitivity to IM as the responder group (N = 66) and the non-responder group (N = 42). Real-time quantitative PCR (RT-qPCR) was performed to evaluate the expression of candidate circular RNAs (circRNAs), microRNA (miRNAs) and messenger RNA (mRNAs). No significant difference was noted regarding demographic and clinicopathological characteristics between the responder group and the non-responder group. The expression of circ_0080145, circ_0051886 and ABL1 mRNA was significantly increased, while the expression of miR-203 and miR-637 was decreased in the non-responder group as compared with the responders. By using in-silicon analysis, it was predicted that circ_0080145 and circ_0051886 targeted miR-203 and miR-637 respectively, and ABL1 was found to be shared direct target gene of miR-203 and miR-637. Ectopic over-expression of circ_0080145 and circ_0051886 respectively reduced the expression of miR-203 and miR-637. The expression of ABL1 mRNA/protein was most upregulated in culture cells co-transfected with circ_0080145 and circ_0051886 as compared with those cells individually transfected. This study established the signaling pathways of circ_0080145/miR-203/ABL1 and circ 0051886/miR-637/ABL1. The deregulation of circ_0080145 and circ_0051886 is, at least partially, responsible for the development of IM chemoresistance in CML by regulating expression of ABL1 via modulating expression of miR-203 and miR-637.

Author(s):  
Vivien Schäfer ◽  
Helen E. White ◽  
Gareth Gerrard ◽  
Susanne Möbius ◽  
Susanne Saussele ◽  
...  

Abstract Purpose Approximately 1–2% of chronic myeloid leukemia (CML) patients harbor atypical BCR-ABL1 transcripts that cannot be monitored by real-time quantitative PCR (RT-qPCR) using standard methodologies. Within the European Treatment and Outcome Study (EUTOS) for CML we established and validated robust RT-qPCR methods for these patients. Methods BCR-ABL1 transcripts were amplified and sequenced to characterize the underlying fusion. Residual disease monitoring was carried out by RT-qPCR with specific primers and probes using serial dilutions of appropriate BCR-ABL1 and GUSB plasmid DNA calibrators. Results were expressed as log reduction of the BCR-ABL1/GUSB ratio relative to the patient-specific baseline value and evaluated as an individual molecular response (IMR). Results In total, 330 blood samples (2–34 per patient, median 8) from 33 CML patients (19 male, median age 62 years) were analyzed. Patients expressed seven different atypical BCR-ABL1 transcripts (e1a2, n = 6; e6a2, n = 1; e8a2, n = 2; e13a3, n = 4; e14a3, n = 6; e13a3/e14a3, n = 2; e19a2, n = 12). Most patients (61%) responded well to TKI therapy and achieved an IMR of at least one log reduction 3 months after diagnosis. Four patients relapsed with a significant increase of BCR-ABL1/GUSB ratios. Conclusions Characterization of atypical BCR-ABL1 transcripts is essential for adequate patient monitoring and to avoid false-negative results. The results cannot be expressed on the International Scale (IS) and thus the common molecular milestones and guidelines for treatment are difficult to apply. We, therefore, suggest reporting IMR levels in these cases as a time-dependent log reduction of BCR-ABL1 transcript levels compared to baseline prior to therapy.


2006 ◽  
Vol 63 (4) ◽  
pp. 364-369 ◽  
Author(s):  
Milica Strnad ◽  
Goran Brajuskovic ◽  
Natasa Strelic ◽  
Biljana Zivanovic-Todoric ◽  
Ljiljana Tukic ◽  
...  

Background/Aim. Chronic myeloid leukemia (CML) represents a malignant myeloproliferative disease developed out of pluripotent hematopoietic stem cell that contains the fusion bcr-abl gene. Disorders that occur in the process of apoptosis represent one of the possible molecular mechanisms that bring about the disease progress. The aim of our study was to carry out the analysis of the presence of the amplification of the cmyc oncogene, as well as the analysis of the changes in the expression of Bcl-2 in the patients with CML. Methods. Our study included 25 patients with CML (18 in chronic phase, 7 in blast transformation). Using an immunohistochemical alkaline phosphatase-anti-alkaline phosphatase (APAAP) method, we analyzed the expression of cell death protein in the mononuclear bone marrow cells of 25 CML patients. By a differential PCR (polymerase chain reaction) method, we followed the presence of amplified c-myc gene in mononuclear peripheral blood cells. Results. The level of the expression of Bcl-2 protein was considerably higher in the bone marrow samples of the patients undergoing blast transformation of the disease. The amplification of c-myc gene was detected in 30% of the patients in blast transformation of the disease. Conclusion. The expression of Bcl-2 protein and the amplification of c-myc gene are in correlation with the disease progression.


2021 ◽  
Author(s):  
K M Taufiqur Rahman ◽  
Md. Fahmid Islam ◽  
Sanjib Saha ◽  
Md. Morsaline Billah

Background: The network biology of disease-gene association provides a holistic framework to decipher the intrinsic complexity of disease signaling pathways into cellular communication level. Different types of studies including large-scale genome-wide association, multifactor dimensional reduction analysis, whole genome, or exome-based sequencing strategies of diseases are striving to connect genes to diseases. Indeed, these approaches have had some accomplishments, but the cellular communication level needs a more streamlining outcome to understand the mechanistic impact of context. The higher-order combination of disease-gene interaction has a great potential to decipher the intricateness of diseases. The molecular interaction pattern of diseases at the genomic and proteomic level offers a revolutionized platform not only to understand the complexity of particular disease modules and pathways but also leading towards design novel therapeutics. Results: The enrichment and topology analysis was performed by JEPETTO a plugin of Cytoscape software. We identified the chronic myeloid leukemia (CML) disease signaling pathways that appeared first in the ranking order based on XD-score among the bone, breast, and colon genes set and second at kidney and liver. This result validates the highest proximity between CML and five cancerous tissue gene set clusters. The topology analysis also supports the results while (p<0.0001) is considered to be extremely significant between CML and fives cancerous tissues genes set. Enrichment analysis identified that abl-gene acts as an overlapping node which is the major gene for inducing various mutations in CML. Amazingly, we identified 56 common path expansion/added genes among these five cancerous tissues which can be considered the direct cofactors of CML disease. By relative node degree, resolution, possible ligand, stoichiometry, Q-mean, and Z-score analysis we found 11 hubs proteins like SMAD3, GRB2, TP53, SMAD4, RB1, HDAC1, RAF1, ABL1, SHC1, TGFBR1, RELA which can be regarded for further drug target identification. Conclusions: Our proposed network analysis reflects on the gene set interaction pattern of disease signaling pathways of humans. The integrated multidrug computational and experimental approaches boost up to improve the novel drug target approach. Besides, such a trove can yield unprecedented insights to lead to an enhanced understanding of potential application both in drug target optimization and for drug dislodging.


Hematology ◽  
2003 ◽  
Vol 2003 (1) ◽  
pp. 132-152 ◽  
Author(s):  
Junia V. Melo ◽  
Timothy P. Hughes ◽  
Jane F. Apperley

Abstract Chronic myeloid leukemia (CML) was the first human malignancy to be associated with a specific genetic lesion, the Philadelphia chromosome, harboring the BCR-ABL oncogene. Since then, it has become a paradigm for the discovery of molecular mechanisms and targeted therapeutic approaches in the field of hematologic neoplasias. The past 5 years or so have been particularly fruitful in the dissection of the signal transduction pathways abnormally activated in CML and in the translation of this knowledge to clinical practice. In this report, we discuss the biological basis for such translation and highlight the current and potential tools for the effective treatment of CML patients. The first part presents a review of the basic concepts on the biology of CML and their application to the design of targeted therapy. The mechanisms of action of the molecular-specific drugs currently used in clinical trials are discussed, with emphasis on the description of the most promising new compounds that are enhancing the potential for effective alternative or combination chemotherapy in CML. In the following section, we explain how molecular monitoring of response to imatinib mesylate in patients with CML can be used as a guide to clinical management. In particular, we discuss the relative value of regular quantitative RT/PCR and cytogenetic analyses, how responding patients should be monitored and managed, and how to investigate patients who are refractory or become resistant to imatinib treatment. In the last part of this report, a discussion on the possibility of managing CML with patient-specific strategies is presented. We review the current treatment options, highlight the factors impacting on decision making, discuss the range of possibilities for future therapeutic strategies and propose a systematic approach for individualizing treatment for patients in different disease categories.


Leukemia ◽  
2020 ◽  
Author(s):  
Shady Adnan-Awad ◽  
Daehong Kim ◽  
Helena Hohtari ◽  
Komal Kumar Javarappa ◽  
Tania Brandstoetter ◽  
...  

Abstract The oncogenic protein Bcr-Abl has two major isoforms, p190Bcr-Abl and p210Bcr-Abl. While p210Bcr-Abl is the hallmark of chronic myeloid leukemia (CML), p190Bcr-Abl occurs in the majority of Philadelphia-positive acute lymphoblastic leukemia (Ph + ALL) patients. In CML, p190Bcr-Abl occurs in a minority of patients associating with distinct hematological features and inferior outcomes, yet the pathogenic role of p190Bcr-Abl and potential targeting therapies are largely uncharacterized. We employed next generation sequencing, phospho-proteomic profiling, and drug sensitivity testing to characterize p190Bcr-Abl in CML and hematopoietic progenitor cell line models (Ba/f3 and HPC-LSK). p190Bcr-Abl CML patients demonstrated poor response to imatinib and frequent mutations in epigenetic modifiers genes. In contrast with p210Bcr-Abl, p190Bcr-Abl exhibited specific transcriptional upregulation of interferon, interleukin-1 receptor, and P53 signaling pathways, associated with hyperphosphorylation of relevant signaling molecules including JAK1/STAT1 and PAK1 in addition to Src hyperphosphorylation. Comparable to p190Bcr-Abl CML patients, p190Bcr-Abl cell lines demonstrated similar transcriptional and phospho-signaling signatures. With the drug sensitivity screening we identified targeted drugs with specific activity in p190Bcr-Abl cell lines including IAP-, PAK1-, and Src inhibitors and glucocorticoids. Our results provide novel insights into the mechanisms underlying the distinct features of p190Bcr-Abl CML and promising therapeutic targets for this high-risk patient group.


Proceedings ◽  
2018 ◽  
Vol 2 (25) ◽  
pp. 1524
Author(s):  
Ergul Mutlu Altundağ ◽  
Ayşe Mine Yılmaz ◽  
Belgin Sert ◽  
Tuğba Erkmen ◽  
Semra Koçtürk ◽  
...  

Flavonoids have chemo-preventive and chemotherapeutic properties against different human cancers including chronic myeloid leukemia. Quercetin and curcumin are two polyphenols with potential anti-carcinogenic and pro-apoptotic properties. We have previously demonstrated the synergistic protective effect of quercetin and curcumin on chronic myeloid leukemia cells (K562) cells. Anti-proliferative and apoptotic effects of these polyphenols were examined by apoptosis and cell viability assays. Oxidative status of the cells was analyzed by determining the level of reactive oxygen species, mitochondrial permeability and intracellular glutathione. Obtained data showed that quercetin and curcumin had beneficial and synergistic effects on K562 cells. On the basis of the above-mentioned data, herein we aimed to clarify signaling pathways involved in synergistic combination of quercetin and curcumin on K562 cells. Normal peripheral blood mononuclear cell line was used as controls. The mRNA and protein expressions of the signaling pathways were detected by Human Signal Transduction Pathway Finder-RT2 PCR Array system and Western blotting, respectively. The results of PCR array were evaluated by DAVID v6.8 and database for KEGG pathways. Our data revealed that synergistic combination of curcumin quercetin was effective on genes that were particularly related to P53, NF and TGF. We believe that our findings will lead to new research in this area and will contribute to the chronic myeloid leukemia treatment protocols.


Blood ◽  
1996 ◽  
Vol 87 (9) ◽  
pp. 3822-3827 ◽  
Author(s):  
N Testoni ◽  
G Martinelli ◽  
P Farabegoli ◽  
A Zaccaria ◽  
M Amabile ◽  
...  

Methods of detecting minimal residual disease (MRD) in chronic myeloid leukemia (CML) include chromosome analysis, Southern blotting, polymerase chain reaction (PCR) and fluorescent in situ hybridization (FISH) techniques. We report a novel method to detect intracellular messenger RNA (mRNA) by combining the techniques of reverse transcription (RT) and PCR performed directly inside the cells, without extraction of the nucleic acid. We applied this method, which we call “in-cell RT-PCR”, to detect hybrid BCR/ABL transcript within single cells. After cellular permeabilization and fixation of single cells in suspension, the neoplastic mRNA was reverse transcribed into cDNA, and the cDNA was amplified by PCR with fluorescent primers, specific for bcr/abl. Flow cytometry was used to detect cells positive for the amplified DNA within the cell cytoplasm. After transferring the amplified cells onto slides by cytospin, the positive cells for BCR/ABL cDNA were observed by fluorescent microscopy. The technique was capable of detecting low abundancy signals and distinguishing different levels of gene expression. The amplification products were found in the cells and supernatants. The distribution was critically affected by the protease digestion condition. The specificity of amplification was confirmed by a nested RT-PCR of BCR/ABL performed on extracted mRNA from the same sample, and by reamplification of supernatants. We have used the technique to study 10 Ph+ CML patients and three normal subjects as controls. Four patients were 100% Ph+ at diagnosis time and RT-PCR+ at cytogenetic and molecular analysis, respectively. In-cell RT- PCR showed that the residual non-neoplastic cells could be observed in all cases. In two patients undergoing interferon-alpha (IFN-alpha) therapy and in four bone-marrow transplanted patients, the in-cell RT- PCR was used to compare the level of Ph+ positivity detected by cytogenetic analysis with the number of cells expressing BCR/ABL transcript. In this manner, we could estimate the MRD. Our preliminary application of the technique suggests that it is capable of accurately identifying cells transcribing bcr/abl, and that it may have significant clinical applications in the detection of MRD.


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