The Embryonic Program Activated during Blast Crisis of Chronic Myelogenous Leukemia (CML) Implicates a TCF7L2 and MYC Cooperative Chromatin Binding and Represents a Druggable Target

Chronic myeloid leukemia (CML) is characterized by an inherent genetic instability, which contributes to the progression of the disease towards accelerated and blast crisis (BC). The occurrence of the latter has been hampered by the use of tyrosine kinase inhibitors (TKI), which changed this natural progression, but BC still occurs in patients resistant to TKI. Several cytogenetic (major and minor routes) and genomic (TP53 mutation, p16/INK4A deletions, DNA repair abnormalities such as BRCA1, DNA-PKcs, hnRNP metabolism) events have been reported in the progression towards BC. Previous data have also suggested the involvement of embryonic stem cell program activated in BC cells such as Lin28A. In this work, we have taken advantage of the previously reported gene profiling of BC in a large cohort of patients (Radich et al. 2006) and found a correlation between blast numbers and the involvement of the Transcription Factor 7 like 2 (TCF7L2) in BC. TFC7L2 is a member of the TCF family of proteins that are known to activate WNT target genes such as Cyclin D1. TCF7L2 has been shown to be overexpressed in acute myeloid leukemia (AML) and represents a druggable target (Saenz et al Leukemia 2019). The involvement of TCF7L2 in CML-BC and its interaction with the epigenetic regulators has not been studied so far. The gene correlation study that we have performed using the blast numbers and the expression of TCF7L2 in CD34+ CML cells was found to be highly significant (Pearson test, r = 0.56, p-value=5.2e-4) (Fig.1A). TCF7L2 promoter was classed as active in K562 with ChromHMM Functional genomic analysis. K562 epigenetics peaks of TCF7L2 CHIP-seq were found principally mapped in proximal promoters (39% of the peaks, -3000pb upstream Transcription Starting Sites (TSS), Fig. 1B) and 183 unique peaks matched with promoter of 144 unique genes found to be correlated to the blast number in blood of the CML patients during BC (Fig 1C). This TCF7L2-dependent BC program was characterized to be active because promoters were also found positive for H3K27Ac and negative for H3K27Me3 histone marks, and functionally enriched with binding sites for MYC/MAX interactions (p=1.15e-6). The analysis of CHIP-sequencing of MYC revealed a significant overlapping of TCF7L2 epigenetic program with MYC (fold enrichment: 20.81, p < 2.2e-16). Surprisingly, the TCF7L2 program was found independent of RUNX1 and GATA2 transcriptional program. To determine these potential interactions, we have designed experiments in K562 cell line using the b-catenin activator Lithium Chloride (LiCL2) and the Myc/Max dimerization inhibitor 10058-F4. K562 cells were cultured in the presence of LiCL2 (10mM & 24hours) and the compound 10058-F4 (64µM & 48hours) and the expression of three epigenetic targets was analyzed by Q-RT-PCR in the presence of DMSO controls. The three targets chosen were protein arginine N-methyltransferase (PRMT1), the ATPase/Helicase RUVBL1 and the WD-repeat containing protein WDR77. As expected, after culture with LiCL2, the expression of PRMT1 was increased x 6.3 fold (p=8.49e-13) , that of RUVBL1 by x 1.66 Fold (p=1.67e-6) and that of WDR77 by x 2 fold (p=4.97e) (Fig.1D). On the contrary, the culture of K562 cells in the presence of MYC/MAX inhibitor 10058-F4, decreased the expression of 3 targets as compared to DMSO controls (x 1.6 fold for PRMT1, p=6.52e-5; x2 fold reduction for RUVBL1, p-value=2.71e-5; and x 1.4 fold for WDR77, p =0.0000643). These results show for the first time a cooperative role of TCF7L2 and MYC during blast crisis of CML and provide mechanistic insights into the interactions for the role of MYC in CML blast crisis. In addition they strengthen previous data showing a possible embryonic footprint in the blast development over the hematopoietic differentiation program during progression of the disease and provide a rationale for the pharmacological targeting of BC by the use of MYC/MAX inhibitors such as 10058-F4. Experiments are underway to evaluate the role of these factors and the MYC/MAX inhibitors in primary CML samples. Reference : Radich JP, Dai H, Mao M, Oehler V, Schelter J, Druker B, Sawyers C, Shah N, Stock W, Willman CL, Friend S, Lindsey PS.(2006) :Gene Expression Changes Associated with Progression and Response in Chronic Myeloid Leukemia. Proceedings of the National Academy of Sciences of the United States of America 103 (8): 2794-99. Disclosures Turhan: Incyte: Consultancy, Honoraria; novartis: Honoraria, Research Funding.

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ETS1 Expression Is Upregulated in Chronic Myeloid Leukemia (CML) and the ETS1 Transcriptional Program Correlates with Disease Progression Towards Blast Crisis

Blood ◽

10.1182/blood.v128.22.442.442 ◽

2016 ◽

Vol 128 (22) ◽

pp. 442-442

Author(s):

Christophe Desterke ◽

Maud Voldoire ◽

Nathalie Sorel ◽

Marie Laure Bonnet ◽

Sarah Pagliaro ◽

...

Keyword(s):

Stem Cell ◽

Chronic Myeloid Leukemia ◽

Myeloid Leukemia ◽

Blast Crisis ◽

Leukemic Cells ◽

P Value ◽

Healthy Controls ◽

Transcriptional Program ◽

Chip Sequencing ◽

Cd34 Cells

Abstract Chronic myeloid leukemia is a clonal myeloproliferative neoplasm characterized by the occurrence of the Ph1 chromosome in a primitive hematopoietic stem cell with a major amplification of myeloid compartment. Despite the major progress obtained by the use of tyrosine kinase inhibitors (TKI), resistances to these drugs occur with progression towards blast crisis (BC) during which there is an increase of BCR-ABL expression. To evaluate the potential targets of BCR-ABL in this context, a gene profiling analysis of the UT7-11 cell line overexpressing BCR-ABL fusion protein was performed using a whole transcriptome microarray. One of the highly upregulated genes was ETS1 with a fold change of +35.86. ETS1 proto-oncogene, the founder member of the ETS-domain family of transcription factors such as TEL and FLI1, is the human homolog of the avian erythroblastosis virus E26. They play a crucial role in stem cell biology, tumorigenesis and ETS1 has been shown to be involved in the regulation of granulocytic differentiation. Its role in CML pathophysiology has not been studied so far. We first showed by Western blots that ETS1 protein was highly increased in UT7-11 cells as compared to parental UT7 cells. Using a DOX-Inducible BCR-ABL system, we have shown that ETS1 expression was downregulated upon inhibition of BCR-ABL expression. ETS1 expression was a tyrosine kinase dependent event as its expression was reduced in the presence of TKI. To determine if ETS1 expression is upregulated in primary leukemic cells, we have analyzed leukemic cells of CML patients at diagnosis (n= 40) as compared to healthy controls (n= 30) showing an increase of ETS1 mRNA expression in primary CML cells in a highly significant manner (p < 0.0007). We then analyzed ETS1 targets using chip-sequencing in K562 cells, performed on HG19 human genome allowing to predict 3209 proximal promoters (-3000 upstream pb, + 50pb around Transcription Starting Sites) which represents a promoter enrichment of +33.68 (p-value=4.9E-324) as compared to the distribution of peaks in the whole genome. Chromosomes 19, 16, 17, 11, 12 and 1 were found over-represented with ETS1 bound events in Chip-sequencing. Integration of BCR-ABL transcriptome with ETS1 promoters identified by Chip-Sequencing led to the identification of 130 ETS1-targets activated by BCR-ABL, allowing reclassification of BCR-ABL transfected samples with transcriptome data by unsupervised classification. ETS1 transcriptional program regulated by BCR-ABL analysis performed on CD34+ from CML patients during progression of the disease (GSE47927) allowed discrimination of the different states of the progression (from the chronic phase to accelerated phase and BC p-value=1.63E-33). This analysis was also found significant by Gene Set Enrichment Analysis ETS1_BC specific geneset (NES=+1.52, p-value<0.0001). Among this ETS1 program specific of BC, we identified 2 targets that are discriminant for CD34+ cells of CML patients without cytogenetic response under Imatinib therapy. These two genes were Dynamin 3 (DNM3) and LIMS1/ PINCH1. Dynamin 3 is a member of the motor proteins implicated in cell motility and cytokinesis and it is implicated in megakaryocyte development whereas LIMS1 / PINCH1 is essentially involved in cell migration and adhesion. In order to validate ETS1 and its target expressions in a novel cohort of CML patients, we have analyzed the expression of DNM3 and PINCH1 in whole blood samples in CML patients ( n= 60 ) as compared to healthy controls (n= 32). We have found that, similar to ETS1, DNM3 and LIMS1 / PINCH1 mRNA were highly upregulated in primary CML and this increase was highly significant. In this new cohort of patients, DNM3 transcript levels were inversely correlated to WBC count (r=-0.32, p-value=0.011) and especially in male gender (r=-0.43, p-value=0.012). The expression of LIMS1 was inversely correlated with the age at diagnosis and the major molecular response at 12 months. Thus, our results show for the first time the major upregulation of ETS1 transcriptional program in CML. ETS1 transcriptional program has been found to correlate with the gene expression pattern involved in the progression of the disease in the transcriptomic analysis of CML CD34+ cells. The novel druggable targets that we identified in the BCR-ABL-activated transcriptional program is currently under investigation to determine their use in patients with resistance to targeted therapies. Disclosures No relevant conflicts of interest to declare.

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Role of eIF3a in 4-amino-2-trifluoromethyl-phenyl retinate-induced cell differentiation in human chronic myeloid leukemia K562 cells

Gene ◽

10.1016/j.gene.2018.10.035 ◽

2019 ◽

Vol 683 ◽

pp. 195-209 ◽

Cited By ~ 4

Author(s):

Ge Li ◽

Ke Wang ◽

Yue Li ◽

Jinging Ruan ◽

Cong Wang ◽

...

Keyword(s):

Cell Differentiation ◽

Chronic Myeloid Leukemia ◽

Myeloid Leukemia ◽

K562 Cells

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A Novel Methoxybenzyl 5-Nitroacridone Derivative Effectively Triggers G1 Cell Cycle Arrest in Chronic Myelogenous Leukemia K562 Cells by Inhibiting CDK4/6-Mediated Phosphorylation of Rb

International Journal of Molecular Sciences ◽

10.3390/ijms21145077 ◽

2020 ◽

Vol 21 (14) ◽

pp. 5077

Author(s):

Bin Zhang ◽

Ting Zhang ◽

Tian-Yi Zhang ◽

Ning Wang ◽

Shan He ◽

...

Keyword(s):

Cell Cycle ◽

Chronic Myeloid Leukemia ◽

Cell Cycle Arrest ◽

Chronic Myelogenous Leukemia ◽

Myeloid Leukemia ◽

K562 Cells ◽

Myelogenous Leukemia ◽

G1 Phase ◽

Cycle Arrest ◽

G1 Cell Cycle Arrest

Chronic myeloid leukemia (CML) is a malignant tumor caused by the abnormal proliferation of hematopoietic stem cells. Among a new series of acridone derivatives previously synthesized, it was found that the methoxybenzyl 5-nitroacridone derivative 8q has nanomolar cytotoxicity in vitro against human chronic myelogenous leukemia K562 cells. In order to further explore the possible anti-leukemia mechanism of action of 8q on K562 cells, a metabolomics and molecular biology study was introduced. It was thus found that most of the metabolic pathways of the G1 phase of K562 cells were affected after 8q treatment. In addition, a concentration-dependent accumulation of cells in the G1 phase was observed by cell cycle analysis. Western blot analysis showed that 8q significantly down-regulated the phosphorylation level of retinoblastoma-associated protein (Rb) in a concentration-dependent manner, upon 48 h treatment. In addition, 8q induced K562 cells apoptosis, through both mitochondria-mediated and exogenous apoptotic pathways. Taken together, these results indicate that 8q effectively triggers G1 cell cycle arrest and induces cell apoptosis in K562 cells, by inhibiting the CDK4/6-mediated phosphorylation of Rb. Furthermore, the possible binding interactions between 8q and CDK4/6 protein were clarified by homology modeling and molecular docking. In order to verify the inhibitory activity of 8q against other chronic myeloid leukemia cells, KCL-22 cells and K562 adriamycin-resistant cells (K562/ADR) were selected for the MTT assay. It is worth noting that 8q showed significant anti-proliferative activity against these cell lines after 48 h/72 h treatment. Therefore, this study provides new mechanistic information and guidance for the development of new acridones for application in the treatment of CML.

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Transfected leukocyte integrin CD11b/CD18 (Mac-1) mediates phorbol ester-activated, homotypic cell:cell adherence in the K562 cell line

Blood ◽

10.1182/blood.v82.8.2537.2537 ◽

1993 ◽

Vol 82 (8) ◽

pp. 2537-2545 ◽

Cited By ~ 10

Author(s):

DD Hickstein ◽

E Grunvald ◽

G Shumaker ◽

DM Baker ◽

AL Back ◽

...

Keyword(s):

Cell Line ◽

Cell Activation ◽

Blast Crisis ◽

K562 Cells ◽

Myelogenous Leukemia ◽

Cell Clones ◽

A Cell ◽

Neutrophil Adherence ◽

The Individual

Abstract The CD11b/CD18 leukocyte integrin molecule mediates diverse neutrophil adherence-related functions, including cell:cell and cell:extracellular matrix attachments. To study the individual role of this leukocyte integrin in cell adherence in hematopoietic cells, we expressed the CD11b/CD18 complex on the surface of K562 cells, a cell line derived from an individual with chronic myelogenous leukemia in blast crisis. We used an amphotrophic retroviral vector designated LCD18SN, harboring the complete coding sequence for the CD18 subunit, to transfer the CD18 cDNA into K562 cells and select stable cell lines. The CD11b subunit in the expression plasmid pREP4 was transfected into these K562/CD18 cells by electroporation and stable cell clones were selected. These K562 cells possessed RNA and intracellular protein for each subunit, and they expressed the CD11b/CD18 heterodimer on the cell surface. When CD11b/CD18 expressing K562 cells were stimulated with phorbol myristate acetate (50 ng/mL) for 24 to 48 hours, these K562 cells formed dense cell:cell aggregates. This homotypic aggregation required both activation of the CD11b/CD18 complex and the induction of the counter- receptor for CD11b/CD18 on the conjugate cell. This cell line will (1) enable the structure-function relationships between cell activation and homotypic adherence to be assessed, (2) provide the opportunity to identify accessory molecules required for activation of the CD11b/CD18 complex, and (3) facilitate the identification of novel ligands for the CD11b/CD18 complex.

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Molecular biology of bcr-abl1–positive chronic myeloid leukemia

Blood ◽

10.1182/blood-2008-03-144790 ◽

2009 ◽

Vol 113 (8) ◽

pp. 1619-1630 ◽

Cited By ~ 370

Author(s):

Alfonso Quintás-Cardama ◽

Jorge Cortes

Keyword(s):

Chronic Myeloid Leukemia ◽

Myeloid Leukemia ◽

Kinase Inhibitors ◽

Current Knowledge ◽

Blast Crisis ◽

Chronic Phase ◽

Oncogenic Signaling ◽

Stem Cell Quiescence ◽

Oncogenic Signaling Pathways

Abstract Chronic myeloid leukemia (CML) has been regarded as the paradigmatic example of a malignancy defined by a unique molecular event, the BCR-ABL1 oncogene. Decades of research zeroing in on the role of BCR-ABL1 kinase in the pathogenesis of CML have culminated in the development of highly efficacious therapeutics that, like imatinib mesylate, target the oncogenic kinase activity of BCR-ABL1. In recent years, most research efforts in CML have been devoted to developing novel tyrosine kinase inhibitors (TKIs) as well as to elucidating the mechanisms of resistance to imatinib and other TKIs. Nonetheless, primordial aspects of the pathogenesis of CML, such as the mechanisms responsible for the transition from chronic phase to blast crisis, the causes of genomic instability and faulty DNA repair, the phenomenon of stem cell quiescence, the role of tumor suppressors in TKI resistance and CML progression, or the cross-talk between BCR-ABL1 and other oncogenic signaling pathways, still remain poorly understood. Herein, we synthesize the most relevant and current knowledge on such areas of the pathogenesis of CML.

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Identification of Rab5 as a Gene Involved in Chronic Myeloid Leukemia (CML) Progression.

Blood ◽

10.1182/blood.v114.22.3470.3470 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3470-3470

Author(s):

Daniela Cilloni ◽

Monica Pradotto ◽

Francesca Messa ◽

Francesca Arruga ◽

Enrico Bracco ◽

...

Keyword(s):

Chronic Myeloid Leukemia ◽

Western Blot ◽

Myeloid Leukemia ◽

Conflicts Of Interest ◽

Blast Crisis ◽

Small Gtpases ◽

Loss Of Function ◽

Imatinib Resistance ◽

Protein Levels

Abstract Abstract 3470 Poster Board III-358 The role of Bcr-Abl in the pathogenesis of Chronic Myeloid Leukemia (CML) is well established, however, the mechanisms leading to CML progression remain poorly understood. By using our model of transgenic Drosophila Melanogaster (Dm) for human Bcr-Abl driven CML we have identified Rab5 as a gene involved in the regulation of CML progression. The Rab5 is a member of gene family small GTPases which are involved in the regulation of vesicular transport. Lately several important reports have linked some members of the Rab family to invesivness and migration of cancer cells. Rab5 is associate with alpha-integrin subunits and modulates their endosomal traffic and subcellular localization. We have observed that a loss of function of Rab5 gene have induced a worsening of the CML phenotype generated by hBcr-Abl expression. In contrast, Rab gain of function rescued Bcr-Abl phenotype. The aim of the study was to evaluate the expression of Rab5 in CML cells to better understand if a potential correlation with progression, which has been observed in the model, could be confirmed in patients. Methods Rab5 gene expression was measured by Real Time PCR in 90 samples from 80 CML patients (32 PB and 58 BM). Among those, 53 are collected at diagnosis (19 of 53 patients have been enrolled in TOPS study). In addition, 9 samples from in CP patients have been collected at the time of imatinib resistance, 7 in accelerated phase and 11 in BC. In 14 patients, genes expression was analyzed during remission as, well. In parallel, 21 healthy donors (10 PB and 11 BM) have been evaluated. Rab5 protein expression was investigated by Western Blot and Immunofluorescence. We have also utilized K562 transfected with Rab5 plasmid, which we have generated to gain insight about the effects of Rab5 on cell proliferation and apoptosis. Results Rab5 transfection and overexpression in K562 significantly reduced proliferation and affected apoptosis. We found that in CML patients Rab5 expression levels were significantly decreased in either BM or PB (p<0.001 and p<0.0001) as compared to healthy subjects. Furthermore, in blast crisis samples we have found Rab5 transcripts levels to be further decreased. In contrast, at the time of remission, the transcript levels were comparable to normal values. Our preliminary analysis of samples from TOPS trial have shown a trend that Rab5 levels are lower among those patients achieving MMR by 12 months, when compared to the group of patients non achieving MMR on 400 mg, but that difference was not statistically significant (p=0.2). Among those randomized to receive imatinib 800 mg the difference was statistically significant with a median value among those achieving MMR of 1.27 vs 2.14 in the group without MMR (p=0.04). The protein levels have been analyzed by Western Blot and immunofluorescence and allow us to show detectable levels of Rab5 in samples collected at remission, but undetectable levels in course of active CML disease. Although preliminary, our results show a significant decrease of Rab5 expression in blast crisis samples, when compared to CP CML and healthy volunteers, which suggest a role of Rab5 in slowing down or suppressing a progression. Surprisingly, among CP CML patients the responders to TKI therapy have been detected to express a lower level of Rab5 than non responders. We are conducting further studies to better explain these data, which we find intriguing and suggesting that molecular factors involved in the regulation of CML progression could be uncoupled from the mechanisms regulating response to TKI therapy. Supported by Novartis Oncology, Clinical Development, TOPS Clinical Correlative Studies Network Disclosures No relevant conflicts of interest to declare.

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PHD Domain Deletion Mutations of ASXL1 Promote Myeloid Leukemia Transformation Through Epigenetic Dysregulation and Inhibit Megakaryocytic Differentiation Through the Inactivation of FOSB in K562 Cells.

Blood ◽

10.1182/blood.v120.21.2393.2393 ◽

2012 ◽

Vol 120 (21) ◽

pp. 2393-2393 ◽

Cited By ~ 1

Author(s):

Rabindranath Bera ◽

Der-Cherng Liang ◽

Ming-Chun Chiu ◽

Ying-Jung Huang ◽

Sung-Tzu Liang ◽

...

Keyword(s):

Myeloid Leukemia ◽

Molecular Mechanisms ◽

Blast Crisis ◽

K562 Cells ◽

Specific Cell ◽

Wild Type ◽

Megakaryocytic Differentiation ◽

Deletion Mutations ◽

Phd Domain

Abstract Abstract 2393 Somatic mutations of ASXL1 gene have been described in patients with myeloid malignancies and were associated with inferior outcomes. ASXL1 mutations have also been detected in myeloid blast crisis of chronic myeloid leukemia (CML) patients. The mechanisms of acute myeloid leukemia (AML) transformation and functional role of ASXL1 mutations in the leukemogenesis remain to be determined. Recently, we identified PHD domain deletion mutations (R693X and L885X) in patients with CML in myeloid blast crisis and/or AML with minimal differentiation (M0). In the present study, we aimed to investigate the role of PHD domain deletion mutations in the pathogenesis of AML transformation. The K562 cells carrying Philadelphia chromosome, serves as a model to study the molecular mechanisms associated with leukemogenesis. Our result showed that R693X/L885X mutations inhibited PMA-treated megakaryocytic differentiation with the change of physiological characteristic features and suppressed the induction of CD61, a specific cell surface marker of megakaryocytes. We also found that FOSB, a member of Fos family of AP-1 transcription factors was down-regulated in K562 cells expressing R693X and L885X compared to wild-type ASXL1 during PMA-mediated megakaryocytic differentiation. Examination of intracellular signaling pathways showed that the mutant ASXL1 protein prevented PMA-induced megakaryocytic differentiation through the inactivation of ERK, AKT and STAT5 which are required for differentiation. Further, ASXL1 depletion by shRNA in K562 cells led to enhanced cell proliferation, increased colony formation and impaired PMA-mediated differentiation. Previous studies in Drosophila had revealed that Asxl forms the protein complexes of both Trithorax and Polycomb groups that are required for maintaining chromatin in both activated and repressed transcriptional states. By using Western blot analysis, we demonstrated that PHD domain deletion mutations of ASXL1 significantly suppressed the transcriptionally repressive mark H3K27 trimethylation, however no effect on methylated H3K4 (H3K4me2 and H3K4me3), an active histone mark in K562 cells. Co-immunoprecipitation analysis revealed that wild-type, but not PHD domain deletion mutations of ASXL1 interact with EZH2, a member of the polycomb repressive complex 2 (PRC2). Importantly, PHD deletion mutations or downregulation of ASXL1 resulted in the suppression of EZH2 in K562 cells. Our study demonstrated that PHD deletion mutations of ASXL1 resulted in a loss-of-function which exhibited direct effects on the proliferation and differentiation and also proposed a specific role for ASXL1 in epigenetic regulation of gene expression in K562 cells. Disclosures: No relevant conflicts of interest to declare.

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Orlistatand and Rosuvastatin Suppressed Proliferation of K562 Human Myelogenous Leukemia Cell Line through AMPK/Akt/c-Myc Signaling

10.21203/rs.3.rs-18746/v1 ◽

2020 ◽

Author(s):

Behnam Mojjarad ◽

Yaghub Pazhang

Keyword(s):

Cell Cycle ◽

Chronic Myeloid Leukemia ◽

Cell Line ◽

Myeloid Leukemia ◽

Leukemia Cell ◽

K562 Cells ◽

Myelogenous Leukemia ◽

Leukemia Cell Line ◽

Mrna Levels ◽

Hsp 70

Abstract Background: Chronic myeloid leukemia is a myeloproliferative cancer with worldwide incidence, has become as a clinical concern due to chemoresistance in the patients received chemotherapy. Here, we investigated the effect of Orlistat and Rosuvastatin on K562 human myelogenous leukemia cell line in vitro and attempted to illuminate their possible underlying mechanisms. Methods: Cells were exposed to Orlistat and Rosuvastatin, the inhibitors of lipogenesis, then survival and apoptosis rate of K562 cells were examined by MTT assay and flow cytometric analysis respectively. The real time-PCR analysis was used to quantify mRNA levels of Bax, Bcl-2, and Hsp-70 genes. Cell cycle analysis was performed using flow cytometry, whereas the subcellular distribution of c-Myc was measured via immunofluorescence imaging technique. Additionally, the protein level of AMPK, p-AMPK Akt-1, and p-Akt-1 were studied by western blotting. Results: The results showed Orlistat and Rosuvastatin had synergistic anticancer effects on cells and in comparison with the control group, viability and apoptosis rate decreased and increased in treated cells respectively in a dose/time-dependent manner (P<0.05). The mRNA levels of Bax increased while expression of Hsp-70 decreased (P< 0.05). K562 cells treated with Orlistat and Rosuvastatin showed a cell cycle arrest in sub-G1 phase and a decreased level of c-Myc positive cells. Upon outlining the mechanism, it was revealed that AMPK/p-AMPK and p-Akt-1/Akt-1 ratio decreased in treated cells (P< 0.05). Conclusions: Data suggest Orlistat and Rosuvastatin could synergically suppress proliferation of K562 cells through AMPK/Akt/c-Myc axis, proposing a theoretical basis for upcoming application in the treatment of chronic myeloid leukemia

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Vitamin E in Chronic Myeloid Leukemia (CML) Prevention

10.5772/intechopen.96452 ◽

2021 ◽

Author(s):

Lyudmyla Shvachko ◽

Michael Zavelevich ◽

Daniil Gluzman ◽

Gennadii Telegeev

Keyword(s):

Alkaline Phosphatase ◽

Vitamin E ◽

Chronic Myeloid Leukemia ◽

Myeloid Leukemia ◽

Blast Crisis ◽

K562 Cells ◽

Leukemic Cells ◽

Blast Cells ◽

Differentiation Block

The resistance to inhibitors of tyrosine kinase necessitates novel approaches to the therapy of chronic myeloid leukemia (CML). The progression of CML to blast crisis is associated with down-regulation of C/EBP-alpha being involved in the differentiation block in leukemic blast cells. Moreover, lowered C/EBP-alpha expression correlates with resistance to imatinib in CML. We have demonstrated that vitamin E up-regulates expression of C/EBP-alpha and down-regulates expression of Snail transcription factor in K562 cells in vitro contributing to the putative recovery of myeloid differentiation potential. In parallel with increased CEBP alpha expression, Vitamin E treatment results in the decreasing expression of placental-like alkaline phosphatase and increasing expression of tissue non-specific alkaline phosphatase. We suggest that vitamin E could be used as the plausible biological modulator to prevent the progression to blast crisis and to overcome drug resistance of leukemic cells in CML.

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Loss of expression of both miR-15/16 loci in CML transition to blast crisis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2101566118 ◽

2021 ◽

Vol 118 (11) ◽

pp. e2101566118

Author(s):

Francesca Lovat ◽

Pierluigi Gasparini ◽

Giovanni Nigita ◽

Karilyn Larkin ◽

John C. Byrd ◽

...

Keyword(s):

Chronic Myeloid Leukemia ◽

Myeloid Leukemia ◽

Blast Crisis ◽

Chronic Phase ◽

Lymphocytic Leukemia ◽

Oncogenic Driver

Despite advances that have improved the treatment of chronic myeloid leukemia (CML) patients in chronic phase, the mechanisms of the transition from chronic phase CML to blast crisis (BC) are not fully understood. Considering the key role of miR-15/16 loci in the pathogenesis of myeloid and lymphocytic leukemia, here we aimed to correlate the expression of miR-15a/16 and miR-15b/16 to progression of CML from chronic phase to BC. We analyzed the expression of the two miR-15/16 clusters in 17 CML patients in chronic phase and 22 patients in BC and in 11 paired chronic phase and BC CML patients. BC CMLs show a significant reduction of the expression of miR-15a/-15b/16 compared to CMLs in chronic phase. Moreover, BC CMLs showed an overexpression of miR-15/16 direct targets such as Bmi-1, ROR1, and Bcl-2 compared to CMLs in chronic phase. This study highlights the loss of both miR-15/16 clusters as a potential oncogenic driver in the transition from chronic phase to BC in CML patients.

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